Application Note for Icom M802

including use with PTC-IIpro Pactor-modem.

December 06, 2003

Wrinkles on early production radios:

Some early production Icom M802 radios had a couple of wrinkles that are worth watching out for.

1. The M802 is shipped with "auto-tuner" set to "off" by default. To enable the auto-tuner, turn the radio off, then hold down the "Mode" button and push the "power" button to turn the radio on. The display will say *** SET MODE *** across the top. Then rotate the left knob until "AUTO TUNE" is displayed, and use the right know to select "ON".
    
2. Some early production M802's  do not always successfully tune the antenna (in conjunction with the Icom AT130 or AT140 tuners).  After you press the "Tune" button, watch the "Tune" indicator to make sure that the tuner has successfully tuned the antenna.  Sometimes it says "Thru" after you press the "Tune" button and requires additional attempts until the radio indicates "Tune".  When you start transmitting (or hit the "tune" button) the tune-indicator should flash, and then stay on steady. If it flashes and goes out, or says "Thru", hit tune again. If you see this problem, then you will have to get your dealer to send your M802 radio back to Icom to get the firmware fixed.   Icom has confirmed that all of  their current inventory is modified to fix this problem, and all future production has been changed to avoid the problem.  Icom performs the modification to fix this problem on all radios that come in for service no matter why they came in.
   
    
3. Some early M802's exhibited low transmit power levels when transmitting voice.  A radio check with a friend or a test by a radio technician can easily detect this wrinkle.
    
4. Some M802's are shipped in a configuration in which they can only transmit on the traditional marine bands.  To be able to use every SailMail station, you may need to set your radio to be able to transmit on a wider set of marine frequencies.  Here are Icom's instructions on how to set the radio to the "open" configuration:
   1) Turn off the radio.
   2) Press and hold the “2”, the “MODE” and the “TX” button.
   3) While holding the three buttons, turn on the radio.
    

Now that Icom has the early problems sorted out, it appears that the M802 is a very nice radio and will work very well for SailMail.

If SailMail members have other observations regarding the M802, please send them along to sysop@sailmail.com .

Cable Configuration:

Notes:

1. Check the manuals for the Icom and the PTC-IIpro for the pin locations on the connectors!   They do not necessarily agree with the pin numbers of the connector that you might buy, depending on that connector's ancestry. The colors shown above are for the pigtail cable supplied with the PTC-IIpro. Check the colors with an ohmmeter, errors are possible.
2. The German-style DIN connector has a different physical pin geometry, and is not interchaneable with the US-style DIN connector used by Icom. Label the cable ends to avoid any confusion over which end goes where.
3. The PTC-IIpro has provision for an alternate 12V input on its HF audio connector. This provides a convenient way to connect power to the modem, but if the cable is particularly long then this could be a source of RF interference. Consider a separate power connection for long cables.
 

Remote control cable for M802 radio via AirMail and PTC-IIpro:. 

PTC-IIpro: Remote frequency-control is optional, but highly recommended when a PTC-IIpro modem is used with an Icom M802 transceiver. This connection uses the PTC-IIpro's RS232 remote connection to the radio's "REMOTE" jack (a standard RS232 connection).

Find the pigtail connector that came with your SCS PTC-IIpro that has the din connector that fits into the  "HF Transceiver Control" port on the back of the PTC-IIpro.  On the other end solder an 9 pin D connector as follows:

* A careful reader of the Icom M802 user manual will observe that the documentation is in error with respect to the direction of data flow on these pins in RS232 mode (oddly they are correctly labeled for NMEA mode).  The M802 service manual schematic is correct.   Use the above connections; they work.

Be careful to insulate the other wires coming out of the PTC-IIpro pigtail.  You can destroy your PTC-IIpro if they get shorted to one another or to ground.   Put a ferrite on both ends, as usual for all of your interconnect wires.

Plug this cable from the "HF Transceiver Control" jack on the PTC-IIpro to the "Remote" jack on the Icom M802. 

Direct COM-port connection:

The M-802's "REMOTE" connector is a standard 9-pin serial connector which can be directly connected to a computer serial port with a standard 9-pin male/female serial extension cable.   So if you have a SCS PTC-IIe or a PTC-II that does not have a RS232 output, you can directly control the M802 with another serial port on your computer.  This may require you to add another serial port using a USB/RS232 adapter.

Radio Settings:

The M802 is shipped with "auto-tuner" set to "off" by default. To enable the auto-tuner, turn the radio off, then hold down the "Mode" button and push the "power" button to turn the radio on. The display will say *** SET MODE *** across the top. Then rotate the left knob until "AUTO TUNE" is displayed, and use the right knob to select "ON".

NOTE: Some early M-802's had a problem with the auto-tune mode failing to tune properly. The symptom was that the "Tune" indicator flashed and then went off, rather than staying on steadily. The radio's "SWR" indicator would also flash while transmitting. This is now corrected, and radios which exhibit this problem can be returned to an Icom dealer for updating.

Follow the instructions that came with your radio, use the front-panel "Set Mode" function, and check that the Remote ID is 08, and the Remote IF is  NMEA.  These settings are the defaults, so if you haven't changed them before, they should be ok.

(You do not need to connect anything to the "AF/MOD" connector on your M802 radio; all necessary signals are taken care of by the cables that connect to the "ACC" and the "REMOTE" connectors as described above.)

AirMail Setup:

Under Tools/Options/Connection Tab, enter the following selections:

AirMail Options Settings:

Modem (TNC) connection:

Modem type: PTC-IIpro (or select appropriate model)
Comm port: COM1 or as appropriate
Baud rate: 38400 or 57600
Show link messages: no check

Audio Tones:

Center Frequency: 1500
Check "USB"
Amplitudes: as appropriate, start with 250/330 (see Setting Audio Levels)

Radio connection:

Check "Direct using PTC-II control port" (or "Direct via COM port")
RS-232: Checked (for PTC-IIpro only, important!)
Radio type: "Icom-M802"
Baud: 4800
Icom Addr (hex): 08 (must match radio's REMT-ID setting)
Dial offset: 00

AirMail Help ©1997-2008 Jim Corenman