This modulator amplifier for transmitters was found in a 1947 American book. The circuit uses an output with 4 tubes connected in parallel and in push-pull.
With this circuit, from an old operational datasheet, it is possible to measure the CMRR,...
Found in a Popular Electronics from the 90s, this circuit can be adapted to use LEDs. The power...
The circuits shown in the figure, that of an infrared video signal transmitter and receiver, were...