View Single Post
  #9   Report Post  
Old May 18th 05, 07:26 AM
Bernard
 
Posts: n/a
Default

The world seems to be going to direct-conversion I-Q receivers with the
baseband going to a DSP for processing. Reverse for TX. I think this
would work fine for any mode on 2m, including FM if you're clever with
your algorithms.


You are right, for example most of the 802.11 or Bluetooth solutions are
zero-IF, but I don't think that this is ideal for Ham Radio (the main issue
is re-injection of the LO into the RX). A better option (for us) is the low
IF option (like in the DSP10). The DSP10 has an IF at 19.665 MHz and one at
15 KHz. The concept is excellent but slightly overdesigned for what I want
to achieve. The drawback (when compared to zero-IF) is that the low-IF
receivers still requires dual conversion and IF filters to achieve any level
of performance.