This circuit with the PLL4046 was found in the October 1994 Electronics Now magazine. The transistor is low power, and the volume obtained is small.
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...