On 1 Feb 2005 14:07:19 -0800, wrote:

What are my questions? I'm not overly keen on downloading a potentially
large
program, I then have to install, and take up more room, without knowing
what it is
I want to do with it, or even what it does... You are leaving me in the
dark too
much as to what this program does...Even they don't give a real
description.

Hi Mark,

What Mac is offering is a link to a propagation modeler that was
developed for the Voice of America engineers. This sucker is
complexity³ and by the trepidation offered in your response, you
probably would not like it very much. But that may be an over
reaching analysis in the domain of the psyche.

There are plenty of boxes to fill in, plenty of settings to establish,
and a host of targets to select. What they describe are your power,
your antenna, your path (which presumes you know your audience -
literally), their background noise level, the time of day, the height
of any ionospheric layer, the sunspot count. From this you get
probabilities of S+N/N at the receiver, fluctuation of signal level,
even issues of multipath and other interference.

What is the actual payoff is that it also paints a picture of the
characteristic of interest either in the form of a chart or on a map.
This makes for nice 24 hour MUF forecasts for your intended target (a
sub continental sized region on the globe) or actual signal levels, or
interference levels (and on and on and on....).

The software also allows you to tailor your antenna's characteristics.
I like to describe an impossible design with a 1° beam width and beam
height to then present me with a map of the world where it hits.
This, in a nutshell, pretty quickly dissolves arguments about the
value of any particular TOA. Why? Because even with this impossible
thin razor's edge of a lobe, when it leaps across the continent it
splashes down into a fairly large region. A standard monopole
radiation characteristic will illuminate continental wide swaths of
the globe with alternating layers of good reception and poor reception
like ripples across a spherical metallic sea. The link:
http://www.qsl.net/kb7qhc/propagation/index.htm
offers just such a treatment with 24 forecasts of a standard monopole
(one each hour in a day) in an animated GIF loop. It is interesting
to see the sun revolving around Seattle (Galileo had it all wrong as
science will prove). Please note the server at qsl.net is quite slow
to the point of downloading all 24 images to run the animation.

73's
Richard Clark, KB7QHC