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6 Using SiS Mode Accessories
Now press the “Return” key. The screen should now show something similar to the below with the “+” icon showing and little or
no red shown in the distortion indicator.
52.1
SiS8440
25dB
The system is now ready to identify the cable at the location of interest.
Identifying a cable
Having confirmed the antenna is synchronized with the receiver, proceed to the location the cable is to be identified. Place the
antenna on each of the suspected cable in turn ensuring the correct orientation with the flats in line with the cable and the arrow
on the antenna pointing away from the transmitter.
Note the signal strength on each cable and also which polarity is indicated. The target cable will have the strongest signal and
will have a “+” polarity.
52.1
SiS8440
25dB
Enhancing the loopback method of cable identification with the aid of the SIS signal
As described before, a more reliable method of loop backing the signal on the cable is possible if the cable is out of service. This
method can be further enhanced with the aid of the SIS signal.
Method:
Set up the transmitter as below, with the far end connected together and with the transmitter connected across a twisted pair of
cable. Set the transmitter to a SIS frequency such as SIS 491Hz perform an SIS reset as described above.
At the location of interest, hold the antenna on each of the cables in turn. Run the antenna along the cable keeping the arrow on
the antenna pointing forwards. On the incorrect cable the signal level will be small and steady. On the correct target cable the
signal will rise and fall in sympathy with the twist in the cable. Also, if on the target cable, at each peak the polarity indicator will
also change in sympathy from “+” to “-”.
