Based on a PLL 567, this circuit serves as a receiver for the CB9574E circuit. S tuning is done in R1 and it is used for frequency modulated signals.
This circuit, which in our times would be called a shield, can also be used with other loads. The...
This circuit is from an old American documentation from the 70s. Transistor 2N3904 can be replaced by...
This application of the 555 was found in the November 1992 Radio Electronics magazine. The...