TM 11-6625-820-45 · AMP TEST pushbutton switch S4 is pressed, it connects 27.5 volts dc to the RMI servoam-plifier and to flag meter relay K2. The flag meter relay energizes and

TM 11-6625-820-45D E P A R T M E N T O F T H E A R M Y T E C H N I C A L M A N U A L

GS AND DEPOT MAINTENANCE MANUAL

TEST SET, RADIO AN/ARM-92

H E A D Q U A R T E R S , D E P A R T M E N T O F T H E A R M Y

SEPTEMBER 1966

WARNING

Be careful when working on the 115-volt, 400-cps circuit. Seriousinjury or death may result from contact with this circuit.

DON’T TAKE CHANCES!

CAUTION

Do not make resistance measurements with power applied to the testset. Do not make resistance measurements that would place the ohmeteracross a microampere meter in the test set.

TM 11-6625-820-45C 2

C H A N G E

No. 2

H E A D Q U A R T E R SDEPARTMENT OF THE ARMY

W A S H I N G T O N , D. C., 21 January 1972

General Support and Depot Maintenance Manual

Including Repair Parts and Special Tool Lists

TEST SETS, RADIO AN/ARM-92 AND AN/ARM-92A

TM 11–6625–820–45, 22 September 1966, is changed as follows:

1. Remove and insert pages as indicated below.

Insert pages Remove pagesi and ii _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ i and ii1-1 and 1-2_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1-1 and 1-2_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1-2.1 and 1-2.2

1-3and 1-4_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1-3 and 1-4_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1-4.1 /(1.4.2 blank)1-5 through 1-8 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _1-5 through 1–82-1 through 2–4 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2-1 through 2-4_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2-4.1 and 2-4-22-5 and 2-6 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2-5 and 2-6_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2–6.1 and 2-6.22-11 and 2-12 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2–11 and 2-122-17 through 2-20 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2-17 through 2-223-1 through 3-6_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3-1 through 3–84-1 and 4-2 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4-1 and 4-2_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4-2.1 (4-2.2 blank)4-3 and 4-4 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4-3 and 4-44-7 and 4-8_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _4-7 and 4-84-11 through 4-14_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4-11 through 4-144-15 through 4-24 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _4-15 through 4–24_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _4–24.1/(4.24.2 blank)_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Figure 4-9.1 (Sheet 1 of 2)_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Figure 4–9.1 (Sheet 2 of 2)Appendix A-1 and A-2_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Appendix A-1 and A-2Index I-1 and I-2_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Index I-1 and I–2

2. File this change sheet in front of the manual for future reference.

TM 11-6625-820-45*C 1

C H A N G E H E A D Q U A R T E R SDEPARTMENT OF THE ARMY

No. 1 W A S H I N G T O N, D.

G5 and Depot Maintenance Manual

Including Repair Parts and Special Tools List

TEST SET, RADIO AN/ARM-92

TM 11-6625-820-45, 22 September 1966, is changed as follows:

1. The title of the manual is changed as shown above.

2. Remove old pages and insert new pages as indicated below.

Remove pages Insert pages

1-1 and 1-2 1-1 and 1-2A - 1 A - 1

B-1 through

C., 3 December 1968

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

By Order of the Secretary of the Army:

Official:

W. C. WESTMORELAND,General, United States Army,Chief of Staff.

KENNETH G. WICKHAM,Major General, United States Army,The Adjutant General.

Distribution:

To be distributed in accordance with DA Form 12-36 (Unclassified) requirements for Direct and GeneralSupport Maintenance Literature for the OV-1A, OV-1B, OV-1C, U-8F, U-10A, CH-47A, UH-1B, UH-1D

and OH-6A Aircrafts.

U.S. GOVERNMENT PRINTING OFFICE: 1968-344430/605

* This change supersedes TM 11-6625-820-25P, 7 April 1966.

B - 3 8

TECHNICAL M A N U A L

No. 11–6625–820-45

TM 11-6625-820-45

HEADQUARTERS,DEPARTMENT OF THE ARMY

W A S H I N G T O N , D.C., 22 September 1966.

GS AND DEPOT MAINTENANCE MANUAL

CHAPTER I.S ECTION I .

II.CHAPTER 2.S ECTION I .

II.CHAPTER 3.S ECTION I .

II.CHAPTER 4.

APPENDIX.

TEST SETS, RADIO AN/ARM-92 AND AN/ARM-92A

P a r a g r a p h P a g e

FUNCTIONINGGeneral functioning of Test Sets, Radio AN/ARM-92 and AN/ARM-92A_ 1-1, 1-2 1-1,1-1Detailed circuit functioning _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ 1–3—1-8 1-3--1-6TROUBLESHOOTINGGeneral troubleshooting techniques _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2-1--2-3 2-1--2-2Troubleshooting procedures _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2-4--2-9 2-2--2-21REPAIR AND ALIGNMENTRepairs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3-1—3-6 3-1—3-5Alignment _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3-7--3-12 3-5--3-8GENERAL SUPPORT TESTING PROCEDURES AND 4-1--4-16 4-1-–4-22

DEPOT OVERHAUL STANDARDS _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ A-1REFERENCES _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

INDEX _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ I-1

*This manual supersedes TM 11-6625-820-45, 15 February 1966.

Change 2 i

TM 11-6625-820-45

CHAPTER 1

FUNCTIONING

Section I. GENERAL FUNCTIONING OF TEST SETS,RADIO AN/ARM-92 AND AN/ARM-92A

1-1. Scope

a. General. This manual contains generalsupport and depot maintenance instructionsfor Test Sets, Radio AN/ARM-92 and AN/ARM-92A. It includes instructions appro-priate to these categories of maintenancefor troubleshooting, testing, aligning, andrepairing the equipment. The manual alsolists tools, materials, and test equipmentfor maintenance. Detailed functions of theequipment are also covered.

b. Reporting of Equipment Manual Improve-ments. The direct reporting of errors, omis-sions, and recommendations for improving thisequipment manual by the individual user is au-thorized and encouraged. DA Form 2028 (Rec-ommended Changes to DA Publications) willbe used for reporting these improvements. Thisform may be completed using pencil, pen, ortypewriter and forwarded direct to Command-ing General, U. S. Army Electronics Com-mand, ATTN: AMSEL-MR-NMP-AD, FortMonmouth, N, J. 07703.

Note: For other applicable forms and records, seeparagraph 1-3, TM 11-6625-820-12.

c. Index of Equipment Publication. Refe rto the latest issue of DA Pam 310-4 to deter-mine whether there are new editions, chang-es or additional publications pertaining to theequipment. DA Pam 310-4 is a current indexof technical bulletins, supply bulletins, lubri-cation orders, and modification work ordersavailable through publications channels. Theindex lists the individual parts (-10, -20, -35P,etc) and the latest changes and revisions ofeach equipment publications.

1-2. Block Diagram Functioning ofTest Set, Radio AN/ARM-92

a. General. Test Set Radio, AN/ARM-92provides for the complete testing of RadioReceiving Set AN/ARN-82 (receiving set) whenused with external test equipment. The testset can also be used to test a glide-slope re-ceiver, and provides for flag and deviationloading. The glide-slope test requires aspecial cable that is not supplied with thisunit. The functions of Test Set, Radio AN/ARM-92 are:

(1) Power distribution.(2) Phase shifting.(3) Current measuring.(4) Compass simulation.(5) Self-test of control unit and func-

tions of the test set.b. Power Distribution Circuits. Control, Ra-

dio Set C–6873/ARM-82 (control unit), powerrelay K1, and power transformer T1 comprisethe power distribution circuits. The test set con-nects 27.5 volts direct current (dc) from anexternal power source to the control unit whichapplies or removes the 27.5 volts dc from theremaining power circuits. When the controlunit applies this voltage to the remaining pow-er circuits, 27.5 volts dc is applied to RadioReceiver R–1388/ARN-82 (radio receiver), orto the glide-slope receiver, and to power relayK1. The relay then energizes and connects 115volts, 400 cycles per second (cps) to powertransformer T1. Transformer T1 steps the volt-age down to 26 volts, 400 cps, which is ap-plied to the radio receiver. The control unit alsosupplies the tuning information required by theradio receiver, or the glide-slope receiver.

Change 2 1-1

TM 11-6625-820-45

c. Phase Shifting

Figure 1-1. Test Set, Radio

Circuits. The phase shift-ing circuits (comprised of precision bearingtransformer T2; Indicator, Course ID-1347/ARN–82, OBS (omni bearing switch) indica-tor; BEARING switch S3; and BRG-OBSswitch S2) are used to shift the phase of the

1-2

AN/ARM-92, block diagram.

30-cycle refererence signal obtained from theradio receiver. Either the OBS resolver or pre-cision bearing transformer T2 performs thephase shifting, and BRG–OBS switch S2 se-lects the one to be used. The OBS resolvershifts the phase of the 30-cycle reference signal

TM 11-6625-820-45

anywhere from 0 to 360°, but precision bear-ing transformer T2 shifts the phase of the sig-nal in precise 30° increments. The exact 30° in-crement is selected by BEARING switch S3.

d. Current Measuring Circuits. T O - F R O Mmeter M3 connects directly to the radio receiverand measures its to-from current. DEVIATIONmeter M1 and FLAG meter M2 are connectedeither to the radio receiver or to the glide-slopereceiver, depending on the position of VOR/LOC-GLIDE SLOPE switch S1. These twometers measure the deviation current and flagcurrent from either receiver. The FLAG meteralso measures the output of the RMI servoam-plifier in the radio receiver. When SERVOAMP TEST pushbutton switch S4 is pressed,it connects 27.5 volts dc to the RMI servoam-plifier and to flag meter relay K2. The flagmeter relay energizes and connects FLAG me-ter M2 to the RMI servoamplifier output of theradio receiver.

e. Compass Simulator Circuit. COMPASSSIMULATOR DS4 simulates a magnet icheading signal which is applied to the radioreceiver. The simulated magnetic heading sig-nal is also applied to Indicator, RMI ID–250A/ARN on the test set to drive the RMI card.

f. Aid Box. The aid box checks the wiringharness in an aircraft installation of Radio Re-ceiving Set AN/ARN-82, and checks the con-trol unit installed in the test set or aircraft.It also provides a quick check of the accuracyof the meters in the test set. The aid box re-ceives frequency information from the con-trol unit in the test set or aircraft. This fre-quency information lights the lamps on the aidbox in specific combinations. The aid box alsoreceives 26 volts, 400 cps from the test set orfrom the aircraft. A portion of this voltage isrectified, and then divided to specific levels.Specific levels of dc voltage are applied to themeter circuits in the test set or to the aircraftindicators. A portion of the 26 volts, 400 cpsis also used to check the audio wiring.

