This circuit can generate signals of crystal multiple frequencies. The resonant circuit must be according to the desired frequency. The transistor must match the frequency.
This circuit deactivates devices powered by the power grid so that when the power returns, they do...
The trigger signal for this circuit is an audio tone. Tones up to close to 100kHz can be used. The...
Found in the March 1974 Radio Electronics magazine, this circuit is designed to measure the level...