2017-05-04 Interrupting The Supply V to the Oscillator

I was working on the 27 MHz oscillator for testing the regens, and I thought it would be a good idea to turn the carrier off for a small fraction of a second every 1 or so seconds.  So I built a two transistor flasher with a third transistor to invert the pulses.  Instead of mostly off with an on pulse every second, the output is mostly on with a very short off interruption every second.

I built the circuit and I put a LED on the output and found that it was always off unless I touched the base of the first transistor.  I found that the two transistors had too much gain, so I added the 22k resistor as a collector load resistor for the first transistor.  The circuit started working properly.  The interruption rate is 1.4 per second.

I got the Suntech AM-FM-SW Radio for $20.  It’s so cheap and the performance is seriously lacking.  The FM band has images that seem as strong as the stations, so I put the extendable antenna down, and the performance wasn’t as bad.  But then I can’t hear the difference between the quiet spots on the dial and the unmodulated carrier of my oscillator.   So now I have my oscillator powered by the interruptor circuit, and the short interruptions make it easy to tell the difference between the carrier and other signals.

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