TM-11-5895-1012-10
T M
1 1 - 5 8 9 5 - 1 0 1 2 - 1 0
WARNING
WARNING
DANGEROUS VOLTAGES are present during the preparation of the test circuits
6-20. Turn all power switches off before constructing them test circuits. Failure
could result in serious injury or death.
TM 11-5895-1012-10
TECHNICAL MANUAL
DEPARTMENT OF THE ARMY
WASHINGTON, DC, 4 January 1978
No. 11-5895-1012-10
OPERATOR'S MANUAL
TECHNICAL CONTROL FACILITY
(GENERAL)
REPORTING OF ERRORS
You can improve this manual by recommending improvements using DA Form 2028-2 (Test) located
in the back of the manual. Simply tear out the self-addressed form, fill it out as shown on the sample,
fold it where shown,, and drop it in the mail.
If there are no blank DA Forms 20-28-2 (Test) forms in the back of the manual, use the standard DA
For 20-28 (Recommended Changes to Publications and Blank Forms) and forward to Commander,
US Army Electronics Command, ATTN: DRSEL-MA-Q, Fort Monmouth, New Jersey 07703.
In either case a reply will be furnished direct to you.
TABLE OF CONTENTS
CHAPTER
CHAPTER
Section
CHAPTER
Section
CHAPTER
Section
Section
CHAPTER
CHAPTER
APPENDIX
APPENDIX
INDEX
Number
2-1,
2-2,
2-3,
2-4,
2-6,
2-6,
2-7,
2-81,
2-82,
2-83,
2-84,
2-85,
2-9,
2-10,
2-11,
1.
2.
I.
II.
III.
IV.
3.
I.
II.
III.
4.
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
5.
6.
A.
B.
.... ..
INTRODUCTION
DESCRIPTION OF TECHNICAL CONTROL FACILITY
General... . . . . . . . . . . . . . . . . . . . . . .
System Service Interfaces, and Types of Signals . . . . .
The Technical Control Facility . . . . . . . . . . . .
.
Representative TCF Equipment . . . . . . . . .
EXAMPLES OF OPERATIONAL TCF'S
Pirmasens . . . . . . . . . . . . . . . . . . . . .
Berlin............ ......... . . .
....... .
Pentagon . . . . . . . . . . . .
TCF OPERATIONS
. .
Operation Practices and Methods. . . . .
...
circuit Rerouting . . . . . .
Patching Operations. . . . . . . . . . . . . . .
.
Failures and Fault Isolation . . . . . . . . . .
Performance Standards and Test Measurements .
Circuit Performance and Quality Control Testing .
Implementation of Communications Services Requirements
Acceptability of New Equipment . . . .
STATION MAINTENANCE .
TEST PROCEDURES... . . . . . . . . . . .
REFERENCES.. .
: .
ABBREVIATIONS.. . . .. ... . . . . .. . .
Paragraph Page
1-1. , 1-1
2-1.
2-7.
2-15.
2-30.
,
,
,
,
2-1
2-4
2-11
2-34
3-1. , 3-1
3-4. , 3-3
3-7. , 3-6
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.
.
4-1.
4-13.
4-17.
4-22.
4-39.
4-46.
4-56.
4-60.
5-1.
6-1.
LIST OF ILLUSTRATIONS
Title
. ..
Example of a world-wide common user network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. .
...
. . .
..
Interconnection of communications facilities, simplified diagram . . . . . . . . . .
Subsystem interface with the DCS. . . . . . . . . . . . . . . . . .
AUTODIN Interface with the DCS .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Control Facility, interface diagram .
...................
Technical Control Facility, configuration block diagram . . : . . . .. . . . . . . . .
Technical Control Facility, typical floor plan . . . . . . . .
.. ..... : .. ... :
Typical voice frequency circuits (Sheet 1 of 5)....... . . . . ... .. .
Typical voice frequency circuits (Sheet 2 of 5)
..... .. . . . ... . .. . ...
Typical voice frequency circuits (sheet 3 of 5) . ...... . . ..... .. -Typical voice frequency circuits (sheet 4 of 5) . . . . . . . . .
: .
Typical voice frequency circuits (sheet 5 of 5) . . . . . . . . . . . . . . . . ... .. .......... .........
Standard dc/data access circuits.. . . . . . . . . . . . . . . . .
..
Double bus arrangement and automatic transfer panel, wiring diagram.:. . . . . .... . . .
Uninterruptible power supply in standby condition. . . . . . . . . . . . . . . ......... . . . . . . . . . . . . . . . . . . . , . . . .
,
,
,
,
,
,
,
,
,
,
4-1
4-4
4-6
4-12
4-31
4-39
4-46
4-49
5-1
6-1
A-1
B-1
Index 1
Page
2-5
2-7
2-9
2-10
2-13
2-14
2-16
2-17
2-18
2-20
2-21
2-23
2-25
2-29
2-31
i
TM 11-5895-1012-10
Number
2-12
2-13
2-14
2-16
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-25
2-26
2-27
3-1
3-2
3-3
3-4
4-1
4-2
4-3
4-4
4-6
4-6
4-71
4-72
4-81
4-82
4-83
4-91
4-92
4-10
4-11
4-12
4-13
4-141
4-142
4-143
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
6-14
6-15
6-16
6-17
6-18
6-19
6-20
FO-1
FO-2
FO-3
FO-4
FO-5
FO-6
ii
Title
Page
2-31
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Uninterruptible power supply in on-line condition
2-32
ADMSC uninterruptible power system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-34
Solid state uninterruptible power system, simplified block d&gram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-39
Voice frequency primary or equal level and signaling patch panels front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-40
E&M patch panel, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-41
Two-wire voice frequency primary patch panel, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-43
Dc patch panel, low level receive, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-44
Dc patch panel, low level transmit, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-46
DC patch panel (transmit or receive) with cut keys and lamps, front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-47
Typical miscellaneous patch panel, front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-48
Miscellaneous/interbay patch panel, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-49
Voice frequency interbay patch panel, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-50
Typical series and parallel interbay trunking systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-51
DC interbay patch panel with 48 lamps, front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-52
DC interbay patch panel with 48 lamps, interconnection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-53
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Miscellaneous patch panel with 10 lamps, interconnection diagram
3-8
Red digital patch bay (typical), front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-8
Red digital test bay (typical), front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-9
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Red vf test bay (typical). front view
3-10
Quality assurance test center (Pentagon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-8
Transfer of circuit to spare multiplex channel at the equal level patch panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-9
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Transfer of circuit to spare cable circuit at the primary patch panel
4-10
Substitution of line conditioning equipment using the equal level and primary patch panels. . . . . . . . . . . . . . . . . . . . .
4-11
Transfer of a Dc circuit to a spare VFCT channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-13
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Transfer of a Dc circuit to a spare digital line interface unit (DLIU).
4-14
...........................................................
Transfer of a Dc circuit to a spare cable pair
4-21
Noise burst on multiplexed through circuit, fault isolation flow chart (sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-22
Noise burst on multiplexed through circuit, fault isolation flow chart (sheet 2 of 2).. . . . . . . . . . . . . . . . . . . . . . . . . . .
4-23
Noise burst on a local subscriber circuit, fault isolation flow chart (sheet 1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-24
Noise burst on local subscriber circuit, fault isolation flow chart (sheet 2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-25
...............................
Noise burst on local subscriber circuit, fault isolation flow chart (sheet 3 of 3)
4-26
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Vf subscriber circuit loop-back method, fault isolation flow chart (sheet 1 of 2)
4-27
Vf subscriber circuit loop-back method, fault isolation flow chart (sheet 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-38
Relative envelop delay vs frequency limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-44
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Sample distortion trend analysis chart
4-44
Sample noise level trend analysis chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-45
Sample number of outages trend analysis chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-50
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Sample voice frequency circuit configuration connection diagram (sheet 1 of 3)
4-50
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Sample voice frequency circuit configuration connection diagram (sheet 2 of 3)
4-51
Sample voice frequency circuit configuration connection diagram (sheet 3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-3
Idle channel (residual) noise test.
6-4
Frequency response test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-5
Envelope delay distortion test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Audio frequency test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-9
Longitudinal balance input test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-10
Longitudinal balance output test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Single tone interface test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Conversion dBm to dBrnc0. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-13
Impulse noise test. . . . . . . . . . . . . . . . . . . :
6-14
Terminal impedance test for transmit circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-15
Terminal impedance test for receive circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-18
Harmonic distortion test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-17
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Composite signal transmission level test
6-18
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Phase jitter testing using an oscilloscope
6-19
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Phase jitter testing using a phase jitter meter
6-21
Station to station signaling test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-22
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In-stations signaling test
6-22
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Net loss variation test
6-23
Station to station total peak and average bias telegraph distortion test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-24
In-station total peak and average bias telegraph distortion test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Simplified power distribution system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Vf primary or equal level patch panel, interconnection diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Primary Dc patch panel, interconnection diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Dc patch panel (receive) with cut keys and lamps, interconnection diagram. . . . . . . . . . . . . . . . . . Located in back of manual
Dc path panel (transmit) with cut keys and lamps, interconnection diagram . . . . . . . . . . . . . . . . . . . Located in back of manual
TCF Pirmasens, signal diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
TM 11-5895-1012-10
Number
FO-7
FO-8
FO-9
FO-10
FO-11
FO-12
FO-13
FO-14
FO-15
FO-16
Page
Title
Located
in
back
of
manual
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TCF Pirmasens, floor plan
TCF Berlin, signal diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
TCF Berlin, floor plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
TCF Pentagon, signal diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
TCF Pentagon, floor plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
TCF Pentagon, QA test center floor plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Typical black digital circuit IDF connection diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Universal digital patch panel, interconnection diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Universal digital patch panel black send circuit strapping diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
Universal digital patch panel black receive circuit strapping diagram . . . . . . . . . . . . . . . . . . . . . . . . . . Located in back of manual
iii
TM 11-5895-1012-10
CHAPTER 1
INTRODUCTION
1-1. Scope
a. This technical manual describes a Technical Control Facility (TCF) in general terms. It addresses the
purpose and function of the TCF; provides description
as to how a TCF will fit into the overall Defense Communications System (DCS) and the various types of
signal which could appear at a TCF’s patch panels.
b. Included is a description of a typical Technical
Control Facility; the off-site systems and equipment
which could interface with it as well as that equipment
most usually located within the TCF, and a typical test
equipment load which is used for testing and troubleshooting of communications circuits controlled by the
c. This technical manual also describes TCF operations which include operational practices and methods, circuit r&oration procedures, implementation of
communications services requirements, typical circuit
troubleshooting procedures and testing of circuit performance and quality.
1-2. Indexes of Publications
a. DA Pam 310-4. Refer to the latest issue of DA
Pam 310-4 to determine whether there are new editions, changes or additional publications pertaining to
theequipment.
b. DA Pam 310-7. Refer to DA Pam 310-7 to determine whether there are modification work orders
(MWO's) pertaining to the equipment.
1-3. Forms and Records
a Reports of Maintenance and Unsatisfactory
Equipment. Maintenance forms, records, and reports
38-750.
P4610.19C, and DLAR 4500.15.
1-4. Administrative Storage
ment, refer to TM 740-90-1.
1-5. Destruction of Army Material
1-6. Reporting Equipment Improvement
Recommendations (EIR)
1-7. Abbreviations
1-1
TM 11-5895-1012-10
CHAPTER 2
DESCRIPTION OF TECHNICAL CONTROL FACILITY
Section I. GENERAL
2-1. Purpose
f. Exercise technical direction, coordination and supervision over activation, deactivation and rearrangement of transmission facilities in accordance with directions received.
g. Activate and deactivate traffic overload circuits.
h. Report to DOCC and Operation and Maintenance
elements the status of transmission facilities for operational direction and management.
i. Substitute equipment or circuits for maintenance
purposes or to isolate communications faults.
j. Performs required administration and record
keeping.
t restoration purposes, and
from service for mainteone of the tools available
2-2. Functions of a TCf
The major functions of personnel assigned to a DCS
Station TCF are summarized as follows:
a. Coordinate with the DCA Operations Control
transmission facilities and interpearing at the TCF, as well as the
extension of communications facilities provided by or
users of the DCS.
priori& and estabdirection, coordinaout-of-service transthe DCS station.
2-3. General TCF Responsibilities
Each Technical Control Facility is responsible for
maintaining continuity of service through effective
operation and maintenance of the DCS facilities within its operational area. This includes Patch and Test
Facilities, and attended and unattended facilities.
General functional responsibilities of TCF personnel
include but are not limited to the following:
a. Restore or reroute disrupted circuits over available facilities in accordance with the predetermined
restoration priority. The technical control that first
becomes aware of the outage is responsible for initiating the restoration and follow through actions concerning the restoration, until such time as service is restored.
b. Report all information pertinent to an outage.
c. When a disrupted segment of a circuit is on a disrupted multiplexed group, coordinate with the Facility
Control Office (FCO) for that segment to determine if
that segment of the multiplexed group is being restored.
d. Direct localization of troubles found or reported,
when necessary refer troubles to the responsible office.
e. Provide progress reports, as required, in restoration activities.
f. Carry out technical control functions in locating
and clearing trouble in outside plant cable and facilities.
g. Conduct in-service quality control tests and assist
in out-of-service testing and/or circuit realignment.
A. When a failure occurs on a multipoint circuit, determine and remove the affected segment. Restore the
circuit in accordance with priority assignment.
i. Review the temporary path change record regu
2-1
TM 11-5895-1012-10
larly. Take action to restore the circuit to its normal
path.
j. Notify the Circuit Control Office (CCO) when a
circuit has been changed considerably or has been restored after prolonged outage so that the circuit can be
retested end-to-end.
k. Respond to the operational direction and technical supervision of higher level control offices.
l. Consult with the higher level control office before
taking action that would disrupt service, except in
emergency situations when the action cannot be deferred.
m. Prepare and forward reports in accordance with
current directives.
n. Establish written local operating procedures for
coordinating with commercial agencies, users, and
other sections within the DCS Station.
o. Review circuit performance and initiate action
with other stations to correct problems or unsatisfactory conditions. Refer conditions and problems beyond
the capability or outside the authority of the TCF to
the appropriate control center or operation and maintenance activity with recommendations for resolution.
p. Arrange for coverage of partially attended or
unattended stations when a need is anticipated or
when an emergency or channel shortage arises.
q. Activate on-call or overload circuits.
r. Coordinate and expedite activation of special circuits called for in special instructions.
s. Maintain up-to-date contingency actions to be
taken in the event of significant communications failure to ensure continuity of service.
t. Exercise extreme care so that service is not inadvertently interrupted.
u. Report immediately all instances of negative or
untimely response from PTF’s, operation and maintenance activities, other TCF’s, or commercial agencies.
v. Make recommendations which would improve the
TCF either as a facility or from an equipment standpoint.
w. Maintain and properly label equipment and
patch bays.
x. Assure that all technical controllers are trained
in authorized procedures and that these procedures are
followed.
y. Maintain a current reference library readily accessible to all technical controllers.
z. Publish and post notices concerning additions, de=
letions, or changes in circuits; special tests on circuits
or equipment; changes in frequency assignments, etc.
2-4. TCF Responsibilities to Subscribers
or Users
or user access to the
A TCF which provides
DCS has additional responsibilities which must be satisfied. The service TCF personnel are responsible at all
2-2
have a circuit which
stored or rerouted over new facilities tested from endto-end.
f. Notiy the appropriate control office
will not be available at the time and date
tenance work, and other sched
tions.
2-5. Additional Responsibilities
ties at the station as follows:
a. Technical Control Facility. TCF
sponsible for:
(5) Radiated power.
(6) Transmission levels.
c. Radio Receiver Station.
TM 11-5895-1012-10
the identification of harmful inAssistance in the evaluation of jamming sigof incoming signals and making
ons concerning frequency changes.
2-6. Special Assignments
implementation of the overall control plan
requires that certain TCF's be designated as Facility
Control Offices, Circuit Control Offices, and Intermediate Control Offices (ICO). Control office designaCommunications
based on recomand vary depending upon the length and complexity of
the overall transmission facility, types of transmission
media involved as well as the communications and
testing facilities available. The responsibility for overall service still rests with the DOCC. However, the specially designated TCF's assist in carrying out the mis-
exercises technical supervision over specified DCS
wideband facilities. The FCO is selected on its accessibility to the systems and stations under its control and
orderwire capabilities to each Intermediate Control
Office and to other TCF's within the designated area
of responsibility. When a TCF is designated as a FCO
it will have technical supervision over all links under
its control. All TCFs and PTF’s along the route, as
well as all connected TCF's and PTF’s. These stations
will respond to the FCO’s technical direction. TCF personnel assume the following added responsibilities
when the TCF is designated as a Facility Control Office:
n operational status of assigned facili(1)
ties.
(2) Direct remedial action to correct service degradations which affect system performance and user
service.
(3) Direct restoral and reroute action.
(4) Direct special testing to isolate system and cirto determine capability of the system to
or uniqueservice requirements.
adjacent TCF’s and PTF’s whenever a
that may have an effect on the opera-
ters within established standards.
(7) Establish procedures for subordinate stations
to forward to the FCO test and alignment data;
analyze that data looking for trends toward adverse
system performance; forward performance data to the
DOCC and operation and maintenance activities.
(8) Implement transmission facility activation,
deactivation, and configuration change schedules.
Notify appropriate elements when implementation is
completed or delayed.
(9) Maintain appropriate logs and system performance records.
(10) Report assigned facility operation status to
higher levels of authority and respond to their direction.
b. Circuit Control Office. One TCF through which a
circuit passes is designated in the technical service order as the CCO. CCO personnel are responsible for the
following actions:
(1) Activation of the circuit from end-to-end and
ensure that the service order is completed 72 hours before the scheduled service date.
(2) Direct overall lineup and subsequent testing
to ensure that the circuit meets the parameters established for the grade of service.
(3) Advise the appropriate elements of any circuit
restrictions which might effect service.
(4) Prepare and implement out-of-service quality
control test schedules.
(5) Record and maintain on file the required test
summary.
(6) Initiate isolation and correction of any trouble
discovered as a result of quality control testing.
(7) Coordinate end-to-end testing whenever the
circuit routing is substantially changed or it has been
restored after a prolonged outage.
(8) Make certain that all patches and cross-connects are removed when the circuit is discontinued.
(9) Report to high level of authority, uncooperative action on the part of any TCF, PTF, or commercial
agency during circuit activation or deactivation.
(10) Coordinate restoration of assigned circuits including coordination of reroute action.
(11) Direct and coordinate troubleshooting to isolate and clear the trouble which is disrupting service.
(12) Restore the circuit to its normal path as soon
as possible. This is done through constant review of
temporary path changes.
(13) Keep all elements advised as to progress of
restoration work.
(14) Establish procedures for handling and recording service interruptions and bring any conditions beyond the capability of the TCF’s, PTF's and/or CCO to
the attention of the appropriate element.
d. Intermediate Control office. If the circuit layout
is such that the FCO or the CCO is not in the best posi
2-3
TM 11-5895-1012-10
tion to test and coordinate activities of intermediate
TCF's, another TCF can be designated as an Intermediate Control Office. The ICO will be designated on the
service order at the time of layout and TCF personnel
have the general responsibility of the assigned segment as well as the following:
(1) Conduct in-service testing and take corrective
action in the case of signal degradation, including
those signals not alarmed by pilot frequencies.
(2) Activate, deactivate, and change the circuit in
accordance with TSO's.
(3) Initiate chit
Section II. SYSTEM SERVICE INTERFACES AND TYPES OF SERVICE
2-7. Introduction
In this section
and the types
technical conof service will
troller to make the most efficient use of circuits and
systems available, an understanding of the overall
DCS and the facilities serviced is necessary. In addition to understanding the make-up of the DCS, the
technical controller should be familiar with the transmission media used; communications facilities involved; the facilities which use the DCS mainline
trunk routes as a transmission path; and the types of
signals which are generated by these facilities. The information covered in this Election is listed below together with appropriate paragraph references:
a. DCS common user network (para 2-8).
b. Transmission media (para 2-9).
c. Communications facilities (para 2-10).
d. Relay Centers (para 2-11).
e. Automatic Voice Network (AUTOVON) (para
2-12).
f. Automatic Digital Network (AUTODIN) (para
2-13).
g. Types of signals (para 2-14).
2-8. DCS Common User Network
a A common user network is one that provides a set
number of channels of voice or data communications
for use by an even larger number of users on a shared
basis. A user of a communications network can be a
person making a telephone call; a communications center originating or receiving many teletype messages,
data or facsimile signals; or a solitary teletypewriter
maintaining contact with another like machine. The
originating user am be linked to another activity within the same geographical area or in another geographical area. The point to remember is that the available
channels of communications are shared by all or they
are for "common usage”. Within the DCS the majority
of the available channels are for common usage. Dedicated circuits, which make up the remaining channels,
are established to support the traffic originating at
dedicated facilities which provide communications of
common interest, high volume, or priority traffic cus2-4
2-9. Transmission Links and Media
(1) High Frequency Radio. This media can cover
TM 11-5895-1012-10
Figure 2-1. Example of a world-wide common user network.
2 - 5
TM 11-5895-1012-10
distances up to 6,000 miles. The ground distance between stations is dependent upon the equipment selected and station design. A limitation on high frequency radio is the small number of multiplexed channels which can be carried, usually 4 voice frequency
(2) Line of sight Radio. These radio links operate
in the very high frequency, ultra high frequency or microwave frequency regions. There must be 8 line of
sight path between the transmitting and receiving stations, however, this limitation is overshadowed by the
capability of such links carrying a high density of multiplexed communications channels.
(3) Tropospheric Scatter Radio. This type of
media relies on the forward scatter technique or propagation. Tropospheric scatter can cover distances between 100 to 500 miles and carry a large number of
multiplexed channels, depending upon system design.
This media of transmission is also referred to as overthe-horizon propagation and does not require a line-ofeight path between stations.
(4) Satellite Radio. The distances covered by this
media depends upon how high above the earth the
satellite relay station is positioned. The distance between earth stations usually vary between 2,000
and 6,000 miles. The transmission link is capable of
carrying many multiplexed channels. The main limitation is that the channel capacity and position of the
satellite relay station cannot be upgraded or changed.
(5) Metallic Links. Metallic links can be coaxial
cable, paired cable, or open wire. A metallic link can be
of all one type or by use of interfacing equipment be a
mixture of two or all three of the types. A metallic
cable link can be either submarine or landline. Metallic
systems can carry a low density or a high density of
multiplexed channels depending on the equipment and
the type of cable selected and user requirements. The
major limitation is in the construction of such systems.
Right-of-way must be arranged and cable or wire laid
to make the physical connection between the two
breakout points. An added factor is the maintenance,
and when needed, the repair of the outside plant facilities.
b. Transmission links utilizing line of sight paths,
tropospheric scatter, and metallic media can cover the
required distance between breakout points directly or
may require intermediate stations to span the distance
between the two stations providing the breakout capability. These intermediate facilities are called relay
stations for radio systems and repeater stations for
metallic systems. In either case the relay or repeater
station performs the same function It will equalize
and simplify the incoming signals to permit the retransmission of a signal that, as near as possible, duplicates the original transmitted signal.
c. Referring to figure 2-1, the common user net2-6
work depicted can be made up of all the types of tram
mission media described above. In addition, any one or
all of the transmission links shown could have one or
mom intermediate relay or repeater stations as part of
the link, or span the distance without the need of these
stations. The type of equipment selected and the make
up of the transmission link is determined by the distance between breakout points, strategic and economic
factors, and the technical parameters required to provide the appropriate type and grade of service to the
users.
2-10. Communications Facilities
(fig. 2-2)
The communications facilities, which when connected
together to form the worldwide common user system
can be classified as tributary stations, major relay stations, or minor relay stations.
a. Tributary Stations. A tributary station provides
communications services, telephone, teletype, data
etc., to activities located at the same base or installation. It is not a requirement that tributary stations be
located on a base or installation. It could be positioned
in a civilian community where there is a concentration
of DCS users. The equipment installed at the tributary
station is compatible to that of the relay station or
message switching center that provides access to the
DCS. In figure 2-2, the facilities located at Camp P
and Camp J, are tributary stations located on the in
stallation. From the tributary station, lines extend
outward to the user equipment. This equipment can be
a single teletypewriter; banks of teletypewriters located in the installation communications center; data
terminals; a computer; a facsimile machine; and the installation telephone exchange. The telephone exchange further extends the service of the tributary station to each authorized telephone user on the installation. Stations PDQ and LMN are tributary stations
not located on an installation, but in a town or city in
which there are a number of authorized users
requiring access to the DCS. The transmission link between the tributary station and its associated access
station to the DCS can be direct or require the use of
repeater or a relay station.
b. Major and Minor Relay Station Tributary station access to the DCS is through a relay station,
Traffic flows through the access relay station onto the
system to the distant tributary station. Relay stations
are classified as major or minor depending upon their`
position in the DCS.
(1) Major Relay Station. In figure 2-2, DCS
Station ABC can be classified as a major relay station.
It is situated at a nodal (or junction) point of two or
more DCS subsystems. In addition to passing traffic
originating at or destined for a connected tributary
station, it also acts as a circuit switching station. The
TM 11-5895-1012-10
Figure 2-2. Interconnection of communications facilities, simplified diagram.
2-7
TM 11-5895-1012-10
station is located at the junction of Government owned
Systems #1, #2, and #3 of the world-wide network, and
is also an access point to leased circuits carried over a
commercial facility, and a Government owned satellite
system. Signals entering ABC on System #3, as an
example, from tributary station LMN or beyond DCS
Station XYZ, and not destined for a connected tributary station, would be switched to leave the nodal
point on Government System #1 or #2, the commercial
facility, or the Government satellite system. The
switching can be accomplished on a channel, group or
supergroup level. DCS Station ABC provides many
routing capabilities for signals originating at an associated tributary station, including interconnection of
users located at any of the serviced tributary stations.
(2) Minor Relay Station. DCS Station XYZ (fig.
2-2) can be classified as a minor relay station. The
amount of installed equipment would be much less
than that of DCS Station ABC since it is not at a nodal
point. It services only one tributary station, and provides access only to the East or West on System #3.
Message Relay Center Interface
(fig. 2-3)
It is not feasible (economically or practically) to have
each teletypewriter user connected directly to every
other users machine. Economic interconnection is established through a complex subsystem network of
message relay centers. The worldwide DCS is used as
the vehicle to transmit messages from one user to another. Individual teletypewriter signals are multiplexed into composite signals which are then transmitted over the DCS system voice channels. So that
every teletypewriter user can transmit to any other
user, a system of message relay centers has been established to switch (or relay) the messages from one system to another and move it from the originator to the
addressee as quickly as possible. The message relay
center may be an activity serviced by a tributary station or a tributary station itself. Message relay centers
are classified into three categories: manual, semiautomatic, and automatic.
a Manual and Semiautomatic Message Relay Centers. The manual and semiautomatic message relay
centers employ the torn tape method of operation. An
operator tears the incoming message tape off of a receiving machine, reads the routing indicator, and hand
carries it to the transmitting position. This is a relatively slow method since the speed of passing a
ge tape through the office is dependent upon the
and accuracy of the operator in reading the rout+
ing indicator, carrying it to the transmitting position,
and preparing it for retransmission. The semiautomatic message relay center speeds up the retransmission process by having an automatic numbering process and tandem transmitter distributors with auto2-11.
2-8
matic switching between them.
b. Automatic Message Relay Centers. There is no
need for operator intervention during normal operation of this type of message relay center. Messages
am automatically passed, via cross office equipment
from the receiving machine to the transmitting position, renumbered and retransmitted to the next relay
center or to the addressee. This permits rapid relay of
messages through the relay center. Delay is only dependent upon the speed at which the cross-office
equipment operates. So that this facility can operate at
maximum speed and efficiency, there is a need to
maintain precise accuracy in the production of the
original message tape, and high quality of the DCS circuits over which the message travels.
2-12. AUTOVON INTERFACE
(fig. 2-3)
a. The worldwide DCS main-line trunk routes pm
vide the transmission path for voice frequency communications over the Automatic Voice Network
(AUTOVON) another DCS subsystem. The basic
objective of AUTOVON is to establish a common-user
automatic switching network that provides worldwide
compatibility, reliability, flexibility, and greater survivability of telephone communications. The voice
communications capability is provided between Department of Defense users and between Department of
Defense users and certain non-DoD users. The system
is established primarily for voice communications, but
it is capable of handling graphic and data transmissions on a user-to-user basis. It is capable of handling
secure communications when the appropriate equipment is installed at user locations. For operational and
control purposes, the AUTOVON switch has a built-in
TCF which functions as a tributary station to a DCS
major or minor relay station.
b. The Automatic Voice Network is intended to
offer identical services worldwide to its users. Services
that are available to users system wide are as follows:
(1) Normal Service. It provides the capability for
direct dialing from one user to another on a worldwide
basis. In instances where limited trunking facilities
are available, the user will place the call through a
local operator or a Dial Service Assistant.
(2) Four-Wire Service. Selected subscribers to
AUTOVON are provided with a special I-wire telephone for direct access to the network. Data
subscribers are provided access to specially conditioned AUTOVON data circuits. The signalling from a 4wire instrument is dual-tone, multifrequency. The
four-wire service subscribers can also be provided with
up to three levels of precedence for pre-emption of
lower level precedence calls when necessary.
(3) Off-Hook Service. The off-hook service sub
scriber is immediately connected through the network
TM 11-5895-1012-10
Figure 2-3. Subsystem interface with the DCS.
to a predesignated subscriber as soon as the handset is
lifted from the cradle.
(4) Special Networks. These special networks may
allow complete privacy to specially designated users or
allow them access to the entire AUTOVON network.
These special networks fall into two categories:
(b) Category 2 provides special treatment to
users within a special interest community. This community of special interest can be within one geographical area or worldwide. General purpose subscribers can
be prevented from calling into category 2 networks
and category 2 subscribers can be denied access to the
general purpose network.
c. Normally connection through the AUTOVON
from user to user will be completed in about 4 seconds.
Difficult connections may take up to 10 seconds
through unusual or complex routing. This is switching
time only and excludes the time required to dial. Offhook service connections are normally established in
less than 2 seconds. So that designed speed and quality
of service can be realized, AUTOVON designated DCS
circuits must be maintained at a high quality.
2-13. AUTODIN Interface
(fig. 2-3 and 2-4)
a Another communications subsystem interface
which a technical controller must be aware of and
familiar with is the Automatic Digital Ne
(AUTODIN). AUTODIN interstation trunks are sup
plied by the worldwide DCS main-line trunk routes.
The transmission quality on the AUTODIN trunks is
the responsibility of the DCS Station Technical Control Facility. The technical control personnel monitor
all incoming dc circuits and breakdown voice
frequency telegraph carrier into individual dc circuits.
These circuits are then extended to the AUTODIN
switch. Like the AUTOVON, the AUTODIN Switching
Center has a built-in Technical Control Facility for operational and control purposes.
b. AUTODIN Is a store and forward switching
network for the transmission of digital data. The
AUTODIN is a high speed, flexible, computer controlled network which provides the Department of Defense and other Government agencies with digital
communications. The flexibility of AUTODIN is
illustrated by the following capabilities:
(1) Processes traffic on a store and forward basis
between two widely separated users.
(2) Sends and receives traffic to and from users at
transmission rates between 75 and 2400 baud and between AUTODIN switching centers at rates up to
baud.
(3) Accepts traffic from teletypewriter, punched
card terminals, magnetic tape terminals, and computers.
2-9
TM 11-5895-1012-10
Figure 2-4. AUTODIN interface with the DCS.
2-10
TM 11-5895-1012-10
(4) Exchanges traffic between users whose equip
ment operates at different speeds and use different
codes and formats.
c. The AUTODIN interface with a DCS Station is
illustrated in figure 2-4. AUTODIN tributary stations
are connected to the AUTODIN Switching Center
(ASC) directly or via AUTODIN conditioned trunks of
the Automatic Voice Network (AUTOVON). The ASC
is connected for transmission to another ASC via the
DCS Station which acts as the gateway to the DCS.
The traffic is cleared through the station and routed
out on predetermined and preconditioned circuits over
cable, radio, or satellite systems. These circuits can be
over Government owned facilities or over leased facilities.
d. The AUTODIN Switching Center can be connected to another ASC over the AUTOVON as a
primary route or, in the event of a failure of a primary
route, as a backup circuit through the establishment of
on-call patches. In addition, users of AUTODIN who
do not require full time access to the ASC can be connected to the switching center over AUTOVON on a
call-up basis. In cases where AUTODIN is routed over
AUTOVON for restoral or for non-full period users of
the AUTODIN to gain access to the ASC, it is the
responsibility of the technical controller at the ASC to
establish the path. The controller dials up the distant
ASC or user, establishes voice contact, makes the required equipment connections to the circuit, and then
turns the circuit over for digital communications. After restoral of normal routing or at the end of the user
real-time schedule, the originating technical controller
coordinates the release of the called-up circuit.
2-14. Types of Signals
A technical controller can expect to find signals from
any type of terminal equipment passing through the
TCF. The signals from these equipments include but
are not limited to dc teletype loops, speech, data,
facsimile and voice frequency carrier telegraph
(VFCT). The signals may be broken down to a channel
level or pass through the Technical Control Facility at
the group or supergroup level. The terminal equip
ment generating the data, facsimile and VFCT signals,
produce a composite tone in the voice frequency range
and the tones are then normally transmitted over a
voice frequency channel that has a range from
300-2800 Hertz (Hz) (2500 Hz bandwidth, (nominal 3
kHz channel)) or 300-3400 Hz (3106 Hz bandwidth
(nominal 4 kHz channel)). There are some instances,
such as with television or other wideband signals,
where the composite tones require a wider bandwidth.
In these cases two or more adjacent channels are
specially prepared for transmission of the wideband
signal.
a. The voice frequency speech signals can originate
from 2-wire or 4-wire instruments with almost any
type of signaling, The power for this circuit is generated as the user speaks into the telephone and the
frequency complexity of the signal is that of ordinary
speech.
b. DC teletype signals originate at the teletype
machine and consists of a series of coded pulses, (each
one unique to a keyboard character) where a direct current is either flowing or not flowing. The teletype
signal can be passed through the station as dc to
another teletypewriter, but most usually it is inputed
to voice frequency carrier telegraph equipment where
the pulses generate tone signals for one channel of the
VFCT composite output tone.
c. Voice frequency carrier telegraph systems accept
from 2 to 16 or more teletypewriter signals and multiplexes the tones generated by each teletype signal into
a composite “tone package”. Each teletypewriter signal
occupies a different portion of the frequency spectrum
of the tone package, which is then transmitted over a
single voice frequency channel.
d. Data and facsimile terminal equipment functions
in the same manner as a VFCT terminal. In converts
the intelligence from mechanical linkage or light
intensity into a unique data stream or series of tones
which can then be transmitted over a single voice frequency channel. Data signals can originate at a single
data terminal or from an AUTODIN Switching Center.
e. At the Technical Control Facility the controller
monitors and tests these signals at the voice frequency
level, except in those instances where a dc teletype
loop appears at a dc patch panel. Various types of test
equipment, which will be discussed later, are available
for the technical controller to check the quality and
level of the signals passing through the station.
Section III. THE TECHNICAL CONTROL FACILITY
2-15. General
a. The Technical Control Facility (fig. 2-5) is that
element of a communications network that provides
the technical control, interfaces transmission elements
of the DCS, and interfaces the user with the System.
The management of the communications paths is done
at the TCF and subordinate Batch and Test Facilities.
As noted in the previous section, the communications
paths can be over any of the following transmission
media singly or in serial combinations:
(1) Submarine cable.
(2) Land-line cable or wire circuits.
(3) High frequency radio circuits.
(4) Tropospheric scatter radio circuits.
2-11
TM 11-5895-1012-10
(5) Line-of-sight radio circuits.
(6) Earth satellite radio circuits.
b. The Technical Control Facility functions to provide technical direction, coordination, technical supervision of transmission media and equipment, quality
control, communications restoral and status reporting.
These functions are accomplished with the following
five basic operations:
(1) Patching (r&oral, test, monitor).
(2) Coordination (to far-end, to user, to maintename).
(3) Testing (insertion of a known signal with
measurement for frequency, level, distortion, etc. on
an out-of-service basis).
(4) Monitoring (measurement of existing circuit
conditions or traffic, without insertion of a test signal,
on an in-service basis).
(5) Reporting (circuit and system status to users,
adjacent TCF’s, circuit distant end, operation and
maintenance activities, etc., as well as all required repetitive reports).
c. Normally, the TCF is collocated with a tape relay
and switching center, and/or a carrier terminal facility, but it may be located with either a radio station or
telephone facility. The choice of location is usually
based on a study of all factors involved in site selection. By choosing to collocate the Technical Control
Facility with the tape relay or switching facility eliminates the necessity of providing additional intrastation links. All circuits, regardless of the media used
and type of signal, are available at jack appearances at
the TCF. These appearances provide the flexibility required by a TCF. There are exceptions to this rule
where circuits transit the station on a through group
level. However, there are group access points, which
allows access to the circuits being carried on a through
group for testing purposes. These access points normally located at the multiplex equipment outside the
TCF, can also be used as patching points for restoral or
rerouting of groups in the event of system failure.
2-16. Technical Control Configuration
Block Diagram
(fig. 2-6 and 2-7)
a. General. The block diagram illustrates the interrelationship among the major equipment of the Technical Control Facility together with the terminal
equipment. Although the Technical Control Facility of
many DCS Stations may not require access to all transmission modes shown in figure 2-6, the TCF configuration should be essentially the same, whether the station is located at a transmission nodal point or terminal point. The block diagram includes all major equip
ment and patch facilities which are involved in the
overall technical control function, however, all items
will not necessarily be located with the immediate TCF
2-12
operating space, as indicated on the diagram. Figure
2-7 shows a typical floor plan for a Technical Control
Facility.
b. Primary Patch Bay.
(1) Dc and Digital. The dc and digital primary
patch bays are those areas within the TCF where dc
and digital user circuits can be patched, monitored and
tested. Signals may be high or low level and baud rate
depending on the user terminal equipment.
(2) Voice Frequency (VF). The vf primary patch
bay is that area within the TCF where voice frequency
circuits can be patched, monitored and tested. Signal
will have varying levels and signalling schemes depending on the user terminal equipment.
c. Circuit Conditioning Equipment. Circuit conditioning equipment, such as amplifiers, pads, hybrids
etc., signalling equipment, digital line interface units
(DLIU), and circuit ancillary equipment is so installed
and wired into the TCF so that it will appear between
the primary and equal level patch bays.
d. Equal Level Patch Bay. The equal level patch bay
is that area within the Technical Control Facility
where voice frequency channels at the standard Test
Level Point (TLP (OdBr send and receive)) utilizing
standard in band signalling can be patched, monitored
and tested.
e. Group Patch Bay. The group patch bay is that
area where multiplexed groups (usually 12 channels
can be patched, monitored, and tested.
f. Coaxial Patch Buy. The coaxial patch bay is that
a associated with the TCF where signals requiring
distribution via coaxial cable can be patched, monitored, and tested. Signals which require coaxial cable
distribution include supergroup, baseband, high speed
Time Division Multiplexed signals, etc.
g. Dc Circuit Bay (Low/Level) and Digital Patch
Buy. The dc circuit and digital patch bays are those
areas within the Technical Control Facility where low
level analog or digital data circuits can be patched
monitored and tested
h. Patch Panel Appearances. Patch panel appear
ances are furnished and installed for the following
(1) Allow for substitution for those units which
are out of service because of test and maintenance of
the facility.
