Tektronix 549 User manual

I N S T R U C T I O N
M A N U A L
TYPE 549
STORAGE
OSCILLOSCOPE
Tektronix, Inc
S.W . M illikan Way • P. O. Box 500 • Beaverton, Oregon 97005 • Phone 6 -0161 • Cables:
070-0508-00
Tektrohix
266

WARRANTY
All Tektronix instruments are warranted
against defective materials and workman-
ship for one year. Tektronix transformers,
manufactured in our own plant, are war
ranted for the life of the instrument.
Any uestions with respect to the war
ranty mentioned above should be taken
up with your Tektronix Field Engineer.
Tektronix repair and replacement-part
service is geared directly to the field,
therefore all re uests for repairs and re-
placement parts should be directed to the
Tektronix Field Office or representative in
your area. This procedure will assure you
the fastest possible service. Please include
the instrument Type and Serial or Model
Number with all re uests for parts or
service.
Specifications and price change privi-
leges reserved.
Copyright © 1966 by Tektronix, Inc.,
Beaverton, Oregon. Printed in the United
States of America. All rights reserved.
Contents of this publication may not be
reproduced in any form without permission
of the copyright owner.

CONTENTS
Section 1Characteristics and Operating Features
Section 2 Operating Instructions
Section 3 Circuit Description
Section 4 Maintenance
Section 5 Performance Check
Section 6 Calibration
Parts Ordering Information
' ’ iAbbreviations and Symbols
Section 7 Electrical Paris List
Mechanical Parts List Information
Section 8Mechanical Parts List
Section 9Diagrams
Mechanical Parts List Illustrations
Accessories
Abbreviations and symbols used in this manual
are based on, or taken directly from, IEEE Stand
ard 260 "Standard Symbols for Units", MIL-STD-
12B and other standards of the electronics
industry. Change information, if any, is located
at the rear of this manual.
Type 5 9

TYPE 549 STORAGE OSCILLOSCOPE fast ¥v«it*m;
inn it. A*riG HCALt MftO»
OUAl ttACt WjO W Wl>
(UllM'd
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CHANNEL 2
CHANNEL 1
iNttir h o c io i infv< micra*
tt^rumn
Fig. 1-1. The T po 549 Storage Oscilloscope.
Type 549 ®

SECTION I
CHARACTERISTICS AND
OPERATING FEATURES
Introduction
The Type 5 9 Storage Oscilloscope is a laboratory instru
ment designed to operate with all Tektronix letter-series or
one-series plug-in units.
The cathode ray tube (T5 90) used in the Type 5 9 is a
direct view, bistable storage tube having a 6 X 10 cm dis
play area, divided into two 3 X 10 cm targets. The targets
are independently controlled for split screen applications.
An additional area which does not store is provided to the
left of the targets. This area functions as a locate zone in
single sweep store mode.
This instrument will perform to specifications in laboratory
environment with ambient temperature range between 0°
C to 50° C except as indicated. Warm-up time for rated
accuracies at +25° C ± 5 ° C is 20 minutes. Adequate
ventilation must be maintained, and a minimum two inch
clearance around the instrument is recommended.
Statements related to measurement capabilities of the
instrument with respect to voltage, time or frequency are
characteristics and are printed in bold type. Other features
are listed in regular type.
Characteristic Re uirement
or Feature
VERTICAL DEFLECTION SYSTEM
Fre uency Response DC to 30 MHz or more (at — 3
dB point).
Equivalent to a risetime of 12 ns or
less.
Input Deflection 100mV/cm ± 3 %
Factor
HORIZONTAL DEFLECTION SYSTEM
Time Base A
Sweep Rate Accuracy within ± 3 % of indi
cated rate in all calibrated step
positions.
Variable Range Sweep rate continuously variable
uncalibrated.
Time Base B
Sweep Rate
Sweep Length
X 5 Magnified
(Time Base A
and B)
Accuracy within ± 3 % of indi
cated rate in all calibrated step
positions.
Sweep length is adjustable from
cm or less to 10 cm or more.
Accuracy is within ± 2 % of the
sweep rate accuracy.
Characteristic Re uirement
or Feature
Enhanced Writing
Speed
Stored Resolution
Contrast Ratio
E ual to or greater than 5 cm/
μs.
Stored vertical resolution, 20 lines/
cm.
Contrast ratio at operating level
is equal to or greater than :1.
VARIABLE TIME DELAY
Delay Time Accuracy Accuracy is within ± 1 % of Time
Base B sweep rate accuracy. |±
2.0 minor divisions of the DELAY
TIM E MULIPLIER dial).
Multiplier Incremental
Linearity Incremental delay accuracy is ±
0.2% of total range.
Variable Time
Delay Jitter 1 part in 20,000 of the available
delay interval. (10 times B TIME/
CM setting).
NOTE
Stated accuracies apply only when the VARIABLE
control is set to the CAL position.
AMPLITUDE CALIBRATOR
Voltage Output Peak to peak amplitude accu
racy is within ± 2 % of indicated
amplitude when working into an
impedance of 1 MΩ or higher.
When working into a 50 Ω load,
in the 0.2 to 200 m Volt posi
tion, output amplitude is one-
half the indicated amplitude
±3%.
Current Output 5 mA ± 2 % .
Current Signal Output Provides a square wave of current
or DC.
Frequency 1 kHz ± 2 5 % , positive going
square wave with zero volt base-
line.
Rise Time Equal to or less than 1 µs.
STORAGE PERFORMANCE EXTERNAL HORIZONTAL AMPLIFIER
Writing Speed E ual to or greater than 0.5 cm/ Fre uency Response DC to 350 kHz at maximum gain
μµ s. (at — 3 dB point).
1-1

