Found in Radio Electronics from the 90s, this circuit is intended for analog TV applications of the time. The transistor used as well as the module are uncommon components today.
This simple electroscope with bipolar transistors is not the most sensitive, but can detect static...
This oscillator for various frequencies was obtained from a 1980s telecom documentation. The...
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...