TM 11-6625-928-35 · Communication System Control C-6533/ARC (part of MK-994/AR). Communication...

TM 11-6625-928-35DEPARTMENT OF THE ARMY TECHNICAL MANUAL

DIRECT SUPPORT, GENERAL SUPPORT,

AND DEPOT MAINTENANCE MANUAL

TEST FACILITIES KITMK-994/AR

This copy is a reprint which includes current

pages from Changes 1 through 8.

HEADQUARTERS, DEPARTMENT OF THE ARMYDECEMBER 1968

DANGEROUS VOLTAGES EXIST IN THIS EQUIPMENT

Be careful when working around the +27.5-volt dc and 115-volt, 400-Hzinputs to the equipment. These voltages are also available at front panelconnectors.

DON’T TAKE CHANCES

CAUTION

To avoid transistor and integrated circuit damage, make sure that all powerswitches are in the OFF position before changing cable connections. Check thesource voltage and polarity before making connections. TRANSISTORSAND INTEGRATED CIRCUITS MAY BE PERMANENTLY DAM-AGED BY IMPROPER VOLTAGE OR POLARITY.

WARNING

TM 11-6625-928-35C 8

CHANGE

No. 8

HEADQUARTERSDEPARTMENT OF THE ARMY

Washington, DC, 13 September 1985

DIRECT SUPPORT, GENERAL SUPPORTAND DEPOT MAINTENANCE MANUAL

TEST FACILITIES KITMK-994/AR (NSN 6625-00-802-7191) and

MK-994A/AR (NSN 6625-01-189-7882)

TM 11-6625-928-35, 9 December 1968, is changed as follows:

1. Title of the manual is changed as shown above.2. This change includes information required to reflect MWO 11-6625-928-30-1.3. Remove old pages and insert new pages as indicated below. New or changed material is indicated by a vertical barin the margin of the page. Added or revised illustrations are indicated by a miniature pointing hand.

Remove pages Insert pages

i and ii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .l-l and l-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-l and 2-2 . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . 2-7 and 2-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-l and 3-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4.1 and 3-4.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..None . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .None . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. File this change sheet in the front of the publication for reference purposes.

i and ii1-1 and 1-22-1 and 2-22-7 and 2-83-1 and 3-23-4.1 and 3-4.23-38.7 through 3-38.12A-1 and A-25-295-41

By Order of the Secretary of the Army:

Official:

JOHN A. WICKHAM JR.General, United States Army

Chief of Staff

DONALD J. DELANDROBrigadier General, United States Army

The Adjutant General

DISTRIBUTION:To be distributed in accordance with DA Form 12-36, Operator,

Direct and General Support Maintenance requirements for MK-994/AR.

TM 11-6625-298-35

T E C H N I C A L M A N U A L HEADQUARTERSDEPARTMENT OF THE ARMY

No. 11-6625-928-35 WASHINGTON , DC, 9 December 1968

CHAPTER 1

2.

3.

SECTION I.

II.

III.

CHAPTER 4.

SECTION I.

SECTION II.

CHAPTER 5.

APPENDIX A.

Direct Support, General Support,and Depot Maintenance Manual

TEST FACILITIES KIT MK-994/AR(NSN 6625-00-802-7191)

AND MK-994A/AR(NSN 6625-01-189-7882)

INTRODUCTION

scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Maintenance forms. records and reports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consolidated Index of Army Publications and Blank Forms. . . . . . . . . . . . . . . . . . . . . . . .

Reporting errors and recommending

improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reporting equipment improvement

recommendations (EIR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Common names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CIRCUIT FUNCTIONING

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dc power distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radio test circuit analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Communication control test circuit

analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Automatic direction finder circuit

analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Interconnecting Box J-4247/AR circuit analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DIRECT AND GENERAL SUPPORT MAINTENANCE

General Troubleshooting Information

General instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Organization of troubleshooting

procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test equipment required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Localizing troubles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RepairsGeneral parts replacement techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cable wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dummy Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Support Testing Procedures

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test equipment, tools, and materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fabrication of voltage divider and

special test probes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Modification work orders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Physical tests and inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radio test circuit tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Communication control test circuit tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Adf test circuit tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interconnecting Box J-4247/AR circuit tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DEPOT MAINTENANCE AND OVERHAUL STANDARDS

Depot Maintenance

Scope of depot maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tools, test equipment, and materials

required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Depot Overhaul Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FINAL ILLUSTRATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1

1-1.1

1-1

1-1

2-1

2-1

2-1

2-5

3-1

3- 1

3-1

3-1

3-1

3-8

3-8

3-26.3

3-27

3-28

3-28

3-283-32

3-35

3-38.7

4-1

4-1

4-1

5-1

A-1

Change 8

Paragraph

1-11-1.11-2

P a g e

1-3

1-3.1

1-41-11-1

2-12-22-3

2-4

2-52-6

2-62-8

3-1

3-23-33-43-5

3-63-73 -7 .1

3-83-93-10

3 -273-273-27

3-11

3-12

3-13

3-143-15

3-16

3-17

4-1

4-24-3

i

TM 11-6625-928-35

3-13-2

3-3

3-4

3-53-6

3-7

3-9

3-10

3-11

3-12

3-13

3-14

3-15

3-16

3-17

3-18

3-19

5-1

5-2

5-3

5-4

5-5

5-6

5-7

5-85-9

5-10

LIST OF ILLUSTRATIONSTitle

Typical system test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from right edge, altered for usewith RT-l167/ARC-164(V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from panel right edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, rear view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, oblique view from panel bottom edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from panel top edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from panel bottom edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chassis, viewed from panel left edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from panel top edge withID-1351A and MP 104 removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis, viewed from panel left edge with

ID-1351A and MP 104 removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radio coaxial fittings, exploded view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Adf coaxial fitting, exploded view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assembly instructions for type BND RF cable connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assembly instructions for type N RF cable

connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Assembly instructions for type TPS RF cableconnectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Assembly instructions for type DM RF cable

connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Assembly instructions for RF cable

connector SM-A-595802-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Assembly instructions for RF cableconnector SM-A-595804A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test power supply and voltage divider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Front Panel, Interconnecting Box J-4247/AR. . . . . . . . . . . . . . . . .

Power and ground circuit distribution,

s i m p l i f i e d s c h e m a t i c d i a g r a m . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radio test circuit, simplified schematic

diagram (four parts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microphone amplifier test circuit, simplified schematic

diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Headset amplifier test circuit, simplified

schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Adf and gyro test circuits, simplified schematic

diagram (two parts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DELETED

Test Facilities Kit MK-994/AR (part No. SM-B-625662)wiring diagram (four parts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Panel assembly, exploded view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis assembly exploded view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interconnecting Box, interface wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page No.

2-2

3-4.23-93-103-113-123-133-14

3-15

3-163-16.13-16.23 - 1 6 . 3

3-16.4

3-16.5

3-16.6

3-16.7

3-16.83-283-293-38.12

5 - 3

5-5, 5-75-9, 5-11

5-13

5-15

5-17, 5-19

5-29, 5-315-33, 5-355-375-395-41

Figure No.

2-13-0

3-8

ii Change 8

TM 11-6625-928-35

CHAPTER 1

INTRODUCTION

1-1. Scopea. This manual contains instructions for direct,

general support and depot maintenance for TestFacilities Kit MK-994/AR and MK-994A/AR (main-tenance kit). It includes instructions appropriate todirect and general support and depot maintenancefor troubleshooting, testing, and repairing theequipment, and replacing maintenance parts. It alsolists tools, materials, and test equipment requiredfor direct and general support and depot main-tenance. Detailed functions of the maintenance kitare covered in chapter 2.

b. The complete technical manuals for thisequipment include TM's 11-6625-928-12, 20P, and34P.

1-1.1. Maintenance Forms, Records,and Reports

a. Reports of Maintenance and unsatisfactory Equip-ment. Department of the Army forms and pro-cedures used for equipment maintenance will bethose prescribed by DA Pam 738-750 as contained inMaintenance Management Update.

b. Report of Packaging and Handling Deficiencies. Fillout and forward SF 364 (Report of Discrepancy(ROD)) prescribed in AR 735-11-2/DLAR 4140.55/NAVMATINST 4355.73A/AFR 400-54/MCO4430.3F.

c. Discrepancy in Shipment Report (DISREP)(SF361).Fill out and forward Discrepancy in ShipmentReport (DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33C/AFR 75-18/MCOP4610.19D/DLAR 4500.15.

Equipment

Wattmeter AN/URM-120.

Signal Generator AN/URM-103.Signal Generator AN/URM-44A.

Signal Generator AN/URM-127.

Multimeter ME-26B/U.

Electronic Voltmeter ME-30A/U.

Headset-Microphone H-101A/U.RF Signal Generator Set AN/URM-25D.

Multimeter TS-352B/U.

Electronic Voltmeter AN/URM-145.Electronic Voltmeter AN/USM-98.

Impedance Adapter MX-1487/URM-25D.

Facility +27.5 ± 0.5-volt dc power source.

Facility 115 ± 5-volt, 400-Hz, single-phase power source.

Detector DT-307/G.

Oscilloscope AN/USM-140A.

Communication System Control C-6533/ARC (part of MK-994/AR).

Communication System Control C-6533/ARC (under test).

1-2. Consolidated Index of ArmyPublications and Blank Forms

Refer to the latest issue of DA Pam 310-1 to deter-mine whether there are new editions, changes oradditional publications pertaining to theequipment.

1-3. Reporting Errors and Recom-mending Improvements

You can help improve this manual. If you find anymistakes or if you know of a way to improve the pro-cedures, please let us know. Mail your letter or DAForm 2028 (Recommended Changes to Publications andBlank Forms) direct to: Commander, US ArmyCommunications-Electronics Command and Fort Mon-mouth, ATTN: AMSEL-ME-MP, Fort Monmouth,New Jersey 07703-5007.

1-3.1. Reporting Equipment improve-ment Recommendations (EIR)

If your Test Facilities Kits MK-994/AR orMK-994A/AR need improvement, let us know. Send usan EIR. You, the user, are the only one who can tell uswhat you don’t like about your equipment. Let us knowwhy you don’t like the design. Put it on an SF 368(Qua l i ty Def ic iency Repor t ) . Mai l i t t oCommander, US Army Communications-ElectronicsCommand and Fort Monmouth, ATTN: AMSEL-ME-MP, Fort Monmouth, New Jersey 07703-5007. We’llsend you a reply.