Characteristics— Type 549
Characteristic Re uirement
or Feature
Deflection Factor
1 x 0.2 V/cm maximum. (VARIABLE 1
10 control fully clockwise)
1 0 x 2V/cm maximum.
VARIABLE 1-10 control provides
variable attenuation of the input
signal of at least 10:1.
FRONT PANEL OUTPUT SIGNALS
VERT SIG OUT
SWEEP A
+ GATE A
+ GATE B
DLY’D TRIG
Output is 1.5 volts per centimeter
±20% of displayed deflection on
the CRT. Frequency response is DC
to 700 kHz (at the —3 dB point).
This is equivalent to a risetime of
1 µs or faster.
150 volts ± 1 0 volts increasing to
approximately 180 V ± 1 0 volts at
the faster sweep speeds and having
the same time duration as the A
sweep. Recommended load resist
ance equal to or greater than 100
ktl.
Within the range of 20 to 0 volts.
Positive going pulse with the base
line at zero volts. Time coincident
with the A sweep. Recommended
load resistance equal to or greater
than 5 kO.
Within the range of 20 to 0 volts.
Positive going pulse, baseline at
zero volts, time coincident with the
B sweep.
A positive going pulse 7 V ± 2 V
into a load equal to or greater
than 10 kΩ.. Pulse occurs at the
end of the delay period.
EXTERNAL SIGNAL CONNECTORS
Z Axis Modulation
CRT GRID An applied 20 volt peak-to-peak
signal from DC to 1 MHz will blank
or unblank the CRT. A 5 volt peak-
to-peak signal will produce notice
able modulation. Negative portion
of signal blanks CRT beam.
CRT CATHODE An applied 20 volt peak-to-peak
signal from 20 kHz to 1 MHz will
blank or unblank the CRT. A 5
volt peak-to-peak signal will pro
duce noticeable modulation. Posi
tive portion of the signal blanks
CRT beam.
Remote Control Connector
Remote Erase -
Upper Screen
Lower Screen
Remote Erase and
Reset
Ground pin A.
Ground pin B.
Ground pin E.
Remote Single Sweep
Reset Ground pin F.
Remote Save Ground pin C.
Remote Store -
Upper Screen Ground pin H.
Lower Screen Ground pin J.
Aand B SWEEP GENERATOR
TRIGGERING FEATURES
Source Internal (from trigger pickoff cir
cuit in the vertical amplifier or from
the plug-in unit), external and line.
Coupling Direct (DC), capacitive (AC) or low-
frequency rejection (AC LF REJ).
Slope Trigger on positive going or nega
tive going portion of trigger signal.
Mode Automatic or Trig, adjustable stabil
ity at an adjustable level and free
running sweep.
Triggering Performance1
A Time Base
Source Coupling Condition
NORM
(internal) DC Minimum 0.2 cm of deflection, DC
to 10 MHz, increasing to 2.0 cm at
30 MHz.
AC Same amplitude as DC. 300 Hz to
30 MHz,
AC LF REJ Same amplitude as DC. 200 kHz to
30 MHz.
PLUG-IN
(internal) Triggering dependent on plug-in
unit performance.
EXT DC Minimum 0.3 volt signal, DC to 10
MHz increasing to 3 volts at 30
MHz.
AC Same amplitude as DC, 300 Hz to
30 MHz.
AC LF REJ Same amplitude as DC, 200 kHz to
30 MHz.
1 Upper and lower frequenc triggering requirements for Time Base
A are shown in Fig. 1-2.
1-2

