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TM 11-6625-2751-14&P

TECHNICAL MANUAL

OPERATOR’S, ORGANIZATIONAL,

DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL

INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS

FOR

OSCILLOGRAPH RECORDER RO-460(V)1/U

(HEWLETT-PACKARD MODEL 7702B)

(NSN 6625-00-464-2957)

HEADQUARTERS, DEPARTMENT OF THE ARMY

MAY 1979

This manual contains copyright material reproduced by permission of the Hewlett-Packard Company.

TM 11-6625-2751-14&P

TECHNICAL MANUAL HEADQUARTERS

No. 11-6625-2751-14&P WASHINGTON, DC,

OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, AND GENERAL SUPPORT

You can improve this manual by recommending improvements using DA Form 2028-2 located in the back of the manual. Simply tear out the self-addressed form, fill it out as shown on the sample, fold it where shown, and drop it in the mail.

If there are no blank DA Forms 2028-2 in the back of your manual, use the standard DA Form 2028 (Recommended Changes to Publications and Blank Forms) and forward to the Commander, US Army Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME-MQ, Fort Monmouth, NJ 07703.

In either case a reply will be furnished direct to you.

}

MAINTENANCE MANUAL INCLUDING

REPAIR PARTS AND SPECIAL TOOLS LISTS

FOR

OSCILLOGRAPH RECORDER RO-460(V)1/U

(HEWLETT-PACKARD MODEL 7702B)

(NSN 6625-00-464-2957)

REPORTING OF ERRORS

DEPARTMENT OF THE ARMY

11 May 1979

This manual is an authentication of the manufacturer’s commercial literature which, through usage, has been found to cover the data required to operate and maintain this equipment. Since the manual was not prepared in accordance with military specifications , the format has not been structured to consider levels of maintenance.

Model 7702A TM 11-6625-2751-14&P

TABLE OF CONTENTS

Section Page O INTRODUCTION 0-1 Section Page

I. GENERAL INFORMATION .......................1-1 IV. PRINCIPLES OF OPERATION............................ 4-1

1-1. Description ......................................1-1 4-1. Introduction.............................................. 4-1

1-6. Component Identification ...........1-1 4-3. Basic Circuits........................................... 4-1

1-8. Standard System Options..........1-1 4-4. Diodes................................................ 4-1

1-10. Special Options .........................1-1 4-9. Transistors ......................................... 4-1

1-12. Component Description ..................1-1 4-12. Component Circuit Description ................ 4-3

1-13. Model 7702-OlA Recorder.........1-1 4-13. Preamplifiers. ..................................... 4-3

1-16. Model 7700-02A Driver.............. 4-16. Driver Amplifier................................... 4-3

Amplifier.....................................1-3 4-26. System Power Supply ....................... 4-5

1-18. Preamplifiers, 8800 Series.........1-3 4-33. Recorder Description .............................. 4-9

1-20. Model 1069-02A Mobile Cart.....1-3 4-35. Chart Drive Components.................... 4-9

1-22. System Specifications................1-3 4-37. Drive Motor and Speed

............................................... Reduction Gears ................................4-9

II. INSTALLATION..........................................2-1 4-40. Push-button Actuated Clutch

2-1. Introduction .....................................2-1 Assemblies ..................................... 4-11

2-3. Initial Inspection .............................2-1 4-44. Chart Drive Circuits.................................. 4-11

2-4. Mechanical Inspection ...............2-1 4-47. Stylus Heat Circuits ................................. 4-12

2-6. Electrical Check ........................2-1 4-51. Marker and Timer Circuit ......................... 4-13

2-8. Claims and Repackaging ................2-1

2-9. Claims for Damage ....................2-1 V. MAINTENANCE ................................................... 5-1

2-11. Repacking for Shipment ............ 5-1. Introduction ............................................. 5-1

or Storage ..............................2-1 5-3. Test Equipment ....................................... 5-1

2-13. Installation.......................................2-1 5-5. Performance Checks .............................. 5-1

2-15. Environment...............................2-1 5-6. General .............................................. 5-1

2-19. Rack Mounting Instructions........2-1 5-8. Variable Line Voltage............................... 5-1

2-21. System in Portable Case ...........2-1 5-10. Preventive Maintenance .......................... 5-9

2-23. AC Power Requirements ...........2-1 5-12. Mechanical......................................... 5-9

2-26. Input Signal Connections...........2-2 5-16. Electrical ............................................ 5-10

2-28. Signal Input Connectors ............2-2 5-18. Cleaning ............................................. 5-10

2-30. Signal Input Cable .....................2-2 5-20. Lubrication ......................................... 5-10

2-33. Input Connector Wiring for......... 5-23. Brake and Drive Roll

Non-Guarded Preamplifiers .......2-3 Maintenance Procedures ................... 5-10

2-35. Input Connector Wiring for .............. 5-24. Brake Roll Lubrication........................ 5-10

Guarded Preamplifiers...............2-3 5-25. Brake Roll Adjustment........................ 5-11

2-37. 8805A Carrier Preamplifier.............. 5-29. Drive Roll Replacement...................... 5-12

Input Cables...............................2-4 5-36. Paper Take-Up Maintenance

2-39. Cable Assembly for use with........... Procedures ........................................5-14

Sanborn Transducers ................2-4 5-37. Paper Take-Up Adjustment ................ 5-14

2-41. Instructions for Assembling ............. 5-38. Paper Take-Up Assembly

Signal Input and Reference ....... Lubrication ..................................... 5-14

Cables........................................2-4 5-41. Stylus Adjustments and Repairs.............. 5-15

2-43. 8806A Phase Sensitive Demod- ..... 5-42. Stylus Pressure ................................. 5-15

ulator Signal Cables ..................2-4 5-44. Stylus Mechanical Stop...................... 5-16

2-47. Signal Monitor Connections ...........2-5 5-46. Stylus Mechanical Center

2-49. Remote Recorder Operation ...........2-5 (Zero).............................................. 5-16

2-51. Remote Chart Drive................... 5-48. Corrective Maintenance........................... 5-16

START-STOP control.............2-5 5-49. Disassembly of System

2-54. Remote Marker Control..............2-5 Components ................................... 5-16

2-57. Auxiliary Marker Operation.........2-5 5-56. Disassembly and Lubrication of

2-59. Initial System Check .......................2-5 Chart Drive Components.................... 5-17

2-63. To Check Recorder Drive .......... 5-59. Chart Drive Lubricants........................ 5-17

Functions................................2-5 5-61. Shaft Disassembly and

2-64. To Check Recorder Marker............. Lubrication .....................................5-18

and Timer Functions .................2-5 5-63. Shaft A Servicing ............................... 5-18

............................................... 5-64. Shaft B Servicing ............................... 5-18

III. OPERATION..............................................3-1 5-66. Shaft C Servicing ............................... 5-18

3-1. Introduction .....................................3-1 5-67. Shaft D Servicing ............................... 5-18

3-3. Controls and Connectors.................3-1 5-69. Shaft E Servicing 5-20

3-5. Operating Procedures ....................3-1 5-70. Shaft F Servicing .................................... 5-20

TM 11-6625-2751-14&P

Model 7702A

TABLE OF CONTENTS (Cont.)

Section ..................................................Page Section ...................................................Page

V. MAINTENANCE (Cont.) ............................. V. MAINTENANCE (Cont.)

5-72. Drive Motor Sprocket and................. 5-85. Troubleshooting ................................5-24

Chain Lubrication ........................5-20 5-87. Electrical Performance Check............5-24

5-73. Gear Lubrication ..............................5-20 5-89. Mechanical Problems.........................5-24

5-75. Results of Incorrect Lubrica-............. 5-92. Etched Circuit Board Repair...............5-24

tion Procedure ............................. 5-20 5-95. Component Replacement..................5-24

5-77. Galvanometer Assembly .................5-20 VI. UPDATING SUPPLIES. ................................6-1

5-80. Galvanometer Magnet

Replacement.............................5-20 VII. MANUAL CHANGES.....................................7-1

5-82. Galvanometer Insert

Replacement................................5-20

LIST OF ILLUSTRATIONS

Figure ..................................................Page Figure ...................................................Page

1-1. Model 7702A Recording System and......... 4-9. Unregulated ± 18 V Supply ..........................4-6

Option 01 ..........................................1-0 4-10. Unregulated ± 18 V Power Distribution..........4-7

1-2. Model 7702-0lA Recorder ..........................1-2 4-11. Regulated ± 12 V Supply...............................4-7

1-3. Model 7700-02A Driver Amplifier................1-2 4-12. Regulated ± 12 V Power Distribution.............4-8

1-4. 8800 Series Preamplifier (8801Ashown)....1-2 4-13. 440 Hz Plug-In Oscillator Block Diagram

1-5. Model 1069-02A Mobile Cart .....................1-3 With Associated Circuits ...............................4-8

1-6. 7702A System Power Supply. ...................1-3 4-14. 2400 Hz Plug-In Oscillator Block

.................................................. Diagram ...................................................4-9

2-1. Slide Kit - 01060-60310 .............................2-2 4-15. Chart Drive Motor and Speed

2-2. Portable Case ............................................2-2 Reduction Gears............................................4-10

2-3. 10G3-34FW Connector ..............................2-2 4-16. First Speed Reduction Assembly

2-4. Cable Preparation.......................................2-3 Operation ...................................................4-11

2-5. Input Connector Wiring, Non-Guarded.......2-3 4-17. Chart Drive Circuit ........................................4-12

2-6. Input Connector Wiring, Guarded. .............2-4 4-18. Stylus Heat Control Circuit ............................4-13

2-7. Y-Cable Sanborn No. 5060-4602 ...............2-4 4-19. Marker and Timer Control Circuitry ...............4-14

2-8. Remote Run Circuit Diagram .....................2-5

2-9. Remote Marker Circuit Diagram.................2-5 5-1. Recorder Platen Writing Edge.......................5-8

2-10. System Controls.........................................2-6 5-2. Stylus Adjustment Screws and Limits............5-9

.................................................. 5-3. Brake Roll Adjusting Screw Location.............5-11

3-1. Typical 2-Channel Recording ....................3-1 5-4. Brake Roll Removal.......................................5-11

3-2. Front Panel Controls ..................................3-2 5-5. Bearing Retainer and Gears .........................5-12

3-3. Rear Panel Controls .................................3-3 5-6. Paper Table Removal....................................5-13

3-4. Permapaper Loading Procedures ..............3-4 5-7. Paper Take-Up Adjustment...........................5-14

3-5. System Operating Procedures .................3-6 5-8. Calibrating and Measuring Stylus

3-6. Remote System Operation .........................3-7 Pressure ............................................5-15

.................................................. 5-9. Stylus Pressure Adjustment ..........................5-16

.................................................. 5-10. Heated Stylus Part No. 398............................5-17

4-1. Model 7702A System Block Diagram.........4-1 5-11. Chart Drive Shafts .......................................5-19

4-2. Basic Diode Circuits ..................................4-2 5-12. Shaft A Lubrication Procedures..................... 5-21

4-3. Transistor Operation ................................4-2 5-13. Clutch Sleeve Clearance...............................5-23

4-4. Signal Distribution Diagram .......................4-4 5-14. Shaft C Inspection.........................................5-23

4-5. Model 7700-02A Driver Amplifier................ 5-15. Excessive Wear in Clutch Assembly.............5-23

Block Diagram .................................4-4 5-16. Checking Galvanometer Sensitivity...............5-24

4-6. Feedback Circuit - Simplified Schematic....4-5 5-17. (a) Troubleshooting Chart

4-7. Galvanometer Frequency Response and... Problems in One Channel ............................5-27

Transient Response..........................4-5 (b) Troubleshooting Chart

4-8. 7702A System Frequency Response .......4-6 Problems in Both Channels ....................................5-28

iii

TM 11-6625-2751-14&P

Model 7702A

LIST OF ILLUSTRATIONS (Cont.)

Illustrated Parts Breakdown

Figure ..................................................Page Figure ...................................................Page

1. Two-Channel Thermal Recording Sub-...... 13. Power Supply Assembly, Top View

System (Model 7702A) ................... 5 (07702-60030) ...................................27

2. Two-Channel Thermal Recorder................ 14. Power Supply Assembly, Bottom View

115/230V, 60Hz (Model 7702-01A).. 7 (07702-60030)....................................29

3. Driver Amplifier Assembly.......................... 15. Regulator Card and Bracket Assembly

(Model 7700-02A) ............................ 9 (868-500A-C6)...................................31

4. Printed Circuit Board Assembly.................. 16. Diode Board Assembly (07702-60070).........33

(07700-62010)............................................11 17. Oscillator Card Assembly, 2400 Hz

5. Amplifier Housing Assembly ....................13 (868-500A-C13).................................35

6. Galvanometer Assembly Complete............ 18. Oscillator Card Assembly, 440 Hz

(320-200-Cl0)....................................15 (868-500A-C14)............................37

7. Front Panel, Door and Paper Take-Up....... 19. Timer Assembly (14002S - 14002T -

Assembly (07702-60220) .......................... 17 14002R- 14002V)...............................39

8. Ten-Button Push Switch (3101-1001)........19 20. MM/Min Drive Motor Kit - 60:1

9. Paper Drive Assembly (table, brake........... (07702-60110) (07702-60220)...........39

and associated parts)....................... 21 21. Mobile Cart (1069-02A) ...............................41

10. Paper Drive Assembly (gear train and........ 22. Portable Case (7702-14A).............................43

associated parts) ..................................... 23 23A.7702-01A Recorder Schematic.....................47

11. Table, Drive Roll and Brake Assembly....... 25 23B.Model 7702A Power Supply Plug-In

12. Clutch Actuator Assembly (07702-60100).. 25 Assemblies, Schematic Diagram.......49

LIST OF TABLES

Table ..................................................Page Table ...................................................Page

1-1. Model 7702-01lA Specifications ................1-4 5-1.Recommended Test Equipment ...................5-1

1-2. Model 7700-02A Specifications .................1-5 5-2.Performance Checks ....................................5-2

1-3. 8800 Series Preamplifiers .........................1-5 5-3.Recorder Minor Repairs and

1-4. System Specifications................................1-6 Adjustments...................................................5-5

1-5. System Accessories...................................1-7 5-4.Timing Calibration..........................................5-12

.................................................. 5-5.Lubricants....................................................5-17

4-1. Speed Reduction Ratios ............................4-11

4-2. Timer Assembly Part Numbers ................4-15

APPENDIXES

A. ILLUSTRATED PARTS BREAKDOWN.........................................................................................................A-1

B. REFERENCES ...............................................................................................................................................B-1

C. COMPONENTS OF END ITEM LIST (not applicable) D. ADDITIONAL AUTHDRIZATION LIST (not applicable)

E. MAINTENANCE ALIOCATION ......................................................................................................................E-1

F. EXPENDABLE SUPPLIES AND MATERIALS LIST (not applicable) G. REPAIR PARTS AND SPECIAL TOOLS LISTS (PART NUMBER - NATIONAL STOCK

NUMBER CROSS REFERENCE INDEX) ...............................................................................................G-1

Model 7702A

TM 11-6625-2751-14&P

Figure 1-1. Model 7702A Recording System and Option 01

0-0

SECTION O.

INTRODUCTION

0-1. SCOPE.

This manual describes Oscillograph Recorder RO460(V)1/U and provides instructions for operation and maintenance. Throughout this manual, the RO-460(V) 1/U is referred to as Hewlett-Packard Model 7702B. Refer to Section VI for differences between the 7702A and 7702B.

0-2. INDEXES OF PUBLICATIONS.

a. DA Pam 310-4. Refer to the latest issue of DA Pam 310-4 to determine whether there are new editions, changes, or additional publications pertaining to the equipment.

b. DA Pam 310-7. Refer to DA Pam 310-7 to determine whether there are modification work orders (MWO’s) pertaining to the equipment.

0-3. FORMS AND RECORDS.

a. Reports of Maintenance and Unsatisfactory Equipment. Maintenance forms, records, and reports which are to be used by maintenance personnel at all maintenance levels are listed in and prescribed by TM 38-750.

b. Report of Packaging and Handling Deficiencies. Fill out and forward DD Form 6 (Pack aging Improvement Report) as prescribed in AR 70058/NAVSUPINST 4030.29/AFR 71-13/MCO P4030.29A and DSAR 4145.8.

TM 11-6625-2751-14&P

c. Discrepancy in Shipment Report (DISREP) (SF 361). Fill out and forward Discrepancy in Shipment Report (DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33B/AFR 75-18/MCO P4610.19C and DLAR 4500.15.

0-4. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR).

EIR’s will be prepared using Standard Form SF 368, Quality Deficiency Report. Instructions for preparing EIR’s are provided in TM 38-750, The Army Maintenance Management System. EIR’s should be mailed direct to Commander, US Army Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME-MQ, Fort Monmouth, NJ 07703. A reply will be furnished directly to you.

0-5. ADMINISTRATIVE STORAGE.

Administrative storage of equipm ent issued to and used by Army activities shall be in accordance with paragr aph 2-11.

0-6. DESTRUCTION OF ARMY ELECRONICS MATERIEL.

Destruction of Army electronics materiel to prevent enemy use shall be in accordance with TM 750-244-2.

0-1

SECTION I.

GENERAL INFORMATION

1-1. DESCRIPTION.

1-2. The Sanborn Model 7702A is a two-channel thermal writing recording system, mounted in a mobile cart, that has excellent versatility through the use of all solid-state 8800 Series interchangeable pre- amplifiers. Any two of the 8800 Preamplifiers (see Table 1-3) may be used with the Model 7702A, permitting a broad range of measurements. ’Possible applications include high sensitivity AC and DC measurements, carrier excited transducer monitoring, rec ording of phase and amplitude in servo systems, and obtaining permanent records of AC levels having a wide dynamic range directly in dB on a linear scale. Complete operating and service instructions for eac h of the 8800 Ser ies Pream plif iers are contained in separate manuals.

TM 11-6625-2751-14&P

e. Option 11: Eight-speed recorder for 60 Hz power line. (Adds four mm/min recorder speeds by means of a 60:1 speed reduction.) f. Option 12: Eight-speed recorder for 50 Hz power line. (Adds four mm/min recorder speeds by means of a 60:1 speed reduction.) g. Option 13: One minute timer for 60 Hz power line. Provides one per minute timing marks on chart. For use with Option 11. h. Option 14: One minute timer for 50 Hz power line. Provides one per minute timing marks on chart. Used with Option 12. i. Option 15: Auxiliary marker. Records between channels 1 and 2 on chart paper; actuated by external contact closure. 1-10. Special Options.

1-3. The 7702A is also available in a portable carrying case with a protective cover over the front panel, or the recorder may be rack mounted.

1-4. Input signals to the 7702A System are connected to the signal input panel located on the rear of the recorder. The input connector contains a guard shield for high common-mode rejection. Output signals are available at the signal panel for connection to an oscilloscope or magnetic recorder.

1-5. Four chart speeds for industrial or medical applications are selected by front panel pushbuttons. Eight chart speeds, pushbutton selected, are optional. The recorder start-stop func tion is controlled either from the front panel or from a remote location.

1-6. Component Identification. 1-7. This Sanborn System consists of the following

major components: a. Model 7702-OlA Recorder Assembly, including power supply for preamplifiers and driver amplifiers. b. Model 7700-02A Driver Amplifiers (2). c. Model 1069A-02A Mobile Cart. d. 8800 Series Preamplifiers, as ordered. 1-8. Standard System Options.

1-9. The basic System, Model 7702A, is available with the following standard system options: a. Option 01: 7702A System less mobile cart. Slide kit 01060-60310 is included for rack mounting. b. Option 02: The 7702A System less mobile cart, mounted in portable case. c. Option 08: For 50 Hz power line. d. Option 10: Recorder with medical speeds (2. 5, 5, 25, and 50 mm/sec).

1-11. When contractual requirements require special modifications to the standard Sanborn 7702A System, complete data on the difference between the modified and standard system is covered in Section VII of this manual. The contents of this manual apply directly to instruments with Production Change Order (PCO) numbers up to 17-15637. Refer to Section VII for other PCO numbers 1-12. COMPONENT DESCRIPTION. 1-13. Model 7702-01A Recorder.

