This 4-tube circuit was found on a Radio Craft from December 1945. The circuit has excellent sensitivity. Power comes from a power supply with a transformer.
This circuit is used to test an inductor (coil) allowing the observation of its opration in an R-L...
We found this circuit in a Radio Electronics magazine from June 1992. The circuit has a power...
This different audio amplifier was found in a 90's Electronic Design. The circuit uses components...