Initial Design
The most prominent area of my wish list is the DSP board. The orginal board is obsolete, large and messy to interconnect. This seems to contradict the realitively simple clean design of the RF sections.

My design would break the DSP board out into a separate enclosure. This would allow the DSP to be used with multiple RF front ends. Also with the increased horsepower, it might be possible to operate two radios instead of just one. In addition, the DSP could be used as an audio processor or modem in conjunction with a commercial transciever.

It would be a simple to setup a audio switching arrangement to switch the DSP between radios, mic, speakers or PC sound card. This will be another component for my modular station.

The 2 meter RF/IF would remain largely unchanged, although re-packaged. I might also look at using newer MMICs to see if there is any performance gain.

The component parts of my redesign would be:

• DSP board  More details
  This would hold the DSP, CODEC, host serial interface and supply circuitry.
  
  
• RF/IF board  More details
  The receiver RF amplifier and filter, the transmitter PA and common bandpass filter, mixers and cyrstal filter from the orginal design.
  
  
• LO/interface board  More details
  The two local oscillators, microcontroller, regulator and power switching and audio interfaces.

For a mobile intallation it might be nice to piggy back the DSP board in too. The layout will take into consideration stacking all three boards in one box.

One of my orginal thoughts was to go to an all surface mount design, however; this appears to be impractical since coils are not readily available in SMT. The idea was to provide a shielding ground plane on one side of the board. A more practical approach would be to interleave unetched pcb or brass between the boards.

Another layout goal is to use board mount connectors where ever possible. This eliminates messy wiring, but wouldn't proclude its usage if a different connector or packaging arangement were used.

It would be nice to use connectors for board interconnects, but in an RF design, coax is still probably a safer choice. There would be six connections between the RF/IF and the LO/Interface boards. RX power, TX power, ground, LO1, LO2 and IF2 output. The first three could be done in wire, the last three in RG174 coax.

The LO/Interface board would have 13.8VDC and ground power input, AF in and out, and serial in and out for control. I would also include an accessory control connector for external PA or T/R switching. These hopefully can all be done with board mount connectors.

The DSP board would have similar 13.8VDC and ground power input, AF in and out, and serial in and out for control of the LO/Interface board. Again I would like these to all be board mount connections.