Today this frequency corresponds to the end of the FM band. However, in December 1958, when the circuit was published in Radio Electronics magazine it was the frequency used by American satellites.
The circuit is from the MC1539 manual, an operational one close to the 741. The transistor admits...
This circuit was found in an American documentation from the 90's. The circuit is intended for...
This telephone recording circuit was found in the June 1979 issue of Radio Electronics magazine. The...