that's a bit of a tall order if you are looking for something that gives 
some kind of textual representation of the lines and colors on the map the 
way most calculators do.
What kind of info would you want from this kind of calculator?  Where you 
would enter coordinants of each station and then ask the calculator to spit 
back a yes or no answer to weather this is a practical communications path?
The way all the calculators that I know of are set up is to show a foot 
print map, and different color representations of fixed station, mobile and 
handheld coverage out from a specific point.
I'm not sure anything exists that will give you some kind of text feedback 
if you plug in a fixed point or something and tell you what the max range 
is...there are allot of variables involved in that such as turraine, height 
of the transmitting antenna and height of the receiving antenna, power 
output, antenna gain and of course frequency.
Altitude, weather and humidity also play factors in VHF and UHF line of 
sight communications.  In perfect conditions, line of sight is nearly 
unlimited on both frequency bands.
IE satellite communications is essentially line of sight without any RF 
sucking obstructions and those are up to 13000KM away.


73
Colin, V A6BKX
-----Original Message----- 
From: Jim Gammon
Sent: Saturday, January 2, 2016 1:29 AM
To: [log in to unmask]
Subject: Re: Accessable VHF/UHF Line of Sight Calculator

Oh thanks Dave, I just couldn't imagine what kind of calculator
it might be.  I was thinking it was a hardware box like a
Calculator you do math with.  73, Jim

----- Original Message -----
From: Dave Marthouse <[log in to unmask]
To: [log in to unmask]
Date sent: Sat, 2 Jan 2016 02:48:58 -0500
Subject: Re: Accessable VHF/UHF Line of Sight Calculator

Jim,

This calculator will plot the line-of-sight signal distance
between two
stations on VHF or UHF.  In other words the typical non-enhanced
communications path over which the two stations can have good
reliable
communication.


Dave Marthouse N2
[log in to unmask]