Appendix B. Path Loss Calculations
Here is a simple table of path loss
calculations in free space for channel 1 with clear line of sight
(the difference in path loss from channel 1 to channel 11 is
negligible). See Chapter 6 shows how to use these
numbers to figure out how far your network can reach. Distances are
in miles; losses are in dB.
|
0.5
|
98
|
|
1
|
104
|
|
2
|
110
|
|
3
|
114
|
|
4
|
116
|
|
5
|
118
|
|
7
|
121
|
|
10
|
124
|
|
15
|
128
|
|
20
|
130
|
|
25
|
132
|
|
30
|
134
|
The path loss table above was calculated with the following formula,
rounded up to the nearest whole number:
- L = 20 log(d) + 20 log(f) + 36.6
Check out ARRL online (http://www.arrl.org) for what might be the
most authoritative source of radio information on the planet. Their
excellent books (in particular, UHF/Microwave
Experimenter's Manual and The
ARRL Antenna Book) are the definitive sources for learning
about microwave communications.
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