[aprssig] News from DCC (3) 10 mile 100 KBPS packet links for $10?

Robert Bruninga bruninga at usna.edu
Sat Sep 22 10:55:57 EDT 2012

If we can just figure out HOW we would use our UHF digital bandwidth,
I am still impressed with the 1" square data transceiver module that
only costs $12 or so and yet is:

Frequncy agile 300 to 900 MHz, can do 2k to 128k baud, with sensitiivy
within 3 dB of a typical ham radio and FSK/GMSK built in.  GOogle a
spec sheet (150 pages) for the RFM22 device.

If EVERY HAM (not just digital guys) but one of these in a pill box on
their tower it would seem that we could have quite a flexible RF local
MESH network.

Of course with only 50 milliwatts, to get the 10 mile range you need
LINE OF SIGHT. but, even in the field, imagine deploying a module
(digi) with 2 AAA cells about the size of a golf ball using a
slingshot and fishing line to the top of the nearest 100' tree.  It
would run for 24 hours and can be retrieved by just cutting the

With an RF turnaround of under 1 millisec, we are talking about a 2
order of magnitude improvement in throughput.

THe RF, modulation, chip and everyting else is trivial.  But what to
do with it needs our creative thinking.

We could stream LOTS Of ham radio content on dedicated or frequency
agile digital UHF channels.


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