At the moment we have two boards plus the backplane thought throught.
1. USB etc and backplane interface board with Cyclone II FPGA.
2. Sound card replacement board - Wolfson A/D (or TI etc) for Rx I/Q
signals and TVL320 microphone/line input. Dual D/A converters,
speakers/headset and I/Q to QSE. Looks like this board could also do CW
Tx ( I/Q signals and keyer plus sidetone ) if wanted.
Future boards
3. LTC 2208 with FPGA for Rx. NCO inside FPGA with D/A converter to
provide Tx local oscillator.
4. Ham band BPF board, use bus switches so can be switched into Rx or Tx
chain. HPF's, LPF's, switchable attenuators and preamp(s).
5. Rf board - QSD/QSE with AD9954 DDS and say 1W output ( only use QSD if
we solve NF problems). PIN diode or bus switches for fast Tx/Rx swithcing.