1-4. Common NamesThe following are common names of equipment referred toin this manual:

Common nameWattmeter.

Fm generator.

Am generator.

Audio generator.

Multimeter.Voltmeter.

Headset, or microphone.

RF generator.

Ohmmeter.

RF voltmeter.Dc voltmeter.

50-ohm termlnatmn.+28-volt power source.

115-volt. 400-Hz power source.

Detector.

Oscilloscope.

COMM CONT NO. 1.

COMM CONT NO. 2.

Change 8 1-1

TM 11-6625-928-35

Equipment Common name

Radio Set AN/ARC-114, -114A.Radio Set AN/ARC-115.Radio Set AN/ARC-116.Radio Set Control C-7392/ARN-89.Radio Receiver R-1496/ARN-89.Receiver-Transmitter, Radio RT-1167/ARC-164(V).Radio Set R-1354/ARC-186(V).Standing Wave Ratio Indicator IM-157/U50-Ohm BNC adapter (part of Electronic Voltmeter AN/URM-145)Test Facilities Kit MK-1191/ARStandard Lightweight Avionics EquipmentCable Assembly, Radio Frequency CC-3475/UCable Assembly, Special Purpose, Electrical CX-10889/U

Cable Assembly, Special Purpose, Electrical CX–10890/UCable Assembly, Special Purpose, Electrical CX–10891/UCable Assembly, Special Purpose, Electrical CX-10892/UCable Assembly, Special Purpose, Electrical CX-10893/AR

Cable Assembly. Radio Frequency CG-3477/U

Cable Assembly, Radio Frequency CG-2340A/U

Cable Assembly, Radio Frequency CG-3476/UCable Assembly, Radio Frequency CG-3478/UCable Assembly, Radio Frequency CG-3479/UCable Assembly, Radio Frequency CG-3481/UCable Assembly, Radio Frequency CG-3482/UCable Assembly, Radio Frequency CG-3480/UCable Assembly, Special Purpose, Electrical CX-10888/UCable Assembly, Power, Electrical CX-10886/ARCable Assembly, Power, Electrical CX-10887/AR

Cable Assembly, Radio Frequency CG-3483/U

Cable Assembly, Radio Frequency CG-3474/U

Cable Assembly, Special Purpose, Electrical CX-10894/ARCable Assembly, Radio Frequency CG-3484/ARCable Assembly, Special Purpose, Electrical, Branched CX-11985/ARInterconnecting Box J-4247/AR (part of MK-994A/AR)

Radio set.Radio set.Radio set.Adf control.Adf receiver.Radio set.Radio set.Swr indicator.

50-ohm termination

GS accessories kitSLAEW1W2 or W3

W4W5 or W6W7 or W8

W9

W10W11

W12, W13, or W14W15W16W17

W18W19W20 or W21

W22W23W 24

W25

W26W27, W28, W29, W30, or W31W32Interconnecting box

1-2 Change 8

TM 11-6625-928-35

CHAPTER 2

CIRCUIT FUNCTIONING

2-1. GeneralThe MK-994/AR, in conjunction with standard testequipments, provides the capability for testing andperforming checkout and/or repair of the electronicequipment that constitutes the SLAE and the ARC-164(V). In addition to this equipment, Test FacilitiesKit MK-994A/AR provides the capability to test theRT-1354/ARC-186(V), RT-1300/ARC-186(V),C-10604(V)/ARC-186(V), C-10606(V)/ARC-186(V),CM-482/ARC-186(V), and CM-492/ARC-186(V).Communication System Control C-6533/ARC andHeading-Radio Bearing Indicator ID- 135 l/A aremajor units of the maintenance kit. For detailed infor-mation on these two major units, refer to the appli-

cable technical manual (app. A). The direct current(dc) power distribution is common to all test circuitsand is discussed in paragraph 2-2.

2-2. Dc Power DistributionThe dc power (+28-volt) distribution within themaintenance kit is shown in figure 5-1. The dc poweris applied to the maintenance kit at front panel DCPOWER connector J28-A. The +28 volts is thenapplied through 10.0-ampere DC POWER circuitbreaker CB2 to terminal board TB2-4. Jumpers onterminal board TB2 connect the +28 volts atTB2-4 to TB2-1, 2, 3, and 5 for application to pointswithin the maintenance kit. The +28 volts atterminal board TB2-4 is also applied to DC POWERindicator light DS3 as a front panel indication of dcpower presence. The +28-volt return at DC POWERconnector J28-B is connected to terminal boardTB3-1. Jumpers at terminal boards TB3-1 throughTB3-6 provide ground points for maintenance kitCircuitry.

2-3. Radio Test Circuit Analysisa. Radio tests are perfO rmed with the

r a d i o s e tbeing tested connected to RADIO SET NO. 1 con-nector J1 (fig. 2-1 and fig. 5-2) of the maintenancekit. A selected am or fm generator, connectedthrough cable W15 to SIGNAL INPUT connectorJ12 provides a test signal. A wattmeter connectedbetween POWER METER OUTPUT connectorJ9 and POWER METER INPUT connector J10provides for measuring transmitter power. Electrical51-ohm dummy load AT1 provides the radiofre-

quency (RF) load. The RF antenna connector ofthe radio set under teat should be connected throughcable W12 to T/R ANTENNA connector J11 toproperly load the antenna circuit when transmit-receive (tr) relay K1 is energized. With tr relay K1deenergized, the test signal, which is applied throughcable W15 to SIGNAL INPUT connector J12, isconnected through connector P4, coaxial adaptersCP1 (9.5 decibels (db)), CP6, CP7, attenuator AT5(12 db), connector P5, closed contacts B3 and B2 oftr relay K1, T/R ANTENNA connector J11, andcable W12 to the radio set under test (fig. 2-1 and3-9). RADIO ANTENNA FUNCTION switch S1(fig. 5-2) is retained in position XCVR unless thehoming capability of the radio set under test is beingchecked. RADIO TEST switch S2 provides selectionof the circuit function to be tested.

b. An audio generator, connected to RADIOTEST INPUT connector J17 (E, fig. 5-2), providesaudio signals. With RADIO TEST switch S2 set to4, the audio signals are applied to the audio circuitsin the radio set under test through RADIO TESTINPUT connector J17, switch S2A and RADIOSET NO. 1 connector J1-Y. Audio from the radioset under test is applied to maintenance kit Com-munication System Control C-6533/ARC (COMMCONT NO. 1) through RADIO SET NO. 1 con-nector J1-d (C, fig. 5–2), terminal board TB1-4,TBI-5 and COMM CONT NO. 1 connectors J1-KK, MM, PP, SS, and UU, The audio signal iscontrolled by COMM CONT NO. 1 switching cir-cuits and amplified by the headset amplifier. Theamplified audio is applied through COMM CONTNO. 1 connectors J1-TT and XX, HEADSETS 1connectors J15-B and D, and cable W20 or W21 toHeadset-Microphone H-101A/U to provide auralmonitoring of audio signal.

c. With HEADSETS 1 switch S6 (B, fig. 5-2) setto TRANSMIT, a ground at COMM CONT No. 1connector J1-K is applied to terminal X2 of trans-mit-receive (tr) relay K1. With RADIO ANTENNAFUNCTION switch S1 set to XCVR, +28 volts isapplied through switch S1, energizing relay K1.With RADIO TEST switch S2 set to 4, relay K1 canalso be energized by application of a ground (retrans-mit control input) through switch S2. When relayK1 is energized, a ground is applied from TB3-3through terminals Al and A2 of relay K1 to TB4-4.This ground is applied to RADIO SET NO. 1 con-

Change 8 2-1

Figure 2-1.

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11-6625-928-35

2-2

Ch

ang

e 3

nector J1-Z for use as the retransmit control inputsignal. With the radio set connected to connector J1and set for retransmit, the retransmit control inputsignal applied through connector J1-Z will energizethe tr relay in the radio set. An interlock is providedfor the transmit mode of operation. RADIO AN-TENNA FUNCTION switch S1 must be set toXCVR to permit a radio set under test to be placedin the transmit mode of operation. Switch S1 XCVRposition applies +28 volts to relay K1 coil terminalXl. Relay K1 is energized by grounding relay K1coil terminal X2. When K1 is deenergized, the trans-mit control and retransmit control signals will notbe applied to the radio set under test. With the trrelay in the radio set energized, the radio set undertest is in the transmit mode and transmit audio sig-nals are picked up by Headset-Microphone H-101A/U connected to HEADSETS 1 connector J15(D, fig. 5-2). The audio signal from Headset-Microphone H-101A/U is applied through cableW20 or W21, HEADSETS 1 connectors J15-A andC, and COMM CONT NO. 1 connectors J1-A and Cto the microphone amplifier input, where it is ampli-fied and applied through connector J1-F, L, P, R, orV, depending on the position of the COMM CONTNO. 1 selector switch, terminal ‘board TB3-8, andRADIO SET NO. 1 connector J1-K to the radio setunder test where it is gated, amplified, and reappliedto connector J1-d (C, fig. 5-2). The transmit audiosidetone on connector J1-d is amplified and moni-tored as explained in b above.

d. With the radio set under test in the transmitmode, radio set RF output is applied through T/RANTENNA connector J11 and closed contacts B2and B1 of relay K1 to POWER METER INPUTconnector J10 (A, fig. 5-2). Relay K1 is energizedas explained in c above. The RF from connectorJ10 may be applied through cable W10, the watt-meter, cable W11, POWER METER OUTPUTconnector J9 and connector P3 to 51-ohm dummyload AT1 (fig. 3-3 and A, fig. 5-2). The power outputof the radio set under test is indicated on the watt-meter when HEADSETS 1 switch. S6 is held atTRANSMIT.

e. With the radio set under test in the receivemode, the am or fm generator output test signal atSIGNAL INPUT connector J12 is applied to theradio set under test (A, fig. 5-2), as explained ina above.

f. RADIO TEST switch S2 may be set at any of12 positions. When in position OFF,switch S2 has no effect on the maintenance kit sinceno circuit is established by any of the switch sections(E, fig. 5-2). Effects of switch S2 on the maintenancekit operation are covered in paragraphs g throughp below.

