Nortel BCM50 2.0 Installation Manual page 26

26 Chapter 4 Installing the analog terminal adapter
Figure 7 Insertion loss from the CO to the analog telephone
Longitudinal balance to ground
Overload level
Measure the total insertion loss between the CO and analog device by using standard dial-up test
lines with a transmission test set (for example, Hewlett-Packard 4935A Transmission Test Set).
To measure the insertion loss from the CO to the analog device
1 Establish a connection to the 1 mW, 1 kHz, CO service line with an analog telephone attached
to the ATA2.
2 Ensure that the analog port terminates correctly in 600 ohms:
• Replace the analog telephone with the test set.
• Use RECEIVE/600 OHM/HOLD mode on the test set.
3
Ensure that the test set connects in parallel to the service line before removing the analog
telephone, or the line drops.
4 Remove the single-line telephone.
5
Measure the 1-kHz tone at the far end of the analog port, which is where the analog loop ends
and where the analog device connects.
Note: The tone must be greater than - 10 dB (for example, - 9 dB is acceptable).
NN40020-309 NN40020-309
50 dB
60 to 4,000 Hz
With IEEE 455-1976 test
3 dB