1-14. The 7702-0lA (Figure 1-2 shown with preamp lifiers installed) is a two-channel, four or eight-speed thermal writing recorder, with provisions f or m ounting two 8800 Series Preamplifiers. The recorder is mounted horizontally in the 7702A Mobile Cart, or vertically in the portable case or rack mount. The paper take-up assembly located on the left end of the recorder stores the chart paper on a take-up spool that is easily removed. Recorder charac teristics are given in Table 1-

1. 1-15. The power supply (Figure 1-6) provides oper-

ating power for the 7702-OlA Recorder, 8800 Series Preamplifiers, and two 7700-02A Driver Amplifiers. The mm/sec timer assembly 14002S and the optional mm/min timer assembly 14002R plug into the power supply. Also mounted on the rear of the power supply are three plug-in circuit boards; (1) Regulator Card 868500A-C6 which furnishes regulated +12 and -12 volts to the preamplifiers, (2) Oscillator Plug-in 868-500A-C13 which provides a 2400 Hz transducer excitation voltage for use with the 8805A Carrier Pre- amplifier, and (3) Oscillator Plug-in 868-500A-C14 which provides a 440 Hz chopper excitation voltage for Model 8803A High Gain Preamplifier.

1-1

TM 11-6625-2751-14&P

Figure 1-2. Model 77-01A Recorder

Figure 1-3. Model 7700-02A Driver Amplifier Figure 1-4. 8800 Series Preamplifier (8801A Shown)

1-2

1-16. Model 7700-02A Driver Amplifier. 1-17. One plug-in driver amplifier (Figure 1-3) is

provided for each recording galvanometer. The combination of driver amplifier and galvanometer simulate the characteristics of a galvanometer at 71% of critical damping, by negative velocity-voltage feed- back from the galvanometer in conjunction with a compensation circuit in the driver amplifier. Driver Amplifier specifications are listed in Table 1-2. 1-18.

Preamplifiers, 8800 Series. 1-19. Any of the solid-state high performance preamplifiers (Figure 1-4) for medical or industrial applications may be installed in the recorder. Preamplifiers may be interchanged easily from the front panel of the recorder by removing two panel mounting screws. Preamplif iers c ontain built-in voltage cali- br ation sources. 1-20. Model 1069-02A Mobile Cart.

1-21. The ruggedly constructed all-metal mobile cart (Figure 1-5) is an ideal unit for many recording applications. Metal bar handles mounted on both ends of the cart and large diameter rubber wheels permit the system to be moved from one location to another with minimum effort. The line power cord, which is permanently attached to the cart, is conveniently stored behind the rear panel. Two AC accessory out- lets are provided on the rear panel. A 5" high panel located on the top of the cart and two 7" panels loc ate on the front of the cart may be used to m ount signal panels or other instrumentation. 1-22. System Specifications.

TM 11-6625-2751-14&P

Figure 1-5. Model 1069-02A Mobile Cart

1-23. The power, weight and dimensions for the Model 7702A are listed in Table 1-4. 1-24. Accessories provided with the System (or available on order) are listed in Table 1-5.

Figure 1-6. 7702A System Power Supply

1-3

TM 11-6625-2751-14&P

Table 1-1. Model 7702-01A Specifications

RECORDER CHART SPEEDS:1, 5, 20, and 100 mm/sec are standard; four additional s peeds : 1, 5, 20, 100, mm/min, available

as Option 11 (eight speeds total). Medical speeds of 2. 5, 5, 25, and 50 mm/ sec available instead of standard speeds as Option 10. Options 10 and 11 may be combined for a total of eight medical speeds. Non-standard speeds available on special order. Speed regulation 1% at specified power line frequency.

CHART PAPER: 2-channel Permapaper( Sanborn No. 651-52. Paper width 5" (127 mm). Each recording channel 50 mm wide, with amplitude lines spaced 1 mm apart. Timing lines also have 1 mm spacing.

STYLUS: Stylus heat electrically controlled by speed selector and also adjustable by front panel control. Analog Stylus, Sanborn No. 398; Marker/Timer Stylus, Sanborn No. 411-10.

STYLUS HYSTERISIS: Recording affected by previous signals by less than 0O. 1 divisions. DAMPING:

Galvanometer with velocity-voltage feedback in combination with drive circuit simulates a 71% critically damped galvanometer.

MARKER: Marker on right side (lower edge) of chart is standard; center margin marker optional; amplitude of marker approximately 1. 5 mm. Marker is operated by front panel switch or by external contact closure.

TIMER: With TIMER pushbutton depressed, marker pulse occurs on right side of chart every second (standard) or every minute (see standard option, Paragraph 1-8). Marker operation over-rides timer signal.

COOLING: Mounting case vented top and bottom for convection cooling. For rack mounting, temperature inside rack should not exceed 40’C.

TERMINALS: Signal input, signal monitor, remote chart drive start-stop, and servo reference input located on rear.

FRONT PANEL CONTROLS: Individual STYLUS heat adjustments; individual galvanometer DAMPING screwdriver adjust; pushbutton TIMER, MARK and POWER switches; pushbutton SPEED selector switches.

POWER SUPPLY OUTPUT:

Regulated +12 volts at 500 milliamperes maximum, each polarity.

Unregulated ±18 volts at 1/2 ampere maximum, each polarity, less ±12V load current.

Regulation of ±12 volt output a) with 20% change in line voltage 1/o maximum.

b) with change in load, 0 to full load 2% maximum.

c) with change in temperature 3 mV/C' maximum. Ripple on ±12 V output at full load 10 millivolts maximum, peak-to-peak. Dynamic output impedance of +12V output: 1/2 ohm, DC to 10 kHz.

OSCILLATORS:

440 Hz Oscillator, 868-500-C14: Frequency Stability: 440 Hz ± 5% maximum. Output: Floating at 14 volts peak-to-peak at 1/2 watt. Amplitude stability +2% of constant load. 2400 Hz Oscillator, 868-500A-C13: Frequency Stability: 2400 Hz + 2% maximum. Output: 10 volts rms ±5% at 50 milliwatts maximum. Grounded center tap.

1-4

TM 11-6625-2751-14&P

Table 1-2. Model 7700-02A Specifications DRIVER AMPLIFIER FREQUENCY RESPONSE: DC to less than 3 dB down at 125 Hz for chart deflection of 10 divisions pp.

Damping set for 4% overshoot with a 10 division pp square wave.

SENSITIVITY: ±2. 5 volts nominal for full recording chart width deflection. NOISE: Less than 0. 1 division pp with zero signal input. RESPONSE TIME: Less than 5 msec, 10% to 90% for a 10 division square wave with damping set for 4%

overshoot.

DRIVER INPUT IMPEDANCE: (preamplifier output loading) 5K ohms, ±5%, single-ended, with signal

ground isolated from chassis ground.

LINEARITY:

Method 1: After setting mechanical zero of stylus within 0o. 1 division of chart center and calibrating for zero error at center scale and +20 divisions, error is less then ±0. 25 divisions at any point on printed coordinates.

Method 2: After setting mechanical zero of stylus within +1 division of chart center and calibrating for zero error at lower and upper ends of printed coordinates, error is less than t0. 5 division at any point on the scale.

GAIN STABILITY (after one hour warmup): Temperature: Less than 0. 25%/10'C, 20° to 40°C.

Line Voltage: 0. 5%, 103 to 127 volts.

ZERO DRIFT (driver amplifier input shorted and after one hour warmup): Temperature: Less then

0.25 div/10°C, 20° to 40°C. Line Voltage: 0.1 div, 103 to 127 volts. Paper Drift: Less than

0.25 div.

LIMITING: Electrical limiting in drive circuit at approximately 125% of full scale. Stylus is mechani-

cally limited by spring stops.

Table 1-3. 8800 Series Preamplifiers Preamplifier Description Sensitivity 8801A Low Gain DC Preamplifier 5 mV/div

8802A Medium Gain DC Preamplifier 1 mV/div 8803A High Gain DC Preamplifier 1 µV/div 8805A Carrier Preamplifier (with calibrated CAL factor) 10 µV/div 8806B Phase Sensitive Demodulator 0. 5 mV rms/div 8807A AC-DC Converter 1 mV rms/div (at x20

scale expansion) 8808A Log-Level Preamplifier 100 µV rms 8809A Special Purpose DC 20 mV/div

NOTE: All preamplifiers except 8806B and 8808A feature calibrated zero suppression.

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Table 1-4. System Specifications

POWER: 115/230 volts ± 10%, 60Hz, approximately 200 watts. 115/230 volts ±10%, a50 Hz, specify Option 08. WEIGHT: 130 lb. (59kg), includes 1069-02A Mobile Cart and two preamplifiers. DIMENSIONS: (see illustrations below)

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Table 1-5. System Accessories Qty. Description Number 2 Signal Input Connector 10G3-34FW

2 Signal Output Connector 10B9-5MW 1 Remote Run Connector 10A5-3MW 1 Remote Run Connector Cable Clamp 10OA5-lFWA 1 Remote Marker Plug 10G2-22MW 1 Power Cord 3-wire 10G3-42MFW 1 Adapter, 3-wire to 2-wire 10G3-11MFW 2 Fuse 0.5 Amp Slo Blo (F2, F3) 26B-4 1 Fuse 0.8 Amp Slo Blo (Fl 220V) 26B-6 1 Screwdriver 37A-10A 2 Record Spool 94-104P1 1 Spline Wrench 100-600-C5 2 Galvanometer Stylus 398 1 Roll, Permapaper 651-52 1 Stylus Pressure Tester 14015A

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SECTION II.

INSTALLATION

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2-1. INTRODUCTION. 2-2. This section contains information on unpacking, inspection, repacking, and installation. 2-3. INITIAL INSPECTION. 2-4. Mechanical Inspection.

2-5. If external damage to the shipping carton is evident, ask the carrier’s agent to be present when the System is unpacked. Check the System for external damage such as broken controls or connectors, and dents or scratches on the panel surface. If damage is found, refer to Paragraph 2-8 for recommended claim procedure and repacking information. If the shipping carton is not damaged, check the cushioning material and note any signs of severe stress as an indication of rough handling in transit. Retain the packaging material for possible future use. 2-6. Electrical Check.

2-7. Check the electric al performance of the Sys- tem as soon as possible after rec eipt; see Section V for the recommended performance checks. The checks will verify that the System is operating within the specifications listed in Table 1-1. This check is a good test procedure for incom ing quality control inspection and for an operational check after repairs or adjustments have been made. 2-8. CLAIMS AND REPACKAGING. 2-9. Claims for Damage.

2-10. If physical damage is evident or if the System components do not meet specifications when received, notify the carrier and the nearest Hewlett-Packard Sales/Service Office (see list in back of manual). The Sales/Service Office will arrange for repair or replacement of the unit(s) without waiting for settlem ent of the claim against the carrier. 2-11. Repacking for Shipment or Storage. 2-12. If the instrument is to be shipped to a HewlettPackard Sales/Service Office, attach a tag showing owner and address, instrument model and serial number, and the repair required. The original ship- ping carton and packaging material, with the exc eption of accor dionpleated pads, may be reusable. The Hewlett-Packard Sales/Service Office will also pro- vide information and recommendations on materials to be used if the original packaging material is not available or not reusable. Materials should include, (1) a double-walled carton (check with a freight carrier for test s tr ength requir ed), ( 2) heavy paper or sheets of cardboard to protect all instrument surfaces ; use extra m aterial ar ound projec ting parts of the instrument, (3) at least four inches of tightlypacked shock-absorbing material surrounding the instrument. Close the package securely with heavy paper tape.

2-13. INSTALLATION. 2-14. The 7702A System is ready for use after removal from the packing case. No packing materials are contained in the recorder section. T he system is shipped without Permapaper mounted in the recorder; see paper loading instructions in Section III. 2-15. Environment. 2-16. System location should be reasonably free from vibration, dust, corrosive or explosive vapors or gases, extremes of tem perature, humidity, etc. The floor should be level and must supply support for all four wheels of the System. For a cabinet mounted installation, allow sufficient room at the f ront for operation with any part of the System extended forward, and at the rear for servicing with access door open. 2-17. The 7702A System requires no additional cooling. For rack mounting (7702A, Option 01), the tem per-

ature inside the rack cabinet should not exceed 40°C. 2-18. Check that the power line voltage, voltage regulation, power capacity, frequency, and frequency stability are suitable for the requirements of the Sys- tem. The time-axis accuracy of the recording will be directly dependent upon the frequency stability of the power line. 2-19. Rack Mounting Instructions.

2-20. Model 7702A, Option 01, consists of the Model 7702-0lA Recorder, with Slide Kit 01060-60310, for mounting in a cabinet. To install the recor der, attach the slides to the side rails of the c abinet. Figure 2-1 shows the location of the mounting holes for the slide kit. Slide the recorder into the side rails and fasten the recorder in place with panel screws. 2-21. System in Portable Case.

2-22. Model 7702A, Option 02, consists of the 7700OlA Recorder mounted in a portable transit case 770214A, shown in Figure 2-2. Two side handles are used f or carrying the case. A removable metal c over protects the recorder front panel when being transported. Signal input and power cables are connected to the s ystem through an open- ing in the rear of the case. 2-23. AC Power Requirements.

2-24. The Model 7702A may be operated from an ac source of 155 or 230 volts (+10%), 60 Hz. Model 7702A, Option 08, operates on 115 or 230 volts (+10%), 50 Hz. With the instr ument power cord disconnected, move the slide switch located on the rear panel (see Figure 3-3) until the desired voltage numbers (115 or 230) are visible. A narrow blade screwdriver may be used to operate the switch. Fuse F1 should be 1.5 amp slowblow for 115 volt operation, or 0.8 amp slow-blow for 230 volt operation.

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Figure 2-2. Portable Case

Figure 2-1. Slide Kit - 01060-60310

2-25. Three-Conductor Power Cable. To protect operating personnel, the National Electrical Manufacturers’ Association (NEMA) recommends that the instrument and cabinet be grounded. The Model 7702A is supplied with a three-conductor power cable which, when plugged into an appropriate receptacle, grounds the instrument to the power line ground. The round pin on the power cable is the ground c onnection. To retain this protection feature when operating the instrument from a two-contact outlet, use the 10G311lMFW three-conductor to two- conductor adapter (supplied as an accessory with the instrument) and connect the green wire to the outlet box.

2-26. Input Signal Connections. 2-27. The 8800 Preamplifier signal input circuits may

be divided into two types, guarded and non- guarded. Preamplifiers having a guard shield terminal (8803A, 8806B, 8807A) feature a high comm on- mode rejection ratio. To obtain the high rejection ratio, the signal input cable must contain a guard shield. Non-guarded preamplifiers (8801A, 8802A, 8805A, 8808A, 8809AY do not require a guard shield in the signal input cable. Additional information on input signal connections is contained in the preamplifier instruction manuals.

Figure 2-3. 10G3-34FW Connector

2-28. Signal Input Connectors. 2-29. Two signal input connectors, 10G3-34FW(see

Figure 2-3), are supplied as access ories with the system. The connectors plug into the signal input jac k s J 1 and J2 on the rear of the recorder. J1 signals (channel 1) are internally cabled to the left pre- amplifier (viewed from the front of the recorder) and r ecorded on the upper channel of the chart paper. J2 input signals are cabled to the right preamplifier, and are recorded on the lower channel of the chart paper.

2-30. Signal Input Cable. 2-31. Two conductor shielded cable 3/16" O.D., with

single or doubled braided shield is required for connecting the signal source to the input connectors. See Figure 2-4 for cable preparation information.

2-2

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NOTE

Single conductor cable can be used with the 8808A and 8809A Preamplifiers, which have single-ended input circuits. Connect the cable center conductor to pin A, and the shield to pin B.

Figure 2-6. Input Connector Wiring, Guarded

2-32. Preamplifiers which have a guard shield input terminal use double shielded cable for a fully guarded input circuit. The inner shield connects to the common mode potential of the signal source to reduce capacitive and resistive currents between the signal conductors and ground. The outer shield is grounded, to prevent capacitive coupling of the common mode potential on the inner shield into other circuitry. In many cases, the second (outer) shield may be omitted with no deterioration in performance. 2-33. Input Connector Wiring for Non-Guarded

Preamplifiers. 2-34. The following instructions are for wiring the input connector using either single or double shielded cable. a. Loosen the 10G3-34FW connector cable clamp screws. b. Slide the dressed end of the cable into the cable clamp and through the connector shell. c. Remove and store the guard shield extension. d. Solder the cable center conductors to connector pins A and B. See Figure 2-5. e. Solder the cable shield(s) to pin C. f. Press the connector block carefully into the connector shell, allowing the cable to pass through the connector clamp. g. Insert the retaining ring. h. Tighten the cable clamp screws.

Figure 2-5. Input Connector Wiring, Non-Guarded

2-35. Input Connector Wiring for Guarded

Preamplifiers. 2-36. The following instructions are for wiring the input connectors using either single or double shielded cable. a. Loosen the 10G3-34FW connector cable clamp screws. b. Slide the dressed end of the cable into the cable clamp and through the connector shell. c. Slide the guard shield extension down over the cable shield(s) and onto the guard socket. d. Solder the cable center conductors to pins A and B. See Figure 2-6. e. For single shield cable, solder the cable shield to the guard shield extension. f. For double shield cable solder the inner (guard) shield to the guard shield extension, and solder the outer shield to pin C. Check that shields are not shorted to each other or to the connector shell. g. Press the connector block carefully into the connector shell, allowing the cable to pass through the cable clamp. h. Insert the retaining ring. i. Tighten the cable clamp screws.

2-3

Figure 2-6. Input Connector Wiring, Guarded

2-37. 8805A CARRIER PREAMPLIFIER INPUT

CABLES. 2-38. Carrier preamplifier operation requires both a non-guarded signal input cable and a carrier refer- ence cable, connected between the strain gage or transducer and the 7702A System. A cable assembly for use with Sanborn transducers is shown in Figure 2-7. Cables for other applications are assembled following the instructions in Paragraph 2-41.

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(2) Connect the cable to jack J1 (for channel 1) or jack J2 (for channel 2), located on the rear panel of the recorder. b. Carrier Reference Cable. (1) Connect a twoconductor shielded cable to the 10B9-5MW connector, supplied as an accessory with the system. Solder the two cable conductors to pins A and B, cable shield to pin E.

(2) Connect the cable to jack J21 (for channel 1) or jack J22 (for channel 2) located on the rear panel of the recorder.

2-43. 8806B PHASE SENSITIVE DEMODULATOR

SIGNAL CABLES. 2-44. Demodulator preamplifier operation requires both a signal input cable and a servo reference cable. Construction of the cables is described below. 2-45. Construct the two-conductor signal input cable with a guard shield (see Paragraph 2-

35)

if a high common-mode rejection is desired. If high commonmode rejection is not required, the input cable is wired with an unguarded, single-shield cable (see Paragr aph 2-

33). Connect the signal input cable to J1 (channel 1) or J2 (channel 2). 2-46. Construct the servo reference cable using twoconductor shielded cable and the 10B9-5MW con- nector supplied as an accessory with the system. Normal connection uses a single-shielded cable, in a nonguarded circuit. Solder the "+" servo ref erence signal to pin K, and the "-" servo reference to pin F. Connect the servo reference cable to J21 (c hannel 1) or J22 (channel

2), located on the rear panel of the 7702A Recorder.

2-39. Cable Assembly for use with Sanborn Transducers. 2-40. Use the cable assembly no. 5060-4602 (Figure 2-7) to connect Sanborn Series 267, 268 and 270 Series Transducers to the 7702A System. T his Y-cable contains both a signal input cable and a carrier reference cable.

2-41. Instructions for Assembling Signal Input and Reference Cables. 2-42. Signal input and carrier reference cables for carrier preamplifier applications described in the instruction manual IM-8805A-1 are assembled as follows: a. Signal Input Cable. (1) Connect a two-conductor shielded cable to the 10G334FW connector, supplied as an accessory with the system. Solder the two cable conductors to pins A and B, cable shield to pin C (see Paragraph 2-33).

2-4

2-47. SIGNAL MONITOR CONNECTIONS. 2-48. The preamplifier single-ended output s ignals are available at J21 (channel 1) and J22 (channel 2), located on the rear panel of the recorder. Signal output is pin D, signal common is pin H. For 8803A High Gain Preamplifier, signal out is pin A, signal com mon is pin B. The 10B9-5MW mating connectors are supplied as accessories with the system. 2-49. REMOTE RECORDER OPERATION. 2-50. The 7702A Recorder chart drive ST ART- STOP function and the MARKER function can be con- trolled from a rem ote location. The circuits required ar e shown in Figures 2-8 and 2-9. 2-51. Remote Chart Drive START-STOP Control. 2-52. Construct the circuit shown in Figure 2-8. The 10A5-3MW remote run connector and the 10A5lFWA cable c lamp are supplied as accessories with the system. Any length of four conductor cable may be used. The remote run circuit plugs into the J13 jac k on the rear panel of the recorder.