(2) Allow for substitution of equipment strings
(circuit or wideband segments) as they occur between
the primary and equal level patch panel appearances.
i. Time Division Multiplexer Equipment (TDM). The
time division multiplexer equipment is a technique to
accept various digital signals (both data and teletype)
with different bit rates and combine them into a single
high bit rate stream for transmission. The demultiplexer section reconstructs the signals at the same
nominal rate at which they entered the multiplexer
This equipment can be used in tandem to accommo-
TM 11-5895-1012-10
Figure 2-5 Technical Control Facility, interface diagram.
2-13
TM 11-5895-1012-10
Figure 2-6. Technical Control Facility, configuration block diagram.
2-14
TM 11-5895-1012-10
date a wide range of data rates to produce a single
serial stream of information, with its associated timing.
j. Pulse Code Modulation Equipment (PCM). The
pulse axle modulation equipment normally accepts the
analog signal (the modulating signal) and samples it at
a predetermined rate. The sample is then quantized
and coded so that each element of information consists
of differing numbers of pulses (marks and spaces).
This equipment generally uses an eight bit sample
rate.
k. Modems.
(1) Digital Modems (VF). This is a modem which is
used to convert direct current signals appearing on the
digital patch bay to the analog form for appearance on
the equal level patch bay. This equipment requires a
nominal bandwidth of 4 kHz
(2) Special Digital Modems (Group). Input to this
modem is in digital form from the digital patch bay.
Its output is analog form and appears on the group
patch bay in the standard frequency division multiplexed group frequency bandwidth of 60 to 108 kHz.
(3) Special Modem (Supergroup). Input to this modem is in digital form from the wideband user/switch
or TDM. Its output in analog form appears on the supergroup portion of the coaxial patch bay in the standard FDM supergroup frequency bandwidth of 312 to
552 kHz.
2-17. Voice Frequency Circuits
a. General. All voice frequency (vf) users including
AUTOVON, AUTODIN, and AUTOSEVOCOM
switches, communications centers, PABX's, local
switchboards and tactical multiplex equipment access
the TCF by way of the Primary Patch Bay. Four-wire
fixed station multiplex equipment utilizing 2600
Hertz signaling access the TCF by way of the Equal
Level Patch Bay. All conditioning and signalling
equipment required to achieve compatibility between
users and the transmission media is electrically connected between the Equal Level Patch Bay and the Primary Patch Bay. The Primary Patch Bay terminates 2,
4, 6, or 8 wire user circuits. The Equal Level Patch Bay
serves at the principal point of interface and restoration in the Technical Control Facility. Circuits appearing at the Equal Level Patch Bay appear as 4-wire balanced pair circuits (AUTOVON switch circuits having
Pilot Make Busy capability appear as five-wire circuits). The Equal Level Patch Bay is the zero (0) test
level point in the station, that is, OdBr send and receive. DCS standard supervisory signals appear as
2600 Hertz tones at the Equal Level Patch Bay.
b. Circuit Descriptions. The following is a list of the
various types of voice frequency circuits which may be
commonly found appearing in the Technical Control
Facility. A TCF may service other circuits which are
not included in the following list. A description of each
circuit follows in the paragraph indicated.
(1) Two-wire voice user with 20 Hertz signalling
(para c below).
(2) Two-wire voice user with loop signalling (para
d below).
(3) Two-wire voice user with E&M signalling (para
e below).
(4) Two-wire voice user with standard integral signalling (para f below).
(6) Four-wire user with standard integral signalling (para g below).
(6) Four-wire user with 20 Hertz signalling (para h
below).
(7) Four-wire user with loop signalling (para i below).
(8) Four-wire data user cable to TCF (para j below).
(9) Two-wire or four-wire voice user using nonstandard in-band signalling (nonstandard signalling
unit at user terminal) (para k below).
(10) Four-wire user with DX signalling (para l below).
(11) Four-wire PBX trunk to AUTOVON (PBX
cable to TCF) (para m below).
(12) Four-wire data user with DX signalling (para
n below).
(13) Two-wire PBX cable access line (two to four
wire conversion at PBX) to local AUTOVON switch
(para o below).
(14) Four-wire AUTOVON subscriber telephone
cable to TCF (loop resistance less than 700 ohms) (para
p below).
(15) Four-wire AUTOVON circuit (remote twowire PBX subscribers) (para q below).
(16) Four-wire AUTOVON special grade circuits
(AUTOVON subscribers (data) and inter-switch
trunks) (para r below).
(17) Four-wire AUTOVON voice grade circuits
(para s below).
(18) Voice and telegraph users connected to High
Frequency radio transmission media (pars t below).
(19) Four-wire voice frequency carrier telegraph
(para u below).
(20) Fixed station multiplex interconnection (para
v below).
(21) Non-DCS multiplexer user to DCS user on
base, or using DCS transmission media (para w below).
(22) Four-wire entrance toll cable (para x below).
(23) Four-wire connections to High Frequency radio systems (para y below).
c. Two- Wire Voice User With 20 Hertz Signalling
(fig. 2-8
). The users for this circuit are either a
two-wire switchboard or an individual two-wire user
using 20 Hertz ringing source. This circuit provides
echo suppression and control in order to minimize
2-15
TM 11-5895-1012-10
Figure 2-7. Technical Control Facility, typical floor plan.
2-16
TM 11-5895-1012-10
Figure 2-81. Typical voice frequency circuits (sheet 1 of 5).
2-17
TM 11-5895-1012-10
Figure 2-82. Typical Voice Frequency Circuits (sheet 2 of 5)
2-18
TM 11-5895-1012-10
echoes arising from four-wire to two-wire conversions.
The circuit makes an appearance at the Primary Patch
Bay by way of outside plant cables. Between the Primary and Equal Level Bays, conditioning is provided
by pads, amplifiers, and two-wire/four-wire terminating sets. Signalling conversion is provided by E&M/20
Hertz converters and 2600 Hertz signalling unit. This
configuration can apply to “hotline” or dedicated circuits, orderwires, and switchboard trunk circuits.
d. Two-Wire Voice User With Loop Signalling (fig.
2-8
). The users for this circuit a either two-wire
switchboards or two-wire individual users which use
loop signalling. The circuit is the same as that in c
above with the exception of using E&M/dial loop signalling converters instead of E&M/20 Hertz convert
ers.
e. Two-Wire Voice User with E&M Signalling (fig.
2-8 ). The user for this circuit is either a two-wire
mitchboard or individual user with E&M signalling. It
is noted in this circuit that a separate cable is used
in the on-base cable to carry the E&M (dc) lea& from
the user location through the Primary Patch Bay to
the SF 2600 unit. Conditioning items are two
wire/four-wire terminating set, repeat coil, echo sup
pressor, and pads and amplifiers for level adjustment.
These configurations have applications as user to central officer inter-connections and user-to-user link.
f. Two-wire Voice User with Standard Integral Signalling (fig. 2-8
). The user of this circuit is a two=
wire w who has 2600 Hertz inband signal incorporated into the terminal telephone equipment. A two
wire/four-wire terminating set performs the necessary
hybrid functions, and pads and amplifiers are installed
for level adjustment. This circuit is for special application to users with this requirement and may have an
echo suppressor added if so specified.
g. Four-Wire VF User with Integral Signalling (fig.
2-8 ). This user provides his own 2600 Hertz inband signalling at the user station or the circuit may
be a data circuit. In any cam, no signalling conversion
is required at the Technical Control Facility. Between
the Primary and Equal Level Bay appearances, repeat
coils, pads, and amplifiers are supplied for conditioning
and level adjustment Amplitude equalizers may be required depending on the service.
h. Four-Wire VF User with 20 Hertz Signalling (fig.
2-8 ). The users for this circuit are either a fourwire switchboard or an individual four-wire user which
uses 20 Hertz signalling. A four-wire physical circuit is
used for the on-base cabling. Conditioning between the
Primary and Equal Level Bays consists of pads and
amplifiers for level adjustment. E&M/20 Hertz converters and SF 2600 units are required for telephone
signalling conversions. This configuration can be applied to dedicated lines, and orderwire circuits.
i. Four-Wire VF User with Loop Signalling (fig.
2-8 ). The users of this circuit can be either a fourwire switchboard or individual user which uses loop
signalling. The circuit flow is the same as in h above
except that an E&M/DC loop converter is used instead
of an E&M/20 Hertz converter.
j. Four-Wire Data User Cable to TCF Without Signalling (fig. 2-8
This circuit is for high speed
data users, AUTODIN interswitch trunks, and data
lines for secure voice circuits. In addition to level adjustment, amplitude or delay equalization units may
be required in the strings of conditioning equipment.
k. Two-Wire or Four-Wire Voice User Using NonStandard Inband Signalling (fig. 2-8
). After entering the TCF by way of the Primary Patch Bay, the
non-standard inband signalling is converted to standard inband signalling before it appears at the Equal
Level Bay. This is accomplished by using a signalling
unit compatible to the non-standard inband signal being received, converting it to E&M signalling, and applying the E&M pulses to the SF 2600 unit through a
pulse link repeater.
l. Four- Wire PBX or User with DX Signalling (fig.
2-8 ). The users for this circuit are either au
AUTOVON PBX access line or an AUTOVON fourwire user. DX-1 signal units and repeat coils are used
at the user locations either to conserve cable pairs or
where loop resistance exceeds 50 ohms. If the AUTOVON switch is off base, the circuit proceeds to the
Equal Level Bay with the necessary conditioning and
telephone signal conversion units located between the
Primary and Equal Level Patch Bay appearances. If
the AUTOVON switch is collocated on-base, the circuits do not access the Equal Level Patch Bay, but
after passing the Primary Patch Bay, the circuits are
conditioned for proper levels and E&M signalling, and
make another appearance at the Primary Patch Bay
and connect to the AUTOVON switch.
m. Four- Wire PBX or User with E&M Signalling
to AUTOVON (PBX Cable to TCF) (fig. 2-8
). This
user circuit is similar to the circuit described in l above
except there is no requirement for DX-1 signal units
at the user or the TCF. This is because the user and
TCF are closely located and plant cable pairs with less
than 50 ohms loop resistance can be used.
n. Four-Wire Data User With DX Signalling (fig.
2-8 ). This circuit is similar to makeup to that discussed in l above, with necessary amplitude or delay
equalization devices. The circuit is of high speed data
quality but can be called up by way of the AUTOVON
switch when required.
o. Two-Wire PBX Cable Access Line to Local
AUTOVON Switch (Two to Four-Wire Conversion at
the PBX) (fig. 2-8 ). This circuit involves connection of a two-wire on-base telephone switchboard to an
AUTOVON switch which is also located on the same
base. This PBX (access circuit appears only on the Pri2-19
TM 11-5895-1012-10
Figure 2-83. Typical Voice Frequency Circuits (sheet 3 of 5)
2-20
TM 11-5895-1012-10
Figure 2-84. Typical Voice Frequency Circuits (sheet 4 of 5)
2-21
TM 11-5895-1012-10
mary Patch Bay and does not access the Equal Level
Patch Bay as the circuit involved does not go off base.
A two-wire/four-wire terminating set shall be required
at the PBX location. Normally the E&M leads will be
extended as shown in figure 2-8 and described in e
above. Where the loop resistance exceeds 50 OHMS, signal extension units (DX) shall be required at the PBX
location and at the Technical Control Facility. Split
controlled echo suppressors, pads and amplifiers when
required are inserted into the circuit as shown.
p. Four-Wire AUTOVON Subscriber Telephone Cable to TCF (Loop Resistance Less Than 700 Ohms) (fig.
2-8 ). This AUTOVON telephone is located less
than 700 ohms from the collocated TCF and AUTOVON switch. In this case the circuit accesses the Primary Patch Bay, connects to repeat coils and level adjustment equipment, and returns to the Primary Patch
Bay with E&M lead appearance and then proceeds to
the collocated AUTOVON switch.
q. Four-Wire AUTOVON Circuit (Remoter TwoWire PBX Subscribers) (Fig. 2-8
. This trunk circuit originates at the AUTOVON switch collocated
with the Technical Control Facility. The circuit interconnects at the Equal Level Patch Bay to transmission
media for service to remote two-wire PBX AUTOVON
subscribers. provision is made for an echo suppressor
when the PBX is two-wire. This circuit appears on the
Equal Level Patch Bay and pads and amplifiers are
provided for level adjustment. As this circuit is designated to interconnect with multiplex facilities, a pilotmake-busy (PMB) circuit is used as follows:
(1) The Group Pilot Control (GPC) alarm circuit
furnishes output leads (one for each channel in the associated group) which are grounded when group failure occurs. The GPC alarm indicates normal operation
with an "open" circuit condition.
(2) On each channel associated with group using
the GPC alarm function, the GPC alarm leads are extended to the sleeve conductor of the associated Equal
Level Patch Bay channel line jack.
(3) On each AUTOVON trunk circuit the input
to the sleeve conon the Equal Level
Patch Bay equipment jack. The coil of the PMB relay
has sufficient voltage connected to it to operate the relay when ground is applied to the GPC output lead.
(4) The PMB relay operates as follows:
(a) Open the E lead connection from the SF unit
y after the alarm condition
50 seconds depending upon
conductor to the Pri-
2-22
(AUTOVON Subscribers (Data) and Inter-Switch
Trunks) (Fig. 2-8 ). This circuit operates the same
as that described in q above except that delay equalization devices are provided for data use.
s. Four-Wire AUTOVON Voice Grade Circuit (Remote AUTOVON Four-Wire User) (fig. 2-8
). This
circuit operates the same as that described in q above
except that the circuit connects to remote AUTOVON
four-wire users.
t. Voice and Telegraph Users Connected to High
Frequency Radio Transmission Media (fig. 2-8
Voice and telegraph using high frequency radio transmission for long distance communications accesses the
Primary Patch Bay of the Technical Control Facility as
audio or dc circuits. The circuits shown illustrate the
setup for high frequency independent sideband transmission made up of four 3-kHz bandwidth channels.
The typical four channel system depicted is equipped
for three voice channels (A2, B1, B2) and one VF tone
package consisting of 16 date channels (Al). Line conditioning equipment for these circuits before they access the Equal Level Patch Bay includes: a telephone
terminal set or channel for each of the three voice circuits and regenerative repeaters and/or isolation relays
for the dc circuits. Separate pads and/or amplifiers are
provided for the VF tone package before it accesses the
Equal Level Patch Bay.
u. Four-Wire Voice Frequency Carrier Telegraph
(VFCT) Packages (fig. 2-8 ). This circuit consists of
multiple teletypewriter signals which enter the Technical Control Facility at the Primary and Dc Patch
Bays and are then combined into a "tone package” at a
voice frequency carrier telegraph (VFCT). The VF tone
package employs a nominal 4-kHz channel bandwidth
and appears at the Equal Level Patch Bay as an audio
signal. Although VF level control can, in most cases,
be achieved by the VFCT equipment, pads and amplifier may be installed in the circuit prior to accessing
the Equal Level Patch Bay, if necessary.
v. Fixed Station Voice Frequency Multiplex Interconnection (fig. 2-8 ). This is the normal configuration of a frequency circuit between the Equal
Level Patch Bay and the fixed station multiplex equip
ment. The only interface requirements are level control and the PMB circuit which is described in q above.
w. Non-DCS Multiplex Users to DCS User On-Base
or Using DCS Transmission Media (fig. 2-8 ). This
circuit is provided to interface a tactical multiplex using a non-standard method of telephone signalling to
user circuits conditioned for the standard signalling
interface at the Equal Level Patch Bay. After an appearance at the Primary Patch Bay, a signal converter
compatible with the signal used by this multiplex is installed to change the nonstandard tone signal to E&M
type of supervision. These dc signals are converted to
single frequency tones by a signal frequency unit; a
TM 11-5895-1012-10
Figure 2-85. Typical
Typical Voice Frequency Circuits (sheet 5 of 5)
2-23
TM 11-5895-1012-10
pulse link repeater may be required far transposition
of the E&M leads. Level control is maintained, as required, by pads and amplifiers as indicated.
x. Four-Wire Entrance Toll Cable (Fig. 2-8
This circuit is required for interconnection at the Primary Patch Bay with any long distance physical commercial toll circuit. Level adjustment using pads and
amplifiers is located between the Primary and Equal
Level Patch Bays.
y. Four-Wire Connections to High Frequency Radio
Systems (fig. 2-8
). The remote high frequency
radio transmitter and receiver sites may access the
Technical Control Facility by either microwave radio
or cable intersite links. Since the send and receive
channels are one-way and receiving combining is used
on the carrier telegraph system, all channels access the
Primary Patch Bay regardless of the intersite transmission media. Similar connections are made for these
channels with pads and amplifiers for level adjustment, before the circuits access the Equal Level Patch
Bay.
2-18. Digital Data Circuits
Existing digital dc circuits consist of a wide variety of
modulation rates, modes of operation, unit codes, and
circuit configurations. The variety of circuits and various equipment arrangements at the user end has
caused nonstandardization of dc Technical Control
Facilities.
a. Signal Levels. All dc circuits appearing at the dc
Equal Level Patch Bay are configured for low-level
polar operation.
(1) Only low-level operation is used within the
black patch, test, or conditioning equipment area within the TCF. Only low-level operation is used within a
red equipment area when such an area is required to
support the TCF. All teletype and data end equipment
used within the Technical Control Facility is configured for low-level operation in order to provide flexibility during equipment substitution and to facilitate
conversion to encrypted operation at a later date.
(2) Unencrypted data orderwire and reporting circuits may be required at some locations. These circuits
are intended for encrypted service at a later date and
are configured and routed in-station so that installation of the cryptodevice will not require major rewiring of the circuit.
b. Basic User Circuits. The total user requirements
are reducible to four basic types, allowing simplicity
and standardization, at the digital dc patch panel and
improve efficiency. The four basic types of user-access
circuits described below are shown in figure 2-9.
(1) Digital Data User-Access Circuits Via Dc
Transmission Mode. All user-access lines entering the
Technical Control Facility by way of the dc transmission mode makes an appearance on the dc portion of
2-24
the Dc Primary Patch Bay. The signal from the Dc Primary Patch Bay, if nonstandard or if isolation is required, is converted to standard low-level and then accesses the Dc Equal Level Patch Bay.
(2) Digital Data User-Access Circuits Via VF
Transmission Mode. All user-access lines entering the
TCF by way of VF transmission mode is treated as a
VF circuit until converted to standard polar dc signals.
The standard low-level polar dc then accesses the Dc
Equal Level Patch Bay. At this point the dc circuit is
either looped back to the local user or reconverted to
voice frequency for transmission over long haul transmission media.
(3) Technical Control Access Digital Data Circuits. All TCF dc circuits (teletype orderwires, report+
ing circuits, etc.) appear directly at the Dc Equal Level
Patch Bay.
(4) High Speed Data. All high speed (above 1200
baud) dc circuits except those requiring coaxial type
wiring access the Dc Equal Level Patch Bay directly
without prior access through the Digital Line Interface
Unit. All high speed dc line outputs and modems pm
vide the standard low-level polar signal.
c. Timing, Control, and Alarm Circuits. Provisions
are made on the Dc Equal Level Patch Bay for patching and testing of all timing, control, and alarm circuits.
d. Testing of Dc Signals. All dc circuits appear at
the Dc Equal Level Patch Bay. Dc signals which
appear at the Dc Primary Patch Bay will differ in coding schemes and baud rates. Testing of all dc circuits
will be performed on a high impedance basis. Signal
levels applied to the high impedance test equipment in
all cases are equal no matter what the coding scheme
or baud rate.
2-19. Wideband Facilities
(fig. 2-6)
a. General. Facilities for monitoring, testing, and
patching of wideband circuits, multiplex groups,
supergroups, and basebands are provided at stations
where required as outlined below. Wideband jackfields, in bays separate from VF and dc jackfields are
provided for this purpose.
(1) Wideband circuit monitoring and testing
facilities are provided at all stations which control
such stations. At stations where alternate routes or
spare equipment for such circuits are available, patching facilities to permit reroute or restoral is also included within the TCF.
(2) Group, supergroup, and baseband monitoring,
testing, and patching facilities are provided at all stations having more than two multiplex link terminals,
and are sometimes provided at smaller stations to
meet special requirements. Normally, at stations having only one or two multiplex link terminals, the jack
TM 11-5895-1012-10
Figure 2-9. Standard dc/data access circuits
multiplex equipment is adequate
rgroup, and Group Patching Con(1) The capability for patching among like and un-
of group or supergroup connectors is required.
t which use the standard
but have different levels,
ncies can be made compatthrough the use of concertain types of multiuse nonstandard frey allocation plans and therefore cannot be
ed at the group or supergroup level even with
. .
Appearances for such equipment may be
wideband jackfields for monitoring and
testing only.
(2) DCS standard levels and impedances for
group, supergroup, and baseband have been
established. However, them are still types of multiplex
equipment in use which have been designed to operate
at other levels and impedances. In stations where
multiplex not conforming to DCS standard levels and
impedances exists or is programmed for installation, a
local standard is established. The term standard when
used in this manual refers to that standard which is in
use, either the DCS standard of local standard of levels
and impedances.
(3) A stand&-level jackfield is provided. It includes appearances of groups, supergroups, and base
bands of all multiplex equipment operating at the
standard levels and impedance, group and supergroup
connectors designed to operate at those levels and impedances, and one end of each conditioning string.
c. Conditioning Chains or Strings. Conditioning
equipment chains or strings are usually made up of the
following types of components. Not all components are
required for every string. Only those components
necessary to match the levels, impedances, and pilot
frequencies of a particular type of nonstandard multiplex to the station standard is included in each string.
(1) Impedance matching equipment is required to
2-25
TM 11-5895-1012-10
match a variety of impedances encountered in different types of multiplex equipment, including 600,
150, and 135 ohms balanced and 75 ohms unbalanced.
Not all of these will ordinarily be found in the same
station.
(2) Level adjusting equipment is used to coordinate the levels of groups, supergroups, and basebands of nonstandard multiplex with the standard
levels. This equipment includes adjustable attenuators
and wideband amplifiers. The impedance matching
feature described above may be combined with the attenuators or amplifiers or both in integrated assemblies.
(3) Group pilot frequency conversion equipment
is used to change nonstandard group pilot frequencies
to the standard frequency without change in level.
This equipment removes the incoming group pilot,
converts it to the desired frequency, and reinserts it at
the same level as the incoming pilot. The reinserted
pilot level will track any variations in the incoming
pilot level with an accuracy of ±0.5 dB. Pilot alarm
equipment to indicate variation in pilot level beyond
allowable limits is usually associated with the frequency conversion devices.
2-20. Internal Systems
Systems internal to the Technical
Facility include all of the nontraffic handling
subsystems, which include but not necessarily limited
to those described in the following paragraphs.
b. Intercommunications (Intercom) System. The
intercom system provides technical coordination internal to the Technical Control Facility and to support
ing and using agencies located in the vicinity of the
TCF Intercom service is provided through the use of
existing administrative telephone circuits which contain the intercom feature, and through the application
of a multistation intercom system. The intercom system shares common equipment and operator panels
with the orderwire system. The number of intercom
station locations varies with the operational mission
and actual TCF configuration. The audio and dc patch
bays are equipped with a sufficient number of intercom stations to allow access from each working
location. As a minimum, one intercom station is pro
vided for every three patch bays.
c. Alarm System. An alarm system is provided to
alert the Technical Controller and maintenance technicians of equipment degradations or failures that affect communications circuit status. Information pro
sented by the alarm system initiates prompt action
toward the restoration or rerouting of circuits and the
repair of faulty equipment. Display of alarms is in a
central location provided in the Technical Control Facility operating area. Parallel presentation of portions
of the alarm display is also required in maintenance
2-26
and operating areas remote from the
(supervisory. maintenance, or service areas). The
amount and type of equipment necessary to satisfy
this requirement is dependent on the TCF size and will
vary from site to site.
(1) All alarm outputs are accessible at the main
frame. According to equipment types, alarms are designated as “go-no-go” or analog types (for adaptation t
more sophisticated monitoring). The alarm display ix
cludes but is not limited to the following as applicable
to the station configuration:
(a) All radio paths.
(6) Cable carrier systems.
(c) Data circuits.
(d) Circuits having an alarm feature.
(e) Common equipment units which could affect
service.
(f) Low transmitter output.
(g) Low receiver input.
(h) High received noise on the radio channel.
(i) Failure of standby equipment.
(j) Failure of primary equipment.
(k) Signal level, high or low.
(l) Power being used <primary, secondary
emergency, auxiliary, or battery).
(m) High or low power voltage.
(n) Open fuse alarm.
(o) High or low pilot frequency level.
(p) Failure of line signalling supply.
(q) Low fuel supply for generator.
(r) Open door or window (at unattended
station).
(s) Failure of obstruction or warning light.
(t) Change in waveguide pressurization.
(u) Fire in equipment area.
(v) Failure of environmental control system.
(2) The alarm system provides for incremental es
pansion. The system is usually so designed that activations, deactivations, and changes of transmission systems, TCF subsystems, and circuits can be accommodated without affecting the operation of the
basic system. The system is usually broken down into
two subsystems:
(a) A local equipment and functions alarm subsystem.
(b) A remote station equipment and function
alarm subsystem.
d. Orderwire System. An orderwire network is provided for efficient TCF procedures. Information
regarding circuit and facility statu
work, and maintenance and trouble co
mitted over this network. Voice and da
up the orderwire network and provid
means of coordination between two or
tween a TCF and associated PTF, and
and some special communicati
use
TM 11-5895-1012-10
and type of orderwire circuits required at TCF's vary
from site to site as dictated by station size, mission,
and location.
2-21. Station
a. Types. Different types of cabling are necessary
for interconnection of the various equipment and keying lines with the Primary and Equal Patch Bays
as well as the transmission media equipment and subscribers.
(1) Voice frequency lines generally use appropriate sizes of shielded, single pair wires.
(2) Direct current keying lines use individually
shielded pairs.
(3) Standard power cables are used to distribute
primary power to equipment
(4) Coax and twinax are used for high speed data
MODEMS.
b. Routing. Cables are usually installed in one or a
combination of the following four methods; overhead
inclosed ducts, overhead open racks, cellular flooring,
and floor trenches.
c. Shielding. Prevention of mutual interference between circuits that carry dc keying signals and circuits
that carry vf signals is accomplished by shielding the
dc keying circuits. Whenever feasible, separate racks
or ducts should be used for each type of circuit.
2-22. Distribution Frames
a. All in-station lines, equipment and channels, plus
external cable pairs, terminate on a distribution
frame. A main distribution frame is used for terminating outside lines and an intermediate distribution
frame is used to terminate in-station lines. However,
in the interest of simplification and conservation of
apace it is common practice to use a combined distribution frame within the Technical Control Facility.
The distribution frame is made up of vertical and
horizontal terminating blocks. The vertical blocks,
used for terminating outside lines, are provided with
protective devices to shield the cables and associated
equipment from high voltages surges. The horizontal
blocks are used to terminate the in-station cabling.
Cross connections are made on the distribution frame
to obtain the desired circuitry.
b. Jack appearances, in the Primary and Equal
Level Patch Rays, are terminated on the combined
distribution frame as are the equipment associated
with collocated facilities.
c. Temporary arrangements of circuits and equipment can be provided in the patch bays with the use of
patch cords. However, all permanent changes should
be made on the combined distribution frame in order
to minimize the requirements for patch cords in use at
any time in the Technical Control Facility.
d. All cable runs and equipment connections are
made to provide transmission security. The criteria are
based on the concept of separation of red and black circuitry within the TCF and the DCS Station. In order to
accomplish this separation, there are two separate
distribution frames provided. One to carry the red circuits and the other to carry the black circuits.
(1) Red Frame. The red frame is used to make
crossconnections between red circuits, patch panels,
and equipment, Red circuits are those circuits which
carry or are cleared to carry, clear text, classified
traffic. The red frame has a horizontal aide and a
vertical side like any other combined distribution
frame. Termination blocks are mounted on both tides
of the red frame. The vertical side is used to terminate
equipment, such as relay center equipment (send and
receive); the clear side of the COMSEC devices (send
and receive); the red side of battery isolation relays
(send and receive); and for red circuit control, switching, or monitoring devices. The horizontal side is used
to terminate the red patch panels and the positive and
negative rectifiers used to furnish battery. If any
traffic-carrying circuits which are approved for
handling clear text classified traffic without COMSEC
devices are in use, the lines will be connected to the
vertical side of the red frame. The cables which are
used to connect the items listed above to the red frame
are permanently connected to the left side of the vertical blocks and to the bottom side of the horizontal
blocks. Cross-connections are made as required to connect battery, equipment, patch panel jack appearances, and COMSEC devices together to form a circuit.
(2) Black Frame. The black frame is used to make
cross-connections between black circuits, patch panels,
lines and equipment. Black circuits are those circuits
which carry encrypted traffic or unclassified, clear
text traffic. The black frame is the same configuration
as the red frame, having a horizontal side and a verticd side. The horizontal side is used to terminate the
audio and dc patch panels of the TCF and the positive
and negative battery supplies. The vertical side is used
to terminate the following items: all landlines, both
audio and dc; the black or encrypted side of COMSEC
devices; the black side of battery isolation relays; and
any black circuit control, switching, or monitoring devices used in the TCF. The various items are cross-connected as required to form the desired circuitry.
2-23. Power Facilities
a. General. Each Technical Controller must be
aware of power facilities used to provide primary and
auxiliary, and emergency lighting power at the DCS
Station. A detailed discussion of power facilities and
equipment is given in paragraphs 2-24 through 2-28.
b. Primary Power. The term primary power is used
at DCS Stations to denote the primary ac power source
to the DCS Station under normal operating conditions.
2-27
TM 11-5895-1012-10
c. Auxiliary Power. Auxiliary power is provided at
each DCS Station to replace all or part of the primary
power in case of failure. This auxiliary power is usually
supplied by engine-generators and storage batteries.
These engine-generators are installed and operated as
part of the DCS Station. Auxiliary power is the
currently-approved designation for back-up or alternate power sources frequently referred to as emergency
power sources.
d. Emergency Lighting Power. Emergency power
requirements at DCS Stations are normally limited to
battery-powered lighting systems for use while
auxiliary power equipment is being activated after
failure of the primary power supply. These emergency
systems are normally automatically activated immediately upon failure of the primary or auxiliary
power supply, and are removed from service as soon as
primary or auxiliary ac power is restored.
2-24. Classes of Power
Station power is divided into four classes as follows:
a. Class A Primary Power. A primary power plant
which provides an essentially continuous supply of
electrical power.
b. Class B Auxiliary Power. A standby power plant
to cover extended outages (usually days in length) of a
primary power plant.
c. Class C Auxiliary Power. A quick start (10 to 60
seconds) unit(s) to cover short-term outages (usually
hours in length) of a primary power plant.
d. Class D Auxiliary Power. An uninterruptible (no
break) power unit(s) using stored energy to provide
continuous power within specified voltage and frequency tolerances.
2-25. Types of Ac Power
AC power is available in many different forms (voltage,
phase, and frequency). The type required by a particular DCS Station is determined by the equipment installed at that DCS Station.
a. Frequency. All ac powered communications
equipment manufactured in the United States is available in models that require an input frequency of 60Hertz (Hz). Some equipment is also available in models
that can operate on ac power supplied at different frequencies, such as 25 or 50 Hz. Most foreign-made
equipment is designed to operate only from 50 Hz
power sources. Since most of the equipment at any
DCS Station will be manufactured in the United
States, the primary ac power source should be 60 Hz.
So that equipment designed for other frequencies can
be operated, a rotary or solid-state static type converter is used to change the frequency of the primary
power.
b. Voltage. Most communications and test equip
ment is designed to operate on 120 volts single phase.
2-28
However, equipment that requires large amounts of
power, such as a high-powered radio transmitter,
generally is designed to operate on 240 or 480 volt,
three phase power. These are nominal voltages, and a
variation of ±5 percent usually can be tolerated.
(1) Some equipment is built with power input
transformers, that have tapsbrought out to terminals.
These taps are on the primary (input) side of the transformer, and are marked with a common voltage value.
For example, a transformer in a piece of equipment
may have-either three or five taps. If there are three
tap, they usually are marked 105, 115, and 125 volts;
if there are five taps, they are usually marked 105,
110, 115, 120, and 125 volts. Transformers for higher
(2) Three-phase power requirements at DCS
Stations are usually at a nominal 120/208 volt potential. However, some RF power amplifiers etc., may
be designed to operate on different voltages, such as
240 or 416 volts. These voltages are supplied by
special transformer configurations.
c. Phase. Equipment that requires 120-volt input
power is generally designed for single-phase power
most equipment that requires 240-volt input power is
designed for three-phase power. The generation of
three-phase power is accomplished by three separate
induction coils in the generator. The method of
connecting these three coils results in various
configurations, and may be arranged to give different
voltages in the range of 208 to 480 volts. The threecoils, and the individual phases they produce, are
separated by 120 degrees so that there is equality between the three phases. Higher powered generating
plants normally produce three-phase power. The
majority of the DCS Station equipment uses only
single-phase power. Distribution of primary power
within the station is important; therefore, disparity
between loads on individual phases creates problems
and should be balanced within reasonable limitations.
2-26. Generating Equipment
a. General. The engine-generator sets provided at
the DCS Stations are used for primary or auxiliary
power requirements. For use as either a primary power
source or an auxiliary power source, the electrical
characteristics are the same. Normally, the only difference is that more sets of equipment are required if
they are used to produce power at all times. For
example, the general practice for auxiliary power is to
provide two complete sets of power generating equipment. When they are used to provide all power for the
station, at least three complete sets of equipment are
required.
b. Engines. The engine, or prime-mover is designed
nave more horsepower than the generator rating;
TM 11-5895-1012-10
this provides for losses and the capability to maintain
constant speed at full load. The engine must also be
equipped with a governor to maintain a constant output when the generator is connected to a varying load.
Diesel and gasoline engines are used as prime movers.
(1) Diesel Engines. Both low-speed and high-&
diesel engines are used as prime movers. High-speed
diesel engines can be installed at less cost than the lowspeed, heavy-duty diesel engine, but not operated or
maintained as economically.
(2) Gasoline Engines. Gasoline engines are used as
prime movers to drive generators of limited capacity
to supply power on an intermittent or purely auxiliary
basis. They should not be used to drive generators to
supply power continuously or over extended periods of
time, because the useful life of a gasoline engine in
continuous service is relatively short. The initial cost
of a gasoline engine is much less than that of a diesel
engine, but maintenance costs are higher.
(3) Gas Turbines. Gas turbines have the advan-
tages of light weight, quick starting, and acceptance of
load without the usual warmup period. A disadvantage
is their high fuel consumption rate.
2-27. Power Distribution
a General. As previously indicated, most DCS
Stations have at least two separate power sources, primary power and auxiliary power. These two power
sources must be selectable; that is, switching and other
necessary mechanisms must be provided to permit
station personnel to select the desired source. Changeover must be fast, in fact, it should be possible to
change power sources without any break in the power
supply to the communications equipment. When primary power fails without warning, this may not be
possible, but activation of the auxiliary power and connection to the communication should comply with the
prescribed standards. In addition to the power changeover requirements, normal operation requires that the
power demands within the station be balanced among
the phases of *phase primary power supplies.
b. Switchboards and Automatic Transfer Panels.
EL3Z0055
Figure 2-10. Double bus arrangement and automatic transfer panel, wiring diagram.
2-29
TM 11-5895-1012-10
Automatic transfer panels provide an automatic
switching arrangement designed to maintain power
with minimum interruption for the operation of DCS
Station equipment. Transfer panels must handle
separate sources of power. In the case of a combination
of generators, or of generators and commercial power
(fig. 2-10). the desired power source can be selected to
permit rotation of the engine-generators. A time-delay
relay will postpone switching the load to any enginegenerator until the engine reaches its recommended
operating temperature. If there is a gradual decrease
in voltage, voltage-controlled relays will switch the
load to an alternate source of power.
c. Station Power Panels. The main power distribution panels are determined by the individual station
requirements. When two or more power sources are
operated in parallel, a master control switchboard pro
vides a means for measuring the output frequency,
voltage, and current. These measurements generally
are made at the main bus bars, and thus indicate the
total load and combined power supplied.
d. Distribution for DCS Stations. DCS Stations receive power from an external distribution system or
local Class A primary power plant. Distribution within
the DCS Station begins at the main power panel and
extends to the operating equipment. Subpanels, transformers, and circuit breakers may be included in the
distribution circuits. Communication equipment in the
station may he divided into two or more major groups.
Each major group of equipment is connected to the
main power panel. Radio transmitting stations have
the largest and most complex power installation of the
DCS. The output voltage and the configuration of
engine-generators is connected to transformers, or
direct& to the bus bars on the main switchboard.
Distribution lines from the power panel to operating
equipment are installed in floor trenches, in ducts, or
on cable racks.
e. Simplified Power Distribution. The following is a
description of the simplified power distribution shown
in figure FO-1. Many different arrangements are
possible at all stages, and each station’s requirements
will determine the best arrangement for the particular
installation.
(1) Primary power at 2400 volts is available from
the commercial power source or from either of the two
generators installed at the station. At the main switchboard, located in the utility building with the generators, power from any one or more of these sources
can be applied to either or both of the power distribution cables to the operations building. In this
example, all switching is performed at 240 volts, after
reduction by deltadelta transformers. In some cases,
these switching functions may be performed at the
2400-volt level and the transformer located in the
operations building.
2-30
2-28. Uninterruptible Power Supply
(UPS)
(fig. 2-11, 2-12)
TM 11-5895-1012-10
generator load and cranks the diesel engine with a
minimum drop in frequency during the transition.
After the diesel engine comes up to speed, it assumes
the load and continues to produce power to meet the
load requirements. During diesel operation, the commercial power is constantly monitored for voltage and
frequency. When the commercial power returns to the
correct voltage and frequency, normal operation is
resumed, that is the commercial line contractor closes,
the magnetic clutch is deenergized, and the diesel
engine shuts down after a cooling-off running period.
The electric motor and flywheel continue to operate.
Figure 2-12 shows the unit in standby operation and
figure 2-13 shows the unit online.
b. Another method for providing uninterruptible
power which is being utilized in overseas AUTODIN at
the Automatic Digital Message Switching Centers
(ADMSC’s) is shown in figure 2-13. This type of a UPS
may also be found at DCS Stations other than those
collocated with an ADMSC.
Figure 2-11. Uninterruptible power supply in standby condition.
Figure 2-12. Uninterruptible power supply in on-line condition.
2-31
TM 11-5895-1012-10
Figure 2-13. ADMSC uninterruptible power system.
