EXFO CableSHARK P3 VF/DSL Cable Qualifier - Manual (Page 194)

VF / DSL Cable Qualifier
182
TERM IMP: The CableSHARK's impedance needs to match the characteristic impedance of
the cable. This causes the CableSHARK at either end of a test (including Single
End) not to reflect back any test signals or unnecessarily attenuate the test signal.
The options are 100 ohms and 135 ohms (no AUTO option for Return Loss test,
older units will show 120 ohms and 150 ohms)
10.1 Running a Return Loss Test
Use caution when connecting the test set, as telephone cables may have dangerous A.C. or D.C.
voltages on them.
Press the RUN / STOP button on the front of the CableSHARK to initiate the Return Loss test. Figure 10.1A
shows an example of the results obtained from a Return Loss Test.
Test completed.
MAIN
MENU
E F CHG
SAVE/
UPLOAD
dB
17 565 1113 2208 kHz 1660
Level
Cursor position = 29.3 dB
= 1000.500 kHz
0.0
10.0
20.0
30.0
40.0
50.0
60.0
SHOW
REF
Impedance = 100 ohms
ZOOM IN
HORIZ ZOOM IN
VERT TEST
SETUP
Press or to move cursor
dB
0.0
10.0
20.0
30.0
40.0
50.0
60.0
F IGURE 10.1A – C OMPLETED RETURN L OSS TEST