31R4-2FRN45-2-33JG-1.pdf

TO 31R4-2FRN45-2-33JG-1

1 SEPTEMBER 2003 Change 4 8 FEBRUARY 2012

TECHNICAL MANUAL

JOB GUIDE

ORGANIZATIONAL MAINTENANCE

TACAN NAVIGATIONAL SET

AN/FRN-45

PN 880199

DISCLOSURE NOTICE – This information is furnished upon the condition that it will not be released to another nation without the specific authority of the Department of the Air Force of the United States, that it will be used for military purposes only, that individual or corporate rights originating in the information, whether patented or not, will be respected, that the recipient will report promptly to the United States, any known or suspected compromise, and that the information will be provided substantially the same degree of security afforded it by the Department of Defense of the United States. Also, regardless of any other markings on the document, it will not be downgraded or declassified without written approval of the originating United States agency.

DISTRIBUTION STATEMENT D - Distribution authorized to Department of Defense and U.S. DoD contractors only. Due to critical technology (8 February 2012). Other requests for this document shall be referred to OC-ALC/GKAAB, Tinker AFB, Oklahoma 73145-9155.

WARNING - This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C. 2751 et seq.) or Executive Order 12470. Violations of these export laws are subject to severe criminal penalties. Disseminate in accordance with provisions of DoD Directive 5230.25.

HANDLING AND DESTRUCTION NOTICE - Handle in compliance with distribution statement and destroy by any method that will prevent disclosure of the contents or reconstruction of the document.

PUBLISHED UNDER THE AUTHORITY OF THE SECRETARY OF THE AIR FORCE

*Zero in this column indicates an original page

A Change 4 USAF

NOTE: The portion of the text affected by the change is indicated by a vertical line in the outer margins of the page. Changes to illustrations are indicated by miniature pointing hands. Changes to wiring diagrams are indicated by shaded or screened areas.

TOTAL NUMBER OF PAGES IN THIS MANUAL IS 206, CONSISTING OF THE FOLLOWING:

Title A i - ix x Blank 1-1 - 1-2 1-3 - 1-4 2-1 - 2-3 2-4 Blank 3-1 - 3-3 3-4 3-5 - 3-7 3-8 3-9 3-10 3-11 3-12 3-13 - 3-15 3-16 Blank 3-17 - 3-21 3-22 Blank 3-23 3-24 - 3-25 3-26 3-27 3-28 3-29 - 3-31 3-32 3-33 3-34

3-35 3-36 3-37 3-38 3-39 3-40 Blank 3-41 3-42 - 3-43 3-44 3-45 3-46 Blank 3-47 - 3-49 3-50 Blank 3-51 - 3-53 3-54 3-55 3-56 Blank 3-57 - 3-71 3-72 Blank 3-73 3-74 Blank 3-75 3-76 3-77 - 3-81 3-82 3-83 - 3-95 3-96 - 3-98 3-99 - 3-105 3-106 Blank

4-1 - 4-7 4-8 Blank 4-9 - 4-13 4-14 Blank 4-15 - 4-17 4-18 Blank 4-19 - 4-21 4-22 Blank 4-23 4-24 4-25 - 4-26 5-1 - 5-5 5-6 Blank 5-7 5-8 Blank 5-9 - 5-11 5-12 Blank 5-13 - 5-17 5-18 Blank 5-19 - 5-23 5-24 Blank 5-25 - 5-27 5-28 Blank 6-1 - 6-7 6-8 Blank A-1 - A-4 B-1 - B-2

Dates of issue for original and changed pages are:

Original . . . . . . . . . . . . . . . . 0 . . . . .1 September 2003 Change . . . . . . . . . . . . . . . . 2 . . . . . . . . .10 June 2009 Change . . . . . . . . . . . . . . . . 4 . . . . . . 8 February 2012

Change. . . . . . . . . . . . . . . . . 1 . . . . . . 1 November 2006 Change. . . . . . . . . . . . . . . . . 3 . . . . . . . 25 January 2011

Page No.

*Change No.

Page No

*Change No.

Page No.

*Change No.

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

LIST OF EFFECTIVE PAGES

T.O. 31R4-2FRN45-2-33JG-1

i

TABLE OF CONTENTS

CHAPTER PAGE

Introduction ............................................................................................................................................................iii

1 Peculiar General Instructions (33-00-000)

1-1 Circuit Cards (33-00-001) .................................................................................................................1-1 1-1-1 Remove Circuit Cards (33-00-001-2) ...............................................................................................1-2 1-1-2 Install Circuit Cards (33-00-001-3) ...................................................................................................1-3

2 Power Supply 2A6 (33-26-000)

2-1 TACAN Power Supply Control 2A6A1 (33-26-100)..........................................................................2-1 2-1-1 Align TACAN Power Supply Control 2A6A1 (33-26-100-9) .............................................................2-2

3 Transponder 2A2 (33-35-000)

3-1 Transponder Assemblies (33-35-000)..............................................................................................3-1 3-1-1 Remove Transponder Assemblies (33-35-000-2) ............................................................................3-2 3-1-2 Install Transponder Assemblies (33-35-000-3) ................................................................................3-4 3-2 Control Indicator Interface 2A2A1 (33-35-100) and CODEC 6A1 (33-50-100)................................3-7 3-2-1 Align Control Indicator Interface 2A2A1 (33-35-100-9) and CODEC 6A1 (33-50-100-9) ................3-8 3-3 Video Processor 2A2A2 (33-35-110) .............................................................................................3-17 3-3-1 Align Video Processor 2A2A2 (33-35-110-9) .................................................................................3-18 3-4 Programmable Echo Level 2A2A3 (33-35-120) and Receiver 2A2A14 (33-35-230) .....................3-23 3-4-1 Align Programmable Echo Level 2A2A3 (33-35-120-9) and Receiver 2A2A14 (33-35-230-9)......3-24 3-5 Amplitude/Shape Controller 2A2A5 (33-35-140)............................................................................3-41 3-5-1 Align Amplitude/Shape Controller 2A2A5 (33-35-140-9) ...............................................................3-42 3-6 Encoder 2A2A8 (33-35-170)...........................................................................................................3-47 3-6-1 Align Encoder 2A2A8 (33-35-170-9) ..............................................................................................3-48 3-7 400 Watt Power Amplifier 2A2A10 (33-35-190) .............................................................................3-51 3-7-1 Align 400 Watt Power Amplifier 2A2A10 (33-35-190-9).................................................................3-52 3-8 Preselector 2A2A11 (33-35-200)....................................................................................................3-57 3-8-1 Align Preselector 2A2A11 (33-35-200-9) .......................................................................................3-58 3-9 Transmitter Receiver 2A2A14 (33-35-230) ....................................................................................3-73 3-10 Transmitter Frequency Synthesizer 2A2A15 (33-35-240)..............................................................3-75 3-10-1 Align Transmitter Frequency Synthesizer 2A2A15 (33-35-240-9) .................................................3-76 3-11 100 Watt Amplifier 2A2A16 (33-35-250) ........................................................................................3-79 3-11-1 Align 100 Watt Amplifier 2A2A16 (33-35-250-9) ............................................................................3-80 3-12 Directional Coupler 2A1A9 (33-37-180) .......................................................................................3-107 3-12-1 Remove Directional Coupler 2A1A9 (33-37-180-2)......................................................................3-108 3-12-2 Install Directional Coupler 2A1A9 (33-37-180-3)..........................................................................3-110 3-12-3 Measure/Calibrate Directional Coupler 2A1A9 (33-37-180-9) .....................................................3-112 ii

