We found this circuit in a 1956 Sylvania publication. It serves to monitor telegraph transmissions being placed next to the transmitter. The circuit is indicated for the range of 80 and 160 meters.
The base of this circuit is one of the four Norton amplifiers existing in an LM3900 integrated circuit....
This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light...
This circuit of an old American publication uses RF transistors to obtain unit voltage gain, but...