Joe Giacobello wrote:
> I have stayed out of this discussion because things mechanical are not
> my strong suit, and I have had my share of rotor problems lately. At
> any rate, several months ago I had a discussion with Craig, the owner of
> the C.A.T.S. rotor repair service, regrading the suitability of the Ham
> series and the T2X for turning big antennas. According to Craig, if you
> don't try to turn the T2X in heavy winds, its brake can withstand the
> stresses. It's only when you release the brake and allow the stresses
> to act directly on the gears that you may suffer damage in high winds.
>
I think that is basically what I've been saying. But as to detail the
gears in the Ham series of rotators as well as some of the Yaesu
rotators I've seen are very thin, stamped steel. They uses a series of
spur gears to get the motor speed down to something usable with enough
torque to turn an antenna. Those gears are fragile. (cheap is a better
and more accurate description) On top of that the brake design was
designed to hold, not stop rotation. When it's windy and particularly
if the wind aids the rotation the forces exerted on the bell housing are
tremendous when that wedge drops in place.
Any one ever hear those gears "sing" when being driven by the rotation
instead of the motor? <:-))
Due to the relatively low cost and wide availability both new and used,
the Ham series of rotators (which are basically good rotators within
their design parameters) are probably the most abused rotators in use.
73
Roger (K8RI - ARRL Life Member)
www.rogerhalstead.com
> He also went on to say that there was relatively little difference in
> the ruggedness and turning capacity between the T2X and the Ham Series
> (II, III, IV) of rotors for inside the tower installations. The T2X,
> because of its mechanical construction, provides a more rugged
> installation for mast mounted rotors, but they're all about equivalent
> when mounted inside the tower.
>
> FWIW and YMMV.
>
> 73, Joe
> K2XX
>
> Rob Frohne wrote:
>
>> Hi Roger, et. al.,
>>
>> When the wind really blows, I hold the brake down and let the antenna
>> rotate by turning the motor to the direction it wishes to be. I then
>> release the brake lever so the brake is re-engaged. That way the
>> antenna doesn't tend to more than swing back and forth a quarter of a
>> turn or so if the mast rotates in the rotor, and I can recalibrate it
>> without climbing the tower (using the adjustment on the rotor control
>> box).
>>
>> 73,
>>
>> Rob, KL7NA
>>
>> On Thu, 2008-06-05 at 12:51 -0400, Roger (K8RI) wrote:
>>
>>
>>
>>>>
>>>>
>>>>
>>> Having used to old Ham series on antennas as large as full size KLM 5L
>>> 20 meter and 6 L 15 meter antennas (42 foot booms) I'd add
>>> two points: Don't use the rotator when the wind is strong.
>>>
>>> If necessary (as a last resort) use the motor to stop/slowdown one if
>>> you discover the wind is causing it to turn or even accelerate when the
>>> brake is released. Although hard on the motor, it can handle this sort
>>> of thing on an intermittent basis and do so much better than the brake
>>> or stops. Just don't do it often, or for more than a couple of
>>> seconds. IE. Hit reverse and then engage the brake. Even a momentary
>>> pause will allow the brake to engage without tearing things up.
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>>
>>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|