TABLE OF CONTENTS (Continued)

CHAPTER PAGE

4 Radio Frequency Monitor Assemblies (33-45-000)

4-1 Radio Frequency Monitor Assemblies (33-45-000)..........................................................................4-1 4-1-1 Remove Radio Frequency Monitor Assemblies (33-45-000-2) ........................................................4-2 4-1-2 Install Radio Frequency Monitor Assemblies (33-45-000-3) ............................................................4-4 4-2 Timing Pulse Generator 2A3/2A4A4 (33-45-130) ............................................................................4-5 4-2-1 Align Timing Pulse Generator 2A3/2A4A4 (33-45-130-9) ................................................................4-6 4-3 Monitor Multiplexer 2A3/2A4A6 (33-45-150) ....................................................................................4-9 4-3-1 Align Monitor Multiplexer 2A3/2A4A6 (33-45-150-9)......................................................................4-10 4-4 Time Base Interface 2A3/2A4A10 (33-45-190/33-46-190).............................................................4-15 4-4-1 Align Time Base Interface 2A3/2A4A10 (33-45-190-9/33-46-190-9) .............................................4-16 4-5 Voltage Regulator 2A3/2A4A11 (33-45-200)..................................................................................4-19 4-5-1 Align Voltage Regulator 2A3/2A4A11 (33-45-200-9) .....................................................................4-20 4-6 Frequency Synthesizer 2A3/2A4A13 (33-45-220)..........................................................................4-23 4-6-1 Align Frequency Synthesizer 2A3/2A4A13 (33-45-220-9) .............................................................4-24

5 Control Indicator Unit 6 (33-50-000)

5-1 Control Indicator Unit 6 (33-50-000).................................................................................................5-1 5-1-1 Operational Check Control Indicator Unit 6 (33-50-000-1)...............................................................5-2 5-1-2 Remove Control Indicator Unit 6 (33-50-000-2) ...............................................................................5-3 5-1-3 Install Control Indicator Unit 6 (33-50-000-3) ...................................................................................5-4 5-1-4 Inspect Control Indicator Unit 6 (33-50-000-6) .................................................................................5-5 5-2 Codec 6A1 (33-50-100) ....................................................................................................................5-7 5-3 Control Indicator Power Supply 6A2 (33-50-110).............................................................................5-9 5-3-1 Remove Control Indicator Power Supply 6A2 (33-50-110-2).........................................................5-10 5-3-2 Install Control Indicator Power Supply 6A2 (33-50-110-3).............................................................5-11 5-4 Control Indicator Power Supply Control 6A2A1 (33-50-112) .........................................................5-13 5-4-1 Align Control Indicator Power Supply Control 6A2A1 (33-50-112-9) .............................................5-14 5-5 Battery Assembly 6A3 (33-50-120) ................................................................................................5-19 5-5-1 Remove Battery Assembly 6A3 (33-50-120-2)...............................................................................5-20 5-5-2 Install Battery Assembly 6A3 (33-50-120-3)...................................................................................5-22 5-6 Power Monitor Display 6A4 (33-50-130) ........................................................................................5-25 5-6-1 Align Power Monitor Display 6A4 (33-50-130-9) ............................................................................5-26

6 Personal Computer Peripheral Connect Interface Cards (33-80-000)

6-1 Personal Computer Peripheral Connect Interface Cards (33-80-000) .............................................6-1 6-1-1 Remove Personal Computer Peripheral Connect Interface Cards (33-80-000-2) ...........................6-2 6-1-2 Install Personal Computer Peripheral Connect Interface Cards (33-80-000-3) ...............................6-5

Appendix A TACAN Reference Designator - S/S/SN Cross-Reference............................................................ A-1

Appendix B TACAN Navigational Set Replacement Index ................................................................................ B-1 iii

INTRODUCTION

1. PURPOSE.

This Job Guide (JG) manual provides organizational maintenance level instructions for the TACAN navigational set.

2. SCOPE.

This JG manual provides start-to-finish, step-by-step maintenance actions for the TACAN navigational set. The procedures in this JG are presented in a function/task arrangement with text supported by illustrations keyed to text procedural steps. Normally, text and illustrations will be on facing pages.

3. ILLUSTRATIONS.

Illustrations in the JG include a location view of the equipment on which the task is being performed and key numbers that are numerically identical to the task steps (figure 1). When a part/component within an illustration is referenced in more than one step in the procedure, the illustration will normally be keyed to each of the steps (figure 1, key numbers 4 and 5). When a step is referenced to another manual or to another function, that step will not be keyed on the illustration. Anytime a reference to another manual is made, the technician must go to that manual for the required information. The word TYPICAL when used on an illustration indicates that two or more configurations exist, but only one configuration is illustrated.

4. MULTI-SHEET ILLUSTRATIONS.

When multi-sheet illustrations are required, the task step number sequence will not be broken when proceeding from one sheet to the next.

5. PERSONNEL RECOMMENDED.

When personnel recommended exceeds one, each task step is coded with a letter(s) in parentheses after the step number to indicate the technician(s) recommended to accomplish the task step.

6. FUNCTION.

A function may consist of one or more tasks. Normally, all elements (input conditions, tasks, and follow-on maintenance) of a function must be accomplished to satisfy that function. In those cases where only one task or less than all of the tasks of a multi-task function are to be accomplished, the applicable input conditions and follow-on maintenance entries must be accomplished also. When a procedural step has an associated RESULT statement that cannot be obtained, the technician should refer to the fault index of the associated Fault Isolation manual.

