HP 7035B Technical Manual

TECHNICAL MANUAL

HEWLETT-PACKARD MODEL HP-7035B

Section Page

Section Page

I INTRODUCTION ......................................... 1-1

Description .................................................. 1-1

1-2 Basic Frame ..................................... 1-1

1-4 Model-Manual Information.................. 1-1

1-6 Specifications ................................... 1-1

1-8 Options ............................................. 1-1

1-9 Metric Calibration (Option

001) ................................................ 1-1

1-11 X-Axis Retransmitting

Potentiometer (Option 003) .............. 1-1

1-13 Accessories ...................................... 1-1

1-15 Model 7562A Logarithmic

Converter ........................................ 1-1

1-17 Model 7563A Log Voltmeter/

Amplifier ......................................... 1-4

1-19 Model 17108A Time Base.................. 1-4

1-21 Model 10025A Straight-

through Voltage Probe .................... 1-4

1-23 Model 10111A Adapter ...................... 1-4

1-25 Model 10002A/B/C/D

Voltage Divider Probe ..................... 1-4

1-27 Model 11000A Cable

Assembly ........................................ 1-4

1-29 Typical Performance ......................... 1-4

1-30 Input Resistance vs Off

Balance Characteristics ................... 1-4

1-32 Normal Mode Noise .......................... 1-4

1-34 Dynamic Response............................ 1-5

II INSPECTION AND INSTALLATION

2-1 Introduction ....................................... 2-1

2-3 Incoming Inspection .......................... 2-1

2-4 Mechanical Checks ........................... 2-1

2-6 Electrical Checks............................... 2-1

2-8 Damage Claims................................. 2-1

2-10 Storage ............................................. 2-1

2-12 Shipping............................................ 2-1

2-14 Recorder Installation ......................... 2-1

2-16 Cooling ............................................. 2-1

2-18 Stacking H-P Instruments .................. 2-1

III OPERATING INSTRUCTIONS

3-1 Operating Requirements.................... 3-1

3-2 General ............................................ 3-1

3-4 Controls, Connectors, and.................. 3-1

Indicators

3-6 Electrical Requirements ..................... 3-1

3-7 Operating Power ............................... 3-1

3-9 Input Signals ..................................... 3-1

3-11 Grounding ........................................ 3-1

3-13 Recording Input Connections ............. 3-1

3-15 Connection Techniques for

the Guard Shield ............................. 3-1

3-17 Maximum Allowable Source

Impedance ...................................... 3-1

3-19 Operating Precautions ....................... 3-3

3-23 Operating Instructions ....................... 3-3

3-24 Operational Conditions....................... 3-3

3-26 Connect Power ................................. 3-3

3-28 Connect Inputs ................................. 3-3

3-30 Energize Recorder ............................ 3-3

3-32 Install Paper ...................................... 3-4

3-34 Install Pen ......................................... 3-4

3-36 Zero Set ........................................... 3-4

3-38 Lower Pen......................................... 3-4

IV THEORY OF OPERATION

4-1 General Operation

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

4-7 Circuit Description ............................. 4-1

V MAINTENANCE, PERFORMANCE,

CHECKS AND ADJUSTMENTS

5-1 Introduction ....................................... 5-1

5-3 Preventive Maintenance .................... 5-1

5-4 General............................................. 5-1

5-6 Environmental Operation.................... 5-1

5-8 Cleaning ........................................... 5-1

5-10 Potentiometer Cleaning ..................... 5-2

5-12 Lubrication ........................................ 5-2

5-14 Visual Lubrication ............................. 5-2

5-16 Mechanical Maintenance.................... 5-2

5-17 Disassembly/Assembly...................... 5-2

5-19 Carriage Arm Removal ...................... 5-3

5-21 Pen Carriage Removal ...................... 5-3

5-23 Potentiometer Replacement -

X-Axis ............................................. 5-4

5-25 Wiper Replacement - X-Axis .............. 5-4

5-27 Potentiometer Replacement -

Y-Axis ............................................. 5-5

5-29 Wiper Replacement - Y-Axis .............. 5-5

5-31 Servo Motor Maintenance ................. 5-5

5-33 X-Axis Servo Motor

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

5-35 Y-Axis Servo Motor

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

5-37 Brush Replacement .......................... 5-6

5-39 Correction of Sticking

Motor Brushes ................................ 5-6

5-41 Y-Axis Restringing ............................ 5-6

5-43 X-Axis Restringing ............................ 5-6

5-45 Electrical Maintenance ...................... 5-7

5-46 Requirements ................................... 5-7

5-48 Performance Tests ............................ 5-7

5-49 Criteria ............................................. 5-7

5-51 Test Equipment ................................ 5-7

5-53 Initial Checks..................................... 5-8

5-55 Y-Axis Accuracy and

Linearity .......................................... 5-8

5-56 X-Axis Accuracy and

Linearity .......................................... 5-8

5-57 Y-Axis Slewing Speed........................ 5-8

5-58 X-Axis Slewing Speed........................ 5-8

5-59 Common Mode Rejection .................. 5-9

5-60 DC Rejection .................................... 5-9

5-61 AC Rejection .................................... 5-9

5-62 Mechanical Adjustments ................... 5-9

5-63 Procedure ......................................... 5-9

5-65 Y-Axis Drive String Tension

Check/Adjustment ........................... 5-9

iii

TABLE OF CONTENTS (CONTINUED)

Section Page

5-68 Y Gear Train Backlash

Adjustment ..................................... 5-10

5-70 Y-Axis Pen Carriage

Adjustment ..................................... 5-10

5-72 Y-Axis Alignment ............................... 5-11

5-74 X-Axis Cable Tension Check/

Adjustment ..................................... 5-11

5-77 X-Axis Drive Belt Tension

Check/Adjustment .......................... 5-11

5-80 X-Axis Drive Belt Replacement ........... 5-11

5-82 X Gear Train Backlash

Adjustment ..................................... 5-13

5-84 X-Axis Track Bearing

Adjustment ..................................... 5-13

5-86 X-Axis Drive Train Bearing

Replacement ................................. 5-13

5-91 Electrical Adjustments ........................ 5-14

5-92 Gain Adjustment ............................... 5-14

5-94 Calibration Adjustment....................... 5-14

5-96 Phase Shift Adjustment ..................... 5-15

VI PARTS LIST

6-1 Introduction ....................................... 6-1

6-3 Parts List........................................... 6-1

Section Page

6-4 Alphanumerical Table ....................... 6-1

6-6 Miscellaneous Parts .......................... 6-1

6-8 Recommended Spares ..................... 6-1

6-10 Code List of Manufacturers ............... 6-1

6-12 Illustrated Parts Breakdown................ 6-1

VII TROUBLESHOOTING

7-1 Introduction ....................................... 7-1

7-2 Content ............................................ 7-1

7-4 Troubleshooting ................................ 7-1

7-5 Requirements.................................... 7-1

7-7 Troubleshooting Index........................ 7-1

VIII BACKDATING

8-1 Requirements ................................... 8-1

8-2 Definitions ........................................ 8-1

8-4 Change I .......................................... 8-1

8-6 Change II .......................................... 8-3

8-8 Change III ......................................... 8-3

8-10 Change IV......................................... 8-4

8-12 Change V ......................................... 8-4

8-14 Change VI ........................................ 8-7

8-16 Change VII ....................................... 8-7

APPENDIX A REFERENCES ................................. A-1

B MAINTENANCE ALLOCATION.......... B-1

iv

LIST OF ILLUSTRATIONS

Figure Page

1-1 Model 7035B X-Y Recorder.......................... 1-0

1-2 Model 7035B X-Y Recorder- Opt. 001

(With Wing Brackets) ................................. 1-0

1-3 Instrument Identification .............................. 1-1

1-4 Dimension Drawing ..................................... 1-3

1-5 Accessories ................................................ 1-3

1-6 Input Resistance Characteristics .................. 1-5

1-7 Typical Frequency Response

(Input Filter) .............................................. 1-6

1-8 Typical Dynamic Response ......................... 1-6

2-1 Wing Bracket Installation ............................. 2-2

2-2 Stacked Configuration ................................. 2-2

3-1 Front Panel Controls (7035B and

7035B-001) Models ................................... 3-2

3-2 Rear Panel .................................................. 3-3

3-3 Disposable Pen Installation ......................... 3-4

4-1 Block Diagram............................................. 4-2

4-2 Detailed Block Diagram ................................ 4-2

4-3 Range Selector ........................................... 4-3

4-4 Input Filter .................................................. 4-3

4-5 Zero Circuit ................................................. 4-3

4-6 Slidewire and Damping Circuit...................... 4-3

4-7 Photochopper and Balance Circuit ................ 4-4

4-8 Differential Amplifier..................................... 4-4

4-9 Voltage Amplifier ......................................... 4-5

4-10 Amplifier/Demodulator ................................. 4-5

4-11 Motor Control and Demodulator ................... 4-5

4-12 Power and Reference Supply ...................... 4-6

4-13 Neon Driver. ............................................... 4-6

4-14 Autogrip Power Supply ................................ 4-6

4-15 Pen Drop Supply ......................................... 4-6

5-1 Potentiometer Cleaning ............................... 5-2

5-2 Potentiometer Lubrication............................. 5-2

5-3 Tilting Out Entire Circuit Board

Assembly................................................... 5-3

5-4 Side Panel Removal .................................... 5-3

Figure Page

5-5 Pen Scale Removal ..................................... 5-4

5-6 Carriage Arm Removal ................................ 5-4

5-7 Removal of X-Axis Rebalance

Potentiometer ........................................... 5-4

5-8 X-Axis Wiper Protection ............................... 5-4

5-9 Servo Motor Maintenance and

Backlash Adjustments ............................... 5-5

5-10 Nylon Cable (Attachment to Pen

Block)........................................................ 5-6

5-11 Restringing Diagram.................................... 5-7

5-12 Y-Axis Slewing Speed Test Setup................. 5-8

5-13 Slewing Speed Determination....................... 5-9

5-14 X-Axis Slewing Speed Test Setup................. 5-9

5-15 Y-Axis Drive String Tension Check............... 5-10

5-16 Y-Axis Backlash Adjustment

(Gear Adjusting Screw) ............................. 5-10

5-17 Y-Axis Backlash Adjustment

(Gear Locking Screw) ................................ 5-10

5-18 Y-Axis Pen Carriage Adjustment................... 5-11

5-19 Y-Axis Alignment ......................................... 5-12

5-20 X-Axis Cable Tension Check ....................... 5-12

5-21 X-Axis Drive Belt Tension Check ................. 5-12

5-22 Drive Train Adjustments .............................. 5-13

5-23 X-Axis Gear Train Bearings ......................... 5-14

5-24 Circuit Board Adjustment ............................. 5-15

6-1 Exploded View - Cabinet ............................. 6-9

6-2 Exploded View - Carriage Arm

(Sheet 1 of 2) ............................................ 6-10

6-2 Exploded View - Carriage Arm

(Sheet 2 of 2) ............................................ 6-11

7-1 Component Identification -

Frame ....................................................... 7- 8

7-2 Component Identification -

Circuit Board ............................................. 7-9

7-3 Schematic Model 7035B

(D-07035-92550) ....................................... 7-10

8-1 Component Identification - Circuit.................

Board ........................................................ 8-2

8-2 Control Panels - Model S 0735B

and 7035B-001 ......................................... 8-3

8-3 IEC Power Connection ................................ 8-4

8-4 Filling Ink Pen ............................................. 8-4

8-5 Exploded View - Carriage Arm ..................... 8-6

Table Page

1-1 Model 7035B Specifications ......................... 1-2

1-2 Accessory Supplies ..................................... 1-4

5-1 Recommended Test Equipment ................... 5-8

6-1 Parts List .................................................... 6-2

6-2 Miscellaneous Parts .................................... 6-6

LIST OF TABLES

Table Page

6-3 Recommended One Year

Isolated Spare Parts List ........................... 6-7

6-4 Manufacturer's Code List ............................. 6-8

7-1 7035B Troubleshooting Index ...................... 7-2

v

SECTION O

INTRODUCTION

O-1. Scope

This manual contains the general description, installation,
operation, principles of operation, and maintenance of the test
instrument, which is known as the Recorder RO-458(V)1/U
(HP-7035B).

O-2. Index of Technical Publications

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.

O-3. Maintenance Forms, Records and Reports

a. Reports of Maintenance and Unsatisfactory

Equipment. Department of the Army forms and procedures

used for equipment maintenance will be those prescribed by
TM 38-750, The Army Maintenance Management System.

b. Report of Packaging and Handling Discrepancies. Fill
out and forward SF 364 (Report of Discrepancy (ROD)) as
prescribed in AR 735-11-2/DLAR 414.55/NAVMATINST

4355.73/AFR 400.54/MCO 30.3E.

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/MCOP4610.19C/DLAR 4500.15.

O-4. Reporting Equipment Improvement
Recommendations (EIR)

If your Recorder RO-458(V)1/U needs improvement, let us
know. Send us an EIR. You, the user, are the only one who
can tell us what you don't like about your equipment. Let us
know why you don't like the design. Tell us why a procedure is
hard to perform. Put it on an SF 368 (Quality Deficiency
Report). Mail it to Commander, US Army Communications­Electronics Command, ATTN: DRSEL-ME-MQ, Fort
Monmouth, NJ 07703. We'll send you a reply.

O-5. Administrative Storage

For administrative storage of your transmission level and return
loss measuring set, wrap set in heavy kraft paper and tape
securely with packaging tape.

O-6. Destruction of Army Electronics Materiel

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

O-7. Warranty Information

The R0-458(V)1/U (Model HP-7035B) X-Y Recorder is
warranted by the HEWLETT-PACKARD company for one year
from the date of shipment. Warranty period starts on the date
found in block 23 of DA Form 2408-9 in the logbook. Report all
defects in material or workmanship to your supervisor, who will
take appropriate action through your organizational
maintenance shop.

O-1

FIGURE 1-1. MODEL 7035B X-Y RECORDER

FIGURE 1-2. MODEL 7035B X-Y RECORDER - OPTION 001 (WITH WING BRACKETS)

1-0

SECTION I

INTRODUCTION

1-1. DESCRIPTION

1-2. BASIC FRAME
1-3. The Hewlett-Packard Model 7035B X-Y Recorder is a

general purpose laboratory instrument designed for plotting
cartesian coordinate graphs from dc electrical sources.
Specially guarded and shielded circuitry provides one megohm
input resistance at null on all fixed and variable ranges from
100 mV/in. (40 mV/cm) and above. Five calibrated dc input
ranges in each axis, the most sensitive is used
potentiometrically, are standard features. Arbitrary full scale
voltage ranges may be used with calibrated de ranges by using
a variable input attenuator. The Autogrip holddown platen
accepts standard 8-1/2 x 11 inches or smaller graph paper.
The instrument is readily adaptable from bench to rack
mounting by installing the wing brackets provided. See
Figures 1-1 and 1-2 for general configuration.

1-4. MODEL-MANUAL INFORMATION

1-5. This manual is applicable to the Model 7035B with a
serial prefix of 1114A. The serial prefix is the first four digits
and a letter of a two-part ten-item serial number (0000A-

00000) used to identify each Hewlett-Packard instrument (see
Figure 1-3). Should any change to this manual be necessary,
a new serial prefix will be assigned to the changed model and
a change sheet (Manual Change) will be supplied defining the
differences between the changed model and the one described
within this manual.

1-6. SPECIFICATIONS

1-7. Table 1-1 lists the specifications available with this
recorder. Figure 1-4 illustrates the outside dimensions.

1-8. OPTIONS

1-9. METRIC CALIBRATION (OPTION 001)
1-10. Ordering this option will provide a metrically scaled and

calibrated version of this instrument. (HP Service Center
installation only.)

1-11. X-AXIS RETRANSMITTING POTENTIOMETER

(OPTION 003)

1-12. This option provides a potentiometer that is coupled to
the X-axis drive system. The potentiometer is 5K ±3% with
±0.1% linearity, and 0.04% resolution.

1-13. ACCESSORIES

1-14. Accessories supplied with each instrument depend on
the configuration of the instrument, and are listed in Table 1-2.
Other accessories for special applications may be ordered.
These accessories which do not require modification of the
recorder are described in the following paragraphs.

1-15. MODEL 7562A LOGARITHMIC CONVERTER
1-16. The Model 7562A Logarithmic Converter produces de

output voltages in logarithmic relationship to other dc input
voltages, or true amplitude RMS of ac input voltages, in a 10,
000 to 1 (80 dB) amplitude range. The all solid state, single
channel converter allows semilog plotting with X-Y and strip
chart recorders. Two converters may be used for log-log
records. An oscilloscope output is also provided for waveform
monitoring using oscilloscopes. A broad frequency range, 100
kHz to 0.5 Hz, increases its usefulness.

FIGURE 1-3. INSTRUMENT IDENTIFICATION

1-1

TABLE 1-1. MODEL 7035B SPECIFICATIONS

PERFORMANCE

Input Range: 1, 10, 100 mV/in.; 1 and 10 V/in. (Option 001,

Metric calibration: 0.4, 4, 40, 400 mV/cm and
4 V/cm). Continuous vernier between ranges.

Type of Input: Floated and guarded signal pair. Input may be

operated up to ±500 Vdc with respect to chassis ground.
Signal and guard terminals are available at the front panel
or at a rear connector. Mating rear connector supplied.

Range

Standard Metric DC (CMR) AC (CMR)
1 mV/in. 0.4 mV/cm 130 dB 100 dB
10 mV/in. 4 mV/cm 110 dB 80 dB
100 mV/in. 40 mV/cm 90 dB 60 dB
1V/in. 400 mV/cm 70 dB 40 dB
10 V/in. 4 V/cm 50 dB 20 dB

Input Resistance:

Range Input Resistance:

1 mV/in. (0.4 mV/cm) Potentiometric.

(essentially in­finite at null)

Variable 11k

10 mV/in. (4 mV/cm) 100k

Variable 100k

100 mV/in. (40 mV/cm) 1 meg

Variable 1 meg

1 V/in. (400 mV/cm) 1 meg

Variable 1 meg

10V/in. (4 V/cm) 1 meg

Variable 1 meg

Maximum Allowable Source Resistance: 20k ohm on most

sensitive range, no restriction on other ranges.

Normal Mode Rejection (at line frequency): > 30 dB (18

dB/octave roll-off above 60 Hz).

