Module # 120 VFO / BFO - MAX-SSB Transceiver Project

Here I test the completed VFO / BFO Module # 120 for the MAX-SSB homebrew HF transceiver. The VFO/ BFO module is controlled by the Front Panel module # 110 and provides the VFO (variable frequency oscillator) to the Mixer module # 220 and the BFO (beat frequency oscillator) to the Product-Detector / Balanced-Modulator. The front panel controller set the operating frequencies and drive levels for all three clock outputs of the Si5351 as well as calibration offset for the main crystal in the Si5351.
Schematic:
www.remmepark.com/circuit6040/...
73 - Rick - N3FJZ

[@alevans51]

So what are going to do with such a precise VFO/BFO on your transceiver?

[@stevebabiak6997]

Perhaps communicate with a UFO ;)

[@Circuit6040]

I find myself asking that same question sometimes :-) I guess the simple answer is "because it could be done". For voice SSB, a few 10's of Hz ether way is hardly detectable, and I don't plan to do any digital work with the rig that would require that kind of precession, so I guess it goes back to my days working in an instrumentation standards lab in the '80's where precision was everything and took a lot of effort and equipment to achieve what a few dollars can do today. It's just fun and so satisfying to be able to do it now at home :-) . 73 - Rick - N3FJZ

[@Circuit6040]

No, that was earlier, They were the ones that sent me the plans to build this thing :-)