How I built a shortwave Armstrong FET regenerative receiver

  
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I had never worked with ` common base` or `grounded base` designs before and you know, I still don`t understand how they can amplify. Another thing, I had never used a bipolar transistor in a regenerative stage before, but had read that the amplification factor of a bipolar transistor in a regenerative receiver is actually much higher than for a FET
How I built a shortwave Armstrong FET regenerative receiver - schematic

(I have since learned that an element with too much amplification makes for very unstable regeneration control - like this one had). Another thing that intrigued me was Mr. Kitchen`s so-called " Floating Diode Detector. " I would have never believed that you could get away without a DC bypass of some kind, but there it was and I just had to try it. Finally, I had never seen a LM386 audio amplifier IC configured for high impedance like this and I wanted to see how well it would work. I began stuffing the circuit board with parts and soldering them in. For a coil form I used a pill bottle I got at a pharmacy. When complete, I mounted the circuit board and all the other parts very neatly in my little aluminum radio chassis and turned on the set. Well, I could hear radio signals, but the truth is, the radio sucked. I mean, it sucked really badly (sorry Mr. Kitchen), I can`t lie, it just sucked. I was hoping I could get this disaster to somehow work without such "squirrellyness" so I decided to add a RF stage to its front end. After looking over the circuit board, I figured that I could easily grind out a portion ofthe circuit board`s ground plane with a tiny diamond burr I have. That way, I could create the pads for an RF stage that I wanted. Well, I did, and it was easy to do and so I mounted a 2N2222 transistor for the RF amplifier and proceeded to put in all the parts for the other stages too. First thing I noticed was that...



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