[TowerTalk] Re: First Tower questions

[Paul Playford]

----- Original Message ----- 
From: "Arthur Prewitt" <artprewitt at earthlink.net>
To: <towertalk at contesting.com>
Sent: Saturday, October 25, 2003 3:30 PM
Subject: [TowerTalk] Re: First Tower questions


> Hi All,
>
>
>
> I need some expert advice. I am about to put up an LM470, I have had it
for
> a while but it was just too hot here in AZ to work. You could not touch
the
> tower without getting 3d degree burns. It has cooled off and I have all
the
> necessary permits, so now is the time.
>
>

How about some amateur advice?

>
> I plan for the following antennas:
>
>
>
> AR270B 2 meter Vertical at the Top of mast (lightning rod?)
>
> 2 meter 7 element beam (horizontal)
>
> 6 Meter 3 element beam
>
> Triband beam 20/15/10 or maybe a small multi-band quad.
>
>
>
> I plan on using a Ham IV rotor mounted in the tower.
>
>
>
> My question is what I should use for a mast, Length, ID. What would be the
> best separation between the beams, which also determines the length of the
> mast? In which order should the beams be stacked? How much of the mast
> should be inside the tower or where should the rotor be in relation to the
> top of the tower.  Do I need to use a thrust bearing? How do you align the
> mast and the rotor and thrust bearing?
>

I believe pipe is measured by ID.  Stay away from pipe.  I use a 2"o.d. x
20' mast in my LM470.  My T2X rotator is perhaps 4 feet from the top of the
tower with a thrust bearing on top of the tower that supports the mast and
monoband 4 element yagis for 10, 15 & 20.  I aligned the thrust bearing by
rotating the mast (clamps loose on rotator) and adjusting the thrust bearing
so there is no mast to tower binding.  I suggest you use the longest mast
you can obtain because you will always wish you had.

>
>
> If I what to hang a low band inverted v (160/80) from the tower how do I
do
> that? Will that stress the cables?
>
>

Hanging wires from the tower will require those wires be loose when
raising/lowering and become a PITA.  I leave my tower down during the
monsoon season.  Where I see a problem is that the wire antennas will pull
the tower to one side or the other and during the raising/lowering will
cause a binding between sections which in turn may break a cable.  Normally
the LM470 sections will float on the cables and not apply any sideways force
between sections.

>
> To some of you experts these will sound like silly questions but this is
my
> first tower and I don't have a clue. Be gentle.
>
>
>
> 73, Art
>
> N4PT Tucson, AZ
>

de Paul, W8AEF

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