HP HP-7035B User manual

TECHNICAL MANUAL
HEWLETT-PACKARD MODEL HP-7035B

Section Page
IINTRODUCTION ......................................... 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
Section Page
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
VMAINTENANCE, 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
LIST OF TABLES
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
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 Communications-
Electronics 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.
FIGURE 1-3. INSTRUMENT IDENTIFICATION
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.
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.
Input Resistance:
Range Input Resistance:
1 mV/in. (0.4 mV/cm) Potentiometric.
(essentially in-
finite 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.
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
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
1-24. 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.
1-25. 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.
1-32. 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
1-4

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)
FIGURE 1-8. TYPICAL DYNAMIC RESPONSE
1-6

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.
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 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.
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 Y-
axis (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

FIGURE 4-1. BLOCK DIAGRAM
FIGURE 4-2. DETAILED BLOCK DIAGRAM
4-2
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