[VHFcontesting] Radio Shack TV Rotors

[Anthony Rick]

It may be that you need to re-lubricate the gears.  The heavy weight gear
lube denatures after about 5 years of collecting depri and moisture and
turns into a ridged paste. WD-40 may exacerbate the problem because it is
actually a better solvent than a lubricant.  It will wash away the heavy
gear lube and then evaporate, leaving less even lubricant.

My advice is to take it apart and spread some bearing grease around the
gears. I usually use marine grade bearing grease (the blue stuff) because it
is less affected by water and salt.

Here is some basic instruction for getting these things apart.  This is just
off the top of my head so it may not be exact:

1) Use a large plastic storage bin for your workspace.  You will need this
because once you pull the shaft out of the gearbox all off the bearings will
roll out.  The first time I did this I was on my hands and knees with a
flashlight trying to find where the bearings went.

2)  Take out the bottom screws and pull off the bottom cover

**In the following steps think of a way to mark the alignment of the shaft
and gear set.  Their is a limited sweet spot (a few teeth) in which the
shaft and gears will work properly.  Of you end up off the mark you will not
get 360 degrees of rotation

3) Remove the snap ring from the shaft

4) Pull the shaft out from the top of the rotator

5) Now you should be able to pull out the whole gear set and motor from the
bottom

6) Use a degreaser to clean everything ( I used brake cleaner) and then
re-lubricate.

7) in reassembly, you will need to balance the bearings on a small
circular impression that they can roll off of before the shaft is inserted.
I found that covering them with a large glob of bearing grease holds them in
place pretty well but it still may take a few tries.

Good luck!

Anthony
NR9R

_______________________________________________________________________________________________________
From: "John Geiger" <aa5jg at lcisp.com>
To: <VHFcontesting at contesting.com>, <vhf at w6yx.stanford.edu>, <
50mhz at mailman.qth.net>, <6meter at yahoogroups.com>
Date: Fri, 27 Jun 2008 16:19:21 -0000
Subject: [VHFcontesting] Radio Shack TV rotors
I have a Radio Shack TV rotor which has been in use for around 10 years, and
is currently turning my 2m and 70cm beams.  It handles the antennas with no
problem, but I am wondering if anyone has any ideas or experience as to the
life expectancy of these rotors?  I realize they are intended for TV antenna
usage-probably being rotated once per day or so.

It has had a problem with becoming stuck occassionally.  The first time it
happened was probably 4 years ago.  I took a large wrench and hit it a few
times, and that seemed to unstick it.  It worked for a couple of years until
it became stuck again.  When that happened I hit it again and that time
sprayed some WD40 underneater the rubber boot on it into the rotor track.
This worked again, and I have had to do that a couple of times recently, but
it would always go back to working after a little while when the oil
penetrated through the rust or whatever.

The sticking seems to happen more often now as it happened during the June
VHF contest a couple of weeks ago, and then again today.  It is working
again, but I am wondering if it is reaching the end of its life.  I have
been rotating it much more recently as I have been playing on the satellites
again and have to move the antennas to follow the sats.

So what can one expect as to the useful life of these rotors?  Is it time to
replace it or is something else likely going wrong with it?


73s John AA5JG
(ex: W5TD, NE0P)
6M WAS #1275, 6m VUCC #1260
2m VUCC #615, Satellite VUCC #129