I already have a variable resistor in place of the gain resistor (which controls sweep). Now I have my insturment cluster apart and 2 tachometers ghetto hooked up to the tachometer leads inside the insturment cluster. One tachometer I have is the original 6 cyl tach from the car the engine came from and the other is my 4 cyl tach that belongs to the car im calibrating it for.

Now I'm trying to calibrate the tachometer by adjusting the variable resistor and comparing the needle to the 6cyl tach readings while holding the accelerator at a certian RPM. But that is way hard because the higher up the RPMs I go the greater the error in the calibration shows.

Does anyone in the Atlanta area specialize in tachometer calibration?

Does anyone in the Atlanta area have a function generator (square wave capable)?


I'm willing to pay for help with this.