Common Mode Rejection: Conditions for the following data are

DC or line frequency AC with up to 1K ohm between the
positive input and negative input, and the negative input
connected to the guard terminal. Maximum allowable DC
or DC plus peak AC common mode voltage is 500V.

Slewing Speed 20 in/s, 50 cm/, nominal at 115V line.
Accuracy: ±0.2% of full scale.
Linearity: ±0.1% of full scale.
Resettability: ±0.1% of full scale
Reference Stability: Continuous electronic zener reference with

temperature stability better than 0.002%/degrees C.

Zero Set: Zero may be placed anywhere on the writing area or

electrically off scale up to one full scale from zero index.
Adjustable by a locking ten-turn, high resolution control.

GENERAL
Writing Mechanism: Servo actuated ink pen.
Writing Area: 7 in. X 10 in. (18 cm X 25 cm).
Paper Holddown: Autogrip electric paper hold-down grips

charts 8-1/2 in. X 11 in. or smaller. Special paper is not

required.
Pen Lift: Electric pen lift with provision for remote control.
Power: 115 or 230 V ± 10%, 50 to 60 Hz, approximately 45 W.
Weight: Net, 18 lb (8 kg; shipping, 24 lb (10.9 kg)

1-2

FIGURE 1-4. DIMENSION DRAWING

FIGURE 1-5. ACCESSORIES

1-3

TABLE 1-2. ACCESSORY SUPPLIES

1251-0293 Connector, Male, 24 pin 2110-0063 Fuse, 3/4 Amp (1)

(Mate to J-602)(1)
5080-7979 Pen, Disposable, Red Pack of 3 (1) 2110-0065 Fuse, 3/8 Amp (1)
5080-7980 Pen, Disposable, Blue Pack of 3 (1) 9270-1006 Graph Paper, English Calibrated

(Heavy) (10)

1540-0149 Plastic Box (1)

9270-1007 Graph Paper, English Calibrated

9220-1519 Filler Pad (1) (Light) (10)
5080-3635 Slidewire Lubricant (1) 9270-1023 Graph Paper, Metric Caption-001,

Calibrated (Heavy) (10)

5080-3605 Slidewire Cleaner (1)

9270-1027 Graph Paper, Metric Caption-001,

8120-1378 Power Cord (1) Calibrated (Light) (10)

1-17. MODEL 7563A LOG VOLTMETER/ AMPLIFIER
1-18. The Model 7563A DC Log Voltmeter/Amplifier is

designed to perform two independent operations. As a
voltmeter, usable over a 110 dB input amplitude range,
accurate readings within 1.5 dB over an 80 dB dynamic range
are achieved, and the need for range switching is
unnecessary. As a log amplifier, output signals are
logarithmically related to applied input signals; this solid-state
amplifier permits semilogplotting operations with HP X-Y and
strip-chart recorders, and will operate with most other
recorders and oscilloscopes. Two amplifiers may be used for
log-log records.

1-19. MODEL 17108A TIME BASE
1-20. The 17108A is a self-contained external time base which

will operate on either axis of the 7035B. Any number of
recorders may be driven simultaneously providing the
combined parallel input impedance is 20, 000 ohms or more.
Five sweep speeds are provided from 0.5 to 50 seconds/inch.

1-21. MODEL 10025A STRAIGHT-THROUGH VOLTAGE

PROBE

1-22. The 10025A is a flexible probe with small, pushbutton
pincer jaws which provide a straight-through connection to the
7035B. Maximum input voltage is 600 volts peak. The cable is
terminated in a shielded dual banana plug.

1-23. MODEL 10111A ADAPTER

1-25. MODEL 10002A/B/C/D VOLTAGE DIVIDER PROBE.
1-26. The Voltage Divider Probe (50:1) extends the voltage

range of the 7035B to 1000 volts full scale. The high input
impedance (9 meg of this probe also reduces the loading of the
7035B on the system under test. Accuracy is ± 3%, requires
10111 Adapter, and not usable on the 1 mV/in. and 10 mV/in.
(0.4 mV/cm and 4 mV/cm) ranges. The length of the 10002A
is 5 feet, 10002B is 10 feet, 10002C is 5 feet with a black
identification boot, and the 10002C is 10 feet with a black
identification boot.

1-27. MODEL 11000A CABLE ASSEMBLY
1-28. Dual banana plugs terminate a section of 50-ohm cable,

44 inches overall, plugs for binding posts spaced 3/4 inch.

1-29. TYPICAL PERFORMANCE

1-30. INPUT RESISTANCE VS OFF BALANCE

CHARACTERISTICS

1-31. The input resistance is constant, regardless of off
balance condition except for the 1 mV/in. (0.4 mV/cm) range.
This range, operating in potentiometric mode, draws all the
current flowing in the balance loop through the input circuit.
Referring to Figure 1-6, observe that a linear relationship exists
between the distance off balance and the input resistance, and
because the input resistance at 1% of full scale off balance is
approximately 10 meg ohms, a small off balance condition is
noticeable.

1-24. The 10111A (shielded banana-post-to-female-BNC)
converts banana post inputs on 7035B to shielded BNC inputs
for low-level signal work. This adapter may be used in pairs for
balanced input characteristics.

1-4

1-32. NORMAL MODE NOISE
1-33. This instrument is designed to record dc signals.

Normal mode noise (like frequency) is often superimposed on
the low frequency, which if not eliminated, may produce
unsatisfactory recordings. An excessive amount of noise can

FIGURE 1-6. INPUT RESISTANCE CHARACTERISTICS

saturate the amplifier's output stage causing an increased
dead zone and decreased pen speed. Pen oscillation may
also result if the noise "beats" with the servo system's carrier
frequency. A built-in low pass filter in both axes minimizes the
effects of normal mode noise. The response of this filter is
illustrated in Figure 1-7.

1-34. DYNAMIC RESPONSE
1-35. Figure 1-8 indicates the typical frequency response for a

sinusoidal input. Although the recorder is designed to record
slowly varying dc voltages, ac voltages up to a few Hz can be
recorded.

1-5

FIGURE 1-7. TYPICAL FREQUENCY RESPONSE (INPUT FILTER)

1-6

FIGURE 1-8. TYPICAL DYNAMIC RESPONSE

SECTION II

INSPECTION AND INSTALLATION

2-1. INTRODUCTION

2-2. This section provides information for incoming
inspection, installation, storage, and shipping.

2-3. INCOMING INSPECTION

2-4. MECHANICAL CHECKS
2-5. Inspect the instrument for mechanical damage,

scratches, dents, or other defects. Also check the cushioning
materials for signs of severe stress.

2-6. ELECTRICAL CHECKS
2-7. The electrical performance of the instrument should be

verified upon receipt. Performance checks, suitable for
incoming inspection, are presented in Section V.

2-8. DAMAGE CLAIMS

2-9. If the instrument is damaged in transit, or fails to meet
specifications upon receipt, follow procedures as outlined in
paragraph O-3.

2-10. STORAGE

2-11. If the instrument is to be stored for a period of time, the
disposable pen should be removed and the upper part of the
carriage arm and pen carriage tied to the side of the instrument
to prevent damage during handling. Seal the instrument in a
moisture-proof covering and repackage in a container similar to
the original factory carton.

2-12. SHIPPING

2-13. The following precautions should be taken when
repackaging the recorder:

a. Remove disposable inkpen. Tape a piece of heavy

recording paper to Autogrip table surface.

b. Secure upper end of carriage arm and pen carriage to
side of recorder to prevent movement while in transit with
shipping clamp and pad assembly (Part No. 5080-7834).

c. If recorder is being returned for repair, do not send
power cord or accessory kit.

d. Wrap instrument in heavy paper or plastic and
surround with three to four inches of shock-absorbing material
to cushion and prevent movement inside shipping container.
The container should be sufficiently durable to prevent damage
to instrument during handling.

2-14. RECORDER INSTALLATION

2-15. This recorder requires no physical installation for table
top operation. The accessory wing brackets provided allow
installation on standard 19-inch rack console if desired. To
install, refer to Figure 2-1.

2-16. COOLING

2-17. Cooling is provided by convection. The location or
mounting of the instrument must ensure adequate air
circulation.

2-18. STACKING H-P INSTRUMENTS
2-19. The 7035B is equipped with special feet which allow it to

be stacked on other H-P instruments. Figure 2-2 shows the
7035B stacked on a 7560A and a 3300A. The rear tilt stand
provides easy viewing of the chart.

2-1

FIGURE 2-1. WING BRACKET INSTALLATION

FIGURE 2-2. STACKED CONFIGURATION

2-2

SECTION III

OPERATING INSTRUCTIONS

3-1. OPERATING REQUIREMENTS

3-2. GENERAL
3-3. The basic function of the Model 7035B Recorder is to

produce graphic tracings showing the relationship between two
variable functions. Slowly varying dc signals representing
these functions are applied to the input terminals of the
respective axes of the instrument, and its controls adjusted so
that the resulting graph will cover the desired scope of
operation.

CAUTION Before attempting to operate this

instrument the user should study the
following paragraphs.

3-4. CONTROLS, CONNECTORS, AND INDICATORS
3-5. The front and rear panel controls, connectors, and

indicators are depicted and explained in
Figures 3-1 and 3-2.

3-6. ELECTRICAL REQUIREMENTS

3-7. OPERATING POWER
3-8. The line power supplied to the recorder should be either

115 or 230 volts 10%, 50 to 60 Hz, single phase. A voltage
conversion switch, see Figure 3-2, must be set to correspond
to the available supply voltage. For 115 Vac use a 3/4 amp
fuse. For 230 Vac use a 3/8 amp fuse.

CAUTION Do not directly apply signals in excess of

250 volts on the X-axis or 175 volts on the
Y-axis.

3-11. GROUNDING
3-12. For optimum performance, the third prong of the ac

power cord must be grounded. When operating from
ungrounded power sources, adequate grounding is mandatory.

3-13. RECORDING INPUT CONNECTIONS
3-14. Input terminals for each axis are located on the front

panel adjacent to the corresponding range switches. Front
panel terminals will accept either "banana" plugs or open
wires.

3-15. CONNECTION TECHNIQUES FOR THE GUARD

SHIELD

3-16. Connect the recorder's guard shield in one of the
following ways:

a. To the SOURCE ground when:

1. Operating on low level ranges

2. When ac noise pickup is a problem.

b. To the negative input using the convenient shorting
straps when conditions 1 and 2 do not exist.

3-9. INPUT SIGNALS
3-10. The recorder input terminals (+ and -) must be supplied

with a dc signal on each axis. This signal should be in direct
proportion to the actual function unless a special relationship is
required, such as the logarithmic value of the input voltage.
These signals must vary at a rate within the response
capabilities of the instrument and have amplitudes within its
scale ranges. If an excessive amount of ac noise is present in
the input signals, the response of the recorder may become
sluggish and erratic or oscillatory.

CAUTION Do not leave the guard shield

disconnected or floating. Tighten guard
strap securely.

3-17. MAXIMUM ALLOWABLE SOURCE IMPEDANCE
3-18. No restrictions except on fixed 1mv/in. (0.4 mv/cm)

range. Up to 20k ohm source impedance will not appreciably
alter the recorder's performance. Higher source impedance
will cause an increase in dead zone and a decrease in pen
speed. Values up to approximately 100k may be compensated
for by adjusting the servo amplifier gain adjustment (front
panel).

3-1

FIGURE 3-1. FRONT PANEL CONTROLS (7035B AND 7035B-001 MODELS)

3-2

FIGURE 3-2. REAR PANEL

3-19. OPERATING PRECAUTIONS

3-20. The POWER/SERVO toggle switch apples 115 volts AC
to the recorder. To lower power dissipation and avoid
unnecessary wear to the balancing potentiometers and other
mechanical parts when not actually recording, place the toggle
switch to ON-OFF position.

3-21. When a voltage in excess of the RANGE SETTING is
applied to either set of input terminals, the carriage arm or pen
mount (depending upon the axis used) will be driven rapidly to
full scale and strike the stop. If this condition prevails, the
motor will continue running due to a slip-clutch arrangement,
prolonged running against the stop may cause excessive
motor heating and clutch wear.

3-22. Operation on the most sensitive input range with no
input (input terminals not connected) will result in an inaccurate
zero null. This can be overcome by shunting the input
terminals with a 20k (maximum resistor).

3-23. OPERATING INSTRUCTIONS

3-24. OPERATIONAL CONDITIONS
3-25. Amplitude of the signal must be within the scale range

and vary in level within the response capabilities of the
instrument.

3-26. CONNECT POWER

3-27. Set the power voltage selector switch located on rear of
instrument to either 115 or 230 volts, depending on the
available power source. Connect power cord between the
power receptacle and the power source.

3-28. CONNECT INPUTS
3-29. Connect the signal inputs to each axis through the front

input terminals using open wires or banana connectors, or
through the rear input connectors using the furnished mating
connector. Normally connect the guard input terminal to the
negative input terminal. However, if the shields are to be
driven directly from a remote common mode source, the
jumper is disconnected and a separate wire is connected
between the guard input and the common mode voltage
source. Set RANGE switch to the expected maximum values.

3-30. ENERGIZE RECORDER
3-31. Set the POWER/SERVO toggle switch to ON-ON.

CAUTION Units using photochoppers require a few

minutes of operation to eliminate dark
storage effects. After prolonged storage
of 3 to 6 months, a longer period of run in
may be required. After several days of
storage, a slight improvement in retrace
characteristics may be produced by
several high speed full scale excursions
on each axis.

3-3

3-32. INSTALL PAPER
3-33. Install a sheet of graph paper on the recording platen,

aligning lower and left edges with corresponding paper guides.
Set the CHART switch to HOLD, thereby activating the
AUTOGRIP holddown system. Smooth paper as necessary.

3-34. INSTALL PEN
3-35. The disposable pen is pushed into the notched holder

located on the scale, and twisted clockwise to lock in holder.
See Figure 3-3.

CAUTION The disposable pen incorporates a

precision writing tip. Care must be taken
not to damage this tip during pen
changing or other handling. Writing by
hand on any surface may damage pen tip.
Use pen only in pen holder on recorder.

3-36. ZERO SET
3-37. Connect the input signals to the recorder and adjust

ZERO controls so that the resulting graph will cover the
desired area on the paper.

3-38. LOWER PEN
3-39. Place PEN toggle switch to DOWN position.

FIGURE 3-3. DISPOSABLE PEN INSTALLATION

3-4

SECTION IV

THEORY OF OPERATION

4-1. GENERAL OPERATION DESCRIPTION

4-2. GUARDED INPUTS. The Model 7035B is equipped
with guarded inputs to enable high common mode rejection of
100 db for ac and 130 db for dc voltages. A guard shield
encloses the critical input circuitry except for the balance
potentiometer which is shielded individually from external
coupling. The guard shields are connected to the guard
terminals.

4-3. SERVOMECHANISM. There are two similar, but
independent, self-balancing servomechanisms in the 7035B,
both isolated from ground. In operation, one servomechanism
moves the pen carriage in a vertical direction, the other moves
the entire carriage arm in a horizontal direction in response to
input signals representing data applied to the respective input
terminals. The resulting relative motions of the two
servomechanisms trace cartesian coordinate graphs of the
relationship on the graph paper.

4-4. FIXED AND VERNIER RANGE OPERATION. The
basic dc voltage range of the servo systems is 1 millivolt per
inch (0.4 mv/cm). Operation with greater voltages is obtained
by switching precision resistors into the attenuator circuits.
Each range step may be made continuously variable by
switching in a variable potentiometer. Adjustment of this
control will allow an arbitrary voltage to drive the pen to full
scale. In operation, the initial range setting is based on the
expected maximum voltages.

4-5. BALANCING ACTION. After passing through the
attenuator, the input signal is applied to the balance circuit
where it is cancelled by an internally supplied opposing
voltage. Under "balanced" conditions, there is no error signal
output from the balance circuit and the servo system is at null.
When the input signal changes value, an unbalanced condition
exists. The resulting error signal is applied to a photochopper
which converts the dc to a 60 Hz ac form which is amplified
and applied to the servomotor. Because the motor and
rebalance potentiometer are mechanically coupled, the
balance voltage changes value until the input signal is
cancelled. If the input data is constantly varying at rates within

the capabilities of the instrument, this rebalancing action is
continuous, and the rebalance potentiometers and the pens
are always in a position directly proportional to the amplitude of
the signals at the respective input terminals.

4-6. AUTOGRIP HOLDDOWN. The AUTOGRIP holddown
platen is completely electronic. There are no mechanical or
moving parts. The unit is maintenance free, except for periodic
cleaning of the writing surface.

4-7. CIRCUIT DESCRIPTION

4-8. Schematic symbols refer to the Y-axis unless otherwise
stipulated; however, the X-axis is electrically identical to the Y­axis (with exceptions noted). Reference should be made to the
block diagrams, Figures 4-1 and 4-2, and also the schematics
referenced in each of the following paragraphs.

4-9. RANGE SELECTOR CIRCUIT (See Figure 4-3). Input
terminals of each axis connect to a precision step attenuator
which determines the maximum allowable input voltage. The
resistors forming the attenuator are R-101 through R-105. The
attenuator consists of five precision (± 0.1%) metal film
resistors with good temperature stability. With the selector
switch in the 1 mv/inch (0.4 mv/cm) position, the input voltage
is applied directly to the balance circuit with no attenuation.
The attenuator is also disconnected as a shunt from the input
terminals allowing potentiometric operation in this position.
This provides essentially infinite input impedance when the
recorder is at null. Typical input currents at null on this range
are approximately 10

-10

amps. The full scale balance voltage is
always 7 mv for the Y-axis and 10 mv for the X-axis. For
higher ranges, resistance is inserted in series with the 10,000
ohms (R-109) at the base of the attenuator. On the 1 volt/inch
(0.4 mv/cm) position, and above, the 10,000 ohms is shunted
and no additional series resistance is added.

4-10. RANGE SELECTOR VERNIER CIRCUIT (See
Figure 4-3). The 10 position Range selector has 5 calibrated
positions and 5 positions that provide a vernier sensitivity that
can be adjusted by the user.

4-1

4-2

FIGURE 4-1. BLOCK DIAGRAM

FIGURE 4-2. DETAILED BLOCK DIAGRAM

FIGURE 4-3. RANGE SELECTOR

When the Range selector is set to any of the vernier positions
the resistors used in the fixed positions are switched out and
replaced by a new set of components. The heart of the vernier
circuitry is the variable potentiometer R-108 and the voltage
limiter R-110. When the range selector is set to the first
vernier range, the input signal is applied directly to R-108 and
R-110, and passed through the wiper to the balance circuit.
The other four positions use R-107 or R-106 to attenuate the
signal. In the last two positions the signal from the wiper of R­108 is divided by the string composed of R-111,
R-112, and R-113.

