This circuit was found in a 1967 General Electric documentation. Tunnel diodes can oscillate at very high frequencies. These are not currently easy to obtain components.
Varicap or varactor is the basic component used in this circuit of an American 80's documentation. The...
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
Using a 555 this circuit was found in old documentation, but it is still valid. | Clique na imagem...