1-2.1. Block Diagram Functioning ofTest Set, Radio AN/ARM-92A(fig 1-1.1)

a. General. Test Set Radio, AN/ARM-92Aprovides for the complete testing of Radio

Receiving Sets AN/ARN-82 and AN/ARN-82A (receiving set) when used with externaltest equipment. The test set can also beused to test a gl ide-slope receiver , andprovides for flag and deviation loading. Theglide-slope test requires a special cablethat is not supplied with this unit. The func-tions of Test Set, Radio AN/ARM-92A are:

(1) Power distribution.(2) Phase shifting.(3) Resolver signal transmission.(4) Current measuring.(5) Compass simulation.(6) Self-test of control unit and functions

of the test set.b. Power Distribution Circuits. Control, Ra-

dio Set C-6873/ARM-82 (control unit), powerrelay K1, and power transformer T1 com-prise the power distribution circuits. Thetest set connects 27.5 volts direct current(dc) from an external power source to thecontrol unit which applies or removes the27.5 volts dc from the remaining power cir-cuits. When the control unit applies thisvoltage to the remaining power circuits, 27.5volts dc is applied to Radio Receiver R-1388/ARN-82 (radio receiver), or to the glide-slope receiver, and to power relay K1. Therelay then energizes and connects 115 volts,400 Hz to power transformer T1. Trans-former T1 steps the voltage down to 26 volts,400 Hz, which is applied to the radio receiv-er. The control unit also supplies the tuninginformation required by the radio receiver,or the glide-slope receiver.

c. Phase Shif t ing Circui ts . T h e p h a s eshifting circuits (consists of precision bear-ing transformers T2 and T3; Indicator ,Course ID-1347/ARN-82 (OBS); RECEIVERMODEL switch S5; BEARING switch S3; andBRG-OBS switch S2. These circuits areused to shift the phase of the 30-Hz refer-ence signal obtained from Radio ReceiverR-1388/ARN-82. Either the OBS resolveror precision bearing transformer T2 per-forms the phase shifting; BRG-OBS switchS2 selects the one to be used. The OBS re-solver shifts the phase of the 30-Hz refer-ence signal anywhere from 0 to 360°, preci-sion bearing transformer T2 shifts the phaseof the signal in precise 30° increments. The

Change 2 1-2.1

TM 11-6625-820-45

Figure 1-1.1. Test Set, Radio AN/ARM-92A, block diagram.

1-2.2 Change 2

TM 11-6625-820-45

exact 30° increment is selected by BEAR-ING switch S3. RECEIVER MODEL switchS5 removes transformer T3 from the circuitand adjusts the remaining circuits for phaseshifting.

d. Resolver Transmitter Circuit. Theresolver transmitter circuit consists of pre-cision bearing transformers T2 and T3;Indicator, Course ID-1347A/ARN-82 (OBS);RECEIVER MODEL switch S5; BEARINGswitch S3; and BRG-OBS switch S2. Thiscircuit supplies 400-Hz bearing informationto Radio Receiver R-1388A/ARN-82. BRG-OBS switch S2 selects either the OBS resol-ver or the simulated resolver comprised oftransformers T2 and T3. RECEIVER MOD-EL switch S5 connects transformers T2 andT3 to form a simulated resolver and switchesthe input to 400-Hz input. BEARING switchS3 selects the 30° increment equivalent tothe OBS resolver position.

e. Current Measuring Circuits. TO-FROMmeter M3 connects direct ly to the radioreceiver and measures its to-from current.DEVIATION meter M1 and FLAG meter M2are connected either to the radio receiveror to the glide-slope receiver, dependingon the position of VOR/LOC-GLIDE SLOPEswitch S1. These two meters measure thedeviat ion current and f lag current f romeither receiver. The FLAG meter alsomeasures the output of the RMI servoampli-fier in the radio receiver. When SERVO

Section II.

1-3. Power Distribution Circuits

The test set supplies al l the

AMP TEST pushbutton switch S4 is pressed,it connects 27.5 volts dc to the RMI servo-amplifier and to flag meter relay K2. Theflag meter relay energizes and connectsFLAG meter M2 to the RMI servoamplifieroutput of the radio receiver.

f. Compass Simulator Circuit. COMPASSSIMULATOR DS4 simulates a magnet icheading signal that is applied to the radioreceiver. The simulated magnetic headingsignal is also applied to Indicator, RMI ID-250A/ARN on the test set to drive the RMIcard.

g. Aid Box. The aid box checks the wiringharness in an aircraft installation of RadioReceiving Set AN/ARN-82 or AN/ARN-82Aand checks the control unit installed in thetest set or aircraft. It also provides a quickcheck of the accuracy of the meters in thetest set. The aid box receives frequencyinformation from the control unit in the testset or aircraft. This frequency informationlights the lamps on the aid box in specificcombinations. The aid box also receives 26volts, 400 Hz from the test set or from theaircraft. A portion of this voltage is recti-fied, and then divided to specific levels.Specific levels of dc voltage are applied tothe meter circuits in the test set or to theaircraft indicators. A portion of the 26volts, 400 Hz is also used to check the audiowiring.

necessarypower connections for the operation of RadioReceivers R-1388/ARN-82 or R-1388A/ARN-82 or a glide-slope receiver. Theoperation of these power circuits is des-cribed below. Refer to test set schematicdiagram (fig. 4-9 or 4-9.1) while reading thedescription in a, b, and c below.

a. The external sources of power are con-nected to J5 by Cable Assembly, Power, Elec-tr ical CX–11568/ARM–92 (power cable)

(fig. 1-2). The 27.5 volts dc is applied betweenpins A and B, the positive side to pin A,ground to pin B. The 115 volts, 400 cps is ap-plied with the low side to pin C and the highside to pin D. The connection from pin A ofJ5 is made through fuse F1 to pin Z of connec-tor P5 of the control unit (fig. 4-9). Whenthe control unit power switch is in the PWR orTEST position, the 27.5-volt dc circuit is com-pleted in pin M or H of P5. The 27.5 voltsis then routed to TB1, tie point 18. From tiepoint 18, the voltage is routed to relay K1. Thisvoltage energizes the relay K1, and the cir-

Change 2 1-3

DETAILED CIRCUIT FUNTIONING

TM 11-6625-820-45

Figure 1–2. Cable Assembly, Power, ElectricalCX-11568/ARM-92, schematic diagram.

cuits is completed for the 115 volts, 400 cpsfrom pin D of J5 through fuse F3 to trans-former T1. Transformer T1 steps down the 115(volts, 400 cps to 26 volts, 400 cps. The 26volts, 400 cps is routed to RMI connector P4,the compass simulator connector P1, and to con-nector P3 of the radio receiver. The RMI ser-voamplifier input is supplied with 26 volts, 400cps from transformer T1 through resistors R6and R7.

b. From tie point 18 of TB1, the 27.5 voltsdc is routed to connector P2 of the radio re-ceiver, and also through fuse F2 to connectorJ4 of the glide-slope receiver.

c. Tuning information from the control unitis routed to TB1, and branches off to both con-nectors P2 and J4, For further information onthe control unit, refer to TM 11–5826-226-35for Radio Receiving Set AN/ARN-82. Aschematic diagram of the control unit is in fig-ure 4-10.

1-4. Phase Shifting Circuits(fig. 4-9 and 4-9.1 )

In the test set the two circuits that shift thephase of the 30-cycle reference signal are theOBS resolver and precision bearing trans-former T2. Their operation is describedbelow. In Test Set, Radio TS-2500A/ARM-92, RECEIVER MODEL switch S5 disablesprecision bearing transformer T3 and ad-justs the circuit of transformer T2 whenever

the phase shifting mode is needed (switchposition A).

a. BRG–OBS switch S2 determines whichphase shifting circuit is used. When switch S2is in the OBS position, the OBS resolver isused to produce the desired phase shift. TheOBS indicator is the same type as used in anaircraft installation. The 30-cycle reference sig-nal is applied to the rotor of the resolver inthe OBS indicator. When the rotor is turned,the phase of the signal at stator output is shift-ed. A compass card is attached to the rotor, pro-viding an indication of the number of degreesof phase shift. This voltage is routed to theradio receiver. For more information on theOBS indicator, refer to TM 11-5826-226-35for Radio Receiving Sets AN/ARN-82 andAN/ARN-82A. A schematic diagram of theOBS indicator is shown in figure 1-3.

b. A resolver has the same electrical charac-teristics as a transformer. Therefore, a trans-former can be used to simulate a resolver. Whenswitch S2 is in the BRG position, precisionbearing transformer T2 and its switching cir-cuits are used to produce the desired phaseshift. The 30–cycle reference signal from theradio receiver is applied through switch S2 tothe primary of transformer T2. This primarywinding and resistor R3 simulate the rotor of aresolver. The phase shift through the second-ary winding of the transformer must be thesame as the phase shift in the stator windings

of the resolver. This phase shift through trans-former T2 is adjusted to 83° at a dial settingof 300° by the loading on the tertiary wind-ing. The design of the transformer is such thatthe phase shift it produces is stable with var-iations in alternating current (ac) or directcurrent through the primary winding. The com-bination of the precisely tapped secondarywindings of transformer T2 and the switchingarrangement (S3) produces the various voltageratios that correspond to the stator output of astandard resolver. Each clockwise position ofswitch S3 simulates a clockwise rotation of aresolver rotor in precise 30° increments. Withswitch S2 in the BRG position, the output volt-age path from transformer T2 is throughswitch S3, through switch S5 in Test Set,Radio TS-2500A/ARM-92, through switch S2,

1-4 Change 2

TM 11-6625-820-45

Figure 1-3. Indicator, Course ID-1347/ARN-82 or ID-1347A/ARN-82, schematic diagram.

and out to the radio receiver through pins Fand D of connector P2. In Test Set, RadioTS-2500A/ARM-92, terminals 8 and 9(stators E and G) of transformer T2 arecommon and connect to E of P6 and E of P2.In Test Set, Radio TS-2500A/ARM-92, sta-tors E and G connect to P2, pins E and G,through switches S3, S5, and S2.

