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.
In the figure we have an increased dynamic response configuration with the use of a transistor (TR3) in...
This tuned circuit was found in a 1966 Electronic Circuit Handbook. The transistor can be any...
This transmitter for the 40 meter or 7 MHz band was found in a magazine 73 for radio amateurs of...