> I'm not sure the 4800hz statement is correct. The data stream is 4800 > bits per second which is put through GMSK before hitting the radio > which requires a pretty flat response, which is why it is injected > into the modulator directly (not through the audio chain) and pulled > directly from the discriminator. I don't think the 4800bps directly > maps to 4800hz.
I would like to point you to the bit synchronisation sequence before the frame synchronisation pattern which consists of nothing but a 10101010101010... sequence which at 4800Bd and which will map to 4800 Hz, or very close. The actual data will be a bit less unless the 10101010.. sequence crops up. I can assure you that sampling the data at 48000 Hz and taking the bit value every ten samples works beautifully! Jonathan G4KLX
