Oscillator HA7210 (CB22402E)

This circuit is from an old documentation and can be used to generate signals in different frequency bands.

Atmospheric noise monitor (CB21066E)
This circuit uses an MW radio tuned to around 540 kHz to detect atmospheric signals, for example, from...
FM transmitter (CB16327E)
This project was found in a 1982 publication. It is a small transmitter that can send signals from...
Medium wave range booster (CB21677E)
This circuit is from a 1960 book by Hugo Gernsback. The transistors are germanium from the time....