1-4.1. Resolver Transmitter Circuit

(Contained in Test Set , Radio TS-2500A/ARM-92 only, fig. 4-9.1. )

Radio Receiver R-1388A/ARN-82 re-quires 400-Hz resolver signals to derivecourse deviation and to-from outputs. The

test set produces these signals either byenergizing the OBS resolver or by energiz-ing the precision bearing transformers.

a. BRG-OBS switch S2 determines whichresolver circuit is used. When switch S2 isin the OBS position, the OBS resolver isused to produce the desired course. TheOBS indicator is the same type as used in anaircraft installation. The 400-Hz referencesignal is applied to the rotor of the resolverin the OBS indicator. When the rotor isturned, the voltage of the signal at statoroutput is varied. A compass card is attachedto the rotor, providing an indication of thecourse selected. The voltage is routed tothe radio receiver. For more informationon the OBS indicator, refer to TM 11-5826-

Change 2 1-4.1

TM 11-6625-820-45

226-35 for Radio Receiving Sets AN/ARN-82and AN/ARN-82A. A schematic diagram ofthe OBS indicator is shown in figure 1-3.

b. A resolver has the same e l ec t r i ca lcharacteristics as a transformer. There-fore, a transformer can be used to simulatea resolver. When switch S2 is in the BRGposition and RECEIVER MODEL switch S5is in the B position, precision bearing trans-formers T2 and T3 and their switching cir-cuits are used to produce the desired statorvoltages. The 400-Hz reference signalfrom the radio receiver is applied throughswitches S2, S5, and S3 to the primaries oftransformers T2 and T3. These primarywindings simulate the rotor of a resolver.

The combination of the precisely tappedsecondary windings of transformers T2 andT3 and the switching arrangement (S3) pro-duces the various voltage ratios that corre-spond to the stator output of a standard re-solver. Each clockwise position of switchS3 simulates a clockwise rotation of a re-solver rotor in precise 30° increments .With switch S2 in the BRG position, the out-put voltage path from transformers T2 andT3 is through switches S5 and S2 to the radioreceiver on pins D, E, F, and GP2.

1-5. Current Measuring Circuits(fig. 4-9 and 4-9.1)

The outputs of four circuits in

of connector

the radio re-ceiver are measured in the test set. These meas-uring circuits are described below.

a. To-from current from the radio receiver isread on meter M3. TO–FROM meter M3 indi-cates the direction and amplitude of the cur-rent. Resistor R8 is a shunt resistor to extendthe range of the meter.

b. Deviation current from either the radioreceiver or the glide-slope receiver is read onmeter M1. With the switch S1 in the VOR/LOCposition, pins P, B, and M of connector P2 con-nect through switch S1 to the DEVIATIONmeter. The return path from meter M1 isthrough stitch S1 back to connector P2. Whenswitch S1 is in the GLIDE SLOPE position,meter M1 connects through switch S1 to pin T

of GLIDE SLOPE connector J4. The complet-ed path of meter M1 is through switch S1 topin V of J4.

c. Flag current from either the radio receiv-er or the glide-slope receiver is read onFLAG meter M2. When switch S1 is in theVOR/LOC (very high-frequency omni-direc-tional radio range/localizer) position, meterM2 is connected through switch S1 to pin bof P2 by the contacts of relay K2. The com-pleted path from the meter is through the oth-er set of contacts of relay K2, through switchS1 to pins c and a of P2. With the switch S1 inthe GLIDE SLOPE position, meter M2 isconnected to pin v of J4 by switch S1 throughthe contacts of relay K2. The completed pathof meter M2 is through the other contacts ofrelay K2, through switch S1 to pin J on J4.FLAG meter M2 can also be used to measurethe output current of the RMI servoamplifierin the radio receiver. When the SERVO AMPTEST switch S4 is pressed, 27.5 volts dc fromtie point 18 of TB1 is routed to the RMI (radiomagnetic indicator) servoamplifier of the radioreceiver and relay K2. When relay K2 is ener-gized, FLAG meter M2 is placed across RMIservoamplifier load resistor R5. Resistor R4 isa current-limiting resistor and diode CR1 recti-fies the RMI servoamplifier output currentthat is applied to meter M2. Diode CR2 isused to short out any voltage caused by thecollapsing field of relay K2 when switch S4is opened.1-6. Compass Simulator Circuits

(fig. 4-9 and 4-9.1)

The COMPASS SIMULATOR indicator con-tains a synchro transmitter of the same typeused with the compass in an aircraft installat-i o n . As the dial is turned, the synchrogenerates a varying vol tage from the 26volts, 400 Hz that is applied to the COMPASSSIMULATOR indicator. The output voltagefrom the synchro transmitter is routed tothe radio receiver and the RMI card to simu-late a magnetic heading. The pointer simu-lates the pointer of the compass in the air-craft.1-7. RMI Circuits

The RMI card gives an indication of simulatied magnetic heading. The simulated magnetic

Change 2 1-5

TM 11-6625-820-45

heading signal originates in the compass simu-lator, and is routed to the RMI card. The RMIneedles give an indication of the direction ofa very high-frequency omnirange (vor) station.In the test set, two needles are electricallyjumpered together. This makes the two nee-dles track together. The vor signals are routedfrom the radio receiver to the needle connec-tions on P4. If the RMI card rotates to indi-cate a magnetic heading, the needles will fol-low the card rotation to keep in the directionof the vor station. For more information on theRMI refer to TM 11–5826-211-50 for Indica-tor, Course ID–250A/ARN. The RMI is shownin figure 1–4.

1-8. Aid Box(fig. 1-5)

The aid box is primarily intended for testinga new AN/ARN-82 or AN/ARN-82A installa-tion wiring harness, but it can be used for aquick check on the test set. The main cir-cuits are as follows:

a. Light Circuitry. The light circuitry is pro-vided to indicated when a circuit is made com-plete or when i t is energized. Frequencycontrol information is given in a code by thelamps. The lamps that check the power circuitsglow when a current flows through them, in-dicating an energized circuit.

b. Meter Circuitry. The 26 volts, 400 cps isapplied to pin G of J1 and is routed to Zenerdiode CR1. Resistor R8 and Zener diode CR1form the 10-volt dc power supply for the metercircuits. Resistor R6 is a current-limiting resis-tor for the TO-FROM meter. Resistor R5 is acurrent-limiting resistor for the DEVIATIONmeter. Resistor R3 (a 51l-ohm load) and re-sistor R4 (a 1,000-ohm load) are the loadingresistors for the DEVIATION meter. Resistor

Figure 1-4. Indicator, Course ID-250A/ARN,schematic diagram.

R2 is the current-limiting resistor for the FLAGmeter, and resistor R1 is a 1,000-ohm load forthe FLAG meter.

c. Audio Circuit. Resistor R7 drops the 26volts, 400 cps to the voltage level desired,and this 400-cycle tone is fed to pin L of J2.

d. Compass RMI circuit. The signal fromthe compass simulator at pins C and D of J1is connected to the RMI needle circuit throughpins H and K of J1. This makes needle num-ber 1 (needle number 2 is not used) of the RMIfollow the rotation of the RMI card when theaid box is used to check the test set.

1-6 Change 2

TM 11-6625-820-45

Figure 1-5. Test Set, Wiring Harness, Aircraft TS-2501/ARM-92,schematic diagram.

1-7

TM 11-6625-820-45

CHAPTER 2

TROUBLESHOOTING

Section I. GENERAL TROUBLESHOOTING TECHNIQUES

Warning: Be careful when working on the115-volt, 400-cps circuit. Serious injury ordeath may result from contact with this cir-cuit.

2–1. GeneralThe general support and depot maintenance

procedures in this manual supplement the pro-cedures in the organizational maintenance man-ual. The systematic troubleshooting procedure,which begins with the operational and sec-tionalization checks that can be performed atan organizational category, is carried to a high-er category in this manual. Sectionalizing, lo-calizing, and isolating techniques used in thetroubleshooting procedures are more advanced.

2-2. Organization of TroubleshootingProcedures

a. General. The first step in servicing amalfunctioning test set is to sectionalize thefault. Sectionalization means tracing the faultto a unit or circuit. The second step is to lo-calize the fault. Localization means tracing thefault to a defective part responsible for the ab-normal condition. Some faults, such as burned-out resistors and arcing and shorted transform-ers can often be located by sight, smell, andhearing. The majority of faults, however, mustbe isolated by checking voltages and resistance.

b. Sectionalization. Listed below is a groupof tests arranged to reduce unnecessary workand to aid in tracing trouble in a malfunction-ing test set. Test Sets, Radio AN/ARM-92and AN/ARM-92A consist of five units; thetest set, the control unit, the RMI the OBSindicator and the aid box. The first step is

to locate the unit or units at fault by thefollowing methods:

(1)

(2)

Visual inspection. The purpose ofvisual inspection is to locate faultswithout testing or measuring circuits.Indications on the RMI meters, orother visual signs should be observedduring all operating modes, and anattempt should be made to section-alize the fault to a particular unit.Operational tests. Operational testsfrequently indicate the general loca-tion of trouble. In many instances,the tests will help in determining theexact nature of the fault. The inter-mediate preventive maintenancechecks and services chart (TM 11-6625-820-12) contains a list of op-erational checks which helps to sec-tionalize troubles to a unit.

c. Localization. After the trouble has beensectionalized (b above), the methods listed be-low will aid in localizing the trouble to a cir-cuit in the suspected unit. See the trouble-shooting chart for help in finding the trouble.RMI and meter indications or lack of indica-tions and operational checks provides a sys-tematic method of localizing trouble to a circuit.The procedures provided in the troubleshoot-ing charts (para 2–5 through 2–9) will provideadditional information for localizing trouble.

d. Isolation. After the trouble has been lo-calized (c above), the methods in (1) through(4) below will help in isolating the trouble to adefective circuit element.

(1) Resis tance measurements . Res i s t -ance measurements are used to

Change 2 2-1

TM 11-6625-820-45

check for continuity and to check thevalue of resistance in a circuit. Forthese checks, use Multimeter ME-26(*) /U, or equivalent.

Caution: Be sure that the multim-eter is not placed across a meter inthe test set. The current from theohmmeter might damage the micro-ampere movement of a meter of thetest set.

