This circuit is from an American manual from 1975. The transistors are types of the time, but equivalents can be used, as well as the relay that can be according to the supply voltage.
This transmitter, indicated for espionage applications, is permanently powered by the power grid....
The maximum frequency of the oscillator shown in figure 10 is on the order of 5 MHz, depending on the...
This circuit was found in the SGS manual of linear integrated circuits of 1982. The integrated circuit...