4-13. SLIDEWIRE CIRCUIT (See Figure 4-6.) The Slidewire
Circuit provides the electrical feedback to the Photochopper
and Balance Circuit from the pen carriage or carriage arm.
Resistors R-126 and R-125 are calibration resistors for the
feedback element (slidewire) R-124. Capacitor C-108 passes
unwanted spurious wiper noise to circuit common. Resistor
R-121 limits the voltage applied to the Photochopper and
Balance Circuit.

4-14. DAMPING NETWORK (See Figure 4-6). The phase
lead network (C-107 and R-122) draws a charging current

FIGURE 4-4. INPUT FILTER

4-11. INPUT FILTER (See Figure 4-4.) The input filter is
composed of 3 RC sections. It is a low pass filter providing a
minimum of 20 db attenuation of 60 Hz and a cutoff of 18 db
per octave above 60 Hz to insure smooth plotting from signals
containing extraneous noise. Filter components in the Y axis
are capacitors C-103, C-104, and C-105, with resistors R-114,
R-115, and R-116. The insertion of a filter of this type in each
axis of a two-axis recorder can cause phase shift relative to the
other axis. Since this phase shift can vary from unit to unit
(depending upon component tolerances). R-114 is a variable
resistor that is factory adjusted to equalize the phase shift
between axes. A slight phase shift, however, will be noted
when changing from range to range and when using the range
selector vernier. This phase shift may become very
pronounced on the 1 mv/inch (0.4 mv/cm) range if the input
source impedance is extremely large or extremely small.
Diodes CR-101 and CR-102 are protective devices used to
minimize the possibility of component damage due to an over­voltage at the input terminals.

4-12. ZERO CIRCUIT (See Figure 4-5.) The zero circuit is
composed of R-123 and R-120. The potentiometer R-123
permits the electrical zero to be placed ±1 full scale from
normal zero. Resistor R-120 limits the voltage that is applied
to the Photochopper and Balance Circuit.

FIGURE 4-5. ZERO CIRCUIT

FIGURE 4-6. SLIDEWIRE AND DAMPING CIRCUIT

4-3

whenever a change in output occurs, thus increasing the rate
of appearance of the balance voltage. This phase advance in
the slowly varying error signal causes an "anticipatory"
approach to the balance point, producing damping.

4-15. PHOTOCHOPPER AND BALANCE CIRCUIT (See
Figure 4-7). The Photochopper and Balance Circuit
algebraically sums the outputs of the Input Filter, Zero Circuit,
and Slidewire and Damping Network, and converts the
summation to 50 or 60 Hz form depending on the power line
frequency. Resistor R-119 sums the outputs from the Zero
Circuit and Slidewire and Damping Network. C-106
suppresses spurious voltages that may appear across R-119.
The voltage difference between the potential across R-119 and
the potential from the Input Filter is applied across the
photoconductive cells and their load resistors R-117 and
R-118. The photoconductive cells V-101 and V-102 are
alternately turned on and off by neon bulbs DS-2 and DS-4.
The bulbs are driven as described in Paragraph 4-22 in
synchronism with the power line. This switching action of the
photoconductive cells causes an ac error signal output whose
peak-to-peak amplitude is equal to the dc error signal. The ac
error signal will be either in phase or 180 degrees out of phase,
with respect to the power line, depending on the polarity of the
dc error signal. The direction of rotation of the servo motor is
determined by the relative phase excitation of the winding in
the servo amplifier's output Power Amplifier/Demodulator
Stage and the phase of the ac error signal. This phase
sensing causes the motor to drive potentiometer R-174 in a
direction necessary to seek balance. The total magnitude of
the error signal never exceeds 10 mv on the X-axis or 7 mv on
the Y-axis, and as the instruments must be sensitive to
approximately 0.1% of this voltage, it is apparent that error
signals present are exceedingly small, actually in the low
microvolt region. With this in mind, all input circuitry is carefully
engineered to minimize interference from stray hum pickup and
thermal emfs.

FIGURE 4-7. PHOTOCHOPPER AND

BALANCE CIRCUIT

4-16. DIFFERENTIAL AMPLIFIER (See Figure 4-8). The ac
error signal from the Modulator and Balance Network is applied
to the Gates of Q-101 and Q-102 through coupling capacitors
C-109 and C-110. At time T1; a positive voltage is applied to
the Gate of Q-101, the Source will follow the Gate, and a
positive voltage appears at the Source of Q-102. This positive
voltage at the Source, together with the negative voltage at the
Gate, causes Q-102 to "shut-off" and the Drain becomes more
positive. At time T2, the Source-Gate junction of Q-102 to turn
on and the Drain will become more negative. Components R­130, C-115, R-129, and C-114 are power supply filters.
Capacitors C-112 and C-113 couple the signal from Q-101 to
Q-102. Resistors R-128 and R-132 provide Source loads, and
R-131 provides the Drain load for Q-102. This stage has a
voltage gain of approximately ten.

FIGURE 4-8. DIFFERENTIAL AMPLIFIER

4-17. VOLTAGE AMPLIFIER (See Figure 4-9.) The ac error
signal from the Differential Amplifier is capacitor coupled by C­116 to the base of the first transistor in the voltage amplifier, Q-

103. This high voltage gain section is comprised of three dc
coupled silicon transistors, Q-103, Q-104, and Q-105. This
stage has a minimum ac feedback of 20 db to insure stable
long term performance. The closed loop ac gain is dictated by
resistors R-136 and R-137. R-137 serves to vary the amount
of feedback and act as the servo amplifier gain control. The
electrical location of this control makes it suitable for physically
placing it with the low level dc circuitry and having no danger of
undesired feedback or oscillation. The dc stability of this stage
is achieved by the feedback path from the collector of Q-105.
This feedback path is a low pass filter comprised of resistors
R-138 and R-104, and capacitors C-118 and C-120. It
provides good dc negative feedback, but has adequate ac by­passing so that it has no influence on the overall ac gain of the
amplifier. The several second warm-up time of the recorder is
caused by the time constant of this feedback network. Diode
CR-103 is used to improve the bias voltage conditions on the
input of Q-105 so that R-141 may be a reasonable size. R-139

4-4

is used to pull sufficient quiescent current through Zener diode
CR-104, thereby holding its dynamic impedance at a
reasonable magnitude. Additional amplification is provided by
Q-106 which is capacitor coupled from Q-105 by C-121. The
voltage gain of the Voltage Amplifier is approximately 2000.

FIGURE 4-9. VOLTAGE AMPLIFIER

4-18. POWER AMPLIFIER/DEMODULATOR (See Figure 4-

10). This section can be roughly divided into two sections: the
first section provides the current gain required, and the last
provides both additional current gain and acts as a
demodulator. This stage consists of transistors Q-107, Q-108,
Q-109, and Q-110. Since this is essentially a Class B
operating stage, and the output section is a demodulator
applying half-wave ac to a permanent magnet dc servo motor,
operation of the demodulator section must first be understood
before discussing the entire output stage.

FIGURE 4-10. AMPLIFIER/DEMODULATOR

the line voltage appearing in the secondary of power
transformer T-601. The polarity of Point B is determined by the
error voltage amplifier output and will be either in phase or 180
degrees out of phase with the line as determined by the error
voltage applied to the photochopper.

FIGURE 4-11. MOTOR CONTROL AND

DEMODULATOR

Mode 1 Current flows from T-601, through B-101,
A- CR-108, CR-110, Q-110, R-115, and
B+ through CR-107 back to T-601. The motor

will rotate right.

Mode 2 Current flowing from T-601 is blocked by
A- Q-110. No current will flow, and motor
B- will not rotate.

Mode 3 Current flows from T-601 through CR-106,
A+ CR-110, Q-110, R-155, CR-109, B-101
B+ back to T-601. The motor will rotate left.

Mode 4 Current flowing from T-601 is blocked by
A+ Q-110. No current will flow, and motor
B- will not rotate.

4-20. AC feedback as well as dc feedback is obtained via
R-149 and R-155 to the emitter of the first transistor, Q-107.
The bias current at the input transistor is designed to pull the
output stage very slightly into Class A operation, to the extent
that at null, the voltage across the servo motor is
approximately 1/3 volt rms. Diode CR-105 in the bias string
helps to compensate for the temperature change of Vbe of the
input transistor Q-107 over the temperature range. Resistor R­153, coupling the second and third transistor, limits the current
drain of Q-108 from the 15 volt supply when the output stage is
saturated. Diode CR-110 is used to minimize the power
dissipation in the output transistor Q-110 when the darlington
pair is saturated. Capacitor C-124 is connected directly across
the dc servo motor and serves to suppress RFI caused by the
motor brushes. The voltage gain of this stage is approximately

6.

4-19. The demodulator is shown in simplified form in Figure 4-

11. Power to drive the dc servo motor is taken from a separate
shielded winding on power transformer T-601. The direction of
the motor rotation is determined by the direction of current
through the armature. Control of the motor current is provided
by the darlington pair comprised of transistors Q-109, and Q­110, operating essentially Class B. The four modes of
operation of the demodulator are determined by the relative
phasing of the voltage at Points A and B. Point A is excited by

4-21. POWER AND REFERENCE SUPPLY (See Figure
4-12). The reference voltage for each axis is independents
derived from a Zener controlled dc power supply normally 9
volts. The temperature stability of this supply is better than

0.002% per degree C. This supply also furnished the voltage
for the servo amplifier's first three stages. Since the servo
amplifier input circuit

4-5

combination is floated free of ground at the power transformer,
the reference supply serves several purposes: it not only
furnishes the stable voltage for the balance circuit, but also
furnishes all the power requirements for the servo amplifier
with the exception of the Power Transformer T-601 furnishes
this power from a shielded secondary through rectifying diodes
CR-115 and CR-116 into a peak filter C-125. Two shunt
supplies in series furnish 15 volts for the amplifier's power
stages and 9 volts for the input stages and balance circuit. An
identical but reversed supply furnishes the -9 volts for the zero
circuit.

FIGURE 4-12. POWER AND REFERENCE SUPPLY

4-22. NEON DRIVER (See Figure 4-13.) The power supply for
the neon bulbs that actuate the photochopper's photo cells is
basically a voltage clamp-in circuit comprised of capacitors
C-301, C-302 and diodes CR-301, CR-302. On alternate half­cycles, diode CR-301 conducts causing the full power line
voltage to be placed across capacitor C-301. This essentially
doubles the peak value available to ignite the neon bulbs.
Since high brightness neon bulbs are used to efficiently
operate the photo cells, and since the firing voltage of a high
brightness neon bulb prior to aging may vary greatly, this
voltage doubler eliminates the necessity for aged bulbs by
providing a maximum voltage that will always exceed the
fluctuations of the required firing voltage.

4-23. AUTOGRIP POWER SUPPLY (See Figure 4-14.) The
Autogrip power supply is also located on the amplifier printed
circuit board. The power is obtained from the high voltage
secondary winding on the main power transformer T-601 and
the remainder of the supply is composed of resistors R501
through R505, diodes CR501 through 504, and dual capacitors
C501 and C502. Resistor R501 serves as a current limiter and
capacitor C501 and C502, as well as diodes CR501 through
CR504 form a power supply that places a dc voltage between
the grids of the Autogrip table that is equal to + 380V ± 10%
and -380V ± 10% referenced to ground. Switch S501 is used
to deenergize the Autogrip. A contact closure in the switch
grounds the input voltage to the quadrupler rectifier circuit,
causing the dc voltage on the Autogrip table to go to zero, thus
making the holddown inoperative.

FIGURE 4-14. AUTOGRIP POWER SUPPLY

4-24. PEN DROP SUPPLY (See Figure 4-15.) The power
supply for the electric pen lift consists of a low voltage winding
on T-601, diode CR-401, resistor R-401 and capacitor C-402.
With switch S-401 open, C-402 charges to the peak dc voltage
of the supply. When S-401 is closed, the capacitor discharges
through the pen solenoid, causing a large peak voltage to be
placed across the solenoid for a short period of time. This
surge increases the pull-in force of the solenoid while the
resistor R-401 provides a lower maintained current after the
capacitor has partially discharged. C-401 suppresses switch
arcing.

FIGURE 4-13. NEON DRIVER

4-6

FIGURE 4-15. PEN DROP SUPPLY

SECTION V

MAINTENANCE, PERFORMANCE CHECKS, AND ADJUSTMENTS

5-1. INTRODUCTION

5-2. This section provides information for maintenance,
performance testing, functional checks, and adjustments of the
7035B X-Y Recorder. Maintenance procedures, tests, and
adjustments will ensure that the instrument conforms to
specifications. Functional checks maintain the instrument in an
operational condition. If the instrument fails to meet
specifications, or is inoperable, refer to Section VII,
Troubleshooting.

5-3. PREVENTIVE MAINTENANCE

5-4. GENERAL
5-5. The instrument must be maintained properly for

accurate, trouble-free operation. This requires periodic
lubrication, performance checks, and visual and electrical
checks. In accordance with good maintenance procedures for
all precision measuring instruments, Hewlett-Packard
recorders should be protected from dust. Cover the instrument
when not in use.

5-6. ENVIRONMENTAL OPERATION
5-7. This instrument is designed to operate over an ambient

temperature range of approximately 0°C to 55°C. Operation
under other conditions will produce inaccurate results and may
cause damage to the recorder. In areas with high humidity,
graph paper may become distorted, affecting the accuracy of
the grid lines. The area of operation should also be as free as
possible of air contamination (soot, smoke, fumes, etc).
Excessive air contamination will require more frequent
cleaning.

5-8. CLEANING

b. In accessible areas and where there is only dust
accumulation, cleaning can be accomplished with an air gun.
In more accessible areas and where the air gun will not
remove dirt, dust, or ink, accumulations should be removed
with a sponge or cloth saturated in plain soap and warm water,
then wiped dry.

c. Every eighteen to twenty-four months, gears should
be cleaned thoroughly with a solvent and relubricated. Do not
use soap or water on these components.

d. The following method is recommended for cleaning
Autogrip table. Dust and other accumulation of foreign films on
the table surface will lower the paper holding force. The film
may be removed and the table holding ability restored by using
the cleaning procedure. If strong chemicals, abrasives, or too
much water is used, the table may be permanently damaged.
To clean:

1. Remove pen and paper from recorder.

2. Select a mild liquid soap. Do not use products

with abrasive or corrosive chemicals.

3. Use soft cloth that will not scratch the surface but

will absorb water.

4. Saturate the cloth in warm, soapy water. Wring

cloth until majority of water has been removed.

5. Wipe table surface with damp cloth until Autogrip

table is clean.

CAUTION Never let water stand on Autogrip

surface. It may permanently damage the
table.

5-9. Thorough cleaning should be performed periodically.
Intervals are determined by type of operation, local air
contamination, and climatic conditions. Generally, under
normal use and conditions, cleaning intervals should be nine to
twelve months. Cleaning routine should include the following:

a. Remove platen and bottom cover. See paragraph

5-18.

6. Wipe any moisture from surface.

7. Allow a few minutes to dry before recording.

CAUTION Do not use solvents or silicone-based

cleaners of any type on the Autogrip
platen.

5-1

5-10. POTENTIOMETER CLEANING
5-11. Irregular or "jumpy" plots produced by smooth signals

on a properly adjusted recorder may indicate worn or dirty
balance potentiometers or wipers. To clean the
potentiometer., spray the potentiometer along its entire length
with Slidewire Cleaner (Part No. 5080-3605). Rapidly move
the carriage arm or pen carriage several full scale excursions.
Spray the wiper directly with Slideware Cleaner. Thoroughly
saturate a Kimwipe (Kimberly-Clark Type 900-S) or a cotton
swab with Slidewire Cleaner. Rub the potentiometer (wire
mandrel and return strip) along its entire length, using the
moistened tissue or swab (see Figure 5-1). Note any
discoloration of the tissue or swab after rubbing the
potentiometer. Repeat the cleaning procedure until there is no
stain, then clean once more to insure that all contaminants
have been removed. After cleaning, the potentiometer (wire
mandrel and return strip) must be lubricated with the furnished
Slidewire Lubricant (Part No. 5080-3635). This lubrication will
reduce wear and chemical contamination of the balance
potentiometer assembly (see Figure 5-2).

FIGURE 5-2. POTENTIOMETER LUBRICATION

a. Apply a thin film of lubricant on the X and Y gear
drives (including idler gear). Recommended grease is
Aeroshell MIL-G-7118A and 3276A or HP Part Number 6040-

0222.

CAUTION Lubricant must not spill onto the

X-axis drive belt.

FIGURE 5-1. POTENTIOMETER CLEANING

5-12. LUBRICATION
5-13. The Model 7035B is a precision instrument. Gears and

other moving parts have very close tolerances. Lubrication of
gears should be performed sparingly. Over lubrication may
produce more friction than no lubrication. Intervals between
periodic lubrication are determined by the type of operation,
local air contamination, and climatic conditions. Generally,
under normal use and conditions, the recorder should be
lubricated every nine to twelve months. Complete relubrication
should be performed every two years. All ball bearings are
prelubricated by the manufacturer and require no further
lubrication.

5-14. VISUAL LUBRICATION
5-15. During periodic cleaning and lubrication, a planned

visual inspection should be performed. The following steps are
a general approach:

a. Check both the X and Y drive gears for proper
adjustment (a very slight amount of backlash) and any worn or
damaged teeth.

b. Inspect X-axis drive cable pulleys for any binding.

c. Insure that both servo motors are mounted securely.

d. Move pen carriage up and down, listening for
scrapes, grinding noises, etc., while feeling for any binding in
the movement. Repeat this procedure for the carriage arm.

e. Check cables of both axes for fraying or rubbing.

f. A check of components should include inspection for
evidence of overheating, loose connections, cracked circuit
boards, etc.

5-16. MECHANICAL MAINTENANCE

5-17. DISASSEMBLY/ASSEMBLY
5-18. Access to components for maintenance, checks, and

adjustments requires removal of exterior parts

5-2

first, such as panels, covers, etc. To disassemble/assemble,
perform the following steps:

NOTE Before proceeding with disassemble/assemble

procedure, remove disposable pen and ac power
cord.

a. Bottom Cover - Stand recorder on side. Remove 8
No. 6-32 machine screws. Input attenuators, amplifiers,
balance circuit, and power supply are accessible.

b. Interior - For access to circuit side of printed circuit
board, remove 3 No. 8-32 nuts holding control panel frame to
recorder, 3 No. 6-32 screws holding printed circuit board, and 6
front panel knobs. Entire board/frame assembly tilts out. See
Figure 5-3.

