[TowerTalk] Thrust bearing for AB-577??

[Pete Smith N4ZR]

That's true, Joe - the thing that concerned people was the 6-foot lever 
arm above the tri-bander, even though the antenna mounted at the top of 
it is quite small.

73, Pete N4ZR

On 7/18/2023 11:05 AM, Joe Subich, W4TV wrote:
>
> Yaesu show a mast bearing - mount to the mast above the rotator and
> guy - but with your relatively small load I don't see a need for it.
>
> Look at the loads K7NV had on his AB-577(s) with no bearing above the
> rotator.  His TH7 represents significantly more load that you are
> proposing.
>
> 73,
>
>    ... Joe, W4TV
>
> On 7/18/2023 9:41 AM, Pete Smith N4ZR wrote:
>> I have a C-3E tribander on an AB-577 "rocket launcher."  I also have 
>> a 3-element 6-meter yagi that I was planning to mount 6 feet above 
>> the Yaesu rotator at the top of the 577, but was deterred by concern 
>> of some knowledgeable hams that this might overload the rotator and 
>> cause a catastrophic failure, destroying the rotator and the 
>> tribander. That's just too big a risk for me.
>>
>> It occurs to me to wonder whether someone out there has contrived a 
>> way to mount a thrust bearing above the rotator on an AB-577?  I can 
>> visualize what this might look like, involving a structure attached 
>> to the top of the top-most tube below the rotator and supporting a 
>> thrust bearing a foot or so above, but don't want to reinvent the 
>> wheel unless necessary.
>>