Tektronix 1503 User manual

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Tektronix,
Inc.
P.O.
Box
500
Beaverton,
Oregon
97077
070-1865-01
Product Group
27
COMMITTED
TO
EXCELLENCE
PLEASE CHECK FOR CHANGE INFORMATION.
AT
THE REAR OF THIS MANUAL.
1503
TIME
DOMAIN
REFLECTOMETER
INSTRUCTION
MANUAL
Serial
Number
______
_
First Printing OCT 1975
Revised
AUG
1982

Copyright ©1975, 1980Tektronix,Inc. All rightsreserved.
Contents of this publication may not
be reproduced in
anyform withoutthewritten permission ofTektronix, Inc.
Products of Tektronix, Inc. and its subsidiaries are
covered by U.S. and
foreign patents and/or pending
patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and
~ are
registered trademarks of Tektronix, Inc. TELEQUI
P-
MENT is a registered trademark of Tektronix U.K.
Limited.
Printed in U.S.A. Specification and price change
privileges are reserved.
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TABLE OF CONTENTS
Page
LIST
OF ILLUSTRATIONS . . . . . . . . . . . . . . . . . ii
OPERATORS SAFETY SUMMARY . . . . . . . . • . . . iv
SERVICE SAFETY SUMMARY . . . . . . . . . . . . . . . v
Section 1 SPECIFICATION . . . . . . . . . . . . . . .
1-1
Section 2 OPERATING INSTRUCTIONS . . . . . . 2-1
I WARNING I
THE FOLLOWING SERVICE INSTRUCTIONS ARE FOR
USE
BY QUALIFIED PERSONNEL ONLY. TO AVOID
PERSONAL INJURY, DO NOT PERFORM ANY SER-
VICING OTHER THAN
THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO.
@
Section 3
Section 4
Section 5
Section 6
Section 7
Section 8
Section 9
THEORY
OF OPERATION
........
CALIBRATION PROCEDURE ......
Performance Check
...........
Adjustment Procedure
.........
MAINTENANCE ................
OPTIONS ....................
REPLACEABLE ELECTRICAL PARTS
DIAGRAMS AND ILLUSTRATIONS ..
REPLACEABLE MECHANICAL PARTS
1503
Page
3-1
4-1
4-2
4-4
5-1
6-1
7-1
8-1
9-1

1503
Fig.
No.
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
ii
LIST
OF
ILLUSTRATIONS (
1503 Time Domain Reflectometer
Page
2-1
Battery connector
polarity.
. . . . . . . . . . 2-2
Front panel controls . . . . . . . . . . . . . . . 2-3
Test pulse at reference line . . . . . . . . . . 2-4
TDR display
of
RL
vs
Zo
. . . . . . . . . . . . 2-7
X-Y
Output
Module strap . . . . . . . . . . . 2-7
Open
Tip
and Ring . . . . . . . . . . . . . . . . 2-9
Loading Coil . . . . . . . . . . . . . . . . . . . . 2-9
Shorted
tip
and ring
...............
2-10
Building-out
network
..............
2-10
67-ohm splice at 4000
feet.
. . . . . . . . . . 2-11
Split and re-split pair . . . . . . . . . . . . . . 2-12
Bridge
top
at 4000 feet . . . . . . . . . . . . . 2-13
Simplified Block diagram . . . . . . . . . . .
3-1
Sampling diagram
................
3-2
Timing
diagram . . . . . . . . . . . . . . . . . . 3-4
Sampling
Circuit
timing
. . . . . . . . . . . . 3-7
Functional
block
diagram of
the
Slow Ramp
Generator . . . . . . . . . . . . . . . . . . . . . . 3-8
Block diagram
of
1503 Power Supply
...
3-10
Chart Recorder
logic
..............
3-12
X-Y
Output
Module strap
...........
3-13
Power Supply
testpoints
and adjustment
location . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Sampling Efficiency Pulse . . . . . . . . . . . 4-7
First
Blow-by
Compensation Adjustments 4-8
Second
Blow-by
Compensation
Adjustments . . . . . . . . . . . . . . . . . . . . . 4-8
Fast Ramp test
point.
. . . . . . . . . . . . . . 4-9
External Calibration connection
.......
4-10
Fast Ramp test
point.
. . . . . . . . . . . . . . 4-11
External Calibration connection . . . . . . . 4-12
X-Y
Output
Module strap . . . . . . . . . . . 4-13
DC protection
link
location . . . . . . . . . . 5-2
Transistor and IC lead configuration . . . 5-3
Rear view
of
the HV board . . . . . . . . . . 5-4
Power Transformer
wiring
. . . . . . . . . . . 5-5
Subpanel, Identification
of
Parts . . . . . . 5-7
Rubber Seals, Edge Sealing
for
Subpanel 5-8
Detail
of
Implosion Shield Sealing . . . . . 5-8
Front Panel, Identification
of
Parts
for
Assembly Steps 8
through
26
. . . . . . . . 5-9
Fig.
No.
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
5-27
5-28
5-29
5-30
5-31
5-32
5-33
5-34
5-35
5-36
5-37
5-38
5-39
Page
Detail
of
Plug-in Compartment Seal . . . . 5-10
Detail
of
BNC
Connector
and Washer . . 5-10
Detail
of
Pushbuttons and Their Shafts 5-10
Detail
of
Subpanel Screwhole Sealing
..
5-11
Detail
of
Fuseholder Installation
......
5-11
Detail
of
Fuseholder Caps
...........
5-12
Application
of
Sealant
to
Battery Meter 5-12
Alignment
of
Battery Meter . . . . . . . . . . 5-12
Application
of
Sealant
to
FOCUS and
INTENSITY Controls
..............
5-12
Application
of
Sealant
to
FINE Control
Bushing
........................
5-13
Application
of
Sealant
to
Fl
NE Control Nut 5-13
Installation
of
Distance Meter
........
5-13
Application
of
Sealant
to
ZERO
REFERENCE
Control
Bushing . . . . . . . . 5-14
Application
of
Sealant
to
ZERO
REFERENCE Control Nut
...........
5-14
Application
of
Sealant
to
RECORD Toggle-
(
switch Bushing
.................
. 5-14
Application
of
Sealant
to
RECORD Toggle-
switch
Nut
.....................
. 5-15
Installation
of
Rubber Cap-seal on
RECORD
toggle-switch.
. . . . . . . . . . . . 5-15
Application
of
Sealant
to
the
Q-dB
SET
Control Bushing . . . . . . . . . . . . . . . . . . 5-15
Detail Showing Lubrication and Sealing
for
the Variable Resistor. ; . . . . . . . . . . . . . 5-15
Lubrication
of
the
0-rings
and Sealing
for
the Cam-switches . . . . . . . . . . . . . . . . . 5-16
Installation
of
the
POWER SWITCH
....
5-16
Lubrication
of
POSITION Control Knobs 5-17
Installation
of
Knob on Shaft . . . . . . . . . 5-17
Lubrication
of
ZERO REFERENCE Knob 5-17
Installation of Knob on ZERO REFERENCE
Control . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Lubrication
of
FOCUS and INTENSITY
Control Knobs
...................
5-18
Sealing
of
Battery Pack Screwholes
....
5-18
Application
of
Dielectric
Type
Compound 5-18
Detail
of
Front Panel Jacks
..........
5-19
Detail
of
X-Y
Module
Thumbscrews
....
5-19 (
Sealing of Latch Assembly Screwholes. . 5-20 ·
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1503
LIST OF ILLUSTRATIONS (cont)
Fig.
No. Page
Option
1-1 Front-panel controls . . . . . . . . . . . . . . . 6-1
Option
1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Option
1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
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iii

1503
OPERATORS SAFETY SUMMARY
The general safety information in this part of the summary
is
for both operating and servicing personnel. Specific
warnings and cautions will be found
throughout the
manual where they apply, but may not appear in this
summary.
TERMS
In This Manual
CAUTION statements identifyconditions or practicesthat
could resultindamage to theequi pr:nent or otherproperty.
WARNING statements identify conditions or practices
that could result in personal
injury or loss of life.
As Marked on Equipment
CAUTION indicates a personal InJUry hazard not im-
mediately accessible as one reads the marking, or a
hazard
to property including the equipment itself.
DANGER indicates a personal
injury hazard immediately
accessible
as one reads the marking.
