Note that while this local oscillator redesign produces a better sinusoidal output it didn’t produce better audio output from the S-Pixie. This is because the mixer loads the local oscillator circuit, producing a signal very similar to the original design. I found that coupling the local oscillator and mixer with a 100 pF capacitor instead …
S-Pixie: Local Oscillator Analysis
If you’d like to join the discussion of the S-Pixie local oscillator check out Ham Radio Homebrew Projects on reddit. The S-Pixie uses a Colpitts crystal oscillator. I found a great video by Craig (devttys0 on YouTube) that explains how it works and discusses design considerations. Local Oscillator Analysis I’ve been having fun following along with Craig’s …