This circuit from a Radio Electronics from October 1965 shows how to obtain the action of an SCR when triggering a relay using two transistors. The relay is according to the circuit supply voltage.
With the name of transitube we find this MW receiver in documentation from the 50's. It uses a...
This type of circuit is interleaved between a microphone and a transmitter in order to improve the...
We found this circuit in an Electronics Now magazine from June 1995. The transformer has a primary...