[TowerTalk] 2"OD tubing inside a Rohn 25AG2

[Mark Robinson]

.
>>>
> Darn! I went back though the thread looking for that but didn't find it.
> Yes, I agree if he has it phrased that way.  I have a long extension
> above the top of the tower with the big array on it on 45G, but I'd not
> recommend it for 45G let alone for 25G.  Phrased that way I'd agree with
> the phrase,  Don't use tube where you can use tower.
>
> I'm removing the 144/440 antennas from the array, not because the system
> won't hold them, it has now for over 8 years and in winds gusting to
> over 70, but it's beating the snot out of those antennas.  As I've said
> before, those VHF/UHF antennas look like they are on a Blue Gill fly rod
> that just tied into a big bass.
>
> 73
>
> Roger (K8RI)
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


Here is his original post


quote"

I have 3 sections of 25G, the top being a 25AG2.  I would like to use a
12' piece of 2" OD .25" wall 6061-T6 aluminum tubing to get a total
height of around 40'.  The antenna will be a 2E Steppir.  My question
concerns running the aluminum tubing through the top of the 25AG2.  Is
this a reasonable application?  Can I expect a lot of wear on the tubing
when not using a thrust bearing?  Will there be sufficient support for
the tubing in the rotator (a HAM IV)?

Thanks and 73,

Tom K7TBM


"end quote




So our advice is - buy an extra 10 foot secton of Rohn 25 and use a short 
mast section to support your Steppir. This will get you 40 foot plus and be 
much stronger.

Mark N1UK