TECHNOLOGY BRIEF

Independent T-1 Test Verification

A multiplexer (MUX) OEM evaluated Quabbin P/N 9720 for their equipment. Their lab test data confirmed that P/N 9720 met all T-1 requirements, fit modular connectors and passed FCC/Bell Core EMI radiation and emission standards.

Test equipment:

  • A Dual CSU and a TBerd 211 were used for data transferring and to measure signal power level.
  • Tektronix 2402A & 2440 oscilloscope was used for testing the T1 signal pulse shape.

Tests performed:

  1. Error-free data transfer:
    For all cable lengths, the cable under test (CUT) is connected between one DS1 port of the Dual CSU and the TBerd. All T1 test patterns available in the TBerd are exercised. TBerd is monitored without any logic bit errors, CRC errors or BPV errors.
  2. Signal Parameters:
    Cable
    Length
    Power
    Level
    Amplitude Pulse
    Width
    Rise
    Time
    Fall
    Time
    2'
    20'
    1000'
    0 dBdsx
    -0.2 dBdsx
    -4.8 dBdsx
    2.79V peak
    2.75V peak
    1.50V peak
    348 nS
    346 nS
    346 nS
    43.2 nS
    44.3 nS
    192.3 nS
    32.1 nS
    32.1 nS
    167.3 nS

    Pulse Shape–20 foot Assembly

  3. EMI testing:
    A total of 13 Quabbin cables, 20 feet in length, were used for FCC and BellCore EMI testing on the T-1 and Dual CSU cards. The Quabbin cables exhibited no problems as far as EMI is concerned as long as the shield was correctly terminated.
  4. Cable resistance:
    For the 1000 foot cable, each conductor was measured around 16 ohms. ( = 0.016 ohm/ft) The resistance of the shield was measured around 5 ohms.

Conclusion: Based on the results of all the tests performed on Quabbin P/N 9720, we should have no problems using it for T1 data transferring. Since each pair of conductors is shielded separately, this will eliminate the possibility of crosstalk between TX and RX leads. Furthermore, it fits better in RJ48 and RJ45 connectors.