For my homebrew 20m SSB rig... Following up on the success of the audio pre-amp, I built up the product detector from the BITX20, including the 4dB pad. Here's me testing that with the BFO from the BITX20 modified down to 9Mhz. The VFO here is an SI5351-based bench oscillator running my own software, that I made back in the fall. The audio amp is my own design. #HamRadio #AmateurRadio
https://youtu.be/Xko_p5t7XzU?si=Kyun8OxhLAt1iVQw