This circuit is from a Radio Electronics magazine from July 1979. It uses the well-known IC 7107, a liquid crystal exciter that became popular in circuits of this type at the time.
This small transmitter for telegraphy (CW) or remote control operates at the frequency determined by the...
The circuit, from Motorola's 1993 Linear Interface ICs, uses an unusual operating system today....
This interesting source, obtained in a 2001 catalog, can vary the output voltage between -16 and...