(2)

(3)

Voltage measuremen t s . V o l t a g emeasurements are used to check tosee if the proper amount of voltage isbeing routed through the test set andaid box. For these measurements, useMultimeter ME–26(*)/U, or equiva-lent.Intermittent troubles. In all thesetests, the possibility of intermittenttroubles should not be overlooked. Ifpresent, this type of trouble may oftenbe made to appear by tapping or jar-ing the equipment. Make a visual in-

Test Equipment

Modulator MD-83A/ARNOutput Meter TS-585(*)/Ua

Multimeter ME-26(*)/Ub

Oscilloscope AN/USM-140AVoltmeter, Meter ME-30A/U and Voltmeters,

Electronic ME-30(*)/Uc

Test Set, Resolver AN/ASM-101Test Set, Indicator Course AN/ASM-110Meter Test Set TS-682A/GSM-lBridge, Resolver, Gertsch model RB-4C-4R;

Singer Company, Los Angeles, California

(4)

spection of the wiring and connec-tions.Resistor color code. The resistor colorcode diagram (fig. 4–8) is providedto aid maintenance personnel in deter-mining the value and tolerance of re-sistors.

2-3. Test Equipment RequiredThe following chart lists equipment required

for troubleshooting Test Set, Radio AN/ARM-92 or AN/ARM-92A. It also lists the assoc-iated technical manuals.

a. Make test equipment connections withcare so that shorts will not be caused by ex-posed test equipment connectors. Tape orsleeve (spaghetti) test prods or clips as neces-sary to leave as little exposed metal as need-ed to make contact to the circuit under test.

b. Observe polarity; a negative ground is re-quired on the 27.5-volt dc line. The low sideof the ac line is also grounded.

c. The following test equipment is required:

Technical manual

TM 11-6625-588-15TM 11-5017TM 11-6625-200-12TM 11-6625-535-15TM 11-6625-320-12

TM 11-6625-492-12

TM 11-2535B

Common name

Vor modulatorOutput meterMultimeterOscilloscopeVtvm

Resolver test setIndicator test setMeter calibratorResolver bridge

a Indicates Output Meters TS-585A/U, TS-585B/U, TS-585C/U, and Audio Level Meter TS-585D/U.b Indicates Multimeter ME-26A/U, ME-26B/U, and ME-26C/U.c Indicates Voltmeter, Meter ME-30A/U and Voltmeters, Electronic ME-30B/U and ME-30C/U.

Section Il. TROUBLESHOOTING PROCEDURES

2-4. General 2-5. Troubleshooting Aid BoxThe troubleshooting procedures are divided

into two parts. The first part (paras 2–5 and Because of the simplicity of the aid box cir-2-6) gives procedures to troubleshoot the aid cuitry, any trouble may be quickly isolated bybox. The second part (paras 2-7 through 2-9) the following checks:gives procedures to troubleshoot the control a. Remove the bottom of the aid box by re-unit, the RMI the OBS indicator, and the moving the six screws on the bottom of the aidtest set. box.

2-2 Change 2

TM 11-6625-820-45

b. Connect P2 and P3 of the test set to theaid box.

c. Connect the test set to a 27.5 volt dc pow-e r source, a n d a 115-volt, 400-cps powersource.

d. Set the power switch on the control unitto PWR.

e. Connect the dc lead of the multimeterto the junction of Zener diode CR1 and re-sistor R8. Connect the COMMON lead to theanode of Zener diode CR1.

f. The multimeter should indicate 10 volts dc±0.05. If the indication is improper, replacethe defective Zener diode CR1.

g. All other circuits in the aid box may bechecked by using the resistance chart in para-graph 2–6. Remove all equipment connected tothe aid box before at tempting resis tancemeasurements. When an improper resistancereading is obtained, refer to the schematic di-agram in figure 1–5 to isolate the trouble.

2-6 . Res is tance Char t for A id Box

Multimeter connection

From

A of J2J of J2J of J2J of J2J of J2J of J2J of J2J of J2J of J2J of J2A of J2A of J2L of J2D of J1C of J1A of J2A of J2A of J2A of J2

To

a of J2X of J2n of J2Y of J2b of J2C of J2B of J2P of J2N of J2E of J2m of J2Z of J2G of J1H of J1K of J1t of J2k of J2p of J2f of J2

Proper indication(ohms)

22,900 ± 2,29000001,000 ± 100511 ±511,000 ± 1000036,500 ± 3,65042,500 ± 4,2501,500 ± 16000160 ±20160 ±20160 ±20160 ±20

Multimeter connection

From

A of J2A of J2A of J2A of J2A of J2A of J2A of J2A of J2A of J2A of J2R of J2K of J2G of J1

To

W of J2g of J2V of J2h of J2U of J2i of J2T of J2j of J2S of J2X of J2X of J2X of J2E of J1

Proper indication(ohms)

2-7. Troubleshooting Control Unit, RMIOBS Indicator, and Test Set

a. Perform the general support testing pro-cedures for the aid box in paragraph 4–7. Ifthe general support testing procedures indicatetrouble, perform the troubleshooting proce-dures described in paragraph 2-5.

b. Connect the test set to the aid box andexternal power as shown in figure 2-1.

c. Set the power switch on the test set con-trol unit to OFF.

d. Set the VOR/LOC-GLIDE SLOPE switchon the test set to VOR/LOC. (All other switch-es and controls may be set in any position. )

e. Perform the procedures in the trouble-shooting chart in paragraph 2-8. This chartgives various operational procedures for thetest set. The proper indication for each op-erational procedure is then given. If the equip-ment produces an improper indication, thechart lists the probable trouble and, in theCorrection column, suggests how to isolate thetrouble.

Change 2 2-3

TM 11-6625-820-45

Figure 9-1. Equipment setup to test control unit, RMI OBS indicator, and test set.

2-4 Change 2

TM 11-6625-820-45

Figure 2–2. Test Set, Radio TS–2500/ARM–92, front panel.

Change 2 2-4.1

TM 11-6625-820-45

Figure 2–2.1 Test Set, Radio TS-2500A/ARM–92, front panel.

2-4.2 Change 2

TM 11-6625-820-45

Figure 2-3. Rear side of Test Set, Radio TS–2500/ARM-92, front panel.

Change 2 2-5

TM 11-6625-820-45

Figure 2–3.1 Rear side of Test Set, Radio TS–2500A/ARM–92, front panel.

2-6 Change 2

TM 11-6625-820-45

Figure 2–4. Bottom view of Test Set, Radio TS-2500/ARM-92, front panel.

Change 2 2-6.1

TM 11-6625-820-45

Figure 2–4.1 Bottom view of Test Set, Radio TS–2500A/ARM-92, front panel.

Figure 2-5. Terminal board number 2 (TB2).

2-6.2 Change 2

TM 11-6625-820-45

Figure 2-6. Aid box, front panel.

2-7

TM 11-6625-820-45

2-8

Figure 2–7. Parts location of aid box.

T M 1 1 - 6 6 2 5 - 8 2 0 - 4 5

Figure 2-8. Power cable.

2-9

Figure 2-8.

TM

1

1-6

62

5-8

20

-45

2-10

TM

11-6625-820-45

Change

2 2-11

TM

11-6625-820-45

2-1

2

TM

1

1-6

62

5-8

20

-45

2-1

3

TM

1

1-6

62

5-8

20

-45

2-

14

TM

1

1-6

62

5-8

20

-45

2-1

5

TM

1

1-6

62

5-8

20

-45

2-1

6

TM

11-6625-820-45

Ch

ang

e 2

2

-17

TM

11-6625-820-45

2-18 C

hange 2

TM

11-6625-820-45

Ch

ang

e 2

2

-19

TM

11

-66

25

-82

0-4

5

2-2

0

Ch

ang

e 2

TM 11-6625-820-45

Figure 2-9. Equipment setup to test precision BEARING circuit.

2–9. Dc Resistances of Transformersand Relay Coils

Change 2 2-21

TM 11-6625-820-45

CHAPTER 3

REPAIR AND ALIGNMENT

Section I.

3-1. General Parts ReplacementTechniques

The following general precautions shouldbe observed when replacing parts in this equip-ment.

a. When soldering or unsoldering compo-nents, solder quickly to allow as little heat con-duction as possible, Whenever wiring permits,use a heat sink (such as a long-nosed pliers) be-tween the solder joint and the component. Useapproximately the same length and dress ofleads as used originally.

b. Use a pencil-type iron with a 25-watt max-imum capacity. If the iron must be used withac, use an isolation transformer between theiron and the line. Check soldering irons forshorts to the iron tip before using.

c. Whenever an electrical part such as a re-sistor or diode is to be removed, note the exactposition of the component before removing it.Replace the component in the same position.

3-2. Removal and Replacement Techniques

The procedures for removal and disassemblyof the units in the test set are described in para-graph 3-3. The corresponding replacement, re-assembly, and lubrication techniques are de-scribed in paragraph 3-4. The procedures fordisassembly of the aid box are described inparagraph 3-5. The corresponding reassemblytechniques are described in paragraph 3-6.

3-3. Removal and Disassembly Techniquesfor Test Sets, Radio TS-2500/ARM-92and TS-2500A/ARM-92

a. Removal of Test Set Front Panel(1) Remove the 13 screws from

meter of the front panel.the peri-

REPAIRS

(2) Lift the front panel away from thetest set.

(3) Disconnect the power cable from thechassis.

Note. To allow enough slack to conven-iently work on the test set , the pendantcables may be pulled through the portholein the bottom of test set.

b. Removal of Control Unit.

(1) Loosen the four Dzus fasteners.(2) Pull the control unit away from the

front panel of the test set.(3) Disconnect the cable attached to the

control unit.

c. Disassembly of Control Unit. Refer toTM 11–5826-226-35 for disassembly pro-cedures of Control, Radio Set C-6873/ARN–82.

d. Removal of OBS Indicator.

(1) Remove the four screws that hold theOBS indicator to the front panel ofthe test set.

(2) Pull the OBS indicator away from thefront panel of the test set.

(3) Disconnect the cable attached to theOBS indicator.

e. Disassembly of OBS Indicator. Refer toTM 11–5826-226-35 for disassembly proce-dures of Indicator, Course ID-1347/ARN-82,or ID-1347A/ARN-82.

f. Removal of RMI

(1)

(2)

(3)

Remove the four screws that hold theRMI to the front panel of the test set.Pull the RMI away from the frontpanel of the test set.Disconnect the cable attached to theR M I

Change 2 3-1

TM 11-6625-820-45

g. Disassembly of RMI. Refer to TM 11–5826-211-50 for disassembly procedures forIndicator, Course ID-250A/ARN.

h. Removal of COMPASS SIMULA-TOR indicator.

