Thread: SPOT Assist
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Old 02-17-2010, 12:40 PM
Fr. Frank Fr. Frank is offline
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Join Date: Oct 2003
Location: Shalimar, Florida
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Default Re: SPOT Assist

Quote:
naval.com is not even close to Chapman's calculations.
6 ft antenna on either end produced a 6 mile range according to navel.com.

Am I doing something wrong???
This made me think. SO I went to "How Stuff Works" to find the following formula:
SquareRoot(height above surface / 0.5736) = distance to horizon.

That works out to about 1 mile for every 8 inches in height. So a 6' antenna (72 inches) has a line of sight of 9 miles.

I wonder if the current Chapman's still has the old guideline? My copy is from the late 1970's.
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