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A SailMail Primer


©1998-2015 SailMail Association
This document or portions of it may be distributed in either print or electronic form so long as credit is given to the SailMail Association.

Please send any corrections or suggested clarifications to sysop@sailmail.com .


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This document is intended as a guide for members of the SailMail Association. Subjects covered include advice on equipment selection, installation, getting started with the software and using the system.  There is an extensive section on Frequently Asked Questions and Tips that is useful even to experienced users of SailMail.

To make it easy to bring a copy of the SailMail website on board with you (including this primer), here is a .pdf file of the entire website including all of the application notes.  To save it on your computer,  right click it and then select "Save Target As" and then store it somewhere on your laptop where you can easily find it .  We update the website from time to time, so update your copy occasionally. 

sailmail website.pdf

The SailMail Association is a non-profit association of yacht owners that operates and maintains an email communications system for use by its members.  SailMail email can be transferred via SailMail's own world-wide network of SSB-Pactor radio stations, or via satellite (Iridium, Inmarsat, KVH VSAT, Globalstar, Thuraya) or any other method of internet access.  

The following sections provide detailed information:


o   Overview of the system
o   Choice of Equipment for Accessing SailMail's Radio Network
o   Installation Basics to Use SailMail by Radio
o   Installing and Setting-up the Software
o   Getting Connected Via Satellite or Internet
o   Getting Connected via Radio
o   Sending and Addressing Messages
o   Recommended Operating Practices
o   Frequently Asked Questions, Troubleshooting, Tips, and Trivia
o   Application Notes
o   Glossary
o   Links


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Overview of the Network


The SailMail system implements an efficient email transfer protocol that is optimized for use over communications systems that have limited bandwidth and high latency.  Satellite communications systems and SSB-Pactor terrestrial radio communications systems both have these characteristics.   The SailMail email system's custom protocol substantially reduces the number of link-turn-arounds and implements compression, virus filtering, spam filtering, and attachment filtering.  The combination of the protocol, compression, and filtering dramatically improves communications efficiency.

The SailMail Association maintains its own world-wide network of SSB-Pactor private coast stations in the Maritime Mobile Radio Service.   Email that is sent to a SailMail member's email address can be seamlessly retrieved via SSB radio, via satellite, or via any other access to the internet.

Many budget-conscious SailMail members primarily use SailMail's network of SSB private coast stations to enjoy the most cost-effective email communications worldwide.  Other than the membership fee to join the SailMail Association and the initial hardware cost of a SSB and Pactor modem, there is no cost per message for use of the SailMail radio network.

Other SailMail members use the SailMail's world-wide network of SSB-Pactor radio stations, but also carry Iridium, Inmarsat, KVH/VSAT, or other satellite communications in addition as a backup and for urgent communications in times of difficult HF propagation. 

Finally, some SailMail members primarily access the SailMail email system via their satellite system, taking advantage of SailMail's efficient communications protocol, compression, and filtering to minimize their satellite time and cost.   Some of these members also carry a Pactor modem for use with their SSB as a backup communications system to their satellite system.

In order to send and receive SailMail email messages, you will need Windows compatible computer, satellite or other access to the internet, and/or a marine SSB radio and Pactor modem to access SailMail's worldwide network of SSB-Pactor radio stations. 

It is necessary to install the AirMail software on the member's computer.  AirMail runs on WindowsXP/Vista/Windows7/Windows8/Windows10  and handles message creation/editing. A number of SailMail members successfully run AirMail on Apple computers using Parallels, Virtual PC or similar PC emulation programs.  See the Application note in this Primer for more detail on the use of Apple computers.  The AirMail software is also used by ham radio operators to access the ham Winlink network.  So if you are a ham and also use the Winlink network of ham radio stations,  the AirMail software can be configured to access both the SailMail and the Winlink networks.  

Using Pactor-III or Pactor-4, the SailMail system can pass email messages of a length of up to 35kBytes (17 text pages) and file attachments such as grib weather forecasts of up to 30 kBytes for Pactor-III or 40kBytes for Pactor-4.  If a member is using Pactor-I or Pactor-II, the permitted messages are half the lengths for Pactor-III or Pactor-4, and grib attachments are limited to 10kBytes.  Members are limited to 90 minutes of SailMail station time per week, calculated over the previous week.    There is no limit to the number of messages that can be handled over satellite or other internet access.


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Choice of Equipment for Accessing SailMail's Radio Network


Three components are needed to use SailMail's worldwide network of SSB-Pactor radio stations: a marine SSB transceiver (and antenna), a Pactor-modem, and a computer with the appropriate software. The Pactor-modem is the only specialized piece of equipment, and is essentially a specialized modem designed for radio communications. The Pactor-modem generates the audio signals that are sent via the radio transmitter, and decodes the incoming audio signals from the radio receiver. The primary connections between the Pactor-modem and the radio are two audio signals (audio in and audio out), plus a PTT (push-to-talk) signal to tell the radio when to transmit 



Transmitting and receiving digital signals is similar to voice, and most modern marine SSB radios will do the job.    For comments on various marine radios used by SailMail members, see the application note on radios in the Application Notes section below.

The second issue is the transmitter's ability to transmit a continuous full-power signal without damage.  Some recent transceivers can do this without a problem (e.g. Icom M710, M700-Pro, M802), but many older transmitters will have to be operated at a reduced power setting.  If you are buying a SSB and intend to use SailMail, choose a radio that can transmit data at full power.


The Pactor-modem:

SailMail works best with the SCS Pactor-IIIusb or P4dragon modems

SailMail also works with the older SCS PTC-II, IIe, IIex,  IIpro, or IIusb modems, but if you have or buy an older modem make sure that it is licensed to use the Pactor-III mode, and make sure that your computer can can set your SSB frequency, which requires special cables for the modem, or an extra USB adapter for the IIex modem.    We strongly encourage all members to use Pactor-III mode.  We support Pactor-4 at all stations but expect that Pactor III mode will continue to be used by most SailMail members because of the significantly lower cost of the modem. But for those with greater communications needs, Pactor-4 offers a good way to increase capacity.   For details on older SCS modems, if you are considering a second hand unit, see the FAQ section below.


The Computer:

Any computer that can run WindowsXP/Vista/Windows7/Windows8/Windows10 will do the job.  Members with Apple computers have successfully used SailMail and the AirMail software by using Parallels, Bootcamp, or Virtual PC, depending on their preference and age of their Mac.  See the application note on Mac computers.  Most recent Windows computers and Apple computers do not have a 9-pin serial ports, and so will require a USB-Serial converter.  For more detail on adding a serial port see the application note on serial ports or send a blank email to serialports@saildocs.com


Other Requirements: 

Besides a HF modem, radio, and computer, your on-board station will require a reliable source of 12-volt power and a good antenna. A marine SSB transmitter draws around 20 amps when transmitting at full power, and sending email requires a lot of full-power transmitting.  A full page of text is about 2000 characters which takes less than a minute using Pactor-III on a good day and somewhat less using a P4dragon  in good conditions.  Not a big number in terms of amp-hours, but if your batteries or wiring aren't up to the task then you will have problems that may be very hard to identify.  Additionally, be sure that your batteries are fully charged PRIOR to using the SailMail system; marine SSB's are very intolerant of low voltages, particularly when sending data.


Antenna and ground: 

Antenna installation is another important topic and a good ground system is absolutely critical.   The most important aspect of a radio installation is the ground connection from the antenna tuner; this is the worst place to cut corners. The standard antenna arrangement for a sloop is to use an insulated backstay driven by an automatic tuner.  The antenna tuner is typically mounted under the deck near the backstay, and is grounded to the keel with a 3" copper strap.  Additional 3 inch wide copper straps should also connect to nearby metal, such as stern pulpit, metal tanks, and the engine. Keep electrolysis in mind, and remember that radio ground tapes from antenna tuners can incorporate series capacitors that will block any DC electrolytic or galvanic currents.  See the West Marine Advisor article on grounds.  There is a copy of that article attached as an application note to this primersailmail.com/grounds.htm  

Common mistakes are using a ground wire instead of a strap,  a ground system that doesn't connect to enough metal, or an antenna lead wire that is run right alongside a backstay below the backstay insulator. The latter problem is very common and shunts a large part of your signal to the ocean, so put the lower antenna insulator at the extreme lower end of the backstay right above your turnbuckle or backstay adjustor.  Then use plastic tubing to insulate the lower part of the backstay (above the insulator) that is within the crew's reach.  Radio waves propagate just fine through the plastic tubing, but the plastic tubing will protect your crew just as well as the insulation on the feed wire would have.  The fact that you don't have the feed wire running near a grounded backstay will dramatically improve your radio's efficiency.

Some folks ask if there is any magic length for a backstay antenna.  The answer is "yes and no."  In general longer is better, and unnecessary wire or rod terminations are bad, so often the best approach is to have the top insulator right at the masthead, and the bottom insulator right at the top of the turnbuckle or hydraulic backstay adjuster.  This eliminates four wire terminations (which are potential failure points for your rig) and gives you the longest antenna.  There is a wrinkle (as always).  Base loaded vertical antennas are hard to efficiently load if their length is an even multiple of 1/4 wavelength (e.g. 1/2 wave, or 1 wave, or 3/2 wave ...).  Therefore if you are also a ham, and 14.313 MHz is really important to you, avoid those lengths.  A 1/4 wavelength in feet is 234/(freq in MHz), so a 1/4 wavelength at 14.313 MHz is 16.35 ft.  Therefore, if you are a ham, avoid having a backstay antenna that is 32.7 feet or 65.4 feet long.  If you are not a ham and just use SailMail, then just go with the "longer is better", and "fewer swedge fittings are better" principles and put your insulators at the top and bottom of your backstay and avoid four terminations.  There are enough SailMail frequencies so that if your tuner has trouble tuning your backstay at some frequency because you happened to end up at exactly 1/2 wavelength, there will be other SailMail frequencies on which it will work fine.  Remember when working out the length of your backstay antenna, you start measuring right at the tuner, and you include the length of the feed wire that connects to the backstay in your measurement.

Having read all of the above paragraph, remember that the most important part of your antenna installation is the ground connection to the tuner.  That is the best place to invest your energy to have a SSB that works great.

If you don’t have a backstay, then a 20+ foot marine whip antenna will work fine, again with an automatic tuner and a great ground on the antenna tuner.



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Installation Basics to Use SailMail by Radio


This section describes the simplest way to get on the air and try out SailMail, which is to use your SSB in USB mode, just like you do for voice.  If you use SailMail for more than just occasional use, and have a SSB that is capable of having its frequency set by your laptop, you will certainly want to enhance your setup to allow your laptop to remotely set the frequency on your radio.  Marine SSB's that are capable of having their frequency remotely set by the AirMail software include the Icom M710, Icom M700pro, Icom M710RT,  Icom M802, SGC SG-2000, SEA-235, and Codan-9390 radios.  To set up your radio to be remote controlled, you will need an additional wire to the radio's control port, either from a second serial port on your laptop (if you use a SCS PTC-IIex or IIe), or directly from your HF modem (if you wisely use any of the other SCS Pactor modems).  Details of remote control for radios that are capable of being remote controlled are available in the help files that are part of the AirMail software, so go ahead and download and install the AirMail software and take a look.  There is also some information in the  Application Notes section of this Primer.  If you are getting a dealer to set you up, get the dealer to configure the remote tuning right away, supply the extra wire (with ferrites), and show you the ropes.  If you are sorting out your installation yourself, you can first try out SailMail using the regular old voice USB mode as described below, and then as you build confidence, look up the appropriate application note and set up the remote tuning from your laptop.

There are three cables required to get your HF modem hooked up (not counting the remote tuning cable): a data cable between the HF modem and the computer, an audio/PTT cable between the HF modem and the radio, and a power cable to a 12-volt supply (note that it is possible to wire Icom radios to power the HF modem through the audio cable). The data cable sometimes comes with the HF modem or can be purchased at the computer store.  Recent modems use a USB cable whereas older modems have a 9-pin female D connector with a pin-out designed to connect directly to the 9-pin male D connecter that will in turn need a USB adapter to connect to your computer

The audio/PTT cable will have four wires: transmit audio from the HF modem to the transceiver, receive audio from the transceiver to the HF modem, a push-to-talk (actually "ground-to-transmit") connection, and ground. The cable must be shielded, with the shield connected to the connector shell at both ends. The pin connections are different for each HF modem and each radio, so generally a cable must be made up specially for each configuration. If the radio has a rear-panel "Accessory" connector then that should be the first choice, otherwise the front-panel microphone connector can be used as an extremely undesirable second choice. An accessory jack provides line-level input and outputs and (on most radios) disables the microphone when the rear-panel "PTT" connection is activated.  This cable (as with all others) must have clip-on ferrites at both ends.  Some radios have 12 vdc available at their accessory jacks (e.g. Icom M710, M700pro, M710RT, M802).  If you use one of these radios, it is convenient to have the modem be powered directly from the radio.

Whatever connection you use, be sure that the transmitter audio is not being over-driven.   The modem can be adjusted from the AirMail software, and default settings in AirMail are ok for many transceivers.  If, however, your radio is only designed for voice duty, (e.g. SGC SG-2000, SEA-235 ) it is worth checking that the radio is not being over-driven, which could cause it to overheat. For instructions on how to check and set the drive levels to your radio, see the Application Note on Setting Drive Levels, in the Application Notes section of this Primer.

The SCS modems use an 8-pin DIN connector for HF audio connections, although all of the useful signals are on pins 1 to 5 so a 5-pin DIN connector will work just fine. In fact, the German pin layout for an 8-pin connector does not match the geometry of the American pin layout, so if you melted the original connector trying to solder it then a 5-pin connector is the easiest replacement. The 5-pin connectors from Radio Shack also don’t melt as easily as the German ones.  A good trick is to also buy a female connector, and plug the male connector into the female connector to hold the pins straight while you are soldering it.  The pin numbering for DIN connectors is inconsistent, so check the PTC-II manual carefully for the pin locations.

Many marine electronics dealers sell pre-assembled cables for many common radios (e.g. Icoms).  If you are using an Icom M710, M700pro, M710RT, or M802, just buy a pre-assembled cable.

The relevant connections on the  PTC-II HF modem are as follows:   For more detail see the help files in the AirMail software. 

Pin 1Transmit audio (TxD) from the HF modem to the transmitter
Pin 2Ground (audio signal return)
Pin 3Push-to-Talk (PTT), connect to ground to transmit
Pin 4Receive audio (RxD) from the receiver to the HF modem
Pin 5Power supply input to PTC-II (alternative to pin jack)
shellcable shield

These signals, or something equivalent, will be present on the transceiver's rear-panel accessory connector or front-panel mike and speaker jacks, so simply match up equivalent signals (and keep a drawing of how you did it!).

A few comments on RFI: A transmitter putting out 100-150 watts in digital modes can generate quite a bit of stray RF, which often finds its way into the HF modem and computer cables and raises all sort of havoc. A good ground system and shielded cables with clip-on ferrites installed are essential.  It is always necessary to use clip-on ferrites, and a coax line isolator (next to the tuner in the coax that leads to the radio) to block RF interference.  So save yourself time and aggravation by purchasing 12 clip on ferrites and one line-isolator from the vendors mentioned below, and install them when you install and set up your modem. 

Ferrite chokes come in two useful sizes: one is about 1" long with a 1/4" hole through the middle, and the other is about 1" long, with a 1/2 " hole through the center.  Ferrite chokes act as RF blocks, allowing intended "differential-mode" signals to flow, but blocking any undesirable common-mode RF currents.   Their primary function is to break up RF ground loops and keep RF current off of  cables where RF interference can couple into everything.  You should clip a ferrite choke onto both ends of the wire between the laptop and the Pactor-modem, onto both ends of the wire between the Pactor-modem and the SSB, onto both ends of the tuner control/power wire between your tuner and your SSB, and finally onto both ends of the antenna coax between the SSB and the tuner.  If you have a remote control wire between a SCS PTC-II and your SSB, or between a second serial port on your laptop and your SSB, there should also be a ferrite choke on both ends of this wire.   Most installations also benefit from ferrites clipped onto the power wires to the SSB and to the Pactor-modem.  If your SSB interferes with your autopilot, try clipping ferrites onto both ends of all of your autopilot interconnections.  The ONLY place that you SHOULD NOT clip a ferrite choke is onto the antenna lead-in wire between the High Voltage output of the antenna tuner and your backstay or whip antenna; the common-mode RF signal in this wire IS the intended signal, and must not be attenuated.   Ferrites nearly always help, and in any event can do no harm, on all other wires.

Ferrite chokes with a 1/4 " hole are available from Radio Shack, or from any of the Marine Electronics Dealers listed on the opening page of the SailMail website.  Another source of high-performance type-31 ferrite chokes is  The Radio Works (www.radioworks.com) 800-280-8327.  They come either with a 1/4" hole for $2 each, or with a 1/2" hole for $4 each.  The chokes with a 1/4 " hole look neat when clipped onto the SSB and laptop wires, but the 1/2 " hole chokes allow you to put multiple turns of the wire through the choke, which is multiple times more effective.   The 1/2 " hole choke is generally required to fit on the tuner control wire, the SSB power wire, and the antenna coax between the SSB and the tuner.   When you clip on a ferrite choke, it is essential that there is no air gap between the two halves of the ferrite.  If your ferrite will be a permanent installation, the best practice is to remove the two halves of the ferrite choke from the clip-on plastic case, mate the two halves around your cable, and then tightly tape the two halves together with stretchy plastic tape.  This technique ensures that the two halves of the ferrite are tightly pressed together with no air gap between them.  If you are neat and careful with the taping, the result can look very professional or you can snap the cover on over the tapeAgain, get a dozen snap-on ferrites.

A ferrite Line Isolator is highly recommended to be put in the coax between the transceiver and the tuner (ideally near the tuner). A Line Isolator is a much beefier version  of a clip-on ferrite choke (about ten times more effective) and blocks the stray RF path to ground via the coax shield and transceiver ground, forcing the antenna currents to use the proper ground strap that is connected to your antenna tuner.   An excellent Line Isolator is model T-4 (ungrounded version) which costs $30 from The Radio Works (www.radioworks.com), 800-280-8327, their web site also has an excellent discussion on grounding and RF interference.  Also,  be sure to put two or more clip-on ferrite chokes on the tuner control/power wire, some near the tuner and others near the SSB.   


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Installing and Setting-Up the Software


We assume that you are running WindowsXP/Vista/Windows7/Windows8/Windows10 

HAMS read this!  If you are a Ham, and want to use AirMail for both Ham use and SailMail use, you should download and install the SailMail Version by following a link from the download page of this website.   Your Ham setup will not be affected, but by downloading and installing the SailMail Version in addition to the Ham Version, some additional files and configurations will be installed so that you will be able to use SailMail as well as Winlink from the same AirMail installation.  

For more info on using Airmail with both ham and Sailmail, send a blank email to: bipolar@saildocs.com

The download version of AirMail is packaged as a self- extracting "Zip" file,  which is available by following the links from the Download Page on this website.  If you already have a previous version of AirMail installed, when you run the download file it will upgrade your previous version of AirMail, and will preserve your settings and address book.

To uninstall AirMail, simply delete the files and folders under the C:\Program Files\AirMail folder. 

Start AirMail and answer the initial questions, providing your marine callsign which should look something like "WXY1234". 

