> 1.) Why is this happening to the Ham M and not the Ham IV? Is there
> a physical difference in these two rotors that explains it? (I am
> currently unable to climb to inspect this -- a temporary situation,
> hopefully)
Probably something as simple as difference in paint ... ice will
adhere to some paints and not to others.
> 2.) How can I stop this from happening? Is it advisable to put
> spacers between the Ham M rotor base and the rotor shelf to provide
> more clearance for the rotating portion of the rotor?
Yes, I believe Hy-Gain even supplied suitable washers at some times
in their history. Any of the "clearance kits" that provide a way
for the cable (and connector for the newer rotors) to exit above
the rotor shelf will work.
> 3.) I don't recall ever hearing anyone mention a similar issue.
I had it periodically with all of the Hy-Gain rotors (HAM-M,
HAM-II, HAM-III, HAM-IV, T2X) when I was in Ohio. It was only
a matter of enough water around the base of the rotor when the
temperature fell below freezing. A 1/4" thick washer between
the rotor and shelf on each bolt should eliminate the problems.
73,
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Paul
> Kelley N1BUG
> Sent: Monday, February 16, 2009 9:03 AM
> To: towertalk reflector
> Subject: [TowerTalk] Ham M rotor freezing to accessory shelf
>
>
> OK, I know this has got to be a dumb question, but here goes.
>
> Most of my ham career I never used real antenna rotators. I used
> homebrew contraptions or the like. Now I have an 80 foot tower with
> a rebuilt and "upgraded" Ham M rotor (yes I'm aware of the
> controversy regarding the "upgrade" in question) and a 100 foot
> tower with a Ham IV.
>
> The Ham IV works fine in all seasons and weather conditions, never a
> problem. The Ham M, however, is useless much of the winter. Snow
> melts off antennas above, water drips down and forms a thin layer of
> ice on the rotor shelf. The ice is just thick enough to seize the
> lower rotating part of the bell housing so the rotor can't turn. I
> have climbed up there several times (in past winters) to verify that
> is the problem. If I chip away or melt the ice all is well until the
> next thaw/freeze or rain/freeze event.
>
> I have a few questions about this.
>
> 1.) Why is this happening to the Ham M and not the Ham IV? Is there
> a physical difference in these two rotors that explains it? (I am
> currently unable to climb to inspect this -- a temporary situation,
> hopefully)
>
> 2.) How can I stop this from happening? Is it advisable to put
> spacers between the Ham M rotor base and the rotor shelf to provide
> more clearance for the rotating portion of the rotor? If so, any
> recommendations or potential pitfalls to avoid? Are there other
> possible solutions for this problem?
>
> 3.) I don't recall ever hearing anyone mention a similar issue.
> Maybe I just wasn't paying attention, but, could there be something
> wrong with my "upgraded" Ham M that is causing this? I can't see how
> it could be assembled wrong and still work fine, aside from the
> icing, but...?
>
> Thanks in advance for any education and/or suggestions in this
> matter! In the previous couple of winters it was up there, this was
> a minor annoyance. If it was frozen and I wanted to turn it, I just
> climbed up and removed the ice. Now that I can't do that, it's
> driving me crazy! (er... more crazy? ;-)
>
> 73,
> Paul N1BUG
>
> _______________________________________________
>
>
>
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