[amsat-bb] Re: AO51 APRS @9600 Bps

Bob Bruninga bruninga at usna.edu
Fri Oct 6 20:29:02 PDT 2006

> has anyone had any success with APRS at 9k6 on AO51? 
> PCSAT2 is now removed from the ISS I'm looking to 
> experiment with  something else.

My understanding was that ECHO is operating with only 0.3W on the UHF digital downlink and that is 5 dB less power than even PCSAT2.  But this is only because the present firmware on the satelite does not account for bursty packet operations.  

SO the transmitter is on 24/7 all around the world transmitting even when no one is in the footprint so it is an inefficient way to conserve power for digital which only has uses over about 10% of the Earth.  From what I understand, it is on their TO-DO list to change the firmware so that the TX only is on when it has user demand.  THis soiuld allow for drqastically imcreasing TX power.

So we just have to wait until this is done, or hav a pretty good receive station.  But  all we need are a few receive stations to feed into the global APRS system and that is a big part of it.

Bob, Wb4APR

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