[TowerTalk] 43 feet pole for vertical

[K8RI]

On 11/1/2012 8:28 AM, Gene Fuller wrote:
> For anyone who is "trig challenged",, pencil, paper and a ruler and
> using about 8 feet to an inch (i.e.1/8th of an inch to a foot) would
> probably work out close enough. Anyway, trig wouldn't allow for any
> (though minimal ins this case) sag and wanting to throw in a little
> extra for tieoff and handling.

That's why I like synthetic guys.  They weigh so little the catenary is 
very shallow.

73

Roger (K8RI)


> Gene / W2LU
>
> ----- Original Message ----- From: "Pete Smith N4ZR" <n4zr at contesting.com>
> To: <towertalk at contesting.com>
> Sent: Thursday, November 01, 2012 7:03 AM
> Subject: Re: [TowerTalk] 43 feet pole for vertical
>
>
>> There *is* no such thing as simple trig, if your last brush with a
>> cosine was 56 years ago!  Fortunately, you can back this one out with
>> the old hypotenuse formula.  Even I remember how to do that.
>>
>> 73, Pete N4ZR
>> The Reverse Beacon Network at http://reversebeacon.net, blog at
>> reversebeacon.blogspot.com,
>> spots at telnet.reversebeacon.net, port 7000 and
>> arcluster.reversebeacon.net, port 7000
>>
>> On 11/1/2012 3:35 AM, K8RI wrote:
>>> On 10/31/2012 11:00 PM, Hans Hammarquist wrote:
>>>> I was wondering if someone has experience with a 43 foot vertical,
>>>> mounted on top of a
>>>
>>> tower. I used one before on top of my roof, but that one was
>>> supported with simple guy wires.
>>>
>>>  Needless to say that is not easy to do if I put it on top of my
>>> tower (85 feet tall).
>>>
>>> Any suggestion? Maybe it is a very stupid idea?
>>>
>>> Guying at 80 feet is almost as simple as guying when on the roof. I
>>> assume the tower is solid so use the same anchor points on the
>>> vertical as you would on the roof. It's just the ground guy anchor
>>> points have to be farther out.
>>>
>>> It only takes some simple trig to calculate the length of the guys
>>> assuming the yard is farily close to level.  Use single or doubly
>>> braid poly.  1/8" is strong enough to anchor about 3/4 the way up the
>>> antenna.
>>>
>>> If the tower is 80 feet and the antenna is 43 then 2/3rds of 43 is
>>> roughly 28.6 feet (give or take a foot or two) So the height is 80 +
>>> 28.8 is 108 feet.  If the distance from the tower to the guy anchor
>>> is 80 feet then sqrt(108^2 + 80^2) and I don't have a calculator in
>>> there to run that last square root.
>>>
>>> I'd use double braided poly on the vertical and probably Phyllistran
>>> on the tower. However I think the 43 foot vertical is going to need
>>> radials so I'd use steel for those.  I've done that with a 40 tower
>>> and 33 foot vertical and it worked just fine. I only used 4 radials
>>> but was pleased with the results. Course that was back in the late
>>> 60's until about 1980.
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>>
>>>
>>>
>>>>
>>>>
>>>> Hans - N2JFS
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