Micro APRS Station

Thanks to the latest hardware from Kenwood, Garmin, Delorme, 3Com and Mike Musick's Palm III adaptation of Bob Bruninga's world famous APRS called pocketAPRS, mobile APRS ops have never been easier or more compact. Just the Palm III and the TH D7A are a complete packet station due to the TH D7A's self contained TNC. Add a GPS receiver like the GPS 35* or Tripmate, a 12 VDC battery, and pocket APRS and you are ready to go portable complete with moving map.

Late breaking news 1-22-99 Mike Musick/N0QBF author of pocketAPRS makes this welcome observation about the latest Beta version of pocketAPRS. "This is the exact "jump kit" we're taking on our trip. I finished the wiring harness last night, plugged it in, and waddayaknow, the $GPRMC sentence was coming through the D7 just dandy. Apparently the NMEA parser problem in the D7 only affects generation of its own posit beacon. As others have reported, I did confirm that this configuration minus the Palm sent 00/00 posit reports. The "GPSTEXT" TNC command seems to operate independently of the APRS engine within the D7, thank goodness. This is good news to everyone who wants to operate the D7 with a computer and "just any" GPS."

In this picture are the Rand McNally GPS RX, Kenwood THD7a, Serial cables and 3Com PalmPilot III

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Here is some info to help you wire up the PalmPilot III to your TH D7A. I found this pin out very helpful.

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I am using the serial adapter cable available from Delorme and the Mouser cable with the 3 conductor 2.5 mm right angle plug.The pin outs, as well as all the resources I used are below :

3 conductor plug to TH D7A

Sleeve = gnd

ring = red

tip = wht

DB-9 (female)

Pin 2 = wht

Pin 3 = red

Pin 5 = gnd

PIII I/O edge connector

pin 3 = tip = wht = RD

pin 5 = ring = red = TD

pin 10 = sleeve = gnd = SG (sig gnd)

In lieu of a cable from Delorme, you may adapt a 3COM PalmPilot III Hot Link cable (available from Staples for about $25.00 or so),

Mike Musick's pocketAPRS website

Garmin GPS 35

Kenwood TH D7A

Mouser Electronics (800-346-6873) 3 conductor, 2.5 mm plug, 72", cord set, P/N 172-2010

Delorme Palm Interface Adapter cable

3Com PalmPilot III.

pocketAPRS latest Beta version

PalmIII serial cable pin out.

PalmIII pin description

*The GPS 35 is only compatible with the TH D7A "APRS stand alone tracker" mode if it has had the Kenwood firmware upgrade. See the TH D7A/GPS compatibility page for the latest news.