This 1970 Electronic Design circuit uses a varactor or varicap. The circuit divides the frequency of a 150 MHz signal by 2. Similar versions appear on this site.
This VCO or Voltage Controlled Oscillator uses common components. TR1 can be a BF245 and TR2 a...
The transformer for this project found in a 1986 documentation is an output type, found on old...
We found this circuit in a 1978 documentation. The SCR conducts when the regulator's output...