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.
This circuit is from a 1974 publication, but it can still be easily assembled today with BC548...
This driver for audio signals using the TAA435 integrated circuit was found in Philips 1968...
We found this circuit for old tape recorders in the December 1972 Radio Electronics magazine. The...