7. NONSTANDARD ABBREVIATIONS.

The following nonstandard abbreviations are used in this job guide:

LRU - Line Replaceable Unit XMTR - Transmitter CB - Circuit Breaker JG - Job Guide SD - Schematic Diagram FI - Fault Isolation iv

Figure 1.

v

8. DEFINITION OF TERMS.

The following terms with definitions are used in this JG:

Function One or more tasks performed to assure that the system, or a component thereof, is in an operational ready state.

Task A set of steps describing a complete start-to-finish, step-by-step maintenance action.

Step A single maintenance action such as: Remove four nuts and four bolts.

9. CHANGE RECOMMENDATIONS.

Recommendations concerning changes to this JG shall be submitted IAW T.O. 00-5-1.

10. RECORD OF APPLICABLE TIME COMPLIANCE TECHNICAL ORDERS (TCTOs).

The following chart sets forth those TCTOs that are applicable to the equipment in this JG:

vi

RECORD OF APPLICABLE

TIME COMPLIANCE TECHNICAL ORDERS (TCTOs).

TCTO Number Title TCTO Date

31R4-2-509 Modification to Install Limited Transmitter Engineering Change Proposal (ECP-27), Power Conversion Engineering Change Proposal (ECP-3O), Power Jack Engineering Change Proposal (ECP-31), and On Request Mode Engineering Change Proposal (ECP-32) for AN/FRN-45 TACAN Navigational Set

1 Nov 90

31R4-2-510 Modification to Install 700 Watt Test Point Engineering Change Proposal (ECP-34) for AN/FRN-45 TACAN Navigational Set

1 Nov 90

31R4-2-511 Modification to Install Audio Engineering Change Proposal (ECP-22) and Power Monitor Display Assembly (Part of ECP-

25) for AN/FRN-45 TACAN Navigational Set

1 Nov 90

31R4-2FRN45-501 Modification to Install Burst/Ident Sync Generator Engineering Change Proposal (ECP-43) for AN/FRN-45 TACAN Navigational Set

1 Apr 97

31R4-2FRN45-502 Modification to Install Front Panel Test Points on the AN/FRN-45 TACAN Navigational Set

16 Apr 98

31R4-2FRN45-503 Modification to Install a Second +65 Volt Path for 700-Watt Amplifiers on the AN/FRN-45 TACAN Navigational Set

1 Feb 99

31R4-2FRN45-504 Modification to Install Upgraded EPROMS in the RF Monitors for the AN/FRN-45 TACAN

1 May 99

31R4-2-FRN45-505 Inspection of Frequency Synthesizer Modules in AN/FRN-45 TACAN Systems

1 Apr 02

31R4-2-FRN45-506 Inspection of TACAN Navigational Set AN/FRN-45 Power Supply, Part Number 105324

21 May 02

31R4-2FRN45-507 Modification to replace FCPU with Personal Computer 1 Sep 03 vii

11. SAFETY SUMMARY.

General Safety Notices:

Keep Away From Live Circuits. Always observe safety rules. Do not repair the equipment when the power is on unless necessary. Always turn off the power before touching any circuits. Before making adjustments, remove all jewelry. Make adjustments with one hand and keep the other away from the equipment.

Do Not Service or Adjust Alone. Do not enter an area to service or adjust the equipment at any time unless another person who can give aid is present.

Resuscitation. Anyone working with or near high voltages should know modern methods of resuscitation. These methods may be learned at the base hospital or at local medical facilities and in T.O. 31-1-141-1.

First Aid. Seek medical help immediately after injury. Any injury, however slight, should be treated.

GENERAL WARNINGS AND CAUTIONS

Ensure that all circuit breakers and power switches mounted on or connected to the transmitter group are OFF before checking wiring connections.

Use extreme care when working with the transponder group, transponder and radio frequency amplifier. Careless handling of metal tools can short out the 65 VDC, 25 ampere power source and result in death or serious injury. Before removing or installing any equipment in the rack, turn off all external power sources to the Transponder Group.

Lead soldering generates lead oxide fumes. Avoid breathing the fumes generated by soldering.

Eye protection is required. Do not flip solder off the soldering iron. The hot solder can cause severe burns.

Ensure that the transponder group antenna connector is connected to a matched antenna or high power termination prior to performing tests.

viii

Electrostatic Discharge Sensitive (ESDS) Devices are used in this assembly. Static electricity can damage these devices. Special handling methods and materials must be used to prevent damage. Do not touch or remove any ESDS device or any assembled circuit board that has an ESDS device without properly grounding your body, test equipment, and all tools. Be thoroughly familiar with the handling procedures specified in T.O. 00-25-234 and T.O. 31-1-141-1. Move or store assembled circuit boards only in conductive (antistatic) bags. Do not touch the printed circuits or the connector pins on the board; handle the board by the edges only. Keep the pins of an ESDS device shorted together whenever possible; use a device shorting bus, shorting tube, or conductive foam. ESD sensitive devices are identified in T.O. 31R4-2FRN45-2-33SD-1.

SPECIFIC WARNINGS AND CAUTIONS

The semi-rigid coax between the pre-selector and the rear of the transponder drawer can easily be damaged when unscrewing the SMA connector at the rear of the pre-selector. The backing off of this connector will cause binding at the bracket connection. It is required to loosen the bracket that secures the semi-rigid loop. (Page 3-58)

In the next step ensure 30-dB of attenuation is used for making a power measurement at 2A1J5.

(Page 3-102)

The battery backup for the control indicator is attached at Unit 6 TB2. Use care when disconnecting wires, otherwise personal injury may result. (Page 5-13)

Do not ground battery wire. Personal injury or equipment damage may result. (Page 5-14)

Keep open flames and spark producing sources away from storage batteries. Never lay metal tools on top of battery. Failure to heed these warnings may result in personal injury or equipment damage. (Page 5-19) ix/(x blank)

Use of a battery powered digital voltmeter is required while performing this procedure to prevent accidental damage to the equipment. (Page 2-2)

Damage can occur to Helix cable if bent excessive. It is recommended to take care when disconnecting this cable. (Page 3-24)

Avoid excessive bending of semi-rigid cables, otherwise they may be permanently damaged.

(Pages 3-2, 3-4, 4-2, and 4-4)

Electrostatic Discharge Sensitive (ESDS) devices are used in this assembly. Static electricity can damage these devices. Special handling methods and materials must be used to prevent damage. Do not touch or remove any ESDS device or assembled circuit board that has an ESDS device without properly grounding your body, test equipment, and all tools. Be thoroughly familiar with the handling procedures specified in T.O. 00-25-234 and T.O. 31-1-141-1. Move or store assembled circuit boards only in conductive (anti-static) bags. Do not touch the printed circuits or the connector pins on the board; handle the board by the edges only. Keep the pins of an ESDS device shorted together whenever possible; use a device shorting bus, a shorting tube, or conductive foam. (Page 6-2, 6-5)

33-00-001 1-1

CHAPTER 1.

