Many thanks for your replies Well, I'm hoping to use the MAX2828 IC, which was designed for use with OFDM signals, with FSK signals instead. I know it should work ok for modulation as it was already used here (**broken link removed**) on the Niwaka satellite for this purpose.
With regard to demodulation it has I/Q output ports in the receive chain so I'd be hoping to sum the I/Q output signals (after they've been converted from differential to single-ended outputs) then band-pass filter them and use an FSK demodulator IC, such as the Phillips SA 605 to demodulate the FSK.
In terms of amplitudes, they'd most likely be 200-700 mVrms. What do you mean by accuracy?