In article , (W3CQH) writes:
|
| wrote in message
| ...
| Dan,
| I think you may have answered one or two of your complaints. I
| also think you have had a couple of 'manufacturing defects' that the
| company really ought to fix.

Yeah, but somehow it didn't seem worth the bother. I was up on the tower
when I discovered the short-tapped mounting hole and of course at that
point it was easier to get a shorter bolt.

| Because of where you live, you are going to have corrosion problems
| no matter who makes your rotor.

Although the corrosion makes the rotors unappealing to work on I don't
think it was the cause of the failures.

| About the only simple means of
| reducing that corrosion problem is regular maintenance, more regular
| than 'normal'?

Perhaps, though I still wonder why the HAMM faired so much better. In
order to do any kind of regular maintenance I think I'd have to replace
the bolts that hold the case together with stainless in advance since
they rust in place very quickly.

| Two 'duds' in a row is sort of unusual.

Three duds...

| That tends to tell me that
| quality control may not be the 'best' in the woprld, or at least could
| be a little better. I'm sure they won't jump for joy with another
| complaint, but I certainly think I would complain if it were my rotor!

Yeah, again it just doesn't seem too productive. I'm sure they would
be happy to have me ship back the latest one and I could wait around for
a replacement with my tower down. (I put it up today.) I think I'd
rather look for an alternative product or revisit the HAMM which I still
have.

| Dan,
|
| Since you live so close to the ocean, you might want to try and coat (spray
| paint) the rotator assy with NEOPRENE PAINT. (This paint is waterproof &
| impervious to salt water & diesel fuel and you should be able to find it in
| either a well stocked hardware store or paint supply store).

I'm not sure how this would help in more than a cosmetic way. You understand
that the rotor is not sealed, right? There is a gap between the bottom of
the bell and the mounting plate. It points down so water shouldn't be
*flowing* in, but the insides are certainly exposed to the weather. The
only thing keeping the bearings from rusting is the grease, and the retainer
strip really can't insure that they are always fully coated. The more I
think about this the more I remember stainless bearings in the HAMM, though
it might have been an after-market modification.

| You also might want to coat any open antenna connectors as well as any
| coaxial connectors.

I've had good luck with a tight spiral wrap of ordinary vinyl tape. Just
took apart some connectors that had been up for more than a decade and
they were shiny as new. Lately I've also been filling the insides with
STUFF dielectric paste but I'm not sure this makes much difference.

Dan Lanciani
ddl@danlan.*com

Dan,
There's no 'fool proof' way of 'fixing' any rotor that doesn't mean
a lot of inconvenience in some way. Picking the most palatable
inconvenience is the 'trick'.
"Productive"? Uh, yeah, I agree with you, probably not very
productive, But I'd do that complaining anyway. Who knows, they
might really surprise you (and me ).
Which solution is the best? I have no idea.
- 'Doc

Beat the @#$ thing to death with a very large hammer. Productive?
No, but @#$ sure satisfying!

Howdy,

In the 70's I worked on a project developing dual use small
boat radar. We had a terrible time with bearing corrosion at
first.

You might want to try wash-out resistant grease intended for
boat trailer wheel hubs.

In the radar we eventually used Andok C which is no longer
manufactured. Nye developed Rheolube 374C as a replacement
for Andok C. Both are an NLGI Grade 4 grease,

McMaster-Carr has a good selection of stainless steel bearings
and they have ceramic balls for bearings I believe. I'd want
to play with those a bit first before putting them up on a
tower.


73,
Grumpy



ddl@danlan.*com (Dan Lanciani) wrote in
:

I've had good luck with a tight spiral wrap of ordinary vinyl tape.
Just took apart some connectors that had been up for more than a
decade and they were shiny as new. Lately I've also been filling the
insides with STUFF dielectric paste but I'm not sure this makes much
difference.

Dan Lanciani
ddl@danlan.*com

"Grumpy The Mule" wrote in message
...
Howdy,

In the 70's I worked on a project developing dual use small
boat radar. We had a terrible time with bearing corrosion at
first.

You might want to try wash-out resistant grease intended for
boat trailer wheel hubs.

Good advice.

McMaster-Carr has a good selection of stainless steel bearings
and they have ceramic balls for bearings I believe. I'd want
to play with those a bit first before putting them up on a
tower.

Most folks instantly think of stainless steels for corrosion protection.
However SS is not a particularly corrosion resistant material around salt
water. All commonly available grades of SS are subject to halogen
corrosion, i.e. chlorides in sea water. Before retirement I worked at
Eastman Chemical company in their research laboratories. They frequently
had to resort to rather exotic alloys, such as Hastelloy C-276, for
applications where halogens were involved. These alloys tend to be
extremely expensive and nearly impossible to machine.

I would suggest using lots of a good grease and frequent maintenance if your
rotor is exposed to salt air.

Barry WA4VZQ