Found in a 73 magazine for radio amateurs of the 1980s, this circuit uses a dual-gate MOSFET. This component is not currently common.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...