This circuit is from an old Japanese publication of 1962. The circuit uses two batteries, one for the filaments of the tubes and the other one of high voltage for the plate circuits.
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...