CM-9521HD Weight Specification
We really do not have a weight specification for the CM-9521A rotator.
- They were designed for antennas weighing ~15lbs along with a 3ft long upper mast.
- Like many products, we're sure it was over-designed to handle more, but installing something other than ~15lb antenna and an upper mast longer than 3ft, may shorten the life of the motor.
- The upper mast clamps can accept from 1" to a 1 7/8" pipe
- If you are going to run the upper mast through an upper sleeve on a tower, the upper mast must be 1 1/4" in order to rotate true(Centered in the upper mast mount).
- See Fig 2 on page 5 of the CM-9521A Instruction sheet for an example image.
- If you use smaller or larger diameter than 1 1/4" it could seize as it rotates.
- If you are not going to run the upper mast through a sleeve, then the diameter is not as important.
- If you are going to run the upper mast through an upper sleeve on a tower, the upper mast must be 1 1/4" in order to rotate true(Centered in the upper mast mount).
- The lower mast clamps can accommodate from 1" up to ~1 7/8" to 2".
- Also, make certain that you do not have an upper mast over 3ft tall.
- Too tall of upper mast creates excessive leverage in windy situations and can wear on or damage the thrust bearing assembly and upper mount shim bushing.
- Your mast could be damaged by high winds if it is longer than 3ft or if the antenna wind load projected area, is larger than 3sq ft.
- All of Channel Masters outdoor antennas wind load projected area are less than 3 sq ft and can be used with the CM-9521HD rotator systems.
- As an example, the antenna with the highest wind load projected area is our CM-4228HD with a wind load projected area of 2.14 sq ft.
- Our largest ~100 mile log periodic/yagi antennas wind load projected area are less than 2 sq ft.