Once the AirMail software in installed, if your computer has access to the internet, you can go ahead and try connecting to SailMail via the internet.  In the Message Index Window, click the "Internet" button, which looks like a lightning bolt.  Then click the "connect" button, which looks like a green ball.  You system will send and receive any messages just as if you were connected via radio. 

Next do the rest of the radio-related installation...

Before doing anything else, go to Tools/Options on the menu and check the settings. Most of the settings described below should be preset for you in the initial settings of AirMail, but you will need to at least enter your Pactor-modem type.

On the connection page in the Modem Connection section, select the appropriate Modem type and check that the com port and baud rate are correct (we recommend 57600 for the PTC-II). In the Radio Connection section select the appropriate option for the remote control of your radio, which is described in the Application Notes for particular radios.  In the Audio Tones section the Center Frequency should be "1500".   For the most straight-forward initial setup, put a dot next to USB, and use the radio  in USB/J3E (normal voice SSB) mode.  Leave the Amplitudes set to their default for now.   If you are not sure what you are doing, or how your radio should be set up and connected for remote control, then get help from your marine radio dealer (and pay him or her for the time).   Leave the settings under the Advanced button as they are.

On the settings page you should see your marine callsign under the SailMail tab.   Enter your SailMail Password in the "System Password" box.  SailMail Passwords ARE case sensitive, so enter it carefully.   Leave the settings under the Advanced button as they are.

Don't make any changes to the folders page or routing page.  AirMail will create a set of message folders when it starts, for incoming and outgoing messages, and a "saved" folder.  It is recommended to use the defaults.

Click the OK button (not cancel) to close the Options Window and save the settings.

Now open the Terminal Window (click the right-most "Terminal Window" button which looks like a blue globe). Watch the upper screen - after 2-3 seconds it should show a list of setup commands in red - these are the "Link Messages" that you elected to show in the Tools/Options/Connection Window.  If all that worked then you should be ready to connect.   If that didn't work, your laptop and Pactor-modem are not talking to one another and you need to re-initialize your Pactor-modem, fix your cable, and/or sort out your COM port, BEFORE proceed with these instructions.

In the Terminal Window in AirMail, you will notice two or three pull down menu's, the third from the right (if you have it) should remain set to SAILMAIL and the second from the right should be set to  the SailMail station that you want to connect to.   The right window selects the frequency. 

If you have connected your radio for remote-control, the frequency selection in the right menu will adjust the frequency on your radio.  If you have not yet connected your radio for remote control then the frequency selection in the right menu will not do anything and will not change the operation of AirMail.    You can, however, select the desired frequency in the right menu, and then refer to the frequency at the bottom of the Terminal Window in order to let AirMail calculate for you the frequency that your radio should be set to.  Refer to the application notes for more information on having the AirMail software remote control your radio, which is a huge convenience.  


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Getting Connected Via Satellite or other Internet Access


First, make sure your computer has access to the internet via Iridium, Inmarsat, KVH/VSAT, Globalstar, Thuraya, cellular data networks, WiFi, or any other method including plugging into an ethernet cable at your desk.  One quick way of testing that your internet access is working is to open www.google.com in your browser.  Once you are certain that you have access to the internet, in the Message Index Window, click the "Internet" button, which looks like a lightning bolt.  Then click the "connect" button, which looks like a green ball.  You system will send and receive any messages just as if you were connected via radio. 

For details on how to set up your computer and AirMail installation to use the Iridium PPP Data Service, see the notes at:  www.saildocs.com/sailmail/iridiumPPP.txt   You can also request an email containing this document to be sent to you by sending a blank email to iridiumPPP@saildocs.com



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Getting Connected Via Radio


The next step is to set the transceiver for an appropriate frequency.  For short range, pick a lower frequency (e.g. 2MHz or 5MHz).  These low frequencies will work up to a few hundred miles in the daytime and up to one thousand miles at night.  The intermediate frequencies (e.g. 7MHz) will work up to several thousand miles at night.   The high frequencies (e.g. 10, 13, 18 MHz) are best for the longest distances, many thousands of miles, during the daytime.  

Be sure that the "Clarifier" (sometimes also called "Clarity" or "RIT") is either turned off, or is in its centered "detent" position


SailMail Frequencies:

The frequencies listed below are the Designated Center Frequencies from SailMail's stations.  These are the frequencies that should be visible in the right-hand window on the top of your terminal window in AirMail.    If you are using regular old USB mode (same as for voice) then you need to subtract 1.5 kHz* from the frequencies below in order to calculate the frequencies to enter into your radio.  As mentioned, AirMail can do the subtraction for you, look at the bottom of your terminal window.

* This assumes that you have your modem tones set to a center frequency of 1500 Hz (recommended).  If under tools/options/connection you have center frequency set to 1700, then you need to subtract 1.7 kHz to calculate the dial frequency to set your radio to in USB mode.

Every SailMail station provides service in Pactor, Pactor-II, Pactor-III, and Pactor-4.    SailMail's stations and their frequencies are as follows:


Location Callsign Frequencies in kHz
California, USA
WQLI952 5881.4, 7971.4, 10343, 13971, 13986, 18624, 22917.4
San Diego
California, USA
WQAB9642759, 5740, 7380, 10206, 13874, 18390, 23060
Friday Harbor,
Washington, USA
WHV382 2794.4, 5830, 7995, 10315, 13940, 18277
Hawaii, USA
KUZ533 2701.4, 5836, 7957.4, 10325, 13930, 18264
South Carolina, USA
(three transceivers)
KZN508 2656.4, 5876.4, 7961.4, 7981.4, 10331, 13998, 18618, 18630
Nova Scotia, Canada
XJN714 4805, 7822, 10523, 13937, 14436.2, 18234, 21866
NSW, Australia
(five transceivers)
VZX 2824, 4162, 5085.8, 6357, 8442, 8684.5, 10476.2, 12680, 13513.8, 14436.2, 16908, 18594, 22649
Maputo, Mozambique, Africa RC01 5212, 7957.4, 10335, 10522, 12689*, 12694, 13930, 13992*, 14588*, 18264, 18630*, 22212*   (*these frequencies use a directional antenna pointed NE into the Indian Ocean)
Brunei Bay,
Brunei Darussalam
(four transceivers)
V8V2222 5212, 6305, 7962, 8399, 10323, 11174, 13426, 14987, 16786, 18893, 20373, 22352
Brugge, Belgium
(four transceivers)
OSY 6330.5, 8422, 12580.5, 16684.5
Corpus Christi,
Texas, USA
WPTG3852720.8, 5859.4, 7941.4, 10361.4, 13906.4, 13926.4, 18376.4, 22881.4
HPPM1 4075, 5735, 8185, 10450, 13880, 18240, 18440, 23050
HPPM2 2650, 5870, 10329, 13980, 18610, 22643
Los Lagos,
CEV773 2828.5, 5266.5, 10620, 10623, 13861.5, 13875
9Z4DH 2212, 5005, 7405, 10150, 13548, 17103, 18172, 20528
Manihi Atoll,
Polynésie Française
FOHXM 1919, 4206.5, 6222.4, 8289.4, 12576, 16785.5
Niue ZKN2SM 4168, 6241.5, 8308.5, 12373.5, 16563.5, 18856.5


(if members want to receive an email that will automatically update the information on SailMail stations and frequencies that is kept in their AirMail software, send an email to stations@saildocs.com)


Use your radio in USB (J3E) mode (the same mode as for voice)Some radios have an "email" mode that enables a narrow band filter.  This is intended for older SITOR systems; do not use these modes for SailMail.  Instead just set your radio in regular voice USB (J3E) mode.  You must subtract 1.5 kHz from the above frequencies in order to work out how to set the frequency on your radio.  For example for the first frequency listed for WRD719, a radio in USB mode would be set to 13984.5 kHz (13986 minus 1.5).  AirMail will do this subtraction for you and you will see the frequency for your radio to be set to along the bottom of your terminal window.

If you do not have AirMail set up to remote set the frequency on your radio, and you want to program SailMail's frequencies into the memories of your radio, then either step through the frequencies in the terminal window and get AirMail to do the subtraction for you, or carefully sharpen your pencil, do the subtractions, and double-check your work.   Enter these frequencies very carefully into the memories of your radio, following the instructions supplied with the radio.   Be very careful, it is a fool's errand to try to connect to SailMail on the wrong frequency.   If this doesn't make any sense to you, get some help from your marine radio dealer.

Some marine radios are delivered in a configuration in which they may not transmit on the SailMail frequencies.  If you find that your radio has these "lock-outs" then you will need to arrange for a licensed marine radio technician to change the configuration of your radio.  If your new radio is an Icom M802, read the application note on the M802  that is on the SailMail website.

Go to the terminal window by pressing the button with the blue globe in it.    In the terminal window, check that the "handshake" button is pushed inCheck that your "clarifier" is centered.  Check all of the frequencies, if you hear a periodic "chip, chirp" or a periodic "rasping" sound at 2-4 second intervals, that's somebody else using the station.    Listen carefully, and when the station is idle then click the left-most green button (from the Terminal Window).  The HF modem will call for about a minute before timing out, that is usually plenty if the propagation is good and the station is not busy on another frequency. If there is no answer then try another frequency or try some other time - it may be busy on a another frequency or there may be no propagation.  While calling, if your radio is not clicking to transmit mode at 2-4 second intervals, then your Pactor-modem and radio are not talking to one anotherCheck the cable from your Pactor-modem to your radio.  Similarly, the red LED's on your PTC-II should be flashing with the noise and signals received from your SSB when receiving.  If the LED's are not flashing, then there is likely a bad connection in the cable from your Pactor-modem to your radio.

If your radio is clicking between transmit and receive when calling, check that your radio is drawing an additional 10-15 amps from your 12 volt system when it is transmitting.   If the radio isn't drawing an additional 10-15 amps when transmitting, then your modulation levels are not set correctly or your tuner/antenna/ground system is faulty and your radio can't transmit at a reasonable power level because the tuner is unable to provide a good "match" to your radio

When you get connected you will see the welcome message. If things are working correctly then your computer will respond with your callsign and exchange any email that is ready to go in either direction, and then disconnect. If you got this far, then all of the technical stuff is working, the wires are all hooked right and you figured out the frequencies correctly, congratulations.

If the Pactor-modem is not working properly, your problem is likely either with communications between your laptop and Pactor-modem, or with the connection and configuration between the Pactor-modem and your radio.    If the Pactor-modem did not initialize properly when you opened the Terminal Window in AirMail (i.e. its lights flashed etc), then the Pactor-modem may be configured in a way that is incompatible with AirMail, or your com port may not set up correctly

If the Pactor-modem IS responding to commands from the computer,  but the radio isn't responding and transmitting when you try to connect, then your radio interface is probably the problem.  If you cannot fix the problem by carefully reading these instructions, or comparing notes with another SailMail user with a similar configuration, then you should track down a marine radio dealer and pay for some professional help. 

If the modem is responding to the computer, and radio is switching between transmit and receive, check that your radio is drawing 10-15 amps more on transmit than on receive when calling on SailMail.  If it doesn't, try your radio on voice.  If you give a brief whistle into the mic when using your radio on voice (on a clear channel after identifying yourself and announcing that you are testing), your radio should draw 15-20 amps from your 12 volt electrical system.  If it doesn't you likely have a tuner/ground/antenna connection problem.  If the radio draws 15-20 amps when you whistle into the mic, but doesn't draw 10-15 amps when transmitting via Sailmail, then you likely have a connection problem to the modem, or your modulation levels are set incorrectly.

If you got this far then try composing a couple of test messages. Do this by going back to the main window (F6 to switch or close the Terminal Window by clicking the "X" in the upper right corner) and click the "Format a New Message" button (all the buttons have "hints" if you pause the cursor over the button for a moment). For the first, choose "sysop" from the address book and click "OK."  In the To: field should be "sysop@sailmail.com ".  In the Subject: line type "first test message.".   The lines below the subject make up the body of the message. Send a message to SailMail sysop saying that you figured it out and can now send and receive messages via SailMail.   Click "Post Via" if necessary to set the adjacent box to SAILMAIL.  (If a "dialog box" appears, check the box to "always use this path for Email.")  Finally, click the "post the current message" button  to post the message for sending (the button looks like a postbox). That will save the message and mark it for sending, and return you to the index.  Your new message should be in the index with a "postbox" icon next to it indicating that it is posted waiting to be sent.

Now go back to the Terminal Window (F6 or globe button).  Check that the "handshake" button is pushed in, and the clarifier is set to center.   Listen, and if the frequency is clear, reconnect to the station as before, and this time your messages should be uploaded to the SailMail station.  SailMail will disconnect automatically when done.

If all that works then your HF modem is wired right and your transceiver is working. If there are performance or other problems then carefully re-read the section in this Primer titled, "Installation Basics" and read the section titled, "Frequently Asked Questions, Troubleshooting, Tips and Trivia" below.



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Sending and Addressing Messages


Be extraordinarily careful when you address your messages, and double-check the internet email addresses before sending.   Many messages sent by new SailMail members never make it because they are not addressed correctly.  In some cases you will not receive a "bounce" message in response to an incorrectly addressed outgoing email; it will simply vanish.   Don't guess at friends' email addresses; instead, send an email to a mutual friend and ask for the correct email address. 

Internet addresses always include an "@" sign, never have spaces in them, and generally end in ".com", ".org", ".gov", or ".edu" unless they are going to a non-USA based web server, in which case they often end in a two digit suffix that identifies the destination country (for example ".nz" for a message to New Zealand, "au" for Australia, "fr" for France, etc).


To Send a Message:

  1. In the Message Index Window click the "Format a New Message" Button.
  2. You will see the Address Book, if there is no entry for your recipient, click "New" and then fill out the form, setting "Email Gate" to EMAIL, and "Post Via" to SAILMAIL. Click OK.
  3. In your message, make sure that "Email Gate" is set to EMAIL. and "Post Via" is set to SAILMAIL.  (NEXUS also works ok for "Email Gate".)
  4. Put only one internet address on the To: line (replacing any template chatter).
  5. You can put multiple internet addresses on the cc: line, with each address separated by a COMMA.  
  6. Type your message into the window below the subject line.
  7. To post the message, click the Post Box button (Post the current message).
  8. To send the message, go to the Terminal Window (press the blue globe button), check that the "handshake" button is pushed in,  LISTEN, and if the frequency is clear, click the green button.

Remember that all internet addresses contain exactly one "@" sign, contain no spaces, and have at least one "." to the right of the @ sign.  Carefully check your To: and CC: addresses.

Messages sent from the internet to your boat should be addressed:
Where CALLSIGN  is your boat's marine callsign which should look something like WXY1234 

Encourage your correspondents to carefully address their email to you.  If they send email to your SailMail address and they incorrectly type your callsign, they may not receive a "bounce" message, depending on their typo. 

It generally takes about an hour for email to get between the internet and the SailMail station in either direction, so be patient.  If you send a message to yourself for test purposes, it may take up to two hours to re-appear on the station for download



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Recommended Operating Practices


LISTEN FIRST.  Before you transmit, be sure to listen carefully to be sure that there is no traffic in progress.  Sometimes the chirps  or periodic rasping sounds only come at 4 second intervals, so listen for a while.   If there is traffic on frequency, you will not be able to connect, and your attempts will just delay the traffic that is already underway for the duration (1 minute) of your call.   There is no "free-signal".   Specifically, if you hear "chirping" or a periodic "rasping" on a SailMail frequency then the station is in use; DO NOT TRY TO CONNECT. 

Keep in mind that the SailMail stations (with certain exceptions such as KZN508, VBV2222, OSY, and VZX) have just one transceiver that scans the frequencies looking for a call.  These stations therefore can only handle one connection at a time.  Many members find it convenient to tune around and listen on all of the frequencies assigned to the station that they want to connect to, to see if the station is busy.  If they hear that a single-radio station is busy on a frequency, it is fruitless to call that station on another frequency (it doesn't cause interference, it is just pointless).  Instead,  wait until the station is open, and then call on whichever frequency that you figure will work best.  If a station is too busy, consider trying another station.  If you connect in the late afternoon or evening at a higher frequency, you can connect to stations that are quite far away.

If you tune around and do not hear a single-radio station, go ahead and try to connect.  If the station does not respond it is either because the station is busy on a frequency that you cannot hear because there is no propagation to you at that frequency, or it could be because there is no propagation at the frequency on which you are calling.  If you are trying to connect to a multiple-radio station, just listen to make sure that your frequency is not in use, and then try to connect.

Not listening first, or attempting to connect to SailMail on a frequency that is already in use, is counter-productive, lubberly, pointless, rude, un-shipmatey, and violates International Telecommunications Law (as well as common sense).  We are open to creative suggestions for ways of further clarifying this point.

It is ok to call on a frequency where a station is just finishing a connection.  Be aware, however, that just because you hear the station identify itself in Morse code, the connection may still be in progress.  The stations transmit their identification in Morse code itself every 7 minutes DURING a connection as well as at the end of the connection.  If you call on a busy frequency, when another member is connected to the station, you will not be able to connect and your attempt may delay the traffic that is already underway.  Your fellow SailMail members will be able to identify who you are, and you will be known forevermore as a heel and a lubber.  Net, DO NOT call when the station is busy, and DO NOT reflexively call when you hear a Morse ID.  Instead, wait to make sure that it is the end of your fellow member's connection before you call.

If you are connected to a SailMail station and some thoughtless heel tries to connect during your connection, do not disconnect.  Let your connection continue.  If you are using Pactor-III or Pactor-4 your connection will typically not be interrupted.

If you do not have AirMail set up to remote-control your radio, then be sure to program all of the SailMail frequencies into adjacent memories in your radio.   This makes it easy to just scan around to see what the stations are doing.  Again, the single-radio stations can handle only one connection at a time, so if a single-radio station is busy on one frequency you will not be able to connect by calling that same station on another frequency.

Be extraordinarily careful when you address your messages, and double-check the internet email addresses (including the "cc:" addresses) before sending.   Many messages sent by new SailMail members never make it because they are not addressed correctly.  In some cases you will not receive a "bounce" message in response to an incorrectly addressed outgoing email.  Don't guess at friends' email addresses.  Instead, send an email to a mutual friend and ask for the correct email address. 

Fully charge your batteries JUST PRIOR to using SailMail.  Marine SSB's are intolerant of even slightly low battery voltages, particularly when sending data.   By trying to connect to the SailMail station with anything other than batteries that are fully charged, you are wasting your own time and batteries, as well as using more station time than is necessary.  You will occasionally hear vessels whose signals sound garbled or distorted (unsuccessfully) calling the SailMail station.  This garbled sound is nearly always caused by calling with batteries that are not fully charged, but can also be caused by RF getting into the Pactor-modem/radio wires or by over-driving the radio.

The system automatically computes a running average of your connect time over the last 7 days.  Limit your usage to a running average of 90 minutes per week.

Carefully control access to your SailMail email address.  Give it only to responsible friends and family members.  Explain to them that the SailMail system sends email VERY SLOWLY and devastates your onboard batteries, and they should only send you important and brief email messages.

NEVER post your SailMail address on a website.  If your SailMail address does get posted on a website, it will get "harvested" by the "trawling" programs that spammers use to find email addresses from the web, and you will start to receive spam messages within a day or so. 

