Some people have really good luck with K7NV prop pitch rotators and others
like you have water related issues. I do not know what the seal looks like.
I do know that Kurt wanted the full weight of the mast and antenna on the
rotator to seal the gear box, I am sure that you heard this and tried it. It
is sad to hear that you have had so many rotator issues with the expensive
rebuilds. That is not what you except out of a prop pitch. Two of my prop
pitch motors are driving K0XG rings and those motors have the gearbox facing
downward so they have different water proofing methods (I hope).
John KK9A
Paul Christensen w9ac wrote:
I own a RT4500HD but waiting on cooler weather for installation. It seems
robust enough as it's replacing a small form-factor prop-pitch. Between
excessive water leakage after rebuilds and K7NV now SK, I was looking for an
alternative. The reliability of prop-pitch rebuilds has been disappointing.
N4CC and I have been changing them out every 1-2 years at a cost of $2,500
per rebuild. Crazy. We have a prop-pitch "graveyard" at our remote site
with something like six prop-pitches needing repair.
What seems to happen is that water ingress is caused by excessive surface
heat in the Florida summers, followed by cool rain. This creates a suck-in
effect. Because a prop-pitch is mounted upside-down in a tower, the seal
needs better protection without having to resort to a special covering. In
this regard, the DXE rotator seems much better. In fairness, the prop-pitch
was designed for a different application. But yes, only time will tell.
The first DXE rotator installation will turn a full-size 4L M2 40m monoband
Yagi at 140 ft and a 9L M2 6m Yagi at 155 ft. Both antennas are mounted on
a 3-inch chromoly mast. This fits within the DXE design spec. In
preparation for the installation, we used a crane back in April to change
out a Rohn 3-inch thrust bearing with the equivalent type from DXE. The DXE
bearing seems much more robust.
Paul, W9AC
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