I made a few changes tonight and feel pretty positive about the limited time that I had to work on it.
I removed the tank circuit and replaced it with a resistor on the collector of Q1.
(The oscillator should now be a wide band design for future projects.)
I re-biased Q2. (This morning before work I built a spreadsheet that helped me better
understand the values of the components and the impact on the transistor.)
The loudest harmonics are now about 42dBm down. (The two loudest are the 6th &
The power at the output of the filter is about -10 dBm or .1mW
I updated the schematic with the changes.
Move this to a copper board with islands or Manhattan pads
Design an additional gain stage (or two)
Research "class AB" and "class C" amp options