FIGURE 5-4. SIDE PANEL REMOVAL

5-19. CARRIAGE ARM REMOVAL
5-20. To remove, perform the following steps.

FIGURE 5-3. TILTING OUT ENTIRE CIRCUIT BOARD

ASSEMBLY

c. Autogrip Table - Place carriage at far right of travel.
Remove 4 No. 8-32 mounting screws. Slide platen toward side
of recorder. Disconnect 2 Autogrip power leads before easing
platen all the way out.

d. Rear Hood - Pull upward and disengage spring clips.

e. Wing Brackets -Remove 2 No. 10-32 machine screws
per bracket. See Figure 2-1.

f. Side Panel -Remove bottom cover. Carefully insert
small, sharp, slot type screwdriver behind upper edge of panel
and gently pry outward. Panel free (see Figure 5-4).
Progressively pull upper edge free, working from one end to
other until panel pops off. To install, hook upper edge of side
panel over top of frame or into groove. Swing lower edge of
panel toward bottom of recorder. Force past outer surface.
Snap into place.

a. Remove rear hood and platen. See paragraph 5-18.
b. Unsnap pen scale at rear and remove from arm. See

Figure 5-5.

c. Remove X-axis slidewire. See paragraph 5-24.

d. Remove 2 shouldered screws at upper end holding
pen carriage arm. Arm lifts off its motor block. See Figure 5-6.
Do not damage wires connecting potentiometer to motor block.
Slide arm toward rear, separating it from lower carriage track.
Small wheel which rides in track is not retained and may fall
off.

e. After reassembling carriage arm, align Y-axis. See
paragraph 5-73.

5-21. PEN CARRIAGE REMOVAL
5-22. The pen carriage may be removed for replacement or

service as follows:

a. Remove carriage arm. See paragraph 5-20.

b. Remove nylon cable from around drive and return
pulleys. Slide carriage forward and over return pulley.

c. After reassembling pen carriage, adjust pen carriage.
See paragraph 5-71.

5-3

FIGURE 5-5. PEN SCALE REMOVAL

FIGURE 5-6. CARRIAGE ARM REMOVAL

FIGURE 5-7. REMOVAL OF X-AXIS REBALANCE

POTENTIOMETER

5-23. POTENTIOMETER REPLACEMENT - X-AXIS
5-24. The mandrel and its mounting channel are an integral

unit, available only as a single item. Install as follows:

a. Remove rear hood and platen. See paragraph 5-18.
b. Remove 2 screws mounting slidewire assembly to

frame. See Figure 5-7.

c. Unsolder 3 wires, noting order of leads connected to

slidewire.

d. More slidewire assembly upwards, being careful not

to damage wiper. See Figure 5-8.

5-4

FIGURE 5-8. X-AXIS WIPER PROTECTION

e. Install new slidewire assembly, Part No. 07035-

80730.
5-25. WIPER REPLACEMENT - X-AXIS
5-26. The wiper is made of a soft metal to absorb wear. It is

located on the pen motor block at the upper end of the carriage
arm. New wiper assemblies should be obtained from the
factory and installed as follows:

CAUTION Damage to the flat mandrel slidewire may

result if other than factory supplied wiper
is used.

a. Remove rear hood and platen. See paragraph 5-18.

5-33. X-AXIS SERVO MOTOR REPLACEMENT

b. Snap pen lift solenoid out of its spring holder and
remove holder and X-axis pointer by removing 1 mounting
screw.

c. Remove wiper assembly mounting screw and install
new wiper, Part No. 5060-4570.

5-27. POTENTIOMETER REPLACEMENT - Y-Axis
5-28. This unit is located in the carriage arm and is part of the

carriage channel. The channel and potentiometer are replaced
as one unit. Replace as follows:

a. Remove rear hood and platen. See paragraph 5-18.

b. Remove carriage arm and X-axis slidewire. See
paragraphs 5-20 and 5-24.

c. Unsolder 3 wires, noting order of leads connected to
slidewire.

d. Install new slidewire assembly, Part No. 07035-

80750.
5-29. WIPER REPLACEMENT - Y-Axis
5-30. The wiper is made of a soft metal to absorb wear. The

wiper is located on the pen block. New wiper assemblies
should be obtained from the factory and installed as follows:

5-34. To remove:

a. Remove rear hood and platen. See paragraph 5-18.
b. Remove 2 No. 4-40 setscrews and slip flywheel off

motor shaft.

c. Stand recorder on side. Remove bottom cover. See

paragraph 5-18.

d. Unsolder 2 wires, noting their polarity. Remove 1

capacitor.

e. Using Phillips screwdriver, remove 2 screws mounting

motor. See Figure 5-9.

CAUTION Damage to the flat mandrel slidewire may

result if other than factory supplied wiper
is used.

a. Remove rear hood and platen. See paragraph 5-18.

b. Remove pen scale. See paragraph 5-20.

c. Remove X-axis potentiometer. See paragraph 5-24.

d. Remove pen carriage arm. See paragraph 5-22.

e. Remove wiper assembly from pen block by
unscrewing 1 0-80 screw and nut.

f. Install new wiper, Part No. 5080-7706.

g. After reassembling pen carriage, adjust pen carriage.
See paragraph 5-71.

5-31. SERVO MOTOR MAINTENANCE
5-32. The magnetic field strength of the servo motor will

weaken if the rotor is removed from within the magnet. Upon
reassembly, it will be impossible for the motor to return to
specified performance. Therefore, only servo motor
replacement and brush replacement or adjustment are
recommended.

FIGURE 5-9. SERVO MOTOR MAINTENANCE AND

BACKLASH ADJUSTMENTS

f. Tilt motor so that drive belt can be disengaged.

Remove motor.

g. Reverse above steps to install.

h. Adjust X-axis drive belt. See paragraph 5-77.
5-35. Y-AXIS SERVO MOTOR REPLACEMENT
5-36. To remove:

a. Remove rear hood. See paragraph 5-18.

b. Move pen carriage to extreme left hand position.

c. Stand recorder on right side. Remove bottom cover.
See paragraph 5-18.

5-5

d. From bottom of recorder, unsolder 2 wires, noting

their polarity. Remove 1 capacitor.

NOTE: If either servo motor was removed, install per

paragraph 5-34 or 5-36.

e. Remove 2 screws and clamps mounting motor.

Withdraw motor from block.

f. Reverse above steps to install.

g. Adjust Y-axis drive gears. See paragraph 5-69.
5-37. BRUSH REPLACEMENT
5-38. If it appears the brushes must be replaced, perform the

following steps without removing the motor from the recorder.

a. Unsolder two motor leads and remove two solder lug
mounting screws. (Note the polarity of the lugs and mark so
that when reassembling a phase reversal will be avoided.)

b. Unhook brush spring from under tab on each lug.
Pivot brush springs outward and pull brushes out of their holes.
Remove solder lugs and brushes.

c. Remove two screws retaining end bell.

d. Carefully pull rear end bell and bearing assembly from
rotor, while holding magnet in place against front end bell.
Make sure rotor remains in place inside motor as rear end bell
is removed. If necessary, push rear end of shaft with a pencil
point or similar object as rear end bell and bearing are
removed.

5-39. CORRECTION OF STICKING MOTOR BRUSHES
5-40. The most common cause of a sticking motor brush is an

interference between the motor body and the brush lead wire,
preventing the brush from moving downward. By carefully
repositioning the lead, the brush can be freed. Other possible
causes of a sticking brush are burrs in its holes or an
accumulation of foreign matter. I either of these is the cause,
the motor will have to be removed and cleaned or replaced.

5-41. Y-AXIS RESTRINGING
5-42. To restring, using Y-axis cable assembly, Part No.

07035-61420, perform the following procedure:

a. Remove rear hood and platen. See paragraph 5-18.
b. Remove carriage arm and pen block. See

paragraphs 5-20 and 5-22.

c. Attach free end of tension spring to the hook on pen
block. Insert knotted end of new nylon cord assembly in
groove of pen block. See Figure 5-10.

e. Blow or brush dust from magnet, rotor, and rear end
bell brush holes. Use an air hose if possible. Be careful not to
lose ball bearing or bearing spacer shims.

f. Replace rear end bell and bearing assembly. Secure

with two long screws removed earlier.

g. Replace two solder lugs in end bell slots and secure
with screws.

h. Install each brush in brush hole making certain that
arc on bottom of brush matches curvature of commutator.
Pigtail leads should rise straight up out of brush hole until
brush springs have been installed. Use a pencil point to adjust
pigtail and to push brush all the way down into brush hole.

i. Swing brush springs back to their original position,
engaging slots on top of brushes and hook rear end of each
spring under tab on terminal lug. Fold pigtails into top of spring
slot so they are below surface of end bell. Solder motor wires
to the correct lugs.

j. Operate recorder. If pen drives into stops instead of
seeking null, motor polarity has been inadvertently reversed.
Reconnect motor wires to opposite terminal lugs.

k. Run recorder through complete performance check.
If brushes are not seating well, apply a 0.3 Hz sine wave to
recorder, adjust to 85% of full scale travel, and let recorder run
for an hour.

FIGURE 5-10. NYLON CABLE (ATTACHMENT TO PEN

BLOCK)

d. Slide pen block into carriage arm. Ensure cable is
between pen block and slidewire. Care should be taken not to
damage wiper.

e. Loop cord around upper and lower pulleys.

f. Reassemble.

g. Make cable tension check. See paragraph 5-65.
5-43. X-AXIS RESTRINGING
5-44. To restring, using X-axis cable assembly, Part No. 5080-

3627, perform the following procedure:

a. Remove rear hood and platen. See paragraph 5-18.

b. Position carriage arm at convenient location and
fasten securely with tape to prevent movement. Remove old
cable.

c. Make small loop in one end of cable and clinch with
cable crimp. See Figure 5-11.

5-6

FIGURE 5-11. RESTRINGING DIAGRAM

d. Attach loop to center of cable yoke (Point A). Route
cable around right-hand side of cable yoke (Point B), and pass
it in front of cable yoke to pulley C. Continue around pulley C
in a counterclockwise direction to sheave D. Make one
counterclockwise turn around sheave D.

e. If recorder is equipped with a retransmitting
potentiometer (Option 003) follow this step. If not, go on to
step f. From sheave D start cable in center of sheave E. Make
two turns in a counterclockwise direction, passing cable
beneath itself after each turn. After second turn run cable
through the slot on bottom edge of sheave to hole in the
sheave. Run cable through the hole, and under screw and
washer on top of sheave. Tighten screw. Pass cable through
slot on top edge of sheave. Continue around sheave two more
turns in a counterclockwise direction, passing each turn
beneath itself, and continue to pulley F.

f. Pull cable around pulley F in counterclockwise
direction, pass it in front and around left-hand edge of cable
yoke (Point G) and pass it to screw (Point H) on Y motor block.

g. Pass cable around screw (Point H) in clockwise
direction. Firmly pull on cable (to keep the cable taut), and
tighten screw.

NOTE: There is a nut on the bottom of Nut H. Make sure

this is tight.

i. Clip off the excess wire.

5-45. ELECTRICAL MAINTENANCE

5-46. REQUIREMENTS
5-47. The Model 7035B requires minimum electrical

maintenance. It is carefully aligned during manufacture.
However, if the recorder ever requires alignment, specific
adjustment procedures are detailed in this section. Section VII,
Troubleshooting, contains additional material.

5-48. PERFORMANCE TESTS

5-49. CRITERIA
5-50. This instrument should meet the following Hewlett-

Packard performance standards to assure operation within
specifications. If this instrument fails to meet the following test
specifications, refer to adjustment procedures within this
section or Section VI, Troubleshooting.

5-51. TEST EQUIPMENT
5-52. The instruments and accessories required for

completing performance tests are listed in Table 5-1.

h. Check cable tension as described in paragraph 5-75.

5-7

TABLE 5-1. RECOMMENDED TEST EQUIPMENT

a. Connect DC Standard to X input terminals.

1. HP MODEL 740B DC VOLTAGE STANDARD

2. HP MODEL 3310A FUNCTION GENERATOR

3. HP MODEL 410C or 427A DC VOLTMETER

4. HP MODEL 202A LOW FREQUENCY FUNCTION

GENERATOR
5-53. INITIAL CHECKS
5-54. To perform initial performance checks:

a. Set 115/230 selector switch to appropriate power

source.

b. Connect power cable.
c. Install pen and paper.
d. Position POWER/SERVO toggle switch to ON-ON.
e. Position CHART toggle switch to HOLD. Paper is

held down securely.

f. Position PEN toggle switch to DOWN.

g. Connect DC Standard to high and low (+ and -) Y-axis

inputs.

b. Place pen at exactly zero on X-axis and at 3.5 in. (9

cm) on Y-axis.

c. Apply 1 volt to X input terminals.
d. Pen should stop at 10 inches (25 cm) within ±0.020

in. (0.5 mm).

e. If pen does not stop within tolerance, adjust

calibration control (R226).

f. Reduce voltage applied in steps of 0.1V at each step.

g. After each step, pen should stop at 1 in. (2 cm)

intervals within 0.020 in. (0.5 mm).
5-57. Y-AXIS SLEWING SPEED

a. Hook up recorder as shown in Figure 5-12.

h. Apply positive dc voltage. Pen moves upscale.

i. Return pen to zero position.
j. Disconnect DC Standard from Y inputs. Connect to X

inputs.

k. Apply positive dc voltage. Pen moves across

recording area.
5-55. Y-AXIS ACCURACY AND LINEARITY

a. Connect DC Standard to Y input terminals.
b. Place pen at exactly zero on Y-axis and at 5 inches

(12. 5 cm) on X-axis.

c. Apply 0.7 volt to Y input terminals.
d. Pen should stop at 7 inches (18 cm) within ±0.014 in.

(0.34 mm).

e. If pen does not stop within tolerance, adjust

calibration control (R-126).

f. Reduce voltage applied in steps of 0.1V at each step.

g. After each step, pen should stop at 1 in. (2 cm)

intervals within 0.014 in. (0.34 mm).
5-56. X-AXIS ACCURACY AND LINEARITY

5-8

FIGURE 5-12. Y-AXIS SLEWING SPEED TEST SETUP

b. Set Function Generator to 0.5 Hz and triangular wave

output with peak-to-peak output of 1V.

c. Position pen to bottom grid line.
d. Apply 0.7 VDC to Y input at beginning of an X

excursion.

e. Measurement is shown in Figure 5-13.

5-58. X-AXIS SLEWING SPEED

a. Hook up recorder as shown in Figure 5-14.
b. Set Function Generator to 0.715 Hz and a triangular

wave output with peak-to-peak output of 0.7V.

c. Position pen to bottom grid line.

FIGURE 5-13. SLEWING SPEED DETERMINATION

a. Set RANGE switch to 1 mV/in. (0.4 mV/cm). Connect
input terminals with short between high (+) and guard, and 1K
Resistor between low (-) and guard.

b. Connect DC Standard between Y guard terminal and
ground.

c. Set DC Standard to 500 volts.

d. Pen will overshoot and settle to a level not It exceed

0.16 inch (4.0 mm) from initial position on chart.

e. Repeat at all fixed attenuator positions for Y inputs.

f. Repeat test for X-axis. Pen deflection is same.

CAUTION Before removing input leads, reduce

signal to zero.

5-61. AC REJECTION

a. Set RANGE switch to 1 mV/in. (0.4 mV/cm). Connect
the 1k ohm resistor between the high (+) and low (-) terminals,
and a short between the low (-) and guard terminals.

b. Pen deflection shall not exceed 0.1 inch (2.54 mm)
with pen in any position on paper.

c. Set Function Generator to 10 V peak-to-peak sine
wave and sweep frequency ±3 Hz around line frequency.

FIGURE 5-14. X-AXIS SLEWING SPEED TEST SETUP

d. Apply 1 VDC to X input at beginning of a Y excursion.

e. Measurement is shown in Figure 5-13.
5-59. COMMON MODE REJECTION
5-60. DC REJECTION

d. Pen deflection shall not exceed 0.2 in. (5 mm) with

pen at any position on paper.

e. Repeat at all fixed attenuator positions for Y inputs.

f. Repeat test for X-axis. Pen deflection is same.

5-62. MECHANICAL ADJUSTMENTS

5-63. PROCEDURE
5-64. Any adjustment to the instrument is deemed necessary

only when it is determined the instrument is out of adjustment
per specifications, but not malfunctioning due to component
failure.

5-65. Y-AXIS DRIVE STRING TENSION CHECK/

ADJUSTMENT

5-66. The Y cable tension may be verified by measuring the
force required to move the pen carriage downscale while the
motor is locked. This required force shall be between the limits
of 6 ounces and 12 ounces. To perform the procedure, it is
necessary to first remove be rear hood and platen. The
procedure is shown in Figure 5-15.

5-67. If the string tension is not correct, the string must be
lengthened or shortened to attain the desired tension. This
can be accomplished by removing the pen block from the pen
arm and retying the knot on the end of the string. See
paragraph 5-42.

5-9

FIGURE 5-15. Y-AXIS DRIVE STRING

TENSION CHECK

5-68. Y GEAR TRAIN BACKLASH ADJUSTMENT
5-69. The Y-axis drive system alignment requires adjusting

two gears. These two gears must be adjusted for backlash in
proper sequence for best results.

a. Remove rear hood. See paragraph 5-18.

b. Remove rear side panel. See paragraph 5-18.

c. Snap pen lift solenoid out of its holder.

d. Move pen carriage to left until the gear adjusting
setscrew at rear of pen motor block is in line with large access
hole in rear wall. See Figure 5-16.

e. Loosen gear locking screw in upper left corner of pen
motor block (Figure 5-17).

f. Lightly push idler gear toward pen drive, and turn
adjusting screw in or out to attain minimum backlash between
two set gears.

FIGURE 5-16. Y-AXIS BACKLASH ADJUSTMENT (GEAR

ADJUSTING SCREW)

g. Tighten gear locking screw.
h. Move pen carriage to extreme left-hand position and

stand recorder on its right side.

i. Remove bottom cover.

j. Slightly loosen two motor clamping screws from
bottom of the recorder. Rotate motor slightly, first in one
direction and then in the other, while moving pen gear back
and forth until motor pinion rotates freely with minimum
backlash. This procedure varies mesh between motor pinion
and pen drive gear due to an eccentric mounting shoulder. A
slight amount of backlash is desirable for optimum operation
(See Figure 5-18).

