[TowerTalk] Any thoughts on spider-beams?

[Joe Subich, W4TV]

 > Why is this?  Is it related to having a boom truss?

Yes, the Spiderbeam has something like six "boom trusses" on
top, four on the bottom and four going spreader to spreader
to hold the "booms" square.  When you add something like
10 (for the 20/15/10 meter version) to 15 wire elements (for
the 20/17/15/12/10 meter antenna) the thing is a real
"spierweb".

With the "booms" extending 32' front to back and side to side
for 20-10 and 40'+ for the 30,17,12 "WARC" version, the trusses
need to be at least 3-4' above/below the booms to be even
marginally effective.

I suggest getting and reviewing the Spiderbeam Construction Guide
from their web site.

73,

    ... Joe, W4TV


On 7/18/2016 5:41 PM, Richard (Rick) Karlquist wrote:
>
>
> On 7/18/2016 1:02 PM, Joe Subich, W4TV wrote:
>
>> height of the AB-577 is about eight feet.  A Spiderbeam can not be
>> assembled on the ground and then lifted into place on top of the
>> rotator either.  I gave up on trying to install a 20-17-125-12-10 HD
>> Spiderbeam on my AB-577.  The only way one might make it work is to
>
> Why is this?  Is it related to having a boom truss?
>
> Rick N6RK
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