(1)

(2)

(3)

(4)

Remove the test set front panel (aabove).Remove the three screws that hold theCOMPASS SIMULATOR indicator tothe front panel of the test set.Pull the COMPASS SIMULATORindicator away from the front panel.Disconnect the cable attached to theCOMPASS SIMULATOR indicator.

i. Disassembly of COMPASS SIMULATORindicator (fig. 3-1).

(1)

(2)

(3)

(4)

(5)

(6)(7)

(8)

(9)

(10)

(11)

(12)

Remove four screws (30) and fourlockwashers (29) from connector P1(28).Pull connector P1 (28) away fromrear housing (23) to allow enoughspace to unsolder leads attached toconnector. Label these leads to identi-fy them for reassembly. Remove gas-ket (27).Set COMPASS SIMULATOR indica-tor down on a flat surface.Remove eight screws (25) and eightlockwashers (24).Pull front cover (5) away from rear

housing (23).Remove gasket (22).Separate front cover (5) from syn-chro housing (17).

Note. To remove dial window (9), pushcarefully on front side of dial window (9)to r emove i t f r om f ron t cove r ( 5 ) andwindowseal (8).

Loosen two setscrews (2 and 3). Re-move knob (1) and spring washer(4).Pull out drive gear (7). Remove shaftsleeve (6).Pull needle (11) straight off shaft ofsynchro B1 (21).Rotate synchro gear (13) until set-screw (14) lines up with hole in small-er rim of synchro housing (17). Loos-en this setscrew.Repeat step in (11) above to loosensetscrew (14).

3-2 Change 2

(13)

(14)

(15)

Remove dial retainer (10) and dial(12).Remove synchro gear (13) and idlergear (16).Remove three screws (20), three lock-washers (19), and three synchroclamps (18).

(16) Pull synchro B1 (21) off synchrohousing (17).

j. Removal of FLAG Meter.(1)

(2)

(3)

(4)

Remove the test set front panel ( aabove).Disconnect the two wires attached tothe meter. Label these wires for iden-tification when replacing the meter.Remove the four nuts that hold themeter to the test set.Pull the meter out of the front panel.

k. Removal of DEVIATION Meter.(1) Remove the test set front panel ( a

above).(2) Disconnect the two wires attached to

the meter. Label these wires for iden-tification when replacing the meter.

(3) Remove the four nuts that hold themeter to the test set.

(4) Pull the meter out of the front pan-el.

l. Removal of TO-FROM Meter.(1)

(2)

(3)

(4)

Remove the test set front panel ( aabove).Disconnect the two wires attached tothe meter. Label these wires for iden-tification when replacing the meter.Remove the four nuts that hold themeter to the test set.Pull the meter out of the front panel.

3-4. Replacement, Reassembly, andLubrication Techniques for Test Sets,Radio TS-2500/ARM-92 andTS-2500A/ARM-92

a. Replacement of TO-FROM Meter.(1) Place the meter back in the front

panel.(2) Replace the four nuts to hold the

meter to the front panel.(3) Connect the two wires to their proper

terminal on the meter.(4) Replace the test set front panel ( l be-

low).

b. Replacement of Deviation Meter.(1) Place the meter back in the front

panel.(2) Replace the four nuts to hold the

meter to the front panel.(3) Connect the two wires to their proper

terminal on the meter.(4) Replace the test set front panel ( l

above).

c. Replacement of FLAG Meter.(1)

(2)

(3)

(4)

Place the meter back in the frontpanel.Replace the four nuts to hold themeter to the front panel.Connect the two wires to their properterminals on the meter.Replace the test set front panel ( labove).

d. Reassembly of COMPASS SIMULATORIndicator (fig. 3-l).

(1)

(2)

(3)(4)

(5)

(6)(7)(8)

(9)

(lo)

(11)

Replace synchro B1 (21) to synchrohousing (17).Replace three synchro clamps (18),three lockwashers (19), and threescrews (20).Replace synchro gear (13).Rotate synchro gear (13) until thesetscrew (15) lines up with the holein the smaller rim of synchro housing(17). Tighten this setscrew.Repeat step in (4) above to tightensetscrew (14).Replace idler gear (16).Replace dial (12) and retainer (10).Push needle (11) straight on the shaftof synchro B1 (21) until it is prop-erly in place. Align the COMPASSSIMULATOR indicator (para 3-10).Replace shaft sleeve (6). Lubricate in-side of shaft sleeve (6) with DowCorning Stopcock grease Replacedrive gear (7).Replace spring washer (4). Replaceknob (1) and tighten two setscrews(2 and 3).Replace front cover (5) to synchrohousing (17).

Note . If dial window (9) has been re-moved, replace the window by very carefullypushing it back into the front cover (5) be-fore replacing the front cover.

(12)

(13)

(14)

(15)

(16)

(17)

TM 11-6625-820-45

Replace gasket (22) to rear housing(23).

Replace front cover (5) to rear hous-ing (23).

Replace eight lockwashers (24) andtighten eight screws (25).

Replace gasket (27).

Solder the leads to the proper pointson connector P1 (28).

Replace four lockwashers (29) andtighten four screws (30).

e. Replacement of COMPASS SIMULATORIndicator.

(1)

(2)

(3)

(4)

Connect P1 to the COMPASS SIMU-LATOR Indicator.

Replace the COMPASS SIMULATORIndicator in the front panel.

Replace the three screws and nuts, tohold the COMPASS SIMULATORIndicator to the front panel.

Replace the test set front panel ( 1below) .

f. Reassembly and Lubrication of RMI. Re-fer to TM 11–5826-211-50 for reassembly andlubrication procedures for Indicator, CourseID-250A/ARN.

g. Replacement of RMI.

(1) Connect P4 to the RMI connector.(2) Replace the RMI in the front panel.(3) Replace the four screws to hold the

RMI to the front panel.(4) Replace the test set front panel ( l

below) .

h. Reassembly and Lubrication of OBS Indi-cator. Refer to TM 11-5826-226-35 for re-assembly and lubrication procedures for Indica-tor, Course ID-1347/ARN-82 or ID-1347A/ARN-82.

i. Replacenwnt of OBS Indicator.( l )(2)

(3)

(4)

Connect P6 to the OBS connector.Replace the OBS indicator in the frontpanel.Replace the four screws, to hold theOBS indicator to the front panel.Replace the test set front panel ( lbelow).

Change 2 3-3

TM 11-6625-820-45

Figure 3-1. COMPASS SIMULATOR Indicator, exploded view.

3 - 4

TM 11-6625-820-45

j. Reassembly and Lubrication of ControlUnit. Refer to TM 11-5826-226-35 for reas-sembly and lubrication procedures for Control,Radio Set C-6873/ARN-82.

k. Replacement of Control Unit.(1) Connect P5 to the control unit con-

nector.(2) Replace the control unit in the front

panel.(3) Tighten the four Dzus fasteners.

l. Replacement of Front Panel.(1) Connect the power cable to J5.(2) Place the front panel back in the

lower carrying case. Be sure no ca-bles are pinched between the chassisand the carrying case.

(3) Replace the 13 screws in the perime-ter of the front panel.

3-5. Disassembly Techniques for Test Set,Wiring Harness, AircraftTS-2501/ARM-92

Remove the bottom panel of the aid box asfollows:

a. Remove the six screws that hold the bot-tom panel in place.

b. Lift the bottom panel away.

3-6. Reassembly Techniques for Test Set,Wiring Harness, AircraftTS-2501/ARM-92

Replace the bottom panel of the aid box asfollows :

a. Place the bottom panel on the aid box.b. Replace the six screws, to hold the bottom

panel in place.

Section Il. ALIGNMENT

3-7. GeneralAlignment procedures for Test Sets, Radio

AN/ARM-92 and AN/ARM-92A are given inparagraphs 3-9 through 3-13. The precisionbearing alignment is given in paragraph 3-9.Alignment of the COMPASS SIMULATOR in-dicator is given in paragraph 3-10. Refer-ences to the alignment procedures are givenfor the OBS indicator, RMI and control unitin paragraphs 3-11 through 3-13. Refer-ences to the test equipment required aregiven in paragraph 3-8.

3-8. Test Equipment Required forAlignment

Refer to paragraph 2-3 for a list of the testequipment required for alignment procedures.

3-9. Precision Bearing Alignment

a. Remove the test set front panel (para3-3(a).

b. A special cable is required for precisionbearing alignment. Refer to paragraph 4-4 forconstruction details of this cable.

c. Connect the equipment as shown in fig-ure 2–9, and calibrate the resolver test set. (Re-fer to TM 11–6625-492-12 for calibration ofTest Set, Resolver AN/ARM-101.)

d. Disconnect the MOD OUTPUT connec-tor of the vor modulator from the VAR con-nector of the resolver test set.

e. Connect the INPUT of the vacuum-tubevoltmeter (vtvm) to the VOLTMETER con-nector on the resolver test set.

f. Set the function switch on the resolvertest set to SET ORZ.

g. Adjust the INPUT LEVEL control onthe resolver test set for 4.25-volt indication ofthe vtvm.

h. Remove the INPUT of the vtvm fromthe VOLTMETER connector, and connect itto the OUTPUT connector on the resolver testset.

i. Set the VOR/LOC-GLIDE SLOPE switchon the test set the VOR/LOC.

j. Set the BEARING selector switch on thetest set to 300.

k. Unlock potentiometer R1 located behindthe front panel of the test set.

l. Alternately adjust the AMP.BAL. con-trol on the resolver test set and potentiometerR1 in the test set to obtain the least possiblesignal amplitude (minimum null) as observedon the oscilloscope.

Note. A S the null is approached, increase the verticalgain of the oscilloscope.

