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.
USB58xx and USB59xx Devices Integrate a 2:1 Multiplexer to Support Reversible Connection of USB...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...
This configuration can be applied to other transconductance operationals. The circuit has a gain...