This 4-channel mixer amplifier was found in an American publication from 1947. The circuit uses counterphase output tubes and a transformer power source.
This circuit is a small FM transmitter, capable of carrying its signals over short distances...
The purpose of this circuit is to obtain a voltage of 15 V with 1.5 A from a 48 V input. The...
This simple circuit must be powered by a voltage of 5 V. The integrated circuit is the 7400, but...