Change 2 3-5

TM 11-6625-820-45

m. Lock potentiometer R1 shaft.n. If aligning Test Set, Radio TS-2500/

ARM-92, disconnect the equipment and re-place the test set front panel. Omit steps othrough z.

o. Disconnect the test set from the resol-ver test setup (fig. 2-9). Connect the testset and the resolver br idge as shown infigure 3-2. Use the cable fabricated in para-graph 4-4 (fig. 4-1.2).

p. Disconnect the wire to the wiper con-nection of wafer H of switch S3 (fig. 3-3).

q. Connect jack J7 of the fabricated cableto the pin from which the wire was removedin step p.

r. Set the test set BEARING switch to300 and the resolver bridge angle switch to0 degree.

s. Adjust the oscilloscope gain controls toobtain a line of approximately 20 degreesslope from the horizontal (disregard anyballooning).

t. With grease pencil or equivalent, drawthe slope line on the oscilloscope face; thisis the maximum negative angle. Draw al ine of the same slope but the opposi tedirection from the horizontal line; this is themaximum positive angle.

u. Disconnect the jumper from J7 of thefabricated cable to the test set.

Figure 3-2. TS-2500A/ARM-92 precision BEARING alignment.

3-6 Change 2

TM 11-6625-820-45

v. Reconnect the wire disconnected instep p.

w. Rotate the test set BEARING switchand the resolver bridge angle switch simul-taneously in 30-degree steps and note theamount of error and the direction the line onthe oscilloscope slopes.

x. If the error exceeds the limit set instep t, r e f e r t o t he t r ans fo rmer errorcorrection chart in paragraph 3-9.1.

y. Repeat s teps c t h r o u g h y u n t i l a l lerror limits are met.

z. Disconnect the equipment and replacethe front panel.

Figure 3-3. TS-2500A/ARM-92 switch S3wafer and pin designation.

3-9.1. Transformer Error CorrectionChart

Symptom Corrective action

Positive error at 90 degrees

Positive error at 60 degreesthan error at 90 degrees.

Positive error at 60 degreesthan error at 90 degrees.

g r e a t e r

less

No or small negative error at 60d e g r e e s .

Negative error at 60 degrees greaterthan error at 90 degrees.

Add resistance between terminals 9 and 10 ofT2 to reduce error at 60 degrees; then addresistance between terminals 10 and 11 of T2to reduce error at 90 degrees.


Add resistance between terminals 10 and 11of T2 to reduce error at 90 degrees; thenadd resistance between terminals 10 and 11 ofT1 to reduce error at 60 degrees.

Add resistance between terminals 10 and 11 ofT1 to reduce error at 60 degrees; then addresistance between terminals 10 and 11 ofT2 to reduce error at 90 degrees.

Negative error at 90 degrees

Negative error at 60 degrees greaterthan error at 90 degrees.

Negative error at 60 degrees lessthan error at 90 degrees.



Change 2 3-7

TM 11-6625-820-45

No or small positive error at 60 Add resistance between terminals 9 and 10 ofd e g r e e s . T1 to reduce error at 90 degrees: then add

resistance between terminals 9 and 10 of T2to reduce error at 60 degrees.

Posit ive error at 60 degrees greater Add resistance between terminals 9 and 10 ofthan error at 90 degrees. T2 to reduce error at 60 degrees; then add

resistance between terminals 9 and 10 of T1to reduce error at 90 degrees.

No error at 90 degrees

Positive error at 60 degrees. Add resistance between terminals 9 and 10 ofT2 to reduce error at 60 degrces: then addresistance between terminals 9 and 10 of T1to correct error induced at 90 degrees.

Negative error at 60 degrees. Add resistance between terminals 10 and 11 ofT2 to reduce error at 60 degrees: then addresistance between terminals 10 and 11 of Tlto correct error induced at 90 degrees.

1

3-10. COMPASS SIMULATOR IndicatorAlignment

a. Remove the test set front panel (para 3-3a).

b. Connect the test set to a 27.5-volt dc pow-er source, and a 115-volt, 400-cps power source.

c. Set the power switch on the control unitto PWR. (All other controls and switches onthe control unit and test set may be in anyposition.)

Caution: In the following steps, remove thevtvm power cord from ground to eliminatethe possibility of shorting across the externalpower source.

d. Connect the vtvm between pins C and Dof connector P3 of the test set pendant cable.

e. With the compass simulator control, ro-tate the COMPASS SIMULATOR indicatorfor a null indication on the vtvm.

Note. A 360° rotation of the COMPASS SIMULA-TOR indicator will produce two nulls on the vtvm. Todetermine the correct null, measure the ac voltage be-tween pins C and G of connector P3. This ac voltagewill be less than 26 volts ac when the correct null isfound.

f. With the COMPASS SIMULATOR indi-cator set to the correct null, perform the fol-

lowing procedure to zero the COMPASS SIM-ULATOR indicator needle.

(1)

(2)

(3)

(4)

(5)

(6)

Remove the rear housing of the COM-PASS SIMULATOR indicator.Loosen the three screws that holdsynchro B1 to the housing.Rotate the entire synchro until theCOMPASS SIMULATOR indicatorneedle points exactly to N.Tighten the three screws that holdsynchro B1 to the housing.Set the power switch on the controlunit to OFF.Replace the rear housing of theCOMPASS SIMULATOR indicator.

g. Disconnect the equipment, and replacethe front panel on the test set.

3-11. OBS Indicator Alignment

Refer to TM 11–5826-226-35 for alignmentprocedures of Indicator, Course ID-1347/ARN-82, and ID-1347A/ARN-82.

3-12. RMI Alignment

Refer to TM 11–5826-211-50 for align-ment procedures of Course Indicator ID–250A/ARN.

3-8 Change 2

TM 11-6625-820-45

CHAPTER 4

GENERAL SUPPORT TESTING PROCEDURES AND DEPOT

OVERHAUL STANDARDS

4-1. General

a. Testing procedures are prepared for useby general support and depot maintenanceshops responsible for general support anddepot maintenance of electronic equipment todetermine the acceptability of repaired elec-tronic equipment. These procedures set forthspecific requirements that repaired electronicequipment must meet before it is returned tothe using organization. The testing proceduresare to be used for both general support testingprocedures and depot overhaul standards. Ap-plicable procedures of the Army depots per-forming these tests and the general standardsfor repaired electronic equipment given in TBSIG 355-1, TB SIG 355-2, and TB SIG 355-3form a part of the requirements for testingthis equipment. A summary of the perform-ance standards is given in paragraph 4-16.

b. Comply with the instructions precedingthe body of each chart before proceding to thechart. Perform each test in sequence. Do notvary the sequence. For each step, perform allthe actions required in the Control settingscolumns; then perform each specific test pro-cedure, and verify it against its performancestandard.

4-2. Test Equipment, Tools, and Materials

All test equipment, tools, materials, and oth-er equipment required to perform the testingprocedures given in this section are listed inthe following charts and are authorized underTA–11–17, Signal Field Maintenance Shops,and TA–11–100(11–17), Allowances of SignalCorps Expendable Supplies for Field Mainte-nance Shop, Continental United States.

Nomenclature Federal stock number Technical manual

Modulator MD-83A/ARN

Output Meter TS–585(*)/U

Voltmeter, Meter ME–30A/U and Voltmeter,Electronic ME-30(*)/U

Multimeter ME-26(*)/U

Test Set, Resolver ANAN/ASM-101

Oscilloscope AN/USM-140A

Meter Test Set TS–682A/GSM-1

6625-539-85636625–244-0501

6625-669-0742

6625-542-6407

6625-086-7844

6625-987-6603

6625-669-0747

TM 11-6625-588-15TM 11-5017

TM 11-6625-320-12

TM 11-6625-200-12

TM 11-6625-492-12

TM 11-6625-535-15

TM 11-2535B

4-1

TM 11-6625-820-45

b. Tools. All tools required are containedin Tool Kit, Electronic Equipment TK–105/G,Federal Stock No. 5180-610-8177.

c. Materials.(1) 1/4-inch barrel diameter.(2)

(3)

(4)

(5)

(6)(7)(8)(9)

Telephone plug (1/4-inch diameterbarrel).

Wire, copper, insulated, stranded #22 AWG (40 feet long).Connectors (3), Bendix PTOlA-20-40P(SR).Connector, Bendix PTO1A-12-10P(SR).Clamp MS3057-10A.Connector MS3106A-18S-1S.Connector MS3116A-18-32SW.Binding posts (7) Superior ElectricCompany DF 30RC.

(10) Spaghetti, 3/4-inch diameter (5.5feet long).

(11) Small enclosed metal box 3 x 4 x 5inches.

4-3. Test Facilities

Primary power requirements are 27.5 voltsdc at 33 watts and 115 volts, 400 cps at 92watts. Temperature, humidity, and atmos-pheric pressure are not critical.

4-4. Fabricated Cable ConstructionDetails

Fabricated cables are required to connectthe test set to Test Set, Resolver AN/ASM-101 and Test Set, Indicator, Course AN/

ASM-110. Refer to figures 4-1, 4-1.1, and4-1.2 and construct the cables as describedbelow.

a. Resolver Test Set and Indicator TestSet Cables.

(1)

(2)

(3)

(4)

(5)

Solder six 2-foot lengths of # 22AWG stranded, insulated wire topins C, D, E, F, G, and H of eachmale connector P1.Label the loose ends of the six wireswith the pin number to which eachwire is connected.Slip a 2-inch length of spaghetti overthe loose ends of the six wires.Place clamp MS3057-10A over theend of the spaghetti on the resolvertest set cable.Connect the loose ends of the sixwires to the pins of the J1 femaleconnectors as shown in figures 4-1and 4-1.1.

Figure 4-1. Fabricated cable to resolver test set,construction details.

Figure 4-1.1. Fabricated cable to indicator test set, construction details.

4-2 Change 2

TM 11-6625-820-45

(6) Tighten the clamps around the J1connectors on each cable.

b. Resolver Bridge Cable.(1)

(2)

(3)

(4)

(5)

Solder s ix 2-foot lengths of # 22AWG stranded insulated wire to pinsC, D, E, F, G, and H of male con-nector P1.Solder two 2-foot lengths of # 22AWG s t r anded i n su l a t ed w i r e t opins G and E of male connector P2.Label the loose ends of the six wireswith the pin number to which eachwire is connected.Sl ip a 2- inch length of spaghet t iover the loose end of the eight wires.Mount and label seven binding postson a small enclosed metal box (fig.3-2).

(6)

(7)

(8)

Connect a 21.5-kilohm, ±1%, 1/2-watt resistor from binding post J6 tobinding post J7.Connect a 21.5-ohm, ±1%, 1/2-wattr e s i s t o r f r o m b i n d i n g p o s t J 5 t obinding post J7.Connect the loose ends of the eightwires to the binding posts as shownin figure 4-1.2.