Instruct your correspondents not to forward to you Internet jokes and frivolous emails.  Forbid them from putting your SailMail address on chain-emails, jokes, postings to Internet news-groups, websites, or widely cc'd emails that will attract SPAM to your SailMail address.  If your SailMail address ends up on SPAM mailing lists, your SailMail account will become useless because it will become too time consuming for you to download all of the SPAM in order to get to the few messages that you really want to receive from close friends and family.  If you maintain a website with your cruising newsletters, do not allow your SailMail email address to be visible on the website.  If it is, it will end up on SPAM mailing lists.  Before you joined the SailMail Association, there was never a single SPAM email sent to your SailMail address, and the SailMail Association never releases any member's email address to anyone.  If SPAM starts, it is because of something that you or one of your correspondents has done.  If one of your correspondents does err, and your SailMail account does end up on the SPAM lists, contact sysop@sailmail.com and we can change your SailMail email address.  This will require you to inform your (desirable) correspondents of the new address.   It is far preferable, however, to avoid the problem in the first place.

If you want to distribute email newsletters to multiple email addresses, designate a close friend to act as an Internet postman.  Send one copy of your newsletter to your "postman" and let him or her forward your email newsletter to a list of email addresses (and/or post it on your website, after having first removed your SailMail address).    Internet addresses tend to change frequently, and email messages sometimes bounce even when the address is ok.   It is far easier for your Internet Postman to deal with these bounce messages than it is for you.   If you send your newsletter directly from SailMail with lots of cc's, you will have trouble interpreting exactly whose addresses bounced, given the abbreviated bounce messages that the SailMail system returns to you.  Further, the bounce messages will use your connect time and batteries needlessly.   Even less efficient than sending multiple cc's from SailMail is the practice of sending identical messages one-at-a-time to different addresses from SailMail.    This practice uses station connect time to send each copy of the message.   Some folks apparently do this because they feel that their correspondents might feel slighted to just appear on a cc: list.  Instead of sending individual messages, explain to your correspondents that you are using a bandwidth constrained system and sending cc's is the best that you can manage.  If your friends still have their noses out of joint, find new friends.  You might also consider using SailMail's relay service.  For information send a blank email to relayinfo@saildocs.com

Keep a regular internet email account, and use it as your primary email address for all but your closest friends and family.  Use this regular account for long or non-time-critical messages and for using as a return address when ordering items via the Internet.  If you want to post an email address on a website, use this (non-SailMail) address..  You can check this address from time to time when you have regular access to the internet (internet cafe's work, as do phone lines of friendly harbormasters etc.).  Have your friend who is acting as your Internet Postman check this account occasionally and forward important messages via SailMail.  If you are cruising internationally and want to access your normal internet account via the web only via internet cafes, setup a free email account with www.gmail.com .  Use your regular internet account whenever you have to give an email address to a business.  Many businesses sell email addresses onto the spam lists, and if this happens to your SailMail address, you will have to change your address, as described above, to stop the spam.

Under NO circumstances should you set up your regular email account to automatically forward messages to your SailMail account.  If you start to receive lots of unwanted messages, your SailMail account will become saturated and you will not be able to use SailMail to send and receive the messages that you really care about.

Inform your correspondents that the Internet, HF communications, and computers on sailboats, are not particularly reliable, and so if they stop hearing from you during a passage they should not panic and they should not call the Coast Guard or other authorities.  If the Coast Guard calls them, however, inquiring about your whereabouts and why your (registered 406) EPIRB is going off, THEN they should panic.

When you are in a major marina use  internet access via your boat computer, or use "Webmail" via a public computer  to retrieve your SailMail messages at an Internet Cafe or other location where you can get access to the Internet.  When your vessel is in a marina your SSB will work poorly due to the presence of nearby masts and rigging, and due to the electrical noise of the adjacent city and vessels.  If you are able to connect to the SailMail station at all, your traffic will be transferred slowly due to the rotten signals, and your SailMail transmissions will interfere with other vessels in the marina as they monitor voice SSB weather and nets. 

If you are in a marina or harbor with  nearby vessels, and MUST use SailMail, be certain to avoid the times of the marine and ham cruisers' nets to avoid causing interference with them.  You can also dramatically reduce the interfering "splatter" caused by your SSB if you make sure that your batteries are FULLY charged when using SailMail, and if you reduce the transmit power of your SSB somewhat.    You will find that reducing your transmit power will have little effect on your transfer times; indeed many hams routinely run at 25 or 50 watts transmit power when using Pactor.  A reduction in transmit power, in conjunction with using fully charged batteries, will dramatically reduce the interference that you cause to  nearby vessels.

Do not sign up (via your SailMail address) to services that routinely send you email messages (stock quotes, Yotreps, weather).  If you sign up to one of these services, and then travel ashore for a while or are otherwise unable to download your messages, your SailMail account will become useless because there will be so many messages queued on the station for you that you will not be able to get to the messages that you are really interested in.  Similarly, do not sign up (via your SailMail address) to subscription news services or other "broadcast" internet email services.  There are other communications technologies that are better suited to receiving general news; for example get your news by listening to the BBC.  SailMail station time is best used for personal email communications for which there are few inexpensive alternatives for non-hams.

Promote the SailMail Association to potential new members.  If the membership in the Association grows sufficiently, the Association will be able to afford to set up additional stations and further improve the AirMail software.

Once again, LISTEN FIRST.  Before you transmit, be sure to listen carefully to be sure that there is no traffic in progress.  If there is already traffic on frequency, you will not be able to connect, your attempts may delay the traffic that is already underway, and your fellow members and cruisers will discover that you are a thoughtless heel.



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Frequently Asked Questions, Troubleshooting, Tips, and Trivia

NOTE:  There are hints, tips, explanations, and other useful information in the Help files that are integrated with the AirMail software.
NOTE:  There is very useful information in the Application Notes section of this Primer.


How can I save this SailMail Primer on my PC so that I can refer to it without accessing the SailMail website, which is obviously difficult when I am onboard my boat.
There is a link to a .pdf file at the top of this Primer.  The pdf file contains the entire SailMail website, including this Primer and the application notes.  Save the pdf file on your PC for reference.  Download a new copy from time to time when you have access to the internet.

How do I renew my membership in (or join) the SailMail Association?
There are lots of options.  You can fill out and "submit" the Application Form on this website,  print and fax it, print and mail it, or email the information.  Follow the instructions on the application form.  Basically we need your membership assessment (US$250 check, cash, or credit card information), your vessel name, your marine callsign, your normal (non-SailMail) internet email address, and your agreement to the SailMail terms and conditions. 

When your account is renewed, you will receive a confirming email to your internet email address, and to your SailMail address.  This often takes up to a week: sometimes shorter when things work out conveniently, and sometimes longer when the sysops are out of town on their day jobs, or sailing themselves (it is only fair).  Do not leave renewal until the last minute.  Even if you send your renewal early, your membership will be extended for one year from the time that it would have otherwise expired.

(send membership assessment and membership information to:)
SailMail Association
39270 Paseo Padre Pkwy, #850
Fremont, CA 94538

fax number 877 282 1485

Download and print new copies of the SailMail FCC Licenses to keep aboard. While you are at it, download a new copy of the .pdf of the SailMail website to keep onboard for reference.   It can't hurt to quickly review the SailMail Primer, particularly the Recommended Operating Practices and this FAQ section.

How do I contact the SailMail Association?
How do I get technical support by telephone
See the Contact Us page on this website.  There are email address, fax numbers, and phone numbers for both technical support and administrative (e.g. membership) questions.  

There is also terrific technical support for SailMail available worldwide.  Review the list (in the opening page of the sailmail.com website) of marine electronics dealers who sell and install modems that work with SailMail.  Any of them can help you sort out your installation (but again, be sure to pay them for their help).

RTFM (Read The "Fine" Manual).  Please carefully read this documentation completely before emailing questions to the sysop.  Pay particular attention to this "Frequently Asked Questions, Tips, and Trivia section."  Get help from the dealer from whom you bought your Pactor-modem, or any other marine electronics technician, and pay them for their time.   Finally, ask around among nearby cruisers for help.   You may find an experienced SailMail member or ham who can help.

Review the Help file in AirMail itself.  There is lots of good information there.

Wait until you have diligently read this SailMail Primer, looked through AirMail help, and until you are in good humor before calling technical support or emailing messages asking for help or advice to the sysops; remember, we do this to support fellow cruisers, and not for a living.  Be sure to include your radio callsign and vessel name in any email to the sysops.  Don't hesitate, however, to send us compliments or thanks if appropriate.

Iridium GO!   What is it?  Does SailMail support it?  Should I get one?  What are the advantages?

The GO! is a small Wi-Fi "hotspot" that provides voice telephone service via a Wi-Fi connected smart-phone, and data access to certified apps including SailMail with less expensive data rates. This expands SailMail's seamless service via radio, satellite and land-based internet to the Iridium GO!, with no setup required. The Iridium GO! is supported by the new Airmail 3.5 release, available at http://siriuscyber.net/sailmail/#iridiumgo  For more information see www.saildocs.com/IridiumGo  

The Iridium GO! is a terrific add-on to SailMail.  Using the Iridium GO!, as with any satellite, cellular, or other non SSB access, there are no connection time limits.

To see video of how to set up and use the Iridium GO!, and see it in action, see:

Can I run the AirMail software on Windows 7?  What about the 64 bit version of Windows 7?  What about Windows 8?  What about Windows 10?
Our recent software releases work fine with Windows 7, 8, and 10.  

Where people usually have problems  is with off-brand or no-name USB to serial adapters.   So if you use a USB to serial adapter, make sure there are drivers available for your operating system.

Also read the note below for suggestions on finding AirMail files in system folders.

How can I transfer my airmail inbox, outbox, saved, addressbook etc. files to Airmail on a new computer without losing the date stamps and order?
Just copy the folders from the old computer to new. Then restart Airmail and let it run for few minutes to update the message index. Each message folder has an index file (msglist.txt), Airmail scans that list and the files to update its index.  For WinXP, the various message folders all live in the "Airmail" folder, under Program Files.  For Win-7,8,10, programs and data are kept separately, so the various message folder live in a second "Airmail" folder under "ProgramData" instead of Program Files.

Note that Windows does not like to show the contents of system folders: From Windows Explorer (Start-button, All Programs, Accessories), select the "Tools" menu (press the "Alt" key on the keyboard if the menu's are hidden), then select "Folder Options". Click the "View" tab, and check "Show hidden files and folders", NO check for "Hide file extensions for known file types", NO check for "Hide protected operating system files" (and click "Yes" to the confirmation). This will show all files, and also show file-extensions.

There is one more file that you may want to copy, the address book file-- "addrbook.txt" which lives in the Airmail folder (the one under ProgramData, for Win-7,8,10).

Should I use a GAM antenna?
The GAM antenna is a pair of wires attached an uninsulated backstay with a plastic extrusion. It is long enough to serve as an antenna on its own, but by coupling it to the backstay then it couples to the backstay and the whole rigging system becomes part of the antenna (assuming no insulators). This can cause somewhat higher levels of RF inside your boat when you are transmitting, and so may require you to use more ferrite filters to keep the RF out of your laptop, pactor modem, and sensitive electronics such as your autopilot.

Should I use a KISS-SSB counterpoise (radio ground)?
The KISS is basically a single element used as a counterpoise, much like the opposite leg of a dipole. There will be some coupling to seawater depending on your installation and the location of the KISS, but some of the signal will be radiated inside the boat where it can subject your onboard electronics to RF.   This can increase the need for ferrites to keep the RF out of your laptop, pactor modem, and other sensitive electronics such as your autopilot.

Can I retrieve my SailMail messages via the Internet?
Can I retrieve my SailMail messages via Iridium (or Inmarsat, or KVH/VSAT, or Globalstar, Thuraya, or WiFi, or a Cellular Data Network)?

Yes.  In fact the efficient SailMail's protocol is highly optimized for low-bandwidth, high latency communications systems such as satellite (and SSB-Pactor radio) communications so you will find that using SailMail over your satellite system saves you tons of satellite time and money.  It's easy. 

First, make sure that your computer has access to the internet.  One quick way of testing that your internet access is working is to open www.google.com in your browser.  Once you are certain that you have access to the internet, in the Message Index Window click the "Internet" button, which looks like a lightning bolt.  Then click the "connect" button, which looks like a green ball.  You system will send and receive any messages just as if you were connected via radio. 

If you use Iridium for accessing the internet, consider using the Iridium PPP Data Service instead of the Iridium "Direct Internet Service."  This is a direct-to-internet connection through the Iridium internet gateway in Phoenix that is simple and provides very fast setup, which minimizes your Iridium connection time.  You can even set up AirMail to make the connection via your Iridium phone, transfer your messages, and then disconnect.  You will be amazed how quickly and efficiently this works and how little Iridium time is required given the compression and efficient protocol of the Sailmail system.

For details on how to set up your computer and AirMail installation to use the Iridium PPP Data Service, see the notes at:  www.saildocs.com/sailmail/iridiumPPP.txt   You can also request an email containing this document to be sent to you by sending a blank email to iridiumPPP@saildocs.com

Does the Inmarsat iSatphone work with SailMail?
The iSatphone works well and is less expensive than the Iridium phone for example, and the per-minute charge is cheaper (depending on usage and plan). But data speeds are slower and connection time is longer. So the overall costs are probably a wash, depending on individual usage.  Our setup instructions for the iSatphone are available on the web at www.saildocs.com/sailmail/isatphone  or send a blank email to: isatphone@saildocs.com

I understand that if I use Inmarsat (iSatphone or FBB), the Inmarsat unit provides a unrestricted connection to the Internet.  How can I make sure that various programs on my PC don't start using expensive Inmarsat communications to do routine updates?
Install AirMail version 3.5.025 or later.  There is a new feature to establish a "dedicated route" which is ideal for the Isatphone, FBB, or any unrestricted access to the internet that you are paying for. This restricts the internet connection to Sailmail and eliminates the need to make any changes to the Windows firewall.

Open Airmail's internet window, both servers (now called "Server1" and "Backup1") are configured with numeric IP addresses (to save the time of looking up the internet address via the phone connection).

Check the box for "First connect to" and select either server. Then, just below that setting, check the box for "Set up dedicated route to server". You may see a confirmation message from Windows, this is normal when making system changes.

Now click the green button to establish the connection. You will see one additional line, "Setting up dedicated route". This limits the use of the internet connection to only the Sailmail server, other programs are blocked. Once the connection is close then this dedicated route is reset to the normal state.

Which handheld Sat Phone do you recommend, Iridium GO!, an Iridium phone, or Inmarsat Isatphone? Where should I buy my data plan?

The Iridium GO!  has the cheapest data plans.  Plans vary so be sure to shop around.  Among other vendors, check the prices at www.OutfitterSatellite.com    Both Iridium units and Inmarsat isatphone have strengths and weaknesses. Iridium's satellites are in low-earth orbit (LEO's) and are relatively close, meaning strong signals and an easier connection from you to the satellite. Being in low orbit they move quickly relative to the earth and sometimes data calls are dropped.  Inmarsat uses geostationary satellites (GEO's), which will always be in the same location in the sky, but are much farther away which means weaker signals and slower speeds but fewer dropped data calls.

In either case, a proper external marine antenna is important, located where it has a clear view of as much sky as possible.

There are three choices for Iridium products, the GO!, the 9555 and the 9575 "Extreme" ruggedized phone.   The GO! has the cheapest data plans but is fiddly to use for actual phone calls.  The Iridium 9575 Extreme would probably be handier if you had an emergency.  The Extreme can be used by itself to make phone calls, is water resistant, and contains a GPS and GEOS emergency button.  So if your Extreme is registered with GEOS (free), you can press the red button on the Extreme, and folks on your registration list, as well as SAR authorities, will be forwarded your location and your request for help.  And in the event that you press that red button, the SAR authorities will likely call you on that phone to ask for details and confirmation of your problems.

Most folks go with Iridium over Inmarsat.

Can I use my iPAD or iPhone with SailMail?
Yes.  For details see the document www.saildocs.com/sailmail/iPAD  or send an email to iPAD@saildocs.com 

I only use Iridium to access the SailMail system.  I want to continue to use the SailMail servers in order to take advantage of SailMail's compression, spam filtering, virus filtering, and Shadowmail system.  Because I don't use SailMail's HF radio network can I get a cheaper membership?
The cost is $250 per year, whether you use the SailMail system via radio or Iridium.  Most other email gateways for the Iridium phones charge monthly and the minimum is usually $30 per month. SailMail charges annually in order to keep the costs down. The $250 breaks down to about $20 per month, which turns out to make SailMail the least expensive email gateway for Iridium email.

I've got an Iridium and am looking for an email provider.  There seem to be lots of alternatives out there.  Why is Sailmail the one to use?
Iridium provides a direct internet connection from your PC to internet. In theory you could use this with nothing else to access your email (e.g. your gmail account), browse the web, etc -- the problem being that Iridium is glacially slow and the data is expensive (2400 bps which ends up costing $60 or so per Megabyte).  What is needed is an efficient way to access email and get weather info, and this requires a specialized "gateway" service which not only uses compression but also uses communications protocols which are optimized for slow connections and long link-turnarounds. This is what Sailmail provides: A separate mailbox, efficient mail-forwarding protocols, specialized weather tools, and a method of checking other email accounts. Membership is $250/yr, no additional costs (except for Iridium airtime), and no limit on usage via internet.  As a bonus, if you have a SSB and a pactor modem you can use SailMail's network of radio stations to save on your Iridium costs or as a backup.  There are no additional airtime costs to use SailMail's radio stations.

We will be sailing from X to Y.  Will SailMail provide adequate coverage?
The short answer is yes.  SailMail has stations scattered around the world.  Members with good radio installations and who are reasonably clever at picking times, stations, and frequencies have used SailMail from everywhere in the world that you can take a boat.     The longer answer follows:

Each SailMail station is easily used at ranges out to 4000 miles, and is useful at ranges out to 8000 or more if you have a good radio, tuner, and ground installation, and if there are no nearby sources of interference.  It also helps if you are reasonably skilled at choosing the best station, time, and frequency.  You will find that your speed of data transfer slows as you get farther from a station, although if you are clever at picking times and frequencies you can still get fast data rates at long distances.  Ham's are expert at this.

You may find it helpful to download, install, and use the propagation program for Airmail from the download page on the SailMail website. But remember that it is only a computer projection, so use it as a guide but not as the "bible".   As you sail around the world and your location relative to SailMail stations slowly changes, you will get pretty knowledgeable about picking times, stations, and frequencies.  Comparing notes to other SailMail users that you run across will also help you pick times, stations, and frequencies.

Can I use the ham "WINMOR" protocol?
No.  WINMOR doesn't make efficient use of limited station resources, and we're also concerned about the level of support needed -- Sailmail members are generally not as savvy as hams on technical issues.

I hear periodic "rasping" sounds on SailMail frequencies.  What is it?
Pactor-II sounds like periodic chirping.  Pactor-III sounds like periodic "rasping."  As always, listen and make sure that a SailMail frequency is not in use before you connect.  If you hear either chirping or rasping, do not attempt to connect.

How can I receive weatherfax images with my SCS Pactor modem?
Weather charts are created by NOAA and broadcast via radiofax by USCG, and can be received with Airmail software using any of the SCS Pactor modems.

