GTE Omni Si Database Technical Practices Issue 1 Manual

							SW 5210TL-130500-1001
NOTE: Exercise caution when extending four-wire trunks
over metallic facilities that may convert longitudinal voltages
to metallic voltage prior to reaching the 
PABX.36.6.15 The systems are capable of supplying digitally
generated tones (the tone levels indicated refer to levels
of tones at their point of departure from the 
PABX towards a
station), which are used in normal operation and with various
features. See Table 4.2 for a description of these tones.
36.6.16 The minimum facility leakage tolerance for trunks is 20
kilohms. On station lines, the minimum facility leakage tolerance
is dependent upon the ringer equivalency total connected to the
line in question as follows:
@ For one equivalent ringer, 15 kilohms
0 For two equivalent ringers, 17.5 kilohms
0 For three equivalent ringers, 20 kilohms
l For four equivalent ringers, 30 kilohms
0 For five equivalent ringers, 50 kilohms
36.6.17 To compensate for cable distances between the OTS
(Office Terminating Shelf) and the systems, optional pads are
available as listed in Table 36.4.
36.7 The system matrix is a zero TLP (Test Level Point) and the
digital milliwatt described in the 
D2- and D3-type compatibility
specification is used to align the systems in the factory. A similar
digital milliwatt is provided in the GTD-4600 system and is an
option in the 
OMNI SI. When the digital milliwatt is dial
accessed, the pad switching rules for a line are implemented.
The systems were designed to be compatible with 
D2- and
D3-type carrier systems and their alignment procedures.
The system must operate as the master unit when a 
D2- or
D3-type channel bank is associated with it via a direct digital
interface. The channel bank is aligned on a looped basis as it
would be if the distant terminal was another channel bank. The
+ 7 and -16 
TLPs are maintained, and drop levels per the VNLP
or FLP (as applicable) are set by adjusting the pads associated
with the four-wire terminating set. Once the channel bank is
adjusted properly, levels from the system’s digital tone source
or from an oscillator connected to an analog port on the system
can be verified.
As noted in paragraph 
36.6.1, the line impedance of the system
is 600 ohms. Two-wire trunks are 900 ohms and four-wire
trunks are 600 ohms. When making terminating measurements
on the system (MDF to MDF), hold coils and possibly battery feed
devices are required. If the test equipment used does not
provide these functions, a hold coil can be built locally. Figure
36.12 shows one such device that can provide holding and
battery feed functions with minimum transmission impairment.
ah37S-363 
						

							TL-130500-1001
Table 36.4 Optional Pads
IOPTION 1CABLEIFEETI
CIType 4162I321 to 550IIIIIGTS-8510351 to 650
(GT-16)
Transmission36.8
Test ProceduresAll systems are factory tested for transmission
performance. This paragraph provides a description of the
test procedures that are to be used if there is a need to make
transmission tests on the systems.
The path to be tested may be set up by using the available
test panels or by dialing up the connection in a normal fashion.
Refer to the appropriate section of FGBS Technical Practices for
system and test panel operation.
Battery Feed36.8.1 Depending on the test equipment used, a hold coil or
and Hold Coilbattery feed coil may be necessary to maintain the connection
Arrangementsacross the system. Other test equipment may require DC
blocking and a large capacitor will be required. The hold coil
and battery feed arrangements shown in Figure 36.12 are
recommended. For precise measurements, the loss, distortion,
etc. of these devices should be taken into account.
Insertion Loss Aad36.8.2 To measure insertion loss and frequency response,
Frequency Responseproceed as follows (test objectives are listed in paragraphs
36.6.2 and 36.6.3).
1. Establish a station-to-station, station-to-trunk or 
trunk-to-trunk path through the system. (Provide DC holding for
stations or incoming loop trunk circuits and provide a battery
feed arrangement for CO-type loop trunk circuits as shown in
Figure 36.12.)
2. Connect the transmission measuring set on the established
path as shown in Figure 36.13, and measure the end-to-end
loss in the frequency band from 204 to 3,404 Hz with the
oscillator set to a sending level of 0 
dBm.S-364
8187SW 5210 
						

							TL-130500-1001- output
100 MFBI-
T100 MF
O-800 
OHMS
4 Henries 100 OHMS- input 
----)
4 Henries 100 OHMS
DC Holding Coil
4 Henries
II
\
100 OHMSI
IIII
To
To
TEST
System SET
I100 MFDC Battery Feed
4 Henries
t
100 OHMS
hv-J--
100 MF
Figure 36.12
Hold Coil and Battery Feed Arrangements
SVR 52108187S-365 
						