TM 11-6625-928-35

g. With RADIO TEST switch S2 set to 1, theX-mode guard receiver audio output signal from theradio set under test is applied through RADIO SETNO. 1 connector J1-b and switch S2C to RADIOTEST OUTPUT connector J18-A. A ground fromE17 is applied through TB2-9, 10, 11, and 12 toRADIO TEST OUTPUT connector J18-B (E, fig.5-2). A voltmeter connected to connector J18 pro-vides for measurement of the X-mode guard receiveroutput of the radio set under test.

h. With RADIO TEST switch S2 set to 2, theretransmit audio receive signal from the radio setunder test at RADIO SET NO. 1 connector J1 isapplied through connector J1-X and switch S2C,and the retransmit audio signal from the radio setunder test at RADIO SET NO. 2 connector J2 isapplied through connector J2-Y and switch S2C toRADIO TEST OUTPUT connector J18 and can bemonitored on a voltmeter connected to connectorJ18. A retransmit control signal from connector Jl-H-is applied through switch S2E to CONTROLSIGNAL light DS2 causing the lamp to light. Thisretransmit control signal is also applied to connectorJ2–Z to operate a second radio set in the retransmitmode (E, fig. 5-2).

i. With RADIO TEST switch S2 set to 3, the-X-mode receiver output signal from the radio setunder test is applied through RADIO SET NO. 1connector J1-c and switch S2C to RADIO TESTOUTPUT connector J18. A ground (X-mode con-trol) from E15 is also applied through TB3-6,TB3-5, and switch S2D to connector J1-g (E, fig.5-2). This ground at connector J1-g enables theX-mode receiver output circuit. Connector J17is also connected to J1-J providingaudio for X-mode transmit function.

j. With RADIO TEST switch S2 set to 4 andRADIO ANTENNA FUNCTION switch S1 set toXCVR, relay K1 is energized (B, fig. 5-2). A groundfrom E15 is applied through TB3-6, TB3-5, andS2D to terminal X2 of relay K1. Relay Kl, whenenergized, provides a ground to RADIO SET NO. 1connector J1-Z (c above). A ground may also beapplied to connector J1-Z from RADIO SET NO. 2connector J2–H when operating two radio sets in theretransmit mode. With a ground on connector J1-Zand the radio set function switch set to RETRANS,the transmit-receive relay in the radio set under testis energized and the radio set is in the transmitmode. The output from an audio generator con-nected to RADIO TEST INPUT connector J17 (E,fig. 5-2) is applied to connector J1-Y through switchS2A. Retransmit audio may also be applied toconnector J1-Y from RADIO SET NO. 2 connectorJ2-X when operating two radio sets in the retransmitmode. Received audio may be monitored at RADIOTEST OUTPUT connector J18 during tests (E, fig.5-2).

Change 6 2-3

TM 11-6625-928-35

k. An additional radio set may be connected toRADIO SET NO. 2 connec tor J2 to t es tretransmit, am. transmitter audio modulationand distortion, and transmit receive modes ofoperation. Radio set No. 2 is controlled byCommunication System Control C-6533/ARCconnected to COMM CONT NO. 2 connector J3.The HEADSETS 2 connector J16 and switch S7are used with radio set No. 2. When radio set No.2 is used as a receiver, a simple antenna, or asignal generator in series with a 6-db, or larger,attenuator, must be connected directly to theradio set antenna connector. When radio set No. 2is used as a transmitter, its antenna connectorshould be connected to a 50-ohm dummy load orantenna.

l. With RADIO TEST switch S2 set to 5, thesignal from an audio generator is applied throughRADIO TEST INPUT connector J17, switchS2A, and RADIO SET NO. 1 connector J1-J tothe radio set under test for use as the X-modetransmit audio input (E, fig. 5-2). Also, relay K7is energized with switch S2 set to 5 and disablestone modulation in the transmitter of Radio SetAN/ARC-114 under test. This action enables fmdev ia t ion to be measured when ex te rna lmodulation is applied (E, fig. 5-2). With switchS2 set to 5, a 6.8-volt automatic gain control (age)disable signal is applied through switch S2B toRADIO SET NO. 1 connector J1-F. The 6.8-voltagc disable signal is required for receiver agctests.

m. With RADIO TEST switch S2 set to 6, thereceived audio input signal from the radio setunder test is applied through RADIO SET NO. 1connector J l-d, TB1-4, TBl-5, and switch S2C toRADIO TEST OUTPUT connector J18 (E, fig. 5-2). The received audio signal can also bemonitored on the headse t connec ted toHEADSETS 1 connector J15 (b above).

n. With RADIO TEST switch S2 set to 7, a+6.8-volt automatic gain control (age) disable

signal is applied through S2B to RADIO SETNO. 1 connectors J1-G. The +6.8-volt signal isrequired for guard received agc tests (pin G). The+6.8-volt signal is developed across Zener diode

CR1 and applied from terminal A1-E20 to switchS2B (E, fig. 5-2). Received audio may bemonitored at RADIO TEST OUTPUT connectorJ18 during the tests (E, fig. 5-2).

o. With RADIO TEST switch S2 set to 8, thehoming enable output signal from Radio SetAN/ARC-l 14 under test is applied throughRADIO SET NO. 1 connector J1-R and switchS2C to RADIO TEST OUTPUT connector J18(E, fig. 5-2).

p. With RADIO TEST switch S2 set to 9, the

2-4 Change 5

band switch output signal from Radio SetAN/ARC- 114 under test is applied throughRADIO SET NO. 1 connector J1-S and switchS2C to RADIO TEST OUTPUT connector J18(E, fig. 5-2).

q. With RADIO TEST switch S2 set to 10, theantenna tuner test 1 to 5-MHz output signal fromthe radio set under test is applied throughRADIO SET NO. 1 connec tor J1-M anddeveloped across resistor R16. This signal isapplied through switch S2C to RADIO TESTOUTPUT connector J18 (E, fig. 5-2).

r. With RADIO TEST switch S2 set to 11, theantenna tuner test 5 to 10-M Hz output signalfrom the radio set under test is applied throughRADIO SET NO. 1 connec tor J1-W anddeveloped across resistor R17. This signal isapplied through switch S2C to RADIO TESTOUTPUT connector J18 (E, fig. 5-2).

s. The homing capabil i ty of Radio SetAN/ARC-114 can also be checked by themaintenance kit. The test setup is the same asdescribed in paragraph a above, except SIGNALOUTPUT LEFT connector J 13 is connectedthrough cable CG-3476/U to connector J3 on theAN/ARC-114, and the SIGNAL OUTPUTRIGHT connector J14 is connected throughanother cable CG-3476/U to connector J4 on theAN/ARC-114 (F, fig. 5-2). To perform thehoming tests, RADIO ANTENNA FUNCTIONswitch S 1 is operated as indicated below, withRADIO TEST switch S2 set to 8 (o above).

t. With RADIO ANTENNA FUNCTIONswitch S1 set to HOMING BALANCE, +28volts is applied to terminal Xl of homing balancerelays K2 (left) and K6 (right). A ground fromE15 is applied through TB3 to terminals X2 ofboth K2 and K6 (F, fig. 5-2). Both relays K2 andK6 energize with S1 set to HOMING BALANCE.The fm generator input at SIGNAL INPUTconnector J12 is applied through connector P4;coaxial adapters CP1 (9.5 db), CP8, and CP9;attenuator AT2 (12 db); adapter CP2; andconnector P9 and P6 to relays K2 and K6,respectively. With “both relays energized, iden-tical signal outputs are provided to Radio SetAN/ARC-114 through SIGNAL OUTPUT LEFTAND RIGHT connectors J13 and J14, respec-tively. Radio Set AN/ARC-114 provides thefollowing signals to the maintenance kit: thehoming signal adequacy signal is applied throughRADIO SET NO. 1 connector J1-A; a +28-voltsignal is applied through TB2-4 and connectorP2-X to HOMING/ADF/GYRO indicator;homing signal strength and its signal return areapplied through connectors J1-B and V, re-spectively; and homing right and left steeringsig-

nals are applied through connectors J1–T and U,respectively. Homing signals are applied toHeading-Radio Bearing Indicator ID-1351/Athrough connector P2 (G, fig. 5-2).

u. With RADIO ANTENNA FUNCTIONswitch S1 set to HOMING LEFT, relay K2 is en-ergized and relay K6 is deenergized (F, fig. 5-2). The fm generator input at SIGNAL INPUTconnector J12 is applied to SIGNAL OUTPUTLEFT AND RIGHT connectors J13 and J14,respectively. The signal is applied from connec-tor J12 through connector P4; coaxial adaptersCP1 (9.5 db), CP8, and CP9; attenuator AT2(12 db); adapter CP2; and connector P9, andthrough terminals B1 and B2 of energized relay

K2 to connector J13. The signal is applied fromconnector J12 through connector P4, coaxialadapters CP1 (9.5 db), CP4, CP5, attenuatorAT3 (15 db), adapter CP3, connector P7 andterminals B3 and B2 of deenergized relay K6 toconnector J14 (fig. 3–9). Since AT3 provides at-tenuation 3 db greater than AT2, the signal out-put at connector J14 is 3 db lower than the sig-nal output at connector J13.

v. With RADIO ANTENNA FUNCTIONswitch S1 set to HOMING RIGHT, relay K6 isenergized and relay K2 is deenergized (F, fig.5-2), The fm generator input at SIGNAL IN-PUT connector J12 is applied through the con-nectors, adapters, and attenuators identically asdescribed in u. above, except that with the ener-gization of both relays K2 and K6 reversed, theoutputs from adapters CP2 and CP3 to SIG-NAL OUTPUT LEFT and RIGHT connectorsJ13 and J14, respectively, are reversed and thesignal output at connector J13 is 3 db lower thanthe signal output at connector J14.