SYMBOLS
In This Manual
This symbol indicates where applicable
cautionary
or other information is 'to be
found.
As Marked on Equipment
~ DANGER -High voltage.
@ Protective ground (earth) terminal.
_A ATTENTION- refer to manual.
Power Source
This product is intended to operate from a power source
that will not apply more than 250 volts rms between the
iv
supply conductors or between either supply conductor
and ground. A protective
ground connection bywayof the
grounding conductor in the power cord is essential for
safe operation.
Grounding the Product
This product is grounded through the grounding conduc-
tor of the power cord. To avoid electrical shock, plug the
power cord into a properly wired receptacle before
connecting to the product input or output terminals. A.
protective ground connection by way of the grounding
conductor in the power cord is essential
for safe opera-
tion.
Danger Arising From Loss of Ground
Upon loss of the protective-ground connection, all
accessible conductive parts (including knobs and con-
trols that may appear
to be insulating) can render an
electric shock.
Use the Proper Power Cord
Use only the power cord and connectorspecified for your
product.
Refer cord and connector changes to qualified service
personnel.
Use the Proper Fuse
To avoid fire hazard, use only the fuse of correct type,
voltage rating and current rating as specified in the parts
list
for your product.
Refer fuse replacement
to qualified service personnel.
Do Not Remove Covers or Panels
To avoid personal injury, do not remove the product
covers or panels. Do not operate
the product without the
covers and panels properly installed.
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1503
SERVICE SAFETY SUMMARY
FOR
QUALIFIED
SERVICE
PERSONNEL
ONLY
Refer a/so
to
the
preceding
Operators Safety Summary.
Do Not Service Alone
Do not perform internal service or adjustment of this
product unless another person capable of rendering first
aid and resuscitation is present.
Use Care When Servicing With Power On
Dangerous voltages exist at several points in
this
product.
To avoid personal injury,
do
not touch exposed connec-
tions and components while power is on.
@
Disconnect power before removing protective panels,
soldering, or replacing components.
Power Source
This product is intended
to
operate from a power source
that will not apply more than 250 volts rms between the
supply conductors
or
between either supply conductor
and ground. A protective
ground
connection
byway
ofthe
grounding conductor in the power cord is essential
for
safe operation.
v

1503
·
1865-01A
•
1503
Time
Domain
Reflectometer.
vi
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Section
1-1503
SPECIFICATION
General Information
The TEKTRONIX 1503 is a portable Time Domain
Reflectometer
which
uses pulse techniques
to
test cables
and provides a visual
display
of cable faults. The test
pulses are transmitted via
the
CABLE
output
jack. Reflec-
tions
are received at
the
same
jack
and displayed on the
cathode-ray
tube
(crt).
NOTE
All
distances are shown in feet followed
by
metresin
parenthesis.
Metric
units
are not
direct conversions
from the measurements shown in teet,
but
represent
the
calibrated
ranges
of
the
metric
option
1503.
Multiplier
settings
tor
the
metric
options are
in-
dicated
in
the same manner.
Calibrated distance
controls
allow
an
operator
to
examine
up
to
50,000 feet
(1
0,000 metres) of cable.
Up
to
7,500 feet
(1
,500 metres)
of
cable can be examined
with
the
multiplier
control
at X10 (X1) from
which
50
to
5000
feet (10 metres
to
1000 metres) can be displayed across
the 10-division horizontal (X-axis) crt scale
with
an
additional 0
to
2500 feet (0
to
500 metres) of distance
covered by
the
DISTANCE dial.
Up
to
50,000 feet (10,000
metres)
of
cable can be examined when the
multiplier
control is at
X1
00
(X1
0)
of
which
500
to
50,000 feet
(1
00
to
10,000 metres) can be examined across the crt face. With
the FEET/DIV (METRES/DIV) control set at
50,
('100)
and
X1
00
(X1
0)
up
to
50,000 feet
(1
0,000 metres) of cable can
be
displayed on
the
crt
screen, but in this position
the
DISTANCE dial is disabled. The horizontal crt scale is
calibrated in distance units from 5 feet
(1
metre) per
division
to
5000 feet
(1
000 metres) per division in a1-2.5-5
sequence. Distance calibration accuracy on
the
crt
scale
is
within
±2%
of
indication.