PECULIAR GENERAL INSTRUCTIONS (33-00-000)

1-1 CIRCUIT CARDS (33-00-001)

INPUT CONDITIONS:

Applicability: All

Required Conditions: Appropriate assembly extended.

Personnel Recommended: Two

A: Technician

B: Safety Observer

Support Equipment: None

Supplies (Consumables): None

Safety Conditions: Remove power to assembly under repair prior to removal of subassemblies.

33-00-001-2 1-2

1-1-1 Remove Circuit Cards (33-00-001-2).

1. Set applicable circuit breaker and/or switches to OFF position.

2. Grasp ejector clip(s) on circuit card and lift up.

3. Pull circuit card from card guide in card bay.

Figure 1-1-1.

Change 1 1-3 33-00-001-3

1-1-2 Install Circuit Cards (33-00-001-3).

NOTE

Ensure circuit card is installed in correct card position.

1. Slide circuit card in card guide and push down into place until connector is seated.

2. Set applicable circuit breakers to ON position as stated in step 3.

3. To perform a complete system reset, turn OFF the TACAN assemblies and exit the FCPU program. Com-pletely rebooting is normally not required.

a. The RANTEC Modulation Generator should always be turned on first; without the NRB and ARB trig-gers the TACAN transmitter will not start.

b. Turn on A6 power supply AC, then DC breakers. Leave 65V Fan/Enable off for now.

c. Turn on A4 and then A3 monitor circuit breakers.

d. Turn on A2 transponder circuit breaker. If transponder is turn on before the monitors, check sum and malfunction erros (CKS/MAL) may occur.

e. Turn on the 65V Fan/Enable breaker.

f. Always insure the monitors are ON before executing the FCPU program. From the windows screen, execute the FCPU program and log in. The FCPU program should dispaly status for Monitor A and B.

g. From [Basic Control] menu,select [Acknowledge Alarm Indication], [Restore Transmitter to Service] and [Restore Power].

h. If monitor readings are not correct, reload facility references one at a time. Under [Comman Functions] select [System Adjustments] and enter site facility references and send.

NOTE

Do not use Monitor Facility Parmeters Refresh during a system reset because it may not load all the parameters.

4. Occasionally, one TACAN monitor may indacate that the command requested friom the FCPU did not take effect. Example: after sending cal mode 1 a window appears stating "TACAN Monitor B Failed to Respond ( CAL Mode 1)" or " Tried 3 times and no response from the TACAN Monitor B". when this occurs, use the following steps to rest the monitor:

a. Resend the command again;if monitor still does not carry out the command the next step is to reset the monitor

b. Turn OFF monitor and watch the PC screen Monitor or Maintenance data until CCCCCC are present;

this indicates that the FCPU program realizes the monitor is no longer on line.

NOTE

Do not turn monitor OFF and back ON quickly. The FCPU program will not see that the monitor was reset and may not try to re-initialize communication with the monitor.

1-4 Change 1 33-00-001-3

Figure 1-1-2.

c. Turn ON monitor and send the command;if the monitor fails to respond or MAL/CKS appears in the Status window a complete system reset in step may be required.

33-26-100 2-1

CHAPTER 2.

POWER SUPPLY 2A6 (33-26-000)

2-1 TACAN POWER SUPPLY CONTROL 2A6A1 (33-26-100)

INPUT CONDITIONS:

Applicability: All serial numbers

Required Conditions: Equipment removed from Operational Service.

Power Supply drawer extended.

Personnel Recommended: Two

A: Technician

B: Safety Observer

Support Equipment: Battery Powered Digital Multimeter

Safety Conditions: None

33-26-100-9 2-2

2-1-1 Align TACAN Power Supply Control 2A6A1 (33-26-100-9).

Use of a battery powered digital voltmeter is required while performing this procedure to prevent accidental damage to the equipment.

1. Set power supply FAN/65V ENABLE circuit breaker 2A6 CB2 to OFF position.

2. Remove small access cover from power supply.

3. Set 2A6A1 R36 (OUTPUT ADJ) fully CCW.

4. Set DMM to measure 350 mVDC.

5. Connect DMM negative lead to power supply control 2A6A1 TP10 (+65V)

6. Connect DMM positive lead to power supply control 2A6A1 TP9 (OVERCURRENT SENSE)

7. Adjust 2A6A1 R44 (OVERCURRENT ADJ) for +350 ±5 mVDC.

8. Set 2A6A1 R51 (OVERVOLTAGE ADJ) fully CW then 5 turns CCW.

9. Set DMM to measure 5.0 VDC and connect DMM positive lead to 2A6A1 TP7 (OVERVOLTAGE SENSE). (Leave the negative lead in TP10.)

10. Set power supply FAN/65V ENABLE circuit breaker 2A6 CB2 to ON position.

NOTE

If voltage remains at approximately 6 volts and R51 will not adjust, the 30-amp fuse, F1 is most likely defective.

11. Adjust 2A6A1 R51 (OVERVOLTAGE ADJ) for +5.0 VDC.

12. Set DMM to measure +65 VDC.

13. Connect DMM negative lead to 2A6A1 TP11 (+65V RETURN).

14. Connect DMM positive lead to 2A6A1 TP10 (+65V).

15. Adjust 2A6A1 R36 CW (OUTPUT ADJ) for +65.0 ±2.0 VDC.

16. From [Basic Control] menu, select [Acknowledge Alarm Indication], [Restore Transmitter to Service], and [Restore Power].

17. From [Maintenance Data] menu, select [Trans. Output Power].

18. Verify correct transponder output power.

19. Verify +65.0 ±2.0 VDC on DMM.

20. Disconnect DMM.

21. Reinstall small access cover on power supply.

22. Restore system to normal configuration.

33-26-100-9 2-3/(2-4 blank)

Figure 2-1-1.

33-35-000 3-1

CHAPTER 3.

TRANSPONDER 2A2 (33-35-000)

3-1 TRANSPONDER ASSEMBLIES (33-35-000)

INPUT CONDITIONS:

Applicability: All

Required Conditions: Transponder drawer extended.

Personnel Recommended: Two

A: Technician

B: Safety Observer

Support Equipment: None

33-35-000-2 3-2

3-1-1 Remove Transponder Assemblies (33-35-000-2).

