I've done something similar to what Larry has done; however, I use heavy
duty, flexible vinyl and fold it into a simple cone. I wrap the top of
the cone around the mast above the thrust bearing so it forms an
umbrella to protect moisture from settling on or into the bearing. The
vinyl can obtained as scrap from fabric shops or upholstery shops.
Another trick, although the mechanical purists might not approve, is to
pump grease into the thrust bearing until it comes out of the housing.
Make sure it is distributed all around the contact surface between mast
and bearing. The grease is incompatible with water and keeps ice from
getting in between the mast/bearing surfaces. Messy, but works.
73, Joe
W1GOR wrote:
Martin,
I've had similar problems with the mast freezing in the sleeve... My
solution was to make a cone-shaped guard and fasten it around the mast
slightly above the sleeve opening (seal it well). It can be of
sheet-metal although I used fairly stiff plastic sheet and heated it
to form the cone. When done properly, any moisture (rain, snow, sleet)
will be diverted away from the mast-sleeve junction and the mast will
not freeze in the sleeve. You might want to apply some low temperature
silicone grease to the mast, where it passes through the sleeve.
Don't use ordinary grease because it is not capable of withstanding
very low temperatures without getting stiff. If you have enough space
between the mast and sleeve, a sheet of TEFLON can be used in place of
the silicone grease. According to DuPont, TEFLON is the slipperiest
material on Earth...<grin> By the way, if you can find a GIANT
FUNNEL, you will have most of the shield right from the start...!
73, Larry - W1GOR
There are 10
types of people
in the world;
Those that
understand
B I N A R Y
and those
that don't.
----- Original Message ----- From: "Martin AA6E" <msembx-aa6e@yahoo.com>
To: <towertalk@contesting.com>
Sent: Wednesday, January 19, 2005 11:54 AM
Subject: [TowerTalk] Frozen Rotor
Winter greetings!
With the help of a good antenna guy, I installed a roof-mount tower (20
ft Rohn 25) with a Yaesu G-1000 holding up a 3-el SteppIR on an 8 ft
mast. Nothing exotic here, but it gets out nicely.
We've had a couple of nights this winter of below 10F. I've found the
rotor just won't budge until morning, when things warm up into the
teens. What's going on?
There could be some ice in the tower sleeve. Is that the most likely?
Shouldn't the G-1000 be able to break through? The rotor does not slip
against the mast. (Indicator does not move.)
What do people do to prevent this? Lubricate the sleeve, provide a
weather shield, heating tape, ...?
73, Martin AA6E
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless Weather Stations", and lot's more. Call Toll Free,
1-800-333-9041 with any questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|