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Re: [TowerTalk] Hy-Gain AV-640

To: tower Talk <towertalk@contesting.com>
Subject: Re: [TowerTalk] Hy-Gain AV-640
From: Bob Nielsen <n7xy@clearwire.net>
Date: Sun, 28 Dec 2008 16:31:14 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On Dec 28, 2008, at 3:23 PM, Richards wrote:

> I have yet to install my AV-640 which remains in the box  -- I am
> STILL all unsure, worried, and obsessing over how I can install
> it over the front corner of my attached garage or other location
> in the yard.  (I have a big 43 foot monopole vertical in the middle
> of the back yard...) and have been considering:
>
> 1)  20 feet of RG type lightweight tower (e.g. two sections)
>       braced against the house/rafters/eaves
>
> 2)  A twenty foot  1.75 inch heavy galvanized iron water pipe,
>       set in a couple feet of concrete at the base, and  braced
>       against the house/rafters/eaves
>
> 3)  a 3-5 foot roof tower and 5-foot mast set in the middle of
>       the garage roof.    (Wife does not favor holes in the roof...
>       but is OK with options 1 and 2 - but will not cry about this
>       option if it is best and can be done safely and securely -
>       and I share these concerns... especially after the 50 mph
>       wind storm last night that shook the house all night....)
>
> 4)   A ten to 15 foot 2-inch galvanized water pipe set somewhere
>       in the yard far enough away from the house and the big
>       vertical in the back yard... I can put it AT MOST about 50
>       feet from the big vertical if I put it in a corner of the back
>       yard, but I have rather narrow side yards (avg sized
>       suburban lot)
>
> 5)    ????  (Any other options I should consider...)

I essentially used your option #2, although I picked a shorter piece  
of pipe for two reasons; the ability to easily mount the antenna  
while standing on my roof and getting it home from the hardware store  
without a truck.  I have two feet of it set in the ground (no  
concrete) and two straps 90 degrees apart tying it to the an inside  
corner of the fascia (no guys, or room for them).  I have had no wind  
problems, although I live in a fairly protected area and the maximum  
speed has probably not exceeded 50 mph.  Hy-Gain packed some  
incorrect mounting hardware so I made up a plate using muffler clamps  
to tie it to the pipe (if I had to do it over, I would have used  
galvanized U-bolts instead).

>
> ISSUE = How to mount it so it can tip down and I can access
> it for tuning?    Can I stand on the roof to tune it if it can be
> tipped over on the mast or tower section?

I set mine on a 10 ft pipe clamped to a sawhorse for tuning.  After  
moving it to the pipe mast I rechecked the VSWR at the antenna and  
the shift was minimal so I ignored it.  The internal tuner on my  
TS570 easily matches it (feed line is ~75 feet of RG-8X).

>
> ISSUE = How high must it be over the roof (and gutters) if I
> brace it against the side of the garage?   How much do the
> counterpoise radials droop  (and can I suspend them
> with light rope to keep them from drooping without causing
> a wind loading or other problem?

The counterpoise droops less than two feet.  One of the wires is  
maybe a foot above the slope of the roof.  Again, wind hasn't been a  
problem.

>
> ISSUE = How should I guy it if I mount it over the roof
> (and gutters) if I brace it against the side of the garage?
> I can tie off to the garage sides and roof on three sides
> of it, but then the side away from the house/garage needs
> something... or does it?   Are three quarters sufficient?
> Does not seem balanced that way.    Again, I have a narrow
> side yard and do not want a problem with the neighbor kids
> or lawn mower service...   I do not have quite the space Roger
> has for guys... DO I NEED TO GUY IT... really?   (Yeah... I know
> an ounce of prevention...)
>
> ANY IDEAS GREATLY APPRECIATED.   I WOULD LIKE TO GET
> THIS UP SOON...
>
> I admit to obsessing, but my big vertical sustained 60 mph winds
> last night with no problems, so I am 1) able to finish the project
> if assured by good plans, and 2) get good results by good
> planning.

Always a good idea!

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