2-32
TM 11-5895-1012-10
(3) The battery bank consists of 120 2-volt singlecell units connected in series.
(4) There are four motor-generator units operating at any time, but a total of five units are available
for operation. In case one of the operating units fails,
the standby
unit is automatically turned on,
.
synchronized, and switched on the line within 10 seconds. The UPS is designed so that, under normal operating conditions (four units on-line), each M/G set is
operating at approximately 60 percent of rated load.
Since the units are rated for a 25 percent overload last
ing at least two hours, the UPS system is capable of operating with only two functioning M/G sets for brief
periods, and with three sets for indefinite periods.
This degree of redundance provides the critical portions of the ADMSC with great reliability.
(5) Under normal operating conditions, four M/G
sets are connected to the critical supply bus and are
equally dividing the system load within their normal
Based on these normal system operating conan automatic power load transfer is accomat the no-break critical supply bus as a result of
one or more of the following abnormal operating system conditions:
(a) Variation of generator output voltage belimits of plus or minus 10 percent of normal
ue of 120/208 volts (sensed by the over and
utput frequency be/2 Hz of the nomiand over frequency
flow as sensed by
(6) The following controls are built into the UPS
to maintain the stabilized power required for the
ADMSC:
(a) Frequency Regulation. The magnetic amplifier type of speed regulator is provided with the dc
motor of each motor-generator unit for controlling the
M/G set speed, which in turn controls the output frequency. These speed regulators offer the advantages of
high corrective output signal (high gain) from a
relatively low level input with associated fact response
to variations in the M/G set speed (frequency). The
speed regulating system consists of a frequency detector, magnetic amplifier control circuit, and a single
phase full-wave magnetic amplifier which controls
excitation of the dc motor.
(b) Voltage Regulation. The generator output
voltage of each motor-generator unit is controlled by
an individual magnetic amplifier type of voltage
regulator.
(c) Additional Controls. In addition to the above
controls, each motor-generator set contains associated
under and over voltage relays, and reverse current relays to monitor operation properly. Activation of any
of these relays will energize the trip circuits of the input and output circuit breakers and remove the associated M/G set from the UPS system.
c. Another method for providing uninterruptible
power to critical loads is the solid-state static-type
rectifier-charger-battery-inverter system shown by the
simplified system block diagram in figure 2-14. This
is a modularized redundant system each module consisting of a rectifier-charger unit, a battery (usually
selected for 15-minute output), and an inverter unit together with appropriate protective devices. Each module has a 100 kilowatt (KW), 125 kilovolt-ampere
(Kva) output rating.
(1) The unit is designed for 200 kilowatt output.
Normally the 200 kilowatt rated load is divided equally between the three 125 Kva units. In case of failure
of any one unit, the unit that has malfunctioned is
automatically removed from operation and the 200
K W load is divided equally between the two remaining
units. Being modular constructed, the module that
failed can be de-energized, the trouble located, and a
new component inserted in the circuitry.
(2) Since this type of UPS has limited operating
experience, records of performance so far have indicated a mean-time-between-failure (MTBF) to be anticipated on the order of 80,000 hours.
2-29. Miscellaneous Power Equipment
a. Storage Batteries. Storage batteries provide a
compact source of dc power for the operation of equip
ment requiring a dc source with a DCS Station.
b. Dry Batteries. Dry batteries are used by DCS Stations to furnish power for certain alarm circuits, emer
2-33
TM 11-5895-1012-10
Figure 2-14. Solid state uninterruptible power system, simplified block diagram.
gency signal lights, test equipment, etc. These batteries are available in various sizes and shapes and in
several capacities and voltages to accommodate a wide
range of uses. Special purposes dry batteries of higher
than normal quality are also available for certain applications.
c. Rectifiers. With an ac power source, rectifiers in
conjunction with appropriate transformers and filters
yield dc power with very little ripple content. Two
common types of rectifiers are those that use electron
tubes and those that use semi-conductors of the disk
type (selenium, silicon, and germanium) as the rectifying medium. Some rectifiers are designed as part of a
specific equipment and some of these cannot be used in
other applications. However, many general purpose
rectifiers are available. In efficiency, rectifier output is
usually from 60 to 70 percent of the input power.
d. Dynamotors. Dynamotors are rotating machines
used to convert dc voltage of one value to dc voltage of
another value and usually are components of specific
equipment Usually, these units have only one set
field coils and each set of armature windings is con
nected to its own commutator. Essentially, dyna
motors are motor-generators in which the motor and
generator windings are wound in the same slot and on
a single common armature.
e. Frequency Changers.
(1) Frequency changers are motor-generator sets
that convert ac of one voltage and frequency to ac of
another voltage and frequency. Frequency changers
are used in DCS Stations to convert the incoming as
frequency and voltage to match the input power re
quirements of certain items of DCS equipment.
(2) The motor-generator sets, depending on the
application, may be driven by either a single or mull
phase induction or synchronous type motor. The driving motor is usually coupled directly to the generator
by a common shaft with both machines mounted on
the same bedplate.
Section IV. REPRESENTATIVE TCF EQUIPMENT
2-30. General
introduction of high-speed data
transmission into the DCS, the term “circuit conditioning” was little used in Technical Control Facilities. As
higher speed data circuits came into wider usage, the
term became increasingly familiar to technical controllers, especially as it applied to circuits obtained from
have an understanding of the requirements for circuit
conditioning and technical information on the equipment required fop circuit conditioning. This section
2-34
will discuss the conditioning equipment found in the
TCF and those other items of equipment which are required to insure circuit performance and to enable the
Technical Controllers to perform the function of the
TCF.
b. Ideally, all transmission systems and the channels of these systems should preserve the fidelity an
amplitude of the original information. However, it is
recognized that in a practical communications system
the information carried over any transmission media
is subject to certain electrical characteristic changes
which result in loss, delay, or distortion of the transmitted information. Even though systems are properly
TM 11-5895-1012-10
in electrical characteristics requiring
conditioning equip
distortion, envelope
delay, signal level changes, and longitudinal balance.
2-31. Circuit Conditioning Equipment
The following is a brief description of circuit condition
equipment used on the DCS and found in the Technical
Control Facility.
a. Pads. Pads, which come in many forms and physical arrangements, are used to attenuate signals within
a circuit. Pads found in telecommunications normally
have the same input and output impedance; however,
they can be designed to match impedance of different
values. The attenuation introduced by a pad is variable, most usually by using different strapping options
to adjust the amount of attenuation in steps of 0.5 dB.
b. Amplifiers. An amplifier is used to increase signal strength without introducing appreciable distortion and to compensate for attenuation of signals on vf
channels. Transistorized and vacuum tube amplifiers
will be found in use on the DCS. Typical amplifiers
used in circuit conditioning have an adjustable gain of
from zero to 35 dB at 1000 Hz, stabilized within ±.2
dB and with a frequency response from 300 to 3400
Hz. Input and output impedances are usually 600 ohms
balanced.
c. Amplitude Equalizers.
(1) Decreased intelligibility in voice circuits can be
caused by the unequal attenuation of different frequencies. For example, as various frequencies pass
along a nonloaded cable, the high frequencies are attenuated more than the lower ones. A l-mile section of
26-gauge high-capacity cable will have a loss of about
1.4 dB at 250 Hz; however, at 3000 Hz, the loss will be
4.5 dB, a difference of 3.1 dB per mile. Therefore, a 4mile section of 26-gauge nonloaded cable will result in
a 5.6 dB loss at 250 Hz and an 18.0 dB loss at 3000 Hz.
The 1000 Hz loss of the 4-mile loop would be 10.7 dB.
The loss across the band, taken at these three frequencies referenced to the 1000 Hz loss, would be 5.1
dB less loss at 250 Hz and 7.3 db more loss at 3000 Hz.
(2) The variation in loss across the band of interest can be compensated for by equalizing. The
equalizing process consists of inserting into the circuit
additional loss which varies with frequency. Sufficient
is added at each frequency to bring the response
across the band within a specified limit referenced to
the loss at a specified frequency, usually 1 kHz.
(3) The amplitude equalizer is any combination of
coils, capacitors, or resistors inserted in transmission
or amplifier circuits to compensate for differences in
attenuation due to differing impedances at the various
frequencies being used. Adjustments are usually provided to accomplish the required equalization.
d. Envelope Delay Equalizers.
(1) There is still another way in which voice-grade
circuits can vary with frequency, and that is in the
velocity of propagation. This variation does not usually affect speech transmission, but it can have an adverse affect on data transmission.
(2) In any circuit there is a finite time interval for
transmission from the sending end of the circuit to the
receiving end. This time is referred to as absolute delay and varies according to the facility used. This time
interval will also vary considerably between various
frequencies in the transmitted band. This means that
the shape of a signal wave at the receiving end can differ to an appreciable degree from that originally applied at the transmitting end. This distortion is called
envelope distortion; and it is measured in microseconds of envelope delay.
(3) Envelope delay distortion is the result of the
deviation of the phase shift from a straight line pattern across the frequency band of interest. In carrier
systems, the variation in time and frequency is caused
mainly by the channel filters. Often additional distortion will be found in the outermost channels of a carrier group. This effect will be more noticeable in some
systems than in others and is caused by the filter cutoff. Normally, it is good practice to avoid the lower
and upper channels of a group or channels adjacent to
pilot tones when channels are being assigned for data
service.
(4) Although delay distortion is found in cable and
channel terminals, it should be remembered that
equipment units, such as repeaters and coils, also
contribute to delay distortion. These units affect the
frequencies below 1000 Hz to a greater extent than
those above 1000 Hz. In calculating the overall
envelope delay of a circuit, the delay inherent in each
equipment unit or line facility section, at specific frequencies, is summarized. When the delay of the
equalizer is added to that of the equipment and facilities, the result should be within the limitations for the
circuit being implemented.
(5) For individual circuits which will be switched
in tandem to form a completed connection, the delay
requirements are much more stringent than for the
overall connection. It is necessary, therefore, that each
circuit, whether an interswitch circuit or access line,
fall within the delay distortion limits established
under the transmission plan for the system involved.
This limit will be stated in the Circuit Layout Record
(CLR) Card for the circuit.
(6) There are two general types of equalizers used
to compensate for the effects of envelope delay. One of
2-35
TM 11-5895-1012-10
these is often called “passive” equalization and the
other "active” equalization. Passive equalization is generally used when referring to circuits where fixed
equalizers are inserted after the required value is computed. Active equalization is commonly used throughout the DCS since such equalizers are continuously
variable over wide ranges and may be simply adjusted
by Technical Control Facility or maintenance
personnel.
(7) Either method of equalization ignores the
absolute delay and only equalizes the relative delay.
Delay equalizers consist of a series of networks with
delay characteristics inverse to those of the circuit
king equalized. Each adjustable section provides sufficient time delay in its frequency band to reduce the
relative delay distortion. One unit in common use in
the DCS reduces the relative delay distortion from 3
milliseconds to less than 80 microseconds from 1000
to 2000 Hz, to less than 260 microseconds from 200 to
1000 Hz, and to less than 500 microseconds from 500
to 600 Hz, and from 2600 to 2800 Hz. It is important
that delay equalizers, particularly passive equalizers,
be placed adjacent to a constant impedance attenuator
or a 600 ohm pad to ensure proper impedance termination.
e. Repeat Coils. A repeat coil is essentially a transformer which will transfer electrical energy from one
source to another without metallic connection between
the circuits. For direct current purposes, it divides the
circuit into two portions. It was from this transfer
function that the term “repeating coil” was originally
derived, since it was used primarily to repeat
information, rather than change voltage or current
values as in power systems. Repeat coils are usually
thought of as impedance matching devices, and the use
of the proper ratio coil is a basic consideration in circuit design
f. Echo Suppression
(1) Echo. A problem, peculiar to long circuits that
terminate in 2-wire instruments, arises from the
velocity of propagation of the various facilities used
for telephone communications. The time required for
the transmission Of voice signals from one point to a
distant termination will vary according to the type of
facility and the overall length of the circuit. If, when a
conversation is being carried on, some part of the
speaker’s voice is returned to him from the distant termination, and the time involved is of sufficient duration, the returned voice signal will have the effect of
an annoying echo.
(2) Echo Tolerance. On circuits that are physically
very short, currents return in such a short period of
time that they take the form of sidetone, which is not
objectionable to the talker. As the time interval increases, currents returned at the same level assume
the form of an echo and become objectionable. Since
2-36
switched 2-wire PBX
tion lines will not be
since they do not have
generate the echo.
g. Telegraph
tronic devices
synchronous o
them prior to retransmission. They are usually constructed to accept various modulation rates
cept signals with up
erative repeaters are
for telegraph circuits,
included as part of original circuit design and a continuing requirement for their use generally indicates
circuit or equipment malfunctions which should be located and corrected and the regenerator removed from
the circuit.
h. Data Modems. This term is a contraction from
the terms modulatordemodulator and all of these
units, which are in use in the DCS in many forms and
configurations, perform the same purpose. They convert digital signals to an analog form in the modulator
portion and convert analog information into digital
form in the demodulator portion. In certain special
cases two modems are used on a back-to-back arrangement to provide regeneration for data circuits. In this
arrangement the output of one modem will be put into
another modem of the same type which will in turn
provide a reshaped and retimed output.
2-32. Wideband Con
a. Wideband condi
egories, the first covering that condition required for
the interconnection of voice frequency multiplex
equipment with different characteristics; the second
for the special conditioning required for 48 kHz channels utilized for wideband data or secure voice transmissions. The standard parameters for voice frequency
multiplex, frequency division (FDM) which have been
established for equipment used in the DCS are:
(1) -34.5 dBr send level input.
(2) -12 dBr receive level output.
(3) 135 ohm impedance (balanced) for both input
and output.
(4) 104.08 kHz pilot.
b. Any new vf FDM must operate at the
TM 11-5895-1012-10
a considerable number of FDM terminals in use in the
DCS which do not utilize the standard parameters.
When interconnection at the group or supergroup level
is required between this nonstandard equipment or
standard to nonstandard equipment special conditioning equipment is required between the multiplexers
for the purpose of level compatibility and impedance
matching. This conditioning equipment is connected
in the same manner circuit conditioning equipment
would be connected on the circuit level.
c. Nonstandard multiplex equipment in use in the
DCS generally does not utilize the same pilot frequency as that used in the standard parameter (104.08
kHz). When multiplex utilizing different pilot frequencies must be interfaced at group or supergroup
levels, pilot conversion is required. This process is referred to as pilot stop and reinjection. Suitable equip
ment must be provided which will stop the unwanted
pilot frequency and permit insertion of the required
pilot frequency. Equipment which perform these functions are commonly called pilot stop and reinjection
filters, and are especially designed for interface at the
pilot frequencies of the multiplex terminals.
2-33. Other Conditioning Equipment
Technical Control Facility personnel will be required
to be familiar with the operational and technical characteristics of other ancillary equipment which may be
required to assure proper operation but which are not
usually referred to as conditioning equipment.
a. Four to Two-Wire Terminating Sets. The four to
two-wire terminating set is used between a two wire
VF channel and a four-wire VF channel. It converts
‘the two wires used for transmit-receive to two wires
for transmit and two wires for receive. Usually the terminating sets also provide impedance matching facilities, enabling 600-ohm 4-wire circuits to be connected to 600- or 900-ohm 2-wire circuits.
b. 600-Ohm Terminations. The normal terminated
impedance of lines used in telephone work is 600
ohms, although some 900 ohm terminations may be
used. When the equipment normally used to provide
proper termination is removed, the Technical Controller must have available a rapid method of terminating
lines so that any test measurement made on the line
will be accurate. A device in common use in Technical
Control Facilities is a terminating resistor which is
usually a noninductive resistor of the proper value
wired across plugs of the same type as those used at
the patch panels.
c. Data Conferencing Network. This device (also
known as a Technical Control Facility Hubbing Repester) enables a predetermined group of users to oper-
ate such that if any one user transmits a message, it is
received by all others in the group. The network allows
any user to transmit as long as only one station is
transmitting at any particular moment. The hubbing
repeater may be used as the interface device between a
Send Only device and several receiving terminals.
d. Passive Peak Limiter. This unit is used to automat&By prevent system overload causes by excessive
transmission levels from the user equipment This
equipment is located on the equipment side of the
Equal Level Batch Bay within the conditioning string
on audio channels.
e. 6-Way 4-Wire Bridge. This unit provides a conferencing capability for 6 each 4-wire telephone circuits.
2-34. Signaling Equipment
The signaling equipment in the Technical Control
Facility provides the means of interfacing ringing and
dial pulse signaling between two different cross-connected channels. The equipment is also used to change
the signal from out-of-band signaling to in-band signaling. Various types of signaling equipment is discussed below.
a. Single Frequency Signaling Units (SFSU). This
equipment is used when it is necessary to convert from
E&M signaling to in-band 2600 Hz or 1600 Hz signaling or in-band to E&M signaling. The SFSU transmit
section converts dc-dialing or supervisory signals present on the M-lead into an amplitude-modulated tone
for transmission over voice frequency channels. The
SFSU receive section converts received amplitude
modulated tones into dc-dialing or supervisory signals
on the E-lead. The state of the E&M leads may be
grounded, +48 vdc, or open circuited. The normal
E&M logic is as follows:
b. E&M/Loop Converter (E&M to Dc). The dial loop
to the E&M converter provides complete access be
tween a central office and a dial user instrument over a
voice frequency carrier channel. There are two versions of this unit as follows:
(1) Central Office Dial Loop to E&M Converter.
This unit receives 20 Hz from the central office and
converts it to an M-lead seizure for input to an SFSU
in the outgoing direction, and presents a closed loop to
the central office when the E-lead from the SFSU indicates an incoming call.
(2) User Dial Loop to E&M Converter. This unit
recognizes a closed loop when the user goes off-hook
and indicates seizure to the M-lead and converts dial
pulses to M-lead pulsing of the SFSU. When a call is
incoming to the user the E-lead causes a 20 Hz ringing
signal to be sent to the end instrument.
2-37
TM 11-5895-1012-10
lead when a signal is received from the ringdown
trunk circuit. It also receives signals over an E-lead
from a signaling circuit and transmits 20 Hz signals to
a ringdown trunk circuit. This equipment can be arranged to operate with signaling frequencies other
than 20 Hz when required.
d. E&M Signal-Lead Extension Circuits (DX1 and
DX2). These signal-lead extensions units are designed
to interconnect two signaling and supervision circuits
when the metallic resistance between users exceeds
operational limits. They are also used to interconnect
an E&M signaling circuit to a distant trunk circuit
which uses single frequency signaling. E&M signallead extension circuits are usually required where the
connecting facility (cable) resistance exceeds 25 ohms
(50 ohm loop). These circuits, which have been coded
DX1 and DX2, are always used in pairs (a DX1 being
connected to the trunk relay circuit and DX2 being
connected to a single frequency signaling unit). They
may be used in any combination, DX1 at one end of the
circuit and DX2 at the other, or with like units at each
end of the circuit. This equipment usually functions
over metallic circuits with loop resistance up to 5000
ohms.
e. Pulse Link Repeater. The pulse-link repeater circuit connects two signaling circuits, using E&M leads,
by converting an incoming E-lead potential to an outgoing M-lead potential in both directions of transmission. This equipment does not connect to or affect the
talking it is connected in the signaling path only.
2-35. Vf and E&M Panels
A voice frequency jackfield is designed as an area in
the Technical Control Facility where voice frequency
circuits and their associated signal and control leads
can be patched, monitored and tested. A patch panel is
a signal unit in the jackfield. There are four types of
voice frequency patch panels in the TCF; the Equal
bevel., the 4-wire, the 6-wire primary, and the 2-wire
primary patch panels. Each panel serves a different
function as described in paragraph 2-17.
a. Equal Level and 4-Wire Primary Patch Panels
(fig. 2-15A) Each Equal Level and 4-wire primary
patch panel contains 12 channels. Each channel occupies a paired jackset (a jack& consists of 4 jacks arranged vertically) of the panel as shown in figures
2-15 and F0-2. The receive circuit occupies the left
jackset (odd numbered jacks) in each paired jackset,
and the transmit circuit occupies the right jackset
(even numbered jacks) of each paired jackset; therefore, the jacks are alternately labeled REC and
TRANS. The top row of jacks are labeled LINE and are
electrically toward the line or away from the Technical
2-38
patch panel has four cable connectors mounted on the
rear of the panel. As shown in figure F0-2, C1 and C3
are used to bring the transmit and receive circuit leads
into the panel. C2 and C4 are known as the normalthrough connectors. The normal-through wiring which
connects the line side to the equipment side of the
panel is routed through these connectors. Thus
is provided to the normal-through connections for future uses, such as automation of the Technical Control
Facility.
b. 6-Wire Primary Voice Frequency Patch Panel
(E&M Signaling). The 6-wire Primary Patch Panel is
panel between them. The E&M patch panel provides
signaling jack appearances for the 12 channels above,
as well as the 12 channels below it. A front view of an
E&M signaling patch panel is shown in figure 2-15B
and the interconnection diagram in figure 2-16. The
odd numbered jacks serve the E&M signaling leads of
the vf above it while the even numbered jacks serve
the E&M signaling leads of the vf panel below it. The
top row of jacks is electrically toward the line, and the
second row of jacks is toward the Technical Control
Facility equipment. As with other patch panels, the
normal&rough connections between the line and
equipment sides of the panel (row 1 and row 2) are
brought out to a normal&rough connector for future
use.
c. 2-Wire Primary Voice Frequency Patch Panel.
This panel is similar to the 6-wire vf patch panel in
that it has four rows of jacks for line side, equipment
side, and monitoring operations. Since it is a 2-wire
panel, it can hold 24 channels. Refer to figure 2-17 for
the interconnection diagram of a 2-wire patch panel.
2-36. Dc Patch Panels
a. Primary Dc Patch Panel.
(1) Panel Description (fig. 2-15). The primary dc
patch panel is that equipment within the Technical
onithe
TM 11-5895-1012-10
A. VF PATCH PANEL
B. E & M (SIGNALING) PATCH PANEL
Figure 2-15. Voice frequency primary or equal level and signaling patch panels. front view
2-39
TM 11-5895-1012-10
Figure 2-16. E&M patch panel, interconnection diagram.
2-40
TM 11-5895-1012-10
Figure 2-17. Two-Wire voice frequency primary patch panel, interconnection diagram
2-41
TM 11-5895-1012-10
Figure 2-17. Two-Wire voice frequency primary patch panel, interconnection diagram
2-41
TM 11-5895-1012-10
Figure 2-18. Dc patch panel, low level receive, interconnection diagram.
2-43
TM 11-5895-1012-10
Figure 2-19. Dc patch panel, low level transmit, interconnection diagram.
2 - 4 4
TM 11-5895-1012-10
radio communication links. The interconnection diagram of the receive panel is show in figure FO-4 and
the interconnection diagram of the transmit panel is
shown in figure FO-5. It can be seen that the wiring is
similar to that previously discussed with the exception
of the cut keys and lamps.
(2) Receive Panel Cut Keys Functioning (fig.
FO-4). When the cut key is operated to the down position, the indicator light is energized and the normalthrough circuit is broken and terminated. The receive
circuit from the LINE side of the panel is terminated
through a 5.6K ohm loop resistor to ground. The tip
lead of the circuit toward the Technical Control Facility equipment is connected to hold battery. The corresponding ring lead is connected to an S lead and output
via connector C1. This S lead provides a through path
for any timing circuits which are present when the cut
key is operated. Contact No. 5 energizes the lamp and
output -48 vdc through the L lead to connector C2.
The L lead provides the capability of energizing
remote lamp to indicate that the circuit is cut.
(3) Transmit Panel Cut Key Functioning (fig.
FO-5). This cut key functions in a similar fashion as
that discussed (2) above, except the loop resistor is
placed in the cut circuit on the EQUIP side of the
patch panel and the hold battery is placed on the LINE
Side.
2-37. Miscellaneous/Interbay Patch Panels and Trunking
a Miscellaneous Patch Panels (fig. 2-21). Miscellaneous (MISC) patch panels are located in the patch and
test bays to provide the flexibility required for test
and monitoring operations. The jacks are wired and
cross-connected as desired by TCF personnel. Figure
2-21 provides a typical functional arrangement for a
miscellaneous panel with 10 lamps in a Technical Control Facility. Figure 2-27 provides the patch panel
interconnection diagram and block terminations. The
patch panel provides such desirable jack arrangements
and functions as 600 ohm loads, parallel jacks, line reversing (tip-to-ring, ring-to-tip), and -48 vdc power.
The -48 vdc power is supplied via jacks 1 of rows 1
and 2. These two jacks are engineered to avoid unsafe
or undesired jacking of the -48 vdc by designing the
jacks for use only with a special double pronged MISC
DC patch cord. Jack 1, row 1 is an undersized jack
which will accept only one prong of this patch cord.
b. Interbay Patch Panels. Each patch and test bay
contains in interbay (INT) patch panel. Interbay
trunks are used to route circuits to other patch bays in
the Technical Control Facility. The various types of
interbay trunks in the TCF are described below.
c. MISC/INT Patch Panels (fig. 2-22). These pads,
located in dc patch and test bays, may be used to perform either an interbay patch panel function or a mis-
cellaneous patch panel function as described in a and b
above respectively. The jacks contain normal-through
contacts for greater flexibility as shown in figure
2 - 2 2 .
d. Interbay Trunking Systems. The Technical Control Facility-has a voice frequency trunking system
and a dc trunking system. The systems are designed to
allow sufficient trunking of circuits from one patch or
test bay in the vf or dc area to any other bay in that
area. The vf and dc interbay trunking systems are not
interconnected and come together only at the intermittent test stations.
(1) Voice Frequency Interbay Trunking System.
The interbay trunking capability in the vf area is provided by interbay patch panels which are mounted in
the bottom of every vf patch and test bay. The panel
has two rows of 24 jacks per row for a total of 48 interbay trunk appearances per bay. The front view of the
panel resembles that shown in figure 2-21, however
the interconnection diagram is that shown in figure
2-23. Terminal blocks Cl and C2 of each panel are
cabled to the vf cdf where the panels are cross-connected to form a series interbay trunking system. The
cross-connecting is done in such a manner that the
same jack in each panel is assigned to the same patch
or test bay. As an example, Jack 2, Bow 2, of every
panel provides a trunk to the same bay. This scheme is
shown in figure 2-24A. TCF personnel can alter the
pattern as desired to provide additional trunks between heavy traffic bays or between bays and test stations. This system provides, generally, only one trunk
between any two voice frequency bays or test stations.
However, the patch cord length usually allows the use
of trunks on either side of the bay providing three
trunks to any one bay by direct trunking.
(2) DC Interbay Trunking System. Interbay trunking capability in the dc area is provided by interbay
patch panels with 48 lamps mounted in the dc patch
and test bays. The panel has two rows of 24 jacks and
two rows of 24 in-use lamps, as shown in figure 2-25.
The panel interconnection diagram is shown in figure
2-26. The lamps are necessary since these cross panels
are interconnected at the dc cdf into a parallel configuration (fig. 2-24B). Every pin on the block of one
interbay panel with 48 lamps IS jumpered to the corresponding pin on the blocks of every second panel (odd
panels form a parallel configuration and even panels
form another parallel configuration). Each parallel
configuration has 48 trunks for a total of 96 trunks in
the dc area. The configurations are referred to as
parallel since an interbay trunk appears on the same
jack of every second INT panel appearance. As an example, Jack 1, Row 1 of one panel is in parallel with
Jack 1, Row 1 of the INT panel two bays away and so
on until all odd numbered and all even numbered bays
are interconnected to form the two separate configura
2-45
TM 11-5895-1012-10
Figure 2-20. Dc Patch Panel (transmit or receive) with cut keys and lamps, front view.
2 - 4 6
TM 11-5895-1012-10
Figure 2-21. Typical miscellaneous patch panel, front view.
2-47
TM 11-5895-1012-10
Figure 2-22. Miscellaneous/Interbay
Miscellaneous
patch interconnection diagram.
2 - 4 8
TM 11-5895-1012-10
Figure 2-23. Voice frequency interbay patch panel, interconnection diagram.
2-49
TM 11-5895-1012-10
Figure 2-24. Typical series and panel interbay trunking systems.
tions. When a trunk is put into use at one bay, the
corresponding in-use lamp will illuminate at all the
interbay panels where the trunk appears to indicate
the trunk is in use.
2-38. Voice Frequency and DC Test Equipment
A major responsibility of Technical Control Facility
personnel is that of monitoring and testing circuits
through the TCF to determine circuit quality and to
determine operating conditions. Additionally, they are
responsible for the rapid identification and isolation of
faulty equipment in order to achieve optimum operating effectiveness. Accordingly, assorted test and monitor equipment is located through the voice frequency
2-50
and dc Technical Control Facility areas to provide an
efficient means for performing these operations. It is
not possible in a general type technical manual, such
as this, to list every specific piece of test equipment to
nomenclature of manufacturers name that could be
found on every TCF in the world. However, instead a
listing by genre is provided. This listing will help you
identify the specific items installed at any TCF and
briefly describe its function.
a. Speaker Panels. Speaker panels are usually
mounted in the bottom of the voice frequency test
bays. These panels are used for aural monitoring of vf
circuits carrying voice signals for the purpose of determining continuity and/or the quality of the speech
traffic. The panel usually includes two amplifier
TM 11-5895-1012-10
Figure 2-25. Dc interbay patch panel with 48 lamps, front view.
2-51
TM 11-5895-1012-10
Figure 2-26. Dc interbay patch panel with 48 lamps, interconnection diagram.
speaker combinations. This allows two independent inputs and outputs. Both inputs are usually wired to
jacks in the miscellaneous patch panel of that particular test bay. For monitoring purposes, either of these
two inputs may be patched via interbay trunks to the
monitor (MON) jacks in the voice frequency patch
panel without degradation or interruption of circuit
operation.
b. Teat Bay Alarm Panels. Alarm panels are usually
mounted at the top of each voice frequency and dc circuit test bay in the Technical Control Facility. The
panel contains one or more rows of lights for the purpose of giving remote alarm indicates for selected
equipment alarm circuits. The alarms circuit to be remoted are usually determined by the Technical Control Facility personnel.
c. Noise Generator. The noise generator gives a flat
response output signal over a wide range of the audio
2-52
spectrum. The output provides a signal to a circuit
under test for measure at the other end with a noise
measuring test set.
d. Dual Channel Dc Amplifier Recorder. The dual
channel dc amplifier recorder is used for simultaneous
reading of two related variables then the variables
need to be analyzed with respect to each other in time,
or when up to two variables need to be permanently recorded.
e. Transmission Measuring Test Set. The transmission measuring test set is used to measure transmission line and system characteristics such as attenuation, frequency response, or gain. It contains a wide
range oscillator, a voltmeter, and a patch panel to
match both the oscillator and the voltmeter to the
various impedances found on the DCS (usually 135,
600 and 900 ohms).
f. Noise Measuring Test Set. The noise measuring
TM 11-5895-1012-10
Figure 2-27. Miscellaneous patch panel with 10 lamps, interconnection diagram.
2-53
TM 11-5895-1012-10
test set is used to measure signal levels, noise level and
volume units (VU). The test set usually has a number
filters for the inputs.
Balance Test Set. The terminal balance
test set when provided* allows for connecting and
switching instruments required for each test without
changing patch cords to the circuits to be tested.
h. Wave Analyzer Test Set. The wave analyzer test
set provides amplitude and frequency information
over a given band of frequencies. The test set can
separate frequency components of an input signal by
means of selectable bandwidths and tuning controls.
i. Patter Generator. The pattern generator is used
to generate a wide variety of telegraph teat signal patterns having predetermined and controllable characteristics and parameters. The unit is used in conjunction with data measuring equipment to test and evaluate the performance of data/TTY systems or equip
ment.
j. Singing Point Test Set. The singing point test set
measures the singing margin of 4-wire transmission
circuits using hybrid terminations by inserting a variable, but known, gain into the circuit until oscillation
occurs. The test set may also be used as a variable gain
amplifier with a maximum undistorted output of
usually 0 dBm at 600 ohms.
k. Impulse Noise Counter. The impulse noise counter counts the number of impulses exceeding a number
of different selected levels for a selected length of
time. The unit provides a readout for each selected level, each giving the number of times an impulse exceeds
the associated adjusted level.
l. Phase Jitter Measuring Set. The phase jitter
measuring set measures the peak to peak phase jitter
indegrees.
m. Transmission Delay
transmission delay measuring test
transmitter and a receiver which is used to measure
signal delay and amplitude versus frequency.
n. Data Analysis. Data analysis test sets provide the
capability for comprehensive analysis and generation
data, start, stop data, and
nitor teleprinters are
used to monitor teleprinter traffic in dc telegraph
loops. A transmitting keyboard is usually included
which, in conjunction with one of the page printers
and utilizing a spare dc circuit, may be used in communicating between Technical Control Facilities for
2-54
the coordination of test fault isolation, or operational
activities. Inputs to the monitor page printers are
usually in the neutral mode. The output of the transmitting keyboard consists of dry contacts. The loop
into which this output is inserted requires the application of operating battery from an external source. The
printers and keyboards may be used in circuit operating at 60, 75, or 100 words per minute when appropriate speed change gears are used. A monitor teleprinter
converter panel is usually provided which will allow
the monitor teleprinter to be used without interupting the circuit being tested. The converter permits the
insertion of the page printer into dc monitor jacks by
converting low level voltage variations into current
impulses needed to drive the page printer.
p. Dual Meter Panels. The meter panel usually contains a high impedance voltmeter and low impedance
milliammeter. The milliammeter is used to measure
the telegraph loop current (high level). Loop current is
measured by patching the meter input into a LINE
MON or EQUIP MON jack at the equal level dc patch
bays.
q. Low Led Meters. These meters, mounted over
various dc patch bays, provide a low level voltage reading when patched into the monitor jack of a dc circuit
via the miscellaneous patch panel. The meters usually
have a zero center scale, with ± 15 vdc full deflection.
r. Reference Tone Generator. The reference
generator provides 0, - 10, -8.7, and - 12.7 dBm
tone levels (or others depending upon the man
turer) to the patch and test bays. These test tone levels
make jack appearances on the miscellaneous patch
panels and then distributed to each patch and test bay.
2-39. Digital
Line Interface Unit (DLIU)
The digital line interface unit is a solid state plug-in
printed circuit module for use as a line isolator and
level converter generally located between the primary
dc and equal level dc patch bays. It accepts a high
level, neutral or polar, or low level signal and converts
it to low level, polar and vice versa. The unit usually
te with either synchronous or start-stop data
up to 2400 baud. Automatic adjustable loop
current regulation for high level output lines is provided as well as no transition/open loop detection and
alarm, build-in loop battery fusing, and output monitor jack and self contained power supply for inter-circuit operation.
TM 11-5895-1012-10
CHAPTER 3
EXAMPLES OF OPERATIONAL TCF'S
Section I. PIRMASENS
3-1. Function
a The Pirmasens TCF is a fixed station technical
control facility containing equipment that provides
termination, interconnection, patching, interfacing,
conditioning, monitoring, and testing of voice frequency (vf) and direct current (dc) communications circuits and signals.
b. The TCF performs the DCS Technical Control
mission for the supervision and control of the transmission media at the Pirmasens Radio Station. This
site is a radio nodal point (fig. FO-6) in the European
Wideband Communication system (EWCS) serving
microwave links to Langerkopf (LKF), Zweibrucken
(ZBN), and Donnersberg (DON). In addition, the site
provides cable links to local vf and dc subscribers.
3-2. Technical Characteristics
equipment are listed below. Detailed technical characteristics of the individual components that are included in the TCF are listed in the appropriate technical manual.
a VF Patching Facilities.
Equal Level Jack Appearances (Full duplex)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1800 ea
6/Wire Primary (cable) Jack Appearances . 96 ea
4/Wire Primary (Cable) Jack Appearances (Full
duplex) . . . . . . . . . . . . . . . . . . . . . . . . . . 720 ea
2/Wire Primary (Cable) Jack Appearances (In
Bays 1.16, 1.17, 1.18)‘. . . . . . . . . . . . . .720 ea
Nominal Signal Level.. . . . . . . . . . . . . . . .0 dbm
Nominal Impedance . . . . . . . . . . . . . . . 600 ohms
b. VF Conditioning and Interface Equipment.
. . . . . . . . . ..<......... 1320 ea
l . . . . . . . . . . . . 200 ea
. . . . . . . . . . . . . . 40 ea
25 Hz Ringing Supply.. . . . .. . . . . . . . . . . .1 set
Signal Supply Unit (2600 Hz) . . . . . . . . . . . . lea
Signal Supply Unit (1600 Hz) . . . . c.. . . . .. lea
Single Frequency Signaling-2600 Hz. . . . .75 ea
Single Frequency Signaling Unit-16 Hz
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 ea
d. DC Patching Facilities.
DC (Equal Level) Jack Appearances (Full duplex).
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 864 ea
DC W/Cut Key (Equal Level) Jack Appearances
(Full duplex) . . . . . . . . . . . . . . . . . . . . . .144 ea
Dc Primary (Cable) Jack Appearances (Full duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 ea
e. DC Line Conditioning Equipment.
Digital Line Interface Units (Full Duplex Shelf
Space). . . . . . . . . . . . . . . . . . . . . . . . . .540 ea
f. Orderwire Capability.
Voice Orderwire Circuits.. . . . . . . . . . . . .20 ea
Dc Orderwire Terminals . . . . . . . . . . . . . . . 24 ea
AC Power Requirements. 208/120 VAC and
380/220 VAC at 50 Hz.
A. DC Power Supplies.
-48 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
-24 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
+130 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
-60 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
+60 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
±6 VDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ea
3-3. Description of the TCF
in a common building with multiplex voice frequency carrier telegraph (VFCT) equipment, and microwave equipment at the Pirmasens
radio station, Germany. The TCF is housed in several
rooms as shown in figure FO-8. The site is situated in
three major areas; the dc and primary vf patch or test
facility (Room 9), the vf equal level patch and test
facilities (Room 12), and the line conditioning facilities
(Room 8).
a Description of Equipment w No. 1. Row 1 conties as well as the
tains vf and dc patch and
alarm and fuse bays for the
3-1
TM 11-5895-1012-10
tain dc patch panels (low level). Mounted above each dc
patch panel is a Weston 273 low level voltmeter for
monitoring purposes. Each patch bay contains an
interbay panel with lamps and a MISC/INT patch
panel. Bays 1.4 and 1.5 are dc test bays. Bay 1.4 contains an alarm panel, Digital Data Analysis
AN/GGM-11, Express Link Order Wire Unit
TA-923/FSC, and an AN/FGC-80 teletypewriter. Bay
1.5 also contains an alarm panel, an intercom unit,
Digital Data Analysis AN/GGM-15, and a voice orderwire (O/W) unit. Bay 1.5 contains an interbay and a
MISC/INT panel similar to the patch bays.