Figure 2-8. Remote Run Circuit Diagram

2-53. To operate the recorder using the REMOTE RUN circuit, switch the LOCAL-REMOTE switch S3 located on the rear panel of the recorder to the REMOTE position and press the desired speed pushbutton on the recorder front panel. Operate the remote STANDBY-RUN switch to control chart drive. 2-54. Remote Marker Control. 2-55. The marker may be operated from a remote location or from the recorder front panel. To operate the marker from a remote location, construct the circuit shown in Figure 2-9. The connector 10G2-22MW is supplied as an accessory with the system. Any length of cable may be used. 2-56. The Remote marker circuit plugs into the J15 jack on the rear panel of the recorder. 2-57. Auxiliary Marker Operation. 2-58. To operate the auxiliary marker, available as 7702A Option 15, construct a switch circuit as shown in Figure 2-9. Plug the switch into the auxiliary marker Jack J14, located on the rear panel of the recorder.

TM 11-6625-2751-14&P

Figure 2-9. Remote Marker Circuit Diagram

2-59. INITIAL SYSTEM CHECK. 2-60. The following procedures are designed to check the recorder drive, marker, timer, and re- mote control functions. To check the operation of the preamplifiers, refer to the instruction manual for the 8800 Series preamplifiers installed in the system. 2-61. Review the installation process, checking the cables and connectors. Tighten all connections. Check that the S3 power line switch (see Figure 3-3) indicates the correct voltage. The recording system may be damaged if the switch is set to the incorrect voltage range. 2-62. Install a roll of Permapaper in the recorder, following the instructions in Figure 3-4. 2-63. To Check Recorder Drive Functions. a. Press the POWER pushbutton. The panel indicator lamp will light. b. Press the MM/SEC pushbutton. c. Press each of the four speed-pushbuttons. Check for proper paper travel at each speed selected. If recorder is equipped with mm /min speeds, Option 11 or Option 12, press MM/MIN pushbutton. Press each of the four speed-pushbuttons, check ing for proper paper travel at each speed selected. d. Adjust the stylus HEAT controls for a dense, well-defined baseline. 2-64. To Check Recorder Marker and Timer

Functions. a. Press the MARKER pushbutton. A mark will be recorded on the lower edge of the chart. To check remote marker operation, connect the circuit shown in Figure 2-9 to J15. b. Press MM/SEC and TIMER pushbuttons. A one per second timing mark will be recorded on the lower edge of the chart. Press TIMER again to re- lease pushbutton. If system is equipped with mm/min timer, Option 13 or 14, press MM/MIN and T I MER pushbuttons . A one per minute timing mark will be recorded on the chart.

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Figure 2-10. System Controls

2-6

SECTION III. OPERATION

3-1. INTRODUCTION. 3-2. The basic function of the 7702A System is to produce graphic tracings on two-channel thermal sensitive Permapaper, using the heated stylus recording technique. Input signals are amplified by the 8800 Series signal conditioning preamplifiers, and displayed on 50 mm-wide channels on the chart paper. Preamplifiers contain amplitude calibration standards which can be recorded on the chart paper when desired. The chart paper time scale unit is adjus table in fixed steps by the setting of the pushbutton chart speed controls. Standar d recorder speeds provide time scale calibration ranging from 1 m m/sec to 100 mm/sec. W ith Option 11 (60 Hz) or Option 12 (50 Hz), four chart speeds are added which provide time scale calibration from 1 mm/min to 100 mm/ min.

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3-3. CONTROLS AND CONNECTORS. 3-4. Front and rear panel controls and c onnec tors ar e shown in Figures 3-2 and 3-3.

3-5. OPERATING PROCEDURES. 3-6. The 7702A System is ready for use following

installation, discussed in Section II. Figure 3-4 describes the Permapaper loading procedure, and Figure 3-5 provides step-by-step operating instructions, for normal operation of the instrument. Figure 3-6 provides instructions for rem ote operation of the c hart drive s tart stop and marker functions.

Figure 3-1. Typical 2-Channel Recording

3-1

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1 STOP pushbutton switch (momentary). Controls chart drive. 2 CHART SPEED pushbutton switches select chart speed. Pressing any of four pushbuttons starts chart drive at

speed selected. 3 MM/SEC-MM/MIN pushbutton switches. Selects mm/sec drive speeds for standard recorder. Selects mm/min drive speeds when Option 11 or Option 12 is installed in recorder. 4 TIMER pushbutton switch (push on, push off). Initiates one per second timing pulse on lower edge of chart. One per minute timing pulse is available (Option 13 and Option 14) for use with mm/min drive speeds. 5 MARK pushbutton switch (momentary). Controls operation of marker at lower edge of chart. Reference mark is recorded when pushbutton is pressed. 6 POWER pushbutton switch (push on, push off). Controls line power to the recorder. Indicator lamp to the right of the power switch lights when the power is on.

7 9 DAMPING controls. Adjusts the amount of feedback from the galvanometer windings to the driver amplifiers, to

obtain optimum galvanometer pulse response. One control per channel

8 10 HEAT controls. Adjusts amount of stylus heat to obtain the desired trace intensity. One control per channel

11 PREAMPLIFIER controls. Refer to the preamplifier instruction manuals for a description of the panel controls.

Figure 3-2. Front Panel Controls

3-2

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1 SIGNAL INPUT connector. Input for Channel 2. 2 SIGNAL MONITOR connector. Output of Channel 2 preamplifier, for connection to

monitoring instruments. Includes connections for carrier excitation and servo reference voltages.

3 REMOTE MARK jack. Mates with external marker switch circuit, for control of

marker on chart paper. 4 SIGNAL INPUT connector. Input for Channel 1. 5 SIGNAL MONITOR connector. Output of Channel 1 preamplifier, for connection to

monitoring instruments. Includes connections for carrier excitation and servo reference

voltages. 6 AUXILIARY MARK jack. Mates with external switch circuit for control of auxiliary

marker on chart paper. 7 POWER INPUT connector. Mates with power cable supplied with the instrument. 8 LINE VOLTAGE slide switch. Controls power supply input connections. CHECK THAT

SWITCH IS SET FOR NOMINAL VOLTAGE OF EXTERNAL POWER SOURCE. 9 FUSE holder. Contains the input power fuse (1.5 amp slow-blow for 115 volts, 0.8 amp

slow-blow for 230 volts). 10 REMOTE RUN connector. Mates with external switch circuit for control of recorder

chart drive start-stop function. 11 LOCAL-REMOTE switch. Selects either front panel switch or remote run circuit for

control of recorder start-stop function. 12 Spare FUSE holder. Contains spare line fuse.

Figure 3-3. Rear Panel Controls

3-3

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RELEASE PAPER TABLE. Turn instrument OFF, and open the recorder cover. Push the writing table lock lever toward the galvanometers.

REMOVE SUPPLY SPOOL. Lift the paper table outward and rest it on the takeup spindle. Lift the supply spool out of the support brackets. Pull the end discs apart to remove the paper core.

RELEASE PAPER TABLE. Turn instrument OFF, and open the recorder cover. Push the writing table lock lever toward the galvanometers.

REMOVE SUPPLY SPOOL. Lift the paper table outward and rest it on the takeup spindle. Lift the supply spool out of the support brackets. Pull the end discs apart to remove the paper core.

Figure 3-4. Permapaper Loading Procedures

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FEED PAPER RNTO DRIVE ROLL. Fold back and crease the paper about 1 inch from the end of the roll. Start chart drive at 5 mm /sec. Insert the paper into the drive roll squarely, so that the entire leading edge of the paper contacts the drive roll. Stop the r ec order when the paper is drawn tightly over the paper table. Lock the paper table.

THREAD PAPER ONTO THE T AKEUP SPINDLE. Turn on chart drive at 5 mm /sec, and loop paper around the spindle tightly. The paper will be drawn onto the rotating spindle. Stop the recorder. (The paper takeup f eature must be used for satisfactory recorder operation.)

RECORDER IS READY FOR USE. Close the recorder cover. A printed star appears on lower edge of chart, 30 feet from end of roll, to indicate remaining footage.

TO REMOVE PAPER AFTER RECORDING. Remove the paper takeup spindle. Press the black plas tic button on the end of the spindle. Pull out the upper and lower ends of the spindle. After sliding the rec ording paper of f, re-install the spindle, lower end first.

Figure 3-4. Permapaper Loading Procedures (Cont.)

3-5

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1 Connect 7702A System to power line, and connect input signals to J1 and J2 on the rear recorder

panel. Rotate preamplifier attenuator or function switch to the OFF position. For 8801A, 8802A

preamplifiers, place signal use-off switch in OFF position. 2 Press POWER pushbutton. Indicator lamp on recorder will light. Allow three minutes warmup time. 3 Balance and calibrate pream plifiers following the procedures outlined in the pream plifier instruction

manual. When making calibration adjustments, set chart drive ON (see Step 4). 4 Press MM/SEC pushbutton, then press "5" pushbutton. Recorder will run at 5 mm /sec chart speed.

(When recording data, press numbered speed pushbutton to suit recording application. Select

mm/min speeds with recorder Options 11 or 12 by pressing MIN pushbutton.) 5 Adjust stylus heat for each channel to obtain a satisfactory trace intensity (when recording data which

is in the upper range of the recorder bandwidth, a higher stylus heat is required for good trace

definition). 6 Press STOP pushbutton to stop chart drive. 7 Press TIMER pushbutton to obtain one per second time markings on recording. For mm/min

speeds, optional timer records one mark per minute. 8 Press MARK pushbutton to record reference marks on lower edge of Permapaper.

Figure 3-5. System Operating Procedures

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REMOTE CHART DRIVE CONTROL

1 Connect the switch circuit shown in Figure 2-8 to J13 on the rear panel of the recorder. 2 Place the LOCAL-REMOTE switch in the REMOTE position. 3 Press speed pushbuttons on the recor der front panel for the desired recor ding speed. W ith r emote

switch in RUN position, chart drive is ON. In STANDBY position, chart drive is OFF.

REMOTE MARKER CONTROL

4 Connect the switch circuit shown in Figure 2-9 to J15 on the r ecorder rear panel. Press the r emote

mark switch to record a reference mark on the lower edge of the Permapaper. 5 For systems with an auxiliary marker (Option 15), connect the switch circuit of Figure 2-9 to J14.

Press the auxiliary marker switch to record a reference mark between channels on the Permapaper.

Figure 3-6. Remote System Operation

3-7

SECTION IV.

PRINCIPLES OF OPERATION

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4-1. INTRODUCTION. 4-2. This section of the manual contains the

principles of operation of the electrical and mechanical components in the 7702A System. A block diagram of the system is shown in Figure 4-1. Introductory paragraphs 4-3 to 4-13 contain basic information on semiconductor diode and transistor circuits used in the recording system.

4-3. BASIC CIRCUITS. 4-4. Diodes. 4-5. Semiconductor diodes are used in the signal

handling circuits and in the power supply rectifier and regulator circuits.

4-6. Diodes are used as lim iters or clipper s in circ uits to remove positive or negative peaks of wavefor m s. T he diode can be used either as a waveform shaping circuit or as a protective device to pr event excessive voltages being applied to a sensitive circuit. Figure 4-2 (a) s hows a limiter which prevents the negative peak of a pulse from going more negative than approxim ately 0.6 volts. Note that for a conducting silicon diode, the cathode voltage is about 0.6 to 0.8 volts more negative than the anode.

4-7. A diode clamper or dc restorer is a c ircuit which establishes either the positive or negative peak of a waveform at a particular dc refer ence voltage to provide a definite baseline voltage for the waveform . Figure 4-2 (b) shows a clamper which provides a baseline of about +20 volts for a negative pulse.

4-8. A diode regulator circuit uses either the constant reverse-bias breakdown voltage characteristics of a zener diode, or the constant forward bias voltage drop characteristic of a s ilicon diode. Power supply reference voltages are generally provided by break-down diodes which maintains a constant voltage when supplied with a reverse-bias voltage greater than their specified breakdown voltage. Regulated voltages can also be provided by a forward-biased silicon diode which maintains a constant 0.6 to 0.8 volt drop. Figure 4-2 (c) shows connections for both types of diodes.

4-9. Transistors. 4-10. Transistors are used throughout the 7702A in

amplifier and oscillator circuit configurations. Vacuum tubes and transistors are functionally similar. In the tube, a small grid-to-ca thode potential controls a large plate to cathode current flow. In a transistor, a small base-toemitter current controls a large collector-to-emitter current. A comparison of basic

Figure 4-1. Model 7702A System Block Diagram

4-1

Figure 4-2. Basic Diode Circuits

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Figure 4-3. Transistor Operation

4-2

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vacuum tube, NPN transistor, and PNP transistor operation is shown in Figure 4-3 (a); indicated current represents conventional flow of positive charges external to the transistor and is not intended to indicate flow of carriers inside the transistor structure. Notice that the effect of emitter-base-collector voltages is totally reversed between NPN and PNP transistors; circuits which are arranged for an NPN transistor usually function normally for a PNP transistor if supply voltages are reversed.

4-11. There are three basic am plifier types, Figure 4-3 (b). These am plifiers are used alone or in com binations to form complex circuits.

4-12. COMPONENT CIRCUIT DESCRIPTION.

4-13. Preamplifiers. 4-14. The principles of operation for the 8800 Series

Preamplifiers ar e contained in the particular preamplifier Operating and Service Manual. A list of the preamplifiers is shown in Section I, Table 1-3. The pream plifier s ignal input connectors (J1, J2) mounted on the rear of the recorder include provision f or us e of a guar d s hield in the signal input cable. Use of a guard shield contributes to a high common-mode rejection ratio when floating input preamplifiers such as the 8803A are installed in the system. Additional information on the preamplif ier guard shield circuit is contained in the preamplifier manual.

4-15. The output signal of each preamplifier is connected to the input of a 7700-02A galvanometer driver amplifier. T he preamplif ier output signals are als o available at connectors J21 and J22 at the rear of the recorder, for connection to oscilloscopes or other monitoring instruments . Signal distribution in the 7702A System is shown in Figure 4-4.

4-16. Driver Amplifiers. 4-17. Two 7700-02A Galvanometer Driver Amplifiers

are mounted on the rear panel of the power supply 7702-

60030. The driver amplifier block diagram is shown in Figure 4-5.

4-18. The input signal and the galvanometer feed-back signal shown in the block diagram are amplified by the balanced amplifier Q1, Q2, and directly coupled to the differential amplifier Q3, Q4. The signal driving Q1 is limited in amplitude by the transistors Q8 and Q9 to a value which will not overload the driver amplifier or drive the galvanometer writing arm excessively. The singleended output from the Q3, Q4 stage is obtained from the collector of Q4 and is fed to the base of Q5. T ransistor Q5 operates as a Class A driver f or the complem entarysymmetry Class B emitter-follower power amplifier Q6, Q7.

The amplifier output is connected to the galvanometer drive coil. A galvanometer feedback signal is obtained from the galvanometer drive coil and velocity coil, and returned as an input to the balanced amplifier.

4-19. FEEDBACK CIRCUIT. The feedback circuit provides an adjustable amount of galvanometer damping and galvanometer frequency compensation to obtain optimum galvanometer transient response and frequency response characteristics. Galvanometer damping is obtained by generating a feedback voltage proportional to the galvanometer coil velocity, and inserting this voltage into the driver amplifier circuit with a polarity as to reduce the coil velocity. Frequency compensation is achieved by an RC network in the feedback c irc uit, which determines the amplitude of high frequency feedback voltages returned to the balanced amplifier.

4-20. The feedback voltage is derived from two sources; the galvanometer velocity coil output, and the voltage drop across R24 (see Figure 4-6). The velocity voltage component is proportional to galvanometer coil velocity, to damp the galvanometer motion. The DAMPING control selects the amount of this velocity voltage component which gives the best damping characteristics. The drive coil current through R24 produces a voltage at the base of Q2 with an amplitude approximately equal to the Q1 input signal due to the high ratio of open loop to closed loop gain. This feedback action forces a current through the galvanometer drive coil alm os t ex ac tly proportional to the input voltage.

4-21. The DAMPING control is adjusted for the best transient response, and the COMPENSATIO N control is adjusted to match the high-frequency roll-off of the galvanometer. Figure 4-7 shows the galvanometer response both in the frequency and time domains to illustrate different degrees of damping.

4-22. The underdamped condition in Figure 4-7 (a) depicts a partially damped system, with the damping supplied only by the shorted coil frame of the galvanmeter. This shorted frame is equivalent to a low resistence, one-turn short-circuited coil winding. The currents induced in this coil frame develop a damping force which is proportional to the coil velocity, and is in a direction as to reduce the velocity. In this case, the galvanometer oscillates around its final value before coming to rest. The overdamped condition is the result of excessive feedback damping voltage. In this case, the galvanometer approaches its final value slowly, giving too slow a rise time for recording short-period transient voltages.

4-23. The ideal waveshape is the result of properly adjusting the feedback voltage. In this case, the galvanometer approaches the final value quickly, and settles to the final value with a slight overshoot (about 4%). This corresponds to 71% of c ritic al damping, which provides the desired transient and frequency response.

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TM 11-6625-2751-14&P

Figure 4-4. Signal Distribution Diagram

Figure 4-5. Model 7700-02A Driver Amplifier Block Diagram

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(a) Transient response, step function input

Figure 4-6. Feedback Circuit-Simplified Schematic

4-24. The frequency response obtained with an underdamped, overdamped and 71% damped galvanometer is shown in Figure 4-7 (b).

4-25. The frequency response for the 7702A Recording System with an 8802A Preamplifier installed is shown in Figure 4-8. The DAMPING c ontrol is adjusted for 0.71 critical damping at 10mm deflection.

4-26. System Power Supply. 4-27. The 7702A System Power Supply (07706-

60030) furnishes operating power for the preamplifiers, driver amplifiers, and the recorder chart drive circuits. The power supply consists of the following sections:

a. ± 18 Vdc unregulated supply.

b. ± 12 Vdc regulated supply. c. 440 Hz oscillator (provides chopper exc itation for

8803A Preamplifier).

d. 2400 Hz oscillator (provides transducer

excitation voltage for 8805A Carrier Preamplifier).

e. Control circuits for the chart drive motor, the

marker and timer assemblies, and the stylus heat circuit.

(b) Frequency response, sine-wave input

Figure 4-7. Galvanometer Frequency Response and

Transient Response

4-28. UNREGULATED DC SUPPLY. The unregulated ± 18 Vdc supply (see Figure 4-9) consists of transformer T1, diodes CR1 to CR8, and the filter capacitors C13 to C16. Each pair of diodes (CR1, CR2, CR3, CR4) connected across the T1 secondar y winding forms a full wave rectifier circuit. The output of the rectifiers is filtered by capacitors C13 to C16. The distribution of the ± 18 volt power in the 7702A System is shown in Figure 4-10.

4-29. REGULATED DC SUPPLY. The regulated ± 12 Vdc supply block diagram is shown in Figure 4-11, and in the schematic diagram at the rear of the manual. The +18 volt and -18 volt unregulated supply outputs are connected to the series regulator transis tors Q1 and Q2, which are controlled by the output of amplifiers Q3 and Q6 in the 868-500A-C6 regulator card. Both regulated voltages are controlled by one

4-5

TM 11-6625-2751-14&P

voltage adjust control, R4. One input of differential amplifier Q4, Q5 is maintained at 6.2 volts by zener diode CR14; the other input is maintained at a fraction of the -12 volt regulated output by the setting of R4. If the 12 volt regulated output voltage should vary slightly, this will appear as a change in input signal levels between the inputs to Q4 and Q5. This change is further amplified by Q3, and applied to the series control transistor Q1, with such polarity as to return the -12 volt regulated output towards its original value. The +12 volt regulated line is controlled in the sam e manner. In this case, one input of the differential amplif ier Q7, Q8 is at ground potential, and the other input is held at a value determined by the voltage divider R12, R13. Assum ing regulation of the -12 volt line, if the +12 volt output should vary slightly, this will appear as a change in input signal levels at the input to Q7, Q8. This change is further amplified by Q6, and applied to the series control transistor Q2 with such polarity as to return the -12 volt regulated power in the 7702A System is shown in Figur e 4-12.

4-30. 440 HZ OSCILLATOR CARD. The 440Hz Oscillator (868-500A-C14) is shown in the block diagram, Figure 4-13. The frequency of the Q12, Q13 Os c illator is determined by the transformer T4 and capacitor C15. Output from T4 drives the power amplifier Q4, Q5. Diodes CR21, CR22 control the

amplitude of oscillation at a level determined by zener diode CR23. The power for the oscillator and power amplifier is provided by the -18 volt unregulated supply through regulator Q3. The base of Q3 is held at -12 volts by the -12 V regulated supply.

