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[TowerTalk] Tower and Array

To: <>
Subject: [TowerTalk] Tower and Array
From: (K7LXC)
Date: Sun, 12 Apr 1998 11:11:38 EDT
In a message dated 98-04-12 09:32:16 EDT, writes:

> 1.  When I replaced the rotor about a year ago, I found that the
>  array is one heavy sucker.  It's also very tippy!  The mast at
>  the rotor got away from me (looking back, I have no earthly clue
>  as to why it was free and not secured in some way).  I think I
>  was very lucky in that the lower mast end was stopped by the leg
>  and leg rung.  However, I recall hearing the sound of rushing
>  water.  I looked down and my pants were dry, so I could only
>  conclude that the water was in the boom(s) of one or both of the
>  antennas.
>  We have end-caps on the booms.  Maybe we shouldn't.  I know N5RP
>  is (among other things) a propounder of no end-caps.   I'm
>  curious about this:  The element traps have drain holes.  Why not
>  the boom ends?  Is there any problem in doing so?  Has anyone
>  done it?  Would it be simpler to just leave the end caps off?  It
>  may be an opportunity for wasps/hornets, etc, to make homes in
>  the booms, but there are plenty of other openings on a tower that
>  they never set up residence in, so that may not be a factor.
>  Recommendations?

     I've run into water in the boom several times myself. It's the result of
condensation over the years. The water vapor gets in and condenses but the
water has nowhere to go so it starts filling up. It makes dealing with the
subject antenna a real pain since it's so out-of-balance. My choice is to
leave the end caps off or drill a couple of drain holes in them. 

      I haven't personally seen a wasp nest in a boom but ran into one that
engulfed one of the top sections of a BX tower. Boy - was THAT a surprise! It
was huge -about the size of a basketball. 
>  2.  The A3WS is about a foot above the tower top.  The A3S is at
>  the top of the mast.  Standing on the tower top, my hand reach is
>  about three or four feet short of the A3S.  Guess which antenna
>  needs service?
>  LIke I said above, I don't know what the mast is made of.  Is
>  there a way to tell by looking or some kind of scratch test or
>  something else to determine the hardness of the mast?  I can
>  probably measure the thickness of the wall at the rotor.  Given
>  the fact that the array has been up and on the mast for a number
>  of years with no problems, should I install a mast step and press
>  on to climb the mast and lower the A3S?

     Discretion is the better part of valor. If you're not sure, stay off of
it. Chances are that it's fine since thin-wall something or other would have
crumpled years ago. A static load like someone climbing on the mast for a
couple of feet is manageable by water pipe and other 'light duty' masts.

     If you can see the bottom of the mast at the bottom, that should tell the
>  As I was gassing up the car the other day, a large bucket truck
>  pulled in to gas up.  I asked them the extension of the bucket
>  and their rates and they said 70 feet and $68 and hour.  That
>  seems pretty reasonable to me.
>  With a bucket truck, we could have the antenna down in a couple
>  of minutes, check it out, maybe even fix whatever needed fixing,
>  and have it back up all within an hour.  The tower is located
>  directly adjacent to the employee recreation center parking lot,
>  so the truck's access to the tower shouldn't be a problem
>  Has anyone used a bucket truck to take down antennas?  

       But of course. My policy is why do it yourself or put yourself at risk
if you can get a piece of equipment to do it? This is true when you're not
sure about the safety factor like your unknown mast or when you do have a bent
mast and antennas or even tower. It's worth the cost for the added safety
factor. In my book, it's even cheap for the piece of mind.

Cheers,  Steve  K7LXC

      TOWER TECH -- professional tower supplies and services for amateurs

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