The gain of this step is controlled by the feedback circuit depending on the strength of the input signal. The circuit will operate with modern general-purpose transistor.
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...
This commercial medium and short-wave radio was manufactured in Japan in the 60s. The circuit has...
General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs...