Racal Instruments 9901 User manual

9901
Universal Counter-Timer
1978
THE QUEEN'S AVMRO
FOR TECHNOLOQICAL ACHIEVEIWNT
TO DACAL DANA INSTRUMENTS LTD.
UX3BSB
The Electronics Group
Racal-Dana Instruments Limited Duke Street, Windsor, Berks, England
Prepared by Central Handbooks Department, Racal Group Services Limited.
Printed in England Ref. WOH 6201 Issue 7.2.79-150

LETHAL WARNING
Voltages within this equipment are sufficiently
high to endanger life.
Covers are NOT to be removed except by persons
qualified and authorised to do so and these
persons should always take extreme care
once the covers have been removed.
Resuscitation instructions are given overleaf.

FIRST AID in case of Electric Shock
1. Lay victim on his back.
2. Clear victim’s mouth and throat.
3. Tilt victim’s head back as far as
possible and raise his head.
Have someone else send for aDoctor
Keep patient warm and loosen his clothing
4. Pinch victim’s nostrils.
5. Take adeep breath.
6. Cover the victim’s mouth with yours
and blow, watching his chest rise.
Note: Blow forcefully into adults, but
gently into children.
7. Move your face away to allow victim
to breathe out, watching his chest fall.
8. Repeat first five to ten breaths at a
rapid rate; thereafter, take one breath
every three to five seconds.
9. Keep victim’s head back as far as
possible all the time.
DO NOT Give liquids
until patient is conscious

[WOH 6201 Universal Counter Timer 9901

CONTENTS
Page
FRONTISPIECE
SECTION 1TECHNICAL SPECIFICATION AND
SUPPLEMENTARY DATA
SECTION 2DESCRIPTION OPERATION AND MAINTENANCE
CHAPTER 1GENERAL INSTRUCTIONS 1-1
CHAPTER 2OPERATING INSTRUCTIONS
Power Supply 2-1
Frequency Measurement 2-1
Period Measurement 2-2
Time Interval (Tl and Tl Average) 2-3
Ratio 2-4
Totalize 2-5
Description of Controls 2-6
Indicators 2-9
Rear Panel Items 2-9
CHAPTER 3PRINCIPLES OF OPERATION
The CDI Chip 3-1
Basic Frequency Meter 3-1
General Circuit Functions 3-2
Dynamic Display System 3-2
Self Check 3-3
Average Period Measurement 3-3
Time Interval (Single and Double Line) 3-4
Time Interval Average 3-5
Ratio 3-6
Totalize 3-7
Control Sequence 3-8
Display and Data Output System
Resistor Arrays 3-9
CHAPTER 4TECHNICAL DESCRIPTION
Introduction 4-1
Function and Range Switching 4-1
Control Codes 4-1
Frequency Auto Mode 4-1
9901 Vol. 2Contents (1)

CONTENTS (Confinued)
Data Latch/Unlatch. Normal/Hold and Reset
Page
4-3
Channel 'A' Input 4-3
AC Amplifier 4-3
DC Amplifiers 4-4
'B' Channel DC Amplifier 4-4
Bounce Protection 4-4
'A' Channel DC Amplifier 4-5
Check Mode 4-5
Slope Selection 4-5
Manual Start/Stop 4-6
Data Output and Display System 4-6
Multiplex Readout and Display 4-6
Decimal Point and Overflow Decode 4-6
Gate Indicator LP2 4-7
Display Time and Reset Generator 4-7
Display Time Circuit 4-7
Reset Pulse 4-7
Manual Reset 4-8
External Reset 4-8
Segment Check 4-8
Frequency Standard 4-8
Standard Oscillator Assembly 19-0834 4-8
Optional Oscillator 4-8
Frequency Doubler 4-9
1MHz Reference Output 4-9
External Standard Input 4-9
Power Supply 4-9
+5V Stabilization 4-9
-5V Stabilization 4-9
On/Off Switching 4-10
CDI Chip 2V Supply 4-10
CHAPTERS MAINTENANCE
Test Equipment Required 5-1
Removal of Covers 5-2
Transformer Voltage Selection 5-2
Voltage Selection Diagram 5-3
Fuses 5-4
Power Lead 5-4
Power Supply Check 5-4
9901 Vol. Contents (2)

CONTENTS (Conti nued)
Page
Performance Tests and Calibration 5-5
Segment, Decimal Point and Self Check 5-5
Sensitivity Checks: Input 'A' 5-6
Time Interval Single Line Check 5--7
Time Interval Double Line Check 5-8
Time Interval Average Check 5-9
Ratio Check 5-9
Totalize Check 5-10
Frequency Standard Calibration 5-11
Dismantling 5-12
Removal of Display PCB 5-12
Removal of Main PCB 5-13
Replacement of Main PCB 5-13
Fitting Optional Frequency Standard Unit 5-14
Fig. No.
IN TEXT ILLUSTRATIONS
Page
A1 Data Sequence Diagram Tech. Spec.
3.1 Basic Frequency Meter 3-1
3.2 Period Measurement 3-3
3.3 Time Interval Measurement 3-4
3.4 Time Interval Average Measurement 3-5
3.5 Ratio Measurement 3-6
3.6 Totalizing 3-7
3.7 Control Sequence Diagram 3-8
3.8 Multiplex Display System 3-9
3.9 D. I. L. Resistor Array 3-10
5.1 Voltage Selection Diagram 5-3
Table No.
LIST OF TABLES
Page
1Data Output Socket Tech. Spec.
2Function Information
1
Tech .Spec
.
3Time Base Selection
4Function Information 4-2
5Time Base Selection 4-2
9901 Vol. 2Contents (3)

LIST OF TABLES (Continued)
Table No. Page
6Test Equipment Required 5-1
7Self Check Readout 5-5
8Input 'A' Sensitivity Check 5-6
9Time Interval Single Line Check 5-8
SECTION 3PARTS LISTS, COMPONENT LAYOUTS AND CIRCUIT DIAGRAMS
Component Layout; Display Assembly Fig. 1
Parts List 1; Display Assembly
Circuit and Layout: Oscillator PCB Assembly Fig. 2
Parts List 2; c5sci Ilator PCB Assembly
Parts List 3: Chassis, Front and Rear
Panel Assemblies
Parts List 4a and 4b; Main PCB Assembly
Component Layout; Main PCB Assembly Fig. 3
Overall Circuit: 9901 Fig. 4
SECTION 4APPENDICES AND CHANGE INFORMATION
APPENDIX 1: SERIAL TO PARALLEL INTERFACE UNIT
9901 Vol. 2Contents (4)

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