This circuit with a differential pair was found in the August 1974 Radio Electronics magazine. The frequency is determined by L1 and the variable capacitor.
Found in the October 1992 Radio Electronics magazine, this oscillator is controlled by switch S1....
This circuit was obtained in a 1976 amateur radio manual. The circuit can be made with a 2N2222...
The component used in this circuit is not very common today as the circuit is from the 80's. It...