5-10

FIGURE 5-17. Y-AXIS BACKLASH ADJUSTMENT (GEAR

LOCKING SCREW)

k. Tighten motor clamping screws and recheck for

optimum backlash.

l. Reassemble recorder.
5-70. Y-AXIS PEN CARRIAGE ADJUSTMENT
5-71. The pen block rolls in the carriage arm on four plastic

rollers. To adjust these rollers:

a. Move pen block to bottom of arm so 2-56 Bristol
setscrew in block is aligned with notch in side of arm, see
Figure 5-18.

FIGURE 5-18. Y-AXIS PEN CARRIAGE ADJUSTMENT

b. Adjust setscrew to minimize sideplay of block with

arm (Adjustment wrench provided in Accessory kit.)

c. Move pen block to upper end of arm so as to align
upper setscrew with notch at upper end of arm. Repeat
operation.

NOTE: Care should be taken not to adjust out all

sideplay. This will cause mechanical drag and
result in a poor trace.

5-72. Y-AXIS ALIGNMENT
5-73. If a vertical pen trace deviates from perpendicular when

compared with correctly aligned paper grids, the carriage arm
should be adjusted as follows:

a. Remove rear hood. See paragraph 5-18.

b. Remove pen scale. See paragraph 5-20.

c. Remove X-axis slidewire to prevent accidental
damage. See paragraph 5-24.

d. Replace pen in notched holder.

e. Partially loosen 2 shouldered screws, A and B, at
upper end of arm, see Figure 5-19.

f. Manually move arm in indicated direction until pen
draws a line exactly parallel to vertical grid lines on graph
paper.

g. Retighten both screws. Recheck alignment. Remove

pen.

h. Reassemble.

5-74. X-AXIS CABLE TENSION CHECK/ADJUSTMENT
5-75. The X cable tension should be verified by measuring the

force required to displace it at a given distance. With the arm
at the extreme right, the force required to displace (in a plane
parallel to the control panel and in a direction toward the front
of the unit) the center of the longest span of the cable 1/4 inch
past the vertical wall of the motor assembly trough shall be
between the limits of 15 ounces and 32 ounces. See Figure
5-20. Some adjustment is possible by loosening and
repositioning idler pulleys.

5-76. If adjustment is not possible by moving pulleys, a new
cable must be installed, making sure that at time of installation
the tension is correct. See paragraph 5-44.

5-77. X-AXIS DRIVE BELT TENSION CHECK/

ADJUSTMENT

5-78. The X-axis drive belt tension may be verified by
measuring the force required to move the carriage arm to the
right while the drive sheave is locked. This required force shall
be between the limits of 20 ounces and 30 ounces. See Figure
5-21.

5-79. If adjustment is necessary:

a. Remove platen and bottom cover. See paragraph

5-18.

b. Slightly loosen two motor mounting screws from

bottom of recorder. See Figure 5-22.

c. Rotate motor in indicated direction until desired

tension attained.

d. Check belt tension. If force not between the limits of

20 and 30 ounces, repeat above steps.

e. Retighten motor mounting screws.

f. Reassemble.
5-80. X-AXIS DRIVE BELT REPLACEMENT
5-81. To replace the X-Axis drive belt proceed as follows:

a. Remove rear hood, platen, and bottom cover. See

paragraph 5-18.

b. Loosen two motor mounting screws from bottom of
recorder (see Figure 5-22) and rotate motor until belt is as
loose as possible.

c. Remove two clamps holding pulley assembly and
carefully lift assembly outward. Old belt will slip off. Remove
from around motor.

d. Install new belt, Part No. 1500-0043.

e. Replace pulley assembly and clamps.

f. Adjust belt tension. See paragraph 5-77.

g. Reassemble.

5-11

FIGURE 5-19. Y-AXIS ALIGNMENT

FIGURE 5-20. X-AXIS CABLE TENSION CHECK

5-12

FIGURE 5-21. X-AXIS DRIVE BELT TENSION CHECK

FIGURE 5-22. DRIVE TRAIN ADJUSTMENTS

5-82. X GEAR TRAIN BACKLASH ADJUSTMENT
5-83. Backlash of the gear drive system may be adjusted as

follows:

a. Remove rear hood, platen, and bottom cover. See

paragraph 5-18.

b. Using a 1/4 inch nut driver, slightly loosen two clamps
which mount X-axis pulley and pinion on underside of chassis.
See Figure 5-22.

CAUTION Do not overtighten this adjustment. This

could result in bearing damage or failure.

5-86. X-AXIS DRIVE TRAIN BEARING REPLACEMENT
5-87. To replace any of the X-axis drive bearings, the X-axis

drive cable must be partially or completely removed,
depending on which bearing is affected. See Figure 5-23.

5-88. PULLEY BEARING REPLACEMENT. To replace either
pulley bearing, proceed as follows:

a. Remove rear hood and platen. See paragraph 5-18.
b. Move pen carriage to its extreme position away from

affected pulley.

c. Apply masking tape to remaining pulley and drive
sheave so as to prevent cable from slipping off when tension is
removed.

d. Remove bottom cover. See paragraph 5-18.

e. While holing pulley nut on bottom side of recorder,
remove No. 6-32 screw mounting pulley. Remove pulley and
its mounting stud.

f. Press out defective bearing. Replace with new

bearing, Part No. 1410-0215.

g. Reassemble, making sure pulley is reinstalled with flat
side up, as is other pulley.

5-89. DRIVE SHEAVE BEARING REPLACEMENT. To
replace, proceed as follows:

a. Remove rear hood and platen. See paragraph 5-18.

c. Using thumb and fingers, rotate housing first in one
direction and then other, while moving pen arm from side to
side, until gear rotates freely with minimum backlash. A slight
amount of backlash is desirable for optimum operation.

d. Tighten mounting clamps and recheck for minimum
backlash. If minimum backlash not attained, repeat above
steps.

e. Reassemble.
5-84. X-AXIS TRACK BEARING ADJUSTMENT
5-85. Adjustment of the X-axis track bearing is accomplished

as follows:

a. Remove rear hood, rear side panel, and bottom
cover. See paragraph 5-18.

b. Move pen arm until it is opposite access slot.

c. Using Phillips Pozidrive screwdriver, turn bearing
adjusting screw until a slight amount of clearance is detectable
between the five ball bearing rollers and track rod.

d. Reassemble.

b. Remove X-axis drive cable.
c. Remove retaining ring and slip sheave/gear assembly

upwards and off stud.

d. Separate gear from sheave by removing 2 No. 2-56

flat head mounting screws with a Phillips screwdriver.

e. Push bearings (2) out bottom of sheave and replace

with new bearing(s), Part No. 1410-0277.

f. Restring X-axis. See paragraph 5-44.

g. Reassemble.

5-90. BELT PULLEY BEARING REPLACEMENT. Replace as
follows:

a. Remove rear hood, platen, and bottom cover. See

paragraph 5-18.

b. Loosen two motor clamping screws (Figure 5-22).

Rotate motor until belt is as loose as possible.

5-13

FIGURE 5-23. X-AXIS GEAR TRAIN BEARINGS

c. Remove two clamps holding pulley housing. Slip
drive belt off pulley and pull assembly (A) out of its hold from
bottom. See Figure 5-23.

d. Remove retaining ring from belt pulley shaft. Slide
shaft out of housing.

e. Remove defective bearing(s) and replace with new
bearing, Part No. 1410-0277.

f. Reinstall pulley. Adjust belt tension. See paragraph

5-76.

g. Reassemble.
5-91. ELECTRICAL ADJUSTMENTS
5-92. GAIN ADJUSTMENT
5-93. The gain potentiometers are labeled GAIN on the control

panel and are adjustable wit a screwdriver. If gain in X or Y
channel is insufficient (poor retrace) adjust as follows:

a. Connect low frequency Function Generator to X and
Y input terminals. Set up for triangular output wave of 500 mV
pk/pk at 0.1 Hz.

b. Set X RANGE switch to 100 mV/in. (40 mV/cm), Y
RANGE switch to 1V/in. (0.4V/cm).

c. Turn on recorder.
d. Adjust R237 until minimum retrace error exists.
e. Pen speed should not exceed 1 in./sec (0.4 cm/sec).

f. Similarly, set Y RANGE switch to 100 mV/in. (40

mV/cm), X RANGE switch to 1V/in. (0.4V/cm).

g. Adjust R137 for optimum retrace at 1 in./sec (0.4

cm/sec).
5-94. CALIBRATION ADJUSTMENT
5-95. If recalibration adjustment is required to accommodate

various graph papers, etc., perform the following procedure:

a. Connect DC Standard to X input terminals.
b. Set RANGE switch to 100 mV/in. (40 mV/cm).
c. Adjust ZERO controls to position pen exactly at zero.
d. Apply 1.0 Vdc (1.25V) signal to X input terminals.
e. Adjust R226 to position pen to full scale.

5-14

f. Remove signal from X input terminals.
g. Apply 0.7 Vdc (0.9 Vdc) to Y input terminals.
h. Adjust R126 to position pen to full scale.

i. In the event full scale cannot be reached by using

calibration controls, check electronic reference for output of 9.0
volts ±5%.

5-96. PHASE SHIFT ADJUSTMENT
5-97. Assuming both X and Y axes have been adjusted by

means of the retrace curves described in paragraph 5-91, the
attenuator switches may be set to identical values in both X
and Y to produce a straight line of 45 degree angle. If the
retrace test made on X and Y demonstrates zero trace, the gap
which appears in the 45 degree retrace line will be due to a
phase difference or time lag between the two recording axes.
Phase adjust is accomplished by adjusting R114. Access to
R114 is obtained by removing bottom cover. See
paragraph 5-18 and Figure 5-24.

FIGURE 5-24. CIRCUIT BOARD ADJUSTMENT

5-15/5-16(blank)

SECTION VI

PARTS LIST

6-1. INTRODUCTION

6-2. This section contains complete information on parts list
presented in an alphanumerical and numerical order. The
procedure for ordering replacement parts is also contained in
this section.

6-3. PARTS LIST

6-4. ALPHANUMERICAL TABLE
6-5. Table 6-1 lists parts in alphanumerical order by schematic

circuit symbols, H-P number, quantity, five digit manufacturer's
code, and manufacturer's part number.

6-6. MISCELLANEOUS PARTS
6-7. Table 6-2 lists miscellaneous items not related to those

parts in Table 6-1. They will be listed by part number,
description, and manufacturer.

6-8. RECOMMENDED SPARES
6-9. Table 6-3 lists all components with mortality experience.

Recommended quantities to stock for maintaining the
instrument for a one-year period are specified in the quantity
column.

6-10. CODE LIST OF MANUFACTURERS
6-11. Table 6-4 lists the five-digit code number assigned to a

specific manufacturer. This table is a cross-reference to Table
6-1 in that the five-digit number listed in Table 6-1 is identified
by name in this table.

6-12. ILLUSTRATED PARTS BREAKDOWN.
6-13. Additional parts information is included to identify other

subassemblies. This information is presented as a parts
breakdown illustration with an accompanying legend. See
Figures 6-1 and 6-2.

6-1

Reference Mfr

Designation

A1 X-Y RECORDER
B101 5080-3696 1 Y-AXIS SERVO MOTOR 28480 5080-3696
B201 5080-3695 1 X-AXIS SERVO MOTOR 28480 5080-3695
C101 0160-0819 4 C:FXD MY 0 047 UF 10% 600VDCW 14655 WMF-6S47
C102 0160-0819 C:FXD MY 0 047 UF 10% 600VDCW 14655 WMF-6S47
C103 0180-0291 10 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C104 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C105 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C106 0150-0121 2 C:FXD CER 0.1 UF +80-20% 50VDCW 56289 5C50BIS-CML
C107 NOT USED
C108 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C109 0160-0161 4 C:FXD MY 0.01 UF 10% 200VDCW 56289 192P10392-PTS
C110 0160-0161 C:FXD MY 0.01 UF 10% 200VDCW 56289 192P10392-PTS
C111 NOT USED
C112 0180-0374 6 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C113 0180-0374 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C114 0180-0137 4 C:FXD ELECT 100 UF 20% 10VDCW 56289 150D107X0010R2-DYS
C115 0180-0137 C:FXD ELECT 100 UF 20% 10VDCW 56289 150D107X0010R2-DYS
C116 0160-0137 4 C:FXD CER 0.33 UF 20% 25VDCW 56289 5C10A7 CML
C117 0160-0818 6 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C118 0180-0374 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C119 0160-0818 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C120 0160-0818 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C121 0160-0174 2 C:FXD CER 0.47 UF + 80-20% 25VDCW 56289 5C11B7S-CML
C122 0160-0137 C:FXD CER 0.33 UF 20% 25VDCW 56289 5C10A7 CML
C123 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C124 0160-2105 3 C:FXD CER 0.001 UF +100-0% 1000VDCW 72982 8015V-102P
C125 0180-0094 4 C:FXD ELECT 100 UF + 75-10% 25VDCW 56289 30D107G025DD2-DSM
C126 0180-0094 C:FXD ELECT 100 UF + 75-10% 25VDCW 56289 30D107G025DD2-DSM
C201 0160-0819 C:FXD MY 0 047 UF 10% 600VDCW 14655 WMF-6S47
C202 0160-0819 C:FXD MY 0 047 UF 10% 600VDCW 14655 WMF-6S47
C203 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C204 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C205 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C206 0150-0121 C:FXD CER 0.1 UF +80-20% 50VDCW 56289 5C50BIS-CML
C207 NOT USED
C208 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C209 0160-0161 C:FXD MY 0.01 UF 10% 200VDCW 56289 192P10392-PTS
C210 0160-0161 C:FXD MY 0.01 UF 10% 200VDCW 56289 192P10392-PTS
C211 NOT USED
C212 0180-0374 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C213 0180-0374 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C214 0180-0137 C:FXD ELECT 100 UF 20% 10VDCW 56289 150D107X0010R2-DYS
C215 0180-0137 C:FXD ELECT 100 UF 20% 10VDCW 56289 150D107X0010R2-DYS
C216 0160-0137 C:FXD CER 0.33 UF 20% 25VDCW 56289 5C10A7 CML
C217 0160-0818 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C218 0180-0374 C:FXD TANT .10 UF 10% 20VDCW 56289 150D106X9020B2-DYS
C219 0160-0818 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C220 0160-0818 C:FXD CER 0.02 UF 20% 100VDCW 56289 C023B101H203MS27-CDH
C221 0160-0174 C:FXD CER 0.47 UF + 80-20% 25VDCW 56289 5C11B7S-CML
C222 0160-0137 C:FXD CER 0.33 UF 20% 25VDCW 56289 5C10A7 CML
C223 0180-0291 C:FXD ELECT 1.0 UF 10% 35VDCW 56289 150D105X9035A2-DYS
C224 0160-2105 C:FXD CER 0.001 UF + 100-0% 1000VDCW 72982 801-Z5V-102P
C225 0180-0094 C:FXD ELECT 100 UF + 75-10% 25VDCW 56289 30D107G025DD2-DSM
C226 0180-0094 C:FXD ELECT 100 UF + 75-10% 25VDCW 56289 30D107G025DD2-DSM
C301 0160-2074 2 C:FXD POLY 0 22 UF 1% 100VDCW 14752 410B
C302 0160-2074 C:FXD POLY 0 22 UF 1% 100VDCW 14752 410B
C402 0180-1984 1 C:FXD AL ELECT 350 UF + 75-10% 50VDCW 56289 34D357G050HJ2-DSB
C501 0150-0119 2
C502 0150-0119 2
CR101 1901-0025 6 DIODE:SILICON 100MA/1V 07263 FD 2387
CR102 1901-0025 DIODE:SILICON 100MA/1V 07263 FD 2387
CR103 1901-0025 DIODE:SILICON 100MA/1V 07263 FD 2387
CR104 1902-0034 2 DIODE:5.76V 10% 28480 1902-0034
CR105 1901-0022 2 DIODE:SILICON 0.56V AT 1 MA 28480 1901-0022
CR106 1901-0191 19 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR107 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR108 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR109 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR110 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR111 1902-0786 4 DIODE:T.C. REFERENCE JEDEC TYPE 04713 1N937
CR112 1902-0202 4 DIODE:BREAKDOWN:15.0V 5% 1W 28480 1906-0202
CR113 1902-0786 DIODE:REFERENCE JEDEC TYPE 04713 1N937
CR114 1902-0202 DIODE BREAKDOWN:15.0V 5% 1W 28480 1901-0202
CR115 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2

