Nortel Circuit Card, Installation Manual, Page: 619 / 908

NT8D14 Universal Trunk card Page 619 of 906
Circuit Card Description and Installation
• DID trunks exceeding a loop resistance of 600 ohms
• RAN trunks operating in pulse start or level start modes
Figure 140 on page 620 shows jumper locations on the universal trunk card
(vintage BA).
Service change entries
The trunk type, terminating impedance, and balance network are selected by
making service change entries in the Trunk Administration program LD 14.
See Table 193 on page 621 for the proper values for the trunk type and loop
length. Refer to Software Input/Output: Administration (553-3001-311) for
LD 14 service change instructions.
Before the appropriate balance network can be selected, the loop length
between the near-end and the far-end (a Central Office, for example) must be
known. To assist in determining loop length, some typical resistance and loss
values for the most common cable lengths are given in Table 194 on
page 622
for comparison with values obtained from actual measurements.