Short Wave Converter (T987E)

The conversion range of this circuit depends on the coil. The circuit uses two tubes, and the power supply is not provided.

Sonalert Alarm (CB24129E)
The sensor is S1 in this alarm that we found in a Radio Electronics magazine from May 1971....
Repeater Beeper (CB20678E)
This circuit was found in documentation for radio amateurs of the 1980s. This is the so-called...
Astable with starting circuit (CB21099E)
We found this circuit in an American documentation from the 90's. The circuit makes use of general...