This circuit is from a 90s Popular Electronics. It consists of a power source for bass amplifiers of common types at the time that used symmetrical power and separating filters.
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...