We found this circuit that converts a direct voltage into a proportional frequency signal. The circuit is from an Electronics Now from April 1993. The JFET can be of any type.
This circuit uses separate sources for the power supply and the operational stage. The output...
This is a MOSFET version of a grid dip meter for frequencies between 1.8 MHz and 150 MHz,...
Found in the March 1974 Radio Electronics magazine, this circuit is designed to measure the level...