NOTE

Removal of 400 watt power amplifier, pre- selector, power supply regulator, receiver, frequency synthesizer, and 100 watt amplifier is the same.

1. Set transponder POWER ON/OFF circuit breaker 2A2 CB1 to OFF position.

Avoid excessive bending of semi-rigid cables; otherwise they may be permanently damaged.

2. Disconnect connectors from appropriate assemblies.

3. Loosen captive screws.

4. Remove assembly from transponder unit.

33-35-000-2 3-3

Figure 3-1-1.

3-4 Change 1 33-35-000-3

3-1-2 Install Transponder Assemblies (33-35-000-3).

Avoid excessive bending of semi-rigid cables; otherwise they may be permanently damaged.

NOTE

Installation of 400 watt power amplifier, pre-selector, power supply regulator, receiver, frequency synthesizer, and 100 watt amplifier is the same.

1. Install appropriate assembly in transponder unit.

2. Secure with captive screws.

3. Connect all connectors to appropriate assembly.

4. Set transponder POWER ON/OFF circuit breaker CB1 to ON position.

5. If monitor Aor B fails to communicate after transponder is turned on follow steps in para 1-1-2 step 3 for system reset.

33-35-000-3 3-5/(3-6 blank)

Figure 3-1-2.

33-35-100 3-7

3-2 CONTROL INDICATOR INTERFACE 2A2A1 (33-35-100) AND CODEC 6A1 (33-50-100)

INPUT CONDITIONS:

Applicability: All serial numbers

Required Conditions: Equipment removed from operational service.

Control indicator removed from rack.

Control indicator top access cover removed.

No opens or shorts exist in phone lines.

Personnel Recommended: Four

A: Technician at TACAN site.

B: Technician at remote monitoring facility.

C: Safety observer at TACAN site.

D: Safety observer at remote monitoring facility.

Support Equipment: Oscilloscope (2 required) X10 probe with ground clip (2 required)

Supplies (Consumables): None

Safety Conditions: Use caution when removing the control indicator Unit 6, 32-50-000. AC power, signal lines and battery power wiring are connected to rear terminal board.

3-8 Change 1 33-35-100-9

3-2-1 Align Control Indicator Interface 2A2A1 (33-35-100-9) and CODEC 6A1 (33-50-100-9).

1. (A: Technician) Set monitor A and B timebase interface switch 2A3/A4A10 S1 to BYPASS position.

2. (A: Technician) From [Basic Control] menu, select [Remove Identification].

3. (A: Technician) Set control indicator interface switch 2A2A1 S1 to REMOTE position.

4. (A: Technician) Adjust control indicator interface 2A2A1 R1 (DETECTED AUDIO ATTENUATOR ADJ) fully

CCW.

5. (A: Technicain) Set oscilloscope channel 1 Volts/Div to 0.5VAC and Time /Div to 5.0 ms.

6. (A: Technician) Connect oscilloscope probe ground lead to control indicator interface 2A2A1 TP6 (GND).

7. (A: Technician) Connect oscilloscope channel 1 to control indicator interface 2A2A1 TP5 (TELEPHONE

LINE OUTPUT).

8. (A: Technician) Adjust control indicator interface 2A2A1 R16 (AUDIO LEVEL ADJ) for a 2.8 ±0.2 volt peak-to-peak signal level.

33-35-100-9 3-9

Figure 3-2-1 (Sheet 1 of 4).

3-10 Change 1 33-35-100-9

9. (B: Technician) Set control indicator Unit 6 POWER ON/OFF circuit breaker CB1 to OFF position.

10. (A: Technician) Connect oscilloscope channel 1 to control indicator interface 2A2A1 TP4 (RECEIVE

LEVEL).

11. (A: Technician) Adjust control indicator interface 2A2A1 R72 (CANC ADJ) for a minimum signal level.

12. (B: Technician) Set control indicator Unit 6 POWER ON/OFF circuit breaker CB1 to ON position.

13. (A: Technician) Set transponder POWER ON/OFF circuit breaker 2A2 CB1 to OFF position.

14. (B: Technician) Connect oscilloscope probe ground lead to CODEC 6A1 TP15 (GND).

15. (B: Technician) Connect oscilloscope channel 1 to CODEC 6A1 TP13 (TACAN TELEPHONE INPUT).

16. (B: Technicain) Set oscilloscope channel 1 Volts/Div to 0.5VAC and Time /Div to 5.0 ms.

17. (B: Technician) Adjust CODEC 6A1 R112 (BALANCE ADJ) for a minimum signal level.

18. (A: Technician) Set transponder POWER ON/OFF circuit breaker 2A2 CB1 to ON position.

19. (B: Technicain) Set oscilloscope channel 1 Volts/Div to 0.5VAC and Time /Div to 5.0 ms.

NOTE

In the next step, the technician should adjust for a peak-to-peak voltage that is compatible with the quality of the telephone line.

20. (A: Technician) Adjust control indicator interface 2A2A1 R16 (AUDIO LEVEL ADJ) CCW until communica-tion is lost between control indicator interface 2A2A1 and CODEC 6A1 (status lamps on the control indica-tor are erratic or extinguished).

(B: Technician) Observe the peak-to-peak voltage when communication is lost and instruct (A: Technician) to adjust 2A2A1 R16 CW until the peak-to-peak voltage at 6A1 TP13 is a nominal 3.0 VAC above the level observed when communication was lost.

3-11

Figure 3-2-1 (Sheet 2).

3-12 Change 1 33-35-100-9

21. (A: Technician) Set transponder burst/ident/sync generator switch 2A2A7 S1 to FTK position.

22. (A: Technician) Connect oscilloscope channel 1 to control indicator interface 2A2A1 TP2 (FM MODULA-

TOR BANDPASS OUTPUT).

23. (A: Technician) Adjust oscilloscope channel 1 vertical VOLT/DIV variable and position controls for a 6 cm peak-to-peak reference.

24. (A: Technician) Without changing oscilloscope controls, move oscilloscope channel 1 to control indicator interface 2A2A1 TP3 (ATTENUATED DETECTED AUDIO).

25. (A: Technician) Adjust control indicator interface 2A2A1 R1 (DETECTED AUDIO ATTENUATOR ADJ) CW for a 3 cm peak-to-peak signal level.

26. (A: Technician) Set transponder burst/ident/sync generator switch 2A2A7 S1 to NOR position.

27. (B: Technicain) Set oscilloscope Time /Div to 2.0 ms.

28. (B: Technician) Connect oscilloscope channel 1 to CODEC 6A1 TP9 (TACAN FM MODULATION).

29. (B: Technician) Set oscilloscope channel 1 vertical input to GND and adjust vertical position control to place the trace on the center graticule.

