DDS synthesizers replace crystals CB Radios Posted on March 21, 2018 by AX05 — No Comments ↓ DDS synthesizers Michael Kane?shared his?post. 5 hrs Hope I am not getting outside of group topics, but for a few years now I have been experimenting with DDS synthesizers to replace crystals in old radio gear. This also makes it easy to use the numerous unloved and unwanted Aircraft and Marine radios that live in dark corners. I have a modded Cybernet CB using DDS for 28mhz. One of my DDS units is disiplined by GPS system. Michael Kane 4 March AWA HC-11 from 1960s with DDS synthesizers VFO. Frequency displayed is 7125 khz, common AM operation frequency in Australia. The HC-11 puts out around 45 watts carrier. The DDS unit also provides LO offset on receive. Radio is dual conversion, 1st IF is 1600khz then 455 khz. 13.8v operation. Allan Esterhuizen?how well did the old Cybernet cb work with the DDS unit ( I assume you were indicating a mk1 Cybernet which is a crystal synth radio ) I have been toying with trying a DDS in a couple of old mk1 Cybernet radios myself , one is a very nice performing Midland 13-892 , another is a sidewinder with pretty much identical innards Michael Kane?I have experimented with early Xtal synth and later PLL mixer Xtals. They all work well, although in all honesty I have to sometimes question my sanity when I have modern Amateur gear that does more. All these mods have been for 28mhz. I find it all fun though, and old CB are cheap to find and work well. Allan Esterhuizen?Michael Kane I see your point about the modern gear lol , I like the challenge of it more than having a need as I like experimenting. a friend of mine just doesn’t get it and argues the point all the time?:D Michael Kane?Sounds like my world, they shake heads but respect my ideas. Allan Esterhuizen?Michael Kane?My old midland is also a fairly sensitive radio and it even still looks good with its original mic as well , it is one of the reasons I was toying with the idea of using a dds in it Martin Fraser?I made this to replace crystals Dick Smith?Bought as a kit ? Martin Fraser?two modules from ebay and a bit of programming Michael Kane?For simple DDS, PIC controlled look up VK5TM Terry. You need to calculate values & program PIC. It uses the cheap AD9850 DDS Michael Kane?I have one of the Adafruit also. This is the one that is GPS disiplined and controlled by Arduino micro. Output a bit dirty, but filters fix this. Allan Esterhuizen?I have a stray dds unit that was designed for the SSB 6.1 kit radio available from China on eBay , they are very configurable and use a 16 x2 LCD display Michael Kane?Arduino controller with AD9850 and 4X20 LCD. Based on KANGA UK design.