[TowerTalk] Plastic End Caps

[K4SAV]

While I was waiting for my tower to be finished, my XM240 was sitting 
out in the back yard on concrete blocks for about a month.  When I 
removed the end caps, a whole bunch of water flowed out.  Draw your own 
conclusions.

Jerry, K4SAV

john at kk9a.com wrote:

>I agree that water inside a tube can freeze and cause it to fracture.  On 
>all of my antennas the horizontal elements are open at each end so water 
>does not build up, freeze and crack the tubing.  It seems to me that a cap 
>would seal in the water.
>
>John KK9A
>
>
>To: TOWERTALK at contesting.com
>Subject: Re: [TowerTalk] Plastic End Caps
>From: "Jeff Carter"
>Date: Mon, 21 Apr 2008 17:35:19 -0400
>
>
>In the case of the Cushcraft R7, moisture ingress into the traps
>equals VSWR of 10:1 or worse.  In the case of the A4S, insect nesting
>and moisture can cause issues.  With both antennas, water in the
>tubing can freeze in the colder months and the aluminum tubing can and
>will deform and/or burst from the pressure, just like a copper water
>line might.
>
>This may not be an issue at all QTH's, but at mine, antennas made with
>hollow tubing must be sealed against the environment.  Your mileage
>may vary.
>
>When purchasing end caps, be sure to deal with a vendor that does
>*not* charge a minimum order fee.  The one I suggested was selected
>for this very reason, all the others I've seen suggested will charge
>you anywhere from $15 to $25 for the privilege of taking your order.
>I would rather have something more tangible for my money since I am
>not wealthy.  Those of you who are, be my guest.
>
>Jeff/KD4RBG
>
>---- Original message ----
>  
>
>>Date: Mon, 21 Apr 2008 17:12:07 -0400
>>From: <john at kk9a.com>
>>Subject: [TowerTalk]  Plastic End Caps
>>To: <TOWERTALK at contesting.com>
>>Cc: bmaser at tampabay.rr.com
>>
>>What is the purpose of end caps?    I never use them and I have never had a
>>problem as a result of not having end caps.
>>
>>John KK9A 
>>    
>>
>
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