30. (B: Technician) Set oscilloscope channel 1 vertical input to DC.

31. (B: Technician) Adjust CODEC 6A1 R94 (FM AMP ADJ) so the peak of the sine wave negative alternation is -11.0 ±0.5 VDC.

32. (B: Technician) Set oscilloscope channel 1 VOLT/DIV to 0.5 VAC.

33. (B: Technician) Connect oscilloscope channel 1 to CODEC 6A1 TP10 (TACAN OUTPUT).

34. (B: Technician) Adjust CODEC 6A1 R101 (PWR ADJ) for a 2.8 ±0.2 volt peak-to-peak signal level.

35. (A: Technician) Set oscilloscope channel 1 VOLT/DIV to 0.5 VAC.

3-13

Figure 3-2-1 (Sheet 3).

3-14

36. (A: Technician) Connect oscilloscope channel 1 to control indicator interface 2A2A1 TP4

(RECEIVE LEVEL).

NOTE

In the next step, the technician should adjust for a peak-to-peak voltage that is compatible with the quality of the telephone line.

37. (B: Technician) Adjust CODEC 6A1 R101 (PWR ADJ) CCW until modulation at 2A2A1 TP4 is lost.

(A: Technician) Observe the peak-to-peak voltage when modulation is lost and instruct (B:

Technician) to adjust 6A1 R101 CW until the peak-to-peak voltage at 2A2A1 TP4 is 3 VAC above the level observed when modulation was lost.

38. (B: Technician) Adjust CODEC 6A1 R119 (AMP VOL) fully CW.

39. (B: Technician) Cycle control indicator Unit 6 POWER ON/OFF circuit breaker CB1 to OFF, then to

ON.

40. (B: Technician) Adjust CODEC 6A1 R119 (AMP VOL) CCW for a desired audible alarm level.

41. (B: Technician) Depress control indicator Unit 6 ALARM SILENCE push-button S5 to silence audible alarm.

42. (B: Technician) Disconnect oscilloscope from CODEC 6A1.

43. Perform transmitter/control indicator check (T.O. 31R4-2FRN45-2-33GE-1 paragraph 5.2.2.18).

44. (B: Technician) Install access cover on control indicator Unit 6.

45. (B: Technician) Install control indicator Unit 6.

46. Restore equipment to normal operating configuration.

3-15/(3-16 blank)

Figure 3-2-1 (Sheet 4).

33-35-110 3-17

3-3 VIDEO PROCESSOR 2A2A2 (33-35-110)

INPUT CONDITIONS:

Applicability: All serial numbers

Required Conditions: Equipment removed from operational service.

Transponder drawer extended.

Align Monitor B Frequency Synthesizer (33-45-220-9).

Calibrate oscilloscope test probes.

Personnel Recommended: Two

A: Technician

B: Safety Observer

Support Equipment: Oscilloscope X10 probe with ground clip (2 required) 6 foot, 50 ohm RG-223 Test Cable

33-35-110-9 3-18

3-3-1 Align Video Processor 2A2A2 (33-35-110-9).

1. From [Basic Control] menu, select [Remove Transmitter From Service].

2. Set power supply FAN/65V ENABLE circuit breaker 2A6 CB2 to OFF position.

3. Set monitor A POWER ON/OFF circuit breaker 2A3 CB1 to OFF position.

NOTE

Monitor communication errors will be experienced during this alignment. Data entries will still be accepted by the energized monitor.

4. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 1 and [Send].

NOTE

Ensure oscilloscope probes are properly grounded. Use Monitor B for oscilloscope sync signals.

5. Connect oscilloscope external trigger to Monitor B 2A4J6 (TRIG OUT EN).

6. Set oscilloscope TIME/DIV control to 2 µsec.

7. Connect oscilloscope channel 1 to 2A2A2 TP8 (.55 µs DELAYED VIDEO) and adjust oscilloscope controls for full scale deflection of the signal.

8. Move the oscilloscope channel 1 test probe to 2A2A2 TP7 (2.82 µs DELAYED VIDEO). Do not adjust vertical gain or position controls.

9. Adjust 2A2A2 R26 (GAIN ADJ) for full scale deflection of the signal without distortion.

10. Remove oscilloscope probe from 2A2A2 TP7.

11. Connect oscilloscope channel 1 to 2A2A2 TP10 (BUFFERED 2.82 µs DELAYED VIDEO).

3-19

Figure 3-3-1 (Sheet 1 of 2).

3-20

12. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 60 and select [Send].

13. Adjust oscilloscope VOLTS/DIV variable control for calibrated setting.

14. Adjust oscilloscope VOLTS/DIV control for maximum on-scale deflection.

15. Adjust channel 1 vertical position control until the trace baseline is at the bottom graticule.

NOTE

Ensure test probes are calibrated for amplitude response.

16. Record the peak pulse amplitude at TP10.

17. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 54 and select [Send].

18. Connect oscilloscope channel 2 to 2A2A2 TP11 (SUMMED VIDEO OUTPUT).

19. Adjust oscilloscope channel 2 VOLTS/DIV to the same settings as channel 1.

20. Adjust oscilloscope channel 2 vertical position control until the trace baseline is at the bottom graticule.

21. Adjust R19 until the peak of the signal on channel 2 (TP11) equals the voltage level recorded at

TP10.

22. Disconnect Test Equipment.

23. Set monitor A POWER ON/OFF circuit breaker 2A3 CB1 to ON position.

24. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 0 and [Send].

25. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 91 and select [Send].

26. Set FAN/65V ENABLE circuit breaker 2A6 CB2 to ON position.

27. From [Basic Control] menu, select [Acknowledge Alarm Indication], [Restore Transmitter to Service], and [Restore Power].

28. From [Monitored Data] menu, select [Monitored Data Control] and [Repeat Monitored Data].

29. Verify Monitor Data parameters are within fault limits.

30. Restore system to normal operating configuration.

3-21/(3-22 blank)

Figure 3-3-1 (Sheet 2).

Change 1 3-23 33-35-230

3-4 PROGRAMMABLE ECHO LEVEL 2A2A3 (33-35-120) AND RECEIVER 2A2A14 (33-35-230).

INPUT CONDITIONS:

Applicability: All serial numbers.

NOTE

The Programmable Echo Level (33-35-120) and the Receiver (33-35-230) alignments have been combined into one alignment.

Required Conditions: Equipment removed from operational service.

Transponder drawer extended.

Ensure transponder burst/ident/sync generator switch 2A2A7 S1 is in NOR position.