HP Part Number Qty Description

C:FXD CER 2X.01 µF ±20% 250WVAC
C:FXD CER 2X.01 µF ±20% 250WVAC

Code

28480 0150-0119
28480 0150-0119

Mfr Part Number

TABLE 6-1. PARTS LIST

See introduction to this section for ordering information

6-2

Reference Mfr

Designation

CR501 1901-0470 4 DIODE:SILICON 0.75A 1000PIV 28480 1901-0470
CR502 1901-0470 DIODE:SILICON 0.75A 1000PIV 28480 1901-0470
CR503 1901-0470 DIODE:SILICON 0.75A 1000PIV 28480 1901-0470
CR504 1901-0470 DIODE:SILICON 0.75A 1000PIV 28480 1901-0470
CR116 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR117 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR118 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR201 1901-0025 DIODE:SILICON 100MA/1V 07263 FD 2387
CR202 1901-0025 DIODE.SILICON 100MA/1V 07263 FD 2387
CR203 1901-0025 DIODE:SILICON 100MA/1V 07263 FD 2387
CR204 1901-0034 DIODE:5.76V 10% 28480 1902-0034
CR205 1901-0022 DIODE:SILICON 0.56V AT 1 MA 28480 1901-0022
CR206 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR207 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR208 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR209 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR210 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR211 1902-0786 DIODE:T.C. REFERENCE JEDEC TYPE 04713 1N937
CR212 1902-0202 DIODEBREAKDOWN:15.0V 5% 1W 28480 1902-0202
CR213 1902-0786 DIODE:T.C.REFERENCE JEDEC TYPE 04713 1N937
CR214 1902-0202 DIODE BREAKDOWN:15.0V 5% 1W 28480 1902-0202
CR215 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR216 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR217 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR218 1901-0191 DIODE:SILICON 0.75A 100PIV 04713 SR1358-2
CR301 1901-0159 2 DIODE:SILICON 0.75A 400PIV 04713 SR1358-4
CR302 1901-0159 DIODE:SILICON 0.75A 400PIV 04713 SR1358-4
CR401 1901-0191 DIODE:SILICON 0.75 A 100PIV 04713 SR1358-2
CR501 1901-0487 2 DIODE:SILICON 1500 PIV 28480 1901-0487
CR402 1901-0033 DIODE:SILICON 28480 1901-0033
CR502 1901-0487 DIODE:SILICON 1500 PIV 28480 1901-0487
DS301 2140-0047 4 LAMP:NEON GLOW 0.8 MILLIAMPS 08806 A1C
DS302 2140-0047 LAMP:NEON GLOW 0.8 MILLIAMPS 08806 A1C
DS303 2140-0047 LAMP:NEON GLOW 0.8 MILLIAMPS 08806 A1C
DS304 2140-0047 LAMP:NEON GLOW 0.8 MILLIAMPS 08806 A1C
DS601 1450-0495 1 LIGHT INDICATOR, WHITE PLASTIC LENS 08717 895-W-C2A-22K
F601 2110-0065 1 FUSE:0.375A 250V (FOR 230V LINE) 75915 312 375
F601 2110-0063 1 FUSE:0.75A 250V (FOR 115V LINE) 75915 312.750
F601 1400-0084 1 FUSEHOLDER:EXTRACTOR POST TYPE 75915 342014
J101 1510-0008 4 BINDING POST:RED 28480 1510-0008
J102 1510-0008 BINDING POST:RED 28480 1510-0008
J103 1910-0009 1
J201 1510-0008 BINDING POST:RED 28480 1510-0008
J202 1510-0008 BINDING POST:RED 28480 1510-0008
J203 1510-0009 1 BINDING POST:BLACK 28480 1510-0009
J601 8120-1378 1 CABLE ASSY:AC POWER CORD 70903 KH-7081
J602 1251-0292 1 CONNECTOR:FEMALE 24 PIN 28480 1251-0292
J602 1251-0293 1 CONNECTOR:24 CONTACT 28480 1251-0293
K401 07035-81640 1 RELAY 28480 07035-81640
P601 1251-2357 1 SOCKET:3-PIN MALE POWER RECEPTACLE 82389 EAC-301
Q101 1855-0067 4 TSTR:FET SI N-CHANNEL 28480 1855-0067
Q102 1855-0067 TSTR:FET SI N-CHANNEL 28480 1855-0067
Q103 1854-0201 4 TSTR:SI NPN 80131 2N3391A
Q104 1853-0020 4 TSTR:SI PNP (SELECTED FROM 2N3702) 28480 1853-0020
Q105 1854-0202 3 TSTR:SI NPN 80131 2N3390
Q106 1854-0201 TSTR:SI NPN 80131 2N3391A
Q107 1854-0202 TSTR:SI NPN 80131 2N3390
Q108 1853-0020 TSTR:SI PNP (SELECTED FROM 2N3702) 28480 1853-0020
Q109 1854-002 2 TSTR:SI NPN 07263 S17843
Q110 5060-4502 2 TRANSISTOR 28480 5060-4502
Q201 1855-0067 TSTR:FET SI N-CHANNEL 28480 1855-0067
Q202 1855-0067 TSTR:FET SI N-CHANNEL 28480 1855-0067
Q203 1854-0201 TSTR:SI NPN 80131 2N3391A
Q204 1853-0020 TSTR:SI PNP (SELECTED PROM 2N3702) 28480 1853-0020
Q205 1854-0202 TSTR:SI NPN 80131 2N3390
Q206 1854-0201 TSTR:SI NPN 80131 2N3391A
Q207 1854-0020 1 TSTR:SI NPN 28480 1854-0020
Q208 1853-0020 TSTR:SI PNP (SELECTED FROM 2N3702) 28480 1853-0020
Q209 1854-0022 TSTR:SI NPN 07263 S17843
Q210 5060-4502 TRANSISTOR 28480 5060-4502
R101 0698-5527 4 R:FXD FLM 900K OHM 0.1% 1/4W 28480 0698-5527
R102 0698-4342 6 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R103 0698-5454 2 R:FXD FLM 9K OHM 0.1% 1/8W 28480 0698-5454
R104 0698-5453 2 R:FXD FLM 900 OHM 0.1% 1/8W 28480 0698-5453
R105 0698-4343 2 R:FXD FLM 100 OHM 0.1% 1/8W 28480 0698-4343
R106 0698-5527 R:FXD FLM 900K OHM 0.1% 1/4W 28480 0698-5527
R107 0698-4342 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R108 2100-2682 4 R:VAR WW 10K OHM 10% LIN 2W 28480 2100-2682
R109 0684-1021 6 R:FXD COMP 1000 OHM 10% 1/4W 01121 CB 1021
R110 0698-3229 4 R:FXD FLM 1K OHM 1% 1/8W 28480 0698-3229

HP Part Number Qty Description

Code

Mfr Part Number

TABLE 6-1. PARTS LIST (Continued)

See introduction to this section for ordering information

6-3

Reference Mfr

Designation

R111 0698-4342 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R112 0757-0201 2 R:FXD FLM 6.81K OHM 1% 1/8W 28480 0757-0201
R113 0757-0433 2 R:FXD MET FLM 3.32K OHM 1% 1/8W 28480 0757-0433
R114 2100-0396 2 R:VAR WW 10K OHM LIN 20% 1W 28480 2100-0396
R115 0684-1531 4 R:FXD COMP 15K OHM 10% 1/4W 01121 CB 1531
R116 0684-1531 R:FXD COMP 15K OHM 10% 1/4W 01121 CB 1531
R117 0683-1045 4 R:FXD COMP 100K OHMS 5% 1/4W 01121 CB 1045
R118 0683-1045 R:FXD COMP 100K OHMS 5% 1/4W 01121 CB 1045
R119 0698-3229 R:FXD FLM 1K OHM 1% 1/8W 28480 0698-3229
R120 0698-4160 2 R:FXD FLM 866K OHM 1% 1/4W 28480 0698-4160
R121 0698-4160 R:FXD FLM 866K OHM 1% 1/4W 28480 0698-4160
R122 0684-1041 4 R:FXD COMP 100K OHM 10% 1/4W 01121 CB 1041
R123 2100-2682 R:VAR WW 10K OHM 10% LIN 2W 28480 2100-2682
R124 07035-80750 1 SLIDEWIRE ASSEMBLY 3.5K OHM 28480 07035-80750
R124 5080-7706 1 WIPER-Y-AXIS 28480 5080-7706
R125 0698-5154 1 R:FXD FLM 866 OHM 1% 1/4W 28480 0698-5154
R126 2100-2289 2 R:VAR WW 1K OHM ± 2% 2W 28480 2100-2289
R127 0683-1055 4 R:FXD COMP 1 MEGOHM 5% 1/4W 01121 CB 1055
R128 0684-4731 6 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R129 0683-2025 4 R:FXD COMP 2000 OHM 5% 1/4W 01121 CB 2025
R130 0683-2025 R:FXD COMP 2000 OHM 5% 1/4W 01121 CB 2025
R131 0684-2731 2 R:FXD COMP 27K OHM 10% 1/4W 01121 CB 2731
R132 0684-4731 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R133 0683-1055 R:FXD COMP 1 MEGOHM 5% 1/4W 01121 CB 1055
R134 0684-1541 4 R:FXD COMP 150K OHM 10% 1/4W 01121 CB 1541
R135 0684-1541 R:FXD COMP 150K OHM 10% 1/4W 01121 CB 1541
R136 0699-0001 2 R:FXD COMP 2.7 OHM 10% 1/2W 01121 EB 27G1
R137 2100-1729 2 R:VAR WW 10 OHM 20% LIN 2W 28480 2100-1729
R138 0684-4741 4 R:FXD COMP 470K OHM 10% 1/4W 01121 CB 4741
R139 0684-1031 2 R:FXD COMP 10K OHM 10% 1/4W 01121 CB 1031
R140 0684-4741 R:FXD COMP 470K OHM 10% 1/4W 01121 CB 4741
R141 0684-1831 2 R:FXD COMP 18K OHM 10% 1/4W 01121 CB 1831
R142 0684-3311 4 R:FXD COMP 33K OHM 10% 1/4W 01121 CB 3331
R143 0683-3945 2 R:FXD COMP 390K OHM 5% 1/4W 01121 CB 3945
R144 0684-4731 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R145 0683-2225 2 R:FXD COMP 2.2K OHM 5% 1/4W 01121 CB 2225
R147 0684-1841 2 R:FXD COMP 180K OHM 10% 1/4W 01121 CB 1841
R148 0684-1041 R:FXD COMP 100K OHM 10% 1/4W 01121 CB 1041
R149 0684-1021 R:FXD COMP 1000 OHM 10% 1/4W 01121 CB 1021
R150 0684-3331 R:FXD COMP 33K OHM 10% 1/4W 01121 CB 3331
R151 0684-1021 R:FXD COMP 1000 OHM 10% 1/4W 01121 CB 1021
R152 0684-4711 2 R:FXD COMP 470 OHM 10% 1/4W 01121 CB 4711
R153 0684-1521 2 R:FXD COMP 1500 OHM 10% 1/4W 01121 CB 1521
R154 0683-4725 R:FXD COMP 4700 OHM5% 1/4W 01121 CB 4725
R155 0813-0046 2 R:FXD WW 1 OHM 10% 3W 28480 0813-0046
R156 0683-6215 4 R:FXP COMP 620 OHM 5% 1/4W 01121 CB 6215
R157 0761-0049 4 R:FXD MET OX 200 OHM 5% 1W 28480 0761-0049
R158 0683-6215 R:FXD COMP 620 OHM 5% 1/4W 01121 CB 6215
R159 0761-0049 R:FXD MET OX 200 OHM 5% 1W 28480 0761-0049
R201 0698-5527 R:FXD FLM 900K OHM 0.1% 1/4W 28480 0698-5527
R202 0698-4342 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R203 0698-5454 R:FXD FLM 9K OHM 0.1% 1/8W 28480 0698-5454
R204 0698-5453 R:FXD FLM 900 OHM 0.1% 1/8W 28480 0698-5453
R205 0698-4343 R:FXD FLM 100 OHM 0.1% 1/8W 28480 0698-4343
R206 0691-5527 R:FXD FLM 900K OHM 0.1% 1/8W 28480 0698-5527
R207 0698-4342 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R208 2100-2682 R:VAR WW 10K OHM 10% LIN 2W 28480 2100-2682
R209 0684-1021 R:FXD COMP 1000 OHM 10% 1/4W 01121 CB 1021
R210 0698-3229 R:FXD FLM 1K OHM 1% 1/8W 28480 0698-3229
R211 0698-4342 R:FXD FLM 90K OHM 0.1% 1/8W 28480 0698-4342
R212 0757-0201 R:FXD FLM 6.81K OHM 1% 1/8W 28480 0757-0201
R213 0757-0433 R:FXD MET 3.32K OHM 1% 1/8W 28480 0757-0433
R214 0683-4725 1 R:FXD COMP 4700 OHM 5% 1/4W 28480 2100-0396
R215 0684-1531 R:FXD COMP 15K OHM 10% 1/4W 01121 CB 1531
R216 0684-1531 R:FXD COMP 15K OHM 10% 1/4W 01121 CB 1531
R217 0683-1045 R:FXD COMP 100K OHM 5% 1/4W 01121 CB 1045
R218 0683-1045 R:FXD COMP 100K OHM 5% 1/4W 01121 CB 1045
R219 0698-3229 R:FXD FLM 1K OHM 1% 1/8W 28480 0698-3229
R220 0698-4159 2 R:FXD FLM 604K OHM 1% 1/4W 28480 0698-4159
R221 0698-4159 R:FXD FLM 604K OHM 1% 1/4W 28480 0698-4159

HP Part Number Qty Description

Code

Mfr Part Number

TABLE 6-1. PARTS LIST (Continued)

See introduction to this section for ordering information

6-4

Reference Mfr

Designation

R222 0684-1041 R:FXD COMP 100K OHM 10% 1/4W 01121 CB 1041
R223 2100-2682 R:VAR WW 10K OHM 10% LIN 2W 28480 2100-2682
R224 07035-80730 1 SLIDEWIRE ASSY:5K OHM 28480 07035-80730
R224 5060-4570 1 WIPER X-AXIS 28480 5060-4570
R225 0757-0427 1 R:FXD MET FLM 1.5K OHM 1% 1/8W 28480 0757-0427
R226 2100-2289 R:VAR 1K ± 20% 2W 28480 2100-2289
R227 0683-1055 R:FXD COMP 1 MEGOHM 5% 1/4W 01121 CB 1055
R228 0683-4731 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R229 0683-2025 R:FXD COMP 2000 OHM 5% 1/4W 01121 CB 2025
R230 0683-2025 R:FXD COMP 2000 OHM 5% 1/4W 01121 CB 2025
R231 0684-2731 R:FXD COMP 27K OHM 10% 1/4W 01121 CB 2731
R232 0684-4731 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R233 0683-1055 R:FXD COMP 1 MEGOHM 5% 1/4W 01121 CB 1055
R234 0684-1541 R:FXD COMP 150K OHM 10% 1/4W 01121 CB 1541
R235 0684-1541 R:FXD COMP 150K OHM 10% 1/4W 01121 CB 1541
R236 0699-0001 R:FXD COMP 2.7 OHM 10% 1/2W 01121 EB 27G1
R237 2100-1729 R:VAR WW 10 OHM 20% LIN 2W 28480 2100-1729
R238 0684-4741 R:FXD COMP 470K OHM 10% 1/4W 01121 CB 4741
R239 0684-1031 R:FXD COMP 10K OHM 10% 1/4W 01121 CB 1031
R240 0684-4741 R:FXD COMP 470K OHM 10% 1/4W 01121 CB 4741
R241 0684-1831 R:FXD COMP 18K OHM10% 1/8W 01121 CB 1831
R242 0684-3331 R:FXD COMP 33K OHM 10% 1/4W 01121 CB 3331
R243 0683-3945 R:FXD COMP 390K OHM 5% 1/4W 01121 CB 3945
R244 0684-4731 R:FXD COMP 47K OHM 10% 1/4W 01121 CB 4731
R245 0683-2225 R:FXD COMP 2.2K OHM 5% 1/4W 01121 CB 2225
R246 0684-6811 R:FXD COMP 680 OHM 10% 1/4W 01121 CB 6811
R247 0684-1841 R:FXD COMP 180K OHM 10% 1/4W 01121 CB 1841
R248 0684-1041 R:FXD COMP 100K OHM 10% 1/4W 01121 CB 1041
R249 0684-1021 R:FXD COMP 1000 OHM 10% 1/4W 01121 CB 1021
R250 0684-3331 R:FXD COMP 33K OHM 10% 1/4W 01121 CB 3331
R251 0684-1021 R:FXD COMP 1000 OHM10%1/4W 01121 CB 1021
R252 0684-4711 R:FXD COMP 470 OHM 10% 1/4W 01121 CB 4711
R253 0684-1521 R:FXD COMP 1500 OHM 10% 1/4W 01121 CB 1521
R254 0683-4725 R:FXD COMP 4700 OHM 5% 1/4W 01121 CB 4725
R255 0813-0046 R:FXD WW 1 OHM 10% 3W 28480 0813-0046
R256 0683-6215 R:FXD COMP 620 OHM 5% 1/4W 01121 CB 6215
R257 0761-0049 R:FXD MET OX 200 OHM 5% 1W 28480 0761-0049
R258 0683-6215 R:FXD COMP 620 OHM 5% 1/4W 01121 CB 6215
R259 0761-0049 R:FXD MET OX 200 OHM 5% 1W 28480 0761-0049
R301 0684-6831 4 R:FXD COMP 68K OHM 10% 1/4W 01121 CB 6831
R302 0684-6831 R:FXD COMP 68K OHM 10% 1/4W 01121 CB 6831
R303 0684-6831 R:FXD COMP 68K OHM 10% 1/4W 01121 CB 6831
R304 0684-6831 R:FXD COMP 68K OHM10% 1/4W 01121 CB 6831
R401 0811-1202 1 R:FXD WW 50 OHM 5% 3W 28480 0811-1202
R501 0683-6845 I
R502 0698-8754 2
R503 0698-8754 2
R601 NOT USED
R602 2100-1621 1 R:VAR 5K WW 4W 28480 2100-1621
S101 3130-0166 2 SECTION:ROTARY SWITCH 28480 3130-0166
S201 3130-0166 SECTION:ROTARY SWITCH 28480 3130-0166
S401 3101-1702 2 SWITCH:TOGGLE SPDT 18911 8926K124
S501 3101-1702 SWITCH:TOGGLE SPDT 18911 8926K124
S601 3101-2404 1 SWITCH:TOGGLE SPDT 82389 11A-1242
S602 3101-1174 1 SWITCH:TOGGLE SPDT 18911 7511K4
T601 5060-6857 TRANSFORMER ASSEMBLY
V101 1990-0072 4 PHOTOCONDUCTOR:2-LEAD, T0-5 PACKAGE 28480 1990-0072
V102 1990-0072 PHOTOCONDUCTOR:2-LEAD, T0-5 PACKAGE 28480 1990-0072
V201 1990-0072 PHOTOCONDUCTOR:2-LEAD, T0-5 PACKAGE 28480 1990-0072
V202 1990-0072 PHOTOCONDUCTOR:2-LEAD, T0-5 PACKAGE 28480 1990-0072
R504 0698-3453 2 R:FXD 196K ±1% 1/8W 28480 0698-3453
R505 0698-3453 2 R:FXD 196K ±1% 1/8W 28480 0698-3453

HP Part Number Qty Description

R:FXD 680K ±5% 1/4W
R:FXD 10 MEG ±1% 1/4W
R:FXD 10 MEG ±1% 1/4W

Code

28480 0683-6845
28480 0698-8754
28480 0698-8754

Mfr Part Number

TABLE 6-1. PARTS LIST (Continued)

See introduction to this section for ordering information

6-5

TABLE 6-2. MISCELLANEOUS PARTS

Circuit Mfr Part

Symbol

Part No. Description Typical Mfr

No.

MECHANICAL, ELECTRICAL, ETC.

