Picked up at a garage sale a GE solid state clock radio, circa 1969 or so. All transistor, hot chassis, uses a high voltage transistor for the audio output stage. It worked, but weak stations couldn't be heard, moderate strength stations were distorted. Figured the detector diode, here the BE junction of a transistor, was too much.
I had some small shotkey rectifier diodes I salvaged from some small switching power supplies that had a very low diode drop, around a quarter volt. The transistor as diode measured about 0.55V. But I thought that these diodes tend to have excessive capacitance inside them, and make lousy detectors, but I decided to try one by touching the ends to the circuit board lands where the old detector was, once I removed it. It worked, and pretty well too.
Better than the old detector. As it was a surface mount part I soldered it to the trace side of the circuit board.
09-07-2014, 04:33 PM
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