Align Monitor A and B Frequency Synthesizer (33-45-220-9).

Monitor A or B Extended.

Ensure Monitor Bypass/Normal Switch is in the NORMAL position

Personnel Recommended: Two A: Technician B: Safety Observer

Support Equipment: Oscilloscope X10 probe with ground clip (2 required) and ensure probes are user calibrated 6 foot 50 ohm RG-223 Test Cable Tuning tool, PN 7104-9 Tuning tool (small blade type for adjusting capacitors)

3-24 33-35-230-9

3-4-1 Align Programmable Echo Level 2A2A3 (33-35-120-9) and Receiver 2A2A14 (33-35-230-9).

1. Set transponder POWER ON/OFF circuit breaker 2A2 CB1 to OFF position.

2. Set power supply 65V/FAN ENABLE circuit breaker 2A6 CB2 to OFF position.

Damage can occur to Helix cable if bent excessive. It is recommended to take care when disconnecting this cable.

3. Disconnect antenna cable from connector J5 at rear of transponder cabinet Unit 2.

4. Remove programmable echo level 2A2A3 card from transponder. (Refer to JG 33-00-001-2.)

5. Install 48 pin extender card in programmable echo level slot.

NOTE

In the next step ensure the extender card is not shorted to the connector on top of the 2A2A4 circuit card.

6. Place programmable echo level 2A2A3 card on extender card.

NOTE

All Adjustable resistors are 20 turn potentiometers. If you do not hear the end adjustment clicking, then adjust for minimum of 20 turns.

7. Adjust programmable echo level 2A2A3 R57 (CW JAMMING THRESHOLD ADJ) fully CCW.

8. Adjust programmable echo level 2A2A3 R79 (AGC THRESHOLD ADJ) fully CCW.

9. Adjust programmable echo level 2A2A3 R67 (INITIAL AGC) fully CW.

10. Adjust receiver frequency discriminator 2A2A14A3 R24 (FREQUENCY DISCRIMINATOR GAIN ADJ) fully

CCW

11. Adjust receiver frequency discriminator 2A2A14A3 R46 (NOISE THRESHOLD ADJ) fully CW.

12. Set transponder POWER ON/OFF circuit breaker 2A2 CB1 to ON position.

13. Set monitor not being used POWER ON/OFF circuit bearker 2A3/A4 CB1 to OFF.

NOTE

Monitor communication errors will be experienced during this alignment. The energized Monitor will still accept data entries.

33-35-230-9 3-25

Figure 3-4-1 (Sheet 1 of 8).

3-26 Change 1 33-35-230-9

NOTE

Steps 14 through 21 cover adjustment of the Receiver's Two-Pole Filter. The On-Channel interrogations viewed at TP12 are from the monitor interrogator and are similar to actual aircraft interrogations

14. [System Adjustments] menu, select TACAN [Calibration/Test Mode], 1 and [Send].

NOTE

The oscilloscope probes should be properly grounded throughout this procedure to ensure clear displays.

15. Connect oscilloscope channel 1 to video processor 2A2A2 TP12 (RECEIVER VIDEO).

16. Set oscilloscope CH 1 VOLTS/DIV control to 1.0 V and TIME/DIV to 2.0 µs.

NOTE

The Monitor TRIGGER OUT ENABLE from the Interrogation Trigger Generator has been routed to the front of each monitor.

17. Connect 50-ohm test cable between Monitor B 2A4J6 and oscilloscope Channel 4.

18. Trigger oscilloscope externally on Channel 4 and positive slope on Monitor J6(TRIGGER OUT ).

3-27

Figure 3-4-1 (Sheet 2).

3-28 Change 1 33-35-230

19. Adjust receiver 2A2A14A5 C6 and C7 (TWO-POLE FILTER ADJ) for maximum pulse amplitude.

NOTE

The amplitude of the pulses viewed at TP12 in Calibration Mode 1 (Interrogation Level -30) should be approximately 6 volts peak. If they are significantly lower the Receiver could be defective.

20. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 80 and select [Send].

21. Set oscilloscope VOLTS/DIV control to 0.5V.

22. Adjust receiver 2A2A14A5 C6 and C7 (TWO-POLE FILTER ADJ) for maximum pulse amplitude.

NOTE

• The amplitude of the pulses at TP12, with an interrogation level of 80, should be approximately 2 volts peak.

• The following steps cover the Noise Threshold adjustment.

23. Set oscilloscope VOLTS/DIV to 0.1V and TIME/DIV to 2.0 ms.

NOTE

During noise measurements ensure the probe is grounded on the Receiver chassis ONLY and not to a ground test point.

24. Connect oscilloscope channel 1 to receiver 2A2A14A3 TP8 (ON-CHANNEL VIDEO).

25. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 110 and select [Send].

26. Adjust receiver (A14) C58 (LIMITED RF OUTPUT LEVEL ADJ) until an average video noise level of 200 mV peak-to-peak is obtained.

27. Adjust receiver frequency discriminator (A14) R24 CW (FREQUENCY DISCRIMINATOR GAIN ADJ) for an average video noise level of approximately 150 mV peak-to-peak.

NOTE

In the following step the oscilloscope is set to measure 1 second every two divisions.

28. Set oscilloscope VOLTS/DIV control to 1.0V and TIME/DIV to 5 seconds.

3-29

Figure 3-4-1 (Sheet 3).

3-30

29. Connect oscilloscope channel 1 to encoder 2A2A8 TP12 (DEAD TIME GATE).

30. From [Maintenance Data] menu, select [Maintenance Data Control] and [Repeat Maintenance Data].

NOTE

In the next step a minimum number of pulses can be observed by two different methods. You can observe the oscilloscope for one pulse per second, (one every two divisions) or you can view the PC screen for a count of 0 to 5. It may be necessary to move the Maintenance Data window such that the Dead Time Gate Data is visible while adjusting the Efficiency Interrogation Level.

31. Adjust receiver frequency discriminator (A14) R46 CCW until a minimum number of pulses are observed on the PC screen (0-5 count).

32. Using the [System Adjustments] menu selection [Set Efficiency Inter Level], increase interrogation level in 1 dBm steps from -110 dBm (i.e.: -110 dBm to -109 dBm) until the Dead Time Gate Data on the Maintenance Data window indicates an average count of 700 ±50.

33. Increase interrogation level by an additional 0.5 dBm (i.e.: -95 dBm to -94.5 dBm).

34. Readjust receiver frequency discriminator (A14) R46 CCW until an average count of 700 ±50 is obtained.

NOTE

The following steps cover adjustment for CW Detection.

35. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 6 and [Send] (CW on-channel interrogation at Efficiency Interrogation Level).