							TL-130500-1001Level Tracking36.8.3 To measure the level tracking error, proceed as follows
Error and(test objectives are listed in paragraph 36.6.4).
C-Notch Distortion
1. Establish a station-to-station, station-to-trunk, or trunk-to-trunk path through the system. (Provide dc holding for
stations or incoming loop trunk circuits and provide a battery
feed arrangement for CO-type loop trunk circuits as shown in
Figure 36.12.)
2. Connect both the 600-ohm oscillator and frequency selectivemeter through a 0- through 
lOO-dB, 600-ohm decade
attenuator as shown in Figure 36.13.3. Adjust the oscillator for 1.004 KHz at 0 
dBm into 600 ohms and
the send attenuator for 
0-dB loss.
4. At the terminating end, adjust the frequency selective meter for
1.004-kHz and -50 dBm input sensitivity and the receive
attenuator for 
50-dB loss.
5. Vary the level into the PABX from 0 to -50 dBm by increasingthe send attenuator loss, while at the same time decreasing
the receive attenuator loss by equal steps.
NOTE: Two attenuators are needed to provide accurate level
adjustments in 
1-dB steps and to use the same meter scale for
all measurements to obtain an accuracy of + 
- 0.1 dB.To measure the C-notch distortion, proceed as follows (test
objectives are listed in paragraph 36.65).
1. Substitute a noise measuring set equipped with a C-notchfilter for the receive attenuator and frequency selective meter
(Figure 36.15).2. Adjust the oscillator for the C-notch frequency at levels from 0
to -50 
dBm.3. Measure and record the C-notch distortion. The 
signal-to-distortion ratio is the difference (in 
dB) of the measurement
without the C-notch filter and the measurement with the 
C-notch filter for each input level selected.
S-366
a/a7SVR 5210 
						

							TL-130500-1001PABXT
LineLine T
CircuitCircuit. .__....r
RR
--I
DC Holding Coil
DC Holding Coil
or
DC Battery Feed
(see Figure 36.12)
(see Figure 36.12)0 
dBM
TT1 
Eiji& 204t03;Hz 1 ~.o~g;~H- 1
SendNote: See paragraph 36.5Receive
-.a^*- __. __--__wgure 3ti.13
Insertion LOSS and Frequency Response Measurement
Intermodulation
Distortion, Envelope36.8.4 To measure intermodulation distortion, proceed as
follows (test objectives are listed in paragraph 36.6.6).
Delay Distortion,
and Noise1. Establish a station-to-station, station-to-trunk, or 
trunk-to-trunk path through the system. (Provide DC holding
for stations or incoming loop trunk circuits and provide a
battery feed arrangement for CO-type loop trunk circuits
as shown in Figure 36.12).
2. Connect the transmission measuring set on the established
path as shown in Figure 36.18.
3. Using the intermodulation distortion test unit, adjust the
send level for -10 
dBm and measure the second and third
order distortion products.
SVR 5210
8187S-367 
						

							TL-130500-1001
To measure the envelope delay distortion, proceed as follows
(test objectives are listed in paragraph 36.6.8).
1. Use the same test configuration established in paragraph
37.4.3, 1 and 2 along with an envelope delay test unit, which is
set at a modulation frequency of 
83-l/3 Hz.
2. Adjust the send level for -10 
dBm. Adjust the test unit for
1,840 Hz equal to 
0~s.3. Vary frequency and record delta from 1840 Hz reading.
To measure path message and impulse noise, proceed as
follows (test objectives are listed in paragraphs 36.6.9 and
36.6.10).1. Use the same test configuration established above along with a
noise measuring test set.
2. Set the sending portion of the transmission measuring set to
quiet termination.
3. Measure the C-message, 
~-KHZ flat, and impulse noise.
Crosstalk36.8.5 To measure the crosstalk attenuation, proceed as follows
Attenuation(test objectives are listed in paragraph 36.6.11).
1. Establish two paths through the system and provide the proper
holding or battery feed arrangement shown in Figure 36.42.
2. On one path, connect a 
900-ohm/600-ohm, 0-dBmoscillator at one end and terminate the far end in the proper
AC termination impedance as shown in Figure 36.15.
3. On the second path, connect a frequency selective meter at
one end of the path and terminate the far end in the proper AC
termination impedance shown in Figure 36.15.
4. Adjust the oscillator for 1,004 Hz at 0 
dBm and the frequency
selective meter for a frequency of 1004 Hz.
5. Measure the crosstalk attenuation.
Longitudinal36.8.6 To measure longitudinal balance attenuation, proceed
Balanceas follows (test objectives are listed in paragraph 36.6.3).
Attenuation1. Establish a path to the system’s quiet code termination or to a
terminated line or trunk as shown in Figure 36.16. The
required battery feed arrangement is applied only to trunks.
2. Using the longitudinal balance test set, measure the
longitudinal balance at 204, 1004, and 
30634 Hz.
SVR 5210 
						

