Found in American documentation from the 90s, this circuit can measure frequencies on a linear scale from 0 to 1 kHz. The components can be changed to measure other ranges.
This control circuit up to 1 kW was found in a 1967 RCA documentation. The components are from...
This circuit was found in 1967 General Electric documentation. The transistors of the time can be...
This circuit produces signals in the range of 200 Hz to 2 kHz. We found it in the magazine...