4-5. Modification Work Orders

The performance standards listed in thetests (paras 4–6 through 4-15) assume that themodification work orders, if any, have beenperformed. A listing of current modificationwork orders will be found in DA Pam 310-4.

Figure 4-1.2. Fabricated cable to resolver bridge, construction details.

Change 2 4-2.1

Figure 4-6.

TM

11-6625-820-45

4-3

Figure 4-2.

Change

2

TM

1

1-6

62

5-8

20

-45

4-4

Figure 4-8.

TM

11-6625-820-45

4-

7

TM 11-6625-820-45

4 - 8 C h a n g e 2

Figure 4-3. Control unit test.

Figure 4-10.

TM

11-6625-820-45

4-11

Figure 4-4.

4-1

2

Ch

ang

e 2

TM

1

1-6

62

5-8

20

-45

Ch

ang

e 2

4

-15

TM

1

1-6

62

5-8

20

-45

TM 11-6625-820-45

Figure 4-5. Test set compass simulator and Indicator, RMI ID-250A/ARN test.

4-16 Change 2

Figure 4-14.

TM

11-6625-820-45

4-1

9

Figure 4-7.

TM

11-6625-820-45

4-20C

hange 2

TM 11-6625-820-45

Checkpoint

kilocycle selectorsto 108.00 VOLcontrol on controlunit set fullyclockwise.

(3)

(4)

(6)

(6)

(7)

Megacycle and kilo-cycle selectors setto 109.05.





Per fo rmance s t anda rd

light. The 26 VAC PWRand LOC PWR lamps onthe aid box light. Thecontrol unit panel lampslight. The 1.0 FREQSELECT (MC) lampsA and D on the aid boxlight. The 0.1 FREQSELECT (MC) lampsB and E on the aid boxlight. The 0.01 FREQSELECT (MC) lamp Bon the aid box lights. TheFLAG meter indicates250 microamperes ±15.The DEVIATION meterindicates 75 microam-peres ±5 to the rightof 0. The TO-FROMmeter indicates 500 mi-croamperes ±25 to theleft of 0. TS-585A/Uindicates 100 milliwatts±15.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand E, and 0.1 FREQSELECT (MC) lampsB and E light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Band E, 0.1 FREQ SE-LECT (MC) lamps A andB, and 0.01 FREQ SE-LECT (MC) lamp Blight.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand B, and 0.1 FREQSELECT (MC) lampsA and B light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand C, 0.1 FREQ SE-LECT lamps (MC) Aand C, and 0.01 FREQSELECT lamp (MC)B light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Band C, 0.1 FREQ SE-LECT lamps (MC) Aand C light.

Checkpoint

(8) Megacycle and kilo-cycle selectors setto 114.30.

(9) Megacycle and kilo-cycle selectors Setto 115.36.

(10) Megacycle and kilocycle selectors seto 116.40.







The LOC PWR, 26 VACPFR, 1.0 FREQSELECT (MC)lamps B and D, 0.1FREQ SELECTlamps (MC) B and C,0.01 FREQ SELECT(MC) lamp B, and

The LOC PWR, 26VAC PWR, 1.0FREQ SELECT(MC) lamps C andD, 0.1 FREQSELECT (MC)lamps B and C light.

The LOC PWR, 26VAC PWR, 1.0FREQ SELECT(MC) lamps C andE, 0.1 FREQSELECT (MC) lampsB and D, and 0.01FREQ SELECT(MC) lamp B light.

The LOC PWR, 1.0FREQ SELECT(MC) lamps D andE, and 0.1 FREQSELECT (MC)lamps B and D.light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand D, 0.1 FREQ SE-LECT (MC) lamps B, C,and D, 0.01 lamp B, andCOMM lamp light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand E, 0.1 FREQ SE-LECT (MC) lamps C

a n d

and D, and COMM lamplight.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Band E, 0.1 FREQ SE-LECT (MC) lamps Cand E, 0.01 FREQ SE-LECT (MC) lamp B, andCOMM lamp light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand B, 0.1 FREQ SE-LECT (MC) lamps Cand E, and COMM lamplight.

4-23

lamp lights.

TM 11-6625-820-45

Checkpoint







(22) TS-585A/U con-nected to the AU-DIO terminals onthe test ret.

(23) VOL control on thecontrol unit setfully counterclock-wise

Performance s t a n d a r d Checkpoint

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Aand C, 0.1 FREQ SE-LECT (MC) lamps Dand E, 0.01 FREQ SE-LECT (MC) lamp B,GS/LOC ON lamp, andCOMM lamp light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Band C, 0.1 FREQ SE-LECT (MC) lamps Dand E, and COMM lamplight.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Band D, 0.1 FREQ SE-LECT (MC) lamps Aand D, 0.01 FREQ SE-LECT (MC) lamp B,and COMM lamp light.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Cand D, 0.1 FREQ SE-LECT (MC) lamps Aand D, and COMM lamplight.

The LOC PWR, 26 VACPWR, 1.0 FREQ SE-LECT (MC) lamps Cand E, 0.1 FREQ SE-LECT (MC) lamps Aand E, 0.01 FREQ SE-LECT (MC) lamp B,GS/LOC ON lamp, andCOMM lamp light.

The LOC PWR, 26 VAC,PWR, 1.0 FREQSELECT (MC)lamps C and E, 0.1FREQ SELECT(MC) lamps A andE, and COMMlamp light.

No less than 25 milliwattsindicated on TS–585A/U.

Zero Milliwatts indicatedon TS-585A/U.

(24) Power switch on thecontrol unit set toTEST.


TEST lamp on the aidbox lights.

c. OBS Indicator and Test Set PrecisionBEARING Test.

Checkpoint

(1) OBS indicator ad-justed for a nullindication on AN/USM-140A.

(2) BRG-OBS switchset to BRG, andthe BEARINGswitch set to 300.

(3) TS-2500A/ARM-92only.

(a) Indicator testset SYNCHROSELECTOR onEZ SYNCHROMETER zeroed.

(b) OBS courseindex rotatedcounterclock-wise.

(c) Indicator testset SYNCHROSELECTOR onEZ, SYNCHROMETER zeroed.

(d) OBS courseindex rotatedcounterclock-wise.

(4) TS-2500A/ARM-92only.

(a) AC voltagesread for eachsetting of testset BEARINGswitch.

Performance standard

300° should be indicatedon the OBS indicator.

The null indication onAN/USM-140 will notchange.

(a)

( b)

(c)

(d)

297 to 300° indicatedon the OBS indicator.

Indicator test setSYNCHRO METERdeflects to the right.

27 to 33° indicated onOBS indicator.

Indicator test setSYNCHRO METERdeflects to the left

Voltage within limitsset in test procedure,

d. Test Set COMPASS SIMULATOR andIndicator, RMI ID-250A/ARN Test.

CheckpointI


(1) VOR/LOC-GLIDESLOPE switch setto VOR/LOC,megacycle andkilocycle select-ors set to 108.00,and the power

The VOR/LOC DC, VOR/LOC AC, and GS DSlamps on the test setlight. The 26 VAC PWR,LOC PWR, 1.0 FREQSELECT (MC) lamps Aand D, 0.1 FREQ SE-

4-24 Change 2

TM 11-6625-820-45

switch set toPWR.

(2) Rotate the COM-PASS SIMULA-TOR.

(3) Set the COMPASSSIMULATORto N.

(4) Press, and then re-lease, the SERVOAMP TEST push-button switch.

LECT (MC) lamps Band E, and 0.1 FREQSELECT (MC) lamp Bon the aid box light. TheFLAG meter indicates250 microamperes ±15.The DEVIATION meterindicates 75 microam-peres ±5 to the right of0. The TO–FROM meterindicates 500 microam-peres ±25 to the left of0.

RMI card follows theCOMPASS SIMULA-TOR within 2°.

RMI needle number 1 in-dicates 180° ±1. RMIcard indicates 0° ±1.

The FLAG meter indicates0 with the SERVOAMP TEST pushbuttonswitch pressed, and 250microampere ±15 withthe SERVO AMP TESTpushbutton released.

Change 2 4-24.1

e. Glide-Slope Frequency Information Test.

Checkpo in t

(1)

(2)

(3)

(4)

(5)

(6)

. (7)

(8)

(9)

Power switch set toOFF. Megacycleand kilocycle selec-tors set to 108.00.Resistance betweenJ of P2 and P ofJ 4 .

Resistance betweenJ of P2 and Gof J4.

Resistance betweenJ of P2 and D ofJ 4 .

Resistance betweenJ of P2 and A ofJ 4 .

Megacycle and kilo-cycle selectorsset to 110.20. Re-sistance between Jof P2 and B of J4.

Resistance betweenJ of P2 and E ofJ 4 .

Resistance betweenJ of P2 and F ofJ4.

Resistance betweenJ of P2 and S ofJ 4 .

Megacycle and kilo-cycle selectors setto 110.40. Resist-ance between J ofP2 and R of J4.

P e r f o r m a n c e s t a n d a r d

0 ohm.

0 ohm.

0 ohm.

0 ohm.

0 ohm.

0 ohm.

0 ohm.

0 ohm.

TM 11-6625-820-45

f. Meter Movement Accuracy Tests.

Checkpo in t

( 1 ) T h e C O M M O N p o s tof TS–682A/GSM-1 connectedto b of P2, and the500 UA currentjack connected toa of P2. Output oft h e T S - 6 8 2 A /GSM-1 set to 500m i c r o a m p e r e .

( 2 ) T h e C O M M O N p o s to f T S - 6 8 2 A /GSM-1 connectedto Z of P2, andthe 1MA currentjack connected toY of P2. outputof the TS-682A/GSM–1 is set to 1milliampere.

( 3 ) T h e C O M M O N p o s to f T S - 6 8 2 A /GSM-1 connectedto m of P2, andthe 200 UA cur-rent pack connectedto n of P2. Outputof the TS-682A/GSM-1 set to 150microamperes.

( 4 ) T h e C O M M O N p o s to f T S - 6 8 2 A /GSM-1 connectedto n of P2 and the200 UA currentjack connected tom of P2. Output oft h e T S - 6 8 2 A /GSM-1 set to 150microamperes.

P e r f o r m a n c e s t a n d a r d

The FLAG meter indicates500 microamperes ±10.

