Ok moved a bit further on this over w/e as my own HB-1A SMT build stumbled. I had added a solder bridge under IC6 (DDS) and IC5 (EEPROM). 101 SMT soldering means they should not have happened but I rushed the build and was late and made a simple mistake....
Anyway this post is to state that it looks like I have managed to add SSB to the AD9851 DDS and the RX chain. I have two alternate IF frequencies right now either 4.1952MHz or 11.0592MHz and could go either way. I also decided to drop the idea of making the SSB offset in the DDS and went with the 'standard' BFO setup where you use two crystal oscillators, set off set either side of the IF. Adds to the component count but then that isn't a bad thing.
The Softrock V9.0 Switchable BPF, along with the PIC-A-STAR and the QRP2004 designs have made me rethink the front ends and I am thinking that these should be switched. Now I don't mind winding toroids but I am thinking that some small SMT or through hole can type inductors might be workable for a 'no torroid' design.
Monday, 9 November 2009
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