At VHF, it matters not what your power level or frequency is. "Horizon" is
everything. A one watt transmitter and a one microvolt receiver (fairly
typical of this sort of equipment) has a theoretical range of something on
the order of a thousand straight-line miles. "Straight-line" is the
operative word here.

We regularly talk to astronauts on the shuttle with a watt or two at both
ends. That is because we can both "see" each other in both an optical and
radio sense. Once I lose eye contact with the receiver, I'm pretty much
committed to losing radio contact as well.

The equation for "horizon" is given as: horizon (in miles) equals the
square root of the antenna height in feet times two. Let's presume two
handheld antennas, both at 6 feet above the ground. That's twelve feet of
antenna height. Twice that is twenty-four. Square root of twenty-four is
roughly five, so you might expect five miles of transmit range. In Iowa.
In a plowed cornfield. Put airplanes, buildings, people, walls, and any
other absorber into the mix and range decreases dramatically. In your
example of a shopping mall, once they turn the corner and put a concrete
wall (with the required steel rebar in it) between thee and me, range goes
to poop in a scooper. That's a technical term. You'll catch on after a
while.

From thirty+ years of running a ham radio on the field in Oshkosh, I feel
fairly confident in predicting that you would be able to talk from "Airshow
central" near the main arch to any corner of the field. However, trying to
talk from FondDuLac North (down at the approach end of runway 36) to the
North 40 (down at the approach end of runway 09) would be a stretch.

Jim



Good point, it would ruin the freq. if the same garbage "lingo" eeked
into the aviation band. I'm curious though, I wonder what kind of
range and clarity a handheld 760 radio would have talking to another
one at an airshow? I know if you get too far apart in a shopping mall
with an FRS it gets hard to communicate. Are aviation handhelds far
superior in ground to ground range and clarity?