This is a simple tubed mixer from the 50's. The circuit does not include the power supply and has 3 inputs with independent controls. The tubes are double and the inputs are high impedance.
This simple oscillator with just one transistor has a frequency determined by the characteristics of the...
This Zero Crossing Detector was found in a 1972 RCA manual, but it can be made using any modern...
The circuit shown was found in a Japanese publication from the 1960s. Transistors can be...