Found in a 1947 publication, this circuit uses 4 parallel/push-pull tuber in the output stage. The circuit employs dual power supply with two rectifier tubes.
This S-meter circuit was found in a 1976 publication. The circuit is used to measure the signal...
Several versions of this circuit can be found on this website. This makes use of FETs that can...
With the circuit shown in the figure we have a frequency modulation which is produced by a...