The first thing you need is the broadcast schedule. So go to this web page:  http://weather.noaa.gov/fax/marine.shtml  Scroll down and find "Worldwide Marine Radiofacsimile Broadcast Schedules (PDF)" and download a copy. There are five US broadcast stations: Pt. Reyes (near San Francisco), New Oreans, Boston, Alaska and Hawaii, plus a bunch of overseas stations. The US stations are coast guard and quite reliable, the others vary.   The schedule tells you times for each chart, for each station.

Now open Airmail, open the "fax" window ("Get Fax" under Modules menu, or button on toolbar). With radio and modem powered on, select fax mode, select station and frequency. The radio freq should be set (selected freq minus 1.9 khz), and you should hear a characteristic "warbling" fax tone, if the station is transmitting. Try each frequency for the clearest signal. Then wait-- Airmail will detect the special tone at the beginning and end of each fax transmission, copes each chart and saves them automatically.

You will note in the schedule that the charts are send in blocks over a couple of hour period, just turn the radio on and open's airmail's fax window, and let it run during that period.

Now, all that said, you can get most of the same information from GFS grib data. The zero-hour forecast-time is based on actual conditions, then each forecast is computed from that. The same data is used for grib files, and also to generate the fax charts. The fax charts are reviewed by forecasters, and information added-- storm warnings, frontal positions, etc.

Is it possible to receive NWS weatherfax charts images via emails via SailMail?
Is it possible to receive a NWS weathermap image that I request via FTP mail, via SailMail?
No, those are best received via broadcast weatherfax as described above.  Note that when you receive weatherfaxes as described above, you don't use any of your SailMail connect time.  SailMail doesn't forward image files because the size is generally too large for radio email.  An alternative is to request grib files, these are computer weather-data files that start with the analysis (zero-hour forecast) and go out as far as you want. The advantages are that you can get as much detail as you want, and the file sizes are pretty small for the amount of data that you get.

Can I get text weather forecasts sent to me via SailMail?
ou can arrange to have text weather forecasts emailed to you via SailMail via the automated email services www.SailDocs.com (free).  For information send an email to info@saildocs.com or go to the SailDocs.com or BuoyWeather.com websites when you have access to the internet.  It is also possible to request text forecasts directly from the NWS, but the NWS server is somewhat more cryptic to use.  For information send an email to ftpmail@ftpmail.nws.noaa.gov  and in the first and only line of the message put "help".  PredictWind offers a service in which they can send you text routes for your boat.  See  http://www.predictwind.com for more information.

Can I get news bulletins sent to me via SailMail?
The best option, in our view, is to fire up the SSB radio and find BBC world Service or Voice of America on the shortwave bands. 

I keep hearing about "grib" files.  What the heck are they?
an I receive grib files of digital weather data over SailMail?
Are grib files free or do I have to pay for them?
Grib files are data files containing weather information, usually surface wind and surface pressure, on a (typically) 1 or 2 degree grid.  The name comes from "GRided Binary."  The SailMail system can pass grib files, but only if they are less than 30kBytes in length if sent via Pactor-III or less than 40kBytes via Pactor-4  (10kBytes via Pactor-II).  Grib files need to have the ".grb" file extension.    We have found that if you wisely pick your area coverage, time coverage, and spatial resolution, a 10 kByte grib file contains plenty of data to plan a trip, even crossing an ocean.

NOAA's Global Forecast System (GFS) is widely regarded as the best worldwide computer weather forecast.  US taxpayers pay to run the GFS and NOAA graciously makes the results free to everyone.    The SailMail Association supports a system called SailDocs that formats Grib files containing NOAA GFS data for efficient transfer to mariners.  The SailDocs system is available to everyone via any email system at no charge.   This is sensible, given that the US taxpayers have already paid to run the GFS, so why should they be asked to pay yet again?  For information on how to use SailDocs send an email to info@saildocs.com   For specific information on the weather models and on how to get grib files sent to you via SailDocs, send an email to gribinfo@saildocs.com   and to gribmodels@saildocs.com  The AirMail software contains a handy tool to subscribe to grib files under that can be found on the main AirMail Message Index window under Window/Catalogs/Saildocs/Grib Files.

There are various software packages that are used by computer-savvy cruisers and racers that display grib files of weather data.  Some also display digital charts, and some can even calculate routes.  The easiest grib viewer to use, and cheapest (free) is Jim Corenman's AirMail Weather Fax Companion that is included in recent downloads of the AirMail program.  Other programs that can view grib files include Deckman for Windows, Expedition, MaxSea, Adrena, and Ocens

I receive both weatherfax charts, and grib files.  How do they compare? 
If you compare weatherfax charts and grib files from the same model-run, and for the same forecast time you will find that the isobars are nearly always identical.  For example
request a GFS grib file for the 00z synoptic time (e.g. request it for 0500 utc), then get the 48h surface prog fax chart for the same synoptic time (available by 0800-1000 utc), pull up the 48h grib forecast and compare to the fax chart, as a validation of the grib data.  What you will find is that 99% of the time the isobars match exactly.  Meteorologists will occasionally advance or delay the forecast from the GFS data, or make some changes, but that is rare-- offshore there is very little actual data for comparison.   Of course the weather fax charts will also show fronts, which are not shown on the grib files.  OTOH if you request and display rain on your grib files, that will do a good job of showing the frontal locations.

I've joined SailMail, but won't actually be departing on our cruise/race for some time.  Is it possible to practice with text and grib requests for weather data from our home computer?
Yes. The simplest way to do this is to do is to install Airmail software on your home computer. Do the setup the same way (the modem and radio settings don't matter of course), and then make one additional change: open Tools/Options window, settings tab, and change the "current message number" for the home computer to 10000 (from 1000), that will avoid any possible duplicate message-numbers. (Sailmail tracks messages with this number).   Then, instead of using the radio and Airmail's terminal window, open the "internet" window (lightning-bolt button on right side of the toolbar). This connects to Sailmail the same way that the radio does, except via internet and much faster of course. You can send/receive messages via your Sailmail address, request weather, everything.

Can I receive ".gfcst" or ".fcst" files from MovingWeather?

Several companies sell for-fee subscription services that can email grib files or other weather files.  Note, however, that grib files have to be attached to an email, they have to have the ".grb" or ".grib" file extension, and they have to be less than 30kBytes in length in order to be sent via SailMail via Pactor-III, 40kBytes via Pactor-4 (or 15kBytes in length if sent via Pactor-II). 

MovingWeather provides weather data in either ".fcst" or in a compressed ".gfcst" format.  The SailMail system will pass ".fcst" files that are less than 10kBytes in length via Pactor-II or 30kBytes in length via Pactor-III or Pactor-4.  Because the ".gfcst" files are pre-compressed they SailMail system can only pass ".gfcst" files that are 5kBytes in length via Pactor-II or 15kBytes in length via Pactor-III or Pactor-4.

How can I arrange to receive custom weather forecasts via SailMail?
There are a number of meteorologists that are in the business of providing custom weather forecasts for cruisers (and especially wealthy racers).  These services are particularly helpful for determining when to leave on a passage.  These meteorologists are also willing to send you periodic emails during your passage with custom routing advice and forecasts.  Generally these services cost from $75 to $300 per passage, depending on whether you want continuing help during your passage and how often.   All of the services below are familiar with sending advice via SailMail.   We highly recommend the use of a consulting meteorologist, particularly for new cruisers who have not yet become confident in their ability to interpret weather data.  If other consultants would like to be listed please send your contact information to sysop@sailmail.com  

Commanders' Weather MA USA, 603-882-6789,   info@commandersweather.com, www.commandersweather.com
Rick Shema, WeatherGuy.com HI USA, 808-291-9949, hawaii@weatherguy.com, www.weatherguy.com
Chris Bedford, Sailing Weather Services MA USA, 617-926-7457, sailwx@mediaone.net, www.sailwx.com
Bob McDavitt, Weather Ambassador for METSERVICE New Zealand, 649 377 4831, mcdavitt@metservice.com
Chris Tibbs, Sailing-Weather UK, info@sailing-weather.com, www.sailing-weather.com
Weather Consultancy Services Ltd UK, 01902 895252, office@weatherweb.net, www.wcsmarine.com
Weather Routing, Inc (WRI) - New York, USA (518) 798-1110 www.wriwx.com
Ken McKinley, Locus Weather,  207-236-3935, locuswx@midcoast.com, www.locusweather.com

PredictWind offers a service in which they can send you text routes for your boat for a fee.  See  http://www.predictwind.com for more information.

If you are in a race, be careful not to infringe RRS 41 by paying for weather data.  Gribs from Saildocs are ok to use because they are free and available to everybody.  There are other free sources as well.

How can I learn more about weather?
Take courses, read books, and watch the weather maps and sky every day even when ashore.   Practice.

Lee Chesneau, whose name experienced cruisers will recognize from thousands of OPC weathermaps, has retired from OPC and now does a terrific job of teaching meteorology to sailors.  Lee's courses are listed on his website at www.ChesneauMarineWeather.com    Various community colleges also have courses on meteorology.

Meteorology Today by C. Donald Aherns is a good overall textbook on meteorology.  Weather at Sea by David Houghton is a good book on marine forecasting.  All of Alan Watts' books are  worth reading.  For racers, don't miss Bernot on Breezes by Jean-Yves Bernot.  Eric Brenstrum of the New Zealand Met Office has written a very good book titled, The New Zealand Weather Book, that is useful nearly anywhere, but is particularly good for the South Pacific.  Steve Dashew has written a book that provides a good overview on weather titled, Mariner's Weather Handbook.

Could you please tell me how to read wind velocity from the feathers of the wind arrows in a Grib file chart?
How can I find the fronts on a grib chart on which I can only see wind directions and pressure?

The wind arrows on a weathermap fly with the wind.  There is
10 knots for each large "feather" plus 5 knots for each small feather. So 3 full feathers is 30 knots, rounded. The wind-speed in knots is also shown in the status-bar as you move the cursor over the chart if you use viewfax.exe to look at your grib files.   You can work out where the fronts are by looking at the wind directions and the kinks in the isobars.   The feathers are always drawn on the low-pressure side of the arrow.  To learn more about weathermap interpretation and grib file interpretation see the question above about learning about weather.

I want to use the Grib files that I get from Saildocs with my new routing software (e.g. Expedition, DfW, or whatever).  The software needs to know where it can find the gribfiles which have been downloaded with Airmail. Whatever I try, I cannot find them.
One easy solution is to open the AirMail message that contains the grib file, right click on the symbol for the grib attachment that is shown at the bottom of the message, and then save it to a folder on your desktop or wherever, that you will subsequently open with your routing or chart display program.  This will  give you allow you to access and view your grib files even after you close AirMail.

I sent a request for a grib file to SailDocs and the file that was returned was 6 hours old.  Why is that?
The GFS model is run every 6 hours, with data taken at at 00, 06, 12, 18 Z (UTC).  The convention is to identify each run with the time at which the data was taken.  It takes about 5.5 hours to compute each run.  So the "0Z" GFS model run will be the one that uses observations taken at 0Z, and is available at about 6Z.  So if you request a grib file at 12Z or later, then you will get the 06Z model-run. The 06Z is the "synoptic time", i.e. the forecasts are based on observations taken as of 0600Z, that is also the "zero-hour" valid-time for the grib file.  By the time you get a grib file, it will always be at least 6 hours old.

A good practice is to enter a subscription for every 12 hours, time 00Z, then plan to connect around 06Z and 18Z to pick them up.  If you don't pick up one of your grib files until after another gets sent to you, AND if you requested the files as a subscription, then Sailmail will delete the older grib files so they do not pile up.

All weather forecast times that are displayed in Viewfax are in UTC, which is the standard for weather forecasts.

Some beginning cruisers initially complain that it is confusing that weather is always described in GMT, or Zulu time, but as sailors become more experienced they nearly always come around to concluding that it makes sense and is actually the simplest and clearest way of keeping track of which forecast is which.

I can connect to the SailMail stations and get the "Welcome..." message and then the callsigns, but then it disconnects right away.  What's wrong?
Nothing.  You don't have any messages queued for you.

Are there limits on SailMail usage?
I received a warning that I am using SailMail too much, what is happening?
The station refused my connection and said that I have been using SailMail too much.   What should I do?
Unfortunately there have been a few members who have abused SailMail and have used far more than the recommended guideline of 90 minutes per week, forcing us to put in usage limits.  If your average usage over the last seven days is too high, you will notice a warning message when you connect with SailMail.  If your usage stays too high, SailMail will periodically refuse to connect with you to limit your usage.

Obviously, it is inconvenient to have the station refuse your connection, particularly if you are trying to send or receive an important email.  If you receive a warning message, you should  reduce your usage to avoid having a connection refused.   If you are using an SCS Pactor-II modem without a Pactor III license, upgrade to the Pactor-III protocol which will give you about 3-4 times more email capability in the same station time as your non-upgraded Pactor-II modem.  If you are already using Pactor-III, then be more careful about when you connect to the station.  You might also consider upgrading to Pactor-4 which will somewhat increase your email capability in good conditions.   Only connect to the station when radio propagation is good, and don't stay connected if your traffic is moving very slowly (press the stop sign in the Terminal Window to disconnect, and leave any partial messages in your Message Index alone).  Try again later when propagation is better for you.   Finally, you may have to send and receive fewer emails. 

As members cruise farther away from the SailMail stations, they will experience slower transfer rates, and will have to reduce the number of messages that they transfer in order to stay under 90 minutes per week of station usage.

I paid 250 bucks to join this outfit and now I find out that I am limited to 90 minutes per week, why is that?
The SailMail Association struggles with a problem widely known to economists as "The Tragedy of the Commons."  If there is a shared resource (like a common pasture) each farmer has the incentive to add to his/her herd and use more of the shared resource.  Ultimately the common pasture is ruined by overgrazing.  SailMail is a cooperative Association of cruisers that has set up a shared resource, the network of SailMail stations.  We have ended up implementing connect-time limits to fairly allocate our shared resource, and to avoid "The Tragedy of the Commons."

The terms of our FCC licenses as a non-profit cooperative prevent us from implementing a pay-by-the-minute fee, which would be a reasonable economic solution for allocating the shared resource. If you need unlimited message capability, you should consider Iridium, Inmarsat, or KVH/VSAT, which are for-profit email services that charge by the minute or byte and therefore are happy to have no limits on usage. The KVH FBB150 is a relatively small, light, Inmarsat-based satellite dom with data costs of $13 per MegaByte of data transferred.   The KVH V3 VSAT unit is a somewhat larger satellite dome with data costs of just $1 per megabyte.   Iridium is the smallest and cheapest satellite hardware to buy, but pre-compressed data costs about $60 per Megabyte to transfer.

We measure and limit station connect-time, and not messages transferred, because it is the station connect-time that is our scarce resource.  By measuring and limiting station connect-time, members have the incentive to connect to stations at times and frequencies when propagation is good and their messages can transfer quickly, and to disconnect if they have a connection that is hammering away for minutes and transferring messages very slowly.

I joined SailMail primarily to use the system for the two week period of the ARC (Transpac, Pacific Cup, etc...).  Because I will primarily be using the system for the two weeks of that event and little over the rest of the year, why can't I use my entire 4680 minutes of connect time (52 weeks times 90 minutes per week) during those two weeks?
Exchanging email via SSB radio is not fast, especially at longer distances, and capacity is limited-- this is the nature of HF radio.  The SailMail Association sizes its stations around the world to be able to handle the peak loads that occur during the prime cruising seasons in each region, and during events like the ARC, Pacific Cup, etc.  The equipment necessary to handle these peak loads is what determines the cost to run the SailMail Association.  We can't buy and sell radios and have more stations and radios running just during the peak season.   Similarly we can't magically move idle station hours during the off season to the peak season.  The weekly time limit is necessary to make sure that station capacity is shared by all members, even during peak times.  SailMail's Terms and Conditions are very clear on this, "90 minutes per week."

Sailmail provides unlimited use via satellite connections. Many Sailmail members also use Iridium or Inmarsat in addition to radio when it is necessary to send/receive more traffic and cost is less important.

If I have a crisis like a family emergency or medical emergency and need more access to the SailMail system during that emergency, can I use SailMail more than normally permitted?
Of course.  But for us to allocate you more station connect-time, you must send an email to the sysop telling us of the crisis BEFORE you run out of connect-time and have your connections refused by the stations.  We are not clairvoyant.  Note that crossing an ocean is not an emergency; that is what all SailMail members routinely do.

We are about to sail across an entire ocean, all by ourselves, and so need unlimited SailMail time.
Our waterpump failed and so we need unlimited SailMail time to order a new one.
We have a teenager onboard and so need unlimited SailMail time.

If you have a true emergency and need more SailMail time during that emergency, let us know and we will allocate you more SailMail time.  Getting weather data during passages and ordering replacements for broken gear is normal usage; we have thousands of members using SailMail for similar purposes.  If you need more message capacity, be sure that you're upgraded to use Pactor-III mode or consider a P4dragon, and use the propagation tool to pick the best times, stations, and frequencies.   If you need still more time consider buying an Inmarsat, Iridium, or KVH/VSAT system to use to connect to the SailMail system.  SailMail works great over satellite and SailMail has no usage limits for traffic that does not use our SSB stations.  Satellite providers charge by the kilobyte or by the minute, and so they are delighted to not have any usage limits.

I know we can't receive essentially anything except gribs as attachments, but can we send small jpeg or other files back home?
You can send any type/size of file either over SSB or satphone via SailMail.  When sending you are in control, so there are no limitations on sent attachments other than you should keep an eye on your connect time if you are using SSB.

Using the Satphone exclusively, are we still limited to the 90min/wk running average?
There is no “time”  limits on connecting via internet or satphone. You are only limited by your checkbook in paying for the satellite airtime.

I've been away from my boat for a while and probably have lots of messages backed up.  What should I do?
I've been away from my boat for a while, should I download the latest version of AirMail
I haven't used SailMail for a while, how do I find out about new stations?
If your PC can be connected to the internet via WiFi or any other means then use AirMail and download all of your SailMail messages via the internet.  To get details on how to do this send an email to internet@saildocs.com or look at an application note at www.saildocs.com/internet 

If you cannot connect your own computer to the internet then stop by an internet cafe, and download AND DELETE all of your messages there using Webmail.  That way you will not have to use your connect time to retrieve them by radio.

It makes sense to download and install the latest version of AirMail.  The new installation will preserve your old messages and settings, and will include the latest information about SailMail's stations.  While you are at it, download a new copy of the pdf file for this Primer and keep it handy as well.  The link to download the pdf is near the top of this Primer.

Does the number of addresses to which a message is addressed appreciably change the transmit time?
How can I send copies of my newsletter email to multiple email addresses without every addressee seeing everybody else's email address?

A long cc list does not appreciably increase the transmit time.   Note however that some internet service providers reject messages with long cc lists as likely spam.   There is an alternative way to send out multiple emails: Sailmail's "relay" feature.  Using SailMail's "relay" feature avoids the potential problem of your message being rejected as spam and also lets your addressee's live under the (incorrect) impression that you are writing only to them.

