[OZAPRS] Home brew HF APRS transmitter - follow up
lists at rumpleteazer.net
Tue Aug 2 16:32:07 EST 2011
A follow up from my earlier posts re a home brewed HF APRS transmitter.
The CCI based driver amp sacrified itself over the weekend, most likely
because I had the corner pegging set a bit to quickly in the Tracker2.
End result was a buggered final transistor and a few open circuit
Having only a few days before I head off into the bush, I stripped a
Codan 8525A, leaving the front panel and PA. I mounted the PSK31 based
transmitter in the empty space, wired it up the very ruggedly built
Codan PA, hardwired the LPF to the correct range, gave it 12V and
voila. I now have a 100W APRS transmitter. Sits nicely under the
I have backed off the smart beaconing so that beacons go out at 2 min
intervals at 100km/h, 30mins when stationary, and set the beacons to
compressed. Hopefully I won't be hogging the frequency so much now
The Tracker2 has a nice feature to not transmit under a configured
voltage. I've set mine to not transmit until the voltage gets to 13.2V,
which should be only when the engine is running and charging the
Got some pretty good results on the short drive to work today, proof in
the pudding will be my trip to the Flinder's Ranges and Lake Eyre
starting next week.
If anybody wants any details, feel free to shoot me a note.
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