1975 Frequency Counter Project

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Hi Friends. While going through my papers, I found the plans for a frequency counter project that I built in 1975. I always tried to keep decent records of my major projects and this was a major project. I was 25 years old then, and had good eyesight to hand wire all these chips.

I do not recommend that you try to make this project! Why? Well, all this stuff can be replaced with one IC today. I find that amazing.

aA little about this frequency. The upper frequency limit was 18 MHz. I had a pre-scaler that allowed up to 180 MHz top frequency. This counter had a time base from 1Hz to 10 MHz in X10 ranges. I also had a stopwatch built in that used an external plug in box or logic to control the on and off counting. I never did use this function, but did find the time base handy.

The power supply was commercially available. The master oscillator was built in a separate box and had a calibration adjustment that extended out the back of the box.

73 - Dave N2DS

My 1975 Frequency Counter Project - Block Diagram

1975 Frequency Counter Project – Block Diagram – Larger


My 1975 Frequency Counter Project - Diode Matrix

1975 Frequency Counter Project – Diode Matrix – Larger


My 1975 Frequency Counter Project - Input Circuits

1975 Frequency Counter Project – Input Circuits – Larger


My 1975 Frequency Counter Project - Time Base Divider and Control

1975 Frequency Counter Project – Time Base Divider && Control – Larger


My 1975 Frequency Counter Project - Output Display

1975 Frequency Counter Project –Output Display – Larger