Nortel Networks BCM200, 400 4.0 manual Insertion loss from the CO to the analog telephone

Chapter 11 Installing the analog terminal adapter 171

Figure 85 Insertion loss from the CO to the analog telephone

Central Office cable loss

BCM main unit ATA 2 Analog telephone

Cable loss

BCM to ATA 2

ATA 2 to BCM

10 dB Max

Longitudinal balance to ground	50 dB
	60 to 4,000 Hz
	With IEEE 455-1976 test
Overload level	3 dB

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

1Establish a connection to the 1 mW, 1 kHz, CO service line with an analog telephone attached to the ATA2.

2Ensure 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.

3Ensure that the test set connects in parallel to the service line before removing the analog telephone or the line drops.

4Remove the single-line telephone.

5Measure 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).

To measure the insertion loss from the analog device to the CO

1Establish a connection to a silent termination on the CO service line with an analog telephone attached to the ATA2.

2Make sure the analog port terminates correctly in 600 ohms:

BCM200/400 4.0 Installation and Maintenance Guide