You will see the type failure Larry outlines if...
1. the two mounts are too close vertically and
2. there is too much mast above the upper mount.
Most of the wall mounts are intended to be used with a single ten foot mast
section. If you use more mast length then you have to increase the vertical
distance between mounts but about 15' of mast is the maximum (and since more
of it is below the roof line due to the increased mount distance, it adds
little over a single 10' mast). If you are using a "push-up" mast, you have
to go from ground up resulting in 3 support points (mast over pipe driven
into the ground, first wall mount mid-way up the wall, and upper wall mount
just below the roof overhang).
73 de Perry - K4PWO
----- Original Message -----
From: "Alan NV8A" <nv8a@att.net>
To: "TowerTalk" <TowerTalk@contesting.com>
Cc: "Larry Banks" <larryb.w1dyj@verizon.net>
Sent: Saturday, April 25, 2009 12:35 PM
Subject: Re: [TowerTalk] Advice requested --- Eave Mount
> I've had this arrangement on two houses and have never seen that
> problem. I assume that this kind of bracket comes with various
> thicknesses of metal. Mine came from Lentini in CT -- just down the
> street from ARRL -- and look pretty solid. They may be much more solid
> than what is sold for TV antennas. I have no idea of the brand.
>
> Alan NV8A
>
> On 04/25/09 11:45 am Larry Banks wrote:
>
>> My concern with a wall mount like these is that the moment arm is long
>> enough such that the mast and antenna could bend the two mounts sideways
>> in
>> opposite directions and lean over. I had that happen a long time ago
>> with a
>> similar mount. I assume you have not had this happen?
>
>>>> I am bringing up a second station at a 2nd home in Maine. My first rig
>>>> will be for 2M/440 FM, followed by HF.
>>>>
>>>> A question about mounting my FM "stick." I will be using a Diamond
>>>> X-510NA or equivalent (5 pounds, 17.2 feet long, rated for 90 MPH)
>>>> mounted at the eaves of the house. (Yes -- a small roof tower would be
>>>> a
>>>> better solution but for now that is not an option.)
>>>>
>>>> Searching the web turns up a number of Eave Mounts -- two examples are
>>>> the Radio Shack #15-0891 for $18 and the Thomas&Betts EM-48 at $25.
>>>> (There are many others, but they all are similar.) Tessco, naturally,
>>>> has many styles -- many of which are more robust than needed.
>>>>
>>>> Do any of you have experience with either of these? What other
>>>> suggestions might you have?
>
>>> For that antenna I used a pair of something more like the T&B wall
>>> mounts:
>>>
>>> http://www.tvantenna.com/products/tvreception/mounting/wallbrackets.html
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|