Figure 4-8. 7702A System Frequency Response

Figure 4-9. Unregulated ± 18V Supply

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TM 11-6625-2751-14&P

Figure 4-10. Unregulated ± 18 V Power Distribution

Figure 4-11. Regulated ± 12 V Supply

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Figure 4-12. Regulated ± 12 V Power Distribution

Figure 4-13. 440 Hz Plug-In Oscillator Block Diagram With Associated Circuits

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TM 11-6625-2751-14&P

4-31. 2400 HZ OSCILLATOR CARD. The 2400 Hz

Oscillator Plug-In Card (868-500A- C13) is shown in the block diagram, Figure 4- 14. Q20 and Q21 oscillate at a frequency determined by transformer T 7 and capacitors C18 and C19 in parallel. Thermistors TM7 and TM8 provide oscillator stability. Diodes CR25, CR26 control the amplitude of oscillation at a level determined by zener diode CR24. Output from T7 is a 2400 Hz sine wave balanced with respect to ground, which is used as a transducer excitation voltage, and also provides a reference voltage for the 8805A Carrier Preamplifier.

4-32. Oscillator power is provided by the -18 volt unregulated supply through regulator Q19, located on the plug-in card. The base of Q19 is held at a fixed voltage by the regulated -12 volt supply. The Q19 emitter output voltage (approximately 12 volts), supplies the Q20 and Q21 oscillator circuit.

4-33. RECORDER DESCRIPTION.

4-34. Recorder consists of chart drive components to

transport the recording paper past the rec ording styluses onto a paper takeup assembly, and a dual galvanometer assembly. Also included are control circuits for the following functions: chart drive, stylus heat, timer and marker stylus.

4-35. Chart Drive Components. 4-36. The chart drive mechanism consists of: (1) a 450

rpm (60 Hz) synchronous drive motor, coupled to speed reduction gears to obtain chart speeds f rom 1 m m /sec to 100 mm/sec; ( 2) pushbutton actuated c lutch assem blies, located on the reduction gear shafts, to determ ine which of the speed reduction gears are in the drive tr ain for the chart speed selected; (3) a paper drive assembly, which includes a paper supply spool, a brake roll to hold the paper under tension as it passes over the paper table and a paper drive roll driven by the output of the speed reduction gears, and; (4) a paper takeup assembly, which stores the chart paper following the recording process.

4-37. Drive Motor and Speed Reduction Gears. 4-38. The drive motor (B1) is coupled to the input

shaft, see Figure 4-15(a), by means of a drive c hain and sprockets. The input shaft rotates at 300 rpm for the 1 to 100 mm/sec chart speeds (50 or 60 Hz power line). Four additional chart speeds are available (Option 11 or Option 12) with the addition of a second synchronous drive motor. The optional mm/min drive motor (B103) rotates the input shaft at 5 rpm (50 or 60 Hz power line), through a similar sprocket and chain coupling. An overrunning clutch is installed on each drive motor sprocket so that only one motor shaft rotates at a time.

Figure 4-14. 2400 Hz Plug-In Oscillator Block Diagram

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Figure 4-15. Chart Drive Motor and Speed Reduction Gears

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4-39. Two speed-reduction gear assemblies are

included in the recorder. The first speed reduction assembly, Figure 4-15(b), contains a 5:1 speed reduction gears. The second speed reduction, Figure 4-15 (c), contains both 5:1 and 4:1 reduction gears, to obtain a 20:1 overall speed reduction for the second assembly.

4-40. Pushbutton Actuated Clutch Assemblies.

4-41. A spring clutch installed in each of the speed

reduction assemblies permits the reduction gears to be by-passed, resulting in a 1:1 speed ratio. The spring clutches are mechanically linked to the four-speed pushbuttons on the front panel of the recorder by the clutch actuator assembly shown in Figure 4-12 of Section VI. Pressing one of the pushbuttons c auses the appropriate clutch to be engaged for the speed selec ted. Table 4-1 lists the speed reductions in effect for 1 mm/sec to 100 mm/sec recorder operation.

Table 4-1. Speed Reduction Ratios

DRIVE SPEED

SPEED REDUCTION

MM/SEC 1 ST 2 ND

CHART

DRIVE

MOTOR

1 5:1 20:1 5 1:1 20:1

20 5:1 1:1

100 1:1 1:1

CHART

DRIVE

ROLL

4-42. The power flow through the first speed reduction assembly is shown in Figure 4-16. For 1:1 speed r atio, the pushbutton linkage pulls the clutch actuator arm ( 1) away from the clutch housing. This action locks the gear (2) to shaft (3). The resulting power flow by-passes the 5:1 speed reduction gears (4) (5), on the upper end of the two shafts. An overriding clutch, mounted in the gear hub (5) disengages gear (5) from shaft (6). For 5:1 speed transfer, the push-button linkage causes the clutch actuator arm to engage with the clutch housing, preventing the housing from rotating. This action releases gear (2), permitting it to rotate freely on shaft (3). The power flow is from shaft (3) through the reduction gears (4), (5), to shaft (6). Gear (7) then drives the output gear (2).

4-43. The second speed reduction ass embly, which is driven by gear (2), operates in a similar manner. For medical operating speeds, 2.5 to 50 mm/sec, the reduction ratios in the first and second speed reduction assemblies are 2:1 and 10:1.

4-44. Chart Drive Circuits. 4-45. The chart drive circuits are shown in the

functional diagram, Figure 4-17. The diagram shows the recorder with the mm/sec drive motor (B1) and the optional mm/min drive motor (B103).

4-46. The recorder may be connected to either a 115 or 230 volt power line. The switch S2 on the rear of the recorder is set to agree with the line voltage. For 115 volt input, the power line is connected directly to the chart drive circuits from transformer

Figure 4-16. First Speed Reduction Assembly Operation

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TM 11-6625-2751-14&P

T1 terminals 1 and 2. For 230 volt line power, the line voltage is applied to terminals 1A and 2 of transform er T1. Through transf ormer action, the voltage is reduced to 115 volts at terminals 1 and 2 of T1. Ter m inal 2 of T 1 is connected to the upper lead of the mm/sec drive motor. With the mm/min drive motor installed in the recorder, terminal 2 is also connected to the mm/min drive motor. The lower ter minal of the drive motor(s ) is connected to switch S1C. For recorders with mm/sec speeds only, the S1C switch is always in the mm/sec position. For recorders with the mm/min drive motor installed, the switch may be operated to select either the mm/sec or the mm/min drive motor. The chart drive circuit continues to the left of S1C and upward to the STOP switch S1D. When any of the numbered speed pushbuttons is pressed, the STO P switch is closed and drive motor power is applied. Pressing the STOP pushbutton opens the chart drive circuit. With the LOCAL/REMOTE switch in the REMOTE position, the switch circuit shown is connected to the connector J13 for remote control of the chart drive start-stop function.

4-47. Stylus Heat Circuits. 4-48. The stylus heat circuits are shown in the

functional diagram, Figure 4-18. Each recording stylus has a hot wire element which is heated by the ac line voltage (50 or 60 Hz). The line voltage is reduced by the transformers T1, T2, to the level required for the operation of the stylus heat elements.

The temperature of the heated element in each recording stylus is adjustable for setting desired trace intensity. This adjustment is m ade by means of variable resistors R2, R3, which are front panel contr ols marked HEAT. The recorder als o contains a circ uit to s witch the level of stylus heat for each of the selected mm/sec operating speeds. Thus the same trace intensity is obtained for each of the mm/ sec speeds without the need for manual readjustm ent when a different speed is selected. The mm /min speeds do not require a diff erent level of heat for each of the four speeds, so a constant voltage is applied to the stylus circuit for all speeds selected.

4-49. STYLUS HEAT CIRCUITS-CHART DRIVE OFF.

When the line POWER switch S1A is closed, the 115 volts ac line power is present at T1 terminals 1 and 2. Through transform er action, 115 volts is also pr esent at terminals 1 and 1A. For 230 volt power line oper ation, the S2 switch is in the 230 volt position. The line voltage applied to terminals 1A and 2 is stepped down by transformer action so that 115 volts is present at T1 terminals 1 and 1A. W ith the REMOT E/LOC AL switch in the LOCAL position, and the STOP pushbutton press ed, 115 volts is applied to terminals A and E of the T2 primary windings. The T2 secondary voltage (0.75 V) is connected to each stylus, providing a standby heat level.

4-50. STYLUS HEAT CIRCUIT: CHART DRIVE ON. With the power line switch ON and the 1 mm /sec speed pushbutton pressed, the RUN-STOP switch is

Figure 4-17. Chart Drive Circuit

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TM 11-6625-2751-14&P

in the RUN position, and the switch contact adjacent to T2 terminal E is closed. The circuit is completed from terminal E of T2 to the power line input through the 1 mm/sec speed switch; through S1C, S1D, S3, and terminal 1 of T1. For higher speeds, transformer T2 turns ratio tap is changed, resulting in progressively higher stylus heat voltages. A table of T2 output voltages for the various chart speeds is shown in Figure 4-18.

4-51. Marker and Timer Circuit.

4-52. The recorder m ark er and tim er circuitr y is shown

in the functional diagram, Figure 4-19. The following description includes the circuitry for the s tandard 7702A, and for the optional marker and timer features.

4-53. MARKER CIRCUIT. The 7702A Recorder includes a marker assembly for recording a reference mark on the lower edge of the chart. The marker assembly consists of an ac operated marker coil which vibrates a heated stylus attached to the coil armature. The lower end of the marker coil is connected to transformer T 1, terminal 3 (15 Vac). The upper end of the coil is connected to the MARK switch S1E. Press ing the MARK button grounds the upper end of the marker coil, completing the circuit to the grounded T1 c enter tap (terminal 4). The mark er is also ac tuated from a r emote location by connecting a switch circuit to J15.

4-54. AUXILIARY MARKER CIRCUIT. An additional marker, which rec ords on the chart between channels 1 and 2, is available as Option 15. The auxiliary marker is actuated by a switch circuit connected to J14.

Figure 4-18. Stylus Heat Control Circuit

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Figure 4-19. Marker and Timer Control Circuitry

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TM 11-6625-2751-14&P

4-55. TIMER CIRCUIT. The standard 4-speed

recorder, for 60 Hz power line, includes a 14002S Timer Assembly. This timer is actuated by the front panel TIMER pushbutton switch, to record one timing mar k per second on the chart. The timer as sem bly consists of a 1 RPS synchronous timing motor and a magnetic reed switch. The reed switch is wired so that the marker coil is energized each time the switch closes, recording a timing mark on the lower edge of the chart once per second. Plug-in Timer Assembly 14002T is supplied with recorders operation on 50 Hz line power. A second, optional timer can be plugged into J17 on the rear of the recorder to provide minute timing marks for recorders equipped with eight recording speeds. Table 4-2 lists the timing assemblies for use with the 7702A System.

Table 4-2. Timer Assembly Part Numbers

I/SEC. TIMER I/MIN. TIMER

7702A 14002S 14002V (OPT 14)

(60 Hz PWR)

7702A OPT 08 14002T 14002R (OPT 13)

(50 Hz PWR)

4-56. Pressing the power pushbutton closes the line power switch S1A (see Figure 4-19). For 115 volt operation, the S2 switch is in the lower position, and the line power is applied to T1 terminals 1 and 2. Through transformer action, 115 volts is also present on T1 terminals 1 and 1A, to operate the tim er circuit. For 230 volt line operation, T1 steps the line voltage down to 115 volts. Terminal 4 of the mm/sec timer motor B101 is connected to T1 terminal 1A. With the TIMER and mm/sec pushbuttons pressed, T1 terminal 1 is connected to terminal 3 of the mm/sec timer motor through S3, the TIMER switch S1B terminals 7 and 8, and the S1C switch.

4-57. For each one per second closure of the timer switch, current flows from T1 terminal 3 through the marker coil, terminals 1 and 2 of the timer, S1C contacts, the S1B terminals 5 and 6, to ground. Each time the marker coil is energized, the marker stylus records a time mark on the chart.

4-15

SECTION V.

MAINTENANCE

TM 11-6625-2751-14&P

5-1. INTRODUCTION. 5-2. This section provides the maintenance and

service information for the 2-Channel 7702A Recording System. Maintenance information includes perform ance checks (Paragraph 5-5) which can be used as incoming quality control checks or as a performance check after repair; preventive maintenance (Paragraph 5-10); corrective maintenance (Paragraph 5-48); troubleshooting and repair (Paragraph 5-85).

5-3. TEST EQUIPMENT.

5-4. Recommended test equipment for performance

checking, troubleshooting, repair, and for making adjustments is listed in Table 5-1 together with the performance characteristics required. Other test equipment can be used if their specifications equal or exceed those listed. Refer to the Maintenance Alloc ation Chart in the appendix for the required test equipment.

5-5. PERFORMANCE CHECKS.

5-6. General.

tions and to provide a permanent record of the performance of the system . These checks verify proper operation of all circuits in the system and can be used:

a. As part of an incoming inspec tion check of

the component specifications.

b. Periodically, where maximum reliability is

paramount.

c. As part of a troubleshooting process to

locate malfunctioning circuits.

d. After any repairs or adjustments, before

returning the system (or components) to regular service.

5-8. VARIABLE LINE VOLTAGE. 5-9. During the following procedures, the system (or

component) should be connected to the power source through a variable voltage device so that line voltage can

be varied ±10% from nominal (115 or 230 Vac ) to as sur e proper operation of the system under various supply conditions.

CAUTION

5-7. The Performance Checks (Table 5-2) and

Performance T est Card (to be filled out during incom ing inspection) are designed to verify specifica-

Table 5-1. Recommended Test Equipment.

INSTRUMENT TYPE REQUIRED CHARACTERISTICS USE INSTRUMENT

Variable Voltage 115 or 230 volt; 0-130 Vac 2 amp General Test General Radio Controller 0-260 Vac 1 amp Variac

DC VTVM 1 mV to 1000V full-scale Performance Test HP 412A

1 mA to 1 amp and Troubleshooting

Oscilloscope dc to 450 kHz Performance Test HP 120B

10 mV/cm to 10V/cm and Troubleshooting

Power Supply Stable to within 1/10% Signal Source Harrison Lab

output greater than 1.5 volts 808A

Voltage Divider Accurate to 0.05% Performance General Radio

less than 1.5 K ohms Checks

Differential VTVM ±10V with 5-digit resolution Monitor HP 740A, 741A

AVOID DAMAGE BY REMOVING POWER FROM THE SYSTEM PRIOR TO REMOVAL OR REPLACEMENT OF ASSEMBLIES OR COMPONENTS.

RECOMMENDED

5-1

TM 11-6625-2751-14&P

Table 5-1. Recommended Test Equipment (Cont.)

INSTRUMENT TYPE REQUIRED CHARACTERISTICS USE INSTRUMENT

RECOMMENDED

Function Generator Sine Square Oscillator to 150 Hz Signal Source HP 202A AC/DC VTVM 300 volts full-scale Performance HP 410B

Testing Wattmeter 200 watts 50/60 Hz Adjustment Any Stylus Pressure 0-5 grams Adjustment Sanborn 14015A

Tester Frequency Counter To 40 kHz Performance HP 5223L

Checks

Table 5-2. Performance Checks

POWER SUPPLY (07702-60030)

1. ± 12 VOLT REGULATED SUPPLY Regulation: With ± 10% change in line voltage, change in output voltage is 1% maximum (0.12 volt dc). a. Install two 8800 Series Preamplifiers in the 7702A System using a Variac or a similar variable voltage

source to supply line power to the system. For 115 V ± 10% power line, adjust the Variac output to 115 volts. For 230V ±10% power line, adjust the Variac to 230 volts output. See Reference 8, Figure 3-3, Section III.

b. Connect a dc VTVM to the -12V dc test point, which is pin 1 on the upper drive amplifier circuit board 07700-62010. Voltage should be -12 Vdc ± 20 mV. Adjust R4 on the Regulator 868-500A-C6 if necessary.

c. Incr ease the Variac output voltage 10% from the 115 V or 230V level. VTVM reading should c hange no more than 0.12 volts from reading in step b.

d. Decrease the Variac output voltage 10% from the 115 V or 230 V level. The VTVM reading should change no more than 0.12 volts from the reading in step b.

e. Connect the VTVM to the +12 volt test point which is pin 3 on the upper driver amplifier circuit board 07700-

62010. For a line voltage of 115V or 230 V, the test point should read approximately +12 volts. f. Adjust the Variac output ± 10% as described in steps c and d. T he VTVM reading should not vary more

than ± 0.12 volts from the reading in step e. Ripple: With 115 or 230 volt line power, ripple on +12V or -12V supply should not exceed 10 mV pp. Connect a test oscilloscope to the +12 and -12 test points described above. The measured ripple should not

exceed 10 mV pp, for a 115V or 230V line voltage.

2. ± 18 VOLT UNREGULATED SUPPLY Connect the dc VTVM to the following test points, to determ ine whether the +18V and -18V ±2V supply voltages

are present.

+18 V - Pin 7 on the upper driver amplifier circuit board 07700-62010.

-18V - Pin 8 on the upper driver amplifier circuit board 07700-62010.

5-2

Table 5-2. Performance Checks (Cont.)

3. 2400 Hz OSCILLATOR 868-500A-C13 Output voltage and frequency: 14 volts pp each side to ground; frequency between 2.352 kHz and 2.448 kHz. a. Connect a test oscilloscope to J11l pin 4 and pin 1 (com mon). The am plitude of the output should be at

least 28 V pp. b. Disconnect the oscilloscope and connect a frequency counter to the same test points. The frequency

should read between 2.352 kHz and 2.448 kHz.

4. 440 Hz OSCILLATOR 868-500A-C14 a. Connect test oscilloscope to J11 pin 11 and pin 9 (c ommon). The amplitude of the output should be at

least 14 V pp. b. Disconnect the test oscilloscope and connect the frequency counter to the same test points. The

frequency should read between 430 and 450 Hz.

RECORDER

1. STYLUS: MECHANICAL CENTER a. Check the stylus pressure. Correct stylus pressure is 2 to 2-3/4 grams. b. Set the recorder POW ER switch to OFF. The stylus on each galvanometer s hould come to rest at chart

center, ± 1 division.

TM 11-6625-2751-14&P

2. LINEARITY With 8801A, 8802A: 0.25 div. 8803A: 0.25 div (1 m V range 0.35 div). 8805A, 8806B, 8809A: 0.4 div (after

setting mechanical zero of stylus within ± 1 div of chart center and calibrating for zero error at center scale and +20 divisions). 8807A: 0.55 div +0.05 div x scale expans ion, 330 Hz to 5 k Hz (after setting m echanical zero of stylus within ± 1 division of chart center and calibrating for zero error at lower and upper ends of printed coordinates). 8808A: 50 dB span 1.25 div, 100 dB span 1 div (after setting m echanical zero of stylus within ± 1 division of chart center and calibrating for zero error at lower and upper ends of printed coordinates).

a. Connect a precision voltage divider to the signal input connector J1 (Channel 1) or J2 (Channel 2). b. Connect a signal source to the voltage divider input. (A dc source is us ed for the 8801A, 8802A, 8803A,

8809A Preamplifiers.) c. Balance and calibrate the preamplifier using the procedure outlined in the preamplifier instruction manual. d. Set the preamplifier range switch to O FF. Adj ust the pr eamplifier POSIT IO N c ontrol to c enter the s tylus on

the recording chart. e. Set the preamplifier RANGE and GAIN controls to obtain a 20 division stylus deflection; this is the 100%

value. f. Set the voltage divider output in steps of 25% voltage, starting with 125%, and observe the recording:

g. The stylus deflection for each signal level should be within the limit specified above for each preamp.

125% = 25 div deflection 100% = 20 div deflection 75% = 15 div deflection 50% = 10 div deflection 25% = 5 div deflection

5-3

3. FREQUENCY RESPONSE

Preamps Dc to less than 3 dB down at 8801A 125 Hz

8802A 125 Hz 8803A 86 Hz 8805A 104 Hz 8806B With 60 Hz fixed frequency plug-in 12 Hz;

8807A 54 Hz Option 01, 9 Hz 8808A Not Applicable 8809A 125 Hz

The system frequency response and transient r esponse using the dc preamplif iers 8801A, 8802A, 8803A, and 8809A are checked using the following procedure. For other preamplifiers, see the preamplifier manual:

a. Connect the oscillator to the preamplifier input connectors J1 and J2. b. Center each stylus using the preamplifier position controls.

