[TowerTalk] Do I need an insulator on the ends of my

Jim Thomson jim.thom at telus.net
Sat Jun 27 11:19:49 EDT 2020


Date: Fri, 26 Jun 2020 21:33:25 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Do I need an insulator on the ends of my
dipole?

On 6/26/2020 11:07 AM, Kevin Zembower via TowerTalk wrote:
> Why do I need an insulator?

<Because the open end of an antenna is a high voltage point, and when the 
<rope that holds it is wet, the RF can melt it and the antenna will fall 
<down. Ask me how I know. :)  If instead it's connected to an insulated 
<wire, because it's a high voltage point, the insulation can arc over to 
<the wire. The same is true of radials.

<73, Jim K9YC

##  Does anybody know what the  EXACT  peak voltage is....on the ends of a half wave dipole,
say with  exactly 1000  watts cxr  applied  to the feedpoint ???   Say a 80m dipole up  100  ft... flat swr, fed with coax +  CM choke.

##  what is peak Voltage at various points  along the dipole ??   again with 1 kw cxr applied.  What happens to peak  V  along the  dipole as swr is increased ? 

##  I would have thought  rain water  was distilled  water,  high resistance... but have never  tested  rain water.
Have tested  store bought distilled water..and   then compared distilled water to  tap water....  huge difference.

##  I suspect  dacron rope, when wet, is not much better than nylon rope. 

Jim   VE7RF



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