This circuit was found in a publication by Edelman from 1924. The power comes from the battery and the listening is through a high-impedance headphone.
The circuit presented consists precisely of an oscillator (multivibrator) that takes advantage of the 4...
The critical components of this project from a 1978 publication are the transformers, which can be...
This circuit can switch signals in the 3.5 to 30 MHz band. We found it in a QST magazine from the...