This vibrato circuit was found in Motorola's 1966 documentation. The circuit uses transistors of the time that can be replaced with current common types. Power is done with 3 9V batteries.
This simple logic level tester was found in Radio Electronics from the 90s. The inverters are of...
The low-noise amplifier shown uses a rare Raytheon operational amplifier today. The circuit can be...
This circuit, found in American documentation, works as a voltage doubler, enabling the supply of a...