This is an amplifier circuit intended for modulating transmitters. The 5-tube circuit is from an American manual from 1947. The power supply uses 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....