Im planning on a tower mounted rotatable dish for the 3 bands above 2304 but
it will be probably 40" tops. For 1296 and 2304 I use 4 55 el DEM loopers
and they hear way better than some of the stations Im calling. A 10' dish on
1296 with -20-25 dB side lobes would be like aiming a rifle for terrestial
work.
Carl
KM1H
----- Original Message -----
From: "Jim Hoge" <knowkode@sbcglobal.net>
To: <towertalk@contesting.com>
Sent: Saturday, May 19, 2007 8:27 PM
Subject: Re: [TowerTalk] Dish On A Tower
> Jim,
>
> That's assuming the dish will be aimed at the horizon. What is the
> intended application, terrestrial or lunar? If for EME, I don't understand
> the height above ground. The advantage of EME besides being lower is that
> the dish can be parked aiming straight up, greatly reducing drag. Still
> needs a robust mount though. If for terrestrial, possibly giving up a few
> dB for a yagi array is an option. My 4x array of 35? element M2 yagis
> produces ~24 dB while a dish should be ~30dB. Considerably smaller
> installation too.
>
> my two cents,
> Jim W5QM
>
> Jim Lux <jimlux@earthlink.net> wrote:
> At 03:11 AM 5/19/2007, JMLTINC@aol.com wrote:
>>
>>Hello to all,
>>
>>I am considering using a 10' dish for 1296. I would like to see it up 70'.
>
> To a first order, you're looking at a drag area of 3.14*25 square
> feet (what's that, about 80 square feet?)
>
> In a 80 mi/hr wind (16 lb/sf, roughly) that's going to be 1280 pounds
> of wind drag!
>
> better be a burly tower.
>
>
>
>
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