In article , "The Shadow" wrote:
The range of these units is dependant on:
1. Altitude of the transmitting and receiving units
2. Power
3. Frequency
4. Obstructions
5. Antenna Gain
6. Receiver Sensitivity

For a Handy chart to estimate range-- See URL:
http://www.artscipub.com/simpleton/simp.range.html

I have transmitted over a 50 Mile range with 5 Watts - but was on top of a
mountain (like most repeaters)

At ground level for both units with standard antennas, range is a few miles.
Anything else is hype.
Pretty much the distance to the horizon -- see URL:
http://www.boatsafe.com/tools/horizon.htm

The Shadow
Lamont

Power buys little extra range for unobstructed distance. Obstacles
is where power is inportant. I am not sure that 2 watts is maximum.
I was doing a test of a .5 watt Icom and a ~ 16 mi Midland. It
seemed to me the field strength was more than double. I
would think quadrupling power would double field voltage and I was
getting more than double field strength. .5 watt FRS have been reports of ~100 miles
between mountain tops. Nuts & Volts reported something like a 160 mi
skip of some sort in their FRS articles a long time ago. Ground level on boats
is normally about 3 mi., but air effects can increase that a whole bunch.
I don't know what mode of transmission I used to get when i
used my old 300 mw analog cell phone up around Lake Erie.
I used to go through a Canadian site in London from Astabula Ohio, about 70 mi.
That used to come in better than the US sites along the water at times.

greg