(2) Primary VF Patch and Test Facilities. Bay
1.15 contains 6-wire primary vf patch panels; bays
1.16, 1.17, and 1.18 contain 2-wire primary vf patch
panels. Bay 1.18 also contains four Hub Data Repeaters. At the bottom of each patch panel is an INT panel
and MISC panel with 10 lamps. Bays 1.13 and 1.14 are
test bays. Each test bay contains an alarm panel, and
INT panel, and a MISC panel with 10 lamps. Test bay
1.14 contains a TTS-26BDR test set, a TTS-27 terminal balance switching set, and a TTS-56RP noise generator. Bay 1.13 also contains Express Link Order
Wire Unit TA-923/FSC, a dc meter panel and Data
ANALYSIS Central DAC-5.
(3) Alarm, Circuit Breaker, Orderwire, and Blank
Bays. Bays 1.19 and 1.20 contain orderwire equipment. Bay 1.21 contains the TCF’s alarm equipment.
This consists of two major/minor alarm panels, two
major alarm panels, and an alarm converter. Bay 1.22
contains dc circuit breaker panels. The top panel in the
bay is the -24VDC breaker panel for supplying the
alarm system. The bottom five panels supply -48
VDC power to the patch and test facilities. Bay 1.23 is
blank for future expansion.
b. Description of Equipment Row No. 2. Row no. 2
contains dc and primary vf patch and test facilities, as
does row no. 1. Bays 2.1 through 218 contain
AN/UGC-61X DC O/W terminals. Bays 2.9 through
2.15 contain dc patch and test facilities, while bays
2.16 through 2.23 contain primary vf patch and test
facilities.
(1) DC Patch and Test Facilities. Bays 2.9, 2.10,
2.13, 2.14, and 2.15 contain dc patch facilities (low
level). Each patch bay has a low level voltmeter mounted above it and has an INT panel, a, MISC panel and a
writing shelf mounted below the jackfields. Bays 2.14
and 2.15 are equipped with cut keys and lamps for use
in conjunction with high frequency radio circuits.
Bays 2.11 and 2.12 are dc test bays. Each test bay contains an alarm panel and a writing shelf. Bay 2.11 contains the voice O/W panel, an INT panel with lamps,
and a MISC/INT panel. Bay 2.12 contains the intercom
unit In addition the two test bays contain the following test equipment, Model PG-303A pattern generator, Teletype Carrier Test Set TCTS-2A, Digital Data
3-2
Analysis AN/GGM-15, and an AN/FGC-80 teletype
writer set.
(2) 4-Wire Primary VF Patch and Test Facilities.
Bays 2.16 through 2.18 and 2.21 through 2.23 contain
4-wire primary vf patch facilities. Each patch bay contains an INT panel and a MISC panel with 10 lamps.
Bays 2.19 and 2.20 are vf test bays. Each test bay contains an alarm panel, and INT panel, a MISC panel
with 10 lamps, and a writing shelf. Bay 2.19 contains a
voice O/W panel and a speaker panel. Mounted above
bay 2.19 is a remote intercom speaker. Bay 2.20 contains a TA-923/FSC orderwire unit and a monitor
speaker panel. In addition the two vf test bays contain
the following teat equipments, TTS-12AR singing
point test set, a TTS-37BR noise measuring set, a
TTS-27R terminal balance switching set, an
AN/USM-181B test set, and a TTS-56R noise generator.
c. Description of Equipment Row No. 1A. Row 1A
contains spare bays, HF radio control bays, and vf
equal level (EL) patch and test facilities.
(1) Radio Control Bays. Bays 1A.3 and 1A.4 each
contain a test bay alarm panel. Bay 1A.3 contains two
SCC recorder announcers and three AN/FTA-28 telephone terminals. Bay 1A.4 contains C-7667/FRR receiver control, a C7669/FRT transmitter control, a
TA-923/FSC order wire unit and a TT-98/FG teletypewriter set. Bays 1A.5, 1A.6, and 1A.7 are used for
HF radio control. The three bays contain Litcom Model
699A and Model 699B receiver and transmitter control units.
(2) Equal Level VF Patch and Test Facilities.
Bays 1A.8, 1A.9, 1A.12, 1A.13, and 1A.14 contain EL
patch facilities. Below the jackfield in each patch bay
is located an INT panel and a MISC panel with 10
lamps and a writing shelf. In addition, bay 1A.10 contains a voice O/W unit, a dual speaker panel. Mounted
above bay 1A.10 is a remote intercom speaker. A
TA-923/FSC order wire unit is mounted in bay 1A.11.
The two vf test bays contain the following test equip
ments, speaker panels, a TTS-37BR noise measuring
set, an AN/USM-181B test set, a 1450-TBR attenuator panel, and a R561B oscilloscope with storage
rack for extra modules.
d. Description of Equipment Row No. 2A. Row 2A
contains vf equal level patch bay and test bay has an
INT panel and a MISC panel with 10 lamps mounted at
the bottom of the bay. There are two sets of test bays
in row 2A, test bays 2A.3, 2A.4 and test bays 2A.10,
2A.11. The left bay in each set of test bays (bays 2A.4
and 2A.11) contains a voice O/W panel and speaker
panel. The right bays in each set (bays 2A.3 and 2A.10)
contain an intercom unit and rack for stowing modules
for the oscilloscope. Bay 2A.3 contains a TA-923/FSC
order wire unit. All four test bays contain alarm panels
and writing shelves. In addition, bays 2A.10 and
TM 11-5895-1012-10
2A.11 contain a TTS-37BR noise
additional monitor speaker panels, a
oscilloscope and an AN/USM-181B test set.
e. Description of the VF CDF Row No. 3. The VF
CDF is constructed of open metal framework. One side
of the frame, known as the horizontal side, contains 10
rows of 56 horizontally oriented terminal blocks. The
other side of the frame, know as the vertical side,
contains 10 rows of 56 blocks oriented vertically. In
columns 22 through 26 of the vertical side, the terminal blocks are replaced by cable protectors for the purpose of terminating outside cable.
f. Description of Equipment Row No. 4. Bay 4.1
through 4.15 and 4.19 are the voice frequency universal conditioning equipment bays. Each bay contains
ten shelves with each shelf capable of containing 12
modules of vf line conditioning equipment. A fuse and
alarm panel is mounted above the shelves with an
intermediate distribution frame (IDF) located at the
top of each bay for the purpose of easy cross-connecting. Bay 4.20 is known as the vf nonuniversal conditioning equipment bay. Mounted in the bay from top
to bottom is a -48VDC containing equipment
breaker panel, two shelves of Stelma 4-Way/4-Wire
bridges, two Stelma SSU-1, signal supply units, a ballast lamp panel, a ring alarm and monitor panel, two
25 Hz ring generators, and six shelves of Northern
Radio type 1030, model 2, 4-Way/4-Wire bridges.
g. Description of Equipment Row No. 5. Row No. 5
contains all the dc condition equipment (DLIU's) necessary for the operation of the site. In addition, the 1000
Hz test tone generators are located in Row 5.
(1) DLIU Bays. Bays 5.1 through 5.9 contain the
digital line interface unit-s (DLIU). Each bay contains
10 shelves, each shelf capable of containing six
DLIU's. A fuse/alarm panel is mounted above the
shelves with an IDF at the top of each bay.
(2) Tone Source Bays. Bays 5.19 and 5.20 contain
the 1000 Hz tune sources for the TCF. A TTS-39A-4
tone generator is mounted at the top of each bay. Each
bay also contains 14 TTS-39D-4 distribution amplifier panels.
h. Description of DC CDF Row No. 6. The DC CDF
is constructed of Open metal framework. The vertically oriented terminal blocks occupy a matrix of 10 rows
of 48 blocks per row. In columns 41, 42, and 43, the
blocks are replaced with cable protectors for the purpose of terminating outside cable.
i. Description of Miscellaneous Equipment.
(1) Supervisor's Console. Located at the head of all
and test facility rows is the supervisor’s conin the console is a voice O/W panel and an
unit. An Order Wire Intercommunications
Section II.
3-4. Function
TCF is a fixed station Technical Con-
Termination Unit TA-930(V)/FSC is on the console.
Behind the console is an AN/FGC-25XDC O/W terminal and test station no 1.
(2) Intermediate Test Stations. The intermediate
test station provides the capability of performing QA
tests from locations remote to the patch and test facilities. Each test bay contains three interbay panels, one
MISC function panel, an intercom speaker panel, and
available rackspace for test equipment. Test station
No. 2 contains a HP-302A wave analyzer.
(3) Mobile Test Bays No. 1, 2, and 3 (not located).
The TCF has three mobile test bays. The bays provide
for the mounting of test equipment. Each
test bay contains a MISC function panel and a writing
shelf. Mobile test bay No. 1 contains a speaker panel,
intercom unit, a Computer Measurements Company
No. 800A, 802A, and 831B an AN/USM-181B test
set, and an envelope delay distortion measuring set
(ACTION LAB INC). Mobile test bay No. 2 contains a
Tektronix R561B and extra module rack, an HP-320
dual channel dc amplifier recorder, and an ACTON
462A transmission delay measuring set. Mobile test
bay No. 3 contains a speaker panel, a TTS-58AR impulse noise counter, an HP-312A frequency selective
voltmeter, an HP-3550 transmission measuring set,
and an envelope delay distortion measuring set
TS-2669/GCM.
(4) AC Power Panels. The ac power panels supply=
ing the TCF are located at the head of rows no. 1 and 2.
The fuse panels on the left supply 220 VAC power to
ceiling lights, wall outlets, and ventilator exhaust
fans. The TCF technical equipment is supplied by the
two tech power panels which are fed via a 100A,
208/120 VAC fuse panel. The non-technical loads are
supplied via the non-technical power panel which is
fed via the 63A, 208/120 VAC fuse panel.
(5) DC Distribution Bays 6.1 through 6.5. The dc
power hays supply +130, ±60, -48, -24, and
±6VDC to the TCF. Bay 6.1 contains the control panel
and two rectifiers used to supply +130VDC. Bay 6.2
contains the two PS alarm panels for the ±60VDC system. Below these panels are two +60 VDC and two
- 60VDC power supplies, ± 60 VDC distribution fuse
panels, a spare fuse panel, ±6VDC fuse panels and the
±6VDC power supplies. Located in bay 6.3 are two
-24VDC Solar power supplies, a Lorain power board
monitor panel (-24VDC) and a -24VDC fuse panel
Located in bay 6.4 are two -48VDC power supplies,
each with a -48VDC meter panel mounted above it.
Bay 6.5 contains all the -48VDC distribution equipment which includes a ground bar, a -48VDC PS
Lorain power board monitor
fuse distribution panels.
BERLIN
trol Facility containing equipment that provides termination, inter-connection, patching, interfacing, condi
3-3
TM 11-5895-1012-10
tioning, monitoring, and testing of voice frequency
and direct current communications circuits and signals.
b. The TCF performs the Defense Communications
System (DCS) Technical Control mission for the supervision and control of the transmission media at the
Berlin Radio Station. This site is a radio nodal point
‘(fig. FO-8) in the European Wideband Communication
System (EWCS) serving a microwave link to Tempelhof (TPF) and a French and British link. A tropospheric link to Bocksburg (BBG) and a satellite link to Landstuhl (LDL). In addition, the site providers cable links
to local vf and dc subscribers.
3-5.
The technical characteristics of the TCF and related
equipment are listed below. Detailed technical characteristics of the individual components that are included in the TCF are listed in the appropriate technical manuals.
a. VF Patching Facilities.
Equal Level Jack Appearances (2 wire) . . .864 ea
Primary Jack Appearances (2 wire) . . . . . . 960 ea
Nominal Signal Leave (E.L. Patch Bays) . . 0 dbm
Nominal Impedance.. . . . . . . . . . . . . . 600 ohms
b. VF Conditioning and Interface Equipment.
Echo Suppressor. . . . . . . . . . . ...:. . . . . . 36 ea
Strappable Pads. . . . . . . . . . . . . . . . . . . . . .72 ea
4W Term Set . . . . . . . . . . . . . . . . . . . . . . . .31 ea
Amplitude Equalizer . . . . . . . . . . . . . . . . . .56 ea
Line Amplifier . . . . . . . . . . . . . . . . . . . . . .218 ea
4 Way - 4W Bridge . . . . . . . . . . . . . . . . . . . .2 ea
6 Way - 4W Bridge . . . . . . . . . . . . . . . . . . . . .2 ea
Envelope Delay Equalizer . . . . . . . . . . . . . .12 ea
C. Signal Conditioning Equipment Quantities.
Test Tone Sources . . . . . . . . . . . . . . . . . . . .20 ea
Ringdown Converter E&M to 25Hz/dc to 25 Hz
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 ea
Pulse Link Repeater. . . . . . . . . . . . . . . . ..100 ea
25 Hz Ringing Supply. . . . . . . . . . . . . . . . . . 1 set
Signal Supply Unit (2600 Hz) . . . . . . . . . . . .2 ea
Signal Supply Unit (1600 Hz) . . . . . . . . . . . .2 ea
Single Freq. Signal Unit-2600 Hz . . . . . .108 ea
Single Freq. Signaling Unit-1600 Hz. . . . . 10 ea
d. Orderwire Capability.
Voice Orderwire Units . . . . . . . . . . . . . . . . . .6 ea
DTMF Access Units . . . . . . . . . . . . . . . . . . . .3 ea
Dc Orderwire Terminals . . . . . . . . . . . . . . . .6 ea
e. DC Patching Facilities.
Dc Low Level Jack Appearances (Full
Duplex) . . . . . . . . . . . . . . . . . . . . . . . . . .120 ea
D C High Level Jack Appearances (Full
Duplex) . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 ea
Dc Lane Conditioning Equipment.
Digital Line Interface Unite (Full Duplex). .95 ea
AC Power Requirements. 108/120 vac, three
3-4
phase, at 50 Hz.
h. Dc Power Supplies.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
+120vdc . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 ea
± 6 0 v d c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ea
±6vdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ea
3-6. Description of the TCF
(Fig. FO-9)
a The TCF is housed in a building connected to the
Berlin Tropo/Microwave Site. Four rooms are within
the building, air conditioning plant room, office, maintenance room, and the technical control room.
b. The technical control room has four bay areas.
(1) Operation area, consisting of rows 1 and 2
along with the supervisor’s console and AN/UGC-54
teletypewriter.
(2) Conditioning and interface area, which is row
3.
(3) Combined Distribution Frame (CDF).
(4) Voice frequency circuit telegraph and power
bays in row 5.
c. The technical control and maintenance rooms are
illuminated by rows of ceiling mounted fluorescent
lamps. Emergency lights (battery powered) are mounted on the right wall as you enter the building. The ac
input power distribution panel along with the technical and non-technical power distribution panels are
mounted on the opposite wall.
d. The floor in the technical control and maintenance rooms raised and consists of a metal frame
supporting tile covered wooden squares. All cabling
and wiring between bays, CDF and ground box are
below the raised floor.
e. A description of the supervisor’s console is as follows:
(1) The supervisor's console is located at the ends
of equipment rows 1 and 2, and in front of the DCA,
reporting orderwire teletypewriter. This allows easy
access to all dc orderwire machines. (One at the end of
each equipment row).
(2) The console consists of two cabinets with a
writing shelf between the cabinets. The left band cabinet contains storage drawers, ac power outlets at the
bottom, and a power monitor panel at the top. The
power monitor panel contains an ac voltmeter, frequency meter, and a dc voltmeter.
Row 1 contains the following equipment:
wire audio patch panels. Bay 1.02 has the No. 1 Universal Transmission Measuring System (UTMS) remote digital display unit at the top. Plus Signaling
TM 11-5895-1012-10
Test Set TTS-26BDR is mounted in the bay below the
display unit. Bay 1.02 also contains six 2-wire audio
patch panels and a speaker panel. Bay 1.04 is the cable
test bay, containing the No. 2 UTMS remote digital
display, a HP-180 AR/TDR
, a HP-4800
vector impedance meter, a speaker panel, and vf orderwire equipment. Bay 1.06 has the No. 3 UTMS remote
digital display at the top. This bay also contains six 2wire audio patch pan&and a speaker panel. Bay 1.07
contains four 2-wire audio patch panels and a
SB-1642 top resistance panel. The portion above the
writing shelf of bay 1.08 is blank for future use as required. There is a SB-1642 loop resistance panel below
the writing shelf.
(2) High Level DC Patch Bays 1.09 and 1.10. Each
of these bays contain a 48 lamp interbay panel, MISC
panel, writing shelf, a loop resistance panel, and have
ac power outlets at the bottom. Bay 1.09 also contains
a dc meter panel and four dc patch panels. In addition
Bay 1.10 contains a digital multimeter, two dc patch
panels and Telegraph Test Set AN/GGM-15(V).
(3) Fuse and Alarm Bay 1.11 and Orderwire Bay
1.12. Ray contains two major/minor alarm panels, a
major alarm panel, three SB-1523/FT fuse panels,
three loop resistance panels, and ac outlets at the bottom of the bay. Bay 1.12 is an AN/UGC-61X dc orderwire teletypewriter set.
g. Row 2 contains the following equipment:
(1) Equal Level Patch Bays 2.01 Through 2.06.
Each equal level patch bay contains space for eight 2wire audio patch panels, INT panel, MISC panel, writing shelf, and a dual ac power outlet. Bays 2.02 and
2.06 have only six audio patch panels installed. Bay
2.04 is blank above and below the INT panel, MISC
panel, and writing shelf. Bays 2.02 and 2.05 each have
a remote digital display at the top of the bay and a
dual speaker panel below the writing shelves.
(2) Quality Assurance Bays 2.07, 2.08 and 2.09.
These three bays each contain an INT panel, MISC
panel, writing shelf, and dual ac power outlets. A baseband monitor panel and two echo suppressor control
panels are mounted near the center of bay 2.07. The
TTI-1140 Universal Transmission Measuring System
(UTMS) master unit and power supply, along with the
No. 7 remote digital display are mounted in bay 2.08.
The UTMS associated relay panel, and a dual speaker
panel are in the bottom of bay 2.09. The remaining
space in the bays is provided for mounting test
equipment. The test equipment may be rearranged or
replaced as required by test requirements or change in
the state of the art.
(3) Low Level DC Patch Bays 2.10 and 2.11. Each
patch bay has a low level voltmeter mounted above it
and has a 48 lamp INT panel, a MISC panel and writing shelf mounted below the jackfields. Bay 2.10 contains five transmit patch panels and bay 2.11 contains
five receive patch panels.
(4) Low Level Test Bay 2.12 and DC Orderwire
Bay 2.13. Test bay 2.12 is shown with a digital
multimeter and AN/GGM-15(V) Telegraph Test Set
installed. (These equipments may be changed as required). Below the test equipment area there is a 48
lamp INT panel, MISC panel, and a writing shelf. The
low level ±6 volt power supplies, fuse panels and
alarm panel are in the bay below the writing shelf. Bay
2.13 is an AN/UGC-61X dc orderwire teletypewriter
set.
h. Row 3 contains the following equipment:
(1) Universal conditioning Equipment Bays. All
the bays in row 3 except bay 3.04, 3.08 and 3.09 are
universal conditioning equipment bays. Intermediate
distribution frames (IDF) are mounted at the top of
these bays. Below the IDF's are fuse-alarm panels.
Each bay contains ten universal conditioning equip
ment shelves, each shelf containing 12 module slots.
Conditioning equipment modules are inserted into the
shelves as required to build circuits through the technical control facility.
(2) DLIU Bays. Bays 3.08 and 3.09 contain the
digital line interface units (DLIU). Each bay contains
10 shelves, each shelf capable of containing six
DLIU’s. A fuse/alarm panel is mounted above the
shelves with an IDF at the top of each bay.
(3) Non-Universal Bay 3.04. At the top of the bay
there is a UTMS remote digital display, a MISC panel
and a 4-way-4-wire bridge shelf. A 25 Hz ringing sup
ply system consisting of ballast lamp panel, 20 Hz
alarm and monitor panel, and two 25 Hz ring generators are mounted in the center of the bay. At the bottom of the bay there is a station reference tone source
(TTS-39A) and four distribution amplifier panels
(TTS-39D).
i. The combined distribution frame (CDF) in row 4
is constructed of open metal framework. One side of
the frame, known as the horizontal side, contains 30
rows of 10 horizontal terminal blocks. The other side
of the frame, known as the vertical side, contains 31
columns of 9 vertical blocks per column. The first
seven columns contain 750 four wire, line protector
blocks.
j. Row 5 contains the following equipment:
(1) Mobile Test Buy 5.01. This bay is mounted on
dolly type wheels to allow it to be moved throughout
the TCF as required. The bay contains a INT/MISC
panel, a storage drawer, and an ac power connector.
The mobile bay provides rack space for the mounting
of such test equipment as a digital multimeter, transmission measuring set, envelope delay test set and X-Y
recorder.
(2) Voice Frequency Carrier Telegraph Bays 5.02
Through 5.05. Each of the four voice frequency carrier
telegraph (VFCT) bays is a Telegraph Terminal
3-5
TM 11-5895-1012-10
(3) Mux. Bay 5.06 and Power Equipment Bays
5.07 and 5.08. Bay 5.06 is a Collins MTX-201, VFCT.
Bay 5.07 is the -48 vdc power source bay. There are
two -48 power supplies at the bottom of the bay. Fuse
distribution panels along with a Lorain power hoard
monitor panel are above the power supplies. Bay 5.08
houses the ±60 vdc and 120 vdc power equipment
along with a modified SB-1642 loop resistance panel.
A Hub repeater is also mounted in the bay. Two dc
voltmeter panels, three fuse panels and an alarm panel
are at the top of the bay. Four Northern Radio Model
370-1 power supplies are below the Hub repeater. Two
power supplies strapped for + and - 60 vdc outputs.
(4) Orderwire Equipment Bay 5.09. The DualTone Multiple Frequency (DTMF) orderwire equip
meat bay contains an SD-3751/FSC fuse panel, Remote Link orderwire Unit TA-924/FSC, one line card
shelf, and two common equipment shelves. Duplex ac
power outlets are in the front and rear bottom of the
bay. IDF blocks, inductors, and a component board are
in the rear of the bay.
Section III. PENTAGON
3-7. Function
a. Pentagon Telecommunications Center (fig.
FO-10). The U.S. Army Communications Command
Telecommunications Center (PTC)
mmunications Systems (DCS) for
b. Technical Control Facility (fig. FO-11). The
cal Control Facility (TCF) at the Pentatechnical control over BED and BLACKITAL, and VIDEO circuits appearing at
se are comprised of military-owned VFCT
s and leased DC and data circuits. The high
data circuits are in the 2400 to 50K BAUD
The low speed circuits are predominantly
secure circuits. Test and maintenance is also provided
on Government-owned lines and circuits.
c. Patch and Test Facility. (fig. FO-12). The P & T
function includes the monitoring of circuits and equip.
ment within a station, as well as the selection and
application of the station facilities and associated
equipment, as n
to keep the station’s operating
and standby communications links and circuits at peak
. The Technical Controller coordinates
in communications services at the station,
alternate routings, directs the correction of
functions, restores service when outages occur,
and coordinates link and station tests. The P & T Facile station encompasses these areas which
with jacks, and test instruments to provide access to the circuits for the purpose of performmonitor, patch and test operations.
To efficiently perform the technical control func3-6
tions required to keep all communication links at their
peak operating condition, all personnel must be thoroughly familiar with the station capabilities and the
functions of all equipment in the station. In addition,
familiarization with circuit links of related technical
control is required.
e. The Pentagon technical control facility is the
main Army TCF serving the Washington D.C. area.
The facility provides many high priority circuits to
and from various local government users to locations
scattered throughout the free world and to the Kremlin. Users and connecting sites often change.
f. The patch and test facilities of the TCF provide
access to each circuit for monitoring, rerouting, and
testing. Access is provided to both the black (encrypted) and the red (clear) sides of the circuits.
3-8. Technical Characteristics
a. VF Patching Facilities:
Red VF Jack Appearances (2-wire). . . . . .264 ea
Black VF Jack Appearances (2-wire) . . . .960 ea
Nominal Test Tone Signal Leval . . . . . . -2 dbm
Nominal Circuit Impedance . . . . . . . .600 ohms
Normal Send Signal Leval . . . . . . . . . . . +8 dbm
Normal Receive Signal Leval . . . . . . . . -13 dbm
b. DC Patching Facilities:
Red DC Jack Sets.. . . . . . . . . . . . . . . . . .912 ea
Black DC Jack Sets . . . . . . . . . . . . . . . . 1,296 ea
Nominal Signal Level . . . . . . . . . . . . . . . ±6 vdc
C. Video Patching Facilities
Red Video Jack Appearances.. . . . . . . . .160 ea
Black Video Jack Appearances . . . . . . . . 100 ea
Nominal Circuit Impedance . . . . . . . . .75 ohms
d. AC Power Requirements . . . . . . . . . . . . . . . . . . .
208/120 vac, 3 phase, 60 HZ.
e. DC Power Supplies
6 VDC . . . . . . . . . . . . . . . . . 4 ea: 2 Red, 2 Black
24 VDC. . . . . . . . . . . . . . . . . 4 ea: 2 Red, 2 Black
48 VDC . . . . . . . . . . . . . . . . 4 ea: 2 Red, 2 Black
3-9. Description of the TCF
The equipment is housed in two different rooms. All of
TM 11-5895-1012-10
the facilities (except the quality assurance (QA) equipment) are located in TCF, room 5A910 (fig. FO-12).
There are three bays of QA equipment in the Electronic Maintenance Room (para 3-10). As shown in figure
FO-12, the TCF consists of two rows of equipment
bays, a red cable vault, and red and black ground and
power distribution boxes. In addition the room contains Crypto equipment, modems, voice frequency carrier telegraph (VFCT) equipment and etc. Equipment
rows No. 1 and No. 2 are described in paragraphs a and
b below. Sample bay elevations are shown in figures
3-1, 3-2, and 3-3.
a. Description of Equipment Row No. 1
(1) General. Equipment row No. 1 contains 21
bays of patch and test equipment and four bays of
DCL/MOLINK equipment. Bays 1.22 through 1.24
(DCL/MOLINK) are covered in (C) PDEP
11-5895-832-14(2). Row No. 1 is called the black
equipment row, because bays 1.1 through 1.21 connect
to unsecure or encrypted circuits.
(2) Black VF and Digital IDF Bays. Bay 1.1 con&b of two intermediate distribution frame (IDF)
bays. Bay 1.10 consists of three IDF bays. Each bay
contains a front door to allow access to a patch cord
type cross connect matrix. The IDF's are similar and
discussed in paragraph 3-11.
(3) Black VF Patch Bays. Bays 1.2, 1.3, 1.4, 1.6
and 1.7 are the VF patch bays. Each of these bays contains eight 2-wire audio patch panels and an interbay
(INT) patch panel. Bay 2.1 has a R-390 radio receiver
in the bay below the patch panels. Bays 1.3 and 1.7
each have a 60 station voice order wire panel, that are
furnished and maintained by the telephone company.
Bays 1.4 and 1.6 have dual speaker panels and
AM-911/FG audio frequency amplifiers mounted
below the patch panels.
(4) Black VF Test Bay 1.5. This bay contains various test equipment. There is a writing shelf with a miscellaneous (MISC) and INT panel above the shelf. In
addition there are two test equipment connection
panels. Test equipment without rear test lead connectors are connected to the MISC panel through the
test equipment connection panels.
(5) Video Monitor and Station Clock Bays 1.8 and
1.9. Bay 1.8 has two video monitors at the top, used to
monitor the TCF door and outside hall. A panel with a
push-button switch for unlocking the door is below the
monitors. There are five TWINAX wide band patch
panels in the bay. The remainder of the bay is used to
mount test equipment. Bay 1.9 is a TDS-2 Station
Clock Bay.
(6) Black Digital Patch Bays. Bays 1.11, 1.12,
1.13, 1.15, 1.16, 1.17, 1.19, 1.20 and 1.21 are the
black digital patch bays. Each bay has a ± 15 vdc
meter mounted in the panel at the top. There are six
universal dc patch panels and a INT panel with 48
lamps in each bay. The bottom of bay 1.11 mounts the
black -48 vdc power system; consisting of two 48 vdc
power supplies, an alarm panel, and a fused power distribution panel. Bays 1.12 and 1.19 each contain an
order-wire panel. Bays 1.13 and 1.15 have writing
shelves with AN/FGG-80 t&typewriter sets mounted
on the shelves. One 24 vdc power supply is in bay 1.16
with a second unit in bay 1.17. Bay 1.16 contains the
24 vdc meter panel, alarm panel and fused power distribution panel. Bay 1.17 also contains the black 6 vdc
power system; consisting of two power supplies (with
alarms), meter panel, and fused power distribution
panel. Bay 1.21 includes the black indicating equip
ment; consisting of a MAJOR/MINOR alarm panel,
audible alarm panel and two crypto ancillary unit/cornmon control unit (CAU/CCU) alarm panels.
(7) Black Digital Test Bays. Bays 1.14 and 1.18
are the black digital test bays. The bays are similar in
configuration. Each bay contains a ± 150 vdc meter
panel, a 601 Data Transmission Test Set, HP-180BR
Oscilloscope with connection panel, AN/GGM-15(V)
Telegraph Test Set, INT panel with 48 lamps, and a
writing shelf.
b. Description of Equipment Row No. 2
(1) General. Equipment row No. 2 contains 20
bays of equipment and four bays of IDF patch cord
cross connect matrixes. The four IDF bays are all
numbered 2.21. Row No. 2 is called the red equipment
row, because the circuits may carry secure information
in clear test. Bays 2.1 through 2.20 are described in (2)
through (6) below.
(2) Special Intelligence Bay 2.1. SI bay 2.1 is
isolated from the rest of the TCF. The bay contains a
color video monitor at the top with eight video
distribution amplifiers, and three 75 ohm patch
panels. Between the monitor and amplifiers there are
two universal dc patch panels (digital patch panels)
and three 2-wire audio patch panels (VF patch panels).
The bay also has its own IDF consisting of two rows of
patch cord cross connect matrixes.
(3) Red Digital Patch Bays (fig. 3-1). The red
digital patch bays are bay 2.3 through 2.6, 2.8 through
2.11 and 2.13 through 2.16. Each of these bays has a
± 15 vdc meter mounted in a panel at the top of the
bay. Below the meter panel there are six digital patch
panels and a INT panel with 48 lamps. Bays 2.11, 2.13
and 2.14 each contain a writing shelf used to mount
AN/FGC-80 teletypewriter sets. Each bay has blank
panels below the patch panel. The blank panels may be
removed to allow installation of equipment as required.
(4) Red Digital Test Bays (fig. 3-2). Bays 2.2, 2.7
and 2.12 are the red digital test bays. Each of these
test bays is used to mount test and monitor equipment.
In addition there is an INT panel with 48 lamps and a
writing shelf in each bay.
3-7
TM 11-5895-1012-10
(5) Red Power and Video Monitor Bays. Bay 2.17
mounts six dc power supplies (two 48 volt, two 24 volt
and two 6 volt), along with associated fused distribution panels and alarm panels. The 6 vdc and 24 vdc
supplies do not contain current and volt meters. There
Figure 3-1. Red digital patch bay (typical), front view.
3-8
fore, a meter panel is provided to measure the output
of these supplies. At the top of this bay there is a
MAJOR/MINOR alarm panel along with an associated
audible alarm panel. Video monitor bay 2.18 has a
Figure 3-2. Red digital test bay (typical), front view.
TM 11-5895-1012-10
3-10. Description of Quality Assurance
Test Center
(fig. 3-4)
The QA test center consists of three bays located in the
Electronic maintenance room. The bays contain test
equipment and panels as shown in figure 3-4. The test
center is connected to red circuits in the TCF through
the RED REIAX 75 ohm INT TRUNK in bay 2. Black
TCF circuits are connected to the QA test center
through the black INT panel in bay 1.3.
3-11. Intermediate Distribution
a. General. There are four IDF's in the TCF area
They are an integral part of the Technical Control Facility and each equipment signaling input and output
connections are terminated at an IDF. In addition, the
input and output signals of each patch panel and circuit line are also terminated at an IDF. (Wide hand circuits are not connected through IDF's).
b. Description. Each IDF consists of a matrix made
up of rows of cross-connect panels. A panel contains
ten jack type patch modules (A through H, and J, and
K). Each module has six multi-colored rows of 26 jacks.
The color of the jack rows at the front of the modules,
from left to right are: red (A), white (B), blue (C), yellow (D), black (E), and orange (F). Each of the 156 jacks
is connected to a pin on one of three associated connectors mounted on the rear of the panel. The first 48
jacks on the module are connected to pins 1 through 48
on connector J1. Module jacks 40 through 96 are connected to pine 1 through 48 on connector J2. Module
jacks 97 through 144 are connected to pins 1 through
48 on connector J3. Module jacks 145 through 156 are
also connected to connector J1, J2 and J3. Four jacks
to each connector. The connectors are cabled to patch
3-12. Digital Circuits, General
Figure 3-3. Red vf test bay (typical), front view.
TCF provides cross-connection. monitoring, testing,
circuit patching access, and timing clock for black and
red digital circuits. A typical black circuit is discussed
in paragraph 3-13. All digital circuits are connected
through a Universal Digital Patch Panel. The patch
panel and its different configurations are discussed in
paragraphs 3-14 and 3-15.
3-9
TM 11-5895-1012-10
EL3Z0084
Figure 3-4. Quality assurance test center
3-10
TM 11-5895-1012-10
3-13. Typical
Digital Circuit
(fig. FO-13)
a. General. In this example of a black digital circuit,
the Universal Digital Patch Panel jack sets are programmed with a group 4 module in the send circuit
and a group 5 module in the receive circuit. Refer to
paragraph 3-156 and c for patch panel circuit details.
This circuit is cross-connected in IDF bay 1.10. The local equipment (EQUIP side of circuit) is cabled to module A of panel 6. The line equipment (LINE side of circuit) is cabled to module A of panel 1. The jack sets of
the Universal Digital Patch Panel are cabled to module
A of panel 2. Optional devices are not used, but connections that could be used are shown.
b. Send Circuit. To complete the send circuit, dualplug, cross-connect patch cords are installed as follows:
(1) Patch cord No. 4, from jacks 1 and 2, module
A, panel 6 to jacks 1 and 2, row 2, module A, panel 2.
This connects the transmit data output of the user
equipment to pin 5 of patch panel connector C-l. This
is the jack sets tip (T1) lead, which is normal-through
wired to pin 1 (tipT) of patch panel connector C-l. Pin
1 of C-1 is cabled to jack 1 of row 1 in module A, panel
2. The transmit data return is also cross-connected
with patch cord No. 4, and is connected to a common
tie point.
(2) Patch cord No. 1, between jacks 1 and 2, row 1,
module A, panel 2 and pins 1 and 2, row 1, module A,
panel 1 completea the transmit data and transmit data
return to the line equipment.
(3) Patch cord No. 5, from jacks 3 and 4, row 1,
module A, panel 6 to jacks 3 and 4, row 2, module A,
panel 2 connects the transmit clock through the R1
and R leads of the patch panel jack set, to jacks 3 and
4. row 1. module A. panel 2 of the IDF. The transmit
clock return is also connected to the common tie point
through patch cord No. 5.
(4) Patch cord No. 2, from jacks 3 and 4, row 1,
module A, panel 2 to jacks 3 and 4, row 1, module A,
panel 1 completes the transmit clock and transmit
clock return to the line equipment.
c. Receive Circuit. To complete the receive circuit,
dual cross-connect patch cords are installed as follows:
(1) Patch cord No. 7, from jacks 1 and 2, row 2,
module A, panel 1 to jacks 1 and 2, row 3, module A,
panel 2 connects the receive data line to the tip (T) lead
set. The T lead is nor1 lead of the patch panrow 4, module A, panel
rd connects the receive
patch panel jack set to the receive pair of the user
equipment.
(3) Patch cord No. 8, from jacks 3 and 4, row 2,
module A, panel 1 to jacks 3 and 4, row 3, module A,
panel 2 connects the receive clock to the ring (R) lead
of the patch panel jack set. The R lead is normalthrough wired to the R1 lead of the jack set and cabled
to jack 3, row 4, module A, panel 2 of the IDF. The
same patch cord also connects the receive clock return
to a common tie point and to jack 4, row 4, module A,
panel 2 of the IDF.
(4) Patch curd No. 11, from jacks 3 and 4, row 4,
module A, panel 2 to jacks 3 and 4, row 2, module A,
panel 6 completes the receive clock circuit to the local
equipment.
d. Red Digital Circuit. A red digital circuit is connected in a similar manner and will not be discussed.
3 - 1 4 . Universal Digital
a. Description. The front
tains 24 sets of four jacks with a switch and lamp that
is associated with each jack set. There are three rows
of identification (ID) card holders. The card holders allow the circuit and equipment connected to the circuit
to easily be identified. The rear of each patch panel has
two connectors (Cl and C2), that are used to connect
the jack set circuits (through connectors J1 and J2) to
the IDF. Below the connectors are 24 program modules. Between the connectors and program boards
there is a jack set ID strip indicating the jack set associated with each program board.
b. Circuit Functions (fig. FO-15). Each jack set is
connected (through a flexible printed circuit board) to
a program board. The board is programmed by a program module (containing jumpers) to set up an operational circuit. The functions that may be performed by
the circuits are given in (1) through (6) below. Two typical circuits for which modules are available are discussed in paragraph 3-15.
(1) Provides a normal through path for digital signals when no patches are made.
(2) When patching in a replacement sending device, the patching configuration will terminate the interrupted sending equipment in an impedance equal to
the input impedance of the receiving device.
(3) When patching in a replacement receiving device the patching configuration will hold the interrupt
ed receiving equipment with a holding voltage or current equal to the mark voltage or current transmitted
by the sending device.
(4) The patch panel will perform the above functions for all the following types of digital signals:
(a) Low level ± 6VDC send and receive.
(b) Low level ± 3VDC send and receive.
(c) High level polar or neutral send and receive.
(d) Low level receive with associated timing.
3-11
TM 11-5895-1012-10
send with timing from an external
standard to both sending and receiving devices.
(5) The patch panel also incorporates a special
circuits utilizing either an external
function for
timing standard or timing from a receiving device to a
sending device. When a transmitted signal is to be
receiving portion of the same
patched back
purposes, a problem would norequipment for
mally arise. Since external timing is necessarily introduced on the line side of a jack field, a line-send-to-linel (back to back) patch required to perform
ve test for equipment external to the TCF contwo timing signals (one injected into the send
field and one received on the incoming line). Conversely, an equipment send-to-equipment-receive (back
to back equip) patch required to perform the test for
equipment internal to the TCF contains no timing signal. When timing is sent from a receiving device to a
the same problem can occur (i.e., two
on a back to hack line and none on a
uip).
A push button "back-to-back” switch allows the removal of one of the two timing signals present in a back to
line patch and the introduction of timing in a
to-back equip patch. An indicator light as well as
switch position indicates the activation of this function in all cases.
(6) The signal common “ring” lead of an interrupted signal is never left open. It may be supplied DC
ground or another program elected termination.
3-15. Universal Digital Patch Panel,
Programs
3-12
M3 to M2
D3 to E2
M3 to J3
H3 to E1
L1 to J1
F2 to F3
H3 to N3 (Not shown)
Al to H1 (Not shown)
A2 to M1 (Not shown
E3 to K1 (Not shown)
H3 to N3 (Not shown)
C3 to D1 (Not shown)
C3 to K3 (Not shown)
(2) When a patch cord plug is inserted into the
LINE jack, the following connections are made.
