I'm trying to produce a small PSK31 beacon on a PIC chip using one port
(and an XOR gate) to initiate phase change, and others to control the mark space
ratio for driving a class D amplifier for the amplitude change.
With the currently available soundcard decoders, what frequency errors
are permissable in the PSK31 waveform which will still decode successfully?
Normally 32ms but what tolerance is OK?
Do the decoders lock, and then suddenly lose all decoding ability if the
frequency is too far off, or do they just slowly increase their bit error rate
with frequency error?