Tim; I believe there are two pots each for the azimuth and elevation meter adjustments. One pair are for the internal meters, the other pair for 0-5V to be used by the TrakBox (or similar) ADC. Make sure you turned the correct pair. However first I would make sure the internal 7806 voltage regulator is producing 6 volts and does not oscillate or have noise on it. Dig out a DVM and scope to make sure. Those regulators, if not properly bypassed with a capacitor may oscillate.