This variable frequency (VFO) oscillator was found in a Japanese publication of 1962. Coil details (in Japanese, but can be deduced) are next to the diagram covering the 3.5 MHz band.
The circuit in figure 1 is a dynamic test for FETs. The characteristic of a FET is displayed in...
This beat frequency oscillator was found in a 1980s documentation. The original FET has a grounded...
This circuit produces signals that depend on the input control voltage. It is a Voltage Controlled...