Terminal
T
T1
R1
External timing
(3) When a patch cord plug is inserted into the
EQUIP jack, the following connections are made.
Terminal
T
R
External timing
T1
To plugged line equipment
R1
To plugged line equipment
c. Black Receive Circuit, Program Module GP-5
(fig. FO-16).
(1) This programming module connects the following terminals:
B2 to E1
B1 to J3
C1 to F3
B3 to J1
C2 to N2
D2 to K3
TM 11-5895-1012-10
Termination
To TCF
equipment
To TCF
equipment
Unterminated
Unterminated
Terminal
T
R
T1
R1
Termination
Unterminated
Unterminated
From pl
line equipment
From pl
line equipment
3-13
TM 11-5895-1012-10
CHAPTER 4
TECHNICAL CONTROL FACILITIES OPERATIONS
Section I. OPERATION PRACTICES AND METHODS
4-1. System Management
sions. Examples of its specific station operational
functions are:
(1) In the case of the Berlin TCF, to provide a
relay service to Templehof (TPF) and be the central
access point to the Defense Communications System
for subscribers in the local area.
(2) In the case of Pirmasens, to provide wideband
relay service to Zweibruken (ZBN), Langerkopf (LKF),
and Donnersberg (DON) as well as being the central
access point to the DCS.
b. The mission of a TCF encompassed all of these
actions necessary to maintain flexibility in traffic and
circuit routing, reliability of through and terminating
circuits, and peak efficiency in transmission quality.
This capability can be realized only by employing approved management principles and by strict adherence
to proven standard operating procedures at all stations.
c. Overall system management direction resides
with the Defense Communications Agency (DCA) and
the Army Communications Command (ACC). Specific
designed as the station control center and is equipped
to permit effective station management. All operational orders, circuit activation and deactivation functions, system reporting, alternate routing procedures,
formed by the Technical Control operators. Much of
the content of this chapter is therefore addressed
specifically to the station Technical Controllers and is
intended to be used as a working guide in conjunction
with station SOP's, records, and individual equipment
manuals and handbooks. Since the circuit configuration is subject to operational changes a detailed study
of the equipment description of those items on site
should be made to ensure familiarity with the facilities
provided. Moat of the day-to-day Technical Control operations require a thorough understanding of the complete station facility and
the Technical Controller
ing knowledge of the
4-3. Station Management Facilities and
Usage
4-2. Station Management Approach.
(1) High Frequency Interface. The multiplexed
4-1
TM
11-5895-1012-10
the TCF. Rerouting of the multiplexed groups is readily accomplished at this central point by patching.
(2) Voice Frequency Channel Interface. The multiplex channel modems are wired to the Equal Level
Patch bays in the VF Technical Control area. The
patching facilities in this area provide access to the circuits.
(3) DC Circuit Interface. In the TCF DC area,
patching access is provided to DC subscriber loops and
VFCT circuits by the DC patch facilities.
b. Monitoring and Testing Functions.
(1) Monitor and Test Point Interface. All VF and
DC jacksets include a monitor jack appearance. These
jacks are arranged to permit monitoring and testing
without interrupting the circuit.
(2) Teat Bay Interface. The test bays contain
transmission measuring equipment and other test
item to facilitate maintenance, fault isolation, analysis, and correction.
c. Status Reporting and Coordination Functions.
Operating personnel at the station are the primary
users of the supervisory Subsystem which provides
orderwire communications. This subsystem provides
communications with other stations as required. Reporting requirements are established by the station
SOP.
4-4. Duties
4-5. Orderwire
Effective control of that
comes under the responsi
Facility requires format
r
a. General. The principal functions of the Technical
controller are to moni
d patch, as required,
4-6. Orderwire Procedures
4-2
TM 11-5895-1012-10
location. Technical control notices will contain a full
heduled TELECON’s with the details
arrangements with adecircuit, conduct tests and
request is received without
advance notice, the contacted TCF will provide the
service as rapidly as possible.
d. If the user reports trouble, immediate action will
be taken to clear the trouble or provide an alternate
circuit within normal restoration priorities.
e. When notified by the user that the TELECON is
finished, the controller will initiate action to break
down the special arrangements used and return the
circuit to normal use.
4-9. On-Call Patches
4-7. Orderwire Circuit Discipline
4-8. TELECON Circuits
On-call patches is in no way intended to substitute for
planning to meet known communications requirements. They will be activated for a period not to
exceed 72 hours. If the requirement is to exceed 72
hours, the requesting activity will be advised to submit
an emergency minor telecommunications requirement.
When a request for an on-call patch is received the following action will be taken by the technical controller
a. Determine and establish the route to be employed
and the equipment required to provide satisfactory
service.
b. When the on-call patch cannot be established,
contact the appropriate DOCC for assistance in
accordance with established procedures.
c. Report all on-call patches in accordance with
established procedures.
d. Construct a temporary CCSD in accordance with
established procedures.
e. Deactivate the on-call patch when notified by the
user that it is no longer required. The technical controller will coordinate with the next TCF through
which the circuit is patched to effect deactivation. All
TFC's will follow the same procedure until the circuit
is restored to normal. When the user will not release
an on-cdl patch after 72 hours and an emergency telecommunication request has not been received, the
appropriate DOCC will be notified for permission to
break down the circuit.
4-10. Scheduled Service Interruptions
Policy requires that the best possible communications
service be provided to users of the DCS commensurate
with available equipment and facilities. To provide
this service it may be necessary, at times, to remove
equipment from service or, in cases of major engineering changes, require the complete shutdown of a communications facility. These outages, which will be held
4-3
TM 11-5895-1012-10
to a minimum, are known in advance and every effort
must be made to provide continuing service during the
time a facility is out of service. When it is absolutely
necessary to remove communications equipment, facilities, or an entire DCS Station from service, the planning, notification, and restoral of service must be
thorough and complete.
a. Planning. Service interruption will normally be
scheduled when minimum communications impact
will occur and will provide, where possible, for uninterrupted service to users. Planned actions will be
time-phased to allow control to be maintained at all
time, to ensure that communications capabilities will
not be exceeded and to ensure the communications are
successfully completed. Planning will include recovery
should an emergency arise which would prevent the
completion of planned actions. In addition, the planning will consider leasing of additional circuits from
commercial carriers, as necessary, to provide uninterrupted service.
b. Notification. It is of utmost importance that all
users of the DCS be informed of any action that will or
may tend to degrade their service.
c. Supervision. Control and implementation of a
scheduled service interruption rests with the TCF.
Supervising DOCC elements will ensure that dependable communications are maintained to the element
implementing the outage.
d. No User Service Interruption.
(1) When there will be no interruption of user
service and sufficient spare or backup equipment is
available during the affected period, no additional responsibilities, other than normal control practices, are
required.
(2) When there will be no interruption of user
service and sufficient spare or backup equipment is
not available during the affected period, the DCS station will notify the appropriate DOCC and operation
and maintenance element of this hazardous condition.
If necessary, the DOCC element may cancel or request
rescheduling of this type of interruption. Further, it
may be required that the users be notified of the existing hazardous condition.
e. Interruption of User Service. For service inte
ruption, other than a complete DCS Station, prior
ordination and approval is not required on
releases of single circuits or single channel
concurrence has been obtained from
terminals. However, if the interrup
magnitude, but less than the comple
nation and approval must be accomp
tained in accordance with existing regula
directives. Where the complete DCS Stat
volved coordination and approval is
ance with existing regulations and directives even
though user concurrence has been obtained.
4-11. Emergency Interruption of Service
prior coordination. However, as soon as possible, the
circumstances involved will be reported to the various
elements in accordance with existing regulations and
directives.
4-12. Interruption of Service to Correct
Hazardous Conditions
cation is waived for complete station interruption of
short duration to correct hazardous conditions providing all the following conditions are satisfied:
a The station is in a hazardous condition and the
condition has been reported in accordance with existing regulations and directives.
b. All necessary equipment and the technical ex
tise is available on-site to correct the hazardous co
tion.
c. User concurrence for the outage has been obtained.
d. The interruption is scheduled for non-busy hours.
e. Reroute or restoral actions will not be required
f. Appropriate DOCC elements have been contac
and advised that the above requirements have been
met prior to the time of interruption occurs.
Section II. CIRCUIT REROUTING
4-13. Introduction
4-14. Normal Circuit Rerouting
Circuit rerouting is normally accomplished on a
planned (scheduled) basis on orders from DCA or ACC.
System planning and growth, circuit priorities, link or
equipments reliability, subscriber population density,
party line or command net configurations, and system
maintenance may be major system operating factors
which generate circuit rerouting requirements. In addition, system or equipment failures may necessitate
emergency circuit rerouting.
All normal circuit rerouting requirements are determined by ACC or higher authority and are primarily
based on satisfying customer demands or improving
communication services in a particular area of the systern. In the latter case
ment is the result of
operating and service
taken from the daily technical control and maintenance logs and reports which are submitted by all
4-4
TM 11-5895-1012-10
ACC and/or higher headquarters.
prior to getting the circuits back into service. Any nonpatching type rerouting actions required to restore
service to less than highest priority critical circuits
must be first coordinated with or have the approval of
DCA or ACC.
4-16. Catastrophic Failure
pleted, and the circuit verified in service, the station
records are updated and details promptly forwarded to
ACC in order that the system master files and records
can be maintains current at all times.
Circuit
4-15.
Any circuit rerouting necessitated by system, equip
ment, or facilities failure can be identified as an emergency requirement. Emergency circuit rerouting is accomplished in so far as possible, by temporary cord,
plug and jack patching arrangement? at or through the
Technical Control Facility using installed spare equip
ments or channels to bypass the failed equipment or
portion of the circuit or system. The magnitude of failure will determine the degree of emergency attached
to each service interruption. A majority of the service
troubles encountered can be attributed to failure of a
minor item of in-station equipment; in this case, the
station personnel are able to restore service expeditiously by patching in spare equipment or components.
As soon as maintenance personnel repair or replace the
failed items, the circuit is restored to its normal path.
All troubles must be logged and reported, but the use
of installed spares need not be coordinated with ACC
The failure of link equipment, transmitters, or multichannel equipment involving critical highest priority
circuits, either by error or intent of man, or by natural
forces, are considered catastrophic failures. Under
these conditions, the restoration of service to critical
and high priority circuits is of paramount importance.
Of equal importance at this time is the need to notify
ACC of the failure event, the point of failure, extent of
damage, estimate of work, equipment, and time involved in correcting the failure, and what has been
done or is being done to restore service. Station supervisors and station Technical Controllers immediately
take action to reroute predetermined critical and high
priority circuits to the maximum degree possible over
available spares whenever alternate routing links are
available. As services are restored, DCA and ACC are
notified. DCA or ACC evaluates initial reports and all
subsequent status reports and initiates necessary instructions to Station Supervisors and Technical Controllers detailing additional circuits to be rerouted and
routes to be used. DCA or ACC also indicates which, if
any, lesser priority circuits will be preempted in order
to maintain a maximum service balance throughout
the entire system until the failures can be completely
restored to normal service.
Section III. PATCHING OPERATIONS
4-17. Pu
of Patching
Patching is defined as the rearrangement of the electrical interconnections among items of station equip
ment by means of pat&cords and jackfields.
a. Service Restoration. The various patching facilities provided in the station Technical Control area enable the Technical Controller to take positive action to
restore service when a circuit failure has been localized
to a station. Such restoration action consists of bypassing the defective equipment and substituting like
equipment from the complement of operational spares
and, similarly, substituting spare, or lower priority,
channels for those degraded or inoperative. The substitution of equipment usually involves only a local
patching operation, while substitution of channels requires a coordinated patching operation at the distant
terminal.
b. Fault Isolation by Substitution. Substitution of
station equipment and channels by patching operaa valuable fault isolation technique. A logical
re of successive substitutions of equipment
and/or channels usually locates the trouble. Often, it is
possible to patch out all station equipment in one
patching operation, establishing quickly whether the
fault is in any of the local station’s equipment. Once a
channel or equipment has been patched out, test equip
ment is employed to evaluate circuit performance and
to localize the trouble.
c. Service Continuity During Maintenance. Preventive maintenance routines require periodic quality
control tests (Section VI) and adjustments of channels
and station equipment. When it is necessary to conduct such tests on assigned channels or equipment,,
service is maintained by a patching substitution. Fault
isolation (Section IV) requires that the defective equip
ment is disconnected from the circuit and a spare sub
stituted. This substitution is accomplished by patching.
d. Operational Spares. Operational spares facilities
consist of spare multiplex and VFCT channels and
selected items of equipment cross-connected into
specific spare configurations. Whenever such spare
4-5
TM 11-5895-1012-10
equipment is available, spare circuits, which correspond to the DCS options in use at the station, may be
established to permit rapid restoration of circuits by
in-station patching.
4-18. Patching Precautions
a. Temporary Measure. The use of patchcords to set
up or rearrange circuits is intended as a strictly temporary measure. Service restoration patches should be
taken down as soon as the fault condition has been
cleared. In some cases, circuit orders may be issued
which specify that patchcords be used to set up or rearrange a circuit to fill an emergency or temporary requirement. Such orders may specify, for instance, that
circuits be established without delay by patching, and
later by cross-connected at the frame to make a permanent configuration. The patch is to be taken down
as soon as the normal circuit is arranged. The operational objective is to keep the jackfields as free of
patchcords as possible. A multiplicity of patches in a
jackfield frequently results in confusion as to the purpose and authority of the patches, and whether they
are still required. To preclude such confusion, identification tags should be attached to any pat&cord setup
which is to be left in place at the end of a Technical
Controllers duty shift. The identification tag should
contain the following minimum information: circuit
number, terminal locations, using agency, mode of
operation, authority, and time to be taken down.
b. Patching Technique and Sequence. When patching operational circuits, it is essential that interruption, or service outage resulting from the actual patching procedure, be kept to an absolute minimum duration. In most patching operations, it is possible to limit
the effect on a VP circuit to a momentary click, and on
a TTY circuit to a few garbled characters. This minimum effect can be realized, however, only when the
Technical Controller selects and follows the correct sequence in inserting the plugs in the jacks. The order in
which this is done is important. Each of the many possible patching operations must be considered individually to determine the optimum order of events in the
patching procedure. Experienced Technical Controllers always take a moment to think out the whole
patching procedure before plugging into the jacksets.
In general, the spare or alternate signal path should
be set up first. The plugs should then be loosely set in
the proper NORMAL-THROUGH jacksets, located in
the signal path of the circuit to be transferred. Finally,
in a coordinated procedure, the plugs should be simultaneously pushed all the way into the NORMAL
THROUGH jacksets at two locations that constitute
the end of the substitution path.
4-19. Reporting Patching Operations
Patching operations which result in reconfiguration of
4-6
channels, rerouting of circuits, or cause interruption of
service must generally be reported to higher headquarters. The specific reporting procedures to be followed
are contained in the current station SOP.
a Equipment Substitution. No operations reports
are required for the substitution of equipment during
routine maintenance operations. A Failure Report
must be completed, however, if an equipment failure
has occurred.
b. HF Patching. Except as authorized in the current
SOP, group patches may not be performed in the
multiplex ares without prior coordination with, and
approval of, the DCA and ACC. Notice must be furnished to the DCA and ACC following completion of
the HF patching operation.
c. Channel Substitution. The DCA sad ACC must be
informed when a circuit is transferred to a spare channel, or to a channel of lower priority circuit. The notice
should specify the time, circuit number, channel designator, reason, and expected duration of the rearrangement. This report is normally submitted after-the-fact,
since the Technical Controller must take immediate
action when patching is required to restore service.
When it is necessary to preempt a lower priority circuit to obtain a substitution channel, the using agency
must also be informed. When the circuit is restored,
the using agency and higher headquarters must be
notified.
4-20. Patching Operations Condu
the VF Patching Facilities
a. General. The jackfields associated with the VF
patching facilities are used to gain access to signals in
voice-frequency (300 to 3400 Hz) circuits for monitoring purposes, and to perform circuit rerouting, test
measurements, level adjustments, and restoration of
service by equipment substitution. Representative
patching operations are given in b, c, and d below. The
patch panels and jacks used are discussed in Chapter 2.
The patching operations are shown in figures 4-1
through 4-3.
NOTE
The patching operations described below do
not take into consideration the extension of
E&M signalling leads through a patch panel.
Where there is a signalling lead extension,
use additional patch cords to transfer over all
portions of the circuit.
b. Transfer of a Circuit to a Spare Multiplex
Channel (fig. 4-1). The situation requires, for test or
maintenance purposes, that the user assigned to
channel 5, be transferred to channel 2. This patch is
made at the equal level patch panel (fig. 2-15) and the
procedure is the same for Station A and Station B.
(1) Place two patch cord plugs loosely into channel
2 REC LINE and TRANS LINE jacks.
TM 11-5895-1012-10
(2) Place the plugs on the other end of the patch
cords loosely into the channel 5 REC EQU and TRANS
EQU jacks.
(3) Establish voice contact between the Technical
Controllers at Station A and Station B.
(4) One Technical Controller will take charge and
on a prearranged signal, usually the count-of-three, all
loose plugs are set into the jacks simultaneously.
(5) The transmit aide of the patched off channel
(in this case channel 5) is terminated with a 600-ohm
termination plug set into the TRANS LINE jack.
c. Transfer of an Active (Circuit to a Spare Cable
Pair (fig. 4-2). The situation requires that for test or
maintenance purposes, the active circuit or channel 5
be transferred to the tail segment cable pair for spare
channel 2. This patch is made at the primary patch
panel (fig. 2-15) at Station A and the Patch and Test
Facility patch panel at the other end of the cable. The
patching operations are the same at both ends of the
cable. Only the patching operation at the TCF is covered below.
(1) Place two patch cord plugs loosely into the
channel 2 REC LINE and TRANS LINE jacks.
(2) Place the plugs on the other end of the patch
cords loosely into the channel 1 REC EQU and TRANS
EQU jacks respectively.
(3) Establish voice contact between the TCF and
the PTF.
(4) The Technical Controller will take charge and
on a prearranged signal, usually the count-of-three, all
loose plugs are set into the jacks simultaneously.
d. Substitution of Line Conditioning Equipment
(fig. 4-3). The situation requires that for test or maintenance purposes, the spare line conditioning equip=
ment (channel 2) be substituted for the active line conditioning equipment (channel 5). Before the patch is
made, check the spare channel line conditioning equip
ment to make sure it is configured the same as the
active channel. The patching is accomplished at the
primary and equal level patch panels (fig. 2-15) at Station A. Since the patch panels are normally physically
separated, two Technical Controllers are needed to
perform the operation with minimum interference to
the users. The procedure described below is the same
at both patch panels.
(1) At the equal level patch panel, place two patch
cord plugs loosely into channel 5 REC LINE and
TRANS LINE jacks. Place the plugs on the other end
of the patch cords loosely into the channel 2 REC EQU
and TRANS EQU jacks respectively.
(2) At the primary patch panel, place two patch
cord plugs loosely into the channel 2 REC EQU and
TRANS EQU jacks. Place the plugs on the other end of
the patch cords loosely into the channel 5 REC LINE
and TRANS LINE jacks respectively.
(3) Establish voice contact between the two patch
panels. On the count-of-three, all loose plugs are set
into the jacks simultaneously.
(4) On the equal level patch panel, terminate the
channel TRANS LINE with a 600-ohm termination
plug set into the TRANS LINE jack.
4-21. Patching Operations at Dc Patching
Facilities
a. General. The jackfields in the Dc patch bays are
employed to gain access to Dc circuits for monitoring
purposes and to perform circuit rerouting, test
measurements and restoration of service by equipment
substitution. Representative patching operations are
given in b, c, and d below. A cut-key is provided to
interrupt a telegraph channel for tactical considerations, or for the correction of an operational fault
condition at either the subscriber station locations. In
the event a condition exists which caused the teletypewriter equipment at the locations to run open,
the Technical Controller activates the appropriate cutkeys to isolate the subscriber loops affected and applies hold battery to the subscriber teletypewriter
machines. Upon correction of the condition, the cutkeys are restored to normal position. When a cut-key is
activated, the following actions occur: the telegraph
circuit is interrupted, hold battery is applied to the
channel terminating unit and the associated cut lamp
indicator is activated. This cut-key is also employed for
scheduled interruptions of circuits such as those encountered with high frequency radio systems.
b. Transfer of a Dc Circuit to a Spare VFCT Channel
(fig. 4-4). The situation requires that for test or maintenance purposes, a teletypewriter circuit is to be
transferred from VFCT channel 1 to a spare or lower
priority channel 2. The patching operation is
accomplished at the equal level dc patch panel at both
the local and distant station. Coordination is required
so that the patch is made simultaneously at both ends
of the communications path to preclude loss of large
blocks of record traffic.
(1) Place two patch cord plugs loosely into the
channel 2 REC LINE and TRANS LINE jacks.
(2) Place the plugs on the other end of the patch
cord loosely into channel 1 REC EQU and TRANS
EQU jacks respectively.
(3) Establish voice contact with the distant station. One Technical Controller will take charge and on
a prearranged signal, usually the count-of-three, all
loose plugs are set into the jacks simultaneously (at
both ends of the circuit).
c. Transfer of a Dc Circuit to a Spare Digital Line
Interface Unit (DLIU) (fig. 4-5). The situation requires
that for test or maintenance purposes, a teletypewriter
circuit is to be transferred from the DLIU associated
with channel 1, the normal channel, to the spare channel 2 DLIU. Before the transfer can be made the spare
4-7
TM 11-5895-1012-10
Figure 4-1. Transfer of circuit to spare multiplex channel at the equal level patch panel.
4 - 8
TM 11-5895-1012-10
Figure 4-2. Transfer of current to spare cable circuit at the primary patch panel.
4-9
TM 11-5895-1012-10
Figure 4-3. Substitution of line conditioning equipment using the equal level and primary patch panels.
4-10
TM 11-5895-1012-10
Figure 4-4. Transfer of a Dc circuit to a spare VFCT channel.
4-11
TM 11-5895-1012-10
patching is accomplished at both the equal level dc and
primary dc patch panels. Since the patch panels are
normally physically separated, two Technical Controllers are needed to perform the operation with
minimum interference to the user. The procedure
described below it the same at both patch panels.
(1) At the primary dc patch panel, place two patch
cord plugs loosely into channel 1 REC LINE and
TRANS LINE jacks. Place the plugs on the other end
of the patch cores loosely into channel 2 REC EQU and
TRANS EQU jacks respectively.
(2) At the equal level dc patch panel place the
patch cord plugs loosely into the channel 1 REC LINE and
TRANS LINE jacks. Place the plugs on the other end
of the cords loosely into channel 2 REC EQU and
TRANS EQU jacks respectively.
(3) Establish voice contact between the two patch
panels. On the count-of-three, all loose plugs are set
into the jacks simultaneously.
transferred to the tail segment cable pair for spare
channel 2. This patch is made at the primary dc patch
panel (fig. 2-15) and the Patch and Test Facility, or
similar patching facility, at the other end of the cable.
The patching operations are the same at both ends of
the cable. Only the patching operation at the TCF is
covered below.
(1) Place two patch cord plugs loosely into the
channel 2 REC LINE and TRANS LINE jacks
(2) Place the plugs on the other end of the patch
cords loosely into the channel 1 REC EQU and TRANS
EQU jacks respectively.
(3) Establish voice contact between the TCF and
PTF.
(4) The Technical Controller will take charge, and
on a prearranged signal, usually the count-of-three, all
loose plugs are set into the jacks simultaneously.
Section IV. FAILURES AND FAULT ISOLATION
4-22. General
a. All transmission media with breakout capability
entering a DCS Station appears on the jack fields in
the Technical Control Facility for control and restoral
b. The Technical Controllers are responsible for all
transmission media entering, terminating or transiting a DCS Station.
(1) All traffic will be stopped where practicable
before any action is taken that will interrupt its flow.
When actions can be predicted; e.g. scheduled maintenance, the user will be notified in advance in order
that traffic may be stopped at the scheduled time.
(2) Occasionally, traffic will be interrupted due
to unforeseen events, such as transmission media
degradation or equipment failure, Traffic may also be
interrupted by preemption of the circuit to restore a
higher priority user. In all such cases, the user will be
notified of the transmission media failure or preemption to permit them to stop traffic and maintain continuity.
4-23. Circuit Outages
The Technical Controller is responsible for identification of all outages or interruptions on the circuit. Technical Controllers are also responsible for restoration of
service with minimum loss of operating time. Controllers will test, monitor, and observe outgoing and
incoming circuits and channels to ensure proper operation. They will coordinate with distant stations and
local users, as necessary to isolate the report troubles.
4-12
All service interruptions must be logged, regardless of
period of outage.
4-24. fault Isolation
Fault isolation is the process of determining the location of a trouble within a circuit, or within the transmission media which carries the circuit The trouble
could be in any of the transmitting facilities of one station, the receiving facilities of the adjacent station, the
media connecting them, or the user's equipment which
terminates the circuit. After the general area of a
trouble has been isolated; e.g. media, user equipment,
access lines, etc., a decision can be made to provide the
quickest method of restoral. Fault isolation is not a
finger-pointing or blame-fixing exercise. The basic
purpose is to locate the source of a trouble and get it
fixed, regardless of where it is, or which piece of equip
ment is at fault. The same problem recurring at frequent intervals is of prime concern to both DCA and
the operation and maintenance agency, and corrective
measures must be taken. However, this is a byproduct, not the purpose of fault isolation.
a. The first step in fault isolation is the recognition
that a problem exists. On the surface, fault recognition
may seem to be a trite statement. However, the majority of problems are the result of someone failing to
recognize that trouble signs are appearing. Trouble
recognition may be a result of quality control testing,
equipment sensors and alarms, customer complaint, or
any combination of these. The main point is that when
the trouble signs appear, regardless of how or from
TM 11-5895-1012-10
Figure 4-5 Transfer of a DC circuit to a spare digital line interface unit (DLIU).
4-13
TM 11-5895-1012-10
Figure 4-6. Transfer of a circuit to a spare cable pair.
4-14
TM 11-5895-1012-10
a system such as the DCS, there is little room for error.
Even the smallest error can easily be compounded into
a series of errors which can render a circuit, group, system, or service completely unuseable. Every station
and link in the system was originally tested and accepted as meeting a specified level of performance. In
order to continue operating at that level, each and
every one of the electrical standards must be maintained with the established parameters.
c. The DCS is made up of many different types of
equipment which perform identical functions, but do
not necessarily have the same electrical characteristics. For example, not all of the voice frequency channel multiplex equipments in the DCS are designed for
a - 16 dBm test tone level input to the voice frequency
modulator. Because of the detail differences which
exist, there are no cut and dried, test-point by testpoint fault isolation procedures which cover all possible installations. There are certain functional areas
which are the same in all systems, regardless of the installed equipment The procedures given in this section are addressed to functional areas rather than specific signal and test tone levels at the various equip
ments. In addition to general fault isolation procedures, specific fault isolation procedures for the more
common faults are also presented.
4-25. Responsibilities
Responsiblity for maintaining the DCS at a high level
of operation, rests not only with the DCS Stations and
Technical Controllers, but also with the user, the DCA
and ACC Operations Centers, and Maintenance personnel.
a DCS Station.
(1) Each DCS Station is responsible for the
development of local fault isolation procedures based
on the particular type of equipment installed in that
station, the design capability of each link or system,
patch panel and test point appearances, and test equipment availability. The procedures clearly delineate
those functions which will be performed by technical
controllers and those which will be accomplished by
maintenance personnel.
(2) Each station should have ready reference
charts at or near each patch panel or test point showing the required teat tone level, the signal and noise
levels, and the allowable tolerance at that test point,
This data is gotten from the technical evaluation made
at the time the equipment, link, or system was accept
ed.
(3) The requirement for maintaining the correct
input or output signal levels cannot be over-emphasized. One or two voice channels operating with excessive signal levels can disrupt the entire baseband In
fact, high levels inserted into one channel can disrupt
other links or systems through which that signal is
routed. By the same token, a change in signal level at
one point will affect the level at all subsequent points
in the system. Signal level adjustments must not be
made without complete coordination with all locations
that can be affected. equipment adjustments made by
Technical Controllers will normally be limited to operational controls which are necessary for proper circuit
or trunk operation; i.e., line current levels, composite
audio levels, mode changes, channel reduction, or
paralleling (twinning). They will not normally adjust,
or attempt to adjust, any of the controls used for
equipment alignment.
(2) When a &graded condition or other trouble is
encountered at a given station, the Technical Controller of that station coordinates with distant stations,
local users, and associated transmitting and receiving
elements in his efforts to isolate and locate the fault.
He has primary responsibility for this action, and must
receive full cooperation from all other station Technical Controllers involved. When it is determined that
the fault is located at a distant station, or in a link
serving an area beyond that station, responsibility for
locating and correcting the fault is transferred to, and
assumed by, the station Technical Controller primarily
concerned.
c. User. The user is responsible for notifying the responsible Technical Controller of all instances of service degradation evidenced by high data error rates, occasional noise bursts into the voice channels serving
him, or other indications of unsatisfactory conditions.
The user renders free cooperative to the Technical
Controller and the correction of service degradation.
d. DCA and ACC Operations Center.
(1) The Operations Centers monitor the progress
of the station Technical Controllers in their troubleshooting efforts, but under normal circumstances,
does not actively engage in the isolation of a fault. If
however, the station Technical Controllers encounter
difficulties and cannot restore service within a reasonable period of time, the active Operations Center is responsible for assuming the overall direction of the corrective actions, for providing a workable solution to
the problem, and for keeping circuit outage time to an
absolute minimum.
(2) Troubles encountered on multichannel or
multilink circuits often are of an accumulative nature
and present a complicated condition for resolution. To
determine the cause, or causes of such a condition special link and segment tests may be required. The DCA
and ACC are responsible for determining the requirements for such special tests on the basis of station re
4-15
TM 11-5895-1012-10
ports. The Operations Center coordinates the tests,
collects and analyzes the results, and directs remedial
actions as necessary.
(3) Unless there are definite indications of a major
abnormality the Operations Center normally does not
take immediate action to inquire about circuit conditions, inasmuch as continuous inquiries by the Center
impedes the troubleshooting and fault correction actions of the station Technical Controller and maintenance personnel. The Operational Center is responsible,
however, for investigating outages which have not
been cleared after a reasonable period of time, or if no
explanation has been made by the remote stations or
the cognizant master station, and for rendering assistance in restoring service.
e. Maintenance Personnel. After faults have been
located and identified, maintenance personnel are responsible for effecting necessary repairs and maintenance in accordance with appropriate technical manuals pertinent to the particular item of faulty equip
ment.
4-26. F u n c t i o n a l A r e a s
a. For purposes of fault isolation, a Technical Control Facility will fall into one of the following three
functional areas:
(1) A Technical Control Facility which provides
the user with access to the Defense Communications
System; i.e., the serving TCF.
(2) A TCF which has voice frequency channel
breakout, but does not provide the user a direct access
to the DCS; i.e., a receive channel of one group is crossconnected to the send channel of another group..
(3) A TCF in which the signals appear at a group
or supergroup level, i.e., no vf channel breakout.
b. It is possible that a Technical Control Facility
could be involved in more than one functional area at
one time, depending upon the circumstances at that
particular time and station configuration.
4-27. Troubleshooting Practices
a. Fault Notification. Technical Controllers are
alerted to actual, or impending circuit outages by
means of alarm indicator displays, by notification
from the user, of circuit deterioration or failure by a
distant Technical Controller, and as the result of test
ing and monitoring.
(1) The supervisory alarm subsystems provide an
alarm when a failure occurs in various equipment and
systems at the DCS Station, such as single frequency
signaling equipment, ringers, multiplex systems, fuse
panels, or the dc power system. When alerted to an abnormal condition by an alarm, the Technical Controller and maintenance personnel must perform systematic step-by-step monitoring, or testing of the system
segments into, through, and out of the station, in or
4-16
der to isolate the fault(s) to specific areas and/or equip-
tivate the supervisory alarms, and consist
noise bursts in the circuit data error rates,
channel levels. Usually, these problems are brought to
the attention of the Technical Controller by the user.
The Technical Controller performs monitoring and
testing routinely, as circumstances permit. However,
when notified of degrading circuit conditions by the
user, other Technical Controllers, or maintenance personnel, monitoring and testing of the degraded circuit
in the Technical Control areas, provide a means of sequential access to circuits and groups between most of
the major equipment in the station.
b. Service Restoration. The Technical
must use every means at his disposal to
rupted service as expeditiously as possible. These
means, when available, should be used in the following
order of priority:
(1) If a spare channel is available, the Technical
Controller should patch the user circuit or group into a
spare, while isolating and correcting the defective
equipment.
(2) If a fault is identified within an item of equip
ment for which a standby or spare is available, the sub
stitute equipment should be used to restore disrupted
service while the defective equipment is being restored.
(3) During prolonged, or projected extended outages, the Technical Controller should request alternate
routing instructions. Rerouting or pre-empting is obtained from a list in the station SOP.
(4) As a last resort, the Technical Controller
should pre-empt lower priority circuits in order to restore service for high priority users. Every circuit, including switchboard trunks as well as allocated circuits, is assigned a priority of restoration which must
be adhered to in channel restoration. Establishment of
these priorities is performed on a worldwide basis by
the Defense Communications Agency.
C. Records and Reports. The Technical Controller
who first determines that a fault exists or to whom a
fault is reported by a user, is responsible for coordinating the fault-isolation activities with distant station
Technical Controllers, and is responsible for appropriate log entries and reports. When a fault has been
isolated, an explanation of the nature of the trouble
must be entered in the reporting station log, and the
distant Technical Controller must be notified so that
the entries for both stations coincide. All circuit out
TM 11-5895-1012-10
ages must be recorded on the appropriate station logs,
of the duration of the outage time or the
cause of the fault. Specific instructions for reporting
of stations are contained in Standard Operating Procedures published by DCA and ACC. Trouble reports
(work orders) must be prepared for each equipment or
circuit failure. This work order will notify maintenance of the faulty or sub-standard equipment- Only
by strict adherence to this procedure can proper records be maintained. Prompt, efficient repair of faulty
equipment often depends upon the completeness and
accuracy of these symptoms described on the written
workorder.
d. Catastrophic Failure. Normally, the Technical
Controllers keep DCA and ACC informed of anticipated, imminent, or existing service failures or degraded
conditions which are beyond the local capability to restore within a tolerable delay or outage time period. In
an exceptional case, a catastrophic failure condition
may be encountered in which the alarm indicator display may depict a number of simultaneous alarms or
provide an indication of a second major alarm within
the same station before the first alarm has been
cleared. In these cases, DCA or ACC may provide alternate routing instructions, or other solutions, as applicable.
4-28. Fault Isolation Procedures
The guidelines contained in paragraphs 4-29 through
4-34 are for use in preparing local procedures and in
determining the location of the equipment or media
which is causing signal degradation. It may not be necessary to take each step in the order listed. Depending
upon the trouble indications, it is possible that some
steps may be taken in different sequence, combined
with other steps, or even eliminated completely. A
Technical Controller’s first questions, when a problem
is recognized, should be “Does the problem affect only
a single circuit or channel, or the entire group or supergroup?” and then, “Is the circuit, group or supergroup
meeting the standards through my station?” The Technical Controller must then take the actions necessary
to answer those questions. All steps will be taken in
complete coordination with the other stations through
which the signal is routed, and with the local maintenance activity.
a. Fault isolation should proceed from the point of
fault recognition toward the signal source to the point
where the fault exists. Results of in-station checks will
be completely coordinated with the other concerned
TCF's and the trouble corrected at the source. Adjust
ments will not be made at intermediate points to compensate for a problem generated at some other point in
the circuit or system.
b. In the event a known fault cannot be corrected
within a reasonable amount of time (i.e., 10 minutes),
the Technical Controller should reroute or restore in
accordance with established restoration priorities,
pending completion of repairs. Difficulties encountered in obtaining a reroute path will be reported to the
appropriate DOCC and reroute instructions will be requested.
4-29. Voice Frequency Fault Isolation
When a Technical Controller discovers that a circuit or
a multiplex group is not operating within established
parameters, in-service monitoring tests should be performed in accordance with established station procedures. This will help determine whether a single channel, an entire group or supergroup, or the baseband is
affected. In addition, whether the fault is located within the station multiplex or line conditioning equip
ment. Time is important. The goal is to locate and correct the fault before the users service becomes unuseable.
a. In coordination with the distant station(s) and the
appropriate control office(s), using available orderwires, selective elimination of each portion of the circuit may be used to locate the fault area. In-station
monitoring procedures will locate the fault specifically
enough to permit the Technical Controller to modify
established fault isolation procedures and attack the
problem directly, either by substituting for the faulty
item, or by making a patching substitution. Then
through the use of out-of-service testing procedures, or
the in-station test and alignment procdures, correct
the problem.
b. Keep in mind that the fault isolation procedures
established, serve only as a guide for efficient technical control operations and do not represent a rigid sequence of steps which must be followed to solve a problem. The Technical Controller should by-pass any unnecessary steps in order to quickly locate the fault and
restore normal service.
4-30. Single Voice Frequency Channel
Fault
When it is determined that a single voice channel of a
voice frequency group is unuseable or deteriorated, the
station Technical Controller will take the following action:
a. Coordinate with the distant station Technical
Controller to transfer service to a spare channel, or
preempt a lower priority user if required. If a low priority user is preempted, have the distant station Technical Controller notify the low priority user of the preemption.
b. Request the distant station Technical Controller
to send a test signal on the faulty channel in accordance with the appropriate out-of-service test procedure
after the traffic signal has been moved to another
channel.
4-17
TM 11-5895-1012-10
4-31. Multichannel Fault
following actions:
a Determine whether alternate equipment is available for substitution.
b. If none is available, notify the distant station
Technical Controller to block the use of the faulty
channels, and to send test signals on specific channels,
preferrably on voice frequency channels 1, 6, and 12 of
the affected group.
c. Notify local users of circuit failure.
d. Monitor the test signals transmitted by the distant Technical Control Facility. In conjunction with
station maintenance personnel, coordinate maintenance necessary to restore the multiplex group or
supergroup equipment to proper transmission standards by alignment, replacement, or repair. If the malfunction cannot be isolated or corrected within a reasonable length of time (i.e., 10 minutes), service will be
restored in accordance with established procedures
and assigned restoration priorities.
e. When the malfunction has been isolated, corrected, and the circuits checked out, notify the distant
Technical Control of the nature of the problem end
request removal of test signals. If necessary perform
additional out-of-service testing to ensure that all circuits meet specified parameters.
f. Restore user service to normal routing.
g. Complete station records, trouble reports, log entries, etc., in accordance with established procedures.
