This TTL circuit has a well-known configuration, having been found in a Radio Electronics magazine from December 1980. The power supply must be 5 V.
The circuit consists of a MAT (Very High Voltage) oscillator that, applied to a protected metal...
A narrow range of frequencies around 1 kHz is rejected by the high Q filter shown in the figure,...
This transmitter circuit for the 27 MHz band uses 4 common FETs and has the details of the coils...