Yes, MicroDEM is a PITA, but there is a wealth of information available
on how to use it and HFTA. The biggest PITA, actually, is that the USGS
contractor responsible for the seamless database and its web interface
keeps changing things, so that even a 2009 document is out of date on
the data download side. Nonetheless, the file provided with the Antenna
Book or available at
<http://www.arrl.org/files/file/Product%20Notes/Antenna%20Book/HFTA.pdf>
will, with a little intelligent modification to take care of the user
interface changes, produce exactly the terrain files you need and help
you use them in HFTA (which has *not* changed). I helped write the
instructions and, it appears, will need to rewrite them. Soon, I hope.
All this business about locating your antenna within feet or inches is
silly. The terrain data are markedly less precise than that, as Jim Lux
pointed out - more like some tens of meters. What MicroDEM does, if
used according to the instructions, is to draw radials from the antenna
location out some 3-4 miles, which are readable by HFTA as .pro
profiles. These radials are simply the electronic equivalent of drawing
pencil lines on a topographic map and entering the elevation at, say,
10-meter intervals
73, Pete N4ZR
The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at
reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000 and
arcluster.reversebeacon.net, port 7000
On 3/3/2012 9:48 PM, dotravel@aol.com wrote:
> Jim, if you did build a simplifiied way to enter the exact location of the
> antenna to import into HFTA you would be a hero to the masses because
> Microdem is a true PITA!
>
> Note that unless the site is on flat ground just entering the QTH location
> would not be enough. For the data to be of value, the location of the tower
> needs to be within feet if not inches prior to importing into HFTA.
>
> Regards, John NA6L
>
>
> -----Original Message-----
> From: Jim Lux<jimlux@earthlink.net>
> To: towertalk<towertalk@contesting.com>
> Sent: Sat, Mar 3, 2012 10:09 am
> Subject: Re: [TowerTalk] Where to get HFTA Software
>
>
> On 3/3/12 9:55 AM, Richard Thorne wrote:
>> Where can the software be obtained? Is it downloadable or do you have to
>> by the ARRL antenna book to get a copy?
>>
> Need to get a copy of the ARRL antenna book.
>
>> I'm in the middle of installing my tower and I'd like to run some numbers.
> I'd say it would be easy for someone to run it for you, but the real
> value comes from having the terrain data, which is a somewhat complex
> process and location specific.
>
> (although, I've thought about making some sort of web server that could
> take a call sign or lat/lon, generate the terrain files automatically.
> Seems like you could build some interface to Google Earth, for instance.
>
> That's way down on the list of software projects though...
> _______________________________________________
>
>
>
> _______________________________________________
> 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
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|