[TowerTalk] Hi Gain Hi-Towers

[TexasRF at aol.com]

Wayne, have you done a stress analysis of the stinger? You should be able  
to use one of the yagi stress programs to do that.
 
If you think about it, your 44ft stinger is similar to one half of an 88ft  
long yagi element. That is not a trivial size; quite a bit longer than a 
full  sized 40m element for example.
 
It is not unusual to see a full sized 40m element that is 2 to 2.5" OD at  
the center and 1/4" wall thickness.
 
Since the stinger is much closer to the ground than a typical 40m beam,  
there will be somewhat less wind exposure. It seems logical that there would 
be  no need for wind survival greater than 70 mph but it depends greatly on 
how  exposed the stinger is to the wind. A few trees or buildings in the 
vicinity  would help with wind exposure. Sitting at the top of a nice hill and 
in the  clear, then full exposure should be expected.
 
A possible solution is adding some guys to the stinger. Some 1200 pound  
rated Phillystran would serve well for that.
 
Hope this helps resolve your problem.
 
73,
Gerald K5GW
 
 
 
 
 
 
In a message dated 12/19/2012 9:09:41 A.M. Central Standard Time,  
w3ea at hotmail.com writes:







Hi Roger

The  small  24'  BX style towers are not the failure Point. it's the 44' 
stinger  that's the area of failure !
Another friend who's of the DX- Expedition  type suggested I opt for  the 
tapered  fiberglass poles. !  

Still trying to model or see why the insulated  stinger at the  top of the 
tower has such a remarkable effect ?

Wayne W3EA

( I  am sorry for the post, I am not able to get  word  wraparound to  
function on this  reflector ! )  

> From:  K8RI-on-TowerTalk at tm.net
> To: towertalk at contesting.com
> Date:  Wed, 19 Dec 2012 08:52:36 -0500
> Subject: Re: [TowerTalk] Hi Gain Hi  Tower ??
> 
> 
> Why not guy them with phillystran or poly  rope?
> 
> 73
> 
> Roger K8RI
> 
>  ----------------------------------------
>  From: "Wayne Kline"  <w3ea at hotmail.com>
> Sent: Sunday, December 16, 2012 9:28  PM
> To: "towertalk at contesting.com"  <towertalk at contesting.com>
> Subject: [TowerTalk] Hi Gain Hi Tower  ??
> 
> Hi fellow Tower Talkers.. . I built a 75/80 meter Four Sq,  antenna 
system 
> many years ago. It was feed with an original DX eng. (  not the new Dx 
eng 
> co.) quadature. The  Hi Gain Hi towers were  stripped of everything and a 
> center  stinger was  built  and   the system was resonantat 3.625 MHZ and 
> the power  dump at 3.500 was 70 watts and at 3.825 was 100 watts.  I used 
>  the two insulators at the two stinger vertical element with a 14ga wire  
> attached at it's bottom and  travel down the inside of the 24ft  base 
tower 
> attaching at the feed point. There are 108 evenly spaced  1/4 radials 
under 
> each antenna, with silver soldered connections at  there interesting 8ga 
> copper X and 9-  8 ft  5/8" ground  rods.  One at each tower base, one at 
> the control box in the  center  of the array and 4 at the end of the 
> centered X wire.I  had a few 80 meter ops who felt that because I 
insulated 
> the top 38'  stinger  at the top of the tower resulting in a Shorter over 
>  hight antenna was a compromise.    So I 
> got in touch with  tim K3LR knowing he also had a 75/80 meter 4 SQ mad 
out 
> of Hi-Gain Hi  Towers, He sent me a rough dimension of his stinger out 
the 
> top of  his Hi-Tower. I  un insulated the stinger  and built my  elements 
 
> and achieved resonance with an additional 9ft  height.Well it seemed My 
WX 
> in eastern PA did not like the 48'  stinger  and I would loose one at 
almost 
> every  Nor'easter  Storm.      SO I am thinking of going back to the 
>  original configuration with insulated  top 2" tuber and the 14 ga wire  
down 
> the center of the tower to the base.  Thought's out  there  Just kicking  
> around  ideas ? Wayne  W3EA                     
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