This circuit is from a March 1967 Radio Electronics. The circuit applies to general purpose SCRs such as the TIC106, C106 and others. The test is done by increasing the gate voltage to the trigger point.
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....