Overview on the use of Icom Marine Transceivers used with any version SCS PTC-II* modems:

 

There are specific recommendations and information within the help files in the AirMail software.

The Icom M710, M700pro and M802 transceivers are fully digital capable and are excellent choices for use with Pactor. They also offer a remote-control input that can easily be used for remote frequency setting with AirMail. The M710 and M700pro models both share the same chassis and RF sections and are quite robust, and are capable of transmitting full power indefinitely. The difference between the M710 and M700pro is with the front-panel control layout- the M700pro is marginally easier for general ham use, although no marine radio is particularly convenient for hopping around on the ham bands. (The FCC rules for marine type-acceptance prohibit most of the controls which hams find useful). The new M802 has a remote control head with lots of features, and is quite easy to use for both marine and ham use.

(Of the earlier M700 and M800 radios, only certain models are capable of continuous full-power digital transmission and generally must be used at reduced power levels, consult the manual for details. This is less of a limitation for the PTC-II controller, because the average power for Pactor-2 is only about half the peak value due to their complex waveforms. The older M700 also did not incorporate a connector for external audio connections, and hooking up a modem requires modifying the radio).


Remote control for mode and frequency is available using either a TTL-level (0-5 volt) connection, or a RS232-compatible "REMOTE" connection, depending on model.
 

The Icom M710 (and M710RT) includes both a TTL-level (0-5 volt) "Clone" jack which can be used for remote control, as well as a RS232-compatible "REMOTE" NMEA connector. The TTL-level jack is a 1/8" mini-phone jack which can be directly connected to the "remote" connector on a PTC-II or PTC-IIpro modem, using a specially-wired cable (see the AirMail software help file on "Connecting a PTC-II to an Icom M710/M700pro Marine Transceiver")
 

The 9-pin "REMOTE" connector looks like a RS232 connector but is not wired the same, and requires a specially-wired cable to connect to a computer serial port or to the PTC-IIpro's "remote" connector.   For details see the help files within the AirMail software.

Some Icom M700pro have only the 1/8" Clone jack described above.  This can be connected directly to a PTC-II or IIpro as above, or a suitable level-shifter (e.g. Icom's OPC-478 cable- ) can be used for connection to a computer serial-port.

The M802 has a standard RS232 "REMOTE" 9-pin connector, which can be directly connected to a PTC-IIpro or a computer serial port.  Connection to a computer serial port may require adding another serial port using an USB/serial converter.   Connection to a PTC-II will require the SCS RS232 level-shifter.


Radio programming
Some models of the M710 and M700pro are only set up to transmit on marine frequency bands. These bands exclude all of the ham radio frequencies and most of the Sailmail marine frequencies, which are assigned for marine data use but are outside the traditional marine voice bands. The differences between the models are strictly a matter of the programming of the radio (except "GMDSS" models- see below). Programming (or "cloning") the radio is a simple matter given the special software and cable, and can be done by any Icom dealer. Most dealers will reprogram a radio that they have sold without charge, others charge for this. When purchasing a M710 or M700pro radio, be sure to specify "all-band transmit".

The M802 can be "opened up" for all-band transmit with a special key sequence: First urn off the radio, then press and hold the “2”, the “MODE” and the “TX” button, then (while holding these three buttons), turn on the radio.
GMDSS models

Icom also sells "GMDSS" models of the M710 in Europe and elsewhere (not in the US). These models do not include the standard Icom 8-pin DIN connector noted above, but external audio connections are available via a 9-pin "DB"-style connector. See the respective manuals for connections. There is also connection information at the Farallon website, www.farallon.us.

AirMail Help ©1997-2008 Jim Corenman