Found in old documentation, this circuit consists of a simple power source where the transistor must be equipped with a heat sink. A indicated transistor can be the TIP32.
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”...