4-32. Baseband Fault
When it is determined that the entire transmission
media baseband has deteriorated, the station Techi4-18
f. Measure the group regulation pilot
transmission media monitor jacks with
selective voltmeter and spectrum analysis at both
terminals. Make certain that the levels are in accordance with appropriate subsystem block and level
diagram and that they are free of noise.
frequency signal, as
is excessively noisy
indications at the
(i.e., 10 minutes), the Technical Controller should
notify the appropriate DOCC and request rerouting
instructions for any priority circuits that may be involved.
h. Connect a frequency selective voltmeter and a
spectrum analyzer to the transmission media baseband
monitor jack to test for interference or man-made
noise at the receive terminal. Observe the baseband
signal for noise pulse or interfering signals.
i. Work with the maintenance personnel as they alternately deactivate the individual receive while observing the baseband signal and multiplex performance to determine the frequency sensitivity (interfering effect) of unwanted signals or to isolate a defective receiver.
j. Request alternate deactivation of the frequency
diversity transmitters to ensure that unwanted signals
or noise are not caused by the distant end transmitters. Direct maintenance personnel to perform transmitter and common baseband equipment tests to
verify normal operation.
k. If the fault has not been isolated at t&is point in
the test procedure, request deactivation of both transmitters. Monitor the receiver output on the oscilloscope and the automatic gain control (AGC) meters.
The presence of noise spikes or pulses indicates either
radio interference or local man-made noise. Noise may
be caused by many things, including defective antenna
TM 11-5895-1012-10
o r e q u i p m e n t to more than one receiver.
l. Direct maintenance personnel to perform receiver
common base-band equipment tests to verify noroperation.
m. Test the common circuitry of the multiplex terminal.
n. When the malfunction has been isolated and cornotify the distant Technical Controller of the
of the problem and request removal of the test
signal. If necessary perform additional out-of-service
testing to ensure that all circuits meet specified
o. Restore user service to normal when the corrective action has cleared the malfunction.
p. Complete station reports, trouble reports, log entries etc., in accordance with the established procedures.
4-33. Dc Fault Isolation
When the Technical Controller discovers that one or
more dc circuits are not operating properly, in-service
monitoring tests should be performed in accordance
with established station procedures to determine if a
single channel or the entire VFCT group is faulty. If
the entire VFCT group is affected, the Technical Controller must continue monitoring to determine
whether the fault is within the voice frequency sub
system, the multiplex channel equipment, or the local
or distant VFCT equipment. If the fault is not in the
VFCT equipment, the controller should refer to paragraphs 4-28 through 4-32 and apply the applicable
procedures. Multichannel faults not involving the
voice frequency subsystem or multiplex channel equip
ment are limited to send or receive VFCT equipment.
The Technical Controller should proceed immediately
to effect isolation of the fault within the portions of
the VFCT which are common to all channels. Single dc
channel faults may be located by coordinating with the
distant station to selectively eliminate each portion of
the circuit which is performing properly. In-station
monitoring procedures may often locate the fault to a
general area which will permit a modification of the
fault isolation procedures and attack the problem
directly, either by substitution of equipment by patching or replacement of equipment. Out-of-service testing procedures or in-station test and alignment procedures can then be applied to locate and correct the
fault.
a. When it is determined that one channel of a
multichannel VFCT system is unuseable, the Technical Controller should proceed as follows:
(1) Coordinate with the distant Technical Control
Facility to restore service on a spare channel or preempt a low priority user. If a low priority user is preempted, have the distant Technical Controller notify
the user of preemption of the circuit.
(2) Request the distant Technical Control Facility
to send a teat signal on the faulty channel.
(3) If the results of the test procedure are unsatisfactory at a certain point, the trouble will have been
isolated to that particular area. In such a case, proceed
as follows:
(a) In coordination with the distant technical
control, determine which equipment is at fault (for example, VFCT keyer or converter, line conditioning
equipment, etc.).
(b) Coordinate the equipment repair or alignment required tocorrect the fault.
(c) If equipment is found to be unuseable, coordinate with station maintenance personnel for its replacement.
(d) After repair or replacement, perform the appropriate test to ensure proper operation of the circuit.
(e) Notify the user that the fault has been
cleared, and restore service to the normal route. Service shall always be returned to the normally assigned
channel at the earliest possible time.
(4) When the test signal from the distant TCF is
satisfactory, request a test signal from the distant sub
scriber to determine whether the fault is between the
distant subscriber and distant Technical Control Facility or between the local TCF and its subscribers. The
Technical Controller at both ends of the circuit should
monitor the subscriber’s test signal, and in that way
isolate the fault area.
(a) Coordinate the repair or alignment required
to provide service between the DCS Station and the
local subscriber.
(b) Perform the appropriate tests to ensure
proper operation of the circuit over the lines between
the DCS Station and the local subscribers.
(c) Notify the user that the fault has been
cleared, and restore service to the normal route.
(5) Complete station records, trouble reports, log
entries, etc., in accordance with the established procedures.
b. When it is determined that all channels within a
multichannel VFCT system are unuseable, the Technical Controller shall proceed as follows:
(1) Notify the distant Technical Control Facility
to block user input on all channels. Notify users that
the circuit has failed, and deactivate all traffic equipment.
(2) The cause of failure could be in the voice frequency channel or in the VFCT equipment. Perform
the voice frequency fault isolation procedures as described in paragraph 4-30.
(3) If the results of (2) above are satisfactory, request the distant TFC sent a test signal on specific
channels. Channels 1, 8, and 16 of the VFCT equip
ment are preferred test tone channels. Proceed as follows:
4-19
TM 11-5895-1012-10
(a) Check the level of the multichannel VFCT
tones at the voice frequency patch panel and instruct
(4) When the trouble has been isolated and corrected by coordinating the maintenance necessary to
restore operations, notify the distant Technical Controller of the nature of the problem and restore the
.
user circuits to normal.
(5) If the malfunction cannot be corrected in a
reasonable length of time (Le., 10 minutes), the Technical Controller should notify the appropriate DOCC
and, if required, request rerouting instructions for priority channels pending the completion of repairs.
(6) Complete station records, trouble reports, log
entries, etc., in accordance with established procedures.
4-34. Commercial
Procedures
Initial testing will be conducted to determine whether
the reported trouble is in the local terminal portion,
distant terminal portion, or in the leased portion of the
circuit. So that such testing can be accomplished, it is
essential that all parties concerned definitely understand the extent of their responsibility.
a. Military terminals are responsible for establishing proper circuitry, correct operation of equipment
and circuitry from and to the terminals where the
commercial carriers responsibility begins at the interface points.
b. The commercial carrier is responsible for establishing and maintaining the type of service requested
by the military between the designated terminals. This
includes troubleshooting and restoration of service up
to the interface points. The following action will be
taken:
(1) Call the appropriate commercial circuit control
office for trouble reporting.
(2) Provide an account of the trouble indicated according to results obtained from tests.
(3) The nature and indications of common
troubles encountered on leased or military circuits are
listed below. The terms listed have been chosen so that
the nature of the trouble will be understood by commercial carrier personnel throughout the world who
have contact with the DCS.
(a) No receive current or signal.
(b) Cannot receive ringing current.
(c) Levels too low.
(d) Excessive noise.
(e) Intense crosstalk.
4-20
(3) Telephone numbers.
(4) Date, time and trouble number.
(5) Station reported to.
(6) Names or initials of
coordinator.
d. Inquiries concerning
status of reported
carrier will provide information as
concerning the status of the circuit
The commercial carrier may include probably location
of trouble switch to an alt-route, but they are not
required to furnish more detailed information. Only
information concerning restoral of circuit or in-effect
between the commercial
4-35. Examples of Voice Channel Fault
Isolation Procedures
There are a number of acceptable methods of isolating
a faulty link in a communications channel. Two methods are explained in this paragraph . The first method
(discussed in a and b below) requires the isolation procedure to begin at the point of fault recognition. Each
site clears itself of any responsibility for fault by
sponsible TCF to isolate the fault over the whole communications chain by having the signal from the local
TCF looped back and tested at various points in succession along the chain
a. Noise Burst on Multiplexed Through Circuit. The
procedure followed is outlined in flow-chart fashion in
tant Technical Controller is notified
figure 4-7. Th
that noise bursts are being received by a subscriber.
The complaint has been verified at the distant end,
and that station has been cleared of causing the
trouble. The noise bursts are incoming to the distant
Technical Control Facility, and that Technical Controller requests that the local Technical Controller
clear the local station of being the cause of the noise
bursts. The local controller is responsible for simply
checking the circuit through the site to determine if
the fault source is in the station, reporting back to the
distant station, and correcting the fault if necessary.
Following is an example of an isolation procedure for
this type of fault:
(1) At the equal level patch panel farthest from
the complaining subscriber, connect a loudspesker to
the receive monitor jack of the affected circuit.
(2) Listen for the noise burst complaint.
TM 11-5895-1012-10
action to clear the problem,
responsible
Technical Control Facility of the source of the trouble,
action taken, and complete station records in accordance with established procedures.
(9) If, after maintenance personnel have checked
the equipment, the source of trouble is not at the local
station, notify the responsible TCF so that fault isolation may continue at points closer to the signal
(10) Standby to assist in patching
or
other fault isolation tests if it should be necessary.
(11) If noise is not present, then the source of
trouble is somewhere between this point and the complaining subscriber. This includes the local station
transmit multiplex and transmission media equipment
Figure 4-71.
Noise Burst on multiplexed through circuit, fault isolation flow chart (sheet 1 of 2)
4-21
TM 11-5895-1012-10
(12) Perform the tests described in (1) through (3)
above at the equal level patch panel closest to the complaining subscriber.
(13) If noise bursts are present, then the trouble is
located somewhere within the local TCF. The responsible Technical Control Facility and local maintenance
personnel should be notified. Take action to clear the
fault and report in accordance with established station
procedures.
(14) If noise bursts are not present, request that
local maintenance check the transmit side of the circuit towards the complaining subscriber for the possible sources of trouble. Should the local station transmit side be faulty, take action to have the trouble
cleared and consider what action must be taken, similar to that outlined in (7) above.
(15) Notify the responsible TCF of the source of
trouble, action taken and complete station records in
accordance with established procedures.
with established procedures.
b. Noise Burst on a Local Subscriber Circuit. The
procedure followed is outlined in flow-chart fashion in
figure 4-8. The Technical Controller is notified by a
connected subscriber that frequent noise bursts are
being received. The local Technical Controller has
responsibility for coordinating fault isolation procedures at distant station which may be involved; but,
first if must be determined whether the local station is
at fault. An immediate decision must be made whether
to patch the affected circuit over to a spare channel
This decision is influenced by the priority of the circuit
Figure 4-72. Noise burst on multiplexed through circuit, fault isolation flow chart, (sheet 2 of 2)
4-22
TM 11-5895-1012-10
encountered, proceed to (6) below.
(3) Notify local maintenance personnel of the
problem and request the multiplex equipment be
is local. If the fault is
at this point indicates the fault lies between the
level patch panel and the signal source. This
trouble by substituting for the defective channel
equipment. If the noise is found to be across the entire
group, consider patching at the group level, replacing
defective equipment, or if the outage may be long in
duration, (i.e., longer than 10 minutes), rerouting circuits in accordance with established procedures and
priorities.
(5) After the fault is cleared, restore any rerouted
Figure 4-81. Noise burst on a local subscriber circuit, fault isolation flow chart (sheet 1 of 3).
4-23
TM 11-5895-1012-10
circuits to their normal path. Complete station records
in accordance with established procedures.
(6) If the local station proves not to be the source
of trouble, as the responsible TCF, proceed with
established fault isolation procedures through
coordination with other TCF's which
defective circuit.
(7) When the trouble
rerouted circuits to their
son for and location of
Figure 4-82. Noise burst on a local subscriber circuit, fault isolation flow chart (sheet 2 of 3).
4-24
TM 11-5895-1012-10
(11) Notify local maintenance personnel of the
problem. When the troulbe has been cleared, remove
any patches which have been established. Complete
station records in accordance with established
procedures.
(12) If noise is not encountered at the equal level
or primary patch panels, the fault is in the subscriber's
terminal equipment or the tie-cable.
. (13) Notify local maintenance personnel and
locate a spare cable pair.
(14) If extended circuit outage time is expected,
Figure 4-83. Noise burst on a local subscriber circuit, fault isolation flow chart (sheet 3 of 3)
4-25
TM 11-5895-1012-10
(15) After the fault has been cleared, remove any
patches which have been established and complete station records in accordance with established procedures.
c. Fault Isolation of a VF Subscriber Circuit by the
Loop-Back Method. This procedure followed is outlined
in flow-chart fashion in figure 4-9. The Technical
Controller is notified by a local subscriber that the circuit level is not correct. A spare channel is available
and the circuit is patched over onto the spare circuit so
that the normal path can be available for out-of-service
testing. The basic procedure is to clear the local station
Figure 4-91.
4-26
send point of the same channel under test at the equal
level patch panel.
(3) The local Technical Controller inputs a 1
Hz test tone on the send circuit at a level of 0 dBm at
the equal level patch panel. The same test tone should
Vf subscriber circuit loop-back, fault isolation flow chart (sheet 1 of 2)
TM 11-5895-1012-10
that channel's receive circuit on
panel at a level of 0 dBm. If the
leg of the defective channel has
If the level is not correct, the fault has
isolated between the two TCF’s and the trouble
can be turned over to maintenance personnel.
(4) If the tone looped back is received at the
proper level, the distant TCF is requested to remove
the loop back patch and the next TCF further toward
the signal source is requested to perform a similar
patch. Again the local TCF inputs a 1000 Hz tone at
0 dBm and measures the level of the looped back tone.
Following this procedure, trouble can be isolated between any two equal level patch panels in the channel.
(5) When the fault has been located in the defective circuit, the tasks is turned over to maintenance
personnel to clear the trouble. After the fault has been
cleared, restore the circuit to its normal path, obtain
the reason for the fault and location, and complete station record% in accordance with established pro=
cedures.
4-36. Examples of a Dc Circuit Fault Isolation Procedures
a. Open Circuit Condition. The station Technical
Control Facility is notified by a connected telegraph
subscriber that incoming traffic has been interrupted
and that the printer has started to run open.
Reference to the circuit layout record card indicates
that the subscriber circuit is connected by cable to a
nearby military installation. The most likely reason
for the condition reported is a break in the dc loop
cawed by failure of the loop battery, an open connection at the subscriber terminal, a defect in the cable, or
an electrical failure of the receiving equipment.
(1) Loop Battery Check. The Technical Controller
Figure 4-92 . Vf subscriber circuit loop-back method, fault isolation flow chart (sheet 2 of 2)
4-27
TM 11-5895-1012-10
should check the appropriate fuse panel (or associated
alarm output) to verify that no failure has occurred in
the loop current distribution system serving the
subscriber loop and associated DLIU. If, in fact, a
blown fuse alarm is received, the line should be
checked for a short circuit. If no short is detected, the
DLIU should be substituted and refused.
(2) Open Connection at Subscriber Terminal. If no
failure in the loop battery supply is detected, the Technical Controller should:
(a) Locate the jack appearances of the subscriber circuit at the dc primary patch panel and connect a current meter into a monitor jack appearance of
the transmit circuit (receive circuit of subscriber) to
measure the loop current.
(b) If no loop current is observed, connect a
voltmeter into the receive monitor jack appearance of
the defective circuit on the dc equal level patch panel.
Measure for a steady mark condition from the VFCT
equipment.
(c) If a steady mark condition is obtained,
substitute the DLIU through patching operations. Perform the test in (a) above. If no loop current is
measured, proceed to(g) below.
(d) If loop current is measured, notify maintenance personnel of the defective DLIU.
(e) Complete station records in accordance with
established procedures.
(f) After maintenance personnel have either repaired or replaced the defective DLIU, return the circuit to its normal routing.
(g) If no loop current was measured in (c) above,
the TCF interface equipment is not at fault. The break
is somewhere in the dc loop between the station and
the subscriber.
(h) Return the normal interface equipment to
the circuit by removing the patchcords.
(i) Isolate the defective subscriber loop from the
in-station circuits by inserting a shorting-type dummy
plug in the line transmit jack on the dc primary patch
panel.
(j) Request that user maintenance personnel
check the continuity of the subscriber loop.
(k) Upon verification that maintenance personnel have located and corrected the fault, insure
that the normal TCF interface equipment is connected
to the subscribers circuit.
(l) Remove the dummy plug from the line
transmit jack to reconnect the subscriber to the in-station circuit.
(m) Measure the loop current at the dc primary
patch panel to ensure the circuit is operating normally.
(n) Complete station records in accordance with
established procedures.
(3) Defective Cable. The Technical Controller is
notified that the reason for the open circuit condition is
4-28
a break in the cable between the DCS station and the
subscriber. The report indicates that the cable will be
out-of-service for some period of time. The Technical
Controller reviews the area circuit records and they
indicate that an alternate link is not available, or feasible, between the two communicating locations. Fur
ther, it is not practicable to copy the incoming traffic
at the TCF for use by the subscriber. The Technical
Controller should take the following action:
(a) Contact the distant Technical Control Facility and request that traffic be stopped to the sub
scriber until the fault has been cleared.
(b) Insert a dummy plug into the line transmit
jack (the subscribers receive circuit from. the TCF) at
the dc primary patch panel. This will isolate the sub
scriber loop from the in-station circuit.
(c) Upon notification by maintenance personnel
that the cable has been repaired, the Technical Controller should remove the dummy plug from the line
transmit jack at the dc primary patch panel to reconnect the subscriber loop to the in-station circuit.
(d) Notify both the subscriber and the distant
TCF that the circuit is ready for the passing of traffic.
(e) Complete station records in accordance with
established procedures.
(4) Defective Subscriber Terminal Equipment.
The Technical Control Facility is notified by maintenance personnel that the reason for the open circuit
condition is an electrical failure in the receiving equipment at the subscriber terminal. The Technical Controller should take the following actions:
(a) Insert a dummy plug into the line transmit
jack (subscribers receive circuit from the TCF) at the
dc primary patch panel to isolate the subscriber loop
from the in-station circuit.
(b) Notify the distant TCF that the circuit is
out-of-service and stop traffic from being transmitted
to this subscriber.
(c) Upon notification by maintenance personnel
that the equipment failure has been corrected, the
Technical Controller should remove the dummy plug
from the line transmit jack appearance at the dc
primary patch panel to reconnect the subscriber loop
to the in-station circuit.
(d) Provide a Fox test as required, so that main=
tenance personnel can ascertain that the receiving
equipment is adjusted properly.
(e) Complete station records in accordance with
established procedures.
b. Defective VFCT Channel Equipment. The Technical Control Facility is notified by a connected sub
scriber that service has been interrupted on the receive
circuit. The Technical Controller initiates fault isolation procedures. A zero indication is shown when a
voltmeter is inserted in a monitor jack of the subscriber receive channel at the dc equal level patch panel.
TM 11-5895-1012-10
The Technical Controller then actuates the cut-key of
the receive channel on the dc equal level patch panel.
If a cut-key is not available, the Technical Controller
inserts a dummy plug into the receive channel jack appearance at the dc equal level patch panel. This action
applies hold battery current to the loop, which prevents the receive equipment from running open. The
Technical Controller can then proceed with the following fault isolation procedure to determine if the fault
exists in the VFCT channel equipment, either in the lo=
cal station or at a distant terminal.
(1) Consult the station circuit files and identify
the voice frequency and tone channel assignments of
the dc subscriber circuit which is in trouble.
(2) Place the selector switch of the teletype carrier
test set to the designated tone channel, and connect
the unit to the voice frequency equal level patch panel
LINE transmit jack serving that channel of the VFCT
equipment.
(3) Patch the dc output of the VFCT terminal at
the dc equal level patch panel to a distortion analyzer,
distortion test set or a monitor teleprinter. Jack appearances for these items of equipment appear on the
miscellaneous/interbay jackfields of the dc test bays. If
teletype signals are not received at this point, a failure
in the local VFCT channel equipment is indicated. If
the VFCT passes the test signal, then the fault lies in
the voice frequency area or at the distant terminal (c
below).
(4) If the local VFCT equipment fails the test in
(3) above, request that station maintenance personnel
check the VFCT channel equipment serving the sub
scriber loop.
(5) The local Technical Controller should coordinate the transfer of the subscriber circuit to a spare
channel, if necessary with the distant station Technical Controller.
(6) Upon correction of the fault, the local Technical Controller should take action to return the sub
scriber circuit to its normal routing. To prevent unnecessary loss of traffic on the circuit, the patchcords
at both ends of the circuit should be removed simultaneously.
(7) Complete station records in accordance with
establishedprocedures.
c. Failure at Distant Terminal. If signals are detected during the test in b(3) above, and the local voice frequency channel equipment serving the VFCT check
good, a failure in the VFCT at the distant station is indicated. The local Technical Controller should do the
following:
(1) Contact the Technical Control Facility at the
distant VFCT terminal and request that he continue
the fault isolation procedure through the distant station. This procedure must be continued by all Technical Control Facilities involved with the circuit until
the fault has been isolated.
(2) Upon isolation of the fault at a distant station,
the responsible Technical Controller should coordinate
efforts to restore service to the subscriber. The temporary transfer of the circuit to a spare channel may be
required.
(3) Upon notification that the necessary repairs
have been made, the responsible Technical Controller
should assist the distant Technical Controller(s) in the
restoration of normal service to the subscriber.
(4) Complete station records in accordance with
established procedures.
d. Channel Degradation. The local Technical Control Facility is notified by a connected subscriber that
a teletypewriter machine has started to produce
garbled page copy. The report states that the error rate
is serious enough to render incoming messages unintelligible. The local Technical Controller should proceed
as follows:
(1) Subscriber Loop Check. The local Technical
Controller should patch a monitor teleprinter into a
MONITOR jack appearance of the complaining sub
scriber receive channel at the primary dc patch panel
to determine the quality of the signals passing through
to the subscriber loop. An alternate method is to patch
a distortion analyzer into the subscriber circuit at this
point to determine the type of distortion causing the
signal degradation. This information is most useful in
many instances in identifying the origin of a fault condition. Illustrations of normal and distorted teletype
signals are contained in the instruction manual for the
distortion analyzer.
(2) Range Setting Check. If the telegraph signals
are copied without garbling during the subscriber loop
check, the reported fault condition may be caused by
an improper range setting of the subscriber teletype
machine and this should be checked. If the copy is
garbled proceed to (3) below:
(a) Request the subscriber to standby for a test
transmisssion to evaluate the adjustment of the teletype machine.
(b) Patch a pattern generator output into the
LINE jack appearance of the subscribers receive circuit (transmit from the TCF to the subscriber) at the
primary dc patch panel. Transmit a Fox test message
to the subscriber station. The range control of the sub
scriber teletypewriter machine should be adjusted by
maintenance personnel to the midpoint of the range
over which perfect page copy is obtained.
(c) Upon correction of the fault, complete station records in accordance with established procedures.
(3) DLIU Check. If the monitor teleprinter produces garbled page copy when patched into the sub
scriber circuit, the Digital Line Interface Unit should
be checked for faulty operation. The Technical Con4-29
TM 11-5895-1012-10
troller should proceed as follows:
(a) Patch the monitor teleprinter into the MONITOR jack appearance of the subscriber’s receive circuit at the dc equal level patch panel. A defective
DLIU is indicated if perfect page copy is obtained at
this point. If not proceed to (4) below.
(b) Temporarily replace the normal DLIU with a
spare unit through patching operations.
(c) Request that local maintenance personnel repair the defective unit.
(d) When the repaired DLIU is returned to the
normal channel assignment, the Technical Controller
should remove any temporary patches which were
made to restore service to the subscriber.
(e) Complete station records in accordance with
established procedures.
(4) VFCT Channel Equipment Check. If the monitor teleprinter connected in (3)(a) above produces garbled page copy, the isolation procedure should continue following the procedure outlined in b above.
(5) Distant Terminal Check. If the degraded signal
is present in the voice frequency signal ((4) above) a defect in the VFCT equipment at a distant station is indicated and the fault isolation should continue following
the procedures outlined in c above.
4-37. Circuit Status
The duty supervisor of the Technical Control Facility
must know at all times the status of circuits and equipment removed from service because of failure or sub
standard performance. Positive action must be taken
to ensure that:
a. Notification is made when a circuit is determined
to be below acceptable quality standards and is to be
removed from service to restore it to an acceptable level. This notification should include the status of the
following actions:
(1) The appropriate control offices have been notified.
(2) That service has been restored using a spare
channel.
(3) That a spare channel is not available, and service to the user has been temporarily interrupted.
(4) That a spare channel is not available, and service is restored by preemption of a lower priority user.
The prerempted circuit must be identified by CCSD.
b. When user service must be interrupted, the Technical Controller coordinates with the local maintenance activity for initiation of immediate repair action.
c. Periodic progress reports on the restoration of
service will be provided to the duty supervisor so that
he can assure that the circuit is returned to service as
4-30
rapidly as possible.
4-38. Restoration
Individual circuits are restored in accordance with
their assigned restoration priority.
a. R&oration of service to users can basically be accomplished by repairing or replacing faulty equip
ment, rerouting the circuit around the disrupted segment of the circuit by using spare facilities, or by preempting a lower priority circuit to make a higher priority circuit good. In order to maintain continuity of
service for all users of the DCS, the correction of
equipment should be used in lieu of preempting another working circuit when the time required by each
method is nearly the same. Where trouble in a high
priority circuit has been localized to the transmission
media between two circuit end points and lower priori=
ty circuitry exist between these two points, the lowest
priority circuit(s) should be preempted if this will
restore the higher priority circuit in substantially less
time than the other methods of restoration.
b. To assist the Technical Controller in visualizing
the additional possible reroute paths available, block
diagrams will be prepared at each Technical Control
Facility for the area of interest, showing links between
connected stations and any appropriate extension
that would permit a reroute to be made. These diagrams should be maintained in a conspicuous location.
c. C-reference data will be prepared to permit
proper designation of facilities required during coordination for the r&oration of service. For example,
commercial numbers will be used to identify circuits to
commercial agencies. The cross-reference file will be
maintained in a position readily accessible to the Technical Controller on duty.
d. Within the DCS, Technical Controllers will, when
accomplishing control action& refer to circuits by
CCSD, and will refer to trunks by the DCS trunk
nator. In all cases, it is essential that Technical Controllers use equipment nomenclature and language
that is readily understood.
e. The primary responsibility for reroute action normally rests with the receiving Technical Control Facility. The appropriate control office will be notified
when reroute action cannot be accomplished.
f. When the trouble on the original path of a rerouted circuit has been cleared and tested, the Technical
Control Facility initiating the reroute will take action
to have the circuit returned to its original use and configuration. Also, this TCF will take action to return
the path, used for the reroute to its original use and
configuration.
TM 11-5895-1012-10
Section V.
MANCESTANDARDS AND TEST MEASUREMENTS
4-39. General
This section contains the DCS Technical Schedules,
which provide circuit performance parameters. Chapter 6 contains the associated test descriptions for test
measurements of DCS facilities, systems, or circuits.
In addition this section provides guidance for testing
DCS circuits to determine compliance with DCS Technical Schedule criteria and to determine circuit signaling performance.
parameters, unless specifically guaranteed by contract, are provided by the carrier on a “will-strive, nonguaranteed" basis; however, a circuit cannot be removed from service because of failure to meet these
other parameters unless the user reports unsatisfactory service and a nonguaranteed parameter is causing
the unsatisfactory service.
c. Leased circuits terminating in a military Technical Control Facility or Patch and Test. Facility at both
ends will be tested for the parameters in table 4-2 for
the type of service specified in the TSO. The common
carrier will meet guaranteed parameters and will be
requested to meet all other parameters. If the common
carrier declines to meet these additional parameters
and the user states that the circuit provides acceptable
service, the CCO will accept the circuit and identify all
out-of-tolerance parameters in the in-effect report.
d. Leased circuits terminating in a military TCF or
PTF at one end and a commercial test facility at the
other end will meet the parameters guaranteed by tariff or contract, as applicable. The TCF or PTF will request the carrier to test for all other parameters in
table 4-2 for the type of service specified in the TSO.
The CCO will identify in the ineffect report those parameters the carrier declines to test.
e. Commercial circuit parameters and identifiers
vary throughout the world and it is impractical to at
tempt to list all of them in this manual. Table 4-3 contains parameters and identifiers generally recognized
by the U.S. common carriers for conditioned circuits.
DCA areas will compile a listing of commercial circuit
parameters and identifiers used within their area of re-
Technical Schedules
4-40.
The DCS Technical Schedules are itemized listings of
all the common services and circuit parameters provided by the DCS. The DCS Technical Schedules apply to
all government-owned circuits within the DCS with
the exception of voice circuits provided over high frequency radio. Table 4-1 describes the type of service
provided by each circuit performance code. Tables 4-2
and 4-3 are a list of performance parameters required
by each parameter code. Table 4-4 is a list of leased
service performance parameters which common carriers generally provide. These tables are samples and
current procedural documents should be checked for
current requirements.
a Government-owned circuits are required to meet
each parameter for the type of service specified in the
TSO. Government-owned circuits unable to meet the
DCS parameters, even with optimum transmission adjustment, will meet the requirements specified by the
DCA.
b. Leased circuits will meet all parameters guarancontract, as applicable. U.S. common
tly guarantee frequency response and
envelope delay distortion parameters only. All other
Table 4-1. DCS Technical Schedules
4-31
TM 11-5895-1012-10
Table 4-1. DCS Technical Schedules-Continued
4-32
TM 11-5895-1012-10
Table 4-1. DCS Technical Schedules-Continued
Table 4-2. DCS Technical Schedules Circuit Parameters
4-33
TM 11-5895-1012-10
Table 4-2. DCS Technical Schedules Circuit Parameters - Continued
Table 4-3. DCS Technical Schedules
Circuit Parameters Z1, Z2, and Z3
4-34
TM 11-5895-1012-10
Table 4-3. DCS Technical Schedules Circuit Parameters Z1, Z2, and Z3 - Continued
4-35
TM 11-5895-1012-10
4
8
12
16 2 0
24
2 8 32 3 6
4 0 4 4 4 8 52 56
60 64
68 72
FREQUENCY (KHz)
NOTES:
1. ABOVE CURVE REPRESENTS ENVELOPE DELAY REQUIREMENTS. LIMITS ARE NOT
SPEClFlED BELOW 6 KHz.
2. IF THE ENTIRE CIRCUIT CONSISTS OF PROPERLY AMPLITUDE EQUALIZED TWISTED
PAIR CABLE, FROM WHICH ALL LOADING COILS AND BRIDGE TAPS HAVE BEEN
REMOVED, NO DELAY EQUALIZATION SHOULD BE REQUIRED. GIVEN THE CORRECT
FREQUENCY RESPONSE OVER THE RANGE OF .01 TO 50 KHz (NO DISCONTINUITIES
OR SHARP ROLLOFFS), ENVELOPE DELAY WILL NOT NORMALLY BE AN ITEM FOR
CONCERN ON CABLE PAIRS.
3. SHOULD THE CIRCUIT CONTAIN CARRIER FACILITIES, DELAY EQUALIZATION MUST
BE EMPLOYED SUCH THAT THE DELAY VERSUS FREQUENCY RESPONSE OF THE
CIRCUIT IS A SMOOTHLY AND CONTINUOUSLY INCREASING FUNCTION OF
FREQUENCY, WHICH FALLS WITHIN THE SHADED AREA OF THIS FIGURE.
EL3Z0046
Figure 4-10. Relative envelope delay vs frequency limits.
4-36
TM 11-5895-1012-10
Table 4-4. Commercial Technical Schedules
Note 1. Schedule 4A parameters are the same as C1 parameters
Note 2. Schedule 4B parameters are the same as C2 parameters
Note 3. Schedule 4C parameters are the same as C3 parameters
Nate 4. CCITT M.102 parameters are the same as C2 parameters, except that loss IS relative to 800 Hz instead of 1000 Hz
Note 5. DCS Technical schedules S1 and D1 compare to Commercial C2 Technical schedules for frequency response and envelope delay die
tortion.
Note 6 DCS Technical schedule S3 compares to Commercial C5 Technical schedules for frequency response and envelope delay distortion
4-41. Test Descriptions
Each Test Description (TD) includes the test arrangement, equipment configuration, and test procedure.
With the exception of those parameters which are not
applicable to all types of channels, each analog
parameter test description includes date for testing
the following types of channels: voice frequency chanchannels (0-50 kHz), 48 kHz channels
4-42. Digital Distortion Standards
The digital distortion standards contained in this paraan extract from other publications. It is
that some equipment currently used in the
will nut operate within these standards. Each
DCS facility using substandard equipment should
determine the technical reasons why the equipment
will not operate within established standards, and
determine a standard which the equipment can consistently meet. As a minimum, equipment will at least
meet the specifications contained in the technical or
manufacturer manual, where specified. Requests for
waivers from DCA performance standards will be sub
mitted through appropriate DCA regions to cognizant
DCA areas for approval, with an information copy to
appropriate O&M activities. Requests will contain the
technical justification for the waiver and the proposed
interim standard for the equipment. DCA areas will
review the technical data and proposed and where
appropriate grant the waiver. If necessary, full resolution of the waiver request will be carried to the Director, DCA.
a. Application. These standards apply to out-ofservice testing performed at the TCF patch bay. Tech
4-37
TM 11-5895-1012-10
nical Control Facilities should determine distortion
thresholds for the particular equipment and circuits
with their station and forward recommendations to
appropriate DCA field activities for concurrence, with
an information copy to appropriate Operation and
Maintenance activities. When distortion thresholds
are exceeded, the technical controller will initiate corrective action to remove the equipment from service.
For example, when the maximum output distortion allowed on a transmitter-distributor (out-of-service) is 1
percent, corrective action will be initiated when the
output distortion exceeds 4 percent. Corrective action
may include changing transmitter-distributors, repairing equipment on line, or using a spare circuit.
b. Equipment Capability. If the design capability of
equipment listed in subsequent paragraphs permits
operation at maximum distortion limits lower than
those specified, the maximum limits specified in the
technical manual or manufacturer handbook will
apply.
c. VFCT. With the transmit and receive terminals
connected back-to-back, sending and receiving loops
properly terminated, and all transmit tones at proper
levels, random undistorted signals will be keyed simultaneously into each sending loop at the maximum
modulation rate of the terminal design. The maximum
distortion measured in the receiving loops will not
exceed 4 percent total peak telegraph distortion at
modulation rates up to and including 75 baud.
d. Transmitting Equipment Output Distortion. The
output distortion (all types) of electromechanical, electronic, or composite transmitting devices (either
sequential or coincidental selection) will not exceed.
one percent.
e. Electromechanical Receiving Devices. Electromechanical receiving devices shall be capable of tolerating signal distortion as follows:
(1) Total peak distortion:45 percent.
(2) Bias distortion: 45 percent.
(3) End distortion: 45 percent.
(4) Cyclic distortion 22.5 percent.
f. Electronic-Input Receiving Devices. Receiving de
vices utilizing electronic input circuitry shall be
capable of tolerating signal distortion as follows:
(1) Total peak distortion: 49 percent.
(2) Bias distortion: 49 percent.
(3) End distortion: 49 percent.
(4) Cyclic distortion: 24.5 percent.
g. Electromechanical Polar Relays. Total distortion
introduced into the transmission facilities, attributable to the relay, shall be less than two percent.
h. Electronic Polar Relays. Total distortion intro
duced into transmission facilities, attributable to the
relay, shall be less than one percent.
i. Differential Phase Shift Keying (DPSK) Modems.
DPSK modems &all operate in accordance with per
4-38
formance requirements when the isochronous distortion of the input data is less than or equal to 10
percent measured at the data signaling rate of the
modem. The isochronous distortion of the output data
signal when measured at the operating data signaling
rate shall be less than four percent.
j. Digital Regenerative Repeaters.
(1) Synchronous repeater input will accept the following distortion limits and provide an output signal
with not more than three percent distortion, of which
not more than one-third (one percent) is bias:
(a) Total peak distortion: 49 percent.
(b) Bias distortion: 49 percent.
(C) Cyclic distortion: 49 percent.
(d) Fortuitous distortion: 49 percent.
(2) Start-stop repeater input will accept the
following distortion limits and provide an output
signal with not more than three percent distortion, or
which not more than one-third (one percent) is bias:
(a) Total peak distortion: 49 percent.
(b) Bias distortion: 49 percent.
(c) Cyclic distortion: 24.5 percent.
(d) Fortuitous distortion: 24.5 percent.
k. Punched Card Readers. Punched card readers
will produce not more than one percent distortion of
the signal element for electronic devices and 3.5
percent distortion for electromechanical devices, as
measured in relation to the theoretically correct unit
interval duration.
l. Card Punch. The card punch will operate without
error if the input distortion is less than the following:
(1) Total peak distortion: 49 percent.
(2) Bias distortion: 49 percent.
(3) End distortion: 49 percent.
(4) Cyclic distortion: 24.5 percent.
m. Magnetic Tape Readers. Total distortion attributable to the magnetic tape reader will not exceed one
percent at the output of the intermediate equipment.
n. Magnetic Tape Recorders. Magnetic tape recorders will operate without error if the input distortion is less than the following:
(1) Total peak distortion: 49 percent.
(2) Bias distortion: 49 percent.
(3) End distortion: 49 percent.
(4) Cyclic distortion: 24.5 percent.
o. Paper Tape Readers.
(1) Electromechanical Equipment. The total output distortion will not exceed one percent for the
standard 5-unit code character interval, and 3.5 percent for the standard 8-unit code character (ASCII).
(2) Equipment Incorporating Electronic Output
Circuitry. The total output distortion will not exceed
one percent.
p. Paper Tape Punches. Electromechanical paper
tape punches incorporating electronic serial input cir
TM 11-5895-1012-10
cuitry will operate without error if the input distortion
is less than the following:
(1) Total peak distortion: 49 percent.
(2) Bias distortion: 49 percent.
(3) End distortion: 24.5 percent.
q. Link Encryption Equipment. Link encryption
equipment will accept distortion (all types) up to 49
percent and provide an output signal with not more
than one percent distortion.
4-43. Conduct of Tests
The Circuit Control Office designated in the TSO is responsible for circuit activation, to include the scheduling, supervising, and reporting of circuit tests. The
CCO will ensure that each segment of the circuit is
properly aligned and tested against the applicable
standards prior to conducting end-to-end testing.
Intermediate TCF's on the circuit path will be
responsive to directions issued by the CCO.
a. End-to-end testing, as used in this technical
manual refer to the point nearest the user terminals at
each end of the circuit where the capability exists to
performance required testing. In many cases, this will be
the serving TCF or PTF. In some cases, end-to-end
testing may be performed at the user terminal. Technical Control Facilities will determine the point at
which required end-to-end test measurements are
made for each circuit. When tail segments between the
TCF and the user cannot be readily tested on a scheduled basis, arrangements will be made to test the user
loop from the TCF to determine loop characteristics.
Data obtained from this test will be retained in the
TCF for reference during subsequent Quality Control
testing or troubleshooting.
b. Leased circuits are considered to be one segment,
regardless of the number of breakout points in the circuit. Common carriers are responsible for providing required signals at the point where government and
commercial facilities interface.