The TO-FROM meter in-dicates 1,000 microarn-p e r e s ± 2 0 .

T h e D E V I A T I O N m e t e rindicates 150 micro-amperes ±3 to the leftof 0.

T h e D E V I A T I O N m e t e rindicates 150 microam-peres ±3 to the rightof 0.

4-25

0 o h m .

TM 11-6625-820-45

Figure 4-8. Color-code marking for MIL-STD resistors.

4-26

TM 11-6625-820-45

APPENDIX

REFERENCES

Following is a list of applicable references available to general support and depot main-tenance personnel of Test Set, Radio AN/ARM-92 and AN/ARM-92A.

TB Sig 355-1TB Sig 355–2

TB Sig 355-3

TM 11-2535BTM 11-5017TM 11-5826-211-50TM 11-5826–226-35

TM 11-6625–200–12

TM 11-6625-320-12

TM 11-6625-492-12

TM 11-6625-535-15

TM 11-6625–588–15

TM 11-6625-820-12

Depot Inspection Standard for Repaired Signal Equipment.Depot Inspection Standard for Refinishing Repaired Signal Equipment.Depot Inspection Standard for Moisture and Fungus Resistant Treat-

ment.Meter Test Set TS-682A/GSM-1.Output Meters TS-585A/U, TS-585B/U, TS-585C/U, and TS-585D/U.Depot Maintenance Manual: Radio Magnetic Indicator ID-250A/ARN.Direct Support, General Support, and Depot Maintenance Manual:

Radio Receiving Sets AN/ARN-82 and AN/ARN-82A.Operator and Organizational Maintenance Manual: Multimeters

ME-26A/U, ME-26B/U, and ME-26C/U.

Organizational Maintenanceand Voltmeters, Electronic

Operator and OrganizationalAN/ASM-101.

Organizational, DS, GS, andAN/USM-140A.

Organizational, DS, GS, and

Manual: Voltmeter, Meter ME-30A/UME-30B/U, ME-30C/U, and ME-30E/U.Maintenance Manual: Test Set, Resolver

Depot Maintenance Manual: Oscilloscope

Depot Maintenance Manual: ModulatorMD–83A/ARN, Including Repair Parts and Special Tool Lists.

Organizational Maintenance Manual: Test Set, Radio AN/ARM–92and AN/ARM-92A.

Change 2 A-1

C 1, TM 11-6625-820-45

APPENDIX B

DIRECT SUPPORT, GENERAL SUPPORT, AND.

DEPOT REPAIR PARTS

Section I. INTRODUCTION

B-1. General

This appendix l is ts the quanti t ies of repairparts, Section II, for general support and de-pot maintenance and is a basis for requisition-ing authorized parts . I t is a lso a guide fordepot maintenance in establishing initial cate-gories of spare parts.

Note. No special tools , test , and support equipmentare required.

B-2. Explanation of Columns

An explanation of the columns is given below.a. Sequence Number Column. This column

is for sequential line item control, commencingwith the first line item on the first page ofthe list, and continuing numerically to the lastitem on the page of the list.

b. For Authorized Allowance See SequenceN u m b e r C o l u m n . This column lists the nu-

merical sequence number for items that havemore than one occurrence throughout the listand refers to the first occurrence for author-ized allowances.

c. Source, Maintenance, and RecoverabilityCode Column. Source, maintenance, and re-coverability codes indicate the commodity com-mand responsible for supply, the maintenancecategory at which an item is stocked, catego-ries at which an item is installed or repaired,and whether an item is repairable or salvage-able. The source code column is divided intofour parts.

(1) Column A. This column indicates themateriel code and designates the area of re-sponsiblity for supply. AR 310-1 defines the

basic numbers used to ident i fy the mater ielcode. If the part is electronic materiel respon-sibility, the column is left blank.

(2) Column B. This column indicates thepoint within the maintenance system wherethe part is available. Source codes and theirexplanations are as follows:

E x p l a n a t i o n

P — Applies to repair parts that are stocked inor supplied from the GSA/DSA, or Armysupply system, and authorized for use atindicated maintenance categories.

X1 — A p p l i e s t o r e p a i r p a r t s t h a t a r e n o t p r o -c u r e d o r s t o c k e d , t h e r e q u i r e m e n t f o rwhich will be supplied by the use of nexthigher assembly or component .

X2 — Applies to repair parts that are not stocked.T h e i n d i c a t e d m a i n t e n a n c e c a t e g o r y r e -quiring such repair parts wil l at tempt too b t a i n t h e m t h r o u g h c a n n i b a l i z a t i o n ; i fn o t o b t a i n a b l e t h r o u g h c a n n i b a l i z a t i o n ,such r epa i r pa r t s w i l l be r equ i s i t i onedw i t h suppor t ing ju s t i f i ca t ion throughnormal supply channels.

N o t e . " A H " a n d " M D " a p p l i e s t o p a r t s t h a trequire manufacture or assembly at a category higherthan that authorized for instal lat ion wil l indicate inthe source code column the higher category.

(3) Column C. This column indicates thelowest maintenance category authorized to in-stall the part.

O Organizational MaintenanceH General Support Maintenance

(4) Column D. The symbol in this columnindicates whether the i tem is repairable orsalvageable. Recoverability code and its expla-nation is as follows:

B-1

Code

C o d e E x p l a n a t i o n

C 1, TM 11-6625-820-45

E x p l a n a t i o n

R — Applies to repair parts and assemblies thata r e economica l l y r epa i r ab l e a t DSU andG S U a c t i v i t i e s a n d n o r m a l l y a r e f u r n -ished on an exchange basis.

d. Federal Stock Number Column. This col-umn lists the 11-digit Federal stock number.

e. Indent Code Column. This column indi-cates the breakdown of each given part or as-sembly. Components, assemblies, and subas-semblies are listed in top-down order. That is,the assemblies which are part of a componentare listed immediately below that component,and the subassemblies which are part of anassembly are listed immediately below that as-sembly.

f . Descript ion Column. The Fede ra l i t emname, a five-digit manufacturer’s code, and apar t number are included in this column.

g. Unit of Issue Column. The unit of issueis the supply term by which the individualitem is counted for procurement, storage, req-uisitioning, allowances, and issue purposes.

h. Expendabil i ty Column. N o n e x p e n d a b l eitems are indicated by NX. Expendable itemsare not annotated.

i. Quantity in Use Column. This column liststhe quanti ty of each part found in a givenassembly or component. "A/R" indicates thatthe item may be requisitioned “as required”;however, est imated minimum quanti t ies maybe stocked to cover immediate needs.

j . Quanti ty Per Equipment Column. T h i scolumn lists the total quantity of each part,assembly, or component required for use inthe overall equipment. Subsequent appearancesof the same item in the same assembly are in-dicated by the letters “REF”. “A/R” indicatesthat the i tem may be requisi t ioned "as re-quired"; however, estimated minimum quanti-ties may be stocked to cover immediate needs.

k. Direct Support Column. No parts author-ized for stockage at this category.

l. General Support Column. This column in-dicates quanti t ies of repair parts authorizedfor initial stockage for use in general supportmaintenance. The quantities are based on 100equipments to be maintained for a 15-dayperiod.

m. Depot Column. The numbers in this col-umn indicate quanti t ies of repair parts au-

B-2

thorized for depot maintenance and for initialstockage for maintenance, and for supply sup-port to lower categories. The entries are basedon the quantity required for rebuild of 100equipments.

n. Illustrations Column.(1) Figure number. This column lists the

figure number used for the identification ofthe items in the illustration or text of the tech-nical manual.

(2) I tem Number. This column lists theitem number used for the identification of theitems in the illustration or text of the techni-a l manua l .

(3) Reference symbol . This column liststhe reference symbols used for the identifica-tion of the items in the illustration or text ofthe technical manual.

B-3. Parts for Maintenance

When this equipment is used for e lectronicservice organizat ions organic to theheadquarters or communication zonesvide theater communicat ions, thoseparts authorized up to and includingsupport are authorized for s tockageorganization operating this equipment

B-4. Requisitioning Information

a. The allowance factors are basedequipments. In order to determine the

theaterto pro-r epa i r

generalb y t h e

on 100number

of parts authorized for initial stockage for thespecific number of equipments supported, thefol lowing formula wil l be used and carr iedout to two decimal places.

Specific number of equipments supportedallowance factor

x =100

Number of par ts authorized for ini t ia ldockage.

b. Fract ional values obtained from abovecomputation will be rounded to whole numbersas follows :

(1) When the total number of parts au-thorized is less than 0.5, the quantity author-ized will be zero.

(2) When the total number of parts au-thorized is between 0.5 and 1.0, the quantityauthorized will be one.

Code

(3) For all values above one, fractionalvalues below 0.5 will revert to the next lowerwhole number and fract ional value 0.5 andabove will advance to the next higher wholenumber.

c. The quantities determined in accordancewith the above computation represent the ini-tial stockage for a 15-day period.

B-5. Location of Repair Parts

Follow the procedures given in a through cbelow.

C 1, TM 11-6625-820-45

a. Use the table of contents to locate the ap-propriate appendix of the repair parts list.

b. If the figure number, item number and/

or reference designation is available, locate the

item by scrutiny of columns 14, 15, and/or 16

of the repair parts list.

c. If the figure number, item number and/

or reference designation is not known, check

the description column (column 6) in the re-

pair parts list to locate the part.

B - 3

B-2

4

B-2

7

B-2

9

TM 11-6625-820-45

INDEX

Alignment:Compass simulator_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _General _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _

OBS indicator _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Precision bearing _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ RMI _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Test equipment required _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Compass simulator:Alignment _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Detailed functioning_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _General support and depot testing _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Control unit, schematic diagram, fig. 4-1:Physical tests and inspection _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Test _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Troubleshooting procedure _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Depot overhaul standards _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Fabricated cable, construction details _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Functioning, detailed:

Aid box _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Compass simulator _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Resolver transmitter _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Current measuring circuits _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Phase shifting _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Power distribution circuits _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _RMI _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Functioning, general, Test Set, Radio AN/ARM-92 _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _Functioning, general, Test Set, Radio AN/ARM-92A _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _General support and depot testing:

Aid box physical tests and inspection _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Aid box tests _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Documents

TM 11-6625-820-45 · AMP TEST pushbutton switch S4 is pressed, it connects 27.5 volts dc to the RMI servoam-plifier and to flag meter relay K2. The flag meter relay energizes and