							TL-130500-1001PABX
. . . . . . . . . . . . . . . . . .T i. . . . . . . . . . . . . . . .._Line 
! iLinei -I-
I . . . . . . . .
R ;; R
. . . . . . . . . . . . . . . .._:.................DC Holding Coil
(see Figure 36.12)DC Holding Coil
(see Figure 36.12)
Send600 OHM Attenuator
0 to 
100dBT
RReceive
600 OHM Attenuator
1 KHZ atOto 
1OOdBOor 
+3dBm600 OHMS
Transmission
Measuring Set
(see Note 1)
SendNotes:
1. See paragraph 36.5.
2.For tracking measurements, adjust the
transmission measuring set to 
+3 dBM at 1000 Hz
and adjust the send and receive attenuator so that
the combined loss equals -53 
dB (E.G., send = 0
receive = -53;
R- T
r‘\0
f600 OHMS or 900 OHMS
Transmission
Measuring Set
(see Note)
Receive
send 
= -10, receive = -43; send = -25,
receive = -25; ect.)
3.For C-notch measurements, remove the receiver
attenuator and frequency selective meter and
terminate with the noise measuring set equipped
with a C-notch filter
Figure 36.14Level Tracking and C-Notch Distortion Measurement
SW 52108187S-369 
						

							TL-130500-1001PABX
70 i i line il
i or‘-.j ori
: trunk : j trunk :__ __. _. . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . .-...........-...........
i line : : line :i line : : line :
-i or7: or:-.i or ::-.i 01 :
-i trunk : : trunk i-i trunk : : trunk i
ZIN = 6001900 ZIN = 600/900
OHMS OHMS
i (1rDC Holding Coil
DC Battery Feed
(Figure 37.12) DC Holding Coil
hh
2.16MF
-Frequency
Selective
MeterTransmission
Measuring Set
Receive
Send
Figure 36.15 Crosstalk Measurement
8167SVR 5210 
						

							TL-130500-I 001OMNI PABX
T
. . . . . . . . . _. . . . . . . . . . . . . . .._. i Line ~------------j Line _
Quite Termination
i orori or
i Trunk
R
r----‘,,. . . .._......_..._.Tmk.....\System 
duietCode Termination
OMNI PABX
Ground
ZM = Metallic Impedance = 750 OHMS
RGround
EL= Longitudinal Voltage = 10 VatType 207
TLongitudinal
Balance
Test Set
Figure 36.16Longitudinal Attenuation Measurement
Longitudinal36.8.7 To measure longitudinal 
susceptability, proceed as
Susceptabilityfollows (test objectives are listed in paragraph 36.6.14).
1. Establish a path to the system’s quiet code termination or to
terminated line or trunk as shown in Figure 36.17. The
required battery feed arrangement is applied only to trunks.
2. Apply a longitudinal signal so as to create a tip or ring to
ground voltage of 50 VAC maximum at 60 Hz or a longitudinal
current of 10 ma maximum at 60 Hz.
3. With a noise measuring set in the bridging mode, measure the
metallic C-message noise.
Echo and Singing36.8.8 To measure ERL and SRL, proceed as follows
Return Loss(test objectives are listed in paragraph 36.6.73).
1. Establish a station-to-station, station-to-t 
Ink, or trunk-‘o-trunk path through the system. 
Provic. 3 DC holding for
stations or incoming loop trunk circuits and provide a battery
feed arrangement for CO-type loop trunk circuits as shown in
Figure 37.12.
2. Connect a return loss measuring set and measure the echo
and singing return losses of the path as shown in Figure 36.18.
SVR 5210
8187s-371 
						

							TL-130500-1001
PABX-f- l!-----.: Y.------TPABX groundLJb nululrlyCoil or
DC Battery
Feed(see Figure
36.12)
600/
900
_ OHMS
2.16MF
AC
Q= 
10maMmaximum
RType 1200
1 .l RatioII-
1 OOOMF5 henries
200 OHMS
v- >-4ueu-
“I BG
ZM
750
( oh-(
tms
II
NOTES:
T1. Use LP strap for lines, BG straps for loop trunks, and NO
straps for E&M trunks.
2. The longitudinal 60 Hz generator will be adjusted to provide
50 VAC measured from tip or ring to ground or 
10ma of
logitudinal current.
LFigure 36.17Longitudinal Susceptibility MeasurementS-372
8187SW 5210