Kudo's and many thanks to Steve for DEM files for my QTH. As others
mentioned, the Microdem/DEM web site is impossible - gratuitous GUI
violence by the site owner makes no edition of published instructions
useable.
OTOH, HFTA is pretty easy to use, once you have the DEM files.
If like most of hams, you are "working the world" with a single Yagi
then the value of HFTA IMHO is slight, since one solution fits all
paths/propagations/arrival stats. The usual "on average" answer is
the higher the antenna the better. One caveat, is for cliff edge and
mountain/ridge tops, where terrain significantly changes effective
height. If you are building a stack or fixed path antenna, then I think
there is great value in the analysis.
In any case, there are things to learn from the analysis.
Grant KZ1W
"There isn't any such thing as ground",
"Every picofarad has a little nanohenry all its own".
Vonada's Maxims
On 3/4/2012 4:42 AM, Steve W3AHL wrote:
> I supplied some HFTA plots to the N5ZC, the originator of this thread last
> night.
>
> If anyone else wants JUST the radial elevation profiles but doesn't want the
> hassle of learning Microdem and extracting the DEM elevation data, I can
> supply a zip file with the radial profiles at 5 degree intervals that HFTA
> expects, based upon 1/3 arc second (10m) resolution DEMs from USGS.
>
> I need your exact antenna location, preferably in decimal degrees to at
> least five decimal places. Using Google Maps or Google Earth is strongly
> encouraged.
>
> It takes about 20 minutes to generate the files -- mostly waiting for the
> DEM data to download from USGS. I did about 20 of these after a similar
> offer last December. It may take me a few days to send the files, depending
> on what else I'm doing.
>
> I would rather not do the full HFTA runs, unless you have some unusual
> circumstances that prevent you from being able to do it.
>
> Steve, W3AHL
>
> _______________________________________________
>
>
>
> _______________________________________________
> 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
|