SailMail's relay feature allows you to send one email to a special address, along with a list of email addresses, and the server then sends an individual note to each recipient. You can even personalize each note with "Dear Mom" or whatever, if you want. In this case the list of recipients does NOT go in the cc-box, instead it is included at the beginning of the message. This is all explained in a special "how-to" note, send a (blank) email to: relayinfo@saildocs.com 

I was disconnected during the reception of a message. What should I do?
In general, if you are disconnected or see an error, then try to reconnect to the same station immediately.  If you think you can do better by connecting to the same station at some other time or on some other frequency, then try that.  If a different station would be better, then go ahead and connect to the different station, but if an error occurs then reconnect a second time to that same (new) station; it should work fine then. 

The feature of resuming a partial transfer only works on re-connections to the same station, otherwise you will see the CRC error because the two halves of the file don't match.  If you connect to a second station, you will get the message, but sometimes only on your second connection.

Can I access my SailMail messages from the Internet?
Yes.  The easiest way is as follows...

If you can get internet access to your computer via WiFi or by taking it ashore then open AirMail and in the Message Index Window, click the "Internet" button, which looks like a lightning bolt.  Then click the "connect" button, which looks like a green ball.  You system will send and receive any messages just as if you were connected via radio via a very fast connection.  

The enormous advantage of this approach is that all of your messages end up in the AirMail folders just as if you had picked them up via radio.

If, instead, you have to read your messages via a public computer at an internet cafe then browse to the SailMail website at sailmail.com, select the Webmail page, pick a service, and then enter your username and SailMail Password and you can directly access your email.  Your username and SailMail Password were sent to you in the "Welcome" message that you received when you first joined SailMail.

Note that if you delete an email via Webmail, it will no longer be retrievable by radio.  Similarly, if you pick up a message via radio, it will not appear via Webmail.

Note that this is exactly the same procedure that is used to access your SailMail messages if you have an Inmarsat or Iridium terminal, and so have access to the Internet via satellite.

Does SailMail have normal POP3 and SMTP servers so that I can retrieve my SailMail messages using Outlook or using my existing PopMail account?
Yes.  SailMail's POP3 and SMTP servers allow you to retrieve your SailMail messages either via a normal internet email program (e.g. Outlook, Outlook Express, Eudora, Netscape Communicator) or via an existing webmail account that you might have that provides the ability to retrieve from other POP3 servers, e.g. www.yahoo.com     To use SailMail's POP3 and SMTP servers you will need to use your username and SailMail Password that were included in your "Welcome Message" that was sent when you joined the SailMail Association.   You can get instructions on POP3 by sending an email to POP3@saildocs.comIf you haven't set up POP3 email readers before, or if you found any part of this paragraph to be unclear, then you should find a teenager and ask for help.  Better yet, just retrieve your SailMail messages using the AirMail program as described in the question above.  If you set up an email program to retrieve your SailMail messages via SailMail's POP3 server, be sure to set up your email program to NOT leave the messages on the POP3 server.  If you leave the messages on the server then they will all still be there when you get to your boat and you will have to waste SailMail station time to download them yet again.

I have retrieved my messages via the Internet, but when I return to my boat the SailMail system tries to send me the same messages.  Why is it sending me messages that I already retrieved via the Internet?
Be sure to read the instructions on the WebMail introduction pageIf you leave messages on the web mail servers, they will remain queued for sending via radio.
Be aware that when you retrieve and delete your messages via Webmail, it will take up to an hour for those messages to be removed from all of the SailMail stations.
If you are using your own email program, then change the options to NOT leave the mail on the server. When you leave messages on our POP3 server, they will remain queued for sending via radio.

I have my SailMail Password that was sent to me as part of my welcome message, but I want to change it.  How do I do that?
Send an email to sysop@sailmail.com  with the new SailMail Password that you want to use.

How long will my messages stay on the SailMail system if I don't pick them up?
Messages will remain on the SailMail system for 30 days from the day they are received.  There are a few exceptions.  Messages from the sysop remain for 90 days, and weather related messages like weather reports from the SailDocs system have their own expiry dates and generally expire within a week or so.

I sometimes connect to the SailMail system using my Iridium handset.  If I get disconnected before I've retrieved all of my messages, when I reconnect, the SailMail system says that there are no messages for me.  How do I pick up the messages that have gone missing?
When the Iridium stops, it is because the satellites have moved, and lost the connection. You see "no traffic" when you reconnect because the first connection is still open at the Sailmail server, and the messages are in the process of being sent via the original connection. Once that connection times out then the messages will be again available for sending, because they were not delivered and confirmed. But this takes a few minutes.  If you wait 10-15 minutes before you reconnect, then the problem will not appear. Also, that will give the satellites a chance to move a bit and the connection might be better. If you try again quickly then you often get the same lousy connection.

I am receiving SPAM (unwanted email).  Is there anything I can do to avoid it?
Spam results from the fact that you or one of your correspondents included your SailMail address on a website, a news-group posting, or on a widely forwarded email such as a joke or chain-email.  Another possibility is that one of your correspondents might have his/her computer infected with a virus that is sending the contents of his/her contacts folder to a spammer.  Additionally many businesses sell their customer's email addresses onto the spam lists. 

Do not use your SailMail address when you fill in a form, order something, or correspond with a business.  The best approach is to maintain another email account such as a www.yahoo.com or www.hotmail.com account, and always use that address if you have to put an email address on any form or on the web.  It is much easier to deal with spam on your normal email account than it is to deal with spam on your SailMail account.

There were never ANY email messages sent to your SailMail address prior to when you started to use it.   If you and your correspondents keep your SailMail email address a secret, you will never receive any spam.  If you DO receive unwanted messages, it is because you or one of your correspondents (probably unintentionally) released your SailMail address on to the spam lists.  The SailMail Association NEVER releases any SailMail addresses to anyone (except to Search and Rescue Authorities in emergencies).  In fact if we receive inquiries about a member's email address we only forward the inquiry to the member.

If you start to receive SPAM, we can change your SailMail email address by a adding suffix to your registered callsign.  For example WXY1234@sailmail.com would become WXY1234A@sailmail.com. This will cause all email sent to your old SailMail address to get bounced back to the sender.  If you ask us to change your SailMail address in this way, you will need to make the corresponding change in your AirMail program, under Tools/Options/Settings/SailMail, and you will need to inform all of your (desirable) correspondents about your new SailMail address.  

Unfortunately, if your SailMail address does end up on the spam lists, the spam will never stop, and sending "remove" messages will just make it worse because you are confirming to the spammers that you are reading their spam.  Your only solution is to change your SailMail address as described above, and then be more careful about how widely you distribute your new SailMail email address

NEVER let  your SailMail email address be posted on a website.  If it does get posted, you will be on the spam lists within a few days and your only solution will be to change your SailMail email address as described above.  Occasionally we will get an email from a SaiMail member complaining that they kept their SailMail address secret, but are starting to receive SPAM.   Typically, if we search for that SailMail member's SailMail email address via Google, we find that their SailMail address is posted on some yacht club or cruiser's website.

Do not try to avoid spam by using the "defer-limits" in AirMail.  It will just make things worse; see the "Frequently Asked Question" on Defer Limits.

NOTE:  If you have an PTC-II or a pre-2002 PTC-IIe modem that does NOT have an electronic serial number (i.e. does not have a bar code on its label) but that has been licensed to use Pactor-III, changing your callsign will cause your modem to stop working in Pactor-III mode.  Before you change your callsign, send an email to Martin at SCS ( DL1ZAM@scs-ptc.com) to get a new license-code that will enable your modem to work in Pactor-III mode with either your current callsign or your new callsign and install this license-code BEFORE you ask SailMail to change your registered callsign.  Alternately you could wisely send your modem to a dealer to get it upgraded to have an electronic serial number ($100 or so).  If you do that, your modem will be able to use Pactor-III with any callsign, and it will be more valuable if you ever sell it.

Somebody is sending me email that I don't want.  Is there any way to "block" email from that sender.
See the above question and answer.  The only way to avoid unwanted email or spam is to not give out your SailMail address to unwanted correspondents.  Once an unwanted correspondent has your SailMail address,  the only way to stop the unwanted email is to change your SailMail address as described above.  You should then be more careful in the future when giving out your SailMail address.

Some ISP's use "Anti-Spam" services and refuse any email from any address on the anti-spam lists.  Why doesn't SailMail do this?
In our experience these services are almost totally ineffective, because only the most naive spammers use the same from-address (or the same SMTP server) more than once. The other side of the problem is that a lot of legitimate SMTP servers get on those lists by accident, or because of open-relay problem long since fixed, and legitimate email doesn't get through. This causes all sorts of hassles and administrative problems, and many ISP's who used to use such lists have stopped because the problems far outweighed the benefit.   The better answer is to simply not allow your SailMail email address to get on the spam lists in the first place.  I.e. don't let your SailMail address appear anywhere on the internet, and don't use your SailMail email address as a "return" address with untrustworthy businesses.

Can I manually reject an incoming message while it is being received AND force the SailMail servers to delete the message so I won't receive it in the future?
There is a basic difference in philosophy here: We designed the system to robustly deliver every message exactly once. There are a lot of checks to make sure that mail gets delivered, whether you lose the link in mid-message, whether there is a internet problem between the station and the server, whether the server goes down,  the station goes down, etc.  In all those cases the system will still get one copy of the message to you. Part of that robustness means that it is not easy to kill an unwanted message, but we don't believe that there should be any unwanted messages. Why would you give your SailMail address to someone and then not want their mail? They might make a mistake and send you a copy of their 500K dissertation, but that gets chopped at 35K and you know who it is from so that you can gently remind them to not send large messages in the future. The whole system is built on the premise that mail addressed to you should be delivered to you.  Your SailMail address is virgin when you get it, you are in control of that address, and who you choose to get mail from is entirely up to you.

You might consider only giving your SailMail email address to your closest and most trusted family and friends, and use the Shadowmail service to check your normal land based email account.  That way you can review the from addresses, subject lines, and lengths of all of the messages sent to your land email address and request that just the most important ones be sent along to you via SailMail.

You guys at SailMail once stated that you would develop an method of pre-viewing email so that I could only download the messages that I want.  What is the status on that?
We created a service called "shadowmail". Basically what it does is "peek" into a separate POP3 mail account that you specify, grab the headers (but not the message) and forward that to you via Sailmail. The Airmail software then maintains a "shadow" folder of your POP3 mailbox, showing from/to/subject and size. You can retrieve any message, delete it, send it elsewhere, or ignore it until later when you are ashore and can handle your email with a normal internet connection.  For more info see www.saildocs.com/shadowinfo    Generally, outgoing messages are sent with your sailmail.com from-address but you can override this for any message, and replies to messages received through Shadowmail are sent with that account's address.  Not using your SailMail return address is important in order to keep your SailMail address from being widely used.  All messages that are sent directly to your SailMail account will continue to be delivered as always.

When friends email me is my email address "case-sensitive", e.g. does it matter whether they enter my SailMail email address with capital letters or small letters?
As far as the internet and SailMail are concerned, the "case" doesn't matter; email will reach you no-matter whether your correspondents enter your SailMail email address with capital or small letters, and no matter which case you used to enter your callsign into AirMail's Tools/Options/Settings.

When YOU send an email, however, your return address will appear with the case of letters that you entered into AirMail when you set it up.  Therefore, in AirMail, under Tools/Options/Settings, carefully select the "case" for the letters in your callsign so that your correspondents will be least likely to confuse the letters with numerals.  For example if your callsign contains the letter "i" use lower case.  If your callsign contains the letter "L", use upper case.  If your callsign contains the letter "o" use lower case etc.  The problem is that the capital letter "I" is hard to distinguish from the small letter "l" and the numeral "1".  Similarly the capital letter "O" is hard to distinguish from the numeral "0", so always use the small letter "o".

Your SailMail password IS case sensitive, so enter it carefully.

I only go cruising for a few months at a time.  Can I start and stop my SailMail membership?
My modem stopped working.  Can I extend my membership for the time the modem was broken?
I joined SailMail before I really needed to, can I delay the start of my membership?
The dog ate my SailMail Primer and I couldn't get it to work. Can you extend my membership?
I only want to go cruising for 6 months, can I just join SailMail for 6 months?
SailMail is not a fee-for-service company like a phone company.  Instead,  SailMail is a Cooperative Association of cruisers that operates a network of radio stations for our own benefit.  It is like a yacht club where the members share the use of the clubhouse.  You cannot join and quit a yacht club on a daily basis and just be a member on the days that you want to use the clubhouse.

Memberships in the SailMail Association are only available for one year periods, and are not refundable for any reason, including changes in a member's cruising plans, or difficulties in using SailMail.  See the Terms and Conditions of SailMail on this website for more detail.

It is difficult to connect, I often get disconnected, and messages transfer too slowly, what should I check?
Only connect immediately after having fully charged your batteries.  SSB's are extremely sensitive to even slightly low battery voltages.

Eliminate all sources of interference that are on board your boat.  Run your laptop from its internal batteries rather than from its power supply.  Shut off your inverter.  Shut off all other electronics and motors.  You can identify sources of interference by listening to your SSB while you turn your other equipment off and on.   Common culprits are shore-power battery chargers (from genset also), small AC inverters, Danfoss 12v fridge compressors, some types of 12v lighting, solar-panel controllers and battery monitors. If you are in a marina then reception is bad almost by definition, even if you unplug your boat the neighbors will still be generating interference.  The best test is to turn off everything except the radio, and listen carefully for weak signals. See Airmail help for "slow connections" or send a blank email to: rxhelp@saildocs.com for more info.

Listen to your boat's signal from another boat's radio.  Your signal should sound exactly like the station's.  If it sounds higher or lower in pitch, then you are off frequency; check the relevant question below.  If your signal sounds garbled, then your SSB may be getting low voltage, it may be over-driven, or RF may be getting into the wire between the SSB and the Pactor-modem.  Fully charge your batteries just prior to using SailMail, check the drive-level application note, and add ferrites as described in "Installation Basics."

Check that your Clarifier, Clarity, or RIT control is centered or turned off.

Check that while transmitting during a SailMail connection that your SSB draws about 10-15 amps more during transmit than during receive.  If it doesn't you either have your modulation levels set incorrectly or may have a bad connection to your tuner, antenna, or ground.

Check that your tuner is actually tuning.  For example on an ICOM radio the radio should indicate "TUNE" after you've pressed the tune button and the relays have finished clattering.  If the radio instead indicates "THRU" or "SWR" then you may have a bad connection between the tuner and the antenna, or between the tuner and the ground system.

I don't own any equipment now but I want to buy a SSB and Pactor-modem etc.  What should I buy?
The current all-star list is as follows:  Icom M802 SSB, Icom AT140 tuner, SCS P4dragon DR-7400 Pactor-modem, remote control cable to remotely set the frequency on your M802, Radio Works T-4 Line Isolator, and 12 ferrite chokes scattered about on all of the cables.   An insulated backstay is the best antenna, with the antenna tuner located just below it under the deck.  For a counterpoise (ground) use an external keel,  ground plate, screening along the hull, engine, and/or metal tanks, connected via a copper tape.   For sources see the "Installation Basics" section, and the opening page on this website.  For information on how to set up your AirMail software and wire the remote control cable to allow remote tuning of the Icom radio, see the Application Notes

I find the SCS Pactor modem model numbers absolutely baffling and I get confused between the hardware model number and the pactor mode number.  Can you give an overview?  Which modems can use the Pactor-III mode?  Which can use the P4 mode?
SCS model numbers and pactor modes are confusing.   Current modems in production are the PTC-IIIusb and the P4dragon.    Any previous PTC-II, IIe, IIex,  IIpro, or IIusb modem can be licensed to use the Pactor-III  protocol for a fee (paid to an SCS dealer or to SCS, not to SailMail) but can't be used for P4.   Pactor-III transfers data 3-4x faster than Pactor-II with good signals, and is slightly faster than Pactor-II even with weak signals. P4 is faster still.  We strongly encourage all members to use at least Pactor-III.  SailMail's stations are all capable of all modes including Pactor-4.  We expect that PTC-II-family modems (licensed to use Pactor-III) will continue to be used by most SailMail members because of the significantly lower cost. But for those with greater communications needs, Pactor-4 offers a good way to increase capacity. 

Pactor-III mode was developed after the PTC-II and PTC-IIe were introduced, and was an "option"-- part of the newer firmware-updates but had to be "unlocked" with a purchased license-code.  For later modems this Pactor-III license-code was keyed to the modem's electronic serial# (ESN) and was transferable with the modem. For earlier modems, all PTC-II's and early production PTC-IIe units, without an ESN, the original policy was for SCS to issue a license code that was keyed to the user's callsign. This license-codes are not transferable to a new owner and are no longer available.  If you have a PTC-II or early PTC-IIe that does not have an ESN (i.e. no barcode sticker on the bottom), it may be possible to have the modem retrofit with a hardware ESN.  contact Gary at Farallon Electronics to find out.  If it is possible, the ESN retrofit and P3 license will cost around $350.

In any event, leave the modem selection in AirMail set to your modem model number.  If your modem has indeed been upgraded to Pactor-III mode then Airmail will detect that, and use it.

The best way to find out the Pactor-III status is to connect the modem to the computer (no radio needed), open Airmail and open terminal window, and wait a few seconds for the modem to initialize. The initialization string will show the modem serial# is there is one, and the Pactor-III license status.

Can you give me a historical summary of all Pactor modems?  I'm still baffled by the names and numbers.  I'm potentially interested in buying a second hand SCS modem from a friend or from Ebay and I need to know what I'm getting into.
OK here goes...  Remember that we didn't come up with this complicated approach to hardware versions, protocol-modes, upgrades, and licensing.  But here is a summary.

SCS Pactor Modem Guide

Model numbers are shown on the front panel, e.g. PTC-IIe or PTC-IIpro. The original PTC-II was an all-metal box, the later modems have gray plastic bezels around the front-panel. (Current SCS modems-- DR-7400/7800 and PTC-IIIusb) have black plastic bezels).  The early modems were all PTC-II models of various sorts which may or may not have been upgraded to enable Pactor-3 mode.  No PTC-II or PTC-III modem of any type can be ungraded to run P4.    All SailMail stations support Pactor-II, Pactor-III, or P4.

From oldest to newest (see below for explanations of terms):

PTC-II (no suffix, original all-metal box):
    Serial, TTL radio control, P2, No ESN.
PTC-IIe: Serial, No radio control.
    Early PTC-IIe's have no ESN (no bar-code label on bottom), P2
    later PTC-IIe have ESN (same as PTC-IIex), P2/P3*
PTC-IIex: Serial, No radio control, ESN, P2/P3*
PTC-IIpro: Serial, full radio control, ESN, P2/P3*
PTC-IIusb: USB, full radio control, ESN, P2/P3*

The current modems (PTC-IIIusb, DR-7400, DR-7800) are all USB.  The PTC-IIIusb supports Pactor-II and Pactor-III.  The DR-7400 and DR, support Pactor-III and P4.(no license-code needed),   Again, all SailMail stations support P-II, P-III, and P4.


Serial: 9-pin serial computer interface, generally requires a USB/serial adaptor (we currently recommend any of the devices with a FTDI chip set, e.g. search Amazon for "FTDI RS232"

"TTL radio control" is the original 8-pin "control" connector, TTL (0-5 volt) radio frequency-control only, compatible with M700pro, M710 (not M802).

"Full radio control" is 13-pin "control connector", either 0-5v or RS232 levels, compatible with pretty much any recent radio to set frequency.

