I watched the YouTube video of Radiofun232 testing the PSO that he built according to the schematic he showed. I modified it somewhat. My objective was to decrease the frequency down to 400 Hz.
I used three 0.1 uF capacitors and a 0.56 uF instead of the 0.47 uF. Instead of 1k I used 2.2k. I replaced the 1.8k collector load resistor with a 2.2k. I also used 9 volts, but I changed the base bias resistors from 3.9k to 4.7k, and from 12k to a 10k and 25k trimpot in series to allow adjustment.
I used a 2N3904 instead of the BC547. I adjusted the collector voltage to 4.5 volts. I could connect the +9V, and sometimes I would see a slight blip on the scope and on the frequency meter, but not a continuous oscillation. There is not enough gain to sustain oscillation. The lack of an emitter resistor and bypass capacitor means this circuit will be too sensitive to temperature changes.
