[aprssig] APRS trackers on 10m

Robert Bruninga bruninga at usna.edu
Sat Nov 26 09:05:38 EST 2005


Actually, here would be my approach for new low
cost APRS trackers for Amateur Radio:

1) Xtal controlled 25W tracker on 28.xxx
2) Operates straight FSK at 1200 baud 1000 Hz shift
3) uses trimed down CB antennas for cheap mobiles
4) XTAL controled RX can be built with just an RF
    amp and an FSK receiver chip

The 28.xxx would be one of the channels set aside
for AX.25 packet?  ANyone remember any?
I think we can do 1200 baud there...  and using FSK
we only use up 3 KHz of bandwidth, and not 20 KHz!

The beauty is:
0) A GREAT club project
1) the LOW COST. (with a built-in tiny-trak)
2) new band would avoid 2m QRM to APRS mobiles
3) The alternate input band would avoid collisions
4) low frequency wouild make design/tuning easy
    and parts simple
5) 25W should be easy to do with one transistor
    at the low 3% dutycycle...
6) Black box with only 12v, GPS and Antenna connector

Would be GREAT for local coverage...
Would be FUN when 10m comes back!
de WB4APR, Bob





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