ESN: Electronic serial #, stored internally and also on a paper bar-code label on the bottom of the modem. It is used as the "key" to an optional Pactor-3 license (unlock-code). Early modems without ESN can be upgraded to add the ESN chip, only a few have been.

P3*: Units with an ESN *may* have been upgraded to P3 with a license code, most were. These license-codes are transferable to a new owner. The code itself will be stored in the modem (unless somehow erased), and can be checked or retrieved from SCS via email (info@scs-ptc.com).

A modem with ESN, but which was never upgraded to P3, can be upgraded with the purchase of a license-code, cost is around $200 (contact Gary at Farallon Electronics in Calif, garywood@farallon.us).

Exceptions: Early, non-ESN modems could originally be used in P3 with a different code that was keyed to the user's callsign. These codes are NOT transferable, and no new callsign-codes are being issued by SCS. It *may* be possible to upgrade these modems first with the addition of a ESN chip, then by purchasing the P3 license code, cost for all that will be around $350-- contact Gary at Farallon.

If buying a non-ESN modem (PTC-II, early PTC-IIe) it is important to determine whether it has the ESN upgrade chip. For PTC-IIe, check for the bar-code label. Without the ESN the modem can only be used in P2 mode, works just slower. Upgrading to ESN (and P3) is expensive, check with Farallon and consider that in the price.

ESN modems may or may not have been upgraded to P3. If so, the license code *should* be stored in the modem: Connect to a computer, start Airmail and configure modem-type and com-port correctly, open terminal window and confirm that it initializes. The initialization message will show 13-digit ESN and Pactor-3 license status.

Alternately open a terminal program (Hyperterm or Airmail's dumb-terminal window), hit ESC to get a "cmd" prompt, type the "LICENSE" command to see the license-code (if stored). The command "SYS SERN" will show the serial#.

Can I operate SailMail with an Icom IC-718 HF Ham transceiver?
The Icom IC-718 and most other ham radios work with Sailmail if they are equipped with a High Stability Crystal Unit, and if the radio is modified to transmit on all bands.  For Icom ham radios you need to select "Icom-CIV" as the radio type in Airmail's radio settings. Ham radios are not type accepted for use on marine frequencies and their use may not be permitted by your country's radio regulations. For US-registered vessels, the US FCC requires marine type-accepted radios (e.g. Icom M802, M710, M700Pro etc)

There is another reason why it is a bad idea to use a Ham radio...  Ham radios are much more complicated to operate than marine radios because they have many features that marine radios don't need.  If these options and features are set incorrectly the radio will not work.  Often on a cruising boat there is only one knowledgeable ham onboard.  If that person is injured and others need to use the SSB, they will be much less likely to be able to operate a Ham radio than they would a marine radio.  Note that it is perfectly legal to use Marine radios such as the Icom M802 on Ham frequencies.  This is a better approach.

What are the best frequencies and times of day?
I've heard about a propagation tool, what is it for?

Be creative; avoid using the station in the mornings or evenings when it tends to be most crowded.  Try in the middle of the night to help pass the mid-watch or anchor-watch.  Generally the highest frequency that works will give you the best transfer rate because there is less multipath, even if the signals are somewhat weaker on the highest frequency.  The 13 and 18 MHz frequencies work best in the afternoon, generally at distances over 1000 miles.  The 5 and 7 MHz frequencies work best during the night or early morning, generally at distances under 3000 miles.  The 2 MHz frequency works for short distances of several hundred miles (particularly at night), and 10 MHz is a pretty good bet just about any time for distances over 1000 miles.

AirMail has a propagation tool that will help you figure out the best times and frequencies.  If the nearest station is busy, it will  help you find good times to connect to more distant stations that may not be busy.  Some SailMail members routinely connect to stations that are one third of the way around the world that are lightly used; be creative.  The propagation tool is available by going to the Download page on this website, then selecting the AirMail Download Page, and then scrolling down to find the paragraph on propagation and selecting the NTIS/ITS website.  When you install the propagation tool, accept all defaults on the installation.

How do we periodically update our position on the propagation page so that our location is permanent and accurate for the propagation tables??
Go to AirMail's Tools menu, Options window, settings tab- upper-right.
Or, open Window menu, Position reports- enter lat-lon and click "Now" button to let Airmail know when it is valid.

How many simultaneous connections on different frequencies can a SailMail station handle?
Some SailMail stations operate multiple radios, and can connect on multiple frequencies at the same time.   Those stations are so noted in the table of stations and frequencies in this Primer.

The other SailMail stations have just one transceiver which scans all of the frequencies when it is not linked to a user. When it receives a call, it stops scanning until the user finishes and disconnects. A single-radio SailMail station can only support one connection at a time.   It causes no interference, but it is nevertheless fruitless, to try to connect to a single-radio station when the station's transceiver is busy on another frequency.

Many members find it useful to listen to the various frequencies assigned to a station to see what a single-radio SailMail station is up to, and wait for the station to be open before calling.

If you are trying to connect to a multiple-radio SailMail station, just make sure that the frequency on which you are trying to connect is not in use before connecting.

I've seen different descriptions of what cables that I need between the laptop, modem, and radio.  What's the story?
It all depends on which modem you have.  Most modems have a radio-control cable that goes from the modem to the radio.   The smaller PTC-IIe and -IIex models do not have a radio-control connector, and controlling the radio requires an additional COM-port on your laptop, so in those cases the radio-control cable goes from the additional Com port on your laptop directly to your radio.   Just to add confusion, the original PTC-II had a control port but with a different connector, and only for non-RS232 connections.  The cables are available from most dealers or from Farallon Electronics in Calif (the SCS distributor).   There is a useful chart at www.farallon.us  Go to their page for "Articles and Technical Information" and then look at the "SCS PTC Modem to Radio Model Cable Reference Chart".

My computer has a USB port, but has no conventional serial or RS232 ports.  How do I hook up the HF modem?
I have an SCS PTC-IIe or IIex and need another serial or RS232 port to use to remote control my radio
How do I add another serial port? 
I want to also connect my GPS NMEA output to the PC and need another serial port, how to I do that?

If your laptop has USB ports, buy a USB to serial port adapter.  Our recommendation is any of the adaptors that use the "FTDI" chip.  Search on Amazon for "FTDI RS232" and you will find many options.  Make sure that the unit you buy is labeled for your operating system, e.g. Windows 7,8,10. For more detail see the application note on serial ports or send a blank email to serialports@saildocs.com

I ignored your advice above about USB-to-serial adapters and instead bought an obscure brand, cheapo, USB-to-serial adapter.  Whenever I open the Terminal Window AirMail complains, "No Ready Signal (CTS) from COM1".  What should I do?
The problem is that some simple/cheap USB adaptors do not include all of the serial-port control wires.

Start Airmail, open Tools menu, Options window, connection tab. Click the "advanced settings" button, and check the box that says "Ignore COM-port CTS signal". Close that window, double-check the com-port and baud rate (57600 recommended), click OK. Then power-cycle the PTC-II, and open Terminal-window. After a 3-5 second delay, you should see the "initialized OK" message on the window and the left-most buttons will turn green/red.  For more detail see the application note on serial ports.

I have installed an USB to RS 232 adapter but I can't find the proper COM port.  I might not even have the right drivers for my updated version of Windows.  What should I do?
If you can find the manufacturer and model# for the USB adaptor, then go to the manufacturer's website and find the drivers. Follow the instructions there.  If no success there, the best option may be to find a new USB/serial adaptor, with drivers included for your version of Windows. Our recommendation is any of the adaptors that use the "FTDI" chip.  Buy from a shop that can provide some help, and be sure that drivers are included for your version of Windows.

Once you have the USB adaptor installed correctly, then Airmail should recognize the adaptor-- it will be the highest-numbered COM-port in Airmail options.  Or, open windows device manager (from Control panel, after selecting "small icon" view). Look under "ports" for the USB adaptor, the COM# is shown there. 

Open windows device manager (select "computer" icon, right-click and select "properties", or open control-panel, system (you may need to select "view all icons" or similar).
Device Manager shows all hardware devices, scroll down and find "ports", click the little "+" to expand that and look for your USB adaptors-- then should be there, showing the com-port.   Alternately, start Airmail and open Options window, connections tab. Click the little arrow on the modem com-port box, that will show all available ports. The last selections will usually be the most-recently installed, i.e. the USB devices.   Sometimes it helps to connect and disconnect the USB adapter and look for the changes in device manager.

How can I update my version of AirMail without losing my address book and my old messages?
AirMail downloads are self-installing "zip" files that are designed to gracefully upgrade existing installations of AirMail leaving your old messages and settings intact, and will automatically update your information about new SailMail stations.  Just download the newest version from the download page of this website, and then run the download file in order to install/update your installation.  It never hurts, however, to make a backup before you install new software.

How can I update my installation of AirMail with the latest information about SailMail's new stations?
If you have access to the internet, you can download the latest version of AirMail from the download page of this website, and run it.  That will upgrade AirMail's information about the stations, as well as make sure that you have the latest version of AirMail.

If you are off at sea, without internet access, send an empty email to stations@saildocs.com   That will cause an email to be sent to you that will automatically update the data within your AirMail software with the latest information about SailMail's stations and frequencies.

How can I un-install the AirMail software and other related programs?
All you need to do is delete the Airmail folder from wherever you installed the program, the default is "Program Files" on the hard-drive.  If you installed the propagation program then it is all contained in the "itshfbc" folder on the c-drive, so delete that folder as well.

My SailMail installation and AirMail software have been working fine, but I am ashore and have access to the internet.  Should I upgrade AirMail?
Yes.  AirMail is always getting better and you might as well take advantage of the improvements and bug fixes.  The price is right (free).   While you are at it, get a new copy of the pdf file of this primer and keep it onboard.  The pdf file has a link near the top of this Primer.

What can I do about SailMail "newbies" that try to connect when the Station is busy?
Education is best approach.  If you put your Pactor-modem in monitor mode, you may be able to work out who the member is who hasn't figured out how to use the station correctly.  If there is a member who repeatedly tries to connect while a station is already connected, send an email to sysop@sailmail.com with the members callsign, and we will send them an email summarizing recommended operating practices.  If you happen to know them or share an anchorage with them, you might GENTLY educate them.

I can send messages, but I often get disconnected or have trouble receiving messages?
Generally this happens if you have a source on RF interference on board.   Common sources of onboard RFI are your laptop power supply, inverters, Danfoss refrigeration compressors, and any other motors.  Try running your laptop off of its internal batteries while using SailMail, and try shutting off all other inverters, motors, and electronics.  If you listen to your SSB while turning gear off and on, you can often identify the offending piece of equipment.

Where can I get a laptop power supply that works on 12 volts DC, but won't cause interference on my SSB?
A variety of 12v adapters are available, but be certain that the converter that you buy is approved for use on airplanes.  The FAA certified converters are much better designed and produce much less interference than the automotive-only products.  Many laptop manufacturers sell FAA certified power supplies that are intended for use with their laptops.  It can't hurt to clip ferrites on the input and output of the laptop power supply.

How can I tell if my SSB is on-frequency?
If you have a SCS PTC-II modem, open the AirMail Terminal Window, set the frequency on your radio to the highest channel of WWV that you can receive clearly (10, 15, or 20 MHz), and set the frequency on your radio to WWV minus 1.5 kHz (if you use 1500 Hz tones).  For example, if you are listening to the 15 MHz WWV, set the radio to 14998.5    If your radio is set up to be remote controlled by AirMail, then type the exact WWV frequency (e.g. 15000.0) into the frequency box at the top of the Terminal Window and AirMail will subtract the tone frequency for you and set the frequency on the radio for you. 

The PTC lights should be centered.  Each LED off center is 10Hz.  By changing the frequency up and down a bit, you can use this technique to see whether your radio is accurate to within 1 Hz.  If the radio is more than 2 LED's off, (20 Hz) you should get it adjusted the next time you have access to a marine electronics technician.  If it is 4-5 LED's off, you will have trouble connecting to SailMail stations.  If you get your radio adjusted by a technician, be sure to check his/her work with WWV.  Let the radio warm up for 10 minutes or so before doing this test; many radios are off frequency for a minute or so after first being turned on.

If you do not have a SCS PTC-II modem, or want to try another method,  let your SSB warm up for 10 minutes and then set your radio to WWV on 10, 15, or 20 MHz.  Wait until WWV is transmitting an audio tone.  Change your radio back and forth between USB and LSB modes.  The pitch of the audio tone should stay exactly the same.  If you can detect a difference in pitch, the frequency standard in your radio is not adjusted correctly and should be adjusted the next time you have access to a radio technician.  Musicians are particularly adept at this approach, and can detect a frequency error of just 2-3 Hz by ear.

Finally, if you are using a SCS PTC-II, watch the display as soon as you connect with any SailMail station.  The center LED should light up colored red.  If instead the lit LED is off center, that indicates that your radio is not on frequency.  For every LED that you are off center, your radio is approximately 10 HZ off frequency.  Once you are connected, the lit LED will slowly migrate to the center as your SCS PTC-II accommodates your radio's frequency error.   Get your radio adjusted if it is more than 20 Hz off.

Can I use SailMail in a distress or emergency to communicate with the Coast Guard or other Search and Rescue Services?
Get a grip.  If you had a family member who was badly injured in your house, would you send an EMAIL to summon an ambulance?   The Internet is neither fast enough nor reliable enough to be used for true distress or emergency communications.  

Once you have contacted a Search and Rescue Service, they MAY ask you to send them periodic updates via SailMail.  That is a customary and reasonable use of Internet email, but again, do not depend on the Internet for your initial communications regarding a distress situation.

In a distress situation first try to communicate by voice directly with the Coast Guard or other maritime search and rescue organization.   If you can't reach them, then try for any human (ham or otherwise) on any channel.   Only by communicating with an actual human can you be (nearly) sure that your distress information will be passed all of the way to a rescue organization, and not end up in a "bit-bucket" somewhere as a bounced message.   

The U.S. Coast Guard monitors the International Distress channels that are listed in the table below. 

International Distress Channels

ITU  CHANNEL simplex channel kHz


If you cannot reach the USCG or other maritime search and rescue organization, and want to try to reach a ham in a distress situation, try 14313 kHz USB on the ham bands, and announce "break break" with your emergency information.

How do I apply for my Ship Radio Station License and Restricted Radiotelephone Operator Permit?
To receive a ship station license, contact the relevant radio license authority for your vessel's country of registration.

If your vessel is US registered, you DO need an FCC Ship Radio Station License and Restricted Radiotelephone Operator Permit to operate your SSB.

If you have Internet access, you can file electronically.  If you file electronically, you can get your permanent callsign right away.  There are instructions available at:  http://www.offshorestore.com/services/selfhelp/communications/fcclicense.htm

If you have to, or want to, file via paper, you will need to obtain and fill out FCC form 605.  This form generally comes with new radios and is available at most marine electronics dealers.  Additionally it is available on the internet at www.fcc.gov/formpage.html   You will also need form 1070Y, which defines the fee that is due with the application, and form 159, which is the remittance form.

When you fill out form 605, on Schedule B item 9,  request a MMSI number if you don't already have one.    It costs nothing extra to get a MMSI number if you request it on your original application, but it WILL cost extra later when you buy a DSC radio and want an MMSI number.  You would then have to file a license amendment with the FCC to request an MMSI, and pay extra..  

You will also need a Restricted Radiotelephone Operator Permit, which you can get using form 753.  The operator permit does not require a test, and lasts forever.

For US vessels, note that even though the Ship Station License sounds as though it is the ship that is the licensee, it is not.  The owner of the vessel is the licensee.  So if you buy a second hand boat, you need to get your own Ship Station License, even though the boat had a previous license.  If you sell your boat and buy a new one, you will not be able to use the callsign that you used on your old boat; you will need to apply for a new license for your new boat.

Can I transfer my FCC license?
Specifically, you can not transfer the FCC callsign from your previous boat to your new boat, nor can you use the callsign that a boat already has when you buy that boat.  Net, when you get a new or second hand boat, you need to apply for a new FCC license even if you previously had a license on your previous boat and even if the boat you just bought previously had an FCC license.   Don't complain to us or argue with us about the FCC rules, but do face the music and get your new FCC license.  We WILL check the FCC database when you apply for membership, so save us all time and get your new license BEFORE you try to join the SailMail Association.

I've noticed that SailMail appends a "footer" or "signature" with information at the bottom of the messages that I send.  Can I shorten or omit it?
SailMail appends a "footer" or "signature" with instructions on how to respond to your message at the bottom of every message that you send.  For addresses that are clearly bandwidth-constrained e.g. addresses at: SailMail, SeaWave, Globe Wireless, SatMail, C-Link, Orbcomm, StratosMail, etc., SailMail instead appends an abbreviated "footer".  If your addressee has limited bandwidth, but has an email address that SailMail does not recognize as being bandwidth-constrained, you can instruct the SailMail system to send the abbreviated "footer" by including in your message a line beginning with the command: "short-footer" (don't include the quote marks when you type it into your message).  The "short-footer" command itself will be suppressed and will not be included in your message unless there is additional text on the same line.  Similarly you can insert a line containing "no-footer" (without the quote marks), to completely eliminate the footer.

When I am replying to an imcoming email, is there a convenient way to include a part of the incoming email in my reply?
You can copy/paste questions or excerpts (for readability) by selecting and copying, and then selecting "Paste >Quote" from the Edit menu.

My laptop clock seems to be set correctly, but the UTC time displayed by AirMail is incorrect.  How do I fix it?
In Windows, go to Start, Settings, Control Panel, Date/Time, and check your settings. The problem is likely due to the fact that either you are set to the wrong time zone, or you do not have the box checked that says "adjust automatically for daylight savings time." Either of those reasons will cause Windows to incorrectly compute the Zone Correction, and thus UTC will read incorrectly.

If you leave your laptop set to UTC, then you must choose the Zone labeled "(GMT) Casablanca, Monrovia."  The other GMT selection that includes "Dublin, Edinburgh, Lisbon, London" does not work correctly in handling/ignoring daylight savings time.

Can SailMail handle attachments like executables, jpegs, spreadsheets, Word docs, pdf's, etc?
What is the length limit on normal messages
Only a few attachments are small enough to make sense transferring over SailMail given the recommended connect-time limits of 90 minutes per week.  SailMail does allow grib files ( with file extensions .grb or .grib) to be transferred if they are under 30kBytes in length using Pactor-III and 40kBytes if using Pactor-4 PredictWind weather data attachments with .pwu file extension are similarly passed with the same file lengths.  Fleet Code attachments (with file extension .iac) can be transferred if they are under 15kBytes in length.   SCS license files (with file extension .lis) can be transferred if they are under 2kBytes in length.  Small .csv .ems and .TLE  files are also passed.   Other types of attachments are not passed. The connect time limits continue to apply, however, so use this capability sparingly.   The above attachment sizes assume that you are using Pactor-III or Pactor-4.  If you are using Pactor-II then the limits are smaller, typically about half.   No executable attachments are passed for security reasons, and all attachments and messages are scanned for viruses.  Attachment types not mentioned above are not passed.

The length limit for a normal message is 20kBytes for Pactor-II, 35kBytes for Pactor-III, 50kBytes for Pactor-4.

Because you can control what you send, you can SEND any type or length of attachment and any length message, but do watch your radio connect time and don't try to send overly long messages or attachments.

