[TowerTalk] 43 feet pole for vertical

[K8RI]

On 11/1/2012 7:03 AM, Pete Smith N4ZR wrote:
> There *is* no such thing as simple trig, if your last brush with a
> cosine was 56 years ago!

I have to confess it's not been quite that long, but I'm only 72. <:-))
Actually I never took trig, which is quite a trick because I have a math 
minor.  Try Calc II without ever having had trig.  That was truly a self 
taught crash course in trig. <LOL>  And yes, I have to get out the book 
and look up the functions "just to be sure"...Now Derivatives and 
Integrals are something else. It'd take a few weeks review there.  They 
told me I needed Calc.  The last time I used it professionally ... was 
in school. Never did need it for work.

73

Roger (K8RI)

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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>>
>>
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