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Ant. Hght vs. Dist Chart
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Ant. Hght vs. Dist Chart
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This is a handy chart to help to aproximate your radio range for line-of-sight coverage.  This is based on use for the 2 Meter band.  As to go up to higher bands, coverage will slightly decrease.  It still makes for a rough starting point.

How To Use This Chart
     Take a height closest matching your actual height or desired height of Station (1), and do the same for station (2), then add the two distances.  Example two people using Handy Talk Radios.  Both would be about 5 feet off the ground.  Each would have an expected range of about 3.4 Miles.  The Total Range would then be 6.8 Miles above average flat Earth without hills, buildings, and or trees.  The more things in your transmission path, will lesson your signal and range. (Asumming you are using at least 5 Watts or more.)

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A COMMENT ABOUT MATH...
 
     I know most of may have grown up thinking that most math we learn in school has no real value that applies to every day life. However I found that is not the case when I was setting up this page.  I found with the help of an article from QST article, that I would need to learn how to use the "Pythagarean Therom."  Simply  put, C = sruare root of ( A2 + B2).  Doesn't sound too useful until you realize, you take the radius from the center of the earth to the surface, (convert to feet) and the same again, but you add the height above earth that the antenna will be located. This will from A2 + B2. Add these together and then get the square root, and you will have your answer, but will have more meaning if you now convert feet to miles.
     This was just one of many examples.  It is used a lot with a cashier (finding the correct change after entering the wrong amount in a register.  Or how fuel effient your car is, and deciding if you should keep it because of gas prices.  Or building a tuned dipole for your favorite frequency.  How many squarefeet your room has that you want to tile or carpet.  You know what they say, "knowledge is Power."  I argue that math shows you how to use that power.  Only with math have we figured out how to go into outerspace, or to build a plane, or even a nuclear bomb.  I periodic table of elements have specific numbers attached  to them for compairative, diagnostic, and mathmatical reasons.  Computers are almost all math.  Binary code is nothing more than math based on "1's" and "0's."  This is used to control everything from pictures, sounds, operating systems, and even the letters on your screen.  The abillity to conquer math is one of the big things that separates us from the animals.

Antenna Height Above The Earth in FEET
Expected Range Half in MILES.
5 FEET
3.4 MILES

10 FEET

6.5 MILES

20 FEET

10.1 MILES

30 FEET

12.8 MILES

40 FEET

15.0 MILES

50 FEET

16.9 MILES

75 FEET

20.9 MILES

100 FEET

24.2 MILES

125 FEET

27.2 MILES

150 FEET

29.8 MILES

175 FEET

32.3 MILES

200 FEET

34.5 MILES

250 FEET

38.7 MILES

300 FEET

42.4 MILES

350 FEET

45.9 MILES

400 FEET

49.0 MILES

500 FEET

54.9 MILES

600 FEET

60.1 MILES

700 FEET

65.0 MILES

800 FEET

69.5 MILES

900 FEET

73.7 MILES

1000 FEET

77.7 MILES

1500 FEET

95.2 MILES

2000 FEET

110.0 MILES

5000 FEET

174.0 MILES

10,000 FEET

246.2 MILES

20,000 FEET

348.1 MILES

30,000 FEET

426.4 MILES

40.000 FEET

492.4 MILES

50,000 FEET

550.5 MILES

60,000 FEET

603.1 MILES

70,000 FEET

651.5 MILES

80,000 FEET

696.5 MILES

100,000 FEET

778.7 MILES

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