This FM micro transmitter was found in an 80s spy book. The circuit can work with equivalent FETs and is powered by a voltage of 0.6 to 6 V. Details of the coil are given next to the diagram.
The interesting circuit shown in the figure, can have its gain digitally controlled and present two...
This circuit includes the amplifier for the signals, being fully transistorized and using varicap...
The figure shows how to use a 12 V signal to trigger a TTL gate using an optical coupler. The...