This circuit was found in a 90s Radio Electronics. It produces an ultrasonic signal in a special transducer at the frequency of 2.25 MHz. No information was given about the transformers.
This circuit was found in a 90s Popular Electronics. The circuit uses several relays in order to...
We found this video amplifier with integrated circuits of the time in the magazine Electronics Now of July...
Found in RCA documentation from the 1970s, this circuit uses currently unusual integrated...