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@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@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@kk9a.com>
>>Subject: [TowerTalk] Plastic End Caps
>>To: <TOWERTALK@contesting.com>
>>Cc: bmaser@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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>
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