1940s commercial receiver (T1618E)

This receiver was found in a Radio Electronics from 1949. It is a superheterodyne of the time using 6 tubes.

300 Hz to 25 kHz TTL Oscillator (CB15626E)
The circuit presented consists precisely of an oscillator (multivibrator) that takes advantage of the 4...
General Purpose Alarm (CB12621E)
The critical components of this project from a 1978 publication are the transformers, which can be...
RF switch using diodes (CB9225E)
This circuit can switch signals in the 3.5 to 30 MHz band. We found it in a QST magazine from the...