4-44. Test Reporting
a. The CCO will submit an In-Effect Report or
Exception Report as specified in established
procedures. The following instructions pertain to sub
mission of the reports:
(1) Subsequent to submitting an In-Effect Report,
the Circuit Parameter Test Report, DD Form 1697 will
be forwarded in accordance with existing directives to
the DCA activity that issued the TSO and the cognizant DCA region.
(2) When an exception report must be submitted,
the CCO will include in the message, as a part of the
statement of the problem, an extract of the appropriate portion of the Circuit Parameter Test Report.
These extracts will include identification of the test
that failed to meet specifications, specific measurements obtained and comments, e.g., change in audio
frequency + 20 Hz, measurement made at station
Alpha from station Bravo (include further comments
on nature of trouble and estimated time to repair).
b. When it is determined as a result of out-of-service
Quality Control testing that circuit or equipment
parameters cannot be brought within test and acceptance specifications, the CCO or affected Technical
Control Facility will forward the following information to appropriate DCA and operation and maintenance elements. DCA, in cooperation with lateral
O&M elements, will ensure that required technical
assistance is provided to return the circuit or equipment test and acceptance specifications.
(1) Identification of circuit or equipment.
(2) Test and acceptance measurements for those
parameters failing to meet specifications.
(3) Out-of-service Quality Control test measure
ments for those parameters failing to meet specifications.
(4) Remarks.
4-45. Recording Test Results
a. DD Form 1697 (Circuit Parameter Test Report)
will be used to record the results of testing performed
for initial acceptance of service and for each reconfiguration of the circuit. A copy of this test report
will be filed with the corresponding TSO at the
cognizant DCA region or area and maintained in the
Technical Control Facility files. DD Form 1697 may be
overprinted as required by DCS operating elements.
b. DD Form 1697 will not be forwarded to DCA or
operation and maintenance elements when scheduled
or unscheduled quality control testing is performed
unless tasked to do so for specific circuits and for
specific periods of time. However, a record of quality
control tests and test results will be maintained in the
Technical Control Facility files. Local forms may be
used provided they contain all information required
for DD Form 1697.
Section VI. CIRCUIT PERFORMANCE AND QUALITY CONTROL TESTING
4-46. Introduction
by detecting and correcting adverse trends before the
a. Effective worldwide service to all users of the
user service is affected.
DCS requires each segment of the system to be opb. Quality control is that function by which pererated and maintained at its specified operating level.
formance is measured and the results are then comThe concept of quality control and performance
pared against established standards. Optimum
monitoring is to prevent interruption to user service
performance can be achieved and maintained by
4-39
TM 11-5895-1012-10
thorough testing and analysis of test results. An effective quality control program consists of scheduling
prescribed tests, measuring specific parameters, comparing recorded measurements against applicable
standards, trend analysis and directing corrective actions where indicated.
4-47. Quality Control of Governmentowned Circuits
a. In-Service Quality Control Testing. In-service
quality control testing is performed regularly on all
active circuits within the Technical Control Facility.
Measurements are made using high impedance bridging to prevent interruption of user service. Normal
user traffic signals, telephone supervisory parameters
which can be measured without interruption of service
and then compared to levels normally found at the
transmission level point of the circuit under test.
(1) The technical controller analyzes the test results to determine if corrective action is required to
bring the circuit within system standards or the
original circuit acceptance parameters. When required, corrective action can be accomplished by
rerouting the circuit, equipment substitution on the
normal path, or, when neither is possible, obtaining a
user release of service in order to take the circuit out
of-service for maintenance action.
(2) If the user does not want to release the circuit
because of traffic load or mission requirements and
states that the degraded circuit is providing satisfactory service, the technical controller will make arrangements with the user for release of the circuit as
soon as traffic conditions or mission requirements
permit.
(3) Appropriate maintenance elements and connected TCF's or PTF’s will be advised of the substandard condition of the circuit and of the projected downtime.
b. Out-of-Service Quality Control Testing. It is the
responsibility of the TCF designated as Circuit Control
Office to schedule out-of-service quality control testing on all circuits over which responsibility has been
assigned. Periodic out-of-service testing permits endto-end realignment of circuits to meet applicable DCS
circuit parameters. Out-of-service testing usually
requires the user to release the circuit for a specified
amount of time. Where at all possible a reroute will be
provided depending upon the circuit priority.
c. Communications Equipment. Scheduled quality
control testing of all communications equipment sup
porting the DCS, including spares, is required. Communications equipment may be located in other sections of the DCS Station; i.e. radio and carrier,
automatic switching centers, communications centers,
or within the TCF itself. In most cases, there is a Patch
and Test Facility associated with the section involved.
4-40
All quality control testing of communications equip
ment will be conducted with the knowledge and permission of the TCF supervisor on duty. Operational
equipment will be tested off-line after the completion
of regularly scheduled maintenance and in conjunction
with the appropriate maintenance personnel. Where
possible, equipment will be tested under maximum
loading, such as all VFCT equipment channels being
keyed with test messages. A review of trend analysis
should be made by TFC and maintenance personnel
prior to the test. This will identify channels that have
had most of the outages and degree of maintenance adjustments since the last scheduled test. This analysis
may show the possibility of deteriorating components
in the equipment and that this test period may require
a closer examination of the item of equipment than is
normally required during routing testing.
4-48.
The basic requirement for quality control testing of
leased communications circuits is identical to that required on Government owned circuits, with the following exceptions:
a In-Service Quality Control Testing. When it is
determined through in-service testing that a circuit
does not meet parameters contracted for in the Communications Service Authorization (CSA), one of the
following actions must be initiated:
(1) If the user states the circuit is not providing
satisfactory service, the circuit will be logged out-ofservice with the commercial carrier for immediate
corrective action.
(2) If the user states that the circuit is providing
satisfactory service and the commercial carrier cannot
provide immediate corrective action or reroute, corrective action will be scheduled for a time mutually
agreeable to the user and the carrier.
b. Out-of-Service Quality Control Testing. The Circuit Control Office will coordinate quality control test
schedules with commercial carriers to ensure that the
carriers will have personnel and *test equipment available to participate in quality control tests and initiate
corrective actions if the circuit does not meet
parameters contracted for in the CSA.
4-49. Quality Control
a. In-Service Test Schedules. Tests and frequency of
tests shown in table 4-5 are considered the minimum
required. Detailed schedules will be such that these
minimum requirements are satisfied. The TCF may increase the frequency of testing as necessary to ensure
required operations. Test requirements may be satisfied by use of automatic sensing equipment which
measure circuit parameters and provides a record
copy of readings or alarms which sound when present
TM 11-5895-1012-10
program will be used as the criteria for developing the
exceeded.
quality control testing schedule. However, if deemed
rvice Test Schedules. Out-of-service,
necessary, the frequency of testing may be increased
end-to-end quality control tests, will be scheduled by
by the TCF to ensure optimum operating conditions.
the responsible CCO. The tests and frequency of tests
Quality control testing of equipment ensures that the
shown in table 4-5 are considered the minimum
equipment meets the technical specifications conessential. Selected out-of-service, end-to-end quality
tained in the applicable technical manuals.
control tests, as determined by the TCF, are required
d. Analysis of Test Results. Analysis of test results
after a transmission media failure, when equipment or
and of equipment failures might indicate a need to
lines are suspected of being faulty, when directed by
revise test schedules. If a particular type of equipment
the appropriate DOCC or operation and maintenance
or circuit is causing little or no outage between quality
element, or when deemed necessary by the TCF to
control tests, an increase in the time interval between
ensure optimum operation.
scheduled tests might be appropriate. Conversely, if
c. Communications equipment Test Schedules.
many outages are incurred or frequent adjustments
Quality control testing of operational and spare equip
are required on the equipment or circuit, a decrease in
ment appearing on the TCF of PTF patch panels will
the time interval between scheduled tests might be apbe performed on a scheduled basis. The time interval
propriate.
currently used by the operation and maintenance activities in their established preventive maintenance
Table 4-5. Circuit Quality Control Schedule
Legend: 72-Every 72 Hours: Q-Quarterly; S-Semiannual: A-Annual
Note 1. V2 parameters will be used for out-of-service testing of spare unconditioned VF channels and circuits. unless otherwise specified.
Note 2. Certain voice circuits utilize tone-on-while-idle supervisory signaling and will normally have a signal. either speech or tone. present
Measurements will be made at the monitor jack AS false rings will be caused by breaking the supervisory tone The normal speech level is - 12
VU at the 0 dBm TLP. The normal tone-on-while-idle signal level IS - 20 dBm0
Note 3 Testing of channels under the PMP satisfies this requirement
Note 4. Normal day-today technical control actions satisfy in-service test requirements for active dc circuits Spare dc circuits will be tested
for total peak distortion at least once every 72 hours. use of a spare dc circuit for reroute or establishing an on-call circuit satisfies this requirement
4-41
TM 11-5895-1012-10
Table 4-6. Noise Power Conversion
4-42
TM 11-5895-1012-10
Table 4-6. Noise Power Conversion - Continued
4-50. Performance Monitoring
The DCS Performance Monitoring Program encompasses monitoring the operation of the DCS transmission links using critical operating parameters as performance indicators, and the analysis of the information received to develop performance trends. Each
DCS Technical Control Facility will participate in this
program in accordance with established guidelines and
directives.
4-51. Trend Analysis
Analysis of quality control data will be performed by
the Technical Control Facility on as near a real-time
basis as possible to identify degrading trends.
a. In-service quality control tests are the best tools
to identify degradation because measurements can be
taken and recorded without interrupting the user.
Measurements of each quality control test are compared with the measurements taken in the past. If a
definite change is noted, but the circuit is still providing satisfactory user service, it should be flagged as a
special interest circuit. One substandard measurement
does not constitute a trend. If, after several measurements are taken, further changes are indicated, a degrading trend is evident and corrective action should
beinitiated.
b. Trend analysis is not limited to quality control
measurements. Trends can be detected from the
number of outages over a given period of time. The
minimum number of outages per circuit, of course, is
not definable. The length of outage should not be considered in this analysis.
c. Trend analysis can be expanded to determine
whether large number of outages are occurriug in the
same time frame. This analysis should be performed if
large numbers of outages cannot be reduced after repeated attempts to locate and correct the deficiency.
d. To simplify the analysis effort, data may be
transposed from worksheets to a line or bar graph or
some other management tool, such as a computer runoff to give the history and present quality of a given
circuit or channel at a glance. Comparison with all
other channels of a particular group will indicate the
general quality of the group.
4-43
TM 11-5895-1012-10
e. Figure 4-11 through 4-13 are examples of
typical graphs that may be used for trend analysis.
4-52. Excessive Signal Levels
Frequently, excessive signal levels are introduced into
the DCS from the user equipment. Excessive signal levels
from just a small number of users can cause crosstalk
across the baseboard of an entire system. Whenever
excessive signal levels are detected, as a result of inservice quality control testing or as a result of a user
complaint, immediate action will be initiated by the
technical controller to locate the source. The serving
TCF will immediately notify the violating user, direct
his attention to the provisions of established directives, and request that immediate action be taken to
correct the deficiency. If the user continues to violate
signal level limits, the serving TCF will deny service to
the user until proper signal levels are
by the
user. Actions of this nature will be properly documented and immediately reported to the appropriate
Docc and operation and maintenance activities.
Denial of service for this reason should be done
judiciously and then only with approval of the
Technical Control Facility shift supervisor. As a rule
of thumb, the following criteria may be applied:
a. If the signal level is within 3 dB of the correct
level, the serving TCF should initiate normal coordination to correct the level.
b. If the signal level is between 3 dB and 6 dB above
the correct level, the user must correct the level within
15 minutes or the TCF will deny service.
c. If the signal level is more than 6 dB above the correct level, the TCF will immediately deny service until
the user provides the correct level.
Figure 4-11. Sample distortion trend analysis chart.
Figure 4-12. Sample noise level trend analysis chart.
4-44
EL3Z0048
TM 11-5895-1012-10
Figure 4-13. Sample number of outages trend analysis chart.
4-53. Improper Termination of Circuits
Circuits improperly terminated and user terminals
modified without appropriate Technical Service Order
action will be denied access to the DCS, in accordance
with the procedures in paragraph 4-52. Access will be
denied the violating user until the terminations are in
accordance with the TSO. It is the responsibility of the
user to provide proper interface or terminations for
circuits entering the DCS.
4-54. Quality Control and Performance
Monitoring Management
monitoring is the
responsibility of each technical controller within the
. The technical control shift supervisor is responsible for ensuring that scheduled testing is performed.
The shift supervisor will advise the technical control
chief of any problem areas, and of any circuits of sys-
tolerance, and coordination with commercial carriers
when leased circuits are out of tolerance.
b. The teat equipment on site is the responsibility of
the Military Department operating the DCS Station.
When an item of test equipment is inoperative or
turned in for recalibration, and a like piece of equip
ment is not available, the test equipment should he declared “mission essential” and an attempt made to
obtain a replacement so that fault isolation, quality
control testing, and performance monitoring functions
are not impaired.
c. The DCS Station will prepare quality control and
performance monitoring checklists that enable any
technical controller to test any equipment, circuit, or
system within the facility.
4-55. Quality Control Tests
Typical Quality Control Test procedures, with test setup diagrams are contained in chapter 6. The test
procedures are general in nature and do not specify
test equipment by commercial type number of military
nomenclature. Test equipment is referred to in a
generic sense, i.e., level meter, signal source
(generator), phase jitter meter, etc. Substitution of the
specific item of test equipment on site, should
any technical controller to perform the specified Quality Control tests.
4-45
TM 11-5895-1012-10
Section VII. IMPLEMENTATION OF COMMUNICATIONS SERVICES REQUIREMENTS
AND INSTATION TESTING
4-56. Telecommunications Service Orders (TSO's)
The basic circuit design information for all new or
changed circuits is provided in the DCA Telecommunications Service Orders (TSO's). The TSO is the authorization for DCA Headquarters of a DCA area to
activate, change, or deactivate circuits or trunks, to
amend previously issued TSO’s, and to effect administrative changes. The TSO gives the following information:
a. Issuing office.
b. The year it is issued.
c. TSO serial number.
d. Circuit identification.
e. The sequential action being taken on the circuit.
4-57. TCF Responsibilities
a. The many variations found in the configurations
of DCS Station Technical Control Facilities prevent
the development of precise procedures for the installation, alignment, and testing of circuits which would
apply to all types of circuits and to every DCS Station.
However, there are certain functional steps in activating circuits which are common to all stations. Upon receipt of a TSO, the following steps are necessary to
install, align, and test the circuit.
(1) Administrative processing and logging of
receipt of the TSO.
(2) Preparation of the detailed in-station layout
designating specific cross-connects and specific equipment to be utilized as required by the TSO.
(3) Preparation of work order, or instructions, to
section(s) or personnel responsible for performing instation wiring.
(4) Performance of in-station wiring check by
Technical Control Facility personnel on in-station circuitry and associated transmission links in conjunction
with adjacent TCF’s.
(5) Notification to appropriate control offices that
in-station and adjacent link tests are complete and
meet required criteria.
(6) Performance of circuit alignment tests by TCF
personnel on in-station circuitry and associated transmission links in conjunction with adjacent TCF.
(7) Participation in end-to-end testing and directed by the appropriate control office.
(6) Administrative recording and reporting of
action required or completed in conjunction with the
installation. Managerial procedures for accomplishing
the above functions are left to the discretion of the
individual station. However, close coordination is important between the section preparing the in-station
4-46
wiring layout and the Technical Controller performing the in-station tests to prevent errors in the circuit
installation and to ensure that required technical
parameters have been met.
b. Upon completion of the in-station installation,
the Technical Controller is responsible for ensuring
proper alignment of the in-station portion of the circuit as well as the adjacent link(s). Continuity and
transmission level adjustments on the in-station
installation will be performed first. When the in-station portion of the circuit is properly installed and adjusted, the input and output levels on all external
transmission channels assigned to the circuit must he
adjusted to the proper value. Additional checks as required to ensure proper functioning of conditioning
and signaling equipment will be made. When the
internal and external alignment and checks are complete, an overall recheck of the complete installation
will be made. In the specific cases where a PTF is located between the Technical Control Facility and the
user, the TCF is responsible for ensuring that the
transmission levels, signaling and conditioning of the
circuit are properly adjusted between the user and the
PTF.
c. Each circuit installed in the DCS will be tested in
accordance with the criteria specified in the DCS Technical Schedule for the type of circuit in the TSO. Upon
notification from all intermediate TCF's that in-station and adjacent segment tests are complete, the
Tech&al Control Facility designated as Circuit Control Office will initiate end-to-end tests of the circuit.
Each of the specific tests are required to ensure compliance with the DCS circuit technical schedule
parameters. Refer to applicable DCA documentation
to determine the DCS Technical Schedule and Circuit
Parameters for the circuit that has been installed.
d. The Technical Control Facilities concerned will
immediately notify the CCO or the ICO, when, for any
reason, delays are encountered or anticipated in
activation of circuits. The notification will contain de
tailed information on reasons for delay or inability to
activate circuits. Pertinent recommendations on
methods of providing service should also be included.
This information may be used by the CCO in preparation of an exception report.
e. Deactivation of circuits will be accomplished
after coordination with all concerned and records will
be retained in an inactive or “dead” file for 6 months
before destruction or disposition in accordance with
establishedrequirements.
f. Completion of activation records and reports is
the responsibility of the Technical Controller.
TM 11-5895-1012-10
4-58. Procedures for Changing and
Building Circuits
a
are:
, actions necessary to change a circuit
(1) Patch around the in-house portion of the existing circuit, or terminate the circuit legs on the line side
of the patch panels with 600-ohm terminating plugs.
(2) Remove from the universal conditioning
equipment shelf the modules of the string to be
(3) Remove cross-connects and rewire the IDF in
the conditioning equipment bay to form the desired
string.
(4) Change cross-connections on the voice frequency, combined distribution frame (CDF) to obtain
the desired jack appearances and multiples, cable, or
VFCT assignments necessary.
(5) Replace the conditioning modules.
(6) Perform the necessary in-house quality control
checks (refer to chapter 6).
(7) Remove patches or plugs installed in (1) above.
(8) Perform the necessary station-to-station tests
(refer to chapter 6).
b. Generally, actions necessary to build a new circuit are:
(1) Form the desired conditioning equipment
string by cross-connecting at the IDF above the bay.
(2) Cross-connect at the VF CDF to connect the
string to the desired patch panels (insert dummy plugs
in all line jacks if the patch panels are already wired to
a multiplex or channel VFCT, or cable pair).
(3) Plug in all conditioning equipment modules.
(4) Perform the necessary in-house quality control
checks (refer to chapter 6).
(5) Cross-connect the patch panels to the appropriate multiplex or VFCT channel or cable pair at the
VF CDF (or remove dummy plugs if previously wired).(6) Perform the necessary out-of-service stationto-station quality control tests (refer to chapter 6).
4-59. Sample Circuit Building Procedure
The sample process for building voice frequency circuit configuration figure 4-14 is as follows:
a Voice Frequency Circuit Connections. Refer to
the cut-sheet table 4-7 and figure 4-14 which illustrate the following cross connection procedure.
(1) Connect the Equ Out (Drop) side of the receive
equal level patch panel circuit terminated on block
H17J, row 1, pins 3 and 4 to the signaling frequency
(SF) unit receive input (line aide) terminated at bay 4.1
on block TB3, row 1 pins E and F by cross-connecting
black H17J, row 1, pins 3 and 4 to block V9F, row 2,
pins 1 and 2 respectively and at bay 4.1, TB3, row 1,
pins E and F to TB9, row 1, pins E and F respectively.
(2) Connect the Equ In (Drop) side of the transmit
equal level patch panel circuit terminated on block
H17K, row 1, pins 3 and 4 to the DF unit transmit output (line side) terminated at bay 4.1 on block TB3, row
1 pins C and D by cross-connecting block H17K, row 1,
pins 3 and 4 to block V9F, row 1, pins 3 and 4
respectively and at bay 4.1, TB3, row 1 pins C and D to
TB9, row 1, pins C and D respectively.
(3) Connect the SF unit receive output (Drop) side
terminated at bay 4.1 on TB3, row 1, pins H and J to
the amplifier (Al) input terminated at bay 4.1 on TB3,
row 2, pins A and B by cross-connecting TB3, row 1,
pins H and J to TB3, row 2, pins A and B respectively.
(4) Connect the SF unit transmit input (Drop) side
terminated on TB3, row 1, pins A and B to the Pad
(P2) output terminated on TB3, row 3, pins H and 9 by
cross-connecting TB3, row 1 pins A and B to TB3, row
3, pins H and J respectively.
(5) Connect the SF unit E&M leads terminated at
bay 4.1 on TB3, row 1, pins K and L to the ringdown
converter (RDC) E&M leads terminated at bay 4.1,
TB3, row 1, pins K and L to TB3, row 6, pins K and L
respectively.
(6) Connect the amplifier (Al) output terminated
at hay 4.1 on TB3, row 2, pins C and D to the pad (P1)
input terminated at bay 4.1 on TB3, row 3, pins A and
B by cross-connecting at bay 4.1, TB3, row 2, pins C
and D to TB3, row 3, pins A and B respectively.
(7) Connect the pad (P2) input terminated at hay
4.1 on TB3, row 3, pins E and F to the amplifier (A2)
output terminated at bay 4.1 on TB3, row 2, pins H
and J by cross-connecting at bay 4.1, TB3, row 3, pins
E and F to TB3, row 2, pins H and J respectively.
(8) Connect the pad (P1) output terminated at hay
4.1 on TB3, row 3, pins C and D to the echo suppressor
receive input (line) terminated at bay 4.1 on TB3, row
4, pins E and F by cross-connecting at bay 4.1, TB3
row 3, pins C and D to TB3, row 4, pins E and F respectively .
(9) Connect the amplifier (A2) input terminated at
bay 4.1 on TB3, row 2, pins E and F to the echo suppressor transmit output terminated at bay 4.1, TB3,
row 4, pins C and D by cross-connecting at bay 4.1 on
TB3, row 2, pins E and F to row 4, pins C and D respectively .
(10) Connect the echo suppressor receive output
terminated at bay 4.1 on TB3, row 4, pins H and J to
the 2/4 wire terminating set receive input terminated
at bay 4.1 on TB3, row 5, pins A and B by cross-connecting at bay 4.1, TB3, row 4, pins H and J to row 5,
pins A and B respectively.
(11) Connect the echo suppressor transmit input
terminated at bay 4.1 on TB3, row 4, pins A and B to
the 2/4 wire terminating set transmit output minated at bay 4.1, on TB3, row 5, pins C and D by crossconnecting at bay 4.1 on TB3, row 4, pins A and B to
row 5, pins C and D respectively.
(12) Connect the 2/4 -wire terminating set’s 2 wire
4-47
TM 11-5895-1012-10
line terminated at bay 4.1 on TB3, row 5, pins K and L
to the E&M/25 Hz ring down converter's Send In (T1,
R1) line terminated at bay 4.1 on TB3. row 6, pins A
and B by cross-connecting at buy 4.1, TB3, row 5, pins
K and L, to TB3, row 6, pins A and B respectively.
(13) Connect the 2/4 wire terminating set terminated at bay 4.1 on block TB3, row 5, pins E and F to
the VF primary patch panel terminated on block
H13K, row 1, pins 3 and 4 by cross-connecting at bay
4.1, TB3, row 5, pins 3 and F to TB9, row 5, pins E and
F respectively and block V9F, row 10, pins 1 and 2 to
block H13K, row 1, pins 3 and 4 respectively.
(14) Connect the E&M/25 Hz ringdown converter
Receive In line terminated at bay 4.1 on TB3, row 6,
pins C and D to the VF primary patch panel equipment
side (T1, R1) terminated on block H13K, row 1, pins 3
and 4 by cross-connecting at bay 4.1 TB3, row 6, pins
C and D to TB9, row 6, pins C and D respectively and
block H13K, row 1, pins 3 and 4 to block V9F, row 11,
pins 3 and 4 respectively.
b. Voice Frequency Level Adjustments. The InStation test will be run before connecting to the multiplexer equipment. Adjust levels from the equal level
patch panel to the primary patch panel as follows:
(1) At the equal level patch panel, the receive and
transmit levels will be at 0 dBm.
(2) The SF-2600 has approximately 0 dB insertion loss and will not affect the circuit level.
(3) Adjust amplifiers 1 and 2 for a 12 dB gain and
pads 1 and 2 for an 8 dB loss to compensate for the 4
dB insertion loss of the 4 wire termination set and allow an operation level of 0 dBm at the voice frequency
(4) The E&M/25 Hz converter and echo su
has approximately 0 dB insertion loss and will not affect the circuit levels.
c. In-Station Testing After the correct circuit levels
have been obtained, perform the in-station test procedures contained in chapter 6. To use a test on a 2 wire
circuit, use the same two-wire circuit for both transmit
and receive tests and omit the terminating resistor
when necessary.
d. Multiplexer Equipment Connections. Refer to
the sample cutsheet (table 4-7) and cross-connect as
follows:
(1) Connect the multiplexer receive circuit terminated on block V32K, row 1, pins 3 and 4 to the equal
level patch panel DEM IN (line) terminated on block
H17J, row 1, pins 1 and 2 by cross-connecting block
V32K, row 1, pins 3 and 4 to block H17J, row 1, pins 1
and 2 respectively.
(2) Connect the multiplexer transmit circuit
terminated on block V32K, row 1, pins 1 and 2 to the
equal level patch panel MOD OUT (Line) terminated
on block H17K, row 1, pins 1 and 2 by cross-connecting block V32K, row 1, pins 1 and 2 to block H17J,
row 1, pins 1 and 2.
c. Final Testing. Perform the out-of-service quality
control (station-to-station) testing contained in chap
ter 6. If the circuit checks out in accordance with the
testing and conforms to established parameters, then
report the circuit ready for operation in accordance
with established procedures.
Table 4-7. Sample cutsheet for 2-wire voice circuit t (25 Hz signaling and echo suppressor control)
4-48
TM 11-5895-1012-10
Table 4-7. Sample cutsheet for 2-wire voice circuit (25 Hz signaling and echo suppressor control) - Continued
Section VIII. ACCEPTABILITY OF NEW EQUIPMENT
4-60. General
There is a need for continuing improvement in transmission quality. Therefore, integration of new equip
ment into the DCS is accomplished in some areas of
the world every week. Technical and operational compatibility is always an important consideration.
4-61. technical Control Facility Responsibilities
a. The Technical Control Facility chief will:
(1) Supervise an evaluation test of the equipment
to be cutover before it is placed on-line for DCS traffic. This will include as a minimum, but not be limited
to, the following
(a) All quality control tests that are normally
performed on the subject item of equipment.
(6) Back-to-back and looped tests will ‘be performed as appropriate.
(c) Preparation of quality control records for the
new equipment to include posting of all test information. A copy of the initial tests will be provided the appropriate DCA area or region.
(2) Coordinate with appropriate control offices
and other DCS Stations, as required, the addition of
the new equipment into the system.
(3) Supervise the cut-over of all circuits to the new
equipment.
(4) Supervise the testing of all circuits that require conditioning to ensure that the proper transmission parameters are maintained.
b. Special attention must be given to protection of
service to users that have control, error detection, and
alarm devices on their circuits. Full coordination must
be made prior to any cut-over or testing to maintain
operations without damage to communications equip
ment.
c. Where service must be interrupted for cut-over of
new equipment, the established procedures must be
followed. Cut-over plans will be submitted to the appropriate DOCC in sufficient time to review and coordinate the plan.
4-62. Test and Acceptance
Acceptability of new systems and subsystems usually
require the services of test and acceptance (T&A)
teams. In some cases, one terminal and sometimes
both, may terminate in a facility where Technical Control Facility personnel are not assigned, but where the
facility is aligned as a system or subsystem reporting
responsibility of a Technical Control Facility. In all
cases it is imperative that personnel of that Technical
Control Facility be members of the T&A teams accept
4-49
TM 11-5895-1012-10
Sample voice frequency circuit configuration connection diagram (sheet 1 of 3).
Figure 4-141. Sample
Sample voice frequency circuit configuration connection diagram (sheet 2 of 3)
Figure 4-142. Sample
4-50
TM 11-5895-1012-10
Figure 4-143. Sample voice frequency circuit configuration diagram (sheet 3 of 3).
4-51
TM 11-5895-1012-10
4-52
TM 11-5895-1012-10
CHAPTER 5
STATION MAINTENANCE
5-1.
Operator's preventive maintenance is the systematic
care, servicing, and inspection of equipment to prevent the occurence of trouble, to reduce downtime,
and to assure that the equipment is serviceable.
a Systematic Care. The procedures given in paragraphs 5-3, 6-4, 5-5, and 5-6 cover routine systematic care and cleaning essential to proper upkeep
and operation of the equipment. Item numbers indicate the sequence of minimum inspection requirements.
b. Preventive Maintenance Checks and Services.
The preventive maintenance checks and services
charts (para 5-3 through 5-5) outline functions to be
performed at specific intervals. These checks and services are designed to maintain Army Equipment in a
combat-serviceable condition; that is, in good general
(physical) condition and in good operating condition.
The charts indicate what to check, how to check, and
the normal conditions. Defects discovered during
operation of the technical control facility will be noted
far future correction, to be made as soon as equipment
can be freed from service. Operation will be stopped
immediately if a deficiency is noted which would damage the equipment. If the defect cannot be remedied by
the operator, higher category of maintenance or repair
is required.
5-3.
Operator
Daily
Checks
5-4.
Operator
Weekly
Preventive
Preventive
Maintenance
Maintenance
5-2. Preventive Maintenance Checks and
services Periods
Preventive maintenance checks and services of the
technical control facility are required daily, weekly
and quarterly.
a Paragraph 5-3 specifies the checks and services
that must be performed every day that the equipment
is used, and under the special conditions listed below:
(1) When the equipment is initially installed.
(2) When the equipment is reinstalled after
removal for any reason.
(3) At least once a week, if the equipment is maintained in standby condition.
b. Paragraph 5-4 specifies additional checks and
services that must be performed on a weekly basis.
c. Paragraph 5-5 specifies other checks and services
that must be performed on a quarterly basis.
Checks
and
and
Services
Services
5-1
TM 11-5895-1012-10
5-5. Operator Quarterly Preventive Maintenance Checks and Services
5-6. Cleaning
a. Materials Required. The following materials are
required for cleaning the equipment in the technical
control facility:
(1) Trichloroethane.
(2) Soft, lint-free cloth.
(3) Liquid detergent.
(4) Nylon bristle brush.
WARNING
The fumes of trichloroethane are toxic. Provide thorough ventilation whenever used. DC
NOT use near an open flame. Trichloroethane
is not flammable, but exposure of the fumes
to an open flame or hot metal surface converts them to a highly toxic phosgene gas. Inhalation of this gas could result in serious injury or death.
b. Methods. Perform the following procedures to
5-2
clean the equipment in the technical control facility:
(1) Inspect exterior surfaces of the equipment for
dust, dirt, grease and fungus.
(2) Remove the dust and loose dirt with a soft,
clean cloth.
(3) Remove grease, fungus, and ground-in dirt
from metal parts with a cloth dampened (not wet) with
trichloroethane.
(4) Remove dust or dirt from plugs and jacks with
a soft brush.
CAUTION
Do not press on the METER FACE when
cleaning. Damage to the equipment may result.
(5) Clean the front panel, meter face, and controls
of the equipment using a soft, clean cloth. If necessary,
dampen the cloth with water or mild detergent for
more effective cleaning.
TM 11-5895-1012-10
CHAPTER 6
TEST PROCEDURES
6-1. Introduction
a. Scope of Testing. Test procedures in this chapter
cover station to station (quality control) and in-station
(maintenance) testing. However, testing at a particular
facility should not be limited to the testing described
by this chapter nor should all facilities necessarily
perform all the tests described in this chapter. The
number and types of tests performed at a specific technical control facility depends on the type of service
provided by the facility and on the technical services
schedule for that facility. The tests in this chapter are
primarily intended for checking multiplex voice-channel breakout to multiplex voice-channel breakout links
with single or multiple hop paths.
b. Quality Control Tests. Quality control or station
to station tests should be performed regularly as specified in chapter 4. These tests are used for evaluation of
the performance of a circuit and in end-to-end circuit
fault isolation.
c. Maintenance Tests. Maintenance or in-station
tests should be performed prior to putting a circuit
into operation if the circuit has just been built or repaired. They are also used in troubleshooting station
equipment.
6-2. Description of Test Equipment
The test equipment described below is required to
perform the tests specified by this chapter. The
descriptions given are of a general nature since the
test equipment at each facility varies with the functions of that facility and the services it provides.
a. Noise Measuring Test Set. The noise measuring
test set is used to measure noise and signal levels to
-85 dbm. It has a frequency range of 50 to 5000 Hz
and may be balanced for either 600 or 900 ohms
impedance. If a Universal Transmission Measuring
System is available, it may be used in place of the noise
measuring test set.
b. Transmission Test Set. The transmission test set
a test oscillator, an attenuator, a matching
and a level meter. It has the following
performance characteristics:
(1) Minimum frequency range of 20 Hz to PO KHz
(2) Frequency-Amplitude response of less than 0.5
db variation over 20 Hz to 10 KHz into a matching
resistive load.
(3) Minimum output level range of + 5 to -30
dbm.
(4) Output impedance of 600 to 900 ohms,
balanced.
(5) Input of level meter is 600 or 900 ohms.
c. Envelope Delay Test Set. The envelope delay test
set consists of a transmitter and receiver. It measures
signal delay and amplitude versus frequency. It has
the following performance characteristics:
(1) Carrier frequency adjustable from 200 Hz to
600 Hz.
(2) Modulation frequencies of 25, 83 1/3, and 250
Hz.
(3) Amplitude accuracy of ± 0.5 db.
(4) Delay accuracy of ±25 microseconds at 25 Hz
or ± 2 microseconds at 250 Hz modulation.
d. Frequency Counter. The frequency counter has a
range of 200 to 4000 Hz and a sensitivity of 100 millivolts. It has an accuracy of ± 1 count.
e. Frequency Selective Voltmeter. The frequency
selective voltmeter operates in the range of 5 to 1600
KHz with an accuracy of 0.5 db. It is sensitive from
-90 to +30 dbm and has two bandwidths (250 or
2500 Hz).
f. Impulse Noise Counter. The impulse noise counter has three adjustable ranges and is capable of counting impulses above the three adjusted levels. It is
equipped with a timer and a storage capacity of at
least four digits while counting up to 10 counts per second minimum.
g. Oscilloscope. The oscilloscope may be either a
single or a dual trace with a minimum rise time of 10
microseconds or less.
h. Phase Jitter Meter. The phase jitter meter measures the phase jitter of a single frequency signal. It has
a minimum level range of -30 to 0 dbm with a measuring range of at least 0 to 30 degrees peak to peak jitter. The readout is in degrees peak to peak jitter.
i. Dual-Channel Recorder. The dual-channel
recorder is capable of measuring 0.1 to 500 volts with
a sensitivity of 0.1 volts per millimeter. The chart
speed is adjustable.
j. Signal Test Set. The signal test set measures pulse
speed and percent of break. The test set also generates
pulses used to test signaling circuits and may be used
as a pulse repeater or converter.
k. Test Set, Teletypewriter AN/GGM-15(V)1. This
test set provides a capability for measuring signals in
dc teleprinter/data loops and for transmitting digital
test messages over these loops. The test set includes a
6-1
TM 11-5895-1012-10
signal generator, a signal distortion analyzer, and an
oscilloscope. These items are described below:
(1) Signal Generator SG-860/GGM-15(V). This
unit generates data and telegraph signal outputs with
controlled distortion at speeds up to 9600 baud. Various message options are available for Baudot or
ADCII codes.
(2) Signal Distortion Analyzer TS-2862/
GGM-15(V). This unit performs three major functions: distortion analysis, distortion monitoring, and
error rate determination.
(3) Oscilloscope OS-20/GGM-15(V). This unit is
used to display the signal under analysis.
l. Accessory Items. The accessory items listed below
are required for some of the tests in this chapter.
(1) Test Tone Source. 1000 Hz at - 10 dbm0.
(2) Resistors. Two 300 ohm ± 1%, 1 watt resistors
and one 150 ohm ± 1% 1 watt resistor are required.
(3) Transformer. An center-tapped audio transformer with a 1:1 ratio and an 600/600 ohm impedance is required.
6-3. Test Conditions
a. Patch Panels. Unless otherwise specified, station
to station tests will utilize two equal level patch panels
while in-station tests will utilize one equal level and
one primary patch panel.
b. Service Conditions. Unless otherwise specified,
the circuit to be tested will he out of service. However,
it will be aligned and conditioned for the circuit
characteristics and transmission levels specified in the
applicable TSO.
6-4. Idle Channel (Residual) Noise Test
(fig. 6-1)
a. Purpose. This test will measure idle channel (residual) noise on a circuit between stations or within a
station and will determine circuit compliance with
standard operating requirements. Idle channel or residual noise is a combination of all of the disturbances
occurring within the channel bandwidth and includes
noise caused by nonlinearities, crosstalk, and thermal
effects.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Noise Measuring Test Set.
(2) Terminating plugs (600 ohms) and patch cords.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-1.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in fig6-2
ure 6-1.
(3) Procedure. The receiving station will measure
and record the noise level indication. This measurement will be taken with the Noise Measuring Test Set
set for C message filtering and will be measured in
dbrnc.
(4) Performance Standard. Refer to the Technical
Services Schedules (table 4-2) for the maximum allowable noise for the channel being tested. The noise
measured during this test will not exceed the level
specified by the Technical Services Schedule.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station testing except the local station acts as both transmitter
and receiver.
6-5. Frequency Response Test (fig. 6-2)
a. Purpose. This test will measure frequency
response of a circuit either between stations or within
a station and determine circuit compliance with the
standard operating requirement. Frequency response
is the capability of a system or component to pass a
group of frequencies with the original amplitude relationship relatively intact.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Transmission Test Set.
(2) Noise Measuring Test Set.
(3) Terminating plugs (600 ohms) and patch cords.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. When test has been completed reverse
roles.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-2 and set the equipment as follows:
(a) Patch panel impedance selectors at 600
ohms.
(b) Patch panel frequency control at less than 5
KHZ
(c) Transmission Test Set for 1000 Hz, -10
dbm0 output to the transmit circuit.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in figure 6-2 and set the equipment as follows:
(a) Input selector set for 600 ohms.
(b) Filter selector set for 15 Hz.
(c) Sensitivity set for 0.
(3) Procedure. While the transmitting station varies the frequency and holds the input level constant,
the receiving station will record level readings on the
Noise Measuring Test Set for the following frequencies: 300 Hz, 400 Hz, 500 Hz, 600 HZ, 700 Hz, 800
Hz, 1000 Hz, 1200 Hz, 1400 Hz, 1600 Hz, 1800 Hz,
2000 Hz, 2200 Hz, 2400 Hz, 2600 Hz, and 3000 Hz
(4) Performance Standard. Maximum deviation
TM 11-5895-1012-10
Figure 6-1. Idle channel (residual) noise teat.
from 1000 Hz if - 2 + 6 db.
d. In-Station Test. h-station testing is accomplished in the same manner as station-to-station testing except the local station acts as both transmitter
and receiver.
