This 4-tube circuit was found in an American publication from 1947. It is intended for audio distribution lines using a transformer source.
March 2017 – Mouser Electronics already has the new Texas Instruments INA260 digital current and...
This tester from a 1960 magazine is only for capacitors with insulation voltages above 200 V (110...
This source was obtained from a former publication for valves but also serves for powering common...