Category Archives: Pactor/SSB installation

How to install and set up a Pactor modem with a SSB

Setup Pactor modem and SSB, overview

To send and receive email over the SailMail’s worldwide network of SSB stations, you need a properly installed SSB and you will need to acquire an SCS Pactor modem, which is a special modem available from ham radio or marine electronics dealers that is designed to transfer data over radio.   The SailMail system works best with the SCS PTC-IIIusb or a P4dragon modem, with the P4 modem providing somewhat faster data communications.   The SailMail system will also work with older design SCS Pactor modems, such as the II, IIe, IIex, IIpro, IIusb, but if you own or buy an older SCS modem, make sure that it is upgraded to use the Pactor-III mode, and that you install your modem in such a way that AirMail can control the frequency of your SSB. DR7800%20400x400

Once you buy your Pactor-modem, there is still much to do:  you will need hook up the Pactor-modem with your radio and Windows based laptop, download the AirMail software, set it up, and learn how to operate the system.   This can be tricky unless you get help.

You have two choices:

You can buy the Pactor-modem yourself, figure out and make the interface cables, download the software, read the documentation, and sort it all out.  If you want to take this approach, there are instructions on this website.    Alternatively…   you can get help from your marine electronics dealer who will sell you the Pactor-modem, supply the professionally wired cables to connect it to your radio, hook it up, load the AirMail software in your laptop, and show you how to operate it.  The radio-specific cables with ferrites etc. and installation will typically cost about $200-300.    Even if you take this approach, you should download and keep a copy of this website aboard as a reference.
Unless you either like sorting out details of interfacing laptops and radios, or you are bored to tears and looking for a challenge, we suggest that you contact your marine electronics dealer.  ic-m802_02251405

There are a number of marine electronics dealers who can sell and install a Pactor-modem for you, located throughout the world.  They will obviously charge you for their services to do the installation, but they are earning their money; the installation requires skill.  There is a list of these dealers on this website.

Connecting via SSB

With AirMail open, go to the terminal window by pressing the button with the blue globe in it.     Check that your “clarifier” on your SSB is centered.  Check all of the frequencies by scrolling through the stations and frequencies in the pull down menus.  Your radio should be remotely tuned by the PC/modem to a frequency that is 1.5 kHz below the frequency that you select via AirMail, if you hear a periodic “chip, chirp” or a periodic “rasping” sound at 2-4 second intervals, that’s somebody else using that 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 another.  Check 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 “ “.  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  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.


Installing and Setting-Up the AirMail Software

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 make sure that the Comm Port is correct. In the Radio Connection section select the appropriate option for the remote control of your radio. In the Audio Tones section the Center Frequency should be “1500” and a dot should be next to USB.  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.

Assuming that you have connected your radio for remote-control, the frequency selection in the right menu will adjust the frequency on your radio.

Equipment choice and installation 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 (with tuner, antenna, and grounding system), 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 audio in/out signals, a PTT (push-to-talk) signal to tell the radio when to transmit, and a remote control wire to allow your PC to tune the radio via the modem.



Transmitting and receiving digital signals is similar to voice, and most modern marine SSB radios will do the job.

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 like the Icom M802.


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 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.


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.


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 to 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 website.

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.

The GAM antenna and KISS-SSB counterpoise are very convenient and do work, but using either or both of them will increase the amount of RF radiation inside your boat.  The GAM antenna couples RF energy to your entire rig, not just the backstay.  The KISS-SSB counterpoise radiates RF inside your boat.  If you use either of these then plan on the increased need for ferrites to keep the RF out of your laptop, modem, and other sensitive electronics such as your autopilot and wind instruments.


Using AirMail with both SailMail and Winlink

The same copy of Airmail can can be used to access both the SailMail system and the ham radio stations.

The SailMail Association is a non-profit association of yacht owners that operates and maintains a network of private coast stations in the Maritime Mobile Radio Service. Sailmail provides low-cost email service to its membership, which is limited to recreational vessels. Users must be registered, details and registration information are available from The advantage for hams is that Sailmail has no restrictions on third-party traffic or business-related messages. The stations are also in different places which might provide easier access from some locations.

In order to activate the Sailmail mode for Airmail you need to copy a system definition file (System.Sailmail.ini) to the airmail folder. This is normally done by the same download that brought you this note. (Alternately, send a blank message to:
When you restart Airmail it reads the definition file and makes the appropriate changes to airmail.ini to add a system called “Sailmail” in addition to “Ham”.

Connecting to Sailmail:
In order to handle other stations such as Sailmail, a new level of control was created called “System”. Logically speaking, each system includes a set of stations, and each station includes a set of frequencies. Airmail (as downloaded from the Airmail site) comes configured for the “Ham” system alone.

When a second system is defined then a new pull-down box appears to the left of the “Station” box in the Terminal Window, for “System” – HAM, SAILMAIL, etc. When you choose a system it will remember the previous station and frequency and set the appropriate mode if required.

So first select the appropriate system, then the station and (if the remote frequency interface is connected) then choose a frequency. To connect click the green “Connect” button (or use the F5 key), exactly as before.

Posting outgoing messages
Sending messages to a ham station is done in the same way as before, by posting to the station’s callsign (or multiple callsigns). A message can also be posted “WL2K” for any Winlink-2000 station, or to “Ham” to send it to any connected ham station. There should be a default entry in your Auto-post list (Tools/Options, Routing Tab) that says “Default=Sailmail” or “Default=WL2K” or whatever, if it is not there then add it. This will cause any message to be automatically posted to that system, unless specified otherwise in the Address Book or Message Header “Via” box. You can always change the posting with the File/Change Posting menu (or by right-clicking the message in the message index).

Messages to Sailmail are addressed to the gateway name “EMAIL” rather than “NEXUS”, but Airmail will take care of this automatically. Messages for Sailmail should be posted to the system name “SAILMAIL” rather than the station callsign. Messages posted to “Sailmail” will be sent to any Sailmail station which is connected to. So an address book entry for a message which should always go via Sailmail would specify “Sailmail” in the Via box.

Be sure to add a “” entry to your address book as above, that is how you send a note to the Sailmail support folks in case of any difficulties or questions. And for membership questions, send a note to:

Frequencies used by SailMail stations

Nearly all members set up AirMail to remotely control their SSB, so they don’t need to set the frequencies themselves.  But if you need to tune your radio yourself, you can download the frequencies supported by each station at:
The frequencies in the “stations” document are the center-frequencies.  If you tune your radio yourself, set it to a carrier or dial frequency that is 1.5 kHz below the  frequency in the table.  For example 10343 kHz is one of the frequencies listed for the Watsonville station.  To use this frequency your radio must be tuned to a carrier frequency of 10341.5 kHz.  AirMail will do this subtraction for you and you will see the frequency to set your radio to displayed along the bottom of your terminal window.  Nearly all members interface their radio for remote control so AirMail sets the radio for you.

If you want your AirMail software onboard to automatically updates its list of station frequencies, then send an email to   When you receive the response via AirMail, AirMail will update its database.