This detector was found in an old Electronic Design using transistors of the time. The circuit can be made with modern equivalent transistors. See the charts with your performance.
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...