[TowerTalk] Thrust bearing question

[Jon Pearl - W4ABC]

Hi Gene.


I see you're not too far from Jeff, W2FU.  I'll be turning the new 
OR2800 with one of his controllers.  I'm pretty excited about that!

Thanks for taking the time to do the initial work-up for me and then to 
further go back and give it a second look.  I appreciate the time you 
took to look into the issue for me by plugging in some numbers that are 
very close to my real world situation.

While I'm probably never going to have to worry about ice, the winds can 
cause some havoc here in Florida from time to time.  It was twenty years 
ago - almost to the month that I suffered a catastrophic 3" boom 
collapse to my 4 el. Cubex quad during one giant wind gust that I 
seriously thought was going to take the roof off.  I got up the next 
morning, never thinking to look at the tower.  It was still dark out and 
I was happy to be driving 90 miles to the north to the Orlando Hamfest.  
The No Name Storm http://www2.sptimes.com/Weather/SW.3.html had taken 
out my boom, overnight.  Not until I got to the hamfest did I receive 
notice from one of my late arriving friends that he'd received a phone 
call from my wife and been to my house to survey the damage.  Half the 
boom was still held up in the air by its truss line.  The other, not so 
much.

In 39 years as a ham, prior to owning this new KT-36XA I've only ever 
owned bamboo and fiberglass cubical quads.  While three dimensional in 
nature, they're also very forgiving of the wind.


Thanks again, Gene for performing due diligence for me.


73,


Jon Pearl - W4ABC
www.w4abc.com




On 2/7/2013 9:22 PM, Gene Fuller wrote:
> Correction to my previous re mast loading. I think my mind was on 
> vacation. Clearly, 18 x 4 = 72, not 64. Therefore in the example shown 
> there is room for another 8x worth of antenna. e.g. 1 more sq ft on 
> the tribander at 1 foot up and 1 more sq ft on the 6 meter at 7 feet 
> up, with still a little room for ice or whatever.  Sorry, again, about 
> that.
>
> The "Economy of space" may well be in not having to replace the mast 
> and perhaps one or more of the antennas after the first medium wind 
> storm. Being a bit conservative in the design sure helps you sleep a 
> lot better on those windy nights.
>
> Gene / W2LU
>