[amsat-bb] 9600 vs 1200bps sensitivity

["Chris Hill" <chris.hill@xxxxxxxxxxxxxxxx>]

Hi All,

Can anyone refer me to a definitive document showing the minimum signal
required to receive:
a.  1200bps AFSK AX.25 (Bell202 over FM i.e. "normal packet radio")
b.  9600bps CPFSK AX.25 (as used on the UoSATs, etc)

By my calculations, 9600bps CPFSK is capable of successfully decoding a
_weaker_ signal than 1200bps AFSK.  Receiving the UoSATs, I could copy
9600bps without the S-meter moving;  I needed at least S2 to copy 1200bps
AFSK.

However, I have heard that the Kenwood D-700A could decode a weaker signal
at 1200bps, than at 9600.

Observation, measurements, and/or a reference document or URL, are most
welcome!


73 Chris vk6kch




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