This circuit transmits the audio signals from a telephone line to an FM receiver placed nearby. The coil has 4 turns of wire 28 in the form of 1 cm without core. The trimmer is 2-20pF or greater.
This circuit is from an Electronics World of 1964. The circuit can be made with modern...
This circuit is from an old American documentation from the 70s. Transistor 2N3904 can be replaced by...
We found this circuit in the March 1980 Radio Electronics magazine. The circuit used is the HA2400...