36. From [System Adjustments] menu, select [Set Efficiency Inter Level], enter 110 and select [Send].

37. Set oscilloscope VOLTS/DIV to 0.1V and TIME/DIV to 2.0 ms.

38. Connect oscilloscope channel 1 to programmable echo level 2A2A3 TP7 (FILTERED ON-CHANNEL

VIDEO).

39. Adjust vertical position control to put trace on center graticule (or as close as possible).

NOTE

• If the trace is at the top of the screen and will not come down, enter the Efficiency Interrogation Level of -110 again.

• If the required DC level tolerance in the next step cannot be obtained with 1.0 dBm, steps, use 0.5 dBm steps.

40. Increase efficiency interrogation level in 1.0 dBm steps until the average DC level rises +0.1 ±0.05

VDC.

41. Set oscilloscope VOLTS/DIV to 0.2 and TIME/DIV to 5.0 ms.

42. Connect oscilloscope channel 1 to programmable echo level 2A2A3 TP8 (CW JAMMING

THRESHOLD).

3-31

Figure 3-4-1 (Sheet 4).

3-32 Change 1 33-35-230-9

43. Adjust oscilloscope vertical position control to put trace on the bottom graticule.

44. Adjust programmable echo level (A3) R57 CW until the DC level just becomes active (just rises).

45. Adjust programmable echo level (A3) R57 1/2 turn CCW.

NOTE

The following steps cover adjustment of Interrogation Overload.

46. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 5 and [Send].

47. Set oscilloscope channel 1 VOLTS/DIV to 1.0 VDC.

48. Connect oscilloscope channel 1 to programmable echo level (A3) TP12 (INTERROGATION OVERLOAD

THRESHOLD).

NOTE

A HIGH is approximately 2-3 VDC and a LOW is approximately .8 VDC. If the DC level only increases to 1-1.5 VDC,then correct presetting of R67 (Fully CW). Ignore 7 seconds lows during ID.

49. Adjust programmable Echo Level (A3) R79 (AGC THRESHOLD ADJ) CW until the LOW DC level floats to a predominate HIGH.

50. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 4 and [Send].

51. Observe that the DC level floats to a predominate LOW. (A slight adjustment of R79 may be required to attain a stable level).

52. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 5 and [Send].

53. Observe that the DC level floats to a stable HIGH.

54. If previous steps do not meet the required conditions, adjust Programmable Echo Level (A3) R79 slightly, and repeat until required conditions are met.

NOTE

• The following steps cover adjustment of Initial Receiver Sensitivity.

• Removal of W1 in the next step disables the tracking A/D circuit so the PEL card thinks the TACAN Transponder has just been turned on.

• Use an Alligator Clip to remove and reinstall W1.

55. Remove jumper W1 from Programmable Echo Level connectors 2A2A3 J1 and J2.

56. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 2 and [Send].

57. Set oscilloscope channel 1 and 2 VOLTS/DIV to 0.5V and TIME/DIV to 2.0 µs.

3-33

Figure 3-4-1 (Sheet 5).

3-34 Change 1 33-35-230-9

58. Connect oscilloscope channel 1 to video processor (A2) TP12 (RECEIVER VIDEO).

59. Connect oscilloscope channel 2 to programmable echo level (A3) TP2 (RECEIVER SENSITIVITY LOOP

REFERENCE VOLTAGE).

60. Set channel 1 and 2 vertical position controls for a DC ground level on the bottom graticule.

61. Activate oscilloscope Channel 1 and 2, Input DC.

62. Adjust programmable echo level (A3) R8 (COARSE SENSITIVITY ADJ) until the DC level on channel 2 is equal to the peak of the pulse on channel 1.

63. Install jumper W1 between programmable echo level connectors 2A2A3 J1 and J2.

NOTE

The following steps cover Calibration of Echo Trigger Level.

64. Set oscilloscope channel 1 and 2, VOLTS/DIV control to 1V

65. Connect oscilloscope channel 2 to programmable echo level (A3) TP1 (ECHO SUPPRESSION TRIGGER LEVEL REFERENCE). (Leave channel 1 connected to video processor (A2) TP12)

66. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 3 and [Send].

67. Ensure operating Monitor Timebase Interface Switch A10 S1 is in the NOR position.

68. Set channel 1 and 2 vertical position controls for a DC ground level on the bottom graticule.

NOTE

• It may be necessary to dim the room lights in order to view this pulse. Adjustments of R13 and R27 in the following steps interact.

• In the following steps, the pulse amplitude and DC level are lower in the BYPASS mode.

• If the DC level on channel 2 will not equal the peak of the pulse on channel 1, center R13 and R27.

69. Adjust programmable echo level (A3) R13 (ECHO TRIGGER LEVEL ADJ) until the DC level on channel 2 is equal to the peak of the pulse on channel 1.

70. Set operating monitor Timebase Interface Switch A10 S1 to BYPASS position.

71. Adjust programmable echo level (A3) R27 (ECHO TRIGGER LEVEL BIAS ADJ) until the DC level on channel 2 is equal to the peak of the pulse on channel 1.

72. Repeat previous step until the DC level at Programmable Echo Level (A3) tracks the peak of the pulse at Video Processor (A2) TP12 for both setting of Monitor Timebase Inteface Switch A10 S1.

3-35

Figure 3-4-1 (Sheet 6).

3-36 Change 1

33-35-230-9

NOTE

The following steps cover adjustment of Initial AGC (Receiver Gain).

73. Disconnect oscilloscope channel 2 from (A3) TP1 (Leave channel 1 connected).

74. Verify oscilloscope channel 1 TIME/DIV control to 2.0 µs.

75. Set monitor being used Timebase Interface Switch A10 S1 to NOR position.

76. From [System Adjustments] menu, select TACAN [Calibration/Test Mode], 1 and [Send].

77. Adjust programmable echo level (A3) R67 (INITIAL AGC ADJ) CCW until the peak of the pulse on channel 1 just begins to drop.

78.Adjust programmable echo level (A3) R67 1/4 turn CW.

NOTE

• The following steps cover adjustment of Echo Desensitization.

• When W2 is removed it will disable the Monitor INTERROGATION BRACKET. Without the Monitor INTERROGATION BRACKET the PEL Card thinks Monitor Interrogations are aircraft interroga-tions and the Echo Suppression circuits can be aligned using monitor interrogations.

79. Remove jumper W2 from programmable echo level connectors (A3) J3 and J4.

80. Set channel 1 TIME/DIV to 10 µsec and vertical position control for a DC ground level on the bottom grati-cule.

81.