system. Diagnostic and maintenance program shall be accessible by way of
field located maintenance terminal.
2.3.3
Transmission Requirements
Transmission requirements are expressed in terms of analog measurements.
2.3.3.1
Input Impedance
Nominal input impedance of subscriber circuits and analog trunks of the
EPABX shall be 600 ohms. When connecting facility or equipment is other
than 600 ohms, Contractor shall provide required impedance matching devices
for proper operations.
2.3.3.2
Insertion Loss
Insertion loss: Between 0 dB and 2.0 dB for 2-wire to 4-wire, and 4-wire to
4-wire trunk connections. Between 0 dB and 2.0 dB for trunk-to-line
connections, and 0 dB to 6.0 dB for line-to-line terminations or
connections.
2.3.3.3
Stability
Components shall have long term loss variation of specified transmission
levels of not more than plus or minus 0.5 dB. Long term stability
requirement is defined as more than 10 years.
2.3.3.4
Frequency Response
Frequency response loss reading relative to 1004 Hz signal shall not exceed
the following:
Frequency
Trunk-to-Trunk
Trunk-to-Line
Line-to-Line
200 Hz
2.0 dB
2.0 dB
2.5 dB
300 Hz - 3 kHz
1.3 dB
1.3 dB
1.5 dB
3.4 kHz
0.5 dB
0.8 dB
0.8 dB
2.3.3.5
Return Loss
Return loss measured at 600 ohms shall not exceed the following:
Trunk-to-Line
Line-to-Line
Echo Return Loss (ERL)
20 dB
24 dB
Singing Return Loss (SRL)
14 dB
16 dB
2.3.3.6
For frequencies of 180, 540, 1000, and 2000 Hz, minimum balance shall be 60
dB; at 3400 Hz minimum shall be 50 dB.
2.3.3.7
Steady Noise
Idle channel noise with C-Message weighing at 600 ohms impedance measured
on terminated call shall be as follows:
Maximum
23 dBrncO
Average
18 dBrncO or less
SECTION 16720N
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