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.
This circuit controls the temperature of heating elements, which may be lamps covered with...
Obtained in documentation from General Electric this circuit consists of a biestable with...
This low-pass filter with 741 op and symmetrical source was found in the August 1993 issue of...