1251-0293 Connector, 24-pin (mate for J-602) Amphenol 57-30240
1400-0084 Fuse holder Littlefuse 342004
17999-06494 Pulley, Drive cable (white plastic) H-P 17999-06494
17999-06460 Spring, Cable tension H-P 17999-06460
17999-16046 Clamp and Pad Assy (for shipping) H-P 17999-16046
4040-0011 Dust Cover (plastic) Allen Plastic
5080-3627 X Axis Stringing Kit H-P 5080-3627
1251-0148 Receptacle, Power, Cord Tower Mfg. H-1061 I.G.
1500-0043 Belt, Drive, clutch (mylar) Kinelogic Corp.
5080-3635 Lubricant Slidewire H-P 5080-3635
8120-1378 Power cord, 7.5 ft. Belden KMS-7041
5060-0761 Foot, Stacking H-P 50600761
0703501660 Bracket
8120-039 Spectrastrip (9 conductor)(Y-axis trailing Spectrastrip

cable)
1490-0080 Shorting Links (Guard Straps) H-P 1490-0080
07035-01020 Panel Control (English) H-P 07035-01020
07035-62260 Hood Assembly (Standard)
07035-01030 Panel Control (Metric) H-P 07035-01030
07035-01000 Panel, Side, RH and LH H-P 07035-01000
07004-01860 Panel, front, rear H-P 07004-01860
07035-61440 Cable Assembly
07035-00511 Cover, Bottom H-P 07035-00511
07035-61660 Rear Hood Assy (Standard) H-P 07035-61660
07035-61670 Rear Hood Assy (Metric) H-P 07035-61670
07035-64270 Hood Assembly (Metric) Option 001
07004-60640 Solenoid, Pen lit (Serial Prefix 826 and below H-P

require index pointer 07005-00730)
07035-62160 Clutch Assy, X-axis H-P 07035-62160
07035-81000 Table, Electrostatic H-P 07035-81000
07035-80730 Slidewire, X-axis H-P 07035-80730
07035-81020 Shipping Carton H-P 07035-81020
09125-20350 Plunger Assembly, solenoid H-P

ACCESSORY KIT, PAPER, INK

07035-82660 Accessory Kit H-P 0703-82660
508-1190 Pen, Disposable, Red H-P 5081-1990
5081-1191 Pen, Disposable, Blue H-P 5081-1191
5081-1192 Pen, Disposable, Green H-P 5081-1192
5081-1193 Pen, Disposable, Black H-P 5081-1193
9270-1006 Chart Paper, Standard (heavy) Gubelman H-10070/A
9270-1007 Chart Paper, Standard (light) Gubelman L-10070/A
9270-1023 Chart Paper, Metric (heavy) Gubelman
9270-1027 Chart Paper, Metric (light) Gubelman

0370-0025 Zero & Vernier Control H-P 03700025
0370-0112 Attenuator H-P 03700112

6-6

KNOBS

TABLE 6-3. RECOMMENDED ONE YEAR ISOLATED SPARE PARTS LIST

Circuit

Symbol Part No. Description Typical Mfr Mfr Part No. RS

B-101 5080-3696 Servo Motor, Y-axis H-P 5080-3696 1
B-201 5080-3695 Servo Motor, X-axis H-P 5080-3695 1
C-402 0180-1984

Cap, Elect, 350µf, +75 -10% 50wvdc

Sprague 34D357G050 1
CR-104 1902-0034 Diode, Zener, 5.76v, ±10% TRW PS18237 1
CR-204
CR-111
CR-113 1902-0786 Diode, Zener, 9.0v, ±5% Motorola IN937 1
CR-211
CR-213
CR-112
CR-114 1902-0202 Diode, Zener, 15v, 5%, 1w Motorola SZ11213-191 1
CR-212
CR-214
CR-501 1901-0487 Diode, Silicon Semtech SS1138 2
CR-502
DS-301
DS-302 2140-0047 Lamp, Neon, 1/10w, 0.8ma, G. E. A1C 2
DS-303
DS-304 68K ohms
DS-304
DS-601 1450-0495 Indicator Light Sloan Co. 859-W-(ZA-22K)
F-601 2110-0063 Fuse, 750 mA Littlefuse 312.750 5

2110-0065 Fuse, 375 mA Littlefuse 312.375

K-401 07004 Solenoid, Pen Lift H-P 07004-60650 1

60650
09125 Plunger Assembly, Solenoid H-P 09125-20350 1

20350
Q-101
Q-102 1855-0067 Transistor, Field Effect Siliconix Inc. E-101 2
Q-201
Q-202
Q-103
Q-406 1854-0201 Transistor, NPN Silicon G. E. 2N3391A 2
Q-203
Q-206
Q-104
Q-108 1853-0020 Transistor, PNP Silicon Texas Inst. SM-9143 2
Q-204
Q-208
Q-105
Q-107 1854-0202 Transistor, NPN Silicon G. E. 2N3390 2
Q-205
Q-207
Q-109 1854-0022 Transistor, NPN Silicon Fairchild 1
Q-209
Q-110 5060-4502 Transistor Assembly, NPN Silicon H-P 5060-4502 1
Q-210

6-7

TABLE 6-3. RECOMMENDED ONE YEAR ISOLATED SPARE PARTS LIST (Continued)

Circuit

Symbol Part No. Description Typical Mfr Mfr Part No. RS

R-124 07035- Resistor, Variable, 3.5K (Slidewire) H-P 07035-80750 1

80750

5080-7706 Wiper Assembly, (Y-axis) H-P 2
R-224 07035- Resistor, Variable, 5K (Slidewire) H-P 07035-80730 1

80730

5060-4570 Wiper Assembly, (X-axis) For serial H-P 2

prefixes below 823, coil and wiper

bracket 5060-4569, also required.
R-155
R-255 0813-0046

Resistor, ww, 1 ohm, ±10%, 3w

Sprague 242E 1
V-101
V102 1990-0072 Photoconductor H-P 1990-0072 2
V-201
V-202

1500-0043 Belt, Drive, Clutch (Mylar) Kinelogic 1

Corp.

5080-3627 Restringing Kit (X-axis) H-P 5080-3627 1
07035- Cable Assembly (Y-axis) H-P 07035-61420 1

61420
07035- Trailing Cable (Y-axis) H-P 8120-1039 1

60460
07035- Clutch Assembly, X-axis H-P 07035-62160 1

62160
5060-6428 Pen Holder H-P 5060-6428 1

TABLE 6-4. MANUFACTURER'S CODE LIST

MFR NO. MANUFACTURER'S NAME ADDRESS ZIP CODE

01121 Alien Bradley Company Milwaukee, Wis. 53204
04713 Motorola Semiconductor Products Inc. Phoenix, Ariz. 85008
07263 Fairchild Camera & Inst. Corp. Semiconductor Div. Mountain View, Calif. 94040
08806 G. E. Co. Miniature Lamp Dept. Cleveland, Ohio 44112
14655 Cornell Dubilier Elect, Div. Federal Pacific Elect. Co. Newark, N. J. 07105
14752 Electro-Cube, Inc. San Gabriel, Calif. 91776
18911 Cutler-Hammer Inc. Durant Digital Inst. Milwaukee, Wis. 53201
28480 Hewlett-Packard Company Palo Alto, Calif. 94304
56289 Sprague Electric Co. N. Adams, Mass. 01247
70903 Belden Corp. Chicago, Ill. 60644
72619 Dialight Corp. Brooklyn, N. Y. 11237
72982 Erie Technological Prod. Inc. Erie, Pa. 16512
75915 Littlefuse Inc. Des Plaines, Ill. 60016
80131 Electronic Industries Association Washington, D. C. 20006
82389 Switchraft, Inc. Chicago, Ill. 60630
91418 Radio Materials Co. Chicago, Ill. 60646

6-8

TM 11-6625-2850-14&P

FIGURE 6-1. EXPLODED VIEW-CABINET

6-9

TM 11-6625-2850-14&P

FIGURE 6-2. EXPLODED VIEW-CARRIAGE ARM (SHEET 1 OF 2)

6-10

B/N Part No. Description Typical Mfr.

1 0360-0243 Solder Lug, Flat #2 Zierick Mfg. Co.
2 1460-0940 Spring, Retaining Superior Spring
3 0520-0066 Screw, Machine, 2-56 x 3/16 PH, PD, SS Schnitzer Alloy
4 0520-0163 Screw, Machine, 2-56 x 3/16 FH, PD, SS Hewlett-Packard
5 2200-0710 Screw, Machine, 4/40 x 3/8 Truss, Set, Pass, Slot
6 0570-0142 Screw, Set 2-56 x 1/8 Spline Dr. Bristol
7 0570-0190 Screw, Machine 0-80 x 1/8 FH, PD, SS
8 0590-0149 Nut, Hex 0-80 SS Corland Co.

9 1400-0304 Clip - Component Augat, Inc.
10 1410-0941 Ball Bearing New Hampshire
11 1410-0269 Ball Bearing New Hampshire
12 1460-1201 Spring, Pen Lift Superior Spring
13 5000-4225 Yoke, Cable Hewlett-Packard
14 5080-3633 Motor Replacement Kit Hewlett-Packard
15 2190-0087 Washer, Lock, Helical #8 Eaton Mfg. Co.
16 2190-0108 Washer, Lock, Helical #4
17 2190-0094 Washer, Lock, Helical #2
18 3050-0303 Washer, Flat #2 Corland Co.
19 2200-0048 Screw, Machine 4-40 x 3/8 FH, PD, SS
20 2200-0056 Screw, Machine 4-40 x 3/16 FH, PD, SS
21 2200-0143 Screw, Machine 4-40 x 3/8 FH, PD, SS Schnitzer Alloy
22 0570-1103 Screw, Shouldered 4-40 x 3/8 Hewlett-Packard
23 2270-0022 Screw, Machine 4-40 x 3/16 FH, PD, SS
24 Not used
25 2270-0049 Screw, Machine 4-40 x 7/16 FH, PD, SS
26 3030-0169 Screw, Set 4-40 x 1/8 Spline Dr. Bristol
27 3030-0222 Washer, Flat #4 Western Washer
28 3050-0394 Washer, Flat #4 shim SS Hewlett-Packard
29 07035-61850 Block, Servo Motor Hewlett-Packard
30 5080-3696 Servo Motor Y-Axis Hewlett-Packard
31 07035-00230 Rear Mount, Scale Hewlett-Packard
32 5060-4569 Bracket-Coil & Wiper Hewlett-Packard
33 07035-02370 Clamp, Cable Hewlett-Packard
34 0340-0418 Bushing, Insulation Nylomatic N5228
35 Not Used
36 07035-20200 Pulley, Return (Lower) Hewlett-Packard
37 07035-62420 Cleat, Motor Assembly Hewlett-Packard
38 07035-20240 Stud, Pulley Return Hewlett-Packard
39 07035-20280 Wheel, Pen Arm Hewlett-Packard
40 07035-20330 Mounting Block, Pen Arm Hewlett-Packard
41 07035-20350 Screw, Shoulder Hewlett-Packard
42 07005-00730 Pointer, Index (X - Axis) Hewlett-Packard
43 07035-22020 Flywheel Hewlett-Packard
44 07035-20310 Pulley, Pen Drive (Upper) Hewlett-Packard
45 07035-22190 Stop, Pen Block Hewlett-Packard
46 07035-40370 Carriage Block, Pen Hewlett-Packard
47 07034-40020 Block, Pen Arm Hewlett-Packard
48 07034-60430 Pen Scale Assembly - English Scale Hewlett-Packard

49 0510-0724 Ring, Grip Hewlett-Packard
50 07035-60590 Gear, Pen Drive Assembly Hewlett-Packard
51 07035-60700 Bearing Adjustment Assembly Hewlett-Packard
52 5060-4570 Wiper Assembly (Prefix 823 & above) Hewlett-Packard

53 07035-60860 Wheel Assembly, Pen Carriage Hewlett-Packard
54 5060-6428 Pen Holder Assembly Hewlett-Packard
55 07035-80750 Pen Arm Assembly Hewlett-Packard
56 5060-6538 Pen Lift Assembly Hewlett-Packard
57 07035-61420 Pen Carriage Cable Assembly Hewlett-Packard
58 07004-60640 Solenoid Assembly (Below serial prefix 826 requires Hewlett-Packard

59 07035-61700 Pen Drive Assembly Hewlett-Packard
60 09125-20350 Plunger, Solenoid Assembly Hewlett-Packard
61 5061-1190 Pen, Disposable, Red HP

62 5080-7706 Wiper Assembly (Y - Axis) Hewlett-Packard
63 3050-0710 Washer, .130 ID, .250 OD, .010 THK Western Washer
64 03060-1626 Terminal, Stud Hewlett-Packard

65 0610-0810 Retaining Ring HP

07034-60450 Pen Scale Assembly - Metric Scale Hewlett-Packard

07035-60520 Wiper Conversion Kit (Prefix below 823)

index pointer 07005-00730)

5061-1191 Pen, Disposable, Blue HP
5061-1192 Pen, Disposable, Green HP
5061-1193 Pen, Disposable, Black HP

FIGURE 6-2. EXPLODED VIEW-CARRIAGE ARM (SHEET 2 OF 2)

6-11/(6-12 blank)

SECTION VII

TROUBLESHOOTING

7-1. INTRODUCTION

7-2. CONTENT
7-3. This section contains instructions for troubleshooting the

Model 7035B. Component location photographs, schematics,
and a troubleshooting index are supplied to aid in
troubleshooting.

7-4. TROUBLESHOOTING

7-5. REQUIREMENTS
7-6. Troubleshooting should be performed in a logical manner.

The concept of bracketing should be established, such as

determining which circuits or sections are not operating or are
operating abnormally. This is generally the fastest method to
locate trouble in a closed loop circuit. When troubleshooting
utilize the photographs and schematics presented in this
section, Figures 7-1 through 7-3.

7-7. TROUBLESHOOTING INDEX
7-8. The troubleshooting index, Table 7-1, lists other possible

malfunctions, suspected causes, and remedies. Use
component location photographs and schematics for backup
when searching out a problem area.

7-1

TABLE 7-1. 7035B TROUBLESHOOTING INDEX

PROBLEM POSSIBLE CAUSE CURE

1. One position of pen produces "Dirty" slidewire. High contact Clean slidewire (see paragraph 5-11).
excessive jitter that repeats resistance between slidewire
each time the pen reaches wiper and either resistance ele­this position. ment or pickoff strip.

2. Excessive pen jitter (small a. Amplifier gain adjusted too high. a. Adjust (lower) gain per
amplitude). paragraph 5-92.

b. Strap between front panel guard b. Connect strap.

terminal and negative input

terminal disconnected.
c. Excessive common mode signal. c. See Table 1-1.
d. Excessive differential input d. See Table 1-1.

signal noise.
e. "Dirty" slidewire. e. Clean slidewire (see paragraph 5-11).

3. Excessive Y-axis retrace a. Amplifier gain too low. a. Adjust gain (paragraph 5-92).
hysteresis (any slope).

b. Source impedance too high (1 mv/ b. Lower source impedance

inch, 0.4 mv/cm) range only. and/or increase amplifier

gain (paragraph 5-92).

c. Drive string too loose. Measure c. Tighten drive string (paragraph 5-67).

tension per paragraph 5-66.

d. Pen carriage wheels set too tight. d. Adjust pen carriage (per

paragraph 5-71).

e. Insufficient backlash in gears (too e. Adjust backlash (paragraph 5-69).

tight).
f. Motor brushes excessively worn. f. Replace brushes (paragraph 5-38).
g. Pen speed too fast. Retrace g. Decrease retrace pen speed.

error should be small only at pen

speeds below 1 inch/sec.
h. Bearing in drive train faulty. h. Replace bearing.
i. Faulty neon bulb in photochopper. i. Replace bulk (aging not required).
j. Excessive differential noise on j. See Table 1-1.

input signal.
k. Excessive friction. k. Clean and lubricate per

paragraphs 5-9 and 5-13.

4. Excessive X-axis retrace a. Amplifier gain too low. a. Adjust gain (paragraph 5-92).
hysteresis (any slope).

b. Source impedance too high (1 mv/ b. Lower source impedance and/

inch, 0.4 mv/cm) range only. or increase amplifier gain

(paragraph 5-92).

7-2

c. Drive belt too loose. Measure c. Tighten belt (paragraph 5-79).

per paragraph 5-78.

TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)

PROBLEM POSSIBLE CAUSE CURE

4. (cont) d. X-axis slider rod bearings too d. Adjust slide rod bearings

tight. (paragraph 5-85).

e. Insufficient backlash in gears e. Adjust backlash (paragraph 5-83).

(too tight).
f. Motor brushes excessively worn. f. Replace brushes (paragraph 5-38).
g. Pen speed too fast. Retrace g. Decrease retrace pen

error should be small only at pen speed.

speeds below 1 inch/sec.
h. Bearing in drive train faulty. h. Replace bearing (paragraph 5-87).
i. Faulty neon bulb in photochopper. i. Replace faulty bulb (aging not required).
j. Excessive differential noise on j. See Table 1-1.

input signal.
k. Grease on drive belt. k. Clean

5. Excessive hysteresis in a. Source impedance too high or low a. Adjust R-114 (paragraph 5-97).
45 retrace (X and Y steep (1 my/inch range only) causing This control will adjust the phasing
angle retrace O. K.). excessive phase shift in input nominal source impedance. Extremes

filter. can be compensated for only by

reducing the pen speed, thereby
reducing the phase shift.

b. Operating on ranges other than b. Possible cures:

calibrated positions. 1. Adjust R-114.

2. Reduce pen speed.

c. Phase relationship problem in c. Examine signal source.

signal source.

d. Phase adjustment (R-114) mis - d. Adjust R-114 per paragraph 5-97.

adjusted.

e. Pen carriage wheels too loose. e. Adjust pen carriage wheels

(paragraph 5-71).

6. Calibration incorrect. a. Calibration controls (front panel a. Calibrate unit per paragraph 5-95.

screw driver adj) incorrectly
adjusted.

b. Recording paper inaccurate due to b. Calibrate unit per paragraph 5-95.

poor printing or environmental
effects.

7. High voltage ranges won't Leakage on surface of printed Wash board per paragraph 5-9.
hold calibration. circuit board.

8. X-axis arm seems to a. Upper support screws (two) not a. Align arm and tighten (see
wobble - not rigidly held. tight (see figure 5-6). paragraph 5-73).
(Slight vertical wobble at
zero end of arm is b. X-axis slider rod bearings too b. Adjust slider rod bearing
normal.) loose. (paragraph 5-85).

