If he lowers the rotor plate and mounts an accessory plate with a thrust
bearing he can swap out the rotor easily in case of rotor trouble.
All you have to do is secure the antennas so they don't turn in the
wind. I used a couple of slings over the boom, on opposite sides of the
mast, then tied them off to a couple of guy anchors on the ground to
keep the antennas from freewheeling.
Then I could unhook the rotor, fix it at my leisure, climb back up the
tower and replace it without taking down the mast or antennas.
The extra plate and bearing were cheaper than buying a spare rotor.
Of course I wound up with a spare rotor soon enough anyways but it did
make switching rotors easy (and I never had to switch it out after I
bought the spare one!).
I had two thrust bearings and made sure they were aligned vertically, I
would guess that a non-vertical mast would put a lot of sideload on a
rotor otherwise...
Just an idea I used... I don't know if there is some reason not to do
this, but I'm sure someone will let us know if this is a bad idea....
73,
George / KF9YR
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Pete Smith
Sent: Wednesday, April 09, 2003 3:55 PM
To: Dino Darling; towertalk@contesting.com
Subject: Re: [TowerTalk] Recommended T-Bearing for a 25G
At 10:57 AM 4/9/03 -0700, Dino Darling wrote:
>My friend will need a bearing for the top of his 25G. The top section
>comes to a point so my thinking was to lower the rotor plate and
install
>an accessory plate with the bearing mounted to it. Or, is there a
bearing
>that goes over the top tube?
>
I think this is overkill, particularly if he is using a galvanized or
chrome-moly steel mast. Mine has been up since 1995 without a bearing,
and
shows no signs of any problems -- the fit through the pointy-top is
loose
enough so that at <1 RPM and with similar hardness materials it will
probably outlast me.
73, Pete N4ZR
The World HF Contest Station Database was updated 2 April 03.
Are you current? www.pvrc.org/wcsd/wcsdsearch.htm
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Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
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