Nortel Networks Circuit Card User Manual

 NTAK79 2.0 Mb PRI card

This switch enables for the selective grounding of the Tx / Rx pairs of the 
carrier cable. Closing the switch (down position) applies Frame Ground 
(FGND) to the coaxial carrier cable shield, creating a 75 ohms unbalanced 
configuration. This applies only to the NTBK05CA cable. 

Note: The usual method is to ground the outer conductor of the receive 
coaxial signal.

The NTAK79 obtains its power from the backplane, drawing maximums of 
2 A on +5 V, 50 mA on +12 V and 50 mA on –12 V.

The NTAK79 meets all applicable Nortel Network’s operating specifications.

The NTAK79 card provides the following features and functions:

•

recovery of the 2.048 kbps data by the CEPT receiver, at signal levels 
which have been attenuated by up 10 dB

•

control of CEPT line density using HDB3 which provides 64 kbps clear 
channel

•

performance monitoring of the receive carrier by means of Bipolar 
Violations (BPV), Slips, CRC-4 (CRC), and Frame Bit Errors (FBER)

SW 4-1

Rx – FGND

Rx – OPEN

SW 4-2

Tx – FGND

Tx – OPEN