This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like...
The circuit presented is from a 1972 RCA technical documentation. The integrated circuit consists of a...
We found this transmitter circuit for different frequency ranges in a 1992 documentation. The...