2-4. Communication Control Test CircuitAnalysis

(fig. 5-3 and 5-4)

a. The communication control tests are per-formed with the C–6533/ARC under test (commcent No. 2) connected to COMM CONT NO. 2connector J3. Also, the following pieces ofequipment are connected to the maintenance kit:one H–101A/U is connected to HEADSETS 1connector J15 through cable CX–10888/U. Asecond H-101A/U is connected to HEADSETS 2connector J16 through a second cable CX-10888/U; an audio generator is connected to COMMCONT TEST INPUT connector J19; and a mul-timeter is connected to COMM CONT TESTOUTPUT connector J20. For ease of explana-

TM 11-6625-928-35

tion, the C-6533/ARC that is contained in andpart of the maintenance kit is referred to ascomm cent No. 2.

b. The microphone amplifier test (fig. 5-3) isperformed with the selector switch on comm centNo. 2 and COMM CONT NO. 1 set to ICS (in-tercom). When HEADSETS 2 switch S7 isplaced at INTERCOM, a ground from E15 is ap-plied through TB3-6, 5, 4, 3 and 2; COMMCONT NO. 2 connector J3-M; cable CX-10893/AR; COMM CONT NO. 2 connector J1–M;connector J1–K; connector J3-K; closed contacts2 and 1 of switch S7; connector J3-E; and con-nector J1–E to the microphone intercom con-trol line. Application of the ground signal to theunit under test enables the switching circuitryand the microphone amplifier in comm cent No.2. Any audio input picked up by Headset-Micro-phone H–101A/U (microphone) connected toHEADSETS 2 connector J16 is applied to commcent No. 2 microphone amplifier, and amplifiedand applied to the switching circuitry (contain-ing an isolation network) in COMM CONT NO.1. The audio from the switching circuitry is am-plified by COMM CONT NO. 1 headset simpli-fier, and can be monitored on the associatedHEADSETS 1 Headset-Microphone H-101A/U(headset). Comm cent No. 2 microphone ampli-fier audio, which is indicated as the interphoneline signal at connector J1–DD, is appliedthrough COMM CONT NO. 2 connector J3-dto terminal board TB1–1 and developed acrossresistor R2 on assembly Al. With COMM CONTTEST switch S3 set to 1, microphone amplifieraudio output from the unit under test can bemonitored on the mult imeter connected toCOMM CONT TEST OUTPUT connector J20.

c. The headset amplifier test (fig. 5-4) is per-formed with the selector switches on comm centNo. 2 under test and COMM CONT NO. 1 setto ICS (intercom). With HEADSETS 1 switch S6set to INTERCOM, a ground is applied fromE15 through TB3-6, 5, 4 and 3; COMM CONTNO. 1 connectors J1-M and K; terminals 1 and2 of switch S6, and connector Jl-E to the switch-ing circuit of COMM CONT NO. 1 to enablethe microphone amplifier in COMM CONT NO.1. Audio applied to the microphone connected toHEADSETS 1 connector J15 is amplified by thismicrophone amplifier. The audio output line atTB1-1 is 150 ohms above ground (A1R2), andthe output line at TB2–10 is at ground. The au-dio output from COMM CONT NO. 1 micro-phone amplifier is applied through switching cir-cuit to the switching circuitry of comm cent No.

Change 3 2-5

TM 11-6625-928-35

2. The audio from this switching circuit is ampli-fied by its associated headset amplifier and ap-plied back through the maintenance kit andHEADSETS 2 connectors J16-B and D to theheadset. A multimeter connected to COMMCONT TEST OUTPUT connector J20 can moni-tor comm cent No. 2 headset amplifier audio withCOMM CONT TEST switch S3 set to 3, 4, 5, 6,7, 8, 9 or 10.

d. COMM CONT TEST switch S3 permits ad-ditional tests of the comm cent No. 2 under test.The following paragraphs discuss the circuit dif-ferences as switch S3 is rotated from one posi-tion to the next.

e. With COMM CONT TEST switch S3 set to1 or 2, the output of the audio generator con-nected to COMM CONT TEST INPUT connectorJ19 is applied to the microphone amplifier in theunit under test (fig. 5–3 ). The microphone am-plifier under test is enabled when HEADSETS 2switch S7 is held at INTERCOM. The output ofthe microphone amplifier can be monitored on amultimeter connected to COMM CONT TESTOUTPUT connector J20 only when switch S3 isset to 1. With COMM CONT TEST switch S3set to 2, HEADSETS 2 switch S7 held at TRANS-MIT and the selector switch on comm cent No.2 under test changed from ICS to 1, 2, 3, 4 or 5,the output from the microphone amplifier of theunit under test is applied to COMM CONTTEST OUTPUT connector J20. With switchS7 held at TRANSMIT, a ground from E15 isapplied through TB3-6, 5, 4, 3 and 2 to thecomm cent No. 2 under test through COMMCONT NO. 2 connector J3-M, cable CX-10893/AR, COMM CONT NO. 2 connector J1–M, con-nector J1–K, connector J3-K, closed contacts 2and 3 of switch S7, connector J3–B, and connec-tor J1–B to the microphone transmit control line.This ground activates a relay in the switching cir-cuit and enables the microphone amplifier. Theamplifier transmit audio output is applied toCOMM CONT NO, 2 connector J1–F, L, P, R orV, depending on the position of the selectorswitch of comm cent No. 2 under test. Theground applied to connector J1–B is reapplied,through an isolation diode in the unit under test,to connector J1-J, N, T, X or BB as the transmitsignal output to CONTROL SIGNAL light DS2,depending on the position of the comm cent No.2 selector switch. A ground appearing at one ofthese five pins causes CONTROL SIGNAL lightDS2 on the maintenance kit to light with COMMCONT TEST switdh S3 set to 2. COMM CONTTEST switch S3 positions 1 and 2 are used in

Change 3

conjunction with testing thefier and transmit audio andcomm cent No. 2 under test.

microphone ampli-control signals of

f. With COMM CONT TEST switch S3 set to 3,an audio generator output signal is appliedthrough COMM CONT TEST INPUT connectorJ19, switch S3A, cable CX-10893/AR, andCOMM CONT NO. 2 connector J3 to COMMCONT NO. 2 connectors J1-EE, KK, SS, FP,MM and UU of comm cent No. 2 under test (fig.5-4). With either comm cent No. 2 selectorswitch set to 1, 2, 3, 4 or 5, or comm cent No. 2receiver toggle switch 1, 2, 3, 4, or 5 set to ON,am input is applied to the headset amplifier. Toobtain an input at comm cent No. 2 connectorJ1-UU, the AUX switch on comm cent No. 2under test must be set to ON. The output fromthe audio generator is applied through theswitching circuit in comm cent No. 2 under testto the headset amplifier. The output of the head-set amplifier can be monitored on a multimeterconnected to COMM CONT TEST OUTPUTconnector J20 with COMM CONT TEST switchS3 set to 3, 4, 5, 6, 7, 8, 9 or 10. This output canalso be monitored on a headset connected toHEADSETS 2 connector J16.

g. With COMM CONT TEST switch S3 set to4, an audio generator output signal is appliedthrough COMM CONT TEST INPUT connec-tor J19, switch S3A, COMM CONT NO. 2 con-nector J3–h, cable CX–10893/AR, the commcent No. 2 connector J1–HH directly into theheadset amplifier (fig. 5-4). This input is ap-plied independently of any switch position onthe unit under test, The headset amplifier outputcircuit is the same as previously discussed in fabove.

h. Additional audio input circuits of comm centNo. 2 under test can be checked as the audio in-put is changed from comm cent No. 2 connectorJ1-HH to comm cent No. 2 connectors J1–WW,VV, DD, RR, LL and FF by rotating COMMCONT TEST switch S3 to 5, 6, 7, 8, 9 and 10, re-spectively (fig. 5–4 ). When the audio is appliedto comm cent No. 2 connector J1-WW or W,the NAV switch of comm cent No. 2 under testmust be set to ON if the output of the headsetsamplifier is to be monitored.

2-5. Automatic Direction Finder CircuitAnalysis

a. The automatic direction finder tests that areperformed using the maintenance kit require thatthe maintenance kit be inserted between connec-tor 1J2 on the adf receiver and connector 2J1 on

2-6

the automatic direction finder (adf) control. Testcable CX-10892/U connects the ADF RCVRTEST connector J5 to adf receiver connectorlJ2. A second test cable CX–10892/U connectsADF CONTROL TEST connector J6 to adf con-trol connector 2J1. ADF/GYRO connector J4must be connected to adf receiver connector lJ1(B, fig. 5-5). External test equipment connectedto maintenance kit ADF TEST RCVR connectorJ21 permits monitoring output signals of the adfreceiver. External test equipment connected tothe maintenance kit ADF TEST CONTROL con-nector J22 permits monitoring output signals ofthe adf control. The output signals applied toconnectors J21 and J22 for monitoring are se-lected by the ADF TEST switch. The adf senseantenna and the adf loop antenna inputs to theadf receiver must be connected to the mainte-nance kit as indicated in the chart below:

Adf receiverMaintenance kit connector connector

ADF SENSE ANTENNA J26 1J6ADF LOOP ANTENNA X J24 1J4ADF SENSE ANTENNA J26 1J5

b. An RF generator, connected to ADF SIG-NAL INPUT connector J23 (A, fig. 5-5), sup-plies the necessary input signals to the adf re-ceiver (sense, X-loop, or Y-loop antenna inputs)through the maintenance kit circuitry and testcables. ADF antenna function switch S5 controlsdistribution of the RF generator output to ADFLOOP ANTENNA X connector J24, ADFLOOP ANTENNA Y connector J25, and ADFSENSE ANTENNA connector J26 as follows:

(1) With ADF antenna function switch S5set to COMP, +28 volts is applied to energize re-lays K3, K4, and K5 (compass or antenna relay;compass, loop or X-relay; and compass, loop or Y-relay, respectively ). The input RF signal appliedto ADF SIGNAL INPUT connector J23 is ap-plied through connector P10 to coaxial adaptersCP14 and CP10. Two outputs from CP10 connec-tors P12 and P13 are applied to ADF LOOP AN-TENNA X and ADF LOOP ANTENNA Yconnators J24 and J25, respectively, throughclosed contacts of energized relays K4 and K5.The third output from coaxial adapter CP10 isapplied through coaxial adapters CP11, CP12,CP13, attenuator AT4, connector P11, and en-ergized relay K3 to ADF SENSE ANTENNAconnector J26. The output at this connector isattenuated 3 db more than the output at ADFLOOP ANTENNA X and ADF LOOP AN-TENNA Y connector J24 and J25, respectively.

TM 11-6625-928-35

The output at ADF SENSE ANTENNA connec-tor J26 is attenuated 3 db more than the outputsat ADF LOOP ANTENNA X connector J24,and ADF LOOP ANTENNA Y connector J25.

(2) With ADF antenna function switch S5set to ANT, relay K3 is energized and relays K4and K5 are deenergized. The RF generator out-put signal, applied through closed contacts B2and B1 of energized relay K3, is applied to theadf receiver through ADF SENSE ANTENNAconnector J26 and cable CG-3482/U. The RFgenerator output signal, applied through closedcontacts B2 and B3 of deenergized relays K4 andK5, is terminated with 51-ohm resistors R2 andR3, respectively.

