Spring 2009 Issue

CDE/Hy-Gain Rotors
How to Keep ’em Turning – Part II



In Part I of this series, we looked at how to repair the most commonly experienced problems with bell-shaped CDE/Hy-Gain rotors. Despite Murphy’s best efforts, not all rotor (rotator) system problems are found on top of the tower. Sometimes the problem can be found, and corrected, in the shack. In this part, we’ll cover what can happen to the various styles of controllers that are used with these rotors and how to identify and repair those problems.

By Brad Pioveson,* W9FX

Photo 1. Examples of three rotor controllers. The top one sports a single lever-operated switch and a large meter. The bottom two show the later additions of the direction control and brake switches (lower right in both controllers), as well as the calibration and on/off switches (upper right on both controllers). (Photos by the author)

An often-seen post on antenna-related e-mail reflectors inquires about what kind of controller one can use with specific types of CDE/Hy-Gain rotors. The answer is an equivocal, “It depends.”

The history of these rotors can be traced back to the days of the CDE Ham M-series. These first rotors were delivered with a controller that sported a single, lever-operated switch and a large meter, housed in a compact brown or black plastic case (photo 1). That single-lever switch performed all the functions needed to move the antenna remotely. When the operator pushed the lever to the left, the switch energized the rotor’s brake-release solenoid while applying power to the rotor motor, turning the rotor in the counterclockwise direction and simultaneously engaging the DC circuit that turned on the indicator meter. When the operator released the lever switch, power was simultaneously removed from the DC circuit, the brake solenoid, and the rotor motor. The brake wedge, no longer held back by the energized solenoid, thus instantaneously slammed into the nearest groove in the rotor’s lower housing, regardless of any movement of the antenna/mast assembly. Inertia was a diabolical enemy of these brake wedges. Hams with sizable antenna arrays mounted above Ham M rotors soon learned how to change brake wedges, as they would often shatter from the rotational torque applied to them.

There were four “series” of Ham M rotors. Series 1 or 2 rotors must be mated with Series 1 or 2 controllers. If you are unclear on that point, let me suggest you read that sentence again. Failure to heed this warning invariably results in expensive “smoke” being liberated from both rotor and controller.
Series 3 Ham M rotors featured improvements that changed the rotors into the electrical configuration still in use today. In other words, a Series 3 Ham M rotor is electrically the same as Ham II, Ham III, Ham IV, Ham V, and TailTwister rotors. The Ham M Series 3 and 4 controllers will electrically operate any of these rotors. It’s not a terribly good idea to use the old single-lever controllers on these more modern rotors for the reasons outlined above. If, however, you are in a pinch, have a light load on the rotor, and are careful to avoid moving the antenna during high winds (which might add to the rotational torque on the system), you can get by with an old, single-lever controller.

The single-lever controllers will happily work without any kind of restrictions when coupled to the TR-44, CD-45, and, CD-45 II rotors. These rotors are not equipped with brake wedges, so the lack of the ability to independently control the brake is immaterial.

The Ham M Series 5 rotor from CDE addressed the problems with brake-wedge shearing, a problem that plagued the single-lever controller owners. With this new model, CDE introduced the three-switch controller. This unit sported one push-type lever switch each for CCW and CW rotation, and a third switch to engage/disengage the brake wedge. With this innovation, CDE changed the name of their rotor to the Ham II.

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