There are
three
externally selectable
dielectric
con-
stants.
Two
of
these are calibrated
for
foamed
polyethylene (FOAM POLY) and solid polyethylene
(SOLID POLY). The
third
is obtained by
"default"
con-
ditions; both pushbuttons depressed or both pushbuttons
released. When both pushbuttons (FOAM POLY and
SOLID POLY) are depressed
or
released,
the
effective
dielectric constant is variable, being
controlled
by
a
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screwdriver adjustment labeled "VAR". The
fully
clockwise position
of
the
"VAR"
control setsthe dielectric
constant
for
air.
Vertical (Y-axis) deflection of
the
crt beam is
propor-
tional
to
the amplitude of
the
reflected signal. The vertical
scale is a linear representation
of
the
return pulse and is
ordinarily
calibrated so that
two
divisions represent
"0
dB"
when the reference level is set
to
"0
dB". The dB
reference level isselectablein 7calibrated stepsfrom 0
dB
to
60
dB
plus a 0
to
18
dB
vernier adjustment.
The transmitted pulse is an impulse signal of ap-
proximately 5 V
into
a
50
0,
75
0,
93
0,
or
125 0 load.
Half-sine shaped pulse
durations
of
10
ns,
100
ns,
or
1000 ns are selectablefrom
the
front
panel. Durations are
measured at the half
amplitude
points.
The 1503 plug-in
compartment
will accept either
the
X-
V
Output
Module
or
the
TEKTRONIX
Y-T Chart Recorder.
The X-Y
Output
Module
is a standard accessory
for
the
1503 and provides
an
interface
for
an
X-Y recorder. The
TEKTRONIXY-T Chart Recorderis an optional accessory.
This recorder uses a heated stylus
to
record on 4
em
wide,
heat-sensitive chart paper. The chart recording length
represents the entire crt screen and is controlled by
the
1503.
The 1503 is a ruggedized portable instrument that can
be used in the field
as
well as
in
the
laboratory. The 1503
meets requirements
for
a
Type
Ill, Class
3,
Style A
instrument
as
specified in MIL-T-28800. The 1503 has a
ruggedized case that provides protection whentheinstru-
ment is stored in exposed areas. When
the
instrument is
not being used,
the
accessories,
including
the
Operators
manual, may
be
packed
in
the
instrument cover and
latched
tightly
on the
front
of
the
instrument. Table
1-1
indicates which accessories
may
be placed in the cover
of
the
1503.
The characteristics given in Table 1-2 apply over an
ambient temperature range
from
-15°C
to
+55°C
after
the instrument has been calibrated at
+25°
C,
±5°
C.
1-1

Specification-1503
Characteristics
Impulse
Width
Accuracy
Amplitude
Terminated
Unterminated
Shape
Termination
Jitter
Graticule Deflection
Deflection
Range
Accuracy
Deflection Reference
Accuracy
Variable
1-2
Table 1-1
STANDARD ACCESSORIES FOR THE 1503
Accessory Tektronix Part Number
2 Replacement Fuses 159-0032-00
(ac-tor front panel) (for 115 Vac)
or
159-0029-00
(for
230 Vac)
1 Power Cord 161-0066-00
1 Viewino Hood 016-0297-00
1
50 0 BNC Terminator 011-0123-00
1 X-V
Output Module 016-0606-00
1 Filter, Mesh (crt) 378-0055-00
1 Operators Handbook 070-1864-00
1 Instruction Manual 070-1865-00
1 Cable Assembly 012-0671-00
1 Calculator, 003-0700-01
TOR Cable Tester
Table 1-2
ELECTRICAL CHARACTERISTICS
Performance Requirements Supplemental Information
Selectable: 10 ns, 100 ns, 1000 ns Measured at half amplitude point.
±20%
5 v±20%
10 v±20%
1/2 sine
50 0, 75 0, 93 0 ±1%. 125 0 ±3% ..
0.2 division maximum At 5 ft/div (1 m/div)
+6 to -18 dB From deflection reference; linear
scale on gratiucle. 0
dB=2 div,
displayed signal
~0.1 div.
±3%
0 to 60 dB 7 steps, 10 dB increments.
±0.1 dB
Oto18dB Additive to step increments.
Fully clockwise is
18 dB ±2.0 dB.
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