(3) With ADF antenna function switch S5set to LOOP, relays K4 and K5 are energized andrelay K3 is deenergized. The RF generator out-put signal, applied through closed contacts B2and B1 of energized relays K4 and K5, is ap-plied to the adf receiver through ADF LOOPANTENNA X connector J24 and cable CG-3479/U, and ADF LOOP ANTENNA Y con-nector J25 and cable CG-3481/U respectively.The RF generator output signal, applied throughclosed contacts B2 and B3 of deenergized relayK3, is terminated with 51-ohm resistor R1.

(4) With ADF antenna function switch S5set to X, relay K4 is energized and relays K3 andK5 are deenergized. The RF generator outputsignal, applied through closed contacts B2 and B1of energized relay K4, is applied to the adf re-ceiver through ADF LOOP ANTENNA X con-nector J24 and cable CG-3479/U. The RF gen-erator output signal, applied through closed con-tacts B2 and B3 of deenergized relays K3 andK5, is terminated with 51-ohm resistors R1 andR3, respectively.

(5) With ADF antenna function switch S5set to Y, relay K5 is energized and relays K3 andK4 are deenergized, The RF generator output sig-nal, applied through closed contacts B2 and B1of energized relay K5, is applied to the adf re-ceiver through ADF LOOP ANTENNA Y com-nector J25 and cable CG–3481/U. The RF gen-erator output signal, applied through closed con-tacts B2 and B3 of deenergized relay K3, andK4 is terminated with 51-ohm resistors R1 andR2 respectively.

c. Transformer T1 receives 115-volt, 400-Hertz(Hz), single-phase power from the maintenancefacility through AC POWER connector J27 andAC POWER circuit breaker CB1 (B, fig. 5-5).

Change 3 2-7

TM 11-6625-928-35

The 26-volt, 400-Hz output on secondary termin-ah 5 and 9 of transformer T1 is available atADF TEST RCVR connector J21 for generalpurpose testing with ADF TEST switch S4 set to6. AC POWER indicator light DS1 lights whenAC POWER circuit breaker CB1 is set to ON.

d. With ADF TEST switch S4 set to 1, the+28-volt input applied through ADF RCVRTEST connector J5-A can be monitored on ADFTEST RCVR connector J21. This voltage is ap-plied to connector J21 through switch S4A . Thedc circuit is completed through ADF TESTswitch, S4B and connector J21-B to ground withswitch S4 set to 1, 8, 4 or 5. All pins in ADFRCVR TEST connector J5 connect to identicallylabeled pins in ADF CONTROL TEST con-nector J6. Lines can be connected through ADFTEST switch S4C to ADF TEST CONTROLconnector J22 for monitoring purposes. With theexception of ADF TEST switch S4 position 6 (cabove), the signals monitored on ADF TESTRCVR connector J21 are outputs of the adf re-ceiver. All signals monitored on ADF TESTCONTROL connector J22 are outputs of theadf control.

e. Any received audio from the adf receiver atADF/GYRO connector J4-A (B, fig. 5-5) isapplied to COMM CONT NO. 1 connector Jl-WW. The audio input line is 150 ohms aboveground (resistor A1R9) and may be monitoredon a headset connected to HEADSETS 1 connec-tor J15. To monitor this audio, the COMMCONT NO. 1 NAV switch must be set to ON.

f. Heading-Radio Bearing Indicator ID-1351/A, that is contained in and part of the mainten-ance kit, is used as an indicator during adf tests.Its operation and maintenance is covered in TM11-6605-202-12 and TM 11-5895-537-50. Out-put signals of the adf receiver are applied toHeading-Radio Bearing Indicator ID-1351/Athrough ADF/GYRO connector J4 and the wiringof the maintenance kit (B, fig. 5-5).

2-6. Interconnecting Box J-4247/AR CircuitAnalysis

The Interconnecting Box J-4247/AR constitutes apassive network which interconnects the AN/ARC-186(V) Radio Set variations with connector J 1 of theMK-994A/AR Test Facilities Kit.

2-8 Change 8

TM 11-6625-928-35

CHAPTER 3

DIRECT AND GENERAL SUPPORT MAINTENANCE

Section I. GENERAL TROUBLESHOOTING INFORMATION3-1. General InstructionsThe direct and general support maintenance pro-cedures in this chapter includes troubleshooting,repair, and testing procedures for Test Facilities KitMK-994/AR and MK-994A/AR. If CommunicationSystem Control C-6533/ARC, Heading-Radio BearingIndicator ID- 135 l/A, or Interconnecting Box J-4247/AR does not work, replace the defective unit.For repair of the C-6533/ARC, refer to TM 11-5821-262-35. For repair of the ID-1351/A, refer to TM 11-5895-537-50.

3-2. Organization of Troubleshooting Proceduresa. General. Perform troubleshooting by sectional-

izing a fault to a major operating section and thenlocalizing the fault to a defective assembly orcomponent.

b. Sectionalization and Localization. Sectionalizefaults by noting whether the fault occurred whileperforming radio, communication system control, oradf tests. Localize faults by referring to the trouble-shooting chart for the section of the maintenance kit inwhich the fault occurred (para 3-5).

c. Visuald inspection. Visually inspect the mainte-nance kit to see if faults can be sectionalized andlocalized without testing or measuring circuits.

ComponentCircuit breakers----------Selector switches---------

Cables (internal)---------Test cables--------------

Wir ing---- - - - - - - - - - - - - - -

Front panel- - - - - - - - - - - - -

Inspect forSecure mounting.Secure mounting, ease of opera-

tion.Proper connection.Broken connections or connec-

tors, shorted pins, or damagedpins.

Broken connections, charredinsulation (evidence of over-heating), poor solder connec-tions.

Evidence of physical damage orobliterated markings.

d. Procedure. After the trouble has been localized,replace the defective part or subassembly.

e. Intermittent troubles. Localize intermittent trou-bles, if present, by tapping or jarring the mainte-nance kit.

3-3. Test Equipment RequiredTest equipment, tools, materials, and facilities re-

quired for testing the maintenance kit are listed inparagraphs 3-9 and 3-10.

Caution: Be careful when making test equip-ment connections so that shorts will not be causedby exposed test equipment connectors. Tape orsleeve test prods or clips, as necessary, so as toleave only as much bare metal exposed as neededto make contact with the circuit under test.

3-4. Test Setup(fig. 3-18)

Caution: To avoid transistor and integratedcircuit damage, make sure that all power switchesare in the OFF position before changing cableconnections. Check the source voltage and polaritybefore making connections. Transistors and inte-grated circuits may be permanently damaged byimproper voltage or polarity. General support testson the maintenance kit require connection to twopower sources (115 volts, 400 Hz, and 28 volts)and to various test equipment. The 115-volt, 400-Hzpower source is only required when transformer T1is to be checked during adf test circuit tests (para3–16). Connect cable W23 between maintenancekit AC POWER connector J27 and the 115-volt,400-Hz power source. Connect cable W22 betweenmaintenance kit DC POWER connector J28 andthe 28-volt power source. Test equipment connec-tions vary from test to test.

3-5. Localizing Troublesa. General. When a record has been made of the

conditions under Which the maintenance kit wasfound to be malfunctioning, consult the appropriatetroubleshooting chart for information to localizethe trouble to a defective assembly or part. If amalfunction occurred during the radio tests, referto the radio test circuit troubleshooting chart (bbelow); during the communication control tests,refer to the communication system control testcircuit troubleshooting chart (c below); during theadf tests, refer to the adf test circuit troubleshootingchart (d below).

Note. The information presented in the following chartsis applicable when the COMM CONT NO. 1 VOL controlis adjusted for maximum audio gain.

Change 8 3-1

TM 11-6625-928-35

b. Radio Test Circuit Troubleshooting Chart (fig. 5-1 and 5-2).

Trouble symptom

1 + 27.5 volts not available at RADIOSET NO. 1 connector J1 or RADIOSET NO. 2 connector J2 with DCPOWER input circuit breaker CB2set to ON.

2 Tone not heard in HEADSETS 1Headset-Microphone H-101A/Uwith l audio input applied to RADIOSET NO. 1 connector J1- d.

3 No transmit audio output at RADIOSET NO. 1 connector J1-K. Audioinput to maintenance kit from Head-set-Microphone H-101A/U con-nected to HEADSETS 1 conneotorJ15, HEADSETS 1 switch S6 heldto TRANSMIT, and RADIO AN-TENNA FUNCTION switch S1 setto XCRV.

4 No transmit control output signal (grd)at RADIO SET NO. 1 connector Jl-hwith RADIO ANTENNA FUNC-TION switch S1 set to XCVR, andHEADSETS 1 switch S6 held toTRANSMIT.

5 Am or fm signal generator outputapplied to maintenance kit SIGNALINPUT connector J12 not presentor of improper amplitude, at T/RANTENNA connector J11 withRADIO ANTENNA FUNCTIONswitch S1 set to XCVR, and RADIOTEST switch S2 set to 1.

Change 6

a.

b.

c.

Probable trouble

Defective circuit breaker CB2.

Defective wiring.

Defective DC POWER connectorJ28, connector Jl, or connector J2.

d. Defective cable W22, W2, W3, W5,or W6.

a. Defective COMM CONT NO. 1.

b. Defective wiring.

c. Defective cable W20,W3, W5 or W6.

W21, W2,

d. Defective Headset-MicrophoneH-101A/U.

e. Defective HEADSETS 1 connector J15.a. Defective COMM CONT NO. 1.


c. Defective switch S6.

d. Defective switch S1.

e. Defective cable W20, W21, W2,W3, W5 or W6.

f . D e f e c t i v e r e l a y K l o rrelated diodes.

If transmit audio output is present atRADIO SET NO. 1 connector J1-K(Item No. 3), trouble is in switch-ing circuit of COMM CONT NO. 1,or associated wiring in maintenancekit.

a . See 3 f a b o v e .

b. Defective coaxial adapter CP1,CP6, or CP7. Defective attenuatorAT5.

c. Defective wiring.

