We found this oscillator in an old documentation. The crystal frequency can be different to get other output frequencies.
This circuit uses an MW radio tuned to around 540 kHz to detect atmospheric signals, for example, from...
This project was found in a 1982 publication. It is a small transmitter that can send signals from...
This circuit is from a 1960 book by Hugo Gernsback. The transistors are germanium from the time....