On 1/13/2012 9:43 AM, Jim Thomson wrote:
> Date: Wed, 11 Jan 2012 07:45:02 -0500 (EST)
> From: HansLG@aol.com
> Subject: [TowerTalk] Fwd: How to get another 10' in height? Add a mast
> or add an...
> You only have to climb a tower once to know that you want as little as
> possible "complications" once you are "up there". Also, it is not the top of
> the tower that is exposed to stress, it's the bottom. The tower section
> "below" have to take the mechanical stress from whatever is above. That's the
> reason you design the tower from top-down.
> Design the tower for the height you need and don't plan to add anything
> Hans - N2JFS
> // a buddy installed 190 feet of rohn 55 g... with 4 x sets of KX0G rings.
> The entire
> tower rotates. I discovered that Rohn makes these super heavy duty versions
> of 45, 55, 65 G.
> They are not only Z braced, they are also X braced.
I believe they also make, or did make, solid leg versions. Now those are
> He used 3 of the super heavy duty sections
> for the top 3 x sections of the tower. The very top guy ring was at 175
> feet. So he has 25`feet of
> unsupported tower above the top ring. A 2-el 80m yagi is at the very top of
> the tower. 4-el 40m yagi
> below that..and a 5-el 20m yagi below that..all in that 25 foot unsupported
> section . Each of the
> heavy duty sections costs a bit more..and also weighs a bit more. They are
> VERY strong sections.
> One helluva lot stronger than a stock 45,55,65 section. We also looked at
> using 65G. My problem with
> 65g was each step is 18 inchs... vs 15 inchs on 45G, and 55G. With
> horizontal steps being 18 inchs
> apart, that makes climbing tougher to say the least. Once 55G was decided
> on, the next step was to
> figure out how much unsupported tower can be above the top ring. The 3 x
> new guy anchors are out aprx
> 175`feet. The re-enforced X + Z braced stuff for the top 3 x sections fit
> the bill perfectly. So far, so good.
> The same tower supports 1 x 80m yagi, 2 x 40m yagi`s.... 3 x 20m yagi`s..
> and a single yagi for 17,15,12,10,6m.
> So x 11 yagi`s in total.
> later.... Jim VE7RF
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