7-3

TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)

PROBLEM POSSIBLE CAUSE CURE

8. (cont) c. Excessive X-axis gear backlash. c. Adjust backlash (paragraph 5-83).

9. X-axis motor stalls when X drive belt too tight. Measure Adjust (loosen) drive belt
end of scale stops are per paragraph 5-78. (paragraph 5-79).
hit. (Prolonged operation
in this condition may
damage motor or ampli­fier - motor must not
stall. )

10. Recorder response ex- Input signal source impedance too Use lower source impedance.
tremely slow - operating high (paragraph 5-92).
on 1 mv/inch (0.4 mv/cm)
range.

11. Zero position not repeat- No source impedance connected to Place resistance across
able during recorder input. input terminals (+ to -).
"set-up" - using 1 mv/ R to be 20K or less.
inch range (0.4 mv/cm).

12. Pen carriage wobbles Pen carriage wheels too hose. Adjust pen carriage wheels
causing poor writing. per paragraph 5-71.

13. Y-axis moves in jerks, a. Drive string too loose. Measure a. Tighten drive string (see
seems to occasionally per paragraph 5-66. paragraph 5-67).
bind or stick.

b. Pen carriage wheels set too tight. b. Adjust pen carriage per

paragraph 5-71.

c. Insufficient backlash in gears (too c. Adjust backlash (paragraph 5-69).

tight).
d. Motor brushes excessively worn. d. Replace brushes (see paragraph 5-38).
e. Motor brush stuck, held off e. Free-up brush (see paragraph 5-40).

commutator.
f. Bearing in drive system faulty. f. Replace bearing.
g. Excessive mechanical friction. g. Clean and lubricate per

Unit needs general cleaning and paragraphs 5-9, 5-12.

lubrication.

14. X-axis moves in jerks, a. X-axis slider rod bearings too a. Adjust slider rod bearings
seems to occasionally tight. (paragraph 5-85).
bind or stick.

b. X-gear backlash insufficient (too b. Adjust backlash (paragraph 5-83).

tight).
c. Motor brushes excessively worn. c. Replace brushes (paragraph 5-38).
d. Motor brush stuck and therefore d. See paragraph 5-40.

held off commutator.
e. Bearing in drive train faulty. e. Replace bearing (paragraph 5-87).
f. Excessive friction. f. Clean and lubricate per

paragraphs 5-9 and 5-12.

7-4

TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)

PROBLEM POSSIBLE CAUSE CURE

15. Y-axis acceleration too a. Drive string too loose. Measure a. Tighten drive string
slow. tension per paragraph 5-66. (see paragraph 5-67).

b. Input signal source impedance too high b. Lower source impedance and/or

(1 mv/inch, 0.4 mv/cm) range only. increase amplifier gain (see

paragraph 5-92).
c. Bearing in drive train faulty. c. Replace bearing.
d. Faulty neon bulb in photochopper. d. Replace bulb (aging not required).
e. Excessive differential noise on e. See Table 1-1.

input signal.

f. Excessive friction. f. Clean and lubricate per

paragraphs 5-9 and 5-12.

16. X-axis acceleration too a. Drive belt too loose. Measure a. Tighten drive belt
slow. tension per paragraph 5-78. (paragraph 5-79).

b. Input signal source impedance too b. Lower source impedance

high (1 mv/inch, 0.4 mv/cm) and/or increase amplifier
range only. gain (see paragraph 5-92).

c. Bearing in drive train faulty. c. Replace bearing (see

paragraph 5-87).

d. Faulty neon bulb in photochopper. d. Replace bulb (aging not

required).

e. Excessive differential noise on e. See Table 1-1.

input signal.

f. Excessive friction. f. Clean and lubricate per

paragraphs 5-9 and 5-12.

17. Maximum pen speed too a. Power line voltage too low. (Pen a. Increase line voltage (i.e.,
slow. speed is dependent on line voltage.) with Variac).

b. Operating on 115-vol line with b. Correct switch position.

voltage selector switch in 230­volt position (front panel neon
won't light).

c. Bearing in drive train faulty. c. Replace bearing. (See

paragraph 5-87).

d. Faulty neon in photochopper. d. Replace faulty neon (no

aging required).

e. Excessive differential noise e. See Table 1-1.

on input signal.

f. Excessive friction. f. Clean and lubricate per

paragraphs 5-9 and 5-12.

18. Excessive Y-axis over- a. Drive string too loose. Measure a. Tighten drive string
shoot. tension per paragraph 5-66. (paragraph 5-67).

7-5

TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)

PROBLEM POSSIBLE CAUSE CURE

18. (cont) b. Amplifier gain too low. b. Adjust amplifier gain

(see paragraph 5-92).

c. Damping capacitor improper c. Replace capacitor. Increasing

value. value decreases overshoot.

19. Excessive X-axis over- a. Drive belt too loose. Measure a. Tighten drive belt
shoot. per paragraph 5-78. (paragraph 5-79).

b. Amplifier gain too low. b. Adjust amplifier gain

(see paragraph 5-92).

c. Damping capacitor improper c. Replace with proper value

value. capacitor. Increasing

value decreases overshoot.

20. X-axis produces loud, audible X-axis backlash too loose or too Adjust backlash (paragraph 5-83).
noise when moved fast. tight.

21. Y-axis won't go full a. Drive string too tight, causing a. Loosen drive string
scale (stops short by spring to be over-extended, (paragraph 5-67).
approximately 1/16 hitting stop.
inch to 1/4 inch).

b. Zero pot wiper resistor b. Replace resistor.

improper value (R-120).

22. One axis runs erratically a. Motor brush not properly seated a. Inspect brush. Replace
at high speed in one or both to commutator. per paragraph 5-38 or
directions. "run-in" motor to seat brush.

b. Motor brush tends to "cock" in b. Replace motor per

one direction of rotation and paragraphs 5-34 and 5-35.
binds in brush holder.

23. Slewing one axis causes a. CR-111 open a. Replace.
disturbance on other axiis.

b. Lucite tubes in photochopper b. Cover with fish-paper (see

uncovered. Figure 5-24).

24. Paper holddown weak. a. Table surface contaminated (see a. Wash with soap and water

paragraph 5-9). (paragraph 5-9).

b. Paper surface too rough, insufficient b. Contact factory.

contact area (i.e., parchment or
curled film).

c. One of the two table power leads c. Connect lead (Figure 5-24).

disconnected.

25. Paper holddown inoperative. Table power leads disconnected. Connect leads (Figure 5-24).

26. Servo gain varies Excessive contact resistance in Replace
erratically. gain potentiometer R-137 or R-237.

27. Very erratic operation. a. Operation on 115-volt line with voltage a. Correct switch position.

7-6

selector switch in 230 position (front
panel neon will not light).

TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)

PROBLEM POSSIBLE CAUSE CURE

27. (cont) b. Bearing in drive train faulty. b. Replace bearing

(paragraph 5-87).

c. Motor brushes excessively c. Replace brushes (see

worn. paragraph 5-38).

d. Motor brush stuck, held off d. See paragraph 5-39.

commutator.

e. Excessive friction. e. Clean and lubricate per

paragraphs 5-9 and 5-12.

28. Common mode rejection a. Guard strap disconnected. a. Connect strap.
poor.

b. Guard not connected directly b. Remove guard strap and

to common mode source. connect guard input to

source.

c. Source impedance unbalance too c. See Table 1-1.

high.

29. One axis motor will hot a. Motor brushes excessively worn, a. Replace brushes (see
respond to input signal. paragraph 5-38).
(Gears and motor
mechanically free and b. Motor brush stuck, held off b. Free-up brush (see
electronics providing commutator. paragraph 5-39).
proper drive signal to
motor).

30. Recorder dives hard to a. Faulty slidewire wiper. a. Replace wiper (see
end of scale, will not paragraphs 5-26 and 5-30).
balance.

b. Open In balance circuit. b. Check balance circuits in

fig. 7-3 to locate faulty
components.

c. Phase reversal in servo system c. Correct by reversing wires

(common occurrence during on servo motor.
repair work).

31. Recorder completely a. Fuse blown. a. Locate and correct cause of
dead (Autogrip blown fuse. Replace fuse.
inoperative, power neon
indicator inoperative).

b. 115 volt/230 volt switch in 230 b. Correct switch position.

volt position when powered on
115 volts.

32. Recorder dead (Auto- Neon bulbs in photochopper not lit. Check voltages in neon
grip operates, power Fault in neon power supply. power supply.
neon indicator operates).

7-7

FIGURE 7-1. COMPONENT IDENTIFICATION-FRAME

7-8

TM 11-6625-2850-14&P

Figure 7-2. Component Identification - Circuit Board.

7-9

TM 11-6625-2850-14&P

Figure 7-3. Schematic Model 7035B (D-07035-92550).

7-10

SECTION VIII

BACKDATING

8-1. REQUIREMENTS

8-2. DEFINITIONS
8-3. This section provides information on serial prefixes

below 845. Table 8-1 is a tabular presentation of the serial
prefix numbers and the corresponding change numbers. To
adapt this manual to the instrument on hand, determine the
serial prefix of the instrument, then refer to Table 8-1 and make
the appropriate changes to the manual.

TABLE 8-1. SERIAL PREFIX/CHANGE

NUMBER REFERENCES

Serial Prefix Change

1113A-1049A I
1048A-1040A I, II
1039A-1025A I, II, III
1024A-1017A I, II, III, IV
1016A-926 I thru V
925-845 I thru VI
844 and Below I thru VII

8-4. CHANGE I
8-5. COLOR SCHEME. Page 1-3, Figure 1-4, change trim

to Light Gray.

Page 2-2, Figure 2-1, change Rack Mount Brackets part no. to
07035-00490.

Page 6-3, Table 6-1, change J-601 part no. to 8120-3148.
Page 6-6, Table 6-2, Spare Parts, change the following items:

Power Cord, 8120-1348; Panel - Side - RH & LH, 07035­00071; Panel - Front and Rear, 07035-00061; Rear Hood Assy

- Stnd, 07035-62570; Rear Hood Assy - Metric, 07035-62571.
Page 6-11, Figure 6-2, items 47 and 48 part no.'s are:

47 Block, Pen Arm, 07034-60320; 48 Pen Scale Assy - Eng,
07034-60210 and Pen Scale Assy - Met - 07034-60200

Page 6-9, Figure 6-1, make the following changes:
Pen Scale - Eng, 07034-60210; Pen Scale - Met, 07034­60200; Rear Hood Assy - Eng, 07035-62570; Rear Hood - Met,
07035-62571; Panel Rear, 07035-00061; Panel RH, 07035­00071; Rear Corner - RH, 07035-40030; Front Corner - RH,
07035-20150; Rear Corner - LH, 07035-40040; Panel - Front,
07035-00061; Front Corner - LH, 07035-40021; and Panel ­LH, 07035-00071.

Page 7-9, Figure 7-2, use the following Component ID
illustration:

8-1

TM 11-6625-2850-14&P

FIGURE 8-1. COMPONENT IDENTIFICATION - CIRCUIT BOARD

8-2

8-6. CHANGE II
8-7. IEC. Page. All photos and illustrations of Front Panel will appear as shown:

FIGURE 8-2. CONTROL PANELS - MODEL 7035B AND 7035B-001

Delete IEC from Rear Connector.
8-8. CHANGE III
8-9. IEC. Page 6-3, Table 6-1, change DS601 and F601 to read:

DS601 1450-0123 Indicator Light 08717 859-R-6

F601 2110-0063 Fuse, 0.75A, 2A 250v 75915 312.750

1400-0085 Holder - Fuse 75915 342004

Page 6-3, Table 6-1, change J601 and P601 to read:

J601 8120-0078 Power Cord 0903 KH-4147

P601 12 51-0148 Connector, AC Power 87930 1065-1

Page 6-5, Table 6-1, change S601 to read:

S601 3101-0033 Switch, Slide (Power Conversion) 79727 6510C

Sloan

Littlefuse

Littlefuse

Belden

Tower Mfg

Continental

Page 6-6, Table 6-2, change Power Cord to read:

8120-0078 Power Cord 70903 KHS-7041

Belden Corp

8-3

Page 6-7, Table 6-3, change DS 601 and F601 to read:

DS601 1450-0123 Indicator Light 08717 859-R-6

F601 2110-0063 Fuse, 0.75A, 2A 250V 75915 312.750

1400-0085 Holder -Fuse 75915 342004

Page 7-9, Figure 7-3, make the following change to the schematic:

FIGURE 8-3. IEC POWER CONNECTION

Shielded 4-conductor cable and 3 additional color coded wires (white/blue, black and yellow) are replaced by a
shielded 7-conductor cable assembly. Pre-IEC receptacle for ac power connector also used.

Sloan

Littlefuse

Littlefuse

8-10. CHANGE IV
8-11. CARRIAGE ARM. Page 6-11, Figure 6-2, Legend,

delete, item 29, delete part no. for terminal
8-12. CHANGE V
8-13. PEN ASSEMBLY. Page 1-4, Table 1-2, should

include the following: Slidewire cleaner, slidewire lubricant, 2
pens, 1 btl green ink, 1 btl red ink, ink filling, syringe, rear

mating connector, appropriate graph paper, power cord (7.5 ft),
rack mounting brackets, dust cover, instruction manual.

Page 3-4, paragraph 3-34, 3-35, and Figure 3-3, replace with:

3-34. INSTALL AN INK PEN
3-35. Use a hypodermic syringe; fill reservoir just

short of full. Force ink into the pen tip by fully
inserting the syringe into the filler opening and
squeeze gently. See Figure 8-4.

8-4

FIGURE 8-4. FILLING INK PEN

Page 4-1, add new paragraphs 4-6A and 4-6B to read:

4-6A. PEN SYSTEM
4-6B. The pen assembly consists of a drum type

reservoir resting in a pivot mount which moves along
the carriage arm. A rigid capillary tube feedline leads
from the reservoir to the pen point. Because of the
capillary process, rack mounted (vertical) models
write equally well as the table models. The pen
should never be allowed to run dry.

ink stops flowing. Pen assemblies should be cleaned
thoroughly every two to four weeks. Clean by soaking
in alcohol or hot water. Clogging during operation
may be cleared by one or more of the following steps:

a. Using the furnished syringe, apply air pressure to

the reservoir's ink filler hole.
b. Soak pen assembly in alcohol or hot water.
c. Internally clean tip by inserting the stiff wire

supplied in accessory kit.
d. Prior to extended storage, flush and clean pen.

Page 5-3, add new paragraphs 5-18A and 5-18B to read:

5-18A. PEN MAINTENANCE
5-18B. Pen writing failures may be caused by dried

ink, sediment, air bubbles in feed line, or general
neglect. Dirt and ink sediment cause the most
difficulty. Dried ink forms brittle crust particles which,
together with dirt, build up in the supply line until the

17999-09423 Syringe (Pen filler) H-P 17999-09473

9260-0128 Ink, Red
9260-0127 Ink, Blue

9270-1006 Chart Paper, Standard (heavy) Gubelman H-10070/A
9270-1007 Chart Paper, Standard (light) Gubelman L-10070/A
9270-1023 Chart Paper, Metric (heavy) Gubelman

9270-1027 Chart Paper, Metric (light) Gubelman
07035-80630 Pen Assy H-P 07035-80630
07035-81030 Pen Accessory Kit H-P 07035-81030

5950-2587 Maintenance brochure H-P 5950-2587

Page 6-7, Table 6-3, Spare Parts, change K401 to:

07035-60140 Solenoid, Pen Lift H-P 07035-60140
07035-60120 Plunger Assy, Solenoid H-P 07035-60120

CAUTION Care must be taken not to touch pen

tip with fingers or any greasy
substance.

Page 6-6, Table 6-2, Mechanical, Electric, add 17999-15126,
Pen Cleaning Wire, H-P, 17999-15126.

Page 6-6, Table 6-2, Accessory Kit, Paper, Ink, change to read
as follows:

Page 6-7, Table 6-3, Spare Parts, delete Pen Holder, add:

07035-80630 Pen Assembly H-P 07035-80630

Page 6-10, Figure 6-2 (Illustration) is changed as shown in Figure 8-5.
Page 6-11, Figure 6-2 (Legend) make the following changes:

12 14600722 Spring, Pen Lift Superior Spring
47 07035-41820 Block, Pen Arm H-P
48 0703560185 Pen Scale Assy - Blank Scale H-P

07035-60186 Pen Scale Assy - English Scale H-P
07035-60250 Pen Scale Assy - Metric Scale H-P

54 07035-61120 Pen Holder Assy (all Serial Prefixes H-P

before 803)

07035-60070 Pen Holder Assy (Serial Prefix 803 and H-P

later without disposable pen)
56 07035-61410 Pen Lift Assy H-P
58 07035-60140 Solenoid Assy (Below S/P 826 requires H-P

index point 07005-00730)
60 07035-62210 Plunger, Solenoid Assy H-P
61 07035-80630 Pen Assy H-P

8-5

TM 11-6625-2850-14&P

FIGURE 8-5. EXPLODED VIEW - CARRIAGE ARM

8-6

Page 6-9, Figure 6-1, change PEN SCALE part no.'s to:

BLANK 07035-60185 ENGLISH 07035-60186 METRIC 07035-60250

Page 7-7, Table 7-1, new item 33 to read:

33. Pen won't write a. Pen tip clogged. a. See paragraph 5-18B.

b. Pen reservoir empty. b. Fill with ink (See Figure 3-3.).
8-14. CHANGE VI
8-15. X CAL. Page 6-5, Table 6-1, change R-225 to:

R-225 0698-3250 Resistor, Mtl Flm, 1.71k 1%, 1/8W Int'l Resist. CEA T-2.

Page 7-9, Figure 7-3, X AXIS BLOCK, change value of Page 6-11, Figure 6-2 (Legend), change item 48 to read:
R225 to 1.71k.

8-16. CHANGE VII 48 0035-60180 Pen Scale Assy - Blank

07035-60181 Pen Scale Assy - English
8-17. COLOR SCHEME. Page 1-3, Figure 1-4, 07035-60182 Pen Scale Assy - Metric
change trim to aluminum. Page 6-9, Figure 6-1, change the following:

PEN SCALE BLANK 07035-60180; ENGLISH 07035-60181; METRIC 07035-60182
REAR HOOD ASSY ENGLISH 07035-60020; METRIC 07035-60021

8-7(8-8 blank)