TM 11-6625-2751-14&P

Table 5-2. Performance Checks (Cont.)

400 Hz fixed frequency plug-in 65 Hz;

5000 Hz fixed frequency plug-in 125 Hz

Frequency Response

c. Set the DAMPING controls for each channel full clockwise. d. Record a 2-Hz sine wave at 10 divisions pp amplitude. e. With the oscillator output voltage maintained at the same amplitude, set the oscillator to the frequency

listed above. f. Adjust the com pens ation (C OMP) c ontro l located at the r ear of eac h dr iver amplifier (upper dr iver f or upper

channel) for a 7-div pp recorded signal (3 dB down).

Transient Response

g. Set the oscillator to 2 Hz, square wave output. Adjust oscillator amplitude to obtain a 25 division pp recorder amplitude. (The calibration source within the preamp m ay be used in place of a square wave osc illator to record a step function.)

h. Run recorder at 20 mm/sec or 25 m m/sec (medical speed) and adjust the DAMPING controls for each channel to obtain a 1 division overshoot on the leading edge of the square wave.

Rise Time

i. Run recorder at 100 mm/sec or 50 m m/sec while recor ding above signal. Obs erve the recor ded rise tim e which is the time required for the signal to rise from the zero amplitude level (-12.5 divisions) to the 90% level (+10 divisions).

Preamplifier Rise Time (10 div, 10-90% with 4% overshoot) 8801A 5 msec

8802A 5 msec 8803A 7 msec 8805A 5.6 msec 8809A 5 msec

10 msec = 1 div at 100 mm/sec 10 msec = 1/2 div at 50 mm/sec

5-4

4. DRIFT Line voltage from 103 to 127 volts. Maximum allowable drift for each preamplifier is:

Preamplifier Drift 8801A, 8802A 0.2 div 8803A 0.27 div 8805A, 8806B 0.35 div 8807A 0.005 div x scale expansion + 0.30 div 8808A Not applicable

8809A 0.50 div a. Apply 103 volts ac power line voltage to 7702A System. b. Run the recorder at 5 MM/SEC and center the styli with the position controls. c. Increase the power line voltage to 127 volts ac and observe each stylus trace deviation from the zero

reference point.

5. NOISE (with zero signal input) Preamplifier Noise

8801A 0.2 div pp 8802A 0.2 div pp 8803A 1 div pp max. gain

8805A 0.2 div pp and 1% of chart deflection 8806B 7 µ V x square root of frequency response, referred to input 8807A Baseline offset and/or noise 2 mV rms referred

8808A 50 dB range: 0.8 div, pp

8809A 0.1 div, pp

TM 11-6625-2751-14&P

Table 5-2. Performance Checks (Cont.)

1 div pp min. gain

To input plus 0.025 div x scale expansion 100 dB range: 0.4 div, pp

(With bottom scale input signal)

Table 5-3. Recorder Minor Repairs and Adjustments

PARTS CHECKED DEFECTS NOTED REQUIRED REPAIRS

1. Stylus 1. Bent or twisted writing element. If the writing element is not at a 90% angle to the paper table platen with the stylus at center chart position, non- linearity will result (unequal upscale and downscale deflections).

2. Broken stylus side wire support.

3. Broken writing element welds.

4. Broken connection between side wires and mounting base.

5. Side wires twisted out of parallel with each other.

6. Writing element nicked.

7. Carboned (blackened) writing element. 7. Clean with cleaning fluid.

8. Mounting base contact surface corroded.

9. Stylus mounting adapter corroded. 9. Clean with fine sandpaper being careful

5-5

1. through 6. Defects - Replace stylus.

8. Clean gently with fine sandpaper taking care not to remove contact plating.

not to remove plating on stylus adapter contacts.

Table 5-3. Recorder Minor Repairs and Adjustments (Cont.)

PARTS CHECKED DEFECTS NOTED REQUIRED REPAIRS

TM 11-6625-2751-14&P

2. Platen 1. Carbon buildup (caused by stylus heat too high).

2. Slight nicks or burrs on knife edge. 2. Use fine emery stone to remove all

3. Deep dents, nicks, or burrs on knife edge.

3. Table Plate 1. Carbon, dirt, or other contamination. 1. Clean with Chlorothene.

2. Dents, nicks, or burrs. 2. Remove sharp edges with fine emery

3. Burrs or nicks on radius at bottom of table plate.

4. Pressure Roll 1. Seized oilite bearings. 1. Clean out with Chlorothene and oil

2. Slight burrs or nicks on working surface.

5. Drive Roll Guide 1. Squeaking or chattering from roll guide and table plate.

6. Drive Roll 1. Surface cracks or cuts. 1. Replace Drive Roll. If Permapaper

2. Drive Roll surface slick or dirty. 2. a) Remove Permapaper from

7. Brake Roll 1. Surface cracks. 1. Replace Brake Roll.

2. Surface dirty or slick. 2. Clean surface with Chlorothene. Turn

1. Clean with cleaning fluid such as Chlorothene.

sharp edges.

3. Replace platen (pull platen from table).

stone. Do not cut Permapaper on table plate.

3. Remove sharp edges with emery stone.

bearings sparingly.

2. Remove sharp edges with emery stone.

1. Check for clearance of roll guide edge near Drive Roll. Adjustment can be made by loosening mounting screws and moving Drive Roll Guide away from Drive Roll. See Ref. 20, Figure 11, IPB Section.

CAUTION

Do not run recorder with loose drive roll guide.

winds around Drive Roll, use a bluntedged instrument to cut the paper.

Recorder.

b) Swing the hinged paper guide

upward on the Drive Roll. See Figure 5-1.

c) Clean surface of DriveRollwith a

cloth dampened with Chlorothene with recorder running at highest speed. Do not saturate Drive Roll with Chlorothene and be careful that the cleaning cloth does not get caught in the Drive Roll. Do not install Permapaper until Drive Roll is completely dry.

Brake Roll by hand while cleaning.

5-6

Table 5-3. Recorder Minor Repairs and Adjustments (Cont.)

PARTS CHECKED DEFECTS NOTED REQUIRED REPAIRS

TM 11-6625-2751-14&P

7. Brake Roll (Continued)

3. Brake Roll sticking or jamming. 3. With proper brake adjustment, the Brake Roll should turn smoothly even though a small pressure is required to turn the Brake Roll by hand. Three defects which can cause Brake Roll jamming are: a) Side plate bearing dirty or too tight. b) Brake disc washer not lubricated. c) Brake Roll adjustment too tight.

For lubrication or replacement of Brak e Roll, do the following:

Brake Roll Removal: Turn the brake roll screw at the right end of the Brake Roll counterclockwise until the Allen-head setscrew is almos t f lus h with the c ollar . See Figure 5-3. Push the spring-loaded screw until the right end of the Brake Roll can be pivoted upward. Pull the Brake Roll out of the left table flange.

Brake Roll Lubrication: a. Following the removal of the Brak e Roll

from the recorder , clean the brake disc washer and left bearing with Chlorothene. Replace bearing if defective.

b. Re-oil the bearing and lubricate the

brake disc (cork washer) with a thin layer of No. 39LU-7 grease.

c. Clean and re-oil the right brake roll

support bearing. Replace the bearing if defective.

8. Paper Take-Up 1. Paper too loose or tight on spindle; take-up operates erratically, particularly at low speeds; take-up chatters.

5-7

Re-installation and Adjustment of Brake Roll: Fit the Brake Roll into the left table flange, and push the spring-loaded screw on the right end until the Brake Roll can slide into the right table flange. Adjust for proper paper tension on platen by turning the Brake Roll screw clockwise until the paper is snug, but not tight, on the platen.

1. Adjust the Paper Take- Up assembly as outlined below. If problem is not corrected, lubricate the Paper Take-Up assembly. See Paragraph 5-38.

Table 5-3. Recorder Minor Repairs and Adjustments (Cont.)

PARTS CHECKED DEFECTS NOTED REQUIRED REPAIRS

TM 11-6625-2751-14&P

8. Paper Take-Up (Continued)

Paper Take-Up Adjustment: a) Run recorder at 20 mm/sec or 25 mm/sec for preliminary check of paper tension

between drive roll and take-up spindle. Paper tension should be snug, not tight or loose. Adjust take-up clutch screw cloc kwise, then counterc lockwise until s light finger pressure depresses paper (see Figure 5-7).

b) Run recorder at highest speed and make clockwise and counterclockwise

adjustments until proper paper tension is achieved.

c) Repeat adjustments at slow speeds, then check operation at high, medium and slow

speeds for a check on overall operation of the Paper Take-Up.

Figure 5-1. Recorder Platen and Writing Edge

5-8

TM 11-6625-2751-14&P

PERFORMANCE CHECK TEST CARD

Model 7702A Oscillographic Recording System Tests performed by __________________________ Serial No.____________________________ Date __________________________

Description Check

1. STYLUS MECHANICAL CENTER: CH 1

Each channel ± 1 division from chart center with system power OFF.

2. POWER SUPPLY ± 12 VOLTS NEGATIVE -12 V, adjustable ADJUSTABLE +12V, ±0.5V

3. POWER SUPPLY ± 18 VOLTS UNREGULATED. +18 V ± 2V AMPLITUDE DEPENDS ON LINE VOLTAGE. -18V ±2V

4. LINEARITY:

8801A, 8802A: 0.25 div 8803A: 0.25 div (1 mV range 0.35 div) CH 1 8805A, 8806B, 8809A: 4 div 8807A: 0.55 div + 0.05 div x scale expansion CH 2 8808A: 50 dB span: 1.25 div

100 dB span: 1 div

5. FREQUENCY RESPONSE WITH DC PREAMPS:

dc to 3 dB down at CH 1

8801A 125 Hz 8802A 125 Hz CH 2 8803A 86 Hz 8809A 125 Hz

6. DRIFT: Line voltage from 103 to 127 V

CH 2

+12V ripple, O1mV pp

-12V ripple, 10mV pp

8801A, 8802A: 0.2 div CH 1 8803A: 0.27 div 8805A, 8806B: 0.35 div 8807A: 0.005 div, CH 2

x scale expansion +0.30 div 8808A: does not apply 8809A: 0.50 div

5-8 (a)

7. NOISE: With zero signal input 8801A: 0.2 div pp

8802A: 0.2 div pp 8803A: 1 div pp max gain

1 div pp min gain 8805A: 0.2 div pp +1% of chart deflection 8806B: 7 µ V x square root of frequency

response, referred to input. 8807A: Baseline offset and/or noise

2 mV rms referred to input plus

0.025 div x scale expansion 8808A: 50 dB range: 0, 8 div pp 8809A: 0.1 div pp

TM 11-6625-2751-14&P

PERFORMANCE CHECK TEST CARD (Cont.)

CH 1 CH 2

5-8 (b)

5-10. PREVENTIVE MAINTENANCE.

5-11. Preventive maintenance is recommended every 1000 hours of operation or every six months , depending upon the operating conditions. Table 5-3 is recommended as a check chart for preventive maintenance as well as an aid for minor repairs and adjustments.

5-12. Mechanical

TM 11-6625-2751-14&P

b. Paper Take-Up. Inspec t paper on take-up spindle. If it is too loose or excessively tight, see Table 5-3.

c. Paper Tension. Inspect paper travel over the writing edge at the highest MM/SEC speed. The paper should remain tight against the edge during travel, not curve over it. To adjust the brak e screw, see Table 5-3.

5-13. Refer to Initial System Check in Section II and perform these checks before continuing.

5-14. Switch power to the system OFF. Inspect the system for symptoms of mechanical or electrical overload. Check for dents, rust, corrosion, or other evidence of mechanical or electrical abuse. Check that all system components ar e securely mounted, including the cable connectors. Check the cables for strain, breaks, frayed insulation.

5-15. The following steps will check the recorder mechanical operation:

a. Paper Loading. Load Permapaper in the recorder. Apply power and run two feet of paper at the highest paper drive speed to correct any mistracking resulting from paper loading. Appr oximately 3/32 in. of the platen table surface should be visible to the right of the chart. Check that paper take-up is working properly.

d. Paper Tracking. Run approxim ately 5 feet of chart at the 50 mm or 100 mm speed with one channel stylus centered. Remove the recording and measure the peak-to-peak varaition of the trace due to paper drift. The tracing should not vary more than 0.5 mm from center. If paper weave exceeds the limit, check paper loading techniques and paper tension. Check Table 5-3.

e. Paper Parallax. Check parallax with paper drive motor OFF and Permapaper tight against the writing edge. With the side of a pencil, mar k the outer edges of the two channels on the recording paper precisely where the paper is angled over the knife edge of the platen. The two points marked on the recorder must lie within 0.25 division of each other on the timing lines. If not, check paper loading technique and brake roll tension.

f. Writing Stylus. Remove each stylus by loosening clamping screw and disconnecting the stylus heat wires (see Figure 5-2); lift stylus from

Figure 5-2. Stylus Adjustment Screws and Limits

5-9

holder. Inspect the writing surface. It should be clean and straight. If the stylus is bent, it som etimes can be straightened with tweezers; if not, replace it. If the stylus is burred or twisted, replace it. Insert a good stylus in galvanometer clamp and secure in place. The flexible stylus heater leads should not touch the adjacent side panel. Tighten the stylus heat lead screws. The ribbon

must be at 90° to the writing edge to obtain the correct stylus overhang. See Figure 5-10. With correct overhang, the middle 1/3 of the ribbon contacts the writing edge when the stylus is positioned from one edge of the chart to the other.

NOTE

Improper overhang can result in poor trace definition across the channel, an erroneous indication of system nonlinearity.

g. Stylus Pressure. When pressure is too light, the trace will be faint and not clearly defined. When pressure is too high, friction will cause noticeable hysteresis and non-linearity. Refer to Paragraph 5-42 f or adjustment procedure.

TM 11-6625-2751-14&P

5-18. Cleaning. 5-19. The cleaning procedure outlined below should

be performed at intervals determined by environmental conditions.

a. Remove power from the s ystem. Rem ove any dust or dirt accumulation on the recorder with a vacuum hose.

b. Clean all front panels, controls, etc., with a clean, lint-free cloth, or with a wax im pregnated polishing cloth. Wipe the viewing window with a cloth moistened with water.

c. Remove Permapaper and clean deposits from the writing edge of the recorder platen with a cleaning fluid, such as Chlorothene. Clean the Drive Roll and the paper Brake Roll with Chlorothene. See T able 5-3. Use it sparingly and let rolls dry thoroughly after cleaning.

h. Marker Stylus. Inspect the marker for cleanness and good mechanical condition. Run a few feet of recording at highest chart speed with the marker button held for continuous operation. Inspect the recording. If unsatisfactory, replace the stylus.

i. Stylus Heat. Apply power to system, set paper drive to 20 mm/sec or 25 mm/sec, -and adjust each Stylus Heat control for best trace. Rotate POSITION control on each preamplifier from one extreme position to the other and observe the corresponding channel recording. Trace definition should be the same over the entire channel width. In case of a sudden change in definition at one point, inspect the writing surface beneath the paper f or a nick or burr at that point. If the change in definition extends over some portion of a channel's width, check for a defective or improperly inserted stylus. Check Table 5-3. Maximum trace definition is obtained using Sanborn Permapaper.

j. Stylus Deflection. With the preamplifier POSITION controls set alternately to the extreme rotation points, check the stylus deflection. The mechanical stops on the galvanometers should limit deflection to not more than 2 m m beyond the edge of the recording channel or 1 mm when motion is toward an adjacent marker. See Paragraph 5-46.

5-16. Electrical. 5-17. The only electrical checks to be made are

included in the Performance Checks for the system. Electrical checks for the preamplifiers are contained in the preamplifier instruction manuals.

d. Clean each stylus with Chlorothene. Do not use steel wool or any cleaner containing abrasive m etal particles.

5-20. Lubrication. 5-21. Lubrication of the paper Brake Roll and the

Paper Take-Up assembly should be performed each 1000 hours of recorder operation.

5-22. Lubrication of the chart drive m echanism gears and clutches is performed during each recorder overhaul. Lubrication interval is also dependent upon recorder usage. Recorders operating for long per iods in the upper half of the speed range require lubrication every 1000 hours. If the recorder is run at the slower speeds for extended periods, more fr equent lubric ation is required. Further, whenever an extended recording period is anticipated (on line for 30 days or more), drive gear lubrication and recorder overhaul prior to the recording period will help to assure uninterrupted service.

5-23. BRAKE AND DRIVE ROLL MAINTENANCE

PROCEDURES.

5-24. Brake Roll Lubrication.

a. To lubricate the Brake Roll, r emove it from the recorder. Turn the Brake Roll Allen-head screw at the right end of the Brake Roll counter-clock wise until the screw is almost flush with the collar (see Figure 5-3). Push the spring-loaded screw until the right end of the Brake Roll can be pivoted upward. Pull the Brak e Roll out of the left table flange as shown in Figure 5-4.

5-10

Figure 5-3. Brake Roll Adjusting Screw Location

b. Following the removal of the Brake Roll from the recorder , clean the brake disc washer and left bearing with Chlorothene. Replace bearing if defective.

c. Lubricate the bearing with 39LU-8 oil, and lubricate the brake disc (c ork washer) with a thin layer of No. 39LU-7 grease.

d. Clean and re-oil the right brake roll support bearing. Replace the bearing if defective.

5-25. Brake Roll Adjustment. 5-26 Permapaper in recorder. Unlock and open the

paper table. Insert Allen wrench into the end of the Brake Roll, as shown in Figure 5-3. Turn the screwdriver five turns counterclockwise, thus releasing the brake mechanism in the Brake Roll.

TM 11-6625-2751-14&P

Re-lock the paper table and run the recorder. T he paper should travel loosely over the platen. Unlock and raise the paper table and turn brake adjusting screw cloc kwise about 1/2 turn increasing the brake tension. Lock paper table and run recorder. Repeat the clockwise adjustment until the paper is pulled snugly over the platen edge by the braking action.

5-27. After completing the above adjustment, check the paper speed accuracy (+ 1%) using the following procedure. If the paper runs too slowly, adjust the brak e screw slightly in a counterclockwise direction. If the paper is too loose, adjust the screw clockwise.

5-28. To check the paper speed, pr es s the TIMER and SEC pushbuttons on the recorder. Run the recorder at the speeds listed in Table 5-4 (Page 5-12),

Figure 5-4. Brake Roll Removal

5-11

for the time intervals indicated in the second column. For the 100 mm/sec paper speed, the paper length should be 200 divisions + 2 divisions between three successive timing marks on the record.

Table 5-4. Timing Calibration

SPEED IN TIMING INTERVAL PAPER MM/SEC in SEC LENGTH 100 2 200 div+2 div 20 10 200 div+2 div 520 100 div±1 div

1 100 100 div±1 div

5-29. Drive Roll Replacement.

a. Remove the recorder from the mobile cart or cabinet, and place on a clean work area.

b. Remove the recorder top and bottom covers (Items 4 and 28 in Figure 2, IPB Section).

TM 11-6625-2751-14&P

d. Unscrew and remove the left side bearing

and bearing retainer (see Figure 5-6).

e. Unfasten the two #4 screws which fasten the ten-button push switch to the recorder side plate and swing the switch outward.

CAUTION

THE SPEED PUSHBUTTONS HAVE CONNECTORS WHICH MUST BE FREED FROM THE CLUTCH CAMS AS THE SWITCH ASSEMBLY IS PIVOTED OUTW ARD. (SEE FIGURE 8, REF. 14, IX SECTION).

f. Unscrew and remove the r ight side bearing and bearing retainer (see Figure 5-6).

g. Remove the paper table from the recorder by lifting the right side of the table upward and outward. (See Figure 5-6.)

c. On the top s ide of the recorder , rem ove the three gears adjacent to the left side bearing retainer. Note the location of the shims on the gear assemblies, so that the shims can be reassembled correctly. See Figure 5-5.

h. To separate the Drive Roll from the table

assembly, spread the side plates slightly.

i. Install a new Drive Roll, following the above

procedure in the reverse order.

j. Us e care in attaching the pus hbutton switch connectors over the cams, so that the cams or the pushbutton switch linkages are not bent out of adjustment. Be sure that buttons are center ed in panel holes, and do not bind when activated.

Figure 5-5. Bearing Retainer and Gears

5-12

5-30. BRAKE ROLL OR DRIVE ROLL SERVICE PROBLEMS. If any of the following symptoms are

evident in the recorder, it is probable that it could be caused by Brake Roll or Drive Roll malfunction:

a. Paper not tracking properly, i. e., paper

moves to one side or the other.

b. Paper weaving, i.e., moves side-to-side in

regular pattern.

c. Chattering noise, i. e., uneven tension

cause by dry cork disc or bad bearing.

d. Irregular paper speed, i. e., speed range

drops or paper stalls.

