This transformerless circuit was obtained in a 1965 publication by Ferranti. The components are from that time, with emphasis on the type of engine used.
The circuit shown is a documentation on 80's tunnel diodes. The frequency depends on the delay line...
This circuit generates excellent sinusoidal signals and has the frequency adjusted by VR1 which is...
This circuit was adapted from an Italian publication that no longer exists. This is “Onda Quadra”...