Setting the frequency span – Bird Technologies SA-1700-P User Manual
Page 44
Bird Site Analyzer
34
Setting the Frequency Span
The frequency span and relative propagation velocity
determine the maximum distance at which distance-
to-fault measurements can be taken. For best results,
use the table below to select the frequency span which
matches the length and propagation velocity of the
cable under test.
☞
NOTE: Changing the frequency settings will
automatically turn calibration off. Always set
the frequency before calibrating the unit.
Table 1: Fault Location Distance and Resolution
Velocity
Percentage
66 %
88 %
Freq Span
(MHz)
Distance
Resolution
Distance
Resolution
m
ft
cm
in
m
ft
cm
in
25
938.5
999.9
396.0
50.6
999.9
999.9
421.9
50.6
50
469.3
999.9
198.0
50.6
625.7
999.9
264.0
50.6
75
312.8
999.9
132.0
50.6
417.1
999.9
176.0
50.6
100
234.6
769.8
99.0
39.0
312.8
999.9
132.0
50.6
200
117.3
384.9
49.5
19.5
156.4
513.2
66.0
26.0
300
78.2
256.6
33.0
13.0
104.3
342.1
44.0
17.3
400
58.7
192.5
24.8
9.7
78.2
256.6
33.0
13.0
500
46.9
154.0
19.8
7.8
62.6
205.3
26.4
10.4
600
39.1
128.3
16.5
6.5
52.1
171.1
22.0
8.7
700
33.5
110.0
14.1
5.6
44.7
146.6
18.9
7.4
800
29.3
96.2
12.4
4.9
39.1
128.3
16.5
6.5
900
26.1
85.5
11.0
4.3
34.8
114.0
14.7
5.8
1000
23.5
77.0
9.9
3.9
31.3
102.6
13.2
5.2
1200
19.6
64.2
8.3
3.2
26.1
85.5
11.0
4.3
1400
16.8
55.0
7.1
2.8
22.3
73.3
9.4
3.7
1600
14.7
48.1
6.2
2.4
19.6
64.2
8.3
3.2
1675
14.0
46.0
5.9
2.3
18.7
61.3
7.9
3.1