Checks and corrective measures

a. Check continuity of circuit breakerCB2 and replace if necessary (fig.5-1).

b. Check continuity of associatedwiring and replace if necessary (fig.5-1).

c. Check continuity of connectors J28,Jl, and J2; replace if necessary(fig. 5-l).

d. Check continuity of cables W22,W2, W3, W5 and W6; replace ifnecessary (para 3-7p, b, and d).

a. Teat COMM CONT NO. 1 (para3-15) and replace CommunicationSystem Control C-6533/ARC ifnecessary.

b. Check continuity of associatedwiring l nd replace if necessary (C,fig. 5-2) .

c. Check continuity of cables W20,W21, W2, W3, W5 and W6. Replaceif necessary (para 3-7o, b, and d).

d. Check H-101A/U and replace ifnecessary (C, fig. 5-2).

e. Check continuity of connector J 15and replace if necessary (C, fig. !&2).

a. Test COMM CONT NO. 1 (para3-15) l and replace CommunicationSystem Control C-6533/ARC ifnecessary.

b. Check continuity of associatedwiring and replace if necessary(B, D, fig. 5-2).

c. Check continuity of switch S6and replace if necessary (B, fig.5-2).

d. Check continuity of switch S1and replace if necessary (B, fig.5-2) .

e. Check continuity of cable W20,W21, W2, W3, W5 and W6;replace if necessary (para 3-7o,b, and d).

f. Check relay/diodes,replace as required(fig. 3-0, 3 of5-2).

Check continuity from connectorPi-J, N, T and X to TB3-11.Check continuity between TB3-11and RADIO SET NO. 1 connectorJ1-h (B, fig. 5-2). If wiring is allright, replace Communication

a . See 3 f a b o v e .

b. perform teat given in paragraph3-14c, steps 2 and 3 to isolatetrouble. Relpace if necessary (A,fig. 5-2) .

c. Check continuity of associatedwiring l nd replace if necessary (Aand B, fig. 5-2).

3 - 2

I t e mNo.

System Control C-6533/ARC.

Troubles symptom

6 Unable to monitor output power ofradio set under test with externalwattmeter connected betweenPOWER METER INPUT con-nector J10 and POWER METEROUTPUT connector J9.

7 Unable to monitor X-mode guardreceiver output signal at RADIOTEST OUTPUT connector J18 withsignal applied to RADIO SET NO. 1connector J1-b, and RADIO TESTswitch S2 set to 1.

TM 11-6625-928-35

Probable trouble Checks and corrective measures

a . S e e 3 f a b o v e . a . S e e 3 f a b o v e .

b. Defective wiring. b. Check continuity of associatedwiring and replace if necessary (Aand B, fig. 5-2).

c. Defective cable W10 or W11. c. Check continuity of cable W10 andW 11. Replace if necessary (para3-70 and h).

d. Defective attenuator AT1. d. Perform teat given in paragraph3-14c, step 2. Replace attenuatorAT1 if necessary (A, fig. 5-2).

a. Defective switch S2. a. Check continuity of switch S2 andreplace if necessary (E, fig. 5-2).

b. Defective wiring. b. Check continuity of associatedwiring and replace if necessary (E,fig. 5-2) .

c. Defective cable W2, W3, W5 or W6. c. Check continuity of cables W2, W3,

8 Unable to monitor retransmit audio a. Defective switch S2.output signal at RADIO TESTOUTPUT connector J18 with audio b. Defective wiring.signal applied to RADIO SET NO. 1connector J1-X, and RADIO TESTswitch S2 set to 2. c. Defective cable W2, W3, W5 or

W6.

9 CONTROL SIGNAL light DS2 does a. Dcfective CONTROL SIGNALnot light when retransmit control light DS2.output signal (grd) is applied toRADIO SET NO. 1 connector J1-H b. Defective switch S2.with RADIO TEST switch S2 set to2. c. Defective wiring.

10 X-mode control signal at RADIO SET a. Defective switch S2.NO. 1 connector J l-g is not atground level with RADIO TEST b. Defective wiring.switch 82 set to 3.

c. Defective cable W2, W3, W5, orW6.

11 Unable to monitor X-mode receive out- a. Defective switch S2.put signal at RADIO TEST OUT-PUT connector J18 with signal b. Defective wiring.l pplied to RADIO SET NO. 1 con-nector J l-c and RADIO TESTswitch S2 in position 3. c. Defective cable W2, W3, W5, or

W6.

12 Unable to monitor retransmit audio at a. Defective switch S2.RADIO SET NO. 1 connector J1-Yor RADIO SET NO. 2 connector b. Defective wiring.J2-X with RADIO TEST switch S2set to 4 and audio generator signall pplied to RADIO TEST INPUT c. Defective cable W2, W3, W5, orconnector J17. W6.

W5 and W6; replace if neceesary(para 3-7b and d).

a. Check continuity of switch S2 andreplace if necessary (E, fig. 5-2).

b. Check continuity of associatedwiring and replace if necessary (E,fig. 5-2) .

c. Check continuity of cable W2,W3, W5 and W6; replace if neces-sary (para 3-7b and d).

a. Check CONTROL SIGNAL lightDS2 and replace if necessary (E,fig. 5-2) ,

b. Check continuity of switch S2 andreplace if necessary (E, fig. 5-2).

c. Check continuity of associatedwiring and replace if necessary (E,fig. 5-2).


b. Check continuity of associatedwiring and replace if necessary(E, fig. 5-2).

c. Check continuity of cables W2, W3,W5, and W6; replace if necessary(para 3-7b and d).







Change 6 3-3

I t e mN o .

TM 11-6625-928-35

13 Radio set under test does not switch totransmit mode of operation withRADIO TEST switch S2 set to 4and RADIO ANTENNA FUNC-TION switch S1 set to XCVR.

14 X-mode transmit audio not presentat RADIO SET NO. 1 connectorJ1-J with RADIO TEST switch S2set to 5, and audio generetor signalapplied to RAD1O TEST INPUTconnector J 17.

15 Unable to disable tone modulation inRadio Set AN/ARC-114 withRADIO TEST switch S2 set to 5.

16 Unable to monitor received audio signalat RADIO TEST OUTPUTconnector J18 with audio signalapplied to RADIO SET NO. 1connector Jl-d, and RADIO TESTswitch S2 set to 6.

17

18

Guard receiver agc test signal orreceiver agc test signal (both + 6.8± 0.5-volt levels) not present atRADIO SET NO. 1 connectorJ1-G with RADIO TESTswitch S2 set to 7, andnot present at J1-F withRADIO TEST switch S2set to 5.

Unable to monitor homing enableoutput signal at RADIO TESTOUTPUT connector Jl8 withsignal applied to RADIO SETNO. 1 connector J1-R, andRADIO TEST switch S2 set to 8.

19 Unable to monitor band switch signalfrom Radio Set AN/ARG-114 atRADIO TEST OUTPUT connectorJill with signal applied to RADIOSET NO. 1 connector J1-S, andRADIO TEST switch S2 set to 9.

Probable trouble

o. Defective relay K1.

b. Defectivc switch S2.


d. Defective wiring.

e. Defective cable W2, W3, W5, orW6.

o. Defective switch S2.


c. Defective cable W2, W3, W5 or

a .

b .

c .

d .

a .

b .

e.

W6.

Defective relay K7.

Defective switch S2.

Defective wiring.

Defective cable W2 or W3.

Defective switch 82.

Defective wiring.

Defective cable W2 W3, W5 orW6.

a. Defective redidtor R15 or diodeCR1 on assembly Al.

b. Defective switch S2.


d. Defective cable W2, W3, W5 orW6.

a. Defective switch S2.


c. Defective cable W2, W3, W5 orW6.



c. Defective cable W2 or W3.

a.

b.

c.replace if necessary (B, fig. 5-2).

d. Check continuity of associatedwiring and replace if necessary (Band E, fig. 5-2).

e. Check continuity of cables W2, W3,W5, and W6; replace if necessary(para 3-7b and d).



c. Check continuity of cable W2, W3,W5 and W6; replace if necessary(para 3-7b and d).

a. Check relay K7 and replace ifnecessary (E, fig. 5-2).

b. Check continuity of switch S2 andreplace if necessary (E, fig. 5-2),


d. Check continuity of cable W2 orW3; replace if necessary (para 3-7b)


b. Check continuity of associatedwiring and replace if necessary (E,fig. 5-2).

c. Check continuity of cable W2,W3, W5 and W6; replace if necessary(para 3-7b and d).

a. Check R15 and CR1 on Al andreplace if necessary (E, fig. S2).

b. Check continuity of switch S2 andreplace if necessary (E, fig. 5-2).


d. Check continuity of cables W2,W3, W5 and W6; replace if necessary(para 3-7b and d).

a. Check continuity of switch S2and replace if necessary(E, fig. 5-2).


c. Check continuity of cables W2,W3, W5 and W6; replace if necessary(para 3-7b and d).



c. Cheek continuity of cable W2 orW3; replace if necessary (para3-7b).

Check relay K1 and replace ifnecessary (B, fig. 5-2)Check continuity of switch S2 andreplace if necessary (B adn E, fig.5-2).check continuity of switch S1 and


3 - 4 Change 5

I t e mNo. Trouble symptom

TM 11-6625-928-35

c. Radio Test Circuit Troubleshooting Chart (fig. 6-1 and S-2) (cent).

I t e w N o . Troub le symptom

20 Unable to monitor antennatuner test 1-5 MHz signalfrom RADIO TEST OUT-PUT connector J18 withsignal applied to RADIOSET NO. 1 connectorJ1-M and RADIO TESTswitch S2 set to 10.

21 Unable to monitor antennatuner test 6-10 MHzsignal from RADIO TESTOUTPUT connector J18with signal applied toRADIO SET NO. 1 con-nector J1-W and RADIOTEST switch S2 set to 11.

22 Unable to monitor X-mode transmit audioat J1-J when RADIOTEST switch S2 set

to 3.

23 Cannot test AN/ARC-186(V)Radio Set

a .

b .

c .

a.

b .

c .

Probable trouble


Defective wiring.

Defective cable CX-10889/U orCX-ll985/AR.


Defective wiring.

Defective cable CX-l0889/U orCX-11985/AR.

a . Defective wiring orunaltered test set.

b . Defective switch S2.

a. Defective Interconnecting BoxJ-4247/AR.

a.

b.

c.

a.

b.

c.

a .


Check continuity of switch S2and replace if necessary (E,fig. &2).Check continuity of associatedwiring and replace if necessary(E, fig. s-2).Check continuity of cable CX-l0889/U and/or CX-11985/AR.Replace if necessary (para3-7b and u).

Check continuity of switch S2and replace if necessary (E,fig. 5-2).Check continuity of associatedtiring and replace if necessary(E, fig. 5-2).Check continuity of cables CX-10889/U and/or CX-l1985/AR.

b .

a.

b.

Replace if necessary3-7b and u).

Check wiring (B, fig.

5-2), repair as re-quired.

(para

Check for jumper be-

tween S2A-3 and S2A-

5; repair as required.

