Setting the frequency span – Bird Technologies SA-4000 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 either the propagation velocity
or dielectric constant 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: Frequency Span vs. V
p
Velocity
Percentage
Dielectric
Constant
60%
2.778
80%
1.562
100%
1
Frequency
Span (MHz)
Distance
ft (m)
Resolution
in (cm)
Distance
ft (m)
Resolution
in (cm)
Distance
ft (m)
Resolution
in (cm)
1900
37 (11)
1.9 (4.7)
49 (15)
2.5 (6.3)
62 (19)
3.1 (7.9)
1800
39 (12)
2.0 (5.0)
52 (16)
2.6 (6.7)
65 (20)
3.3 (8.3)
1700
41 (13)
2.1 (5.3)
55 (17)
2.8 (7.1)
69 (21)
3.5 (8.8)
1600
44 (13)
2.2 (5.6)
59 (18)
3.0 (7.5)
73 (22)
3.7 (9.4)
1500
47 (14)
2.4 (6.0)
62 (19)
3.2 (8.0)
78 (24)
3.9 (10.0)
1400
50 (15)
2.5 (6.4)
67 (20)
3.4 (8.6)
84 (26)
4.2 (10.7)
1300
54 (16)
2.7 (6.9)
72 (22)
3.6 (9.2)
90 (27)
4.5 (11.5)
1200
59 (18)
3.0 (7.5)
78 (24)
3.9 (10.0)
98 (30)
4.9 (12.5)
1100
64 (19)
3.2 (8.2)
85 (26)
4.3 (10.9)
106 (32)
5.4 (13.6)
1000
70 (21)
3.5 (9.0)
94 (29)
4.7 (12.0)
117 (36)
5.9 (15.0)
900
78 (24)
3.9 (10.0)
104 (32)
5.3 (13.3)
130 (40)
6.6 (16.7)
800
88 (27)
4.4 (11.2)
117 (36)
5.9 (15.0)
146 (45)
7.4 (18.8)
700
100 (31)
5.1 (12.9)
134 (41)
6.8 (17.1)
167 (51)
8.4 (21.4)
600
117 (36)
5.9 (15.0)
156 (48)
7.9 (20.0)
195 (60)
9.8 (25.0)
500
141 (43)
7.1 (18.0)
187 (57)
9.5 (24.0)
234 (71)
11.8 (30.0)
400
176 (54)
8.9 (22.5)
234 (71)
11.8 (30.0)
293 (89)
14.8 (37.5)
300
234 (71)
11.8 (30.0)
312 (95)
15.8 (40.0) 390 (119) 19.7 (50.0)
200
351 (107) 17.7 (45.0) 469 (143) 23.6 (60.0) 586 (179) 29.5 (75.0)