This circuit was found in a Radio Electronics from February 1966. The circuit operates with a common battery and the frequency is given by the resonant LC circuit.
Found in Popular Electronics from the 1980s, this circuit can use more modern transistors such as...
This circuit is from a Radio Electronics from February 1970. The integrated circuit is an...
This is stage is transformer coupled and was found in na old publication of the year 1958. The...