Chapter 12 Installing Analog Terminal Adapters 155Installation and Maintenance GuideTesting insertion loss measurementThe maximum loss for ATA 2 to Central Office (CO) configuration, shown in Figure 64, must notexceed 10 dB.Figure 64 Insertion loss from the CO to the analog telephoneMeasure the total insertion loss between the CO and analog device by using standard dial up testlines with a transmission test set. For example, Hewlett-Packard 4935A Transmission Test Set.For CO to analog device measurementUse this procedure 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 attachedto the ATA 2.2 Ensure that the analog port terminates correctly in 600 ohms:a Replace the analog telephone with the test setb Use RECEIVE/600 OHM/HOLD mode on the test set3 Ensure that the test set connects in parallel to the service line before removing the analogtelephone 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 endsand where the analog device connects.)Longitudinal balance to ground 50 dB60 to 4,000 HzWith IEEE 455-1976 testOverload level 3 dBNote: The tone must be greater than - 10 dB (for example: - 9 dB is acceptable).Analog telephoneATA 2BCM1000Business Communications Manager to ATA 2ATA 2 to Business Communications Manager10 dB MaxCable lossCentral Officecable loss
