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.
New Low-Power PIC24 “GA7” Microcontroller Family Now Available CHANDLER, Ariz., Dec. 12, 2016 — The...
The purpose of this receiver is to monitor the signal from a nearby transmitter. It was published in an...
The LM567 is a PLL tone decoder that can also be used as a double oscillator as shown in the...