We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a...
We found this circuit in a 1976 publication for radio amateurs. It was originally intended for use in...
The integrated circuit used in this small transmitter is not very common today. The coil has its...