If you are a Ham you can access the Winlink-2000 mbo's; see the Airmail website (www.airmail2000.com) for info.  The ham systems generally have no connection-time limits and DO allow the transfer of large files such as .exe and .jpg attachments, although you will not make many friends if you tie up a Winlink mbo for hours trying to send an executable or a photo.

Can I use my computer's soundcard as a Pactor-modem for SailMail?
Can I use my Xaxero/Coretex (or other) weatherfax demodulator as a modem for SailMail?
Can I use my regular telephone modem instead of a Pactor-modem for SailMail?
The sales brochure for my SSB says it is "data ready,"  do I still need a Pactor-modem for SailMail?
You need to use a Pactor-modem in order to use SailMail.     Nothing else will work. 

When I turn on my GPS or AIS, my cursor bounces all around my computer screen.  How do I fix that?
What you are experiencing is common when a GPS or AIS is connected via a serial port.  Windows incorrectly thinks that the incoming GPS or AIS data is a serial mouse and dutifully installs the appropriate driver. Then suddenly you have a cursor dancing all over your desktop.

To fix it, once the problem starts and the cursor is bouncing around, leave the GPS and AIS plugged into the PC, but turn them off so you can regain control. Next go into the Windows Device Manager (right-click on "My Computer" and then click on "Properties" and the click on the "Hardware" tab and then the "Device Manager" button) and look under the "Mouse and other Pointing Devices entry. You should see one or more "Microsoft Serial Ballpoint Mouse" entries. Right-click on each one and select "Disable" Do not "Delete" or "Remove" or they will only come back.  You might have to do this two or more times.

I bought a new Icom M802, M710 (or M700Pro), but it doesn't transmit on SailMail frequencies.  Did I buy the wrong radio?
Yes and no.  You purchased a radio that is set up for the marine bands only. SailMail's frequencies are specifically permitted for marine use by members of the SailMail Association, but some are outside the traditional marine band.  Icom's marine-only model is configured to only transmit on the traditional marine bands: 4-6 MHz, 8-10, 12-14, 16-18, etc. The all-band model transmits over the entire 1.6-30 MHz range.

What you need is a radio that is enabled for all-band transmit (this is the lockout that is mentioned elsewhere in this Primer). The good news is that it is the same radio, with a different setup.  Any Icom dealer can change the radio setup; the change requires a special setup program and cable and takes about 10 minutes. Start with the dealer you bought the radio from.  If you need to go to another dealer there will be a charge for the service.

If your radio is an Icom M802, see the instructions in the M802 application note which is attached to this Primer.

I have been using SailMail, and just got my ham license.  I want to set up AirMail to work both on the ham Winlink network, and on SailMail.  How do I do it?
Go to the downloads page of the SailMail webpage to find links to both the Ham and SailMail versions of the AirMail program.  The Ham version of AirMail should be installed first, and then the SailMail version. The order is important as the ham version does not include a complete Saildocs catalog.   Install the most recent versions of AirMail.  That's it, no other software is required. Specifically do NOT install "Winpack", "Paclink" or any other software from the Winlink website, it is not needed and will just confuse things. If you have already installed the SailMail version, then install the Ham version into the same folder as your existing AirMail software that you use for SailMail.  When you are done installing the Ham version, then download and re-install the complete SailMail version.  For more detail and the latest tips, send a blank email to bipolar@saildocs.com or see the application note section of this Primer.

I understand that ham's use 2100 Hz tones and LSB, whereas the SailMail recommendation is to use 1500 Hz tones and USB.  I am a licensed ham and I want to use both SailMail and also the ham Winlink stations.  Do I need to have two AirMail installations with different setups?
No.  The convention which we recommend for SailMail members is to use USB and 1500 Hz tones.  Hams have historically used 2100Hz tones and LSB.  AirMail does all of the arithmetic and conversions, so if you have a marine radio and have it sensibly set up for USB  and 1500 Hz tones, it will work without any changes if you want to use it for ham Winlink stations.  Just select the ham Winlink mbo frequency at the top of the AirMail Terminal Window, and AirMail will do all of the necessary arithmetic and show you the correct frequency to set the frequency on your radio to in the box at the bottom of the Terminal Window.  If you are set up for remote control, AirMail will  remote set the frequency on your radio.

My messages show an ID number that refers to my ham callsign even though I'm using SailMail?
No worries.  If you have set up AirMail to work both on the ham networks and on SailMail, AirMail will end up using your ham callsign for the unique message id's that it assigns to each message.  This is just a peculiarity of AirMail; your SailMail messages will still be correctly addressed to and from your marine callsign, and your transmissions will be correctly identified with your marine callsign.  If you are not a ham, and for some reason you see a "Ham" tab under Tools/Options/Settings, then just enter your Marine callsign there as well as under the SailMail tab.

I am pretty certain that I saw a bug in SailMail; a message was dropped, duplicated, corrupted etc.  What can I do to help SailMail fix the problem?
First, make sure that you are using the latest version of AirMail because it is possible that the bug you found has already been fixed. Second, read the above FAQ's to make sure that it is a real problem; sometimes messages appear to be dropped but it turns out that you already have downloaded them.  Next, dig through your capture.txt files that are in \program files\airmail\capture and find the section where the bug appeared.  Send this excerpt from your capture.txt files to sysop@sailmail.com along with the date, time, SailMail station/radio used, your AirMail version number, and all other information about what happened and why you think it is a bug.  Finally, don't get too impatient with us while waiting for a response; these things are tricky and we have day jobs.   Thanks in advance for helping.

The most common reason for "missing"  messages that are sent from vessels is that the member on the vessel changed the "email gate" box in airmail's message window. This parameter is used to route the message to the internet gateway. For SailMail it is always "email" (not case sensitive).  "Nexus" also works. Airmail uses "email" if it is left blank. Similarly, if the member on a vessel sends a message to an address that does not look like an internet address (i.e. it does not contain an "@" character) then that message will not be sent over the internet.

We don't know of any holes for properly addressed messages sent from the internet to the vessel to fall into. Users can easily check for missing messages themselves, as messages get numbered sequentially per user-callsign.

My vessel is registered in Canada, and somebody told me that I do not need a Ship Radio Station License.  What should I use for my vessel callsign when I apply for membership in SailMail?
It turns out that you really DO need to get a Canadian Ship Radio Station License for your vessel in order to join and use SailMail.  There are two aspects that trigger the requirement for the license.  First, SailMail operates outside the frequency bands that Canada defines as "license-free."  Second, if you intend to operate your vessel outside Canadian and US waters you will need a ship station license in any event.  So apply for a Canadian Ship Radio Station License, and when you get your callsign you can join SailMail.

I would like to send in position reports via SailMail for plotting on the Pangolin Web site using the Yotreps position report form in Airmail. It appears that I just fill in the data and hit "send now".  Can I use the position report form as is or do I have to do something else?
Use the Airmail "yotreps" window, it formats an ordinary email message which works fine with SailMail. Fill in the blanks, click "send now", and you can check the resulting message in your outbox before connecting to SailMail. (You can also add any comments to the bottom). Select the "pangolin@xtra.co.nz" to send it for real, the "mike@pangolin.co.nz" address for a test message.

Do you have a blog site for members or a diary update or a map position update facility?
We don't have our own blog site, but we recommend www.sailblogs.com    SailMail does provide a template for sending your blog updates to the Sailblogs website.  In the Airmail program go to Window, then SailBlogs. There is also a position tracking map that they offer as well.  Another service offering position reporting is Yotreps (http://www.pangolin.co.nz/yotreps/). In the Airmail program there is a template found by going to Window, Position Reports for both of these options.

How do I send updates to Sailblogs?
In the AirMail Message Index Window, click on the "Window" tab and then select "Sailblogs."  In the Sailblogs Setup Window, t
he "send to" box is the email-address for sending updates, this was provided when you signed up for Sailblogs' premium service (which is required in order to update entries via email).  It will be an email address, typically something@x-journal.net (not "www.sailblogs.com"). The "key" is also provided by Sailblogs when you sign up, usually some variation of your boat name.  There is some information on the Sailblogs website, in the how-to "wiki"

In the primer I read that I should not interfere with the default Inbox and Outbox folders.  Can I make any changes to the folders?
You shouldn't mess with the default Inbox/Outbox folders (airmail's tools/options, folder tab, right-hand side) but you can certainly create new folders and move messages around as you wish. You can create new folders with the tools/options window, folder tab- left side, or by right-clicking the "folder tree" in the index window. You can open any folder (or combinations of folders) by clicking them in the folder tree (use shift-click to open multiple folders at the same time), and you can drag one or several messages by selecting them (with the usual windows mouse or keyboard shortcuts) from the message index and dragging into a folder. Or you can select messages, then use the File/Move menu. Remember that deleted messages go into the "trash" folder, don't forget to empty that periodically (messages deleted from trash are deleted permanently). There is some additional info in the airmail help file, contents/Airmail windows/Using the message index.

Can I clip on multiple ferrites on the coax between my radio and tuner instead of using a T4 Line Isolator?
This gets
a bit complicated.  One could imagine that you could simply clip on the 1/2 inch hole, #31 ferrites onto a coax and have it work as well as a line isolator. Unfortunately, those toroids have a "closed" magnetic path and therefore are easily saturated by DC currents. It is likely that some of the tuner DC power current will return via the coax shield, and if this happens, the clip on ferrites will likely be saturated by the DC current on the coax and therefore not do much good. If it were not for the DC currents, it would take about 5 of the ferrites to do a good job (partially answering your original question).

One approach that can create an effective common-mode choke in the coax between the radio and tuner is to get a ferrite rod, and take about 15 turns of skinny 50 ohm coax around it. Teflon coax is a good choice here, because the rod can get hot if there is a lot of common-mode RF. An Amidon R61-05-400 rod is a good choice (.5 inch diameter and 4 inches long). Because the rod has an "open" magnetic path, it doesn't get saturated by DC current in the coax (from the tuner power).  As it turns out, if you do this you will have essentially home-built a T4 line isolator.  It is easier to buy one all nicely packaged with connectors, and the price is right (www.radioworks.com).

My computer is failing.  How do I back up my AirMail installation?
The important things are the following files from the Airmail folder (usually c:\program files\Airmail):

Airmail.ini (settings)
Addrbook.txt (address book)
(for ver-3, also the following:)
System.sailmail.ini (sailmail stations)
xxx_sp.adl (personal spelling dictionary, xxx is your windows user-name)

That's the basics, and won't take much space on a USB thumb-drive. Use Windows explorer to open the airmail folder and copy those files to a thumb-drive. You can then re-install the Airmail download file, copy those files into the Airmail folder, and be all set up.

You may also want to save your messages.  You will find them in the Inbox and Outbox.  Copy them to the new computer as described above using a thumb-drive.

With Vista, Win7,8,10 it is a bit more tricky...  On the post XP operating systems, the data files are stored in the Airmail folder under the "ProgramData" folder, on the hard-drive. Open that folder and copy the "addrbook.txt" file there.  Your old messages are also in the same locations, in the various "inbox", "outbox" folders.  

Note: Windows does not like to show the contents of system folders: From Winows Explorer or the "My Computer" window select "Tools" menu, then "Folder Options". Click the "View" tab, and check "Show hidden files and folders", NO check for "Hide file extensions for known file types", NO check for "Hide protected operating system files" (and click "Yes" to the confirmation). This will show all files, and also show file-extensions.

Can you tell me how to print out my SailMail address list?
The simplest method is to use Airmail's Export function (Tools/Address-book/Export-addresses) to save it as a "CSV" file, which can then be opened with Excel or some other spreadsheet program, or a word-processor. This will allow you to do whatever you want with formatting.

The address info itself is stored as a text file (addrbook.txt) which can be copied or saved.  In a typical installation the addrbook.txt file is in the "c:\program files\airmail\"  folder.

On the vista computer the data files are stored in the Airmail folder under the "ProgramData" folder, on the hard-drive. Open that folder and copy the "addrbook.txt" file there.

Note: Windows does not like to show the contents of system folders: From Winows Explorer or the "My Computer" window select "Tools" menu, then "Folder Options". Click the "View" tab, and check "Show hidden files and folders", NO check for "Hide file extensions for known file types", NO check for "Hide protected operating system files" (and click "Yes" to the confirmation). This will show all files, and also show file-extensions.

I have been using SailMail for some time, and just bought a new computer and installed a fresh copy of AirMail, do I need to update my message id number?
AirMail keeps track of the last message number that it has used for messages outbound from your vessel.   If you change computers, this number will be set too low, causing the SailMail system to suspect that you are trying to send duplicate  messages.   You can reset your message id number in AirMail under: Tools/Options/Settings/Current Message Number. 

Do I have to worry about getting a virus from messages that I receive via SailMail?
No.  Viruses are passed as attachments to email or downloaded from url's that are included in email messages.  The fact that SailMail only passes plain text messages means that no virus can be carried in a SailMail message, to or from your vessel.  SailMail does pass certain attachments, but only attachments of a type that are non-executable and so can not carry viruses.   As yet an additional precaution, the SailMail system scans all messages for viruses and deletes any messages that carry viruses.

If you take your PC ashore and connect to the Internet via dial-up access or at Internet cafes, you WILL be subject to infection by viruses.  It is a good practice to install a virus checking software package, and periodically scan your PC for viruses using virus definition files that you can update whenever you have access to the internet.  Norton and McAfee both offer good antivirus products.  We recommend buying and installing one of those packages and following their recommended procedures.  For advice on computer security send a blank email to security@saildocs.com

Is there a health problem due the RF from my SSB?  How far away should my crew stay from the backstay when transmitting?
There is an IEEE (Institute of Electrical and Electronics Engineers) standard (C.95.1) recommending the maximum human exposure to RF energy.  If you use SailMail via a 150W radio, the standard recommends that nobody should be closer than 3 feet to your backstay or to the high-voltage wire leading from the tuner to the backstay while transmitting on your SSB (e.g. while connected to SailMail).

Does SailMail offer support for the full German (Spanish, etc.) character set?
Yes, Sailmail supports the complete 8-bit character set, including all of the German and any other language that uses Roman characters.  Sailmail simply sends whatever text is in the message, using the same 8-bit character-codes. We have many German members who are happy with the service.

Should I maintain a second normal email account (e.g. GMAIL) in addition to my SailMail account?
If I maintain two email accounts (SailMail and a non-SailMail account) what should I use them for?
If I have a non-SailMail email account should I forward it to SailMail?

You should definitely maintain a second non-SailMail email account.  Use the non-SailMail email account for anything that might attract spam, e.g. ordering stuff, posting to news groups,  and putting on any form that you are filling out that requires an email address.  Also use the non-SailMail email account for all non-urgent communications.

Do NOT forward the email from this second non-SailMail account to SailMail.  Instead give your closest friends and family your SailMail account so that they can communicate with you when you are at sea.

There are a variety of techniques, described below, for how you can retrieve your SailMail messages and other account messages either when ashore or at sea, with your boat computer or with a public computer in a internet cafe.

How can I send SailMail messages from a "blind" address.  Specifically can I have the messages that I send via SailMail have another "FROM" address on them so if folks reply, their replies go to another account?
We recommend is setting up a GMail, Hotmail, Yahoo address to use as a "public" address for ordering parts, or corresponding with associates who may not respect the privacy of your SailMail address.  You can send a message via Sailmail and specify the from address using this procedure:   Compose a new message, then (before sending) select the "Message" menu and select "Show From Box". This will show an additional box on the message-header for a message "from" address. Enter your public address there, for example GilliganOnMinnow@gmail.com    Be sure that this address is entered correctly!  Any reply will then be send back to this other address.  If you then want to check that public address via SailMail when you are on the boat, you can use our "Shadowmail" service to check that mailbox. See the page at www.saildocs.com/shadowinfo for details.  

Is there a way that ALL my mails can be automatically sent from a different, non-SailMail,  From: address?
Yes, with an INI-file change. Open the Window menu, Files, INI-files, Airmail.ini Now find the "[Settings]" heading, and below that heading line insert the following line: 

Default From-address=MyAddress@Gmail.com

except put your address in place of the "MyAddress@Gmail.com"
Follow the rest of the format above exactly. 
That becomes the default from-address which can be changed or deleted if you wish.   If deleted then your Sailmail address is used, as before.

I'm considering setting up another email address and forwarding it to my SailMail address.  Is this a good idea?

We strongly recommend NOT forwarding other email addresses to your Sailmail address. There are many reasons, the primary ones are that once you set up forwarding and then head to sea, you can no longer change the setup if that becomes necessary (i.e. if your alternate-address starts getting spammed). You can't change it without internet access, and we can't do anything to help.  Also, our spam filter is quite effective but depends on getting mail directly from the sender in order to identify bogus senders. Mail that is forwarded by a single server cannot be effectively screened by our filter.  Instead of forwarding, what we recommend is providing your (private) Sailmail address to a small number of family and associates, who you trust will respect to keep that address private. Then set up a separate "public" address at any email service, and distribute this address widely as you would with your normal land based email address. Then, if you wish to monitor this "public" address while you are away from the internet, use our "Shadowmail" service. This will periodically check your POP3 mailbox and send a list of any new pending messages, and allow you to retrieve any messages you want to read, or delete messages, or send them elsewhere, or just ignore them until you reach port.   For more info on Shadowmail send a (blank) email to: shadowinfo@saildocs.com

I want to receive email from a number of different email accounts. Is this possible with SailMail?   Should I have all of my accounts forwarded to my SailMail Account?
Our recommendation is to not forward other email accounts to your Sailmail addressReserve your Sailmail address for trusted friends and associates who won't bomb you with the latest jokes.

For your other personal and business accounts, we created a service called "shadowmail". Basically what it does is "peek" into whatever POP3 mail accounts that you specify, grab the headers (but not the message) and forward that to you via Sailmail. The Airmail software then maintains a "shadow" folder of your POP3 mailbox, showing from/to/subject and size. You can retrieve it, delete it, send it elsewhere, or (in most cases) ignore it until later. For more info see www.saildocs.com/shadowinfo   Generally, outgoing messages are sent with your sailmail.com from-address but you can override this for any message, and replies to messages received through Shadowmail are sent with that account's address.   Not using your SailMail return address is important in order to keep your SailMail address from being widely used.

Shadowmail can check GMail accounts, but GMail is a little "quirky".  Send a (blank) email to shadow-gmail@saildocs.com  for the recommended settings (or see www.saildocs.com/shadow-gmail).   The great things about Gmail are that it is free, you get lots of space, and good search tools for archived email.   As described in the application note, use the "recent:" prefix on your login name, in conjunction with selecting the "all" selection in GMail's POP settings,  to give Shadowmail access to all recent messages.

I'm VERY knowledgeable about Internet protocols.  Give be a brief summary of ALL of the ways that I can retrieve my SailMail and email from my other accounts, from the Internet or over radio.  I'm aware that if I don't understand the terminology, you don't have the time to teach me what all this means.  If I'm not quite as knowledgeable as I thought and I don't understand your answer I promise to not email sysop for clarifications; I will instead find a knowledgeable teenager to explain it to me.
OK, you asked for it, but you promised to not send questions about this stuff.  A knowledgeable teenager can explain this stuff to you far more easily than we can via email.

