Top positive review
54 people found this helpful
Rough start, but OK now.
on July 6, 2009
I just purchased the Channel Master 9521A last week. Based on people's experiences documented here and elsewhere, I had reservations, but was assured by others of the unit's overall good success in the field. I decided to bench test the unit prior to installation. Good thing I did! Read on... all is well that ends well.
Not understanding how the 'sync' function actually worked, the first thing I decided to try was performing a sync operation, first thing right out of the box after wiring everything up. The unit just sat there with the motor humming and nothing moving. Turns out that this behavior was consistent with the unit's design, since the rotator was already in the state expected when a sync operation ends, thus no more movement was possible. The controller is a simple timer based design and simply sends current to the motor based on a time interval (< 1 min.). The time the controller attempts to activate the motor is sufficient to cause a full rotation back to 0 degrees, assuming everything is operating as expected.
The next test was to try the up/down arrow buttons on the controller remote to make the unit rotate manually. Unfortunately, it only rotated about 1/2 way around before reaching a point where it wouldn't turn any further, either forward or backward. It was stuck! I could here the motor being energized (hummmmm), but no movement was happening.
I am the tinkering type, so I decided to take the unit apart and see what the problem was and determine if I could fix it. For me, this was a preferable option vs. going down the path of return/repurchase. The disassembly started with removing the bottom cover and then removing the 5 Allen screws holding the motor/gear assembly to the housing. The rubber boot that surrounds the base of the upper mast had to be removed in order to allow the inner works to be removed from the housing. Everything on the inside of the box slips right out as one complete unit. Once I had it apart, I hooked the wires back up and conducted the bench tests all over again. Everything worked like a champ! Ran all kinds of tests, sync, manually movements, up/down adjustments, etc., everything just worked, which led me to conclude that something with the housing was 'binding' up the works.
In my final analysis, there is a total lack of lubrication where the rubber boot providing the weatherproofing makes contact with the housing. I applied a very thin layer of high quality grease to all the surfaces where the rubber boot that makes contact with the housing. I also put a light coating of grease on the main shaft where it just might contact the housing - though this contact is unlikely. I put it all back together and started to run the tests again.
Viola! Everything works as designed. Now that I understand what I've got and how it works, I have complete confidence that I can install the unit as planned.
I realize my approach isn't for everybody, but I hope my experience will help others in their decision making process.