Change 8 3-4.1

b. Defective Mk-994/AR.

Check contnuity of J-4247/AR(para. 3-17). Repair/replace defective com-ponents as required.Check Mk-994/AR (para. 3-13 through3-16). Repair/replace defective com-ponents as required.

TM 11-6625-928-35

3-4.2 Change 6

Figure 3-0. Chassis, viewed from right edge, altered for use with RT-1167/ARC-164(V)

EL2GF001NOTE- R4 AND R5 ADDED BY MWO 11-6625-928-40-1,CR1 QND CR2 ADDED

TO INCREASE COMPATABILITY WITH RT-1167/ARC-164(V)

TM 11-6625-928-35

c. Communication System Control Test Circuit Troubleshooting Chart (fig. 5-1, 5-3, and 5-4).

Trouble symptom

1 +27.5 volts not available at COMMCONT NO. 2 connector J3 withwith DC POWER input circuitbreaker CB2 set to ON.

2 Sound not heard in Headset-Micro-phone H–101A/U (headset), con-nected to HEADSETS 1 connectorJ15, with an audio input applied toHeadset-Microphone H-101A/U(microphone), connected to HEAD-SETS 2 connector J16, and HEAD-SETS 2 switch S7 set to INTER-COM.

3 Sound not heard in Headset-Micro-phone H-101A/U (headset), con-nected to HEADSETS 2 connectorJ16, with an audio input applied toHeadset-Microphone H-101A/U(microphone), connected to HEAD-SETS 1 connector J15, and HEAD-SETS 1 switch S6 set to INTER-COM.

4 With COMM CONT TEST switch S3set to 1, HEADSETS 2 switch S7set to INTERCOM, and a referenceaudio oscillator signal applied toCOMM CONT TEST INPUTconnector J19, internal microphoneamplifier signals in C-6533/ARCunder test are missing, or below,minimum tolerances.

5 With COMM CONT TEST switchS3 set to 2, HEADSETS 2 switchS7 set to TRANSMIT, and a l-kHzsignal of 0.6-volt rms amplitudeapplied to COMM CONT TESTINPUJT connector J19, output atCOMM CONT TEST OUTPUTconnector J20 is below 2.75 voltsrms. H-l01A/U i s c o n n -e c t e d t o H E A D S E T S 2

connector J16 by cableCX-10888/U. Disconnect

H-101A/U or CX-l0888/Uwhen applying signal toconnector J19.

Probable trouble

a. Defective circuit breaker CB2.


c. Defective DC POWER connectorsJ28 or connector J3.

d. Defective cable W22.

a .

b .

c .

d .

a .

b .

c .

d .

a .

b .

c .

d .

a.

b .

c .

d .

Defective COMM CONT NO. 1.


Defective wiring.

Defective cable W9, W20, or W21

Defective COMM CONT NO. 1.


Defective wiring.


a. Check continuity of circuit breakerCB2 and replace if necessary (fig.5- l ) .

b. Check continuity of associatedwiring and replace if necessary (fig.5-l).

c. Check continuity of connectorsJ28 and J3 and replace if necessary(fig. 5-l).

a

b.

c.

d.

Test COMM CONT NO. 1 and re-place Communication System Con-trol C-6533/ARC if necessary(para 3-15).Check continuity of switch S7 andreplace if necessary (fig. 5-3).Check continuity of associated wiringand replace if necessary (fig. 5-3).Check continuity of cables W9,W20, and W21; replace if necessary(para 3-7f and o).

a. Test COMM CONT NO. 1 andreplace Communication SystemControl C-6533/ARC if necessary(para 3- 15).

b. Check continuity of switch S6 andreplace if necessary (fig. 5-4).

c. Check continuity of associatedwiring and replace if necessary(fig. 5-4) .

Defective cable W9, W20; or W21. d. Check continuity of cables W9,W20, and W21; replace if necessary(para 3-7f and o).

Defective switch S7. a. Check continuity of switch S7and replace if necessary (fig. 5-3).

Defective switch S3. b. Check continuity of switch S3and replace if necessary (fig. 5-3).

Defective wiring. c. Check continuity of associatedwiring and replace if necessary(fig. 5-3).

Defective cable W9. d. Check continuity of cable W9 andreplace if necessary (para 3–7f).

Defective switch S7. a. Check continuity of switch S7 and

Defective switch S3. b.

Defective cable W9. c.

Defective wiring or resistor R2. d.

e.

rcplace if necessary (fig. 5-3).Check continuity of switch S3 and

replace if necessary (fig. 5-3).Check continuity of cable W9 andreplace if necessary (Pam 3–7f).Check R2 and continuity of

associatcd wiring; replace ifnecessary (fig. 5–3).Disconnect H-101A/U W20 orW21 when applying signal toconnector J 19.

Change 3 3 - 5

I t e mN o .

d. C h e c k c o n t i n u i t y o fcable CX-10886/AR andreplace if necessary(para. 3-7p).

TM 11-6625-928-35

ItemNo. Trouble symptom Probable trouble

a. Defective light DS2.

b. Defective switch S3.




6 With COMM CONT TEST switch S3set to 2, and HEADSETS 2 switchS7 set to TRANSMIT, CONTROLSIGNAL light DS2 fails to light.

a. Check light DS2 and replace ifnecessary (fig. 5-3).

b. Check continuity of switch S3 andreplace if necessary (fig. 5-3).

c. Check continuity of switch S7 andreplace if necessary (fig. 5-3).

d. Check continuity of associatedwiring and replace if necessary(fig. 5-3).

e. Check continuity of cable W9 andreplace if necessary (para 3-7f).

e. Defective cable W9



7 With COMM CONT TEST switch S3set to 3, Headset-MicrophoneH-101A/U (headset) connected toHEADSETS 2 connector J16, al-k Hz signal of 2.7.5 volts rmsamplitude applied to COMMCONT TEST INPUT connectorJ19, and COMM CONT NO. 2selector switch rotated to 1, 2, 3, 4,and 5, no l-k Hz audio tone is heardin Headset-Microphone H-101A/U(headset).

8 With COMM CONT TEST switch

a. Check continuity of switch S3 andreplace if necessary (fig. 5-4).

b. Check continuity of associatedwiring and replace if necessary(fig. 5-4).

c. Check continuity of cable W9 andreplace if necessary (para 3–7f).

c. Defective cable W9.



a. Check continuity of switch S3 andreplace if necessary (fig. 5–4 ).

b. Check continuity of associatedwiring and replace if necessary(fig. 5-4).

c. Check continuity of cable W9 andreplace if necessary (para 3-7f).

S3 set to 3, 4, 5, 6, 7, 8, 9, or 10,Headset-Microphone H-101A/Uconnected to HEADSETS 2 con-nector J16, and a l-k Hz signal of2.75-volt rms amplitude appliedto COMM CONT INPUT con-nector J19, no l-k Hz audio tone isheard in Headset-MicrophoneH-101A/U (headset).

c. Defective cable W9.

Note. COMM CONT NO. 2 AUX and NAV switches set to ON for COMM CONT TEST

Adf Test Circuit Troubleshooting Chart (fig. 5-l and 5-5).

switch S3 posi t ions 3, 5, and 6.

d.

1 +27.5 volts not available atGYRO connector, J4.

Probable trouble

Defective DC POWER inputcircuit breaker CB2.Defective wiring.


a. Check circuit breaker CB2 andreplace if necessary (fig. 5-1).

b. Perform voltage and continuitychecks on associated wiring andreplace if necessary (fig. 5-1).

c. Check continuity of cable W22;replace if necessary (para 3-7p).

a. Check continuity of circuit breakerCB1 and replace if necessary (B,fig. 5-5) .

b. Perform voltage and continuitychecks on associated wiring andreplace if necessary (B, fig. 5-5).

c. Perform voltage and resistancechecks on transformer T1 andreplace if necessary (fig. 5-6).

d. Check continuity of switch S4 and

Trouble symptom

ADF/ a.

b.

c. Defective interconnecting cableW22.Defective AC POWER input

circuit breaker CB1.2 26 volts rms, 400 Hz not available at a .

ADF TEST RCVR connector J21with ADF TEST switch S4 set to 6.


Defective transformer T1.c.

d. Defective switch S4.replace if necessary (B, fig. 5-5).Check continuity of cable W23 andreplace if necessary (para 3-7d).Check continuity of associatedwiring and replace if necessary (B,fig. 5-5) .Check continuity of cables W4,W7, and W8. Replace if necessary(para 3-7c and e).

Defective interconnecting cableW23.Defective wiring.

e. e.

a.

b.

3 Absence of either of following signals a .at ADF/GYRO connector J4:

26 volts rms, 400 Hz.Audio output. b. Defective interconnecting cable

W4, W7, or W8.

Change 33 - 6

I temNo.

TM 11-6625-928-35

ItamProbable trouble

Defective wiring.

Checks and corrective measuresNo. Trouble symptom

Check continuity of associatedwiring and replace if necessary (B,fig. 5-5).Check continuity of cables W4,W7, and W8. Replace if necessary(para 3-7c and e).

Check continuity of associated wir-ing and replace if necessary (B, fig.5-5) .Check continuity of cables W4, W7,and W8; replace if necessary (para3-7c and e).Check continuity of switch S4 andreplace if necessary (B, fig. 5–5).

4 .

5

Absence of any one of following signalsat ADF RCVR TEST connector J5:

+28 volts.+15 volts regulated.Tuning meter input

a .

b .

a .

b .

c .

a

b .

c .

a

b

c .

d .

a .

b .

a .

b .

c .

a.

b.

c .

a .

b .

a .

b .

c .

a

b .

c .

Defective interconnecting cableW4, W7, or W8.

Absence of any one of following sig-nals, at ADF TEST RCVR con-nector J21 with ADF TEST switchS4 in position shown:

SwitchS4pos Signal

1 +28 volts.2 26 volts rms, 400 Hz.3 +15 volts regulated.4 Tuning meter i n p u t5 Audio output.

Absence of radio bearing meter indi-cation on HOMING/ADF/CYROindicator.

Defective wiring.



Test ID–1351/A and replace if nec-essary (para 3– 16c, step 3).Check continuity of associated wir-ing and replace if necessary (B, fig.5-5) .Check continuity of cables W4, W7,

Defective Heading-Radio BearingIndicator ID-1351A.Defective wiring.

