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Using the Icom M803 with Sailmail

Icom’s new M803 Marine SSB Radio began shipping in early 2020 and is a terrific radio for use with Sailmail. It supports the latest DSC standard, incorporates Icom’s latest SDR radio designs, and also includes GPS (internal or external) and provides that data for position reporting. Any of the SCS modems are supported.

Connection is similar to Icom’s previous marine radios, with audio and control cables commecting radio to modem: One for the audio signals and a second cable for radio frequency control. While the M803 has the same “ACC” connector as the earlier M802 and M710/700pro radios, it is not compatible and a different cable is needed for the AF/MOD connector. Here are the details:

Modems: Any of the SCS Pactor modems including the DR-7400 or DR-7800 Pactor-4 modems, the PTC-IIIusb Pactor-2 modem, and any of the earlier PTC-II modem-series.

Cables: The audio cable is Farallon #9098 (2M, or 9099 for 4M). This is a new cable for the M803 (details below). Connect this from the modem’s “Audio” (“Main Audio” for the DR-7800) to the radio’s “AF/MOD” connector and plug the 8-pin DIN plug into the radio’s “ACC” connector (for 12V power).  The 9090 cable used on most Icom radios for the “ACC” connector cannot be used. The audio level settings should be 900/1200 for FSK/PSK respectively. Airmail’s “autoset” function has been updated and works well for the M803.

Frequency Control: The radio’s “REMOTE” frequency-control connection is via a standard RS232 serial port and can be connected to the modem with a Farallon #8083 cable (2M, or 8084 for 4M). Connect this from the modems “Control” connector to the radio’s “REMOTE” connector. Alternately use a standard serial cable from a computer serial port (or USB/serial adapter) to the radio’s REMOTE port (9-pin male-female). The M803’s Remote-ID is 20, and the baud rate is 4800 (avoid the higher rates).

Ferrites: It is important (with any radio installation!) that ferrite chokes be installed at each end of both cables from the modem to radio, and also at both ends of the USB cable from computer to modem (does not apply with a bluetooth connection). The ferrites should be located near each end, use a small cable-tie to prevent them from sliding down the cable. It is also a good idea to add a cable-tie around the ferrite itself to make sure it stays closed. The recommended ferrites are Type-31 material from Fair-Rite.

Modem setup: The only setup required is for a PTC-IIIusb/DR-7400/DR-7800, if you want it to power-on with the radio (and of course you do): Set Dip Switch #1 on the back of the modem to the DOWN position to power on automatically when the radio is powered on. 

Radio settings: Check the following settings in the radio’s setup menu. To change a setting press the radio’s MENU button , then use the arrows or the big knob select the setting and press the “enter” (ENT) key, then repeat for each sub-menu:

  • MENU > Configuration > Remote > Interface: Select RS-232C. Leave baud rate set to 4800 bps. Verify that MOD is set to AF/MOD.
  • MENU > Configuration > GPS > Internal GPS: Verify GPS, GLONASS and SBAS are set to On if using the external GPS antenna (see below).  
  • MENU > Configuration > GPS > External GPS: If an external GPS is connected via the BNC connector then verify the baud rate: 4800 for most connected GPS receivers, 38400 for a connected AIS receiver.
  • MENU > Radio Settings > Auto Tune: Select ON (assuming the AT-140 Icom auto-tuner is used). 

Other notes: The M803 has a Noise Reduction feature (under Radio Settings menu), it is recommended to leave this off for radio email– the modem has its own digital signal processing. Similarly leave the NB Level (noise-blanker) setting at minimum, and leave the RF-Gain setting set to max (9). Also use high TX-power mode (soft-key menu)– reducing transmit power will slow the connection.

Position Reporting: The M803 needs to be connected to a GPS in order for the DSC distress function to work– either using the radio’s internal GPS with a connected antenna, or (same as the M802) via the GPS-Data BNC connector from an external GPS. Where the M802 kept this data to itself, the M803 transmits the GPS data (from either source) via the REMOTE connector to the computer where Airmail (ver 3.5.054 or later) will pick it up.

What this means is that once GPS is connected to the radio for DSC, Airmail can update your lat-lon whenever Terminal window is opened, and Position Reports are updated automatically. Multiple formats are available including MarineTraffic to continue your AIS track offshore, CruisersCafe for Yotreps-style updates, and Sailblogs for a comprehensive tracking/blogging site.

 

Glossary of SCS Pactor Modem model numbers

SCS model numbers and pactor modes are confusing.   Current modems in production are the PTC-IIIusb and the P4dragon, and are recommended.    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 somewhat faster still, particularly with strong signals.  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 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.

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.

SCS Pactor Modem Guide
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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.

Explanations:

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#.