Found in a 1924 Gernsback publication this circuit uses 4 batteries for power and loop antenna. Listening is over a high-impedance type earphone or loudspeaker common at the time.
This circuit excites incandescent lamps by making them flash alternately. There are 4 outlets and...
This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This circuit is from American documentation from the 90s. The configuration is very current and can...