On 12/17/2011 5:17 AM, Paul_group wrote:
> On 17/12/2011 10:03, K8RI wrote:
>> On 12/17/2011 3:44 AM, Ian White GM3SEK wrote:
>>> Watch out for PST rotators in a tilt-over tower, because the water
>>> shield over the top seal is only fully effective while the tower is
>>> upright. If the tower is routinely tilted over for storms, it is
>>> advisable to protect the rotator from driving rain.
>> If you lay it over so the output shaft is horizontal any water that gets
>> in should run right back out. I'd be more concerned about driving rain
>> and wind with the thing upright. If water can still be trapped under
>> that cover it could still suffer from the old problems.
> Not so Roger, if the unit is on its side water can and will get into the
> top bearing,
Mine has a seal up there. The only reason water is a problem is the top
of the rotator has a raised rim around the area of the top seal. That
rim which is a reinforcement is about 4" in diameter and presents an
area where water can collect. The water can not get into the bearings
regardless of the position of the rotator.
What happens if if the water sets there long enough for the output shaft
to rust, then and only then will the top seal be compromised.
See photos 12, 26 and on. http://www.rogerhalstead.com/Gears.htm Photos
12 shows the top plate with the seal in place and the ridge around it.
Actually there are two ridges that have the bolt circle between them.
> Like most rotors they are only intended to shed water.
> Water can also get through the mild steel plate / rotor housing
> interface on the bottom. The pot is vulnerable in these circumstances.
Again, the bottom also has a seal. The pot is actually outside the
rotator housing and yes the pot is vulnerable but not very. The rotator
would have to be "stored" upside down for water to be a problem in that
case. See photo 21.
> If the unit is used on a tiltover tower its worth spacing the rotor off
> the plate by a few mm to allow drainage and using a temporary cover to
> protect everything when horizontal, a plastic fertilizer bag works well.
Having used one for quite a few years I'd not be very concerned about
having to "bag" the rotator. Unlike the Ham series rotators, they are
not open to water ingress.
The old ones do rust if water sets in that recess. The rust tears up the
top seal, and that is what does the damage. See photos 1 through 4. 4
shows the deeply pitted shaft due to water sitting in that recess,
after having been cleaned
>
> And yes it was a very good suggestion to improve the paint coating, well
> worth ten minutes of prevention.
>
>
>
73
Roger (K8RI)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|