HAM and T2X series of rotators have been improved adding a digital pulse counter to the rotators and digital controllers. Older rotators used a specially designed expensive potentiometer to determine antenna heading. Over time the pot wiper contacts get intermittent and noisy. This new design uses a special high temperature rare earth magnet and a reliable reed switch to count the rotations of one of the gears in the drive assembly. DCU-2 and DCU-3 have circuitry built-in to count the pulses and accurately determine the heading of the rotator to +/- 1 degree with repeatable accuracy. With the new pulse mode the noise and intermittent pot problems are no longer an issue. Older rotators can be retrofitted with the new gear and pulse board. Older DCU2 and DCU3 controllers will need a modification to the wiring and a firmware update that can be done in the field. The pulse mode is not compatible with the DCU-1 or the older controllers that have analog meters in them. Call Hy-Gain for more details! 662-323-9538.