This circuit found in an American documentation from 1964, alters the duration of a pulse and can operate at frequencies up to 10 MHz. The transistors are from that time.
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...