6-6. Envelope Delay Distortion Test (fig.
6-3)
a. Purpose. This test will measure circuit delay
distortion of circuits between stations or within a
station and determine compliance of circuits with the
standard operating requirements. Circuit delay distortion is the distortion caused by differing amounts of
delay for each of the various frequencies comprising
the intelligence carrying signal. This is tested by transmitting several narrow band modulation envelopes
and measuring the difference between the longest envelope delay and the shortest envelope delay. This difference is called the envelope delay distortion.
b. Test Equipment. Two envelope delay test sets are
required if the teat is to be conducted within a station.
One envelope delay test set is required for each station
the test is to be conducted between two stations.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-3 and set the envelope delay test set
as follows:
(a) Transmit and receive reference.
(b) Signal level of - 10 db.
(c) Carrier frequency of 2000 Hz.
(d) Modulation frequency of 25 Hz.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in figure 6-3 and set the envelope delay test set as follows:
(a) Receive-return reference.
(6) Carrier frequency of 2000 Hz.
(c) Modulation frequency of 25 Hz.
(3) Procedure. With the transmitting station
envelope delay test set set for the reference frequency
of 2000 Hz, record the delay indicated on the envelope
delay test set. The transmitting station will then set
the envelope delay test set for each of the frequencies.
indicated in table 6-1. As each frequency is obtained,
measure the delay and calculate the difference between that delay and the delay measured at the reference frequency of 2000 Hx. This difference may be
either positive (more delay than was measured at 2000
Hz) or negative (less delay than was measured at 2000
Hz).
(4) Performance Standard. The maximum
deviation permissible from the reference frequency of
2000 Hz is indicated in table 6-1.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station test
ing except the local station acts as both transmitter
and receiver.
6-3
TM 11-5895-1012-10
Figure 6-2. Frequency response test.
6-4
TM 11-5895-1012-10
Figure 6-3. Envelope delay distortion test.
6-5
TM 11-5895-1012-10
Table 6-1. Envelope Delay Measurements
d. In-Station Test. In-station testing is accomplished in the same manner as station to station
testing except the local station acts as both transmitter and receiver.
6-8. Minimum Longitudinal Balance Test
6-7. Audio Frequency Test
a. Purpose. This test will measure maximum circuit
frequency change between stations or within a station
and determine compliance of circuits with the standard operating requirements.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Noise Measuring Test Set.
(2) Frequency Counter (two required for in-station
test).
(3) Terminating plugs (600 ohms) and patch cords.
c. Station-to-Station Teat. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-4 and set the equipment as follows:
(a) 1000 Hz Test Tone Source set for - 10 dbm0
coupled to transmit line.
(b) Frequency Counter set to measure ac within
.1 Hz
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-4 and set the equipment as follows:
(a) Frequency Counter set to measure ac within
.1 Hz.
(b) Noise Measuring Test Set set Hi Pass filtering and 600 ohm input.
(3) Procedure. The transmitting station will
measure the Test Tone Source and record the
indication to the nearest .1 Hz. The receiving station
will measure and record the level meter indication on
the Noise Measuring Test Set. The receiving station
will then observe the indication on the Frequency
Meter for one minute and record this measurement.
The two stations will then compare the recorded frequencies and determine the difference between them.
(4) Performance Standard. The maximum
permissible change between the transmitted and
received frequencies is ± 5 Hz.
6-6
transmit and receive circuits and determine circuit
compliance with the standard operating requirements.
Any voltage that causes a current to flow in the same
direction in both conductors of a circuit is a
longitudinal voltage. This can be caused by extraneous
voltages induced into the circuit by either electromagnetic or capacitive coupling to both conductors
from other circuits, or as a result of any external
electrical disturbances. This test measures
of the induced longitudinal voltage on the signal voltage by introducing a known signal voltage and measuring the resulting longitudinal voltage.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Transmission Measuring Test Set (3 required).
(2) Transformer, 1:1 ratio, 600/600 ohm, audio,
center-tapped.
(3) Resistors, 300 ohm ± 1%, 1 watt (2 required).
(4) Resistor, 150 ohm ± 1%. 1 watt.
(5) Terminating plugs (600 ohms) and
c. Station-to-Station Input Teat. Co
station and arrange for one station to act as transmitter and one as receiver. Perform the procedure
below and then reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-5 and set the equipment as fellows:
(a) Transmission test sets jumpered as shown in
figure 6-5 with voltmeter function switch to on.
(b) Patch panel impedance selectors at 600
ohms.
(c) Patch panel frequency selector at less than 5
KHz.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-5.
(3) Procedure.
(a) At the transmitting station, set the frequency of the Transmission Test Set No. 1 to a value
near the top of the
2700 Hz). Adjust the
Set No. 1 for an inpu
mit input as read on Transmission Teat Set No. 3 voltmeter. Note the level in volts and label this V1.
(b) Adjust the range control of
Test Set No. 2 voltmeter for a suitable sensitivity,
measure the low longitudinal signal across the
ohm resistor. Note this level and label it V2.
TM 11-5895-1012-10
Figure 6-4. Audio frequency test.
6 - 7
TM 11-5895-1012-10
(c) Remove the input signal by disconnecting
Transmission Test Set No. 1 and observe Transmission
Test Set NO. 2 voltmeter. If the voltage measured by
Transmission Test Set NO. 2 does not drop in value
when the input signal is disconnected, then the line
noise is probably mashing the reading Of V2. This con&ion must be corrected before the test can be completed.
(d) If the voltage measured by Transmission
Test Set NO. 2 (V2) did drop in value when the input
signal was disconnected then calculate the Longitudinal Balance using the following formula:
Longitudinal Balance (db) = 20 Log10V1/V2.
(4) Performance Standard. Minimum Longitudinal Balance is 40 db.
d. Station-to-Station Output Test. Contact distant
station and arrange for one station to act as transmitter and one as receiver. Perform the procedure
below and then reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-6 and set the equipment as follows:
(a) Transmission test set jumpered as shown in
figure 6-6 with voltmeter function switch to on.
(b) Patch panel impedance selectors at 600
ohms.
(c) Patch panel frequency selector at less than 5
KHz.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-6 and set the equipment as follows:
(a) Transmission test sets jumpered as shown in
figure 6-6 with voltmeter function switches to on.
(b) Patch panel impedance selectors at 600
ohms.
(c) Patch panel frequency selectors at less than
5 KHz.
(3) Procedure.
(a) At the transmitting station, set the frequency of Transmission Test Set No. 1 to a value near
the top of the audio bandwidth (approximately 2700
Hz). Adjust transmission Test Set No. 1 for a level of
- 10 dbm0 as read at the receiving station on Transmission Test Set No. 3 voltmeter. Note this level and
label it V1.
(b) Adjust the range control of Transmission
Test Set No. 2 for a suitable sensitivity and measure
the voltage displayed on Transmission Test Set No. 2
voltmeter. Note this voltage and label it V2.
(c) Calculate the longitudinal balance of the output circuit using the following formula:
Longitudinal Balance (db) = 20 Log10V1/V2.
(4) Performance Standard. The permissable minimum longitudinal balance is 40 db.
e In-Station Testing, In-station testing is accomplished in the same manner as station to station
6-8
testing except the local station acts as both transmitter and receiver in both input and output tests.
6-9. Single Tone Interference Test
a. Purpose. This test will measure maximum single
tone interference of circuits between stations or
within a station and determine circuit compliance with
the standard operating requirements. These interferring tones may come from carrier leak or from
nearby equipment or systems.
b. Test Equipment. Test equipment required to perform this test consists of a Frequency Selective Volt
meter and terminating plugs (600 ohms) and patch
cords.
c. Station-to-Station Test. Contact the distant station and arrange for one station to act as transmitter
and one as receiver. Perform the procedure below and
then reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-7.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-7 and set the frequency selective voltmeter as
follows:
(a) Input impedance set for 600 ohms.
(b) Input attenuator set so that the maximum
level of the single tone interference is included in the
measuring range of the voltmeter.
(3) Procedure.
(a) Slowly sweep the frequency control of the
frequency selective voltmeter through the frequency
range of the channel under test.
(b) Record the power level (in dbm) of the peaks
indicated by the frequency selective voltmeter. Convert this measurement to dbm0 by allowing for the
relative level of the transmission level point at which
the measurement was made.
(c) Convert this level from dbm0 to dbm0 using the conversion chart in figure 6-8. Read the frequency of the interferring tone from the frequency
selective voltmeter and then find the conversion factor
for the frequency in figure 6-8. Then, dbrnc0 = dbm0
+ conversion factor.
(4) Performance Standard. Refer to the Technical
Services Schedules (table 4-2) for the maximum allowable noise for the channel being tested. The maximum
single tone interference (measured in dbrnc0) will not
exceed the level specified by the Technical Services
Schedule.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station testing except the local station acts as both transmitter
and receiver.
6-10. Impulse Noise Test
a. Purpose. This test will measure impulse noise on
TM 11-5895-1012-10
Figure 6-5. Longitudinal balance input test.
6-9
TM 11-5895-1012-10
Figure 6-6. Longitudinal balance output test.
6-10
TM 11-5895-1012-10
Figure 6-7. Single tone interference test.
Figure 6-8. Conversion of dbm to dbrnc0.
6-11
TM 11-5895-1012-10
a circuit between stations or within a station and will
determine circuit compliance with standard operating
requirements. Impulse noise consists of transient
waveforms of various shapes, durations, and amplitudes. It can be caused by natural disturbances such as
lightning or atmospheric static, or by manmade disturbances.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Impulse Noise Counter.
(2) Terminating plugs (600 ohms) and patch cords.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-9.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in figure 6-9 and &the impulse noise counter as follows:
(a) Power switch to ON.
(b) Hold switch to OFF.
(c) Bridge/Term switch to Term.
(d) Weighting selector to Voice.
(e) Input impedance at 600 ohms.
(f) Timing at 15 minutes.
(g) Sensitivity controls set so that all impulse
hits above the reference level specified in the technical
schedules (table 4-2) will be registered or recorded.
(3) Procedure. Receiving station will record all impulse hits above the reference level specified in the
technical schedules (table 4-2).
(4) Performance Standard. The maximum number
of impulse hits permissable in the 15 minute time period is 15.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station test
ing except the local station acts as both transmitter
and receiver.
6-11.
Terminal
Impedance
Test
mit Circuit (fig. 6-10)
of
Trans-
a. h-pose. This test will measure the terminal impedance of the transmit circuit between stations or
within a station and determine circuit compliance with
the standard operating requirement Terminal impedance must be kept within specifications to preclude
impedance mismatch which will result in poor frequency response, excessive loss of signal power, or improper signal level measurements
b. Test Equipment. The following test equipment is
required to perform this test
(1) Transmission Test Set.
(2) Terminating plugs (600 ohms) and patch cords.
c. Station-to-Station Test. Contact distant station
6-12
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in figure 6-10.
(2) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-10 and set the equipment as follows:
(a) Jumper the transmission test set as shown in
figure 6-10.
(6) Set the transmission test set patch panel out
put impedance selector to 600 ohms.
(c) Set the transmission test set patch panel input impedance selector for bridging‘
(d) Set the transmission test set patch panel frequency selector at less than 5 KHz.
(e) Turn on the transmission test set voltmeter.
(3) Procedure. Calibrate the transmission test set
for 1000 Hz and a 1 volt (V1) voltmeter reading.
Switch the calibrate-measure switch back to the measure position, and read the voltage (V2) on the transmission test set voltmeter. Calibrate the transmit impedance from the following expression:
V1 = transmission test set open circuit output voltage
V2 = t-on teat set output voltage when terminated at the receiving circuit.
(4) Performance Standard. The permissable terminal impedance is 600 ohms ± 10%.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station testing except the local station acts as both transmitter
and receiver.
6 - 1 2 . Terminal Im
the terminal impedance of the receive circuit between stations or
within a station and determine circuit compliance with
the standard operating requirements. Terminal impedance must be kept with specifications to preclude
impedance mismatch which will result in poor frequency response, excessive loss of signal power, or improper signal level measurements.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Transmission Test Sets (2 required).
(2) Terminating plugs (600 ohms) and patch cords,
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in fig
TM 11-5895-1012-10
Figure 6-9. Impulse noise test.
6-13
TM 11-5895-1012-10
Figure 6-10. Terminal impedance test for transmit circuit.
ure 6-11 and set the transmission test set as follows:
(a) Jumpered as shown in figure 6-11.
(b) Patch panel impedance selectors at 600
(c) Patch panel frequency selector at less than 5
(d) Voltmeter function switch to on.
(2) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-11 and set the transmission test set
as follows:
(a) Jumpered as shown in figure 6-11.
(b) Patch panel input impedance selector at
bridging.
(c) Patch panel frequency selector at less than 5
(d) Voltmeter function switch to on.
(3) Procedure. The receiving station will calibrate
set for 1000 Hz and set it for 1
on the transmitting station volt-
V1=
6-14
receiving station open circuit voltage
V2=
receiving station voltage terminated in 600 ohms
(4) Performance Standard. The permissable terminal impedance is 600 ohms ± 10%.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station testing except the local station acts as both transmitter
6-13. Harmonic Distortion Test (fig. 6-12)
measures the signal frequency and each
separately and then gives a mathematical
for computing the total harmonic distortion.
b. Test Equipment. The following test equi
required to perform this test:
(1) Transmission Test Set.
(2) Frequency Selective Voltmeter.
(3) Terminating plugs (600 ohms) and patch
c. Station-to-Station Test. Contact distant
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and the
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
TM 11-5895-1012-10
Figure 6-11. Terminal impedance test for receive circuit.
act as transmitter, prepare the transmitting circuit
wn in figure 6-12 and set transmission test set as
ws:
(a) Jumpered as shown in figure 6-12.
(b) Patch panel impedance selectors at 600
ohms.
(c) Patch panel frequency selector at less than 5
KHz.
(d) Turn on voltmeter.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-12 and set the frequency selective voltmeter
as follows:
(a) Input impedance control at 600 ohms.
(b) Bandwidth to 200 or 250 Hz.
(3) Procedure. Transmitting station will calibrate
the transmission test set for a 700 Hz, - 10 dbm0 output. Receiving station will measure the circuit level of
the fundamental (700 Hz), second harmonic (1400 Hz),
third harmonic (2100 Hz), ad fourth harmonic (2800
Hz). Calculate the total harmonic distortion using the
following expression:
(4) Performance Standard. The maximum permistotal harmonic distortion is -40 dbm0.
d. In-Station Test. In-station testing is accomplished in the same manner as station to station
testing except the local station acts as both transmitter and receiver.
6-14. Composite Signal Transmission
Level Test (fig. 6-13)
t of operating conditions
rather than a measurement of circuit parameters. As
such, this test is not applicable as an in-station or
maintenance test.
b. Test Equipment. A noise measuring test set and
patch cords are required to perform this test.
c. Procedure. Prepare the test arrangement shown
in figure 6-13 and set the noise measuring test set for
600 ohms impedance and for bridging. Set the filter
selector for high pass filtering. The circuit being tested
should be in service and the connection should be made
at the VF patch panel. Read and record the indications
on the noise measuring test set.
d. Performance Standard. The required composite
level is the reference level minus 13 dbm0.
6-15. Phase Jitter Test Using Oscila. Purpose. This test will measure phase jitter of a
circuit between stations or within a station and determine circuit compliance with minimum operating
requirements. Phase jitter is the instantaneous deviation from the average phase of the signal and may
be caused by channel induced phase noise or by
additive amplitude noise. Phase jitter may be
measured using an oscilloscope or using a phase jitter
meter. The procedure for measuring phase jitter using
an oscilloscope is given below. The procedure for
6-15
TM 11-5895-1012-10
Figure 6-12. Transmission Test Set
6-16
TM 11-5895-1012-10
Figure 6-13. Composite signal transmission level test.
itter using a phase jitter meter is
6-16.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Test Tone Source, 1000 Hz at - 10 dbm (2 re(4) Performance S t a n d a r d . T h e m a x i m u m
permissable peak-to-peak phase jitter is 15 degrees.
quired).
d. In-Station Test. In-station tasting is ac(2) Oscilloscope.
C. Station-to-Station Test. Contact distant station
complished in the same manner as station to station
and arrange for one station to act as transmitter and
testing except the local station acts as both transone as receiver. Perform the procedure below and then
mitter and receiver.
reverse roles and repeat the procedure.
6-16. Phase Jitter Test Using Phase Jitter
(1) Transmitting Circuit. If the local station is to
Meter (fig. 6-15)
act as transmitter, prepare the transmitting circuit
a Purpose. This test will measure phase jitter of a
circuit between stations or within a station and deterIf the local station is to act
mine circuit compliance with minimum operating
receiving circuit shown in
requirements. Phase jitter is the instantaneous deviation from the average phase of the signal and may
. At the receiving station, patch the
be caused by channel induced phase noise or by additive amplitude noise. Phase jitter may be measured
by using a phase jitter meter or an oscilloscope.
The procedure for use with a phase jitter meter is
given below. The procedure for using an oscilloscope is
given in paragraph 6-15.
b. Teat Equipment. The following test equipment is
required to perform this test:
(1) T&Tone Source, 1000 Hz at - 10 dbm.
(2) Phase Jitter Meter.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and then
reverse roles and repeat the procedure,
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
6-17
TM 11-5895-1012-10
Figure 6-14. Phase jitter testing using an oscilloscope
b. Teat Equipment. The following teat equipment
shown in figure 6-15.
required to perform this test:
(2) Receiving Circuit. If the local station is to act
(1) Signal Test Sets (2 required).
as receiver, prepare the receiving circuit shown in
(2) Terminating plugs (600 ohms) and patch cord
figure 6-15 and set the phase jitter meter as follows:
c. Teat Procedure. Contact distant station and a
(a) Power switch on.
(b) Impedance switch to 600 ohms.
range for one station to act as transmitter and one as
receiver. Prepare the circuit as shown in figure 6-16
(c) Meter select switch to input level.
and perform the procedure below. Then reverse roles
(3) Procedures. At the receiving station, verify
and repeat the procedure.
that the input level is between +10 dbm and -40
(1) Place the controls of each signal test set as
dbm. Then switch the meter select switch to frequency
follows:
and verify that frequency lock has been achieved
(a) Send PPS selector to ON (10 PPS).
Switch the meter select switch to 30° P-P JITTER and
(b) Function switch to Test L & D.
read the meter indication of peak-to-peak phase jitter.
(c) TWD-L, LINE (E) key switch to OFF HOOK
(4) Performance Standard. The maximum
(d) TWD-D key switch to Thru & Meas.
permissable peak-to-peak phase jitter is 15 degrees.
(2) With the off hook signals being sent on the M
d. In-Station Test. In-station testing is aclead at each station, the E lead at both ends should be
complished in the same manner as station to station
grounded as indicated by the extinguishing of the
testing except the local stations act as both transmitter and receiver.
LINE (E) lamps.
(3) At both stations, switch the signal test set
6-17. Station to Station Signaling Test
TWD-L, LINE (E) key switch on O
(fig. 6-16)
on-hook signal being sent to the M lead at each end,
the E lead at both stations should be open as indicated
a. Purpose. This test determines signaling perby
the LINE(E) lamp at both stations being lighted.
formance and compliance with the standard operating
(4) At the transmitting station, place the signal
requirements.
test set controls as follows:
NOTE
(a) Test-Send key switch to Send Osc.
Prior to performing this test, the circuit shall
(b) Meter circuit selector % Break Direct.
be aligned and conditioned to the required
(c) Receive selector to any position except Send
circuit characteristics and transmission levels
and Rec.
specified in the TSO.
6-18
TM 11-5895-1012-10
Figure 6-15. Phase jitter testing using a phase jitter meter.
6-19
TM 11-5895-1012-10
(d) Send selector to E&M line (M = B&G).
(e) Send PPS selector to 10.
(f) Function selector to Send Off Hook for
calibrating and Send & Rec for sending.
(5) At the receiving station, place the signal test
set controls as follows:
(a) Meter Circuit to % Break Direct.
(b) Receive selector to G&O(E).
(c) Function selector to CAL MTR for
calibrating and Send & Rec for measuring.
(6) The receiving station will calibrate the %
break meter for 0% with the transmitting station in
the off hook condition (Function selector to OFF
HOOK).
(7) If SF signaling is being tested, the transmitting station will send continuous pulse streams as
follows:
% Break
Pulse Rate
47
10 PPS
67
10 PPS
47
12 PPS
12 PPS
(8) If DX signaling is being tested, the transmitting station will send continuous pulse streams as
follows:
% Break
Pulse Rate
8 PPS
54
8 PPS
62
12 PPS
54
12 PPS
(9) The receiving station will measure the percent
breaks of the received pulses.
d. Performance Standards. For SF signaling the
percentage breaks recorded at the receiving station
will be 57 ± 10%, irrespective of the pulse rate used.
For DX signaling the
breaks recorded at
the receiving station will be 58
the pulse rate used.
6-18. In-Station Signaling
a Purpose This test determines operational signaling capability.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Signal Test Set.
(2) Signal Unit.
(3) Circuit Termination Panel.
(4) Terminating plug (600 ohms) and patch cords.
c. Test Procedure. To test the receive line of a circuit, prepare the circuit shown in figure 6-17 and perIf a 4 wire circuit is to
transmit lines. If FM
on a separate pair, then connect the
lead from the MISC PATCH panel to the voice circuit
on the
of the primary patch panel.
signal test set as follows:
(1)
(a) Send PPS selector to ON (10 PPS).
(b) TWD-L, LINE (E) selector to Off-Hook.
6-20
(c) Function selector to Test L&D.
(2) Switch the TWD-L, LINE (E) selector to the
ON HOOK position. The circuit termination panel
should ring.
(3) Switch the MISC PATCH lead from the REC
to the XMIT line and terminate the REC line with a
termination plug. Send a ring out from the circuit
termination panel. The LINE (E) lamp should light.
6-19.
Net
Loss
Variation
Test
(fig.
6-18)
a. Purpose. This test will measure maximum net
loss variation between stations or within a station and
determine circuit compliance with the standard
operating requirement.
b. Test Equipment. The following test equipment is
required to perform this test:
(1) Transmission Test Set.
(2) Noise Measuring Test Set.
(3) Dual-Channel Recorder.
(4) Termination plugs (600 ohms) and patch cords
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
one as receiver. Perform the procedure below and them
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmit&, prepare the transmitting circuit in
figure 6-18 and set the transmission test set as
follows:
(a) Patch panel output impedance selector to
600 ohms.
(b) Frequency selector to less than S KHz.
(c) Turn on voltmeter.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in
figure 6-18 and set the noise measuring test set as
follows:
(a) Filter selector at Hi Pass.
(b) Input at 600 ohms.
(c) Sensitivity selectors initially at 0 dbm.
(d) On the recorder, place the chart speed
selector to one inch per minute and the range selector
to 1 volt.
(3) Procedure.
(a) The transmitting station will calibrate the
transmission test set for a 1000 Hz at - 10 dbm0 output signal.
(b) Using only the servo pm drive corresponding
to the upper module, the receiving station will calibrate the recorder to zero the servo pin in the center of
the chart.
(c) The receiving station will record the level of
the 1000 Hz signal for a period of 15 minutes between
0800Z and 1200Z hours and for a period of 15 minutes
between 2000Z and 2400Z hours. During this time, the
transmitting station will vary the output of the transmission test set in 1 db steps, and the receiving station
TM 11-5895-1012-10
Figure 6-16. Station to station signaling teat.
6-21
TM 11-5895-1012-10
Figure 6-17. In-station signaling test.
will verify that the level meter changes in 1 db steps
d. In-Station Test. In-station testing is acand the strip chart recorder shifts the distance in steps
complished in the same manner as station to station
testing except the local station acts as both transStandard. The maximum
mitter and receiver.
is ± 4db.
Figure 6-18. Net loss variation test.
6-22
TM 11-5895-1012-10
6-20. Total Peak and Average Bias Telegraph Distortion Test
(e) INPUT SELECT SWITCH to BRIDGING
H1Z.
WARNING
DANGEROUS VOLTAGES are present during the preparation of the test circuits specified in figures 6-19 and 6-20. Turn all power
switches off before constructing these test
circuits. Failure to observe safety precautions
could result in serious injury or death.
c. Station-to-Station Test. Contact distant station
and arrange for one station to act as transmitter and
as a receiver. Perform the procedure below and then
reverse roles and repeat the procedure.
(1) Transmitting Circuit. If the local station is to
act as transmitter, prepare the transmitting circuit
shown in figure 6-19 and set the AN/GGM-15(V)1
test pattern generator controls as follows:
(a) Use DATAOUTPUT.
(b) P-N switch to P.
(c) DISTORTION SELECT to NO DIST.
(d) LEVEL CODE to 5.
(e) CHARACTER LENGTH to 7.
(f) MESSAGE SELECT to MSG.
(g) BAUD RATE to 75.
(2) Receiving Circuit. If the local station is to act
as receiver, prepare the receiving circuit shown in fig-
(f) BAUD RATESELECTOR to 75.
(g) DISTORTION SELECT to TOTAL PEAK.
(h) TRANSITION SELECT to ALL.
(i) ALARM switch to RESET.
(3) Procedure.
(a) Turn on the power. If the distant station distortion analyzer signal lamp does not light, reverse the
polarity switch. At the transmitting station, transmit
the message "Quick Brown Fox".
(b) At the receiving station, read the total peak
distortion in percent and record it. The place the distortion analyzer ALARM switch to RESET and the
DISTORTION SELECTOR to AVERAGE S/M.
(c) At the transmitting station, transmit the
message "Quick Brown Fox". The receiving station will
mad the average displacement of the mark-to-space
transitions of the input signal as indicated on the percent distortion meter. If the mark indicator lamp is on,
marking bias distortion is indicated. If the space indicator lamp is on, spacing bias distortion is indicated.
Record the results.
(d) Turn power off at both stations.
(4) Performance Standards. The maximum total
peak telegraph distortion permissable is 20%. The
maximum mark or space bias distortion permissable is
12%.
Figure 6-19. Station to station total peak and average bias telegraph teat.
6-23
TM 11-5895-1012-10
Figure 6-20. In-Station total peak and average bias telegraph test.
6-24
TM 11-5895-1012-10
APPENDIX A
REFERENCES
The following publications are available to personnel assigned to the Technical Control Facility:
A Pam 310-4
Index of Technical Manuals, Technical Bulletins, Supply Manuals, (Types 7, 8, and 9), Supply Bulletins, and Lubrication Orders.
A Pam 310-7
US Army Equipment Index of Modification Work Orders.
CAC 310-70-1
Volume I, DCS Technical Control Policy and Facilities; Volume II, DCS Technical Control
Procedures; Volume IV, DCS Technical Control Glossary.
ECEO H500-12-64 DCS Technical Control Engineering Criteria.
Subsystems Design and Engineering Standards for Technical Control Facilities.
IL-STD-188-310
Reservation, Packaging, Packing, and Marking Materials, Supplies and Equipment Used
B 38-100
by the Army.
B 43-0118
Field Instructions for Painting and Preserving Electronics Command Equipment Including Camouflage Pattern Painting of Electrical Equipment Shelters.
M 38-750
The Army Maintenance Management Systems (TAMMS).
A-1
TM 11-5895-1012-10
APPENDIX B
ABBREVIATIONS
B-1
TM 11-5895-1012-10
B-2
TM 11-5895-1012
INDEX
Abbreviations
Administrative storage
Circuit performance
Excessive signal levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Improper terminations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..........................................................
Introduction
Performance monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quality control
Government-owned circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
......................................................
Leased circuits
Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schedules
...............................................
.
............................................
Tests
Trend analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit rerouting
Catastrophic failure procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emergency procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit test procedures
(Quality and maintenance)
Audio frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Composite signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..........................................
Envelope delay distortion.
.........................................
Frequency response
Harmonic distortion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idle channel noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Impulse noise
........................................
Longitudinal balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net loss variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase jitter
Using oscilloscope
Using phase jitter meter
Signaling test
In-station
Station-to-station
Single tone interference
Telegraph bias distortion
Terminal impedance
Receive circuit
transmit circuit
Test conditions
Paragraph
1-7. ,
1-4. ,
Page
1-1
1-1
4-52.
4-53.
4-46.
4-50.
4-44
4-45
4-39
4-43
4-47.
4-48.
4-54.
4-49.
4-55.
4-51.
4-40
4-40
4-45
4-40
4-45
4-43
4-16.
4-15.
4-13.
4-14.
,
,
,
,
4-6
4-5
4-4
4-4
6-7. , 6-6
6-14. , 6-15
6-6. , 6-3
6-5. , 6-2
6-13. , 6-14
6-4. , 6-2
6-10. , 6-8
6-8. , 6-6
6-19. , 6-20
6-15.
6-16.
,
,
6-15
6-17
6-18.
6-17.
6-9.
6-20.
,
,
,
,
6-20
6-18
6-8
6-23
6-12.
6-11.
6-3.
,
,
,
6-12
6-12
6-2
Destruction
Distribution frames
1-5.
2-22.
,
,
1-1
2-27
EIR reporting
Examples of operating TCF's
Berlin
1-6.
,
1-1
3-4.
3-6.
3-7.
3-15.
3-1.
3-3.
,
3-4
,
,
,
3-6
3-12
3-1
4-23.
4-37.
,
,
Pentagon
Pirmasens
Fault isolation
Circuit outages
Circuit status
4-12
4-30
Index 1
TM 11-5895-1012-10
Page
Paragraph
Commercial outages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example procedures
Dc circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voice channel ............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Faults
Baseband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dc . . . . . . . . . . . . . . . .
................ ................................
Multichannel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Single VF channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TCF functional areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voice frequency isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forms and records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Implementation of CSR's
Procedures
.
................................ . . . . . . . . . . . . . . . .
Sample circuit
................
. .. . . . . . . . .
....
TCF responsibilities
..
..
... . . . . . . . . . . . . . . .
TSO's
..
................
Index of publications
. . . . . . . . . . . . . . . .
Installed facilities (See TCF facilities)
4-34.
4-20
4-36.
4-35.
4-27
4-20
4-32.
4-33.
4-31.
4-30.
4-22.
4-28.
4-25.
4-38.
4-26.
4-27.
4-29.
1-3.
4-18
4-19
4-18
4-17
4-12
4-12
4-15
4-30
4-16
4-16
4-17
1-1
4-58.
4-59.
4-57.
4-56.
1-2.
4-47
4-47
4-46
4-46
1-1
Maintenance tests
(See circuit testing procedures)
New equipment acceptance
General
TCF responsibilities
Test and acceptance
Operation practices and methods
On-call circuits
Orderwires
Discipline
Procedure
Types
Service interruptions
Correction of hazardous conditions
Emergency
Scheduled
..
Station management
......... .
Approach. . . . . . . . . . . . .
Facilities and usage
System management
Technical controller duties
TELECON circuits
..
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
.....
. . . . . . . . . . . . . . . .
4-60.
4-61.
4-62.
,
,
,
4-49
4-49
4-49
. . . . . . . . . . . . . . . . .
4-9.
,
4-3
. . . . . . . . . . . . . . . . ......
................
.....
. . . . . . . . . . . . . . . .
4-7.
4-6.
4-5.
,
,
,
4-3
4-2
4-2
................
....
. . . . . . . . . . . . . . . .
................
4-12.
4-11.
4-10.
,
,
,
4-4
4-4
4-3
. . . . . . . . . . . . . . . .
. . . .
. . . . . . . . . . . . . . . .
....
................
................
................
................
. . . . . . . . . . . . . . . .
..
4-2.
4-3.
4-1.
4-4.
4-8.
,
,
,
,
,
4-1
4-1
4-1
4-2
4-3
,
,
,
,
,
4-7
4-6
4-5
4-6
4-6
,
,
,
,
,
,
4-39
4-37
4-31
4-39
4-31
4-37
4-39
,
2-33
Patching
4-21.
Dc facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-18.
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17.
4-19.
Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-20.
VF facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . .
Performance standards
4-43.
Conduct of tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-42.
Digital distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General
4-39.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-45.
Recording test results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-40.
Technical schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-41.
. . . . . . . . . . . . . . . .
4-44.
Test reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
..
2-23.
Power facilities . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
.
.
2-29.
Index 2
TM 11-5895-1012-10
Paragraph Page
QC test (see Circuit testing procedures)
Quality control testing
(See circuit performance)
Representative TCF equipment
Circuit conditioning . . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . . . . . . . . . . . . . .
DLIU
. . . . . .. . . . . .. . . . . .. . . . . .
General
. . . . . .. . . . . .. . . . . .. . . . . .
Other conditioning equipment. . . . . . . . . . . . . . . . . . . . . . . .. . . . . .
Patch panels
Dc
. . . . . . . . . . . . . . . . . . . . . . . ......
Miscellaneous
. . . . . . . . . . . . . . . . . . . . . . . .
VF and E&M
. . . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . .
Signaling . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
Test equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rerouting (See circuit rerouting)
............
............
Scope
Signal facilities . . . . . . . . . . . . . . . . . . . . . . . .
.
. . . . . . . . . . . .
............
Station cabling . . . . . . . . . . . .
Station maintenance
Checks and services
. . . . . . . . . . . .
Daily . . . . . . . . . . . .
. . . . . . . . . . . .
Periods . . . . . . . . . . . . . . . . . . . . . . . .
Quarterly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Weekly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
............
Prevention maintenance . . . . . . . . . . . . . . . . . . . . . . . .
System service interfaces
AUTODIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AUTOVON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common user network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Communications facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .
Relay centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
............
............
Transmission media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. ............
TCF function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TCF interfaces
Ac power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .
Classes of power . . . . . . . . . . . . . . . . . . . . . . . .
........................
Configuration . . . . . . . . . . . . . . . . . . . . . . . .
Digital data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
............
Distribution frames
. . . . . . . . . . . . . . . . . . . . . . . .
............
Generating equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal . . . . . . . . . . . . . . . . . . . . . . . .
..
............
. . . . . . . . . . . .
Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power distribution . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .
. ...
. . . . . . . . . . . .
Stating cabling . . . . . . . . . . . .
...
Uninterruptible power supply (UPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
............
.
. ............
Voice frequency . . . . . . . . . . . .
Wideband . . . . . . . . . . . . . . . . . . . . . . . .
...
. ............
. . .
. . .
. . .
TCF purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
......
TCF responsibilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. .....
......
TCF signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical control facility
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
........................
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Responsibilities
Additional
............ ..... . . . . . . . . . . . .
General
2-31.
2-39.
2-30.
2-33.
,
,
,
,
2-36
2-54
2-34
2-37
2-36.
2-37.
2-35.
2-34.
2-33.
,
,
,
,
,
2-38
2-45
2-33
2-37
2-50
1-1.
2-17.
2-18.
2-19.
2-20.
2-21.
,
,
,
,
,
,
1-1
2-15
2-24
2-24
2-26
2-27
6-3. , 5-1
5-2. , 5-1
5-5. , 5-2
5-4. , 5-1
5-6. , 5-2
5-1. , 5-1
2-13.
2-12.
2-8.
2-10.
2-7.
2-11.
2-9.
,
,
,
,
,
,
,
2-9
2-8
2-4
2-6
2-4
2-8
2-4
2-2.
,
2-1
2-25.
2-24.
2-16.
2-18.
2-22.
2-26.
2-20.
2-29.
2-23.
2-27.
2-21.
2-28.
2-17.
2-19.
2-1.
2-3.
2-6.
2-14.
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
2-28
2-23
2-12
2-24
2-27
2-28
2-26
2-33
2-27
2-29
2-27
2-30
2-15
2-24
2-1
,
,
2-3
2-11
2-2.
2-15.
2-1.
,
,
,
2-1
2-11
2-1
2-5.
2-3.
,
2-2
2-1
Index 3
TM 11-5895-1012-10
To subscribers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical controllers duties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test equipment description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test procedure introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test procedures (see circuit testing
procedures)
Paragraph
Page
2-4.
2-6.
4-4.
6-2.
6-1.
2-2
2-3
4-2
6-1
6-1
,
,
,
*US GOVERNMENT PRINTING OFFICER 1978-703-128558
Index 4
TM 11-5895-1012-10
BERNARD W. ROGERS
General, United States Army
Chief of Stuff
Official:
B
J.C. PENNINGTON
r General, United States Army
The Adjutant General
(1)
USACC (1)
Armies (1)
HISA (Ft Monmouth) (33)
Ft Huachuca (2)
Ft Richardson (ECOM Ofc) (1)
*Ft Carson (2)
Ft Gillem (2)
USASIGS (10)
Svc Colleges (l)
USAERDAA (1)
USAERDAW (1)
Sig FLDMS (1)
ARNG & USAR: None.
For explanation of abbreviations used, see AR310-50.
Figure FO-1. Simplified power distribution diagram.
Figure FO-2. Vf primary or equal level patch panel, interconnection diagram
Figure FO 2 Vf primary or equal level patch panel, interconnection diagram
TM 11-5895-1012-10
Figure FO-3. Primary dc patch panel, interconnection diagram.
TM 11-5895-1012-10
Figure FO-4. Dc patch panel (receive) with cut keys and lamps, interconnection diagram
TM 11-5895-1012-10
Figure FO-5. Dc patch panel (transmit) with cut keys and lamps, interconnection diagram
TM 11-5895-1012-10
Figure FO-6. TCF, Pirmasens, signal diagram
TM 11-5895-1012-10
Figure FO-7. TCF, Pirmasens, floor plan.
TM 11-5895-1012-10
Figure FO-8. TCF, Berlin, signal diagram.
TM 11-5895-1012-10
Figure FO-9. TCF, Berlin, floor plan
TM 11-5895-1012-10
Figure FO-10. TCF, Pentagon, signal diagram.
Figure FO-11. TCF, Pentagon, floor plan.
TM 11-5895-1012-10
Figure FO-12. TCF, Pentagon, floor plan.
Figure FO-13. Typical black digital circuit IDF connection diagram
TM 11-5895-1012-10
Figure FO 13. Typical black digital circuit IDF connection diagram
TM 11-5895-1012-10
Figure FO-14. Universal digital patch panel, interconnection diagram.
TM 11-5895-1012-10
Figure FO-15. Universal digital patch panel black send circuit strapping diagram
TM 11-5895-1012-10
Figure FO-16. Universal digital patch panel black receive circuit strapping diagram
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Liberated Manuals -- free army and government manuals
Why do I do it? I am tired of sleazy CD-ROM sellers, who take publicly
available information, slap “watermarks” and other junk on it, and sell it.
Those masters of search engine manipulation make sure that their sites that
sell free information, come up first in search engines. They did not create it...
They did not even scan it... Why should they get your money? Why are not
letting you give those free manuals to your friends?
I am setting this document FREE. This document was made by the US
Government and is NOT protected by Copyright. Feel free to share,
republish, sell and so on.
I am not asking you for donations, fees or handouts. If you can, please
provide a link to liberatedmanuals.com, so that free manuals come up first in
search engines:
<A HREF=http://www.liberatedmanuals.com/>Free Military and Government Manuals</A>
– Sincerely
Igor Chudov
http://igor.chudov.com/
– Chicago Machinery Movers
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