This circuit turns off after a time given by capacitor C1. This component can have from 1 to 1,000 uF depending on the desired time. The circuit is from an Electronics Now from June 1995.
This oscillator has its frequency controlled by crystal and its frequency can be between 100 kHz...
This small crystal microphone transmitter was indicated in an 80s spy book. The range depends on...
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. The...