This circuit is from a Radio Craft from the 1940's. The circuit employs 5 tubes and must be battery powered. See that the circuit is quite critical, especially in relation to the sensor coil.
This receiver for the mid-wave band was found in a documentation from the 60's. The transistors are made...
This circuit is used for cable checking. We found it in the Radio Electronics magazine of December...
Suggested by a Philips documentation from 1970, this circuit uses period components, operating at 50...