> > 3) The instructions given for creating the terrain profile files do not
> > work. The version of MicroDEM on the CDROM doesn't save the profiles
> > created in the viewshed analysis. It doesn't allow you to click the
"save
> > radials" option, which is grayed out. The HFTA pdf file tells you that
you
> > can enter the lat/lon for the viewpoint once you have clicked on the DEM
> > data, but in reality, it's where the cursor is when you (double) click
that
> > determines the viewpoint.
>
>
> Yes - using MicroDEM to get the terrain data is a bit hard.
> But the method I used before this program is MUCH more
> time cosuming and trouble - drawing lines on USGS maps
> and reading off the elevations makes you really appricate
> how much faster and easier it is to use MicorDEM.
Been there done that, wrote and sold software to do it...
My basic point is that this is something that the review process should have
addressed. I don't know what the production budget is for the ARRL antenna
book (not huge, I imagine), but I suspect that if a general request for a
suitable program had been disseminated, one would have turned up, or been
written. Certainly, I will write such a program.
>
>
> > 4) It would have been much better if they had simply provided a single
> > program that you enter the lat/lon of the station, how many radials, how
> > far, what post spacing, etc. in a dialog, and it would spit out the
required
> > text files. Sure, it's cool to use a sophisticated mapping program, but
> > there's a lot more that can go wrong.
>
> That would be nice - do you know of such a program? I think N6BV or
> someone else would have to write one. Instead Dean provides instructions
> to use MicroDEM to get the data - and I think he also still gives
> you the option of getting the elevation data off of a map.
>
>
> > 5) There is no documentation about how HFTA works, in either the program
> > documentation, or in the Antenna Book. There's a general description in
the
> > book of the diffraction analysis, but no theory, and what's important,
no
> > place to go look for a better description. The textbook cited on GTD is
all
> > well and good, but I wasn't looking forward to rederiving how HFTA might
> > work from first principles.
>
> Sounds like it would be a good idea - I think alot of this was
> covered several years ago in a QEX article that N6BV wrote.
So why not put the QEX article on the CD-ROM? It's not like ARRL has to
deal with copyright issues, since they're the copyright owner for QEX as
well.
Jim, W6RMK
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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