Found in Philips' 1967 documentation, this circuit makes use of period components. The SCR can be of any type, depending on the power of the controlled load.
For the 400 to 500 MHz bands, this circuitry found in an 80's documentation uses a very critical...
This is an interesting sound effects circuit that uses only discrete components. Components are common...
This circuit was obtained from an 80's EDN. The components used are still common. The circuit can be...