Found in a 70s RCA manual, this circuit uses a transistor of the time for an UHF L band oscillator. Details of the resonant circuit, which is critical, were not given.
This circuit can be used in demonstrations or science fairs. The circuit uses headphones and can...
We found this wiretapping circuit in a publication from the 90s. The circuit allows the cable...
This circuit uses a resonant reed switch at the trigger frequency. The circuit is from General...