Appendix A. Appendix

Path Loss Calculations

Here’s a simple table of path loss calculations in free space for channels 1 and 11, with clear line of sight. See Chapter 6 for how to use these numbers to figure out how far your network can reach. Distances are in miles, losses are in dB.

Distance (miles)

2.412GHz (ch. 1)

2.462 GHz (ch. 11)

0.5

98.2

98.4

1

104.2

104.4

2

110.3

110.4

3

113.8

114.0

4

116.3

116.5

5

118.2

118.4

7

121.1

121.3

10

124.2

124.4

15

127.8

127.9

20

130.3

130.4

25

132.2

132.4

30

133.8

134.0

This path loss table was calculated with the following formula, rounded up to the nearest tenth:

L = 20 log(d) + 20 log(f ) + 36.6

For possibly the most authoritative source of radio information on the planet, check out the ARRL online at http://www.arrl.org, or see any of their excellent books (in particular, their UHF/Microwave Experimenter’s Manual and Antenna Book are definitive sources for learning about microwave communications).

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