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 one of many that we have in our section. It was taken from the Electronics...
This is a bridge for the measurement of low value resistances and high values too. The circuit...
This circuit for the two-meter band of radio amateurs was found in 1980s documentation....