Tektronix 323 Service manual

OPERATORS
HANDBOOK
TYPE 323
OSCILLOSCOPE
This handbook is a reference document on
basic characteristics, operation, performance
check, maintenance, and applications. Com
plete and detailed information is provided in
the standard manual supplied with the
instrument.
070-1155-00 1270

CONTENTS
Page
Specifications
Power Requirements 4
Power Pack Replacement 5
Battery Care 6
Fuse Location 9
Function of Controls and Connectors 2
Performance Check and Familiarization 8
Measurement Technique 26
Triggering 28
Single Sweep Operation 3
Internal External Sweep Operation 32
Selecting Sweep Rate 35
Signal Application to Vertical Input 35
How to Measure Voltages 37
Time Measurement 42
Frequency Measurement 43
Phase Measurement 44
How to Use External Blanking 46 “
Common Operational Errors 46
Copyri ht © 1970 by Tektronix, Inc.,
Beaverton, Ore on. Printed in the United
States of America. All ri hts reserved. Con
tents of this publication may not be repro
duced without permission of the copyri ht
owner.

ABRIDGED SPECIFICATIONS
(Electrical)
Complete updated specifications are provided in
the Instruction manual.
Characteristic Performance Requirement
Deflection Factor
Accuracy Within 3% of VOLTS/DIV
indication.
nput R & C ±2%, 45 pF ±4 pF.
Bandwidth/Rise-
time
XI Gain At least 4 MHz (90 ns)
X 0 Gain At least 2.75 MHz ( 30 ns)
Low Frequency
(—3 dB) Point,
AC Coupled
2 Hz or less
Maximum Input
Voltage 500 V (DC + peak AC) with or
without probe
Step Response
Aberrations Within 3% (total peak to peak)
Overload
Recovery Within /is after a signal
change, at the VERT INPUT,
of ±30 divisions of deflection.
© 323 1

Characteristic Performance Requirement
Trigger Sensi
tivity
nternal 0.3 div. to 400 kHz increasing
to 0.75 div. for 4 MHz
External 75 mV to 400 kHz increasing
to 90 mV for 4 MHz. (Signal
applied to EXT TRIGGER IN
PUT connector, ATTEN set to
IX position. Increase signal
level for 0X position of the
ATTEN switch.)
AC Coupled,
including AUTO Sensitivity decreases sharply below 30 Hz
ACLF REJ
Mode Sensitivity decreases sharply
below 30 kHz.
External Trigger
nput R & C M£2 ±2%, 62 pF ±4 pF
Maximum Input
Voltage 300 V (DC + peak AC)
Horizontal Sweep
Timing Accuracy
(with VARiable
control in CAL
position)
Unmagnified 5 jiis/div to 0.2 s/div, within
3%
0.5 s/div to s/div, within 4%
®
2323

Characteristic Performance Requirement
Magnified 2 jus/div to 20 ms/div., within
4%
0.5 jus/div, .0 jus/div. 50 ms/
div, and 0. s/div, within 5%
External Horizon
tal nput Deflec
tion Factor
200-300 mV/div.
Square Wave
Calibrator
Amplitude 0.5 V, ±2% (peak to peak).
Frequency Approximately 850 Hz
Risetime
(leading edge) 2 jus or less
External Blanking
Frequency
Range DC to 00 kHz
Voltage Level Blanks at approximately +5 V
to +20 V
Maximum Input
Level 50 V (DC + peak AC)
nput Resistance Approximately 00 k!TL
323 3

Characteristic Performance Requirement
Power Supply
Battery Pack Six NiCdC Cells
Operating Time 3 to 7 hours, depending on
display intensity, amplitude,
and input signal frequency.
Charge Time
(Full Charge) Approximately 6 hours
External DC
Supply 6 V to 6 V at 4.5 watts maxi
mum
Line Voltage
(to battery pack)
Range 90 V to 36 V AC
or
80 V to 272 VAC
Frequency 48 Hz to 400 Hz
POWER SOURCE REQUIREMENTS
The instrument requires an internal power pack,
with NiCd batteries, or an external (+6 V to + 6
V) DC source for power. A three position switch to
the power pack selects either power source, and
the battery charge rate when AC power is applied.
The instrument will not operate from an AC power
source if the battery is missing or defective.
4323

Either 5 V or 230 V nominal AC line source
can be used for AC powered operation. Connect
the AC source to the battery pack with the power
cord, then switch power source switch to AC/
BATT position. Refer to Figs. , 2, and 3 for
power pack removal, fuse location and 5 V or
230 V AC hook-up instructions.
The battery can be charged with the power pack
out of the instrument if desired. Extra power packs
can, therefore, be charged to serve as spares. See
Battery Care for instructions.
To operate the 323 from an external DC power
source; set the power pack source switch to EXT
DC position, connect a +6 to + 6 volt DC source
to the banana jacks above the line cord receptacle
(observe polarity markings) and switch the front
panel POWER switch to ON.
POWER PACK REPLACEMENT
WARNING
The power pack battery can deliver enough
energy, if short circuited by such items as
rings and watch bands, to produce severe
burns. Switch the power selector switch to
EXT DC position to reduce the number of
points that have battery voltage or remove
rings and other items before handling the
power pack.
323 5

The 323 will not operate from the internal
battery or an AC source if the selector switch is
left in EXT DC position. The battery will, how
ever, charge at full charge rate if AC Power is
applied. Fig. illustrates removal and replacement
procedure.
BATTERY CARE
The power pack uses six sealed NiCd cells con
nected in series for the battery. These cells require
little maintenance, have high discharge rate, accept
long term overcharging and operate over a rela
tively wide range of temperature. If properly cared
for, you can expect about 500 to 600 charge/
discharge cycles before their capacity drops to
about 80% of specified value. Some of the more
important battery characteristics and care are
described below so maximum operating time
between recharge cycles can be obtained.
SELF DISCHARGE is a continuous process as
long as the battery has any charge. The rate of self
discharge depends on ambient temperature, state
of charge, and impurities in the battery. Self
discharge at 45°C is approximately five times
greater than it is at 20°C. A fully charged NiCd cell
may lose 0% to 5% of full capacity during the
first 24 hour period. This discharge rate decreases
to about 0.68% per day or 0% to 5% per month
after the initial discharge. To obtain the maximum
6323

power / / Cover-securing
connection ' screw
A. Loosen securing screw and pull dust cover off.
B. Disconnect interconnecting power leads. Release securing
clamp.
AC Fuse location; pull
cover straight down to
expose fuse; align cover
d e te n ts and fuse
mounting base when re
placing cover.
C. Power pack.
Fig. . Removing the battery power pack.
323 7