Using 4 tubes, this 1924 receiver combines new technologies as an intermediate frequency stage that was already beginning to appear. Listening is via phone and battery power.
We found this circuit in a Radio Electronics magazine from November 1976. The clock frequency is...
This circuit was obtained in a manual for radio amateurs from 1975. It is a circuit that allows the...
The LEDs act as diodes, so if good they will show the same characteristic curve. Arrangment shown...