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Re: [TowerTalk] Frestanding Dipole Support - inexpensive

Subject: Re: [TowerTalk] Frestanding Dipole Support - inexpensive
From: K8RI <>
Date: Mon, 12 Dec 2011 21:39:19 -0500
List-post: <">>
On 12/12/2011 11:57 AM, Ken wrote:
> Scotty,
> If the wood fence has good solid wood posts, you can tie a 10 or 20 ft mast 
> to it.   If  you can find 20' sections of pipe or chain link fence top rail, 
> that's great.  I can't find that around here any more but what I am currently 
> using is two ten foot sections of 1-1/2&  1-3/4" conduit that slip inside 
> each other for a decent 19 foot mast.  I just have it tied with rope to a 
> sturdy fence post.
You are not likely to get 19' of mast that is free standing and hold the 
end of a 160 dipole. Unless the loaded dipole is light weight and under 
little tension the top of the mast will need to be back guyed. You 
really need about 3' of overlap.

NVIS?  Well... I have (in the past) used what I called a droopy dipole 
40' high at the center and used both 10 and 20 foot elevation at the 
ends.  The extra 10 feet made a big difference, but the antenna covered 
typically about half the US.  Staying up late and perseverance 
*eventually* did get me most of the Western states from Michigan. I did 
work a few countries too, but it was a struggle for anything much over 
about 1200 miles.

> Alternately you could dig a new post hole and set a 16' pressure treated 4x4 
> in the hole ($17 at Lowes).   Rig an eye and/or pulley at the top before you 
> erect it.
The 4 X 4 has a lot of possibilities although I'd set it deep as 
possible and a minimum of 6'.   With the EMT that would give you at 
least 10' of support and the ability to maybe move the mast up another 
5'.  With 3' of overlap for 17' + 5' you might get 22' of support 
"unguyed" as long as you don't pull on it too hard.  You might consider 
1 3/4" inside 2" as it would be stronger.

"In the old days" we'd have used a couple of pieces of galvanized water 
pipe telescoped but that stuff has gotten expensive and it's not strong. 
In addition it's heavy and easily bent, but for something like this you 
could have easily gotten 30-35 feet. It would have been like a wet 
noodle but with 10' of 4 X 4 at the base it most likely would have done 
well, except in high winds.   If 20' is sufficient then how about the 
4X4 anchor and a single length of 1 1/2" pipe for a mast? The problem is 
cost and that keeps bringing us back to a couple pieces of EMT.

Another approach would be to build a small triangular, self supporting 
mast out of 16' 2 X 4's using the 4 X 4 as an anchor.  Of course 2 X 4's 
aren't terribly strong,  but they are stronger than the EMT we've been 
talking about.  You could scale it as a small tower and could probably 
get 30 feet out of it.  Unfortunately we're back to pushing the cost up.

Still the EMT and 4 X 4 would be the most bang for the buck even if the 
EMT pieces are not a snug "slip fit"

> Ken WA8JXM
> On Dec 12, 2011, at 11:08 AM, Rick Scott wrote:
>> I have a limited lot and want to try to put up a 160 loaded Dipole I have.
You moved back into town?
>>   In the front of the lot I have a 35-40 tree I can use (Yes I know NVIS, 
>> But only looking at 160m States) but in the back I have nothing to hold up 
>> the other end with.  I have a Chain link meeting a Wood fence back there, 
>> but what ever I use must be free standing.  Dont think it has to be that 
>> high maybe 20ft or so.
>> I have a 25ft Push up flag pole in the front yard that would be ideal. It 
>> holds a 4x6 flag  really well even with the huge winds we had recently. 
>> However, I dont think the wife would like me moving it to the back yard.  
>> Plus the expense precludes me getting another one, after the 746pro and the 
>> steppir the ham budget is spent :).
I have all my antennas down for maintenance except for the 40 and 80 
meter wire antennas, plus a Hy-Gain AV640 which does surprisingly well 
on 40.  Time I get on it's too late for the other bands, but I was 
hearing VKs last night around 3 AM.  The antennas are ready to go back 
up, but the Doc won't let me climb for the time being and I don't like 
the liability of a non professional climber going up either tower.

I assume you are talking about the Stepper vertical?
>> So Im down to asking for ideas of what i could use thats
>> A. easy to assemble
>> B. Relatively Cheap.
>> Ideas to ponder are welcome
Good Luck,

Roger (K8RI)


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