TM 11-6625-2751-14&P

e. Uneven paper tension over platen, i. e, paper on one end of platen is tight, loose on other end.

5-31. PAPER NOT TRACKING PROPERLY. The surface of the Drive or Brake Roll becomes slick from paper residue after long usage, preventing proper traction. A worn roll can be determined by inspection and touch after it is cleaned with Chlorothene.

NOTE

New rolls have a rippled surface that disappears shortly after use. Loss of ripple does not indicate a bad roll. Other indications that the roll is deteriorating are minute surface crack s or inability to maintain proper speed. Correct fault by replacing defective roll.

Figure 5-6. Paper Table Removal

5-13

5-32. PAPER WEAVING. If the rolls are not worn (see

Paragraph 5-31), weaving is caused by dirt or other foreign matter on the rolls. Clean with Chlorothene. Also, play in the spindle support from the left spindle support spring can cause paper weave. To increase the spring pressure, simply remove the spindle and gently push the spring slightly inward. Too much spring action can cause spindle hub wear.

5-33. CHATTERING. This is usually caused by lack of lubrication on the brake roll cork disc, which causes positive traction instead of the slipping action desired, or a defective brake. Check the bearings for out-ofroundness, too tight fit of roll stud and bearing, presences of burrs or foreign matter. Brush wash with Chlorothene (do not submerge bearing in fluid); rem ove burrs; check f or out-of-roundness. Lubric ate with 39LU8 oil. Chattering is also due to lack of shaft A or B clutch lubrication.

5-34. IRREGULAR PAPER SPEEDS. Most problems that cause irregular speeds can be attributed to Drive and/or Brake Roll trouble: roll needs cleaning, disc needs lubricating, etc., see preceding paragraphs.

5-35. UNEVEN PAPER TENSION. The brake roll causes this uneven pulling on the paper. W hen the cork disc is dry (no lubricant), there is no slipping action and the brake roll tension becom es constant at the disc end, pulling the paper taut over the platen edge. Follow brake roll removal and disc lubricating procedures.

TM 11-6625-2751-14&P

5-36. PAPER TAKE-UP MAINTENANCE

PROCEDURES.

5-37. Paper Take-Up Adjustment.

a. Run recorder at 20 mm /sec or 25 m m/ sec for preliminary check of paper tens ion between drive roll and take-up spindle. Paper tension should be snug, not tight or loose. Adjust take-up screw clockwise, then counterclockwise until slight finger pressure depresses paper.

b. Run recorder at highest speed and make clockwise and counterclock wise adjustm ents until proper paper tension is achieved. (See Figure 5-7).

c. Repeat adjustments at slow speeds, then check operation at high, medium and slow speeds f or a check on overall operation of the Paper Take-Up.

d. Check that the spindle is free to turn in the bearing located in the upper paper take-up housing. If there is insufficient bearing clearance for the spindle to rotate, ream out the bearing slightly.

5-38. Paper Take-Up Assembly Lubrication. 5-39. The Paper Take-Up spindle is driven by the

chart drive motor, from a pulley on one of the drive shafts (see Reference E, Figure 5-11). A composition belt couples power from this pulley to the pressure disc assembly in the lower paper take-up housing. The pressure disc functions as a slipping clutch,

Figure 5-7. Paper Take-Up Adjustment

5-14

maintaining constant tension on the take-up spindle. Smooth operation of the Paper Take-Up depends on lubrication of the cork disc. If the lubrication is insufficient, the paper take-up assembly will operate erratically and the drive belt will wear excessively.

5-40. Perform the f ollowing lubrication procedur e if the Paper Take-Up Assembly malfunctions, or during a scheduled lubrication of the recorder.

TM 11-6625-2751-14&P

end facing the adjusting setscrew (Ref erence 26, Figure 7, IPB Section).

f. Adjust the paper take-up adjustm ent screw as directed in Paragraph 5-36.

g. Check the take-up belt at 1000 hour intervals and replace when badly frayed.

a. Remove the spindle from the Paper Take-

Up assembly. Remove the recorder bottom cover.

b. Remove the two screws which fasten the lower paper take-up housing to the front panel (Reference 30, Figure 7, IPB Section). Remove the paper take-up drive belt from the pulley on the drive shaft.

c. Separate the two halves of the housing. The sections are joined by two roll pins and a nut and screw mounted under the chrome plug buttons.

d. Remove the adjusting setscrew from the pulley assembly. Disassemble the remaining items in the pressure disc assembly, noting the parts locations.

e. Clean all parts with Chlorothene. Lubricate the cork disc with 39LU-7 grease. Reass emble and reinstall the paper take-up housing. Note that the pr ess ur e disc spring is installed with the turned-in

5-41. STYLUS ADJUSTMENTS AND REPAIRS.

5-42. Stylus Pressure. 5-43. Check stylus pressure with the calibrated

pressure gage SN 14015A (see Figure 5-8). Lift the stylus at the center of the heating element support wire, with the gage perpendicular to the writing arm. Run the recorder at 5 mm/sec speed. Lift the stylus with the gage until the stylus stops writing on the paper. The gage should read between 2 and 2-3/4 grams. If the pressure is not correct, adjust the stylus pressure. T he stylus pressure adjusting screw is located on the top of the galvanometer assembly (see Figure 5-2). Remove the preamplifiers, and insert screwdriver through the access holes shown in Figure 5-9. Turn clockwise for less pressure and counterclockwise for more pressure. The adjustment should be made 1/4 turn at a time. Check that the stylus remains level with the paper for correct definition.

Figure 5-8. Calibrating and Measuring Stylus Pressure

5-15

5-44. Stylus Mechanical Stop. 5-45. The mechanical stops prevent the stylus

excursions from exceeding 2 mm beyond the channel edge or 1 mm toward an adjacent marker arm. Set these limits by loosening the stylus Travel Adjustment screw with a screwdriver, setting the stops and tightening the screw. Refer to Figure 5-2 for screw location.

5-46. Stylus Mechanical Center (Zero). 5-47. Before mak ing the following adjustment, be sure

that the Permapaper feeds through the recor der c or rec tly with no weaving or sliding to one side.

a. Set the recorder power switch to OFF.

b. Loosen the setscrew at the bottom of the stylus adapter slightly (Figure 5-10) with a spline wrench.

c. Mechanically swing the stylus adapter with the spline wrench to the desired position and tighten the setscrew. This adjustment may have to be done repeatedly as tightening the setscrew may move the setting. The final check of the stylus center position is

made with the recorder running. ± 1/2 div from centerline is allowable.

d. Adjust the stylus pressure as described in Paragraph 5-42. Stylus pressure must be correct for proper sensitivity and damping.

TM 11-6625-2751-14&P

5-48. CORRECTIVE MAINTENANCE.

5-49. Disassembly of System Components. 5-50. Model 7702-OlA Recorder Assembly Removal:

a. To remove the Recorder Assembly from the 1069-02A Mobile Cart, remove the four front panel screws, disconnect all cables attac hed to the rear of the recorder, and lift the RecorderAssembly upward.

b. Model 7702A Option 01 Recording System; the recorder is removed f rom the rack by unscrewing the four front panel screws, disconnecting all cables attached to the rear of the recorder, and sliding the recorder outward.

c. Model 7702A Option 02 Recording System; the recorder is removed f r om the portable trans it c ase by removing the four fr ont panel screws after dis connecting all cables at the rear of the recorder, and sliding the recorder out of the case.

5-51. Model 7700-02A Driver Amplifier Rem oval; both driver assemblies are mounted on the rear of the power supply. Unscrew the rear panel (Item 36, Figure 2, IPB Section) to gain access to the driver assemblies. Each driver assembly is fastened to the power supply with two captive mounting screws.

5-52. Model 868-500A-C13, 868-500A-C14, 868500A-C6 Plug-in Circuit Board Removal; each of the circuit boards is fastened to the power supply with two mounting screws. Remove the screws and pull the circuit board from the mating connector.

Figure 5-9. Stylus Pressure Adjustment

5-16

Figure 5-10. Heated Stylus Part No. 398

TM 11-6625-2751-14&P

5-53. Model 14002S (60 Hz), 14002T (50 Hz) MM/ SEC Timer Assembly Removal; the mm/sec timer assembly (Reference 35, Figure 2, IPB Section) is located on the left end of the power supply. Remove the recorder top cover, and the three screws on the top bar that secure the power supply. Unfasten and remove the rear plate of the recorder. Unplug the cable which connects to the preamplif ier input connectors, and swing the power supply outward. Remove the two screws which fasten the timer assembly to the power supply.

5-54. Timer As sembly Removal; the optional mm/min timer assem bly (Reference 37, Figure 2, IPB Sec tion) is located on the rear of the power supply. Remove the two mounting screws on the base of the timer.

5-55. Power Supply Assembly 07702-60030 Removal; to gain access to the components inside the power supply, remove the recorder top cover (Reference 4, Figure 2, IPB Section). Remove the three screws in the top bar (Reference 25) which fasten the power supply to the bar. Remove rear plate from recorder. Unplug the cable which connects to the preamplifier input connectors. Swing the top end of the power supply outward.

5-56. DISASSEMBLY AND LUBRICATION OF

CHART DRIVE COMPONENTS.

5-57. The recorder chart drive gears, clutch assemblies and drive chains should be inspected and lubricated each 1000 hours of recorder operation.

5-58. The disassembly and lubrication of the drive shafts and the components mounted on them is accomplished one shaft at a time. After one shaft is serviced, it is replaced in the recorder and another s haft removed. Shaft disassem bly and lubrication procedures are given in Paragraph 5-61. Lubrication of the drive motor sprock ets and chains, mounted on the outside of the recorder side plates, is given in Paragraph 5-72.

5-59. Chart Drive Lubricants. 5-60. The required lubricants for use in the c hart drive

mechanisms are listed in Table 5-5.

Table 5-5. Lubricants

Lubricant Part No. Application 39LU-7 Gears 39LU-8 Oilite bearings, miniclutches 39LU-10 Sprockets, chains

5-17

5-61. Shaft Disassembly and Lubrication 5-62. The six shafts in the chart drive mechanism are shown in Figure 5-11. To gain access to the shafts, remove the left side plate, Refer ence 45, Figure 2, IPB Section. Also remove the top and bottom cover plates on the recorder. 5-63. Shaft A Servicing.

a. Loosen the setscrews on the gears and collars on the shaft. Do not loosen or tighten the setscrews on the nylon gear hub. Press a speed pushbutton which lifts the clutch bracket clear of the clutch sleeve. With a long bladed s cr ewdriver, pus h s haf t A out of the recorder side plates, as s hown in Figure 5-12 (a). Do not allow the gears or clutch to drop, otherwise they may be damaged.

CAUTION

IF A NYLON GEAR IS STRIPPED OR CHIPPED, THE NYLON FIBERS MAY BECOME IMBEDDED IN ADJACENT GEARS, DAMAGING THEM. TO PREVENT THIS DAMAGE, W ASH ALL GEAR TEETH WITH A SOLVENT, THEN INSPECT THE GEARS WIT H A MAGNIFYING GLASS TO DETECT SMALL NYLON PARTICLES.

b. Lay the parts on a clean work area in the order that they are removed from the s haft. See Figure 5-12 (b). Wash the parts in a solvent such as Chlorothene, making sure all gear teeth are thoroughly cleaned. Do not submerge Item 4, hub assembly, in solvent, or the solvent will wash out the oil in the oilite bearing. When clean, check all parts for excessive wear.

c. Gr ease the outer surface of the clutch shaf t adapter with 39LU-7 lubricant. See Figure 5-12 (c).

d. Coat the inner surface of the clutc h spring with a thick layer of grease, as shown in Figure 5-12 (d).

e. Install the clutch spring on the clutch shaft adapter. The end of the coil with the upturned tab m ust be placed on the adapter first. Fill the adapter and spring completely with grease so that there is no air pocket. Heavily coat the outer surface of the spring with greas e. See Figure 5-12 (e).

f. Heavily coat the inner surface of the clutch sleeve with grease.

TM 11-6625-2751-14&P

prevent the escape of grease. Force the clutch hub into the clutch spring with a twisting motion. If the clutch hub is prevented from bottom ing by the grease packed in the spring, unplug the hole to allow some of the grease to flow out. Remove the whole clutch assembly from the shaft. See Figure 5-12(h).

i. Install shaft A in the recorder with the parts in the sequence shown in Figure 5-12 (b). Position all parts in the correct locations, and tighten the setscrews on the shaft flats. Position gear 1 on the shaf t to obtain about 0.004" end play.

j. After installing the shaft, check the clearance between the clutch sleeve and the clutch bracket (Reference 5, Figure 12, IPB Section). When the bracket is disengaged fr om the clutch sleeve by the action of the pushbutton speed switches, the clearance between the sleeve and the bracket should be about

0.015" (see Figure 5-13). The brack et mounting screw can be loosened and the bracket position shif ted slightly to obtain the correct clearance.

5-64. Shaft B Servicing. 5-65. The lubrication procedur e for shaf t B is sim ilar to the procedure for shaft A. The shaft B gear loc ated on the outside of the side plate must be loosened to permit the shaft to be pulled out of the recorder. Establish

0.004" shaft end play by setting the position of the gear on the left end of the shaft.

5-66. Shaft C Servicing.

a. Loosen the shaft collar and gear on the right end of shaft C. Slowly pull the shaft to the right about 2" while holding the miniclutch gear (see Figure 5-

14). A shim washer may be found between the miniclutch gear and the left side plate. W ash the clutch gear with solvent and inspect the inner surface of the hub for wear. Wash the m iniclutch rollers with solvent, and inspect the rollers for excessive wear.

b. Making sure all clutch springs are in their proper location, install the miniclutch in the gear hub with a twisting motion. When the clutch is half way in the hub, liberally oil the miniclutch using 39LU-8 lubricant. Complete the re-assembly, taking car e that none of the clutch springs slip out of position.

g. Slide the clutch assembly, Figure 5-12 (f), onto the shaft. Coat the clutch hub and gear ass embly with grease. See Figure 5-12 (g).

h. Slide the clutch hub onto the shaft. Plug the hole in the flange of the shaft adapter with a tool, to

c. Return the shaft assembly to its proper

position. Lock the collar on the shaft to obtain

0.004"shaft end play while pushing the shaft as far left as possible.

5-67. Shaft D Servicing. 5-68. The inspection and lubrication procedure for shaft D is the same as that outlined for shaft C.

5-18

TM 11-6625-2751-14&P

Figure 5-11. Chart Drive Shafts

5-19

5-69. Shaft E Servicing.

a. Wash the gears with solvent and inspec t f or worn or broken gear teeth.

b. If gear replacement is necessary, set the collar on the shaft for 0.004" end play.

TM 11-6625-2751-14&P

5-79. The platen table locking mechanism and galvanometer assemblies are linked together so the writing styli move up, out of the way of the table. This helps prevent styli damage during paper loading. However, a large paper loop over the platen will dam age

the styli if the stvli are dropped heavily on the paper. 5-70. Shaft F Servicing. 5-71. Use the same procedure as for shaft E. 5-72. Drive Motor Sprocket and Chain Lubrication.

a. To gain access to the mm/s ec drive motor sprockets and chain, remove the top cover of the instrument.

b. Grease the drive motor sprockets and chain with 39LU-10 lubricant.

c. Oil the miniclutch in the sprocket hub with 39LU-8 oil.

d. For recorders equipped with a mm/ min drive motor, remove the recorder bottom cover and lubricate the sprockets and chains as outlined above. 5-73. Gear Lubrication.

5-74. Apply 39LU-7 grease to all gear teeth in the chart drive mechanism. Run the drive motor to run off any excess grease. Switch the recorder power OFF, and wipe away any excess grease.

5-75. Results of Incorrect Lubrication Procedure. 5-76. Figure 5-15 illustrates excessive wear on the

clutch and hub assemblies. T hese parts will wear when the gears have been run for long periods of tim e without a maintenance check or wrong methods of packing the clutches or the wrong grease used. Trouble will also be evident if the recording paper is allowed to double around the drive roll of the recorder and ja m the drive roll gears to a sudden stop. If paper j amming happens and is corrected, but the gears tend to run roughly or c hatter, turn the power off and locate the damaged part immediately. Damaged clutch sleeves result when there is not enough clearance between the clutch sleeve and the bracket.

5-77. GALVANOMETER ASSEMBLY.

5-78. The individual galvanometers for both channels are alike except that a mar ker assem bly is added to the channel 2 galvanometer. These c onventional D’Arsonval moving coil galvanometer s have the coil mounted in the air gap between the poles of the large U-shaped Alnico magnets.

5-80. Galvanometer Magnet Replacement. 5-81. The galvanometer magnet is replaced only if

there is physical damage to the magnet or if the galvanometer shunt cannot be adjusted to the required sensitivity (see Paragraph 5-84 for sensitivity check). Normal magnet strength is 8000 gauss. To replace a magnet, do the following:

a Remove the stylus from the galvanometer.

b. Unscrew the magnet from its mounting plate. See Reference 36, Figure 6, IPB Section. The front screw is made accessible by opening the paper table. The rear screw is m ade ac c ess ible by unfastening the power supply. See Paragraph 5-55.

c. In remounting the replacement magnet, adjust the position of the magnet us ing the screw at the rear of the mounting plate (Ref erence 33, Figure 6, IPB Section) to obtain the correct stylus overhang. See Figure 5-10(c). 5-82. Galvanometer Insert Replacement.

5-83. The coil is rigidly suspended on torsion wires inside the coil housing which is mounted in the air gap of the magnet. The bottom tor sion wire is rigidly clamped to hold the coil so oriented with respect to the housing that, when assembled in a complete r ecorder, the stylus will maintain a zero-signal position at the center of the recording chart. The torsion wires thus function not only to suspend the coil, but also like the spring in a meter movement, to provide restoring torque to return the stylus to zero when no signal information cur rent passes through the coil, and to determine the position of the stylus when signal currents pass through the coil.

5-84. Each galvanometer has an adjustable magnet shunt permanently mounted to the side at the pole pieces. The magnet shunt has two functions: (1) to adjust sensitivity of the galvanometer, and (2) when fully pulled in, to maintain the magnet gauss at full s trength if the galvanometer insert is removed from the magnet. When the shunt is fully pulled in, it can be seen in the hole of the shunt housing (see Figure 5-2).

a. Rotate the shunt adjusting screw c lockwise until the shunt is visible in the hole of the shunt housing.

5-20

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Figure 5-13. Clutch Sleeve Clearance

CAUTION

ONLY WHEN TH E SHUNT IS VISIBLE IS IT SAFE TO REMOVE THE COIL FR OM THE MAGNET WITHOUT LOSING THE MAGNET GAUSS.

b. Remove the stylus from the galvanometer

by loosening the clamping screw (see Figure 5-2).

c. Remove the screws attaching galvanometer insert to the block (see Figure 5-2).

d. Attach identifying labels to the wires connected to the galvanometer insert, then disconnect the wires from the insert. Gently pull the insert from the magnet.

e. Use masking tape to remove all foreign matter from the magnet gap. T he m agnet m ust be clean of filings or chips.

f. Gently lower the new coil into the magnet and attach the mounting screws. Firmly push the galvanometer coil to the front of the magnet and tighten the mounting screws. If there is no mec hanical rubbing when the stylus holder is moved from side to side, the galvanometer is mounted c orrectly. If the galvanometer does touch the sides, the mounting screws must be loosened and the galvanometer recentered in the magnet gap. Adjust the stylus overhang if necessary. See Paragraph 5-81 c.

Figure 5-14. Shaft C Inspection

Figure 5-15. Excessive Wear in Clutch Assembly

5-23

g. Connect all wiring removed from the defective coil to the new coil.

h. Turn the shunt adjusting nut counterclockwise until the shunt is f lush with the rear of the shunt housing.

i. Check the galvanometer coil with the circuit in Figure 5-16. Correct galvanometer sensitivity is 10 divisions for 160 mA current.

