On 12/31/12 01:16 am, Larry Loen wrote:
As many of you may remember, I have this (still) extended adventure going
to put up my tower (a US Tower HDX 572MD). The tower is actually standing
up, but, given I can only work on it during weekends, the "finish" work is
taking forever.
One of the next steps, though, is to design something that sits at the
"base" to receive the coax as it coils up.
The design of the tower that I have (unlike the former one at W0IBM that I
generally take as my model) has its "stand off" arms all in alignment. We
discussed whether I should let the coax fall all the way "in line" or try
to affix it to each arm.
US Towers said that hams did both, but I really don't see an easy way to
prevent the coax from "snagging" on the lower arms after lowering it. So,
the "fall through" approach seems prefered.
However, with the tilt over fixture in-place (or even if it is not), I seem
to require some sort of "tub" to receive the coax when I lower the tower or
partially lower it.
The most obvious choice is a circular tub, mounted on metal or perhaps 4x4
inch wooden legs (maybe even with plywood reinforcement under the tub's
bottom.
I see an ad here:
http://tsc.tractorsupply.com/tractor/Plastic-Tubs?reqUrl=http%3A%2F%2Ftsc.tractorsupply.com%2Ftractor%2FPlastic-Tubs&storeId=10551&zoneMarketInfo=2-45&storeZip=85138&storeCity=city%2C+state&catalogId=10001&langId=-1
. . .showing an open, 25 gallon tub with a 14 inch diameter suitable for
watering horses. Is this the sort of thing I should be looking at? Do I
need smething bigger? I expect to have two or three coaxes (9913F type)
plus some control cable (at least six eighteen gauge and two fourteen
gauge) going up the tower with the coax. I assume I tape the control lines
to a coax and maybe the coaxes together.
I also seem to want to put in some sort of gadget at the top so that I can
provide some sort of "rounded 'L' material at the very top to provide some
strain relief for the coax which otherwise would bear the weight of a 72
foot drop at one point. That seems a problem, especially in the 120 degree
Arizona sun.
I'm not totally thrilled with this, but I don't see a good alternative
design because I don't see how to avoid the snagging issue. I'd rather
attach everything to each extended arm, but haven't figured out how to make
it really work reliably when the tower is anywhere near fully collapsed.
I use a large RubberMaid trash bin (from Sam's Club) -- "Brute" is the
name that comes to mind -- with a slot cut in the lid, through which I
guide the coax as the tower comes down; I realized later that I could
have got a lid with a central round hole, which *might* have been better.
73
Alan NV8A
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|