For FB group Building Transistor Radios When I started building regen receivers, the first thing I found I needed was a simple signal generator. I have a function generator, but every time I want a different frequency, I had to readjust the controls. So I built a few RF oscillators to put close to the
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From FB group Vintage Transistor Radios For the last few months, ever since I started experimenting with oscillators on the AM broadcast band, my attitude towards auxiliary audio inputs has changed. Earlier I thought that it would be convenient to have an aux input. But I was leery of making changes to the collectibles radio
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I pulled a pill bottle out of my junk box, it had a single layer of solid enameled wire wound on it, and it measured 85 microhenrys. So I added the transistor, resistors and the capacitors to get it to oscillate at the low end of the AM BCB, around 540 kHz. The schem is
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I’m building a tuned circuit tester, which is a Franklin Oscillator without the parallel tuned circuit. I based it on the schematic I found at this URL. The first amp is a JFET in common drain or source follower configuration, which then drives the 2nd stage, a PNP transistor in common base configuration, so there
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When I googled I found a ‘stereo input’ FM transmitter. Most of the FM ‘bugs’ on the web and YouTube have a microphone. The circuit I linked to has left and right inputs, but mixes them to make a monophonic (not stereo) signal. After looking at the schematic I noticed a mistake, so I thought
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