TM 11-6625-2751-14&P

5-91. As in most equipment consisting of sub-systems, troubleshooting the 7702A System can be divided into two categories:

a. System troubleshooting, in which the malfunction is identified with a specific subassembly or system function. A defective preamplifier or driver amplifier can be isolated by interchanging the preamplifiers or driver amplifiers in the system. Also, with this substitution method, the galvanometer assemblies can be interchanged by exchanging the wires connected to the galvanometer inserts.

b. Component troubleshooting, in which the defective circuit component such as a resis tor, capac itor, or transistor is identified and r eplaced. The information is contained in Section IV of this manual, and the schematic diagrams for the circuits will be helpful in locating the defective components.

j. Mak e final adjustments of the shunt (either clockwise or counterclockwise) until the 10 divisions deflection for 160 mA current is obtained.

k. All newly installed galvanometer inserts must have the stylus mechanically centered and the stylus stops adjusted (see Paragraphs 5-44 and 5-46).

5-85. TROUBLESHOOTING. 5-86. In troubleshooting the 7702A System, it is

frequently possible to determine the source of the malfunction through the use of the front panel controls. For example, if the position controls on both of the preamplifiers do not affect the position of the styli, the recorder power supply should be checked, since both of the preamplifiers in the system operate from a single power supply.

6-87. Electrical Performance Check. 5-88. Use the Performance Check Card (Page

5-7a/b) and the Performance Check Table (Table 5-2) to check the electrical performance of the 7702A System. As an aid in servicing the system, a Troubleshooting Chart, Figure 5-17 is included which contains a logical procedure for identifying the source of electrical problems in one or both channels of the System.

5-92. Etched Circuit Board Repair. 5-93. The etched circuit boards used in the Model

7702A are of the plated-through type consisting of metallic conductors bonded to a baseboard of insulating material. The m etallic conductors are ex tended through the component mounting holes by the plating process.

5-94. The following are recommendations and precautions pertinent to etched circuit repair work.

a. Avoid unnecessary component substitution; it can result in damage to the circuit board and/or adjacent components.

b. Do not use a high-power soldering iron on the etched circuit boards. Excessive heat may lift a conductor or warp the board.

c. Use a wooden toothpick to remove solder from component mounting holes.

CAUTION

DO NOT USE A SHARP METAL OBJECT SUCH AS AN AWL OR T WIST DRILL FOR THIS PURPOSE. SHARP OBJECTS MAY DAMAGE THE PLATED-THROUGH CONDUCTOR.

d. After soldering, remove excess flux from the soldered areas and apply electrical varnish or lacquer to protect against contamination and corrosion.

5-89. Mechanical Problems. 5-90. Minor mechanical problems and their remedies

are listed in Table 5-3. In addition, this section contains procedures for adjusting and replacing, if necessary, components in the chart drive mechanism and galvanometer assembly.

5-95. Component Replacement. 5-96. Apply heat carefully to avoid damage to the

plated-through conductor holes and to the replacement component. The following is recommended:

a. Remove defective component.

5-24

b. Melt solder in component lead holes. Use

clean, dry soldering iron to remove excess solder.

c. Bend lead of replacement component to correct shape and insert com ponent into the lead holes. Using heat and solder sparingly, solder leads in place. Heat may be applied to either side of the board. A heat sink (longnose pliers, heat-sink tweezers, etc. ) should be used when replacing transistors and diodes to

TM 11-6625-2751-14&P

prevent excessive heat from being conducted to the component.

d. Through-hole plating breaks are indicated by the separation from the board of the round conductor pad on either side of the board. To repair breaks, press conductor pads against the board and solder replacement component lead to conductor pad on both sides of the board.

5-25

MAINTENANCE NOTES

TM 11-6625-2751-14&P

5-26

TM 11-6625-2751-14&P

SECTION VI.

UPDATING SUPPLEMENTS

UPDATING SUPPLEMENT NO. 1

INTRODUCTION

This change sheet updates the instruction manual by detailing the changes that transform the Model 7702A

Oscillographic Recording System into a Model 7702B. The changes are divided into three catagories, as follows:

Designation Options Equipment

The following paragraphs describe these changes in detail.

DESIGNATION

The designation for the recorder assembly, the basic unit, has been changed from Model 7702-01A to 7702B.

OPTIONS

All present options for the 7702A apply to the 7702B except that Option 01 has been dropped and Option 05 has

been added to denote that the 7702B can be obtained in a Model 1069A-02A Mobile Cart.

EQUIPMENT

Equipment changes are prim arily changes in connectors and the wiring pin assignments of these connectors, as

detailed below. Circuit and wiring changes are shown on the schematic diagram, Drawing 07702-91000.

Connector Change

J1, J2 Changed from 3-pin guarded twinax input connec tors to

5-pin guarded connectors to permit trans ducer excitation and returning signals to appear on the same connector.

J3 Changed from a 14-pin connector to a 20-pin connector.

This change increases the number of possible connections and allows the carrying of a separate ground lead between each preamplifier and power supply common.

6-1

Connector Change

J11, J12 Change in pin assignm ents. The 440 Hz excitation has

been made single-ended; pin 9 of the connectors is now wired directly to pin C of connectors J1 and J2.

J13 Changed from a 5-pin connector to a 6-pin connector to

prevent customers from accidentally plugging transducers and ECG patient cables (with 5-pin connectors) into it.

J21, J22 Changed from 9-pin connectors to 10-pin connectors.

Pin assignments have also been changed, and a 115V/230V AC line has been wired to pins H and K. This connection permits the feeding of AC power to the preamplifier by a simple jumper plug.

The above changes require the addition of a jum per from pin 9 to the chassis in the 8800 Series Pr eamplifiers or

the 860-4300 Data Amplifier with a Production Change Order Number lower than 17-15945.

Table 1 provides parts inform ation for the connector s used in the 7702B Recorder. Connec tors not listed are the

same as those used in the 7702-01A Recorder.

TM 11-6625-2751-14&P

Table 1. Connector Data

REF. MATING CONNECTOR

DESIG. FUNCTION DESCRIPTION PART NO. PART NO. J1, J2 Signal Input Male, 5 pins 1251-1894 1251-1895* J3 Internal Conn. Female, 20 pins ** *** J11, J12 Preamp Conn. Female, 16 pins 1251-1842 1251-1843 J13 Remote Conn. Female, 6 pins 1251-1599 1251-1957 J21, J22 Auxiliary Conn. Female, 10 pins 1251-1945 1251-1944

* Requires:

(1) Rubber Bushing 0340-0404 ** Kit not available, consists of: (1) Female Block 1251-1001

(1) Guide Socket 1251-1005 (1) Guide Pin 1251-1006 (1 pair) Catch Lock Spring 1251-1694 (A/R) Contact Socket 1251-1606

6-2

TM 11-6625-2751-14&P

*** Kit not available, consists of:

(1) Male Block 1251-1381 (1) Guide Socket 1251-1005 (1) Guide Pin 1251-1006 (1 pair) Lock Spring 1251-1292 (1) Strain Relief and Hood Clamp 1251-1344 (A/R) Contact Pin 1251-1679

Requires: (1) Cable Clamp 1251-1595

6-3

TM 11-6625-2751-14&P

UPDATING SUPPLEMENT No. 2

GENERAL INFORMATION

Data included in this technical manual for the Model 7702A/B Oscillographic Recording System is also applicable to the 7782A Oscillographic Recording System except for the following:

1. The Model 1069-02A Mobile Cart has been replaced with the Model 1063A Mobile Cart (except Options 002 and 005). Replaceable parts of the Model 1063A Mobile Cart are as follows:

QTY PART NUMBER

2 01062 20014 HANDLE, OLIVE BEIGE

ATTACHING HARDWARE

4 2940 0061 SCREW, 1/4-20 x 1/2 inch

**** 1 01062 60013 CASE, OLIVE BEIGE 2 01063 40011 TRAY, OLIVE BEIGE

ATTACHING HARDWARE

8 2190 0702 WASHER, SHOULDER 8 2190 0760 WASHER, FLAT 8 2680 0103 SCREW, 10-32 x 1/2 inch 2 2740 0003 NUT, 10-32

**** 1 01063 60030 POWER BRACKET ASSEMBLY

ATTACHING HARDWARE

3 2510 0107 SCREW, 8-32 x 1/2 inch

****

DESCRIPTION

6-4

TM 11-6625-2751-14&P

QTY PART NUMBER

2 01511 00070 CLAMP, FRONT LEG

ATTACHING HARDWARE

2 0590 0304 NUT, 1/4-20 2 3020 0006 HEX SCREW, 1/4-20 x 1-1/2 inch

2 01511 00090 CLAMP, REAR LEG

ATTACHING HARDWARE

2 0590 0304 NUT, 1/4-20 2 3020 0006 HEX SCREW, 1/4-20 x 1-1/4 inch

**** 4 01511 60042 LEG ASSEMBLY

2. Option 045 is available for the Model 1063A Mobile Cart. This is a swivel scope mount for the Model 7803B Monitor Scope (see Option 040 for the Model 7782A System).

3. Rack mounting option (Option 001 for 7702A System) is not required f or the Model 7782A. Option 005 provides rack mount when Mobile Cart is deleted.

DESCRIPTION

4. Model 1069-02A Mobile Cart option (Option 005 for 7702B System) is not available for the Model 7782A.

OPTIONS

One or more of the following options may be supplied with the Model 7782A Oscillographic Recording System. NOTE: The 7782A System includes Model 7702B Recorder and Model 1063A Cart (except Option 002). Option 002 Portable Case and Cover (7702-14A), Recorder (7702B) (less preamplifiers)

115/230 volts, 60 Hz.

6-5

TM 11-6625-2751-14&P

Option 003 One channel decrease. Option 005 Delete Mobile Cart (Model 1063A). Option 009 Medical Speeds 2.5, 5, 25, 50 mm/sec 50 Hz. Option 010 Medical Speeds 2.5, 5, 25, 50 mm/sec 60 Hz. Option 011 Eight speed recorder with one minute timer for 60 Hz power line (Adds four mm/min recorder

speeds by means of a 60 to 1 speed reduction and provides one minute timing marks on chart).

Option 012 Eight speed recorder with one minute timer for 50 Hz power line (Adds four mm/min recorder

speeds by means of a 60 to 1 speed reduction and provides one minute timing marks on chart).

Option 015 or Aux iliary marker. Records between channels 1 and 2 on 031 chart paper. Activated by external

control closure.

Option 040 Model 7803B Monitor Scope, Swivel Scope Mount and two interconnecting c ables (14213- 61000)

for 7782A System.

The following options relate directly to the Model 7702B Recorder as part of the Model 7782A Recording System. Options 020 and 025 are incorporated on each system 7702B Recorder while the rem ainder ( Options 008, 013, 014, 018, 019) ar e supplied in accordance with the selected options (listed previously) for the Recording System.

Option 008 50 Hz Operation. Option 013 O ne minute tim er for 60 Hz power line. Provides one per minute tim ing m ark s on c hart. For use

with Option 011.

Option 014 O ne minute tim er for 50 Hz power line. Provides one per minute tim ing m ark s on c hart. For use

with Option 012.

6-6

TM 11-6625-2751-14&P

Option 020 Phone jack outputs [pream plifier output jacks J 23 (Channel 1) and J24 (Channel 2) at Recor der

rear panel] Option 018 2 to 1 speed reductions, 60 Hz. Option 019 2 to 1 speed reductions, 50 Hz. Option 025 White Paint.

REMOVAL/INSTALLATION PROCEDURES -- MODEL 7702B RECORDER IN

MODEL 1062A/1063A MOBILE CART

Remove the recorder from the cart as follows: a. Disconnect all signal cables to the recorder and the power cable from the cart to the recorder. b. Remove six (6) sc rews from each side of the top of the cart. See Figure 1. These screws sec ure the recorder

front panel and the two (2) side top panels (or trays) to the top of the cart.

NOTE: Instead of screws, one (1) corner of either or both of the side top panels

(or trays) may be secured with a transducer holder, or an oscilloscope

mounting bracket, etc. This device must be removed along with the

remaining screws as described in step b. c. Remove the two (2) side top panels (or trays).

DO NOT REMOVE THE TWO LARGE SCREWS WHICH SECURE EACH HANDLE TO THE CART.

CAUTION

6-7

TM 11-6625-2751-14&P

d. Remove the four (4) sc rews from the bottom of the recorder which secure the recorder to the bottom of the cart.

See Figure 2.

NOTE: Access the screws through the bottom of the cart with the cart

standing upright. DO NOT TIP THE CART OVER.

WARNING

LIFTING THE RECORDER FROM THE CART IS A TWO (2)

MAN OPERATION. DO NOT ATTEMPT TO REMOVE THE

RECORDER WITHOUT ASSISTANCE.

e. With one (1) person at each end of the recorder as shown in Figure 3, grasp the recorder securely and lift it

straight up and out of the cart. f. To install the recorder, reverse the removal procedures. g. To disassemble the recorder, refer to the Maintenance Section of this manual.

6-8

TM 11-6625-2751-14&P

UPDATING SUPPLEMENT NO. 3

INTRODUCTION

This change sheet contains desc riptions, Hewlett-Packard stock num bers and wire color codes for AC power cord sets that connect to instruments manufactured by HP Medical Electronics Division.

6-9

TM 11-6625-2751-14&P

NOTE:

OTHER COUNTRIES USE MORE THAN ONE OF THE ABOVE

POWER CORD CONFIGURATIONS. FOR CORRECT POWER

CORD SET IN YOUR AREA, CONSULT YOUR NEAREST HP

SALES OFFICE.

6-10

TM 11-6625-2751-14&P

SECTION VII.

MANUAL CHANGES

(for model 7702A)

MAKE ALL CHANGES IN THIS MANUAL ACCORDING TO THE ERRATA BELOW. ALSO CHECK THE FOLLOWING TABLE FOR YOUR INSTRUMENT CR/PCO NUMBER AND MAKE ANY LISTED CHANGE(S) IN THE MANUAL.

CR/PCO NUMBER MAKE MANUAL CHANGES CR/PCO NUMBER MAKE MANUAL CHANGES ALL ERRATA PCO-17-15921 CHANGE 1 PCO 17-15940 CHANGE 2 PCO 17-15981 CHANGE 3

∆

NEWOR REVISED ITEM

ERRATA: Page 1-3, Figure 1-6;

Change 868-500A-C13 to read 868-500A-C14, 440 Hz Osc. Change 868-500A-C14 to read 868-500A-C13, 2400 Hz Osc.

Page 1-4, Table 1-1;

Change the paragraph marked "T ERMINALS" to read: "Signal input, signal monitor, servo reference, carrier excitation and power line terminals located on rear panel. Remote chart drive and remote marker terminals also located on rear panel."

Page 1-6, Table 1.4;

Change F1 to read Fuse, 1.5 AMP Slo Blo, 115 volt power line; .8 AMP Slo Blo, 230 volt power line. Change J14 to read auxiliary marker. Change J15 to read Remote Marker.

Page 1-7, table 1--5;

Delete Galvanometer stylus part No. 398.

Page 3-2, Item 1;

Change to read: "STOP pushbutton switch.

7-1

TM 11-6625-2751-14&P

MANUAL CHANGES MODEL 7702A (Cont’d)

Note: The following are IPB changes.

ERRATA: Page 4; (Cont’d) Change Ref. No. 7 to read: "Case, Portable (see Figure 22) (Option 02 only).

Page 16, Ref No. 27;

Change to read: Stock No. 3030-0304, Screw, Allen 10-32 1/4.

Page 22, Ref. No. 48;

Change description to read "Motor, 60 Hz (B1)"

Page 24, Ref. No. 10;

Change to read Stock No. 3030-0303, Screw, Allen, 10-32 5/8.

Page 26, Ref. No. 16;

Change to read Stock No. 0361-0416 Trimount. Change Ref No. 37 to 38. Change Ref No. 38 to 37.

Page 38, Ref No. 1; Listing for Figure 19

Add to No. 38B-21 description the designation B101 Add to the Stock No. 38B-21A description the designation B101 Add to the Stock No. 38B-39 description the designation B102 Ref No. 6; Add to description - (S101).

Page 38, Listing for Figure 20;

Ref. No. 1 stock No. 38B-78 description - change to read "Motor, 60 Hz (Used on 7702-60110) (B103). Stock No. 38B-78A desc ription - change to read "Motor, 50 Hz (used on 07702-60220) (B103).

Page 44;

Add the following: Ref. Desig.: B1; Description: Motor, 60 Hz; Sanborn Part No. 38B37; Vendor Part No. NCH-13 RM; Vendor Code: 07829; See Fig. & Index No.: 10-48.

7-2

MANUAL CHANGES MODEL 7702A (Cont’d)

ERRATA: Page 44; (Cont’d)

Delete the following items: C17, LC-1, LC-2. R1: change Figure No. to read "16". R2 and R3: change Fig. and Index No. to 7-8. R4 and R5: change Fig. and Index No. to 7-4.

Page 45;

S1: change to read Part No. 3101-3001, Fig. No. 8-15.

Page 45, Driver Amplifier Assembly;

J1: Change Fig. No. to read 3-9. Q6: Change Fig. No. to read 3-3. Q7: Change Fig. No. to read 3-14. R22: Change Fig. No. to read 3-5. R23: Change Fig. No. to read 3-5.

Page 46; Add the following:

TM 11-6625-2751-14&P

(Timer Assemblies)

Sanborn Vendor Vendor See Fig. &

Desig. Description Part No. Part No. Code Index No. B101 Motor Assy (14002S only) 38B-21 117P 14907 19-1

B101 Motor Assy (14002T only) 38B-21A 117P 14907 19-1 B102 Motor Assy (14002R only) 38B-39 117P 14907 19-1 B102 Motor Assy (14002V only) 38B-39A 117P 14907 19-1

R7 Resistor, 10 Ohms 50AB-100J EB1005 01121 19-4 R8 Resistor, 10 Ohms 50AB-100J EB1005 01121 19-4

S101 Switch, Magnetic reed 62V-1 MRR-1 12617 19-6 S102 Same as S101

(MM/Min Drive Motor Kits)

B103 Motor (60 Hz) 38B-78 B8122EX-300C 07829 20-1 B103 Motor (50 Hz) 38B-78A B8150EX-250C 07829 20-1

C17 Capacitor, .84 µ F 8B-231 YAT-102 14655 20-5

(60 Hz) C17 Capacitor, 1.0 µF 0160-2555 YAT-103 14655 20-5

(50 Hz)

CHANGE 1: Page 46, Oscillator Card Assemblies;

Change Q19 to Part No. 1853-0045, Vendor Part No. 2N4036, Vendor Code 02735. Add C21, Part No. 8B-212, .0056 MF, Vendor Part No. 192P56292-PTS, Vendor Code 56289.

7-3

TM 11-6625-2751-14&P

MANUAL CHANGES MODEL 7702A (Cont’d)

CHANGE 1: Page 49, Schematic Diagram 868-500A-C13, 2400 Hz Osc. (Contd)

Change Q19 to 2N4036. Add .0056 mF capacitor from the emitter to base of Q19.

Page 34;

Change Q19 to Part No. 1853-0045, 2N4036. Add C21 Stock No. 8B-212 capacitor, .0056 µ F, Quantity 1.

CHANGE 2: Page 46, oscillator card assemblies;

Change CR24 to part No. 1902-0551, Vendor Part No. 1902-0551, Vendor Code

28480.

Page 49;

Change the CR24 voltage to read 6.2 volts.

Page 34;

Change CR24 to Part No. 1,902-0551, Diode, Quantity 1.

CHANGE 3: Page 45, Recorder Assembly;

Change R9 to 3300 ohms, Part No. 50AB-323J.

Page 20;

Add Item 53, Stock No. 07702-20020 Spacer, Sideplate, Quantity 1. Add Item 53 Spacer to Page 21, Figure 9. Spacer is loc ated midway between two Ref. 39 spacers on bottom edge of recorder.

7-4

TM 11-6625-2751-14&P

MANUAL CHANGES

(for MODEL 7702-01A, 7702A. 7702B)

MAKE ALL CHANGES IN THIS MANUAL ACCORDING TO THE ERRATA BELOW. ALSO CHECK THE FOLLOWING TABLE FOR YOUR INSTRUMENT CR/PCO NUMBER AND MAKE ANY LISTED CHANGE(S) IN THE MANUAL.

CR/PCO NUMBER MAKE MANUAL CHANGES CR/PCO NUMBER MAKE MANUAL CHANGES ALL ERRATA 17-16915 CHANGE 11 17-15981 CHANGE 4 17-17019 CHANGE 12 17-16057 CHANGE 5 17-17232 CHANGE 13 17-16280 CHANGE 6 17-17508 CHANGE 14 17-16285 CHANGE 7 Serial Prefix 1012A CHANGE 15 17-16414 CHANGE 8 1016A CHANGE 16 17-16860 CHANGE 9 1021A CHANGE 17 17-16903 CHANGE 10

9 - 16860 - 1 10 - 17019 - 2

ERRATA - 3

13 - 17232 - 4 14 - 17508 - 5 16 - 17615 - 6 17 - 17954 - 7

ERRATA - 18029 - 8

7-5

MANUAL CHANGES MODEL 7702A, 7702B

ERRATA: Page 5-3, Table 5-2, Paragraph 4b:

Change frequencies from 430 and 450 Hz to 418 and 462 Hz, respectively.

