This very simple amplifier was found in the Philips Databook of 1990. The circuit is suitable for headphones and other battery powered applications.
This transmitter, indicated for espionage applications, is permanently powered by the power grid....
Varactor diodes are our varicaps of today. This circuit for switching signals in an RF circuit was found...
Unlike the previous circuit, which is an inverter type, this one is non-inverting. The circuit...