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Re: re: counterweights



Hi Gene,

I am also thinking of that setup quite a long time ago.
My Setup will consist of:

2m cross yagi================ 12 feet ============70 cm cross yagi
(#of el not decided yet )                                               (#of
el no decided yet)

The 12 feet dish already there now, using dual band patch feed (will be
upgraded to triple band with additional 1269 L-band).

The use of 2m & 70cm cross yagi is for chasing LEO.
The 12 feet is mainly for AO-40.
 For Elevation angle, I am using the Actuator (very accurate, giving 7 pulse
per degree).
For azimuth, I am using Kenpro KR-600, not quite accurate (about 5 degree
resolution) but still usable.
The counter balance is not a big issue for my setup, as 12 feet dish is much
bulkier than both the cross yagi.

Please let me know if your project is finished.

73, Reinhard Sual - YB0KTQ

----- Original Message -----
From: "Gene Davies AA6NP" <aa6np@mind.net>
To: <amsat-bb@AMSAT.Org>
Sent: Friday, March 07, 2003 9:56 AM
Subject: [amsat-bb] re: counterweights


> Hi all,
> I have been experimenting with the mechanical
> aspects of my future satellite antenna installation....
>
> 40 ele 70 cm--------6 foot dish----------------22 ele 2 m
>
> on a 12 foot 1 1/2 fiberglass boom. * I tried using an
> off center mount on the yagi antennas to act as a partial
> counterweight for the dish, but this introduces a significant
> amount of twist in the boom.*  I think this twist will make
> final alignment of the array really difficult.
> I think, at least with this heavy set-up, that each yagi should be
> mounted at its own balance point, and a counterweight used
> to balance the dish. The only problem now is that the
> counterweight places the weight of the assembly way
> over the rotor's rating for vertical load.
>
>
>
>                                  6 foot dish
> 40 ele 70 cm---------elev rotor----------------22 ele 2 m
>                        "              *              "
>                        "              *              "
>                        "              *              "
>                        "              *              "
>                        " ============="
>                                       *
>                                       *
>                                       *
>                                    mast
>
> So I am adding this steel crossarm with vertical support arms to
> take most of the weight off the rotor. Each support can be
> shortened or lengthened for final adjustment, and the
> counterweights for the dish will nest right in-between the
> mast and the supports. I am going to try using an 1 1/2
> pvc tee for the support to crossboom bearings, and make the
> supports themselves out of 1" allthread or something.
>
> Gene
>
>
> snip>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> I first add the the antennas that will be either rear mounted like a
> rear mount yagi or dish antennas like the gridded 2.4 GHz antenna.
>
> Then I add the 2M  and 70cm yagi antennas, at either end, adjusting the
> position of the mast to boom clamp for front to rear balance.
> Same with the 1.2 GHz yagis.
>
> for side to side balance (because the 2M cross pol is heavier than the
> 70cm cross pol,) I adjust the rear mount antennas
>  or the 1.2 Ghz antenna for side to side balance.
>
>
>
>
>
>
>
>
>
>
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
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----
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