Page 5-4, Table 5-2, Paragraph 3g:

Change paragraph on Transient Response Test to read as follows:

g. Set the oscillator to 2 Hz, square wave output. Adjust the oscillator amplitude to obtain a 10 division peak to peak chart deflection. (The preamplifier calibration voltage may be used in place of a square wave generator to record a step function.) h. Run the recorder at 20 mm/sec or 25 mm/sec (medical speed), and adjust the DAMPING controls for each channel to obtain a .4 division overshoot on the leading edge of the square wave.

IPB Page 6, Item 8:

Change Stock No. of Rack, Slide and Lock Assembly to 07702-60020.

IPB Page 13, Figure 5: Ch Change lowermost reference 22 (guide pin) to 28.

IPB Page 14, Item 10:

Change location of entry so it appears under Item 17; Board assembly is part of coil and coil/stylus holder.

TM 11-6625-2751-14&P

TRANSIENT RESPONSE

IPB Page 14, Item 17:

Change Stock No. to 608,D- 100-C4.

IPB Page 22, Item 48:

Change Stock No. for Motor 60 Hz to 3140-0397.

CHANGE 4: IPB Page 18:

Add designation (Except Option 10) after items 2, 4 and 5. Add second Item 2, 5000-0308, LABEL, Stick-on (2.5) (Option 10) Add second Item 4, 5000-0312, LABEL, Stick-on (25) (Option 10) Add second Item 5, 5000-031 2, LABEL, Stick-on (50) (Option 10)

IPB Page 7:

Add Item 55, Z Offset Bracket 07702-00067, to parts list.

CHANGE 5: IPB, Page 45, Recorder Assembly:

Change R9 from RESISTOR 4.7K ohms to RESISTOR, 0686-3325, 3.3K ohms, 5%, I/2W, comp, 01121, EB-3325.

Schematic Diagram:

Connect Q3 collector to F2 (0.5A instead of 0.25A fuse shown).

IPB Page 15:

Change Item 39 from 151-2-1001 MAGNET to 00350-63120 MAGNET. Add to Item 4, the 613-100-CI I STYLUS MOUNTING ADAPTER ASSY, (1) Spring, HP Part No. 1460-0945

7-6

TM 11-6625-2751-14&P

MANUAL CHANGES MODEL 7702A. 7702B

IPB Page 30:

Change R6 from 0683-3325 to 0684-2721, 2700 ohms, 10%, 1/4W.

CHANGE 6: IPB Page 46:

Change R6 to RESISTOR, 2700 ohms, 10%, 1/4W, HP Part No. 0684-2721, Vendor Part No. CB-2721, Vendor 01121

CHANGE 7: Throughout manual, change Model Number of System from 7702A to 7702B, and change

Model Number of Recorder Assembly from 7702-01A to 77028. IPB, Table of Contents:

Item 1, change Model Number to 7702B Item 2, change Model Number to 7702B Item 3, change Model Number to 7700-02B and add (See Supplement) Item 13, change Part Number to 07702-61030 Item 14, change Part Number to 07702-61030 Item 7, change Part Number to 07702-60210 Item 23A, change Model Number to 7702B and add (See Manual Changes) Item 23B, change Model Number to 7702B

IPB Page 4,

Item 1, Change Stock No. to 7702B.

Page 6:

Item 1, Change Stock No. to 7700-02B Item 30, Change Stock No. to 07702-61030 Item 51, Change Stock No. to 07702-61040

Page 9:

Delete Information and Insert (See Supplement at Rear of Manual).

Page 12:

Item 11, Change Stock No. to 07702-61200 Item 12, Change entry to read: 1251-1894, CONNECTOR, 5-pin Male Twinax type, (J 1, J2), 2 Item 16, Change Stock No. to 1251-1945 Item 23, Change Stock No. to 1251-1344 Item 25, Change Stock No. to 1251-1381 Add 0683-1005, Resistor, 10 ohms, 5%, 1/4W (R 12) Add 0150-0096, Capacitor, 0.05 mfd, Ceramic (C20)

Page 26:

Item 1, Change Stock No. to 7700-02B Item 2, Change Stock No. to 07702-61040 Item 25, Change Stock No. to 07702-61170

Page 28:

Item 15, Change Stock No. to 07702-61150 Item 16, Change Stock No. to 07702-61160

Pages 2-2, 2-3, 2-4 Replace Figures 2-3 to 2-6 and Paragraphs 2:26 to 2-42 with illustration

sheet INPUT CABLE PREPARATION and SIGNAL INPUT AND AUXILIARY CONNEC-

TORS, Wiring Diagram.

7-7

MANUAL CHANGES MODEL 7702A, 7702B

INPUT CABLE PREPARATION

TM 11-6625-2751-14&P

7-8

MANUAL CHANGES MODEL 7702A, 7702B

TM 11-6625-2751-14&P

Signal Input and Auxiliary Connectors, Wiring Diagram

7-9

IPB Page 47, Figure 23A:

Replace schematic diagram with attached schematic. On the figure supplied, change shields for J 11, Pins 9, 2, 5, 3 and 10 so they are like those on the corresponding pins of J 512. On J 12, Pin 7, add shield like that on J I 1, Pin 7. Change S2 description to 115/230 V.

CHANGE 8: IPB, Page 12, Item 10:

Add to Auxiliary Marker Jack (J 14): 0150-0012, CAPACITOR, C19, 0.01 Mfd, 20%, Ceramic

Page 22, Item 48: Add to 60 Hz Motor BI (Except Option 08) Add the following components to cover Option 08:

3140-0398, MOTOR, 50 Hz (Option 08 only) 0160-2556, CAPACITOR, 0.84 Mfd, C18 (Option 08 only) 07702-00330, BRACKET (Option 08 only)

IPB, Page 2, Also Page 1-7 (Table 1-5):

Change accessory lists to the following list: 1 651 52 PERMAPAPER

1 1251 0405 CONN 2 PIN M 1 1251 0405 CONN 2 PIN M (Option 15 only) 2 1251 0405 CONN 2 PIN M (Option 50 only) 2 1251 1757 CONN 9 PIN M 2 1251 1860 CONN CONT F 2 1490 0797 CORE 1 CH 1 2110 0005 FUSE 1.6A 2 2110 0012 FUSE .5A 1 2110 0020 FUSE .80A 1 2110 0059 FUSE 1.5A 125V 1 8120 1395 PWR. CORD 8-FOOT 1 14015A STYLUS PRESSURE TESTER

TM 11-6625-2751-14&P

MANUAL CHANGES MODEL 7702A, 7702B

Page 1-1:

Add Option 16, 2: 1 Speed Increase, 60 Hz (Deleted by Change 12) Add Option 17, 2:1 Speed Increase, 50 Hz (Deleted by Change 12) Add Option 18, 2: 1 Speed Reduction, 60 Hz Add Option 19, 2:1 Speed Reduction, 50 Hz

CHANGE 9: IPB, Page 12, Item 10:

Change Jacks J 14, J 15 to 1251-2230 Page 2, Also page 1-7 (Table 1-5) Change plug 1251-0405 to 1251-1140.

CHANGE 10: IPB, Page 47, Figure 23A:

Make the following wiring changes to schematic diagram illustrated.

1. Change signal input wires from double shield to single shield.

2. Delete shielded wire between Preamp connector Pin 9 and Input connector Pin C.

7-10

MANUAL CHANGES MODEL 7702A, 7702B

IPB Page 16, Ref 16:

Add the following: 07702-23013, HOUSING, Paper takeup, left, (Option 25 only).

IPB Page 16, Ref 32:

Add the following: 07702-23033, HOUSING, Paper takeup, right (Option 25 only)

IPB Page 16, Ref 33:

Add the following: 07702-00301, FRAME, Door P/O item 18 (Option 25 only)

IPB Page 20, Ref 50:

Add the following: 07702-00021, PAPER GUIDE (Option 25 only)

IPB Page 16, Ref 10:

Add the following: 07702-61061, FRONT PANEL (Option 25 only)

IPB Page 18, Ref 16:

Add the following: 0370-0909, BUTTON (Option 25 only)

IPB Page 45:

Add R10; RESISTOR, variable, 0.5 ohm, 12.5W, W/W (Option 12); 2100-2325; Vendor Part No. E-48253; Vendor 44655.

TM 11-6625-2751-14&P

IPB Page 26, Item 10:

Change Stock No. to 3101-1234.

CHANGE 14: Schematic diagram for Change 7;

Change C2 from .01 MFD to 0.1 MFD. Add R11, 10 ohms, in series with terminal 3 of switch S1-B.

IPB Page 18, Reference 13:

Change C2 to listing to read CAPACITOR, 0. I MFD, QTY 1.

IPB Page 18:

Add Reference 17; RESISTOR, 10 ohms (RI 1) QTY 1.

IPB Page 44, Recorder Assembly Parts List:

Change C2 listing to read, CAPACITOR, 0.1 MFD, 0 50-0084, 8131-100-651-1042,

15450.

IPB Page 45, Recorder Assembly Parts List:

Add R10, RESISTOR, 10 ohms, +5%, ¼/4W, 0683-1005, CB 1005, 01121.

IPB Page 16, Ref 15:

Change to read 1450-0419, PILOT LIGHT, white (I1).

IPB Page 44, Ref I1:

Change to read i1, PILOT LIGHI, white; 1450-0419; 599-237-WHT-TL, NEON; Drake Mfg. Co.; 7-15.

7-13

CHANGE 15: IPB Page 16, Ref 10:

Change Part No. to 07702-61070 (07702-61071 for Option 25).

IPB Page 18, Ref 16:

Change PWR pushbutton Part No. to 07800-00523 (07800-00524 for Option 25).

CHANGE 16: IPB Page 16, Ref 26:

Change Part No. to 1460-1203

IPB Page 12, Ref I:

Delete 07702-00130 and add 07702-00131 (Option 25 only)

Page 1-7, Table 1-5:

Change 3-wire power cord to 8120-1395.

IPB Page 2, ACCESSORIES:

Change power cord to 8120-1395.

IPB Page 26, Parts List for Figure 13:

Change Ref 12 to read 07702-00350

IPB Page 26, Parts List for Figure 15:

Change Ref 11 to read 1251-2357.

TM 11-6625-2751-14&P

MANUAL CHANGES MODEL 7702A, 7702B

IPB Page 44, RECORDER ASSEMBLY Parts List:

Change J9 listing to read, CONNECTOR, Power, 1251-2357, EAC-301, 82389.

Page 1-5, Table 1-2:

Add to noise specification: With 8803A Preamplifier set to max gain and with marker on, 3 Î V (referred to input) noise spikes may be present.

CHANGE 17: Page 1-7, Table 1-5:

Change remote marker plug to 1251-0405.

IPB Page 2, ACCESSORIES:

Change 10OG2-22MW to 1251-0405

IPB Page 44, Recorder Assembly Parts List:

Change C2 to read, CAPACITOR, 0.05 MFD I00 WVDC, Ceramic, 0150-0096, 845-Y5V-5032, 15450, 8-13.

Schematic diagram for Change 7;

Change C2 to .05 MFD. Add R 12, C20 as shown below:

7-14

THE HEWLETT PACKARD MODEL 7702B HAS RECENTLY BEEN MODIFIED TO IMPROVE EITHER INSTRUMENT PERFORMANCE OR PRODUCTION METHODS. THIS PUBLICATION CHANGE NOTICE HAS BEEN ISSUED TO UPDATE EXISTING PUBLICATIONS ON THE INSTRUMENT. ALL INSTRUMENTS IDENTIFIED BY PREFIX DATE CODE

1102A AND HIGHER HAVE BEEN MODIFIED AND REFERENCE TO COMPONENT PARTS, WIRING, OR

INSTRUCTIONS APPEARING IN THE PUBLICATION FOR THE INSTRUMENT SHOULD BE CHANGED AS FOLLOWS:

ON 07702-60000 RECORDER ASSEMBLY

ADD C108 0160-3731 CAP .01M 20% CER ACROSS TERMINALS

27 AND 28 OF S1.

TM 11-6625-2751-14&P

ADD C109 0160-0904 CAP .05M 20% 1000V C109 ACROSS

THE DRIVER MOTOR AT THE MOTOR LEAD TERMINAL BLOCK.

ADD 2 07702-00200 BRACKETS (TOTAL QUANTITY 4).

7-17

TM 11-6625-2751-14&P

THE HEWLETT-PACKARD MODEL 7702B HAS RECENTLY BEEN MODIFIED TO IMPROVE EITHER INSTRUMENT PERFORMANCE OR PRODUCTION METHODS. THIS PUBLICATION CHANGE NOTICE HAS BEEN ISSUED TO UPDATE EXISTING PUBLICATIONS ON THE INSTRUMENT. ALL INSTRUMENTS IDENTIFIED BY ERRATA HAVE BEEN MODIFIED AND REFERENCE TO COMPONENT PARTS, WIRING, OR INSTRUCTIONS APPEARING IN THE PUBLICATION FOR THE INSTRUMENT SHOULD BE CHANGED AS FOLLOWS:

7702B OPTION 20: INSTRUMENTS SUPPLIED WITH THIS OPTION INCLUDE PREAMPLIFIER OUTPUT JACKS J23 (CHANNEL 1) AND J24 (CHANNEL 2), MOUNTED ON THE REAR PANEL OF THE RECORDER. TWO UNWIRED PHONE PLUGS PART NO. 6960-0006 ARE INCLUDED WITH THE INSTRUMENT ACCESSORIES. A SCHEMATIC OF THE OPTION 20 OUTPUT JACKS IS GIVEN BELOW.

7-18

TM 11-6625-2751-14&P

THE HEWLETT-PACKARD MODEL 7702B HAS’RECENTLY BEEN MODIFIED TO IMPROVE EITHER INSTRUMENT PERFORMANCE OR PRODUCTION METHODS. THIS PUBLICATION CHANGE NOTICE HAS BEEN ISSUED TO UPDATE EXISTING PUBLICATIONS ON THE INSTRUMENT ALL INSTRUMENTS IDENTIFIED BY 1136A HAVE BEEN MODIFIED AND REFERENCE TO COMPONENT PARTS, WIRING, OR INSTRUCTIONS APPEARING IN THE PUBLICATION FOR THE INSTRUMENT SHOULD BE CHANGED AS FOLLOWS:

77023 RECORDER

KNOB FROM 0370-0151 KNOB ALL

TO 0370-1005 KNOB

GUIDE FROM 07702-00020 GUIDE

TO 07702-00022 GUIDE

SHIELD FROM 07702-00130 SHIELD

TO 07702-00132 SHIELD

ASSY RACK SLIDE FROM 07702-60020 ASSY RACK SLIDE

TO 07702-60022 ASSY RACK SLIDE 07702-60000 ASSY RECORDER

KNOB FROM 0370-0497 KNOB

TO 0370-1874 KNOB FROM 07800-00533 KNOB

TO 07800-00527 KNOB

00702-60230 ASSY FRONT DOOR

DOOR FRAME FROM 07702-00300 DOOR FRAME

TO 07702-00302 DOOR FRAME

07702-61210 ASSY PANEL

PTU HOUSING FROM 07702-23010 HOUSING

TO 07702-23014 HOUSING FROM 07702-23030 HOUSING

TO 07702-23034 HOUSING

FRONT PANEL FROM 07702-61070 FRONT PANEL

TO 07702-61072 FRONT MBMH,

7-19

TM 11-6625-2751-14&P

THIS NOTICE IS ISSUED TO UPDATE EXISTING PUBLICATIONS FOR HEWLETT-PACKARD MODEL

7702B INSTRUMENTS.

x FOR ALL INSTRUMENTS, MAKE CHANGES IN THIS PUBLICATION ACCORDING TO THE INFORMA-

TION LISTED BELOW:

 FOR INSTRUMENTS HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

07702-63498 ACCESSORY MATERIAL LIST

FUSE FROM 2110-0201 1.5A

TO 21160004 1.5A FROM 2110-0202 .50A

TO 2110-0012 .50A ADD 1251-0405 CONN ON OPT. 20 (2)

1251-0405 CONN ON OPT. 15 (1)

7-20

TM 11-6625-2751-14&P

THIS NOTICE IS ISSUED TO UPDATF EXISTING PUBLICATIONS FOR HEWLETT-PACKARD MODEL

7702B INSTRUMENT(S).

x FOR ALL INSTRUMENTS, MAKE CHANGES IN THIS PUBLICATION ACCORDING TO THE INFORMA-

TION LISTED BELOW:

 FOR INSTRUMENTS HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

 FOR SUBASSEMBLIES HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

Section, 7702A 2-CHANNEL THERMAL RECORDING SUB-SYSTEM; Page 26: Change Part No. of REF# 31 from 66B-199 to 9100-1974.

7-21

TM 11-6625-2751-14&P

THIS NOTICE IS ISSUED TO UPDATE EXISTING PUBLICATIONS FOR HEWLETT-PACKARD MODEL

7702B INSTRUMENT(S).

x FOR ALL INSTRUMENTS, MAKE CHANGES IN THIS PUBLICATION ACCORDING TO THE INFORMA-

TION LISTED BELOW:

 FOR INSTRUMENTS HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

 FOR SUBASSEMBLIES HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

07702-61030 MATERIAL LIST

T2 TRANSFORMER FROM 9100-1933

TO 07702-63600

7-22

TM 11-6625-2751-14&P

THIS NOTICE IS ISSUED TO UPDATE EXISTING PUBLICATIONS FOR HEWLETT-PACKARD MODEL 7702B INSTRUMENT(S).

FOR ALL INSTRUMENTS, MAKE CHANGES IN THIS PUBLICATION ACCORDING TO THE INFORMATION LISTED BELOW: FOR INSTRUMENTS HAVING SERIAL PREFIX AND HIGHER MAKE THE FOLLOWING PUBLICATION CHANGE(S): FOR SUBASSEMBLIES HAVING SERIAL PREFIX AND HIGHER MAKE THE FOLLOWING PUBLICATION CHANGEIS):

7702B MATERIAL LIST

PAPER DRIVE STOP FROM 1530-1287

TO 154-108

7-23

TM 11-6625-2751-14&P

THIS NOTICE IS ISSUED TO UPDATE EXISTING PUBLICATIONS FOR HEWLETT-PACKARD MODEL

7702B INSTRUMENT(S).

 FOR ALL INSTRUMENTS, MAKE CHANGES IN THIS PUBLICATION ACCORDING TO THE INFORMA-

TION LISTED BELOW:

x FOR INSTRUMENTS HAVING SERIAL PREFIX 1540A AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGE(S):

 FOR SUBASSEMBLIES HAVING SERIAL PREFIX AND HIGHER MAKE THE FOL-

LOWING PUBLICATION CHANGECS):

07702-61030 MATERIAL LIST

T1 TRANSFORMER FROM 9100-1974

TO 07702-63500

7-24

TM 11-6625-2751-14&P

PUBLICATION CHANGE NOTICE

THE HEWLETT PACKARD MODEl 7700-02B HAS RECENTLY BEEN MODIFIED TO IMPROVE EITHER INSTRUMENT PERFORMANCE OR PRODUCTION METHODS. THIS PUBLICATION CHANGE NOTLCE HAS BEEN ISSUED TO UPDATE EXISTING PUBLICATIONS ON THE INSTRUMENT.

ALL INSTRUMENTS IDENTIFIED BY 16625 HAVE BEEN MODIFIED AND REFERENCE TO COMPONENT PARTS, WIRING, OR INSTRUCTIONS APPEARING IN THE PUBLICATION FOR THE INSTRUMENT SHOULD BE CHANGED AS FOLLOWS:

07700-62030 PRINTED CIRCUIT BOARD ASSEMBLY

R10 0698-5966 5K 1% ½W CHANGE TO 0757-0367 100K 1% W

07700-92010 SCHEMATIC

CHANGE R10 5K 1% TO 100K 1%

7-25

TM 11-6625-2751-14&P

APPENDIX A

ILLUSTRATED PARTS BREAKDOWN

FOR

Section I. 7702A 2-CHANNEL THERMAL RECORDING SUBSYSTEM

Section II. 7700-02B SYSTEM DRIVER AMPLIFIER

A-1

HP 7702b schematic

Specifications and Main Features

Frequently Asked Questions

User Manual

APPENDIX A