Filament source (T398E)

Despite being transistorized, this is a constant current source circuit for 1 V valve filaments such as the 1H4 tube.

2-transistor LC oscillator (CB22388E)
This circuit was found in English documentation from the 90's. Transistors are general purpose types....
Precision Rectifier (CB24972E)
This instrumentation circuit is from the June 1986 issue of Radio Electronics magazine. Equivalent...
Audio Remote Control (CB24138E)
This is an interesting idea that we found in the May 1971 issue of Radio Electronics magazine. It can...