VHFcontesting
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[VHFcontesting] Thanks

To: <vhfcontesting@contesting.com>
Subject: [VHFcontesting] Thanks
From: kharker@cs.utexas.edu (Kenneth E. Harker)
Date: Fri Aug 15 11:30:55 2003
On Fri, Aug 15, 2003 at 10:19:51AM -0500, Todd and Sandy Sprinkmann wrote:

>   Is the 100' height a good one?  A person who has been contesting for a long 
> time suggested that anything over 70/80' was overkill.  That really surprised 
> me.  As a novice, I simply thought the higher the better, period.  (except 
> for eskip on 6) The immediate property I'm on is high and fairly flat.  As 
> you go away about a 1/4 mile in all directions, the land slopes down gently.  
> Beyond a 1/2 mile, the land is rolling hills, none of which is substantially 
> higher than the QTH we now live at.

You might want to check out SPLAT! (Surface Path Length And Terrain analysis 
application.)  Plug in your latitude and longitude and run some analyses at
different heights above ground to see if your line-of-sight coverage changes 
radically at different heights.  If you're over all the terrain obstacles out 
to several miles at 80', maybe going up to 100' isn't worth it.

http://www.qsl.net/kd2bd/splat.html

I would think that for single-hop Eskip on 6 meters, you would want at least 
one horizontally polarized antenna at 25-30'.

>   Here's what I want/envision as of now:  As for 6 meters, I don't see much 
> point in going crazy here with the sunspot cycle heading down.   A 6M5X at 
> about 30' will do eskip.  If I'm missing a lot of tropo capability by not 
> having another 6M5X (or heck, I could do a 6M7JHV as well) way up high, tell 
> me about it.

A high six meter yagi is great for working rovers.  Most rovers have poorer
antennas on six meters than they have on two meters, so the more that you
can do to compensate on your end, the better.  
 
-- 
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Kenneth E. Harker      "Vox Clamantis in Deserto"      kharker@cs.utexas.edu
University of Texas at Austin                   Amateur Radio Callsign: WM5R
Department of the Computer Sciences          Central Texas DX & Contest Club
Taylor Hall TAY 2.124                         Maintainer of Linux on Laptops
Austin, TX 78712-1188 USA            http://www.cs.utexas.edu/users/kharker/
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