[amsat-bb] APRS to Moon orbit?

[Ross Whenmouth]

Nick, LORA uses chirp spread spectrum, with a signal that is ~ 125 kHz 
wide (in 11 bps mode). If we have sufficient spectrum to accommodate 
this, then it might be worth considering.


Sorry Bob, I must have miss-read your original posting? as I did not 
realise that your proposal was for a backup command link as opposed to 
an APRS user port. Considering the wide coverage area, and the need for 
only a small number of backup-capable ground stations, would it be 
reasonable to increase the requirements of the backup ground station to 
that of a "big-gun" EME station?

If the RX chain of an FM receiver was non-linear before the last IF 
filter, I'd expect that radio to be terribly susceptible to 
intermodulation? (though after the RX RF has passed through the last IF 
filter, then yes, linearity does not matter for FM). When I get a 
chance, I'll have to do an experiment with an FM RX, an RF signal 
generator and an oscilloscope connected to the 455 kHz IF...


73 ZL2WRW
Ross Whenmouth