By far the easiest way to retrieve your SailMail messages is to connect your boat computer to the internet ( via Iridium, Inmarsat, WiFi, Globalstar, Thuraya, DSL, cablemodem, GSM, EVDO, a Ethernet cable at work, or whatever...)  Then click the "internet" button in the message index window (lightning bolt), and then press the "connect" button (green ball).  This assumes that you are using a version of AirMail that is 3.3.069 or later.  For you engineers, AirMail is telneting into the SailMail system when you do this.  If you need more detail on how to do this send a blank email to internet@saildocs.com

If you HAVE to use somebody else's computer to read your SailMail messages when ashore, then go to SailMail's Webmail page and follow the instructions there to read your SailMail messages.  The disadvantage of this approach is that your messages don't end up in your mail folders on your PC, but it is nice that it works from any PC, anywhere.

Another way to retrieve your SailMail messages if you cannot connect your own computer to the internet is to use SailMail's POP3 server via some other computer.  You can set up a normal email client program (e.g. Outlook) to access SailMail's POP3 and SMTP servers.  Alternately you can set up an email account at GMAIL or Yahoo to "Pop" the messages from your SailMail account.  To get details on how to do this send a blank email to pop3@saildocs.com    One disadvantage of this approach is your SailMail messages will end up in other mail client folders, instead of in your AirMail folders.

You can set up your AirMail program on your computer to send and retrieve messages via POP3/SMTP  from any other non-SailMail email account that you might have.  This obviously requires that your computer has access to the internet.  To get details on how to do this, send a blank email to AirMailPOP3client@saildocs.com 

You can use the SailMail system to pop some other (non-SailMail) email account VIA RADIO through the SailMail system.  To get details on how to do this send a blank email to shadowinfo@saildocs.com 

The AirMail software can implement its own pop3 and smtp SERVERS so that other computers on your boat's own network can get their own copies of your SailMail messages via a normal email client like Outlook or via that computer's own copy of AirMail using AirMail's pop3/smtp client.   To do this, enable the POP/SMTP Server module and then set it up.  If you got this far in this particular FAQ, you no doubt can figure out how to set it up.

Remember, you said that you were an internet geek so you don't get to ask us to explain this stuff.  If you DO understand all of this stuff, and you find bugs or have suggestions then send your comments along to sysop@sailmail.com

How can I tell if I have RF interference getting into the audio line between my SSB and Pactor-modem?
One test for RF getting into your audio signal is to vary the FSK audio level while transmitting FSK, and watch the output power. It should increase smoothly as you increase the PTC-II's audio output from zero. Open airmail's terminal window, select Control/Set PTC-II amplitude, and move the amplitude tool so that it will not be covered up by the terminal window. Then pick a dead SailMail frequency (i.e. 18 megs late at night, or 5 megs in the afternoon) and select Control/Xmit Unproto, this will send a continuous FSK signal. On the amplitude tool, set the FSK level to zero and slowly increase it, watching the RF power output (with a RF wattmeter or by monitoring DC amps being pulled by the radio).   The watts (or DC amps) should smoothly change proportionally to your drive level.  If the power suddenly jumps from a low level to 100 watts then you've got troubles.

If you fail this test, you need better shielding and more ferrite on the wires interconnecting your Pactor-modem, SSB, and tuner.  Reread the suggestions regarding ferrite chokes under, "Installation Basics."  If you have not already fitted a ferrite line isolator at the tuner, then do so before proceeding further. It is not a cure-all, especially if your ground is less than ideal, but it is cheap insurance.  If you cannot say with confidence that your ground is solid, then do some more work there.

When I'm trying to connect to a SailMail station and therefore transmitting, the cursor on my Laptop bounces around and sometimes the Laptop hangs.  What should I do?
This is caused by radio frequency interference (RFI) getting from your SSB into your laptop.  Check the ground connections from your tuner to your ground, and clean and tighten them.  Add ferrites to all of the wires attached to your laptop, SCS modem, and SSB.

I occasionally get an error message while attempting to connect : "Communications with the PTC-II have been lost (modem-ready signal has gone false, power may be off. Terminal window will be closed."  What should I do?
Similarly to the above question, this is caused by your own transmit signal getting back into the computer, and scrambling the USB or serial interface to your pactor modem. This is a serious problem which must be addressed. It may be exacerbated by a change of USB port, but the cause is RF radio signal where it doesn't belong. See Airmail help for "RF interference" for info. In short, make sure your ground connections to the tuner are adequate and in good shape, surface corrosion of the copper foil won't hurt but corroded connections are a problem. Also check the antenna connections, from tuner to backstay. It is recommended to disassemble, clean and check all of those connections annually (e.g. when hauled).  Then check the ferrites on the cables from radio to modem, and computer. There should be a clip-on ferrite on each end of the two cables from modem to radio, and the USB cable from computer to modem. For the USB cable it is often necessary to use a larger ferrite (with a 0.4" hole) clipped around a loop of 3-4 turns of USB cable in order to completely block the RF.  Also we recommend a ferrite line isolator in the coax connection between radio and tuner, at the tuner end. This is supplied by some dealers, and is excellent insurance against RF.

How can I import my contacts from another email program into AirMail?
You should be able to export your contacts from your other email program or account into a csv file.  Save this file to a place you can find it on your PC. Then open Airmail and go to the Tools: Address Book: Import Addresses menu. Click on the "Browse" button and navigate to where you saved the contact (CSV file from step above).  Click on the "Load" button to open this file and display the contacts.  Put a check-mark to the left of the contacts you want to import and then click on the "Import" button on the lower-right.

I noticed that the propagation program needs data on Solar Flux to work.  Is there a means to retrieve solar flux or sunspot numbers to put into the propagation program?
The solar-flux index is sent whenever you connect to a station and Airmail updates it automatically. It is a line that looks like "{SFI = 69 on 2008/11/14 00:07z}" when you first connect.

I have my Pactor modem connected to a serial to ethernet adapter.  Can AirMail directly connect to the UDP or TCP port supplied by that adapter?
My GPS has a ethernet connection and provides NMEA data to a UDP port.  Can AirMail directly accept GPS NMEA data from a UDP port?
I have an SCS PTC-IInet.  How do I connect to it over the lan?
Airmail supports UDP and TCP connections, for dumb-terminal as well as the modem connections (useful for Lantronics serial-to-ethernet device-servers for example).  For a connection to a UDP server on port 3001 on the local network for example, enter "3001" as the com-port. Dumb-term will show "" in the status bar. The 255-address is the "broadcast" address, works anywhere on the local net.  For a TCP connection enter the IP address, a colon, then a "T" followed by the port# for example for a connection to a TCP server at on port 1001.  This syntax works either in Airmail's options window for modems (inherited by Dumb-terminal) or in Airmail's pos-report data-input window. From the data-input window there is a "show log" checkbox which shows all NMEA input in a text window. There is also "freeze" box to allow copy/paste, and a "capture" check which will save the data in a file.

If you have an SCS PTC-IInet connected to your PC over ethernet, if you select "PTC-IInet" as a modem type, then Airmail will try to find it on the network (it sends a query via a UDP broadcast packet, which the IInet responds to with its ID and tcp/ip address).

My propagation program has started acting incorrectly?
There is a known issue with Airmail that if you start and then stop Airmail then it may scramble the cached propagation file. It will fix itself when the lat-lon or SFI changes, but you can force an update by closing Airmail, deleting the "propcache.txt" file from the Airmail folder (under ProgramData for Vista, Program Files for XP), then restart Airmail.

When receiving grib files, sometimes I can not open them and I get a message: "floating point division by zero"
This is caused by trying to open a grib file that is too small, i.e. contains only a single lat or lon point. Viewfax crashes trying to scale the map, the problem is that a single point cannot be scaled. Try a slightly larger area and make sure it includes at least two rows or columns of data.  The other option, if all you want is a very small area, is to request a (text) "spot-forecast". You can do this from Airmail's grib-request window. Click on the button that looks like a "target" and position that target over the spot you are interested in, then click on the request button. You can also send a (blank) email to: spotforecasts@saildocs.com for more info.

How can I receive SITOR and NAVTEX text weather forecasts using my SSB and my Pactor-modem?
The USCG transmits weather forecasts in text using SITOR FEC transmission format, which can be received by any Pactor-modem that can be used for SailMail.  Their broadcast schedules are available on the internet .   The   USCG/NOAA schedule is at http://www.nws.noaa.gov/om/marine/hfsitor.htm      Some other countries also transmit weather forecasts via SITOR, and many countries transmit weather forecasts via NAVTEX.

The easiest way to receive these SITOR  text weather forecasts is to use the wxfax software that is available for free from the download page on this SailMail website.  It includes a handy way to receive SITOR, NAVTEX, and even CW broadcasts.

The advantage of receiving weather forecasts via SITOR or NAVTEX is that you will not use any of your SailMail connect time.

What is NAVTEX and how do I receive it?
Navtex comprises a network of stations transmitting weather data throughout the world, using the SITOR FEC protocol, on 518 kHz.  Because of the network of VHF voice weather stations in the USA, Navtex receivers are not nearly as common on recreational vessels in the USA as they are in other regions of the world.

If you want to use Navtex, the best option is to buy a dedicated Navtex receiverThey are not cheap, a few hundred bucks, but do a much better job than your SSB radio can. You can also copy Navtex with your SSB radio and pactor-modem, the problem is that marine (and ham) SSB radios are optimized for the 2-30MHz range and are not very sensitive at the 518 KHz frequency used by Navtex-- which means a pretty short range with Navtex.

It doesn't cost anything to try however. Use Airmail's Getfax companion, select "Fax/Navtex" mode, in the station-box select NAVTEX and 518 for the frequency. (If you set the radio manually then set the radio to USB mode, 516.5 KHz). Leave it running, and it will copy whatever Navtex transmissions come along.   Most stations transmit every 30-60 min's.

Can I get ViewFax to display weather data that I've received in IAC Fleet Code.
No.   Viewfax displays grib files, but not the numerically-coded fleet codes (e.g. Nadi tropical chart).   You will need an IAC fleet-code viewer.  There is a program on the Pangolin website called "PhysPlot", see this website:

Also there is some info here:
For background for casual readers, "Fleet Code" is a method of encoding atmospheric pressure in groups of 5 digits that has been in use since before WWII.  Those numeric codes were traditionally transmitted in morse code and the pressure maps were drawn by hand by connecting the dots. The morse code transmissions ended for most regions of the world in the early 80's.  The Nadi tropical chart is still sent in Fleet Code, and is available by email in that format.  There may be others around the world as well still using Fleet Code.

Can I insert any of the NMEA data that AirMail reads into the "custom" position reports?
Mostly yes.  In Airmail's pos-reports window, "custom" tab, click "setup". Then Right-click in the message area, and you will see a list of what codes can be pasted into your message. Paste a few, then select "preview" to see the format.  Here are the available codes:

6:53 PM

6/12/2014 and 6:53 PM are UTC, there are also undocumented codes for 11:53 AM and 6/12/2014-- your local time, not the recipient's.   The same codes work in the "footer" tab.


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Application Notes


Here are some application notes that you can either browse to from here or you can request to be sent to you via email.  To request that a copy of any of the application notes below be sent to you via email just put the title of the application note in the email address followed by "@saildocs.com"   and send a blank email.

For example if you want to get a copy of the application note on IridiumPPP sent to you, just send a blank email to:   IridiumPPP@saildocs.com


Bipolarhow to set up AirMail for use on both Ham and SailMail networks
comports info on comports on PC's for AirMail
IridiumPPP setting up an Iridium PPP connection
ipad using SailMail via an iPad or iPhone
internet Accessing SailMail via the internet using AirMail
IsatPhone How to use the Inmarsat isatPhone
stations SailMail stations update
firewall nits to get Win 7 to work with an iSatphone
pop3 Accessing SailMail messages via SM's pop3 server using some other mail client (e.g. Outlook)
relayinfo Relaying group messages
relayinfo2 more information on Relaying group messages
rxhelp troubleshooting slow receive speeds
security computer security
seminars seminars on how to join the SailMail Association, install the gear, and use the system
serialports information on how to add serial ports to a laptop
shadowinfo using SailMail to read messages from some other pop3 account
shadow-gmail using SailMail to read messages from a Gmail account
spam avoiding spam
txhelp troubleshooting slow transmit speeds
usb drivers usb drivers for the PTC-II usb
usbtroubles troubleshooting usb problems
Vista Running AirMail under Windows Vista





We are collecting additional application notes for specific  computers, radios, and Pactor-modem's.   If your equipment is listed here, you might find the note helpful.  Please send any suggestions that you might have to improve the application note to sysop@sailmail.com .

If your radio/Pactor-modem combination is not listed here, but you have successfully sorted it out and are feeling charitable, please write an application note and send it for inclusion here, to sysop@sailmail.com.

Application Notes:

Iridium GO!

Grounding Tips

Installation Checklist for Professional Installations

Setting Drive Levels on your Pactor-modem

How to detect and fix Radio Frequency Interference problems with your Radio/Pactor-modem installation

How to use AirMail on Apple/Mac Computers

Observations on different SSB's for use with SailMail

Overview on the use of Icom Marine Transceivers with SCS PTC-II* modems

Details on using an Icom M802 with an SCS PTC-IIpro

Details on using an Icom M710 or M700pro with an SCS PTC-IIpro

Controlling an Icom M710 or M700Pro via a com port

SEA 235 Radio

SGC SG-2000 Radio

Furuno Radios

Kenwood TKM-707 Radio

Skanti TRP-8250 Radio

Setting the Baud Rate or Initializing an HF Modem

Using a Kielradio modem on the SailMail system


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AFSKAudio Frequency Shift Keying, also known as AFS, and J2B.  In this modulation method, an audio signal is sent from the  Pactor-modem to the radio and modulates the radio just as if USB had been used.  The main difference is the standard for displaying and listing the frequency.  When using USB, the carrier frequency is displayed by the radio.  When using AFSK, the center frequency of the modulated signal is displayed by the radio.  The SCS PTC-II must use either AFSK or USB modulation, and the KAM+ works fine using AFSK or USB modulation.
AmtorAmateur Teleprinting Over Radio, the first popular ham-radio digital communication protocol which included direct linking between two stations with data acknowledgement and error checking. It is the same mode as commercial Sitor, and has largely been replaced by Pactor on the ham bands. 
ARQAutomatic Repeat reQuest, is the term used to describe protocols in which the receiving equipment can request repeats of data that it has missed or received with errors.  Amtor, Sitor, Pactor (I & II), and Clover all have this capability.
CloverA higher-speed HF protocol developed by HAL communications, utilizing multiple-tone phase-shift encoding. Effective throughputs are similar to Pactor-II, and it will be long debated which is the better protocol although Pactor-II has won the popularity contest.
DSPDigital Signal Processor, a specialized microprocessor for processing analog signals. Signals are converted to digital form and processed using various mathematical transformations before being converted back to analog form if required for output. 
FEC SITORForward Error Correction, a variation of the Sitor/Amtor protocol which is ideally suited for the broadcasting of text files to multiple recipients simultaneously.  The protocol incorporates redundant data, so that reasonable numbers of errors can be corrected at the receiving end.  The FEC protocol does not allow the receiving end equipment to request a repeat, as do the ARQ variants of transmission protocols.  FEC Sitor is still used for the transmission of text weather forecasts by the USCG/NOAA, other governments, and by commercial radio networks.
FSKFrequency Shift Keying, also known as F1B.  A simple method of sending digital information over radio, where a binary "1" is assigned one tone and a "0" a second tone. These tones are called "Mark" and "Space" after RTTY practice, and are typically separated by 170-200 Hertz on the HF bands.  FSK or F1B implies that the radio gets digital data from the Pactor-modem, whereas AFSK (or AFS or J2B) implies that the radio gets audio frequency tones from the Pactor-modem.  FSK (F1B) is not usable with the SCS PTC-II Pactor-modem because the PTC-II uses phase shift keying (in Pactor-II mode).  Strictly speaking, it is possible to set up the KAM+ to use FSK (F1B) on some radios, but there is no advantage over the AFSK (J2B) or USB (J3E) approach.  
J3EUpper Sideband modulation, also known as USB.   This is the mode used for voice over a marine SSB transceiver.  This mode can also be used for SailMail, but the "carrier" frequency must be calculated and entered into the transceiver.  Details are in this primer.
KAM+A popular multi-mode TNC/Pactor-modem manufactured by Kantronics. The current model is the KAM-plus (KAM+), and an enhancement board can be added to older KAM's to make them KAM-E's with the same functionality. The KAM includes all the basic digital modes plus Pactor.  The KAM also includes G-TOR, a proprietary 300-baud protocol, which at this time is not used by SailMail.
 PactorPactor A digital radio protocol developed by a group of German hams in the early 80's, allowing faster and more reliable communications than Amtor. The name comes from Latin for the "Mediator". Pactor operates at 100 or 200 baud depending on conditions, with net throughput of up to 18 characters per second.
Pactor-IIA improved version of the original Pactor protocol, also designed by SCS, the same group that did the original Pactor protocol. Pactor-II is a two-tone phase-shift system (PSK), that uses a 350 Hz radio bandwidth and operates at basic rates from 100-800 bps depending on conditions. Net throughput including the effects of compression is up to 140 characters per second depending on conditions.
Pactor-III A dramatically improved version of Pactor, also designed by SCS.  Pactor-III uses PSK on up to 18 tones, across a 2.4 kHz bandwidth to transfer up to 5000 bps.  Pactor-III transfers data 3-5x faster than Pactor-II in good conditions, and slightly faster than Pactor-II in weak signal conditions.
PSKPhase-shift keying, the encoding method used by Pactor-II.  Encoding data into multiple phases for each tone, and transmitting both tones at once, allows more information to be telemetered.
PTC-IIThe Pactor-II HF modem from SCS, a powerful DSP-based HF modem that also supports all of the basic digital modes (including gray-scale weather fax).
RTFMRead The "Fine" Manual.  This is the solution for many problems with the AirMail software or with the SailMail service.   Please do this before emailing the sysop.
RTTYRadio Teletype. Originally designed for electro-mechanical teleprinters, RTTY generally uses a 5-bit Baudot code and operates around 45 baud. There is no acknowledgement (except from the operator at the other end) and no error checking.
SCS PTC-IIThe Pactor-II HF modem from SCS, a powerful DSP-based HF modem that also supports all of the basic digital modes (including gray-scale weather fax).
P4dragon DR-7800 The latest Pactor-modem from SCS.  This modems provides the fastest data rate of any of the SCS modems for those members willing to pay the extra cost.
SITORSimplex Teleprinting Over Radio.  The original improvement over RTTY that was developed for marine use.  SITOR incorporates error detection and correction.  This standard uses the Baudot codes (5 bits per character) and so limits messages to all caps.  This system is still in use by commercial marine service providers and is supported by both the SCS PTC-II and KAM+ Pactor-modem's.
TNCTerminal Node Controller.  This term is sometimes used to describe the Pactor-modem's used for SailMail (e.g. the SCS PTC-II).   This term is more accurately used, however, to describe the controllers used for VHF Packet radio, which is a short-range digital communications technique that is commonly used by ham radio operators.  Some TNC's include Pactor-modem capability, but not all.
USBUpper Sideband modulation, also known as J3E.   This is the mode used for voice over a marine SSB transceiver.  This mode can also be used for SailMail, but the "carrier" frequency must be calculated and entered into the transceiver.  Details are in this primer.


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Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 by Jim Corenman and Stan Honey