This converter was found in the June 1991 issue of Radio Electronics magazine. The circuit uses common circuits at the time and its operating range can be changed.
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...