6

7

Defective interconnecting cableW4, W7, or W8. and W8; replace if necessary (para

3-7c and e).a. Test COMM CONT NO. 1 (para

3-15) and replace CommunicationSystem Control C-6533/ARC ifnecessary.

b. Check continuity of associated wir-

Defective COMM CONT NO. 1.Unable to hear audio tone in Headset-Microphone H-101A/U (headset)connected to HEADSETS 1 con-nector J15 with audio signal presentat ADF TEST RCVR connectorJ21, ADF TEST switch S4 set to 5,and COMM CONT NO. 1 receivermonitor switch NAV set to ON.

Defective wiring.ing and replace if necessary (B, fig.

c.5-5) .Check continuity of cable W20 orW21 and replace if necessary (para3-70).Check H-101A/U and replace if

necessary.Check continuity of associated wir-

ing and replace if necessary (B, fig.5-5).Check continuity of cables W4,W7, and W8; replace if necessary(para 3-7c and e).

Defective interconnecting cableW20 or W21.

Defective Headset-MicrophoneH-101A/U (headset).Defective wiring.

d.

a.Absence of any one of following sig-nals at ADF CONTROL TEST

8

9

connector J6:28 volts, switched, pin B+15 volts, pin F.+15 volts, pin L.+15 vo1ts, pin M.+15 volts, pin S.

Gain control output.Absence of any one of following

signals at ADF TEST CONTROLconnector J22 with ADF TESTswitch S4 in position shown:


b.

a. Check continuity of associatedwiring and replace if necessary(B, fig. 5-5).Check continuity of cables W4,W7, and W8; replace if necessary(para 3-7c and e).Check continuity of switch S4 and

Defective wiring.



b.

Signal

1 +28 volts, pin B.2 +15 volts, pin F.3 +15 volts, pin L.4 +15 volts, pin M.5 +15 volts, pin S.6 Gain control output.

RF test signal is not present atSENSE ANTENNA connector J26with ADF antenna function selectorswitch S5 set to ANT or COMP.

c.replace if necessary (B, fig. 5-5).

1 0 Defective capacitor C 1.

Defective relay K3.

Defective attenuator AT4.

a. Check capacitor Cl and replace ifnecessary (A, fig. 5-5).

b. Check relay K3 and replace ifnecessary (A, fig. 5–5).

c. Check attenuator AT4 and replaceif necessary (A, fig. 5-5).

Change 3 3-7

SwitchS 4

p o s

TM 11-6625-928-35

Trouble symptom

11 RF tent signal is not present at ADFLOOP ANTENNA X connector J24with ADF antenna function selectorswitch S5 set to X, LOOP, orCOMP.

12 RF teat signal is not present at ADFLOOP ANTENNA Y connectorJ25 with ADF antenna functionselector switch S5 set to Y, LOOP,or COMP.

Probable trouble


e. Defective switch S5.

f. Defective interconnecting cableW15 or W18.

a. Defective capacitor C2.

b. Defective relay K4.



e. Defective interconnecting cableW15 or W16.

a. Defective capacitor C3.

b. Defective relay K5.



e. Defective interconnecting cableW15 or W17.


d. Perform voltage and continuitychecks on associated wiring andreplace if necessary (A, fig. 5-5).

e. Check continuity of switch S5 andreplace if necessary (A, fig. 5-5).

f. Check continuity of cables W15and W18; replace if necessary(para 3-7j and 3-7m).

a. Check capacitor C2 and replace ifnecessary (A, fig. 5-5).

b. Check relay K4 and replace ifnecessary (A, fig. 5-5).

c. Perform voltage and continuitychecks on associated wiring andreplace if necessary (A, fig. 5-5).

d. Check continuity of switch S5 andreplace if necessary (A, fig. 5-5).

e. Check continuity of cables W15and W16 and replace if necessary(para 3-7j and 3-7k).

a. Check capacitor C3 and replace ifnecessary (A, fig. 5-5).

b. Check relay K5 and replace ifnecessary (A, fig. 5-5).

c. Perform voltage and continuitychecks on associated wiring andreplace if necessary (A, fig. 5-5.

d. Check continuity of switch S5 andreplace if necessary (A, fig. 5-5).

e. Check continuity of cables W 15 andW 17. Replace if necessary (para3-7j and l).

I t e mNo.

3 - 8 Change 3

TM 11-6625-928-35

Figure 3-1. Chassis, viewed from panel right edge.

Change 5 3-9

Figure 3-2. Chassis, rear v i e w

3-10 Change 5

TM 11-6625-928-35

Figure 3-3. Chassis, oblique view from panel bottom edge.

Change 5 3-11

3-12 Change 5

TM 11-6625-928-35

Figure 3-4. Chassis, viewed from panel top edge.

TM 11-6625-928-35

Figure 3-5. Chassis, viewed from panel bottom edge.

Change 5 3-13

TM 11-4425-928-35

Figure 3-6. Chassis, viewed from panel left edge.

3-14 Change 5

TM 11-6625-928-35

Figure 3-7. Chassis, viewed from panel top edge with ID-1351/A and MP104 removed.

Change 5 3-15

TM 11-6625-928-35

3-16

Figure 3-8. Chassis, viewed from panel left edge with ID-1351/A and MP104 removed.

Change 5

Figure 3-9.

TM

11-6625-928-35

Ch

ang

e 53-16.1

TM 11-6625-928-35

Figure 3-10. Adf coaxial fittings, exploded view.

3-16.2 Change 5

TM 11-6625-928-35

3-16.3Change 3

Figure 3-11. Assembly instructions for type BNC RF cable connectors.

TM 11-6625-928-35

3-16.4 Change 3

Figure 3-12. Assembly instructions for type N RF cable connectors.

TM 11-6625-928-35

3-16.5Change 3

Figure 3-13. Assembly instructions for type TPS RF cable connectors.

TM 11-6625-928-35

3-16.6 Change 3

Figure 3-14. Assembly instructions for type DM RF cable connectors.

TM 11-6625-928-35

3-16.7Change 3

Figure 3-15. Assembly instructions for RF cable connector SM-A-595802-2.

TM 11-6625-928-35

3-16.8 Change 7 (Next Numbered Page is 3-25)

Figure 3-16. Assembly instructions for RF cable connector SM-A-595804-6.

TM 11-6625-928-35

Section Il. REPAIRS

3-6. General Parts Replacement Techniques

a. All parts on the chassis and panel of themaintenance kit are easily replaced without spe-cial procedures. Figures 3-1 through 3-10, 5-8and 5-9 show the location and orientation ofparts on the chassis. Wiring information for re-pairing cables given in paragraph 3-7.

b. To prevent damage to components of themaintenance kit, use a pencil-type soldering ironwith a 25-watt maximum capacity. If the ironpower source is ac power, use an isolating trans-former between the iron and the line. Do not usea soldering gun; damaging voltages can be in-duced in components.

c. The following tools from the MK–1191/ARshould be used in the repair of maintenance kitconnectors:

Tool Use

Adapter, Crimp MS3191-1 Crimps pins or sockets oncable wires.

Tool, Extractor CET 20A Extracts size 20 pins orsockets from connectors.

Tool, Extractor CET 16 Extracts size 16 pins orsockets from connectors.

Tool, Insertion CIT 20 Inserts size 20 pins orsockets in connectors.

Tool, Insertion CIT 16 Inserts size 16 pins orsockets in connectors.

3-7. Cable Wiringa. Cable CG-3475/U. Cable CG3475/U (W1)

consists of 6 feet of RG-188A/U. The coaxialcable is terminated with right-angle female plugP1 (fig. 3-15) and male BNC plug P2 (fig. 3-11).

b. Cable CX-10889/U. Cable CX-10889/U(W2 or W3) is a 32-wire, rubber-insulated cableterminated with multi-pin plugs P1 and P2.

c. Cable CX-10890/U. Cable CX-10890/U(W4) is a 15-wire, rubber-insulated cable withmultipin plugs P1 and P2.

d. Cable CX-10891/U. Cable CX-10891/U(W5 or W6) is a 32-wire rubber-insulated cablewith multipin plugs P1 and P2.

Change 3 3 - 2 5

TM 11-6625-928-35

e. Cable CX-10892/U. Cable CX-10892/U(W7 or W8) is a 19-wire, rubber-insulated cablewith multipin plugs P1 and P2.

f. Cable CX-10893/AR. Cable CX-10893/AR (W9) is a 40-wire, rubber, insulated cablewith multipin plugs P1 and P2.

3-26 Change 3

g. Cable CG-3477/U (fig. 8-11 and 3-12). Ca-ble CG-3477/U (W10) consists of 4 feet of RG-58C/U coaxial cable with male type BNC plugP1 and female type N jack P2 Connector P1 isUG-88E/U. The manufacturer's (Amphenol)part number for P2 is 35025.

h. Cable CG-2340A/U (fig. 3-11 and 3-12).Cable CG-2340A/U (W11) consists of 4 feet of

RG-58C/U coaxial cable with male type BNCplyg P1 and male type N plug P2. Connector P1is UG-88E/U. Connector P2 is UG-536B/U.

i. Cable CG-3476/U (fig. 3-13). Cable CG-3476/U (W12, W13, or W14) consists of 4 feetof RG-58C/U coaxial cable with male type TPS

plugs P1 and P2. Connectors P1 and P2 are UG-1366/U.

j. Cable CG–3478/U (fig. 3–11). Cable CG-3478/U (W15) consists of 4 feet of RG-58C/Ucoaxial cable with male type BNC plugs P1 andP2. Connectors P1 and P2 are UG-88E/U.

k. Cable CG-8479/U (fig. 3-14). Cable CG-3479/U (W16) consists of 4 feet of RG-58C/Ucoaxial cable with female type DM plugs P1 andP2. The manufacturer’s (Dage Electric Co., Inc. )part number for P1 and P2 is 6388–1.

l. Cable CG–3481/U (fig. 3–14). Cable CG-3481/U (W17) consists of 4 feet of RG-58C/Ucoaxial cable with female type DM plugs P1 andP2. The manufacturer’s (Dage Electric Co., Inc. )part number for P1 and P2 is 6390–1.

m. Cable CG–3482/U (fig. 3–14). Cable CG–3482/U (W18) consists of 4 feet of RG–58C/Ucoaxial cable with male type DM plugs P1 andP2. The manufacturer’s (Dage Electric Co., Inc. )part number for P1 and P2 is 6391–1.

n. Cable CG-3480/U. (fig. 8–14). C a b l eCG–3480/U (W19) consists of 4 fe

TM 11-6625-928-35 · Communication System Control C-6533/ARC (part of MK-994/AR). Communication...

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