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.
It is the traditional version of a Galena radio with a germanium diode and a high impedance phone....
This trigger circuit is from 80s documentation. Transistors support equivalents and capacitors depend on...
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...