Found in a 1967 EEE, this circuit oscillates at 20 MHz according to the values of the given components. The FET can be of general use. The coil has only indicated the number of turns.
Found in the CQ radio amateur magazine, this circuit generates a standard 100 kHz signal. The...
When the sensor connected to points A and B is activated, removing the ground from the base of Q1...
This crossover signal for model railways was found in a Popular Electronics from the 90's. The...