Characteristics— Type 549
B Time Base2
Source Coupling Condition
NORM
(internal) DC Minimum 0.2 cm of deflection, DC
to 1 MHz, increasing to 1 cm at 10
MHz.
AC Same amplitude as DC, 300 Hz to
10 MHz.
AC LF REJ Same amplitude as DC, 200 kHz to
10 MHz.
PLUG-IN
(internal) Triggering dependent on plug-in
unit performance.
EXT DC Minimum 0.3 volt signal, DC to 1
MHz, increasing to 1.5 V at 10 MHz.
AC Same amplitude as DC, 300 Hz to
10 MHz.
AC LF REJ Same as DC, 200 kHz to 10 MHz.
Automatic Mode: Time Base A and Time Base B3
Source Condition
NORM (internal) Minimum 0.2 cm of deflection, 50
Hz to 10 kHz, increasing to 2 cm at
1 MHz. '
EXT Minimum 0.3 volt signal, 50 Hz to
10 kHz, increasing to 3 V at 1 MHz.
External Trigger Input characteristics:
Time Base A 1 megohm paralleled with 25 pF
except the AC LF REJ coupling
which is approximately 91 kilohms.
3 Upper and lower frequenc triggering requirements are shown in
Fig. 1 -3.
3 The Automatic Mode triggering features shown in Fig. 1 -2 and
1-3 are applicable onl when using AC coupling.
Time Base B 1 megohm paralleled with 0 pF,
except the AC LF REJ coupling
which is approximately 91 kilohms.
Maximum Exter- 50 volts, combined DC and AC
nal Input Voltage peak.
POWER SUPPLY REQUIREMENTS
AND FEATURES
Trans Pri Sel A switch selects the center voltage
of two operating ranges: 9 to 138
VAC or 187 to 279 VAC.
LINE RANGE Selector LOW: 10 VAC ± 1 0 % or 208
VAC ± 1 0% .
MED: 115 VAC ± 1 0 % or 230
VAC ± 10 % .
HIGH: 127 VAC ± 1 0 % or 25
VAC ± 1 0% .
Line Voltage Frequency 50 to 60 Hz.
Input Power (Maximum) 750 volt amperes, 650 watts.
Thermal Protection Automatic resetting thermal cutout
which interrupts instrument power
if internal temperature exceeds a
safe operating level.
MECHANICAL FEATURES
Construction Aluminum alloy chassis. Anodized
front panel. Blue vinyl coated cabi
net.
Overall Dimensions 13 inches wide, 2 inches long and
17 inches high.
Standard accessories supplied with the instrument will be
found on the last pull-out page at the back of the manual.
For optional accessories see Tektronix, Inc. catalog.
®I 1-3

Fig. 1-2.
TYPE 549 TIM E-BASE A
TRIG GERIN G SIG N AL REQUIREMENTS
I
2*
Frequenc
j§
Characteristics— Type 549

CM, Peak-to-Peak NORM (Internal)
TYPE 5 49 TIM E-BASE B
TRIG GERIN G SIG NA L REQUIREM ENTS
1 10 100 l k 10 k 100 k 1 M 10 M
Frequenc
■a
n
Ur
VOLTS, Peak-to-Peak EXT

SECTION 2
OPERATING INSTRUCTIONS
Introduction
The Type 5 9 combines high speed storage with a general
purpose laboratory oscilloscope. This section of the manual
describes operation and applications of the instrument.
The description begins with the storage tube and its oper
ational characteristics, then covers each front and rear panel
control, switch and connector.
Circuit functions and modes of operation for the Type 5 9
are described next, with emphasis on storage and storage
technique. -
The section concludes with general oscilloscope measure
ment applications.
Storage Tu es
Terms and storage nomenclature used in this manual are
defined at the start of the circuit description section. A
brief discussion on storage tube principles is also presented.
The storage tube in the Type 5 9 is a relatively new tube,
and can be more easily damaged than conventional CRT's.
However with reasonable care they will provide very satis
factory servise. The following precautions will prevent dam
age, increase tube life and maintain optimum performance.
Protective circuitry is incorporated to limit beam inten
sity. However, a repetitive sweep over the same area for
extended periods may damage the storage target. Use only
the intensity level required to write a well-defined display.
Turn the INTEN SITY control to its minimum setting during
warm-up time and before changing to slower sweep speeds
or switching the HORIZONTAL DISPLAY selector.
Turn the IN TEN SITY control counterclockwise and the
POWER switch to OFF when changing plug-in units.
Avoid continued use of one target area. This causes dif
ferential aging of the storage target and may result in dif
ferential light emitting qualities over the target area.
Avoid leaving stored display on the screen longer than
required. Operation in the ready-to-write (fully erased)
state will give longer target life.
When store operation is no longer required, shift to con
ventional mode operation. Conventional operation does not
deteriorate the storage screens; however, avoid prolonged
display periods of a repetitive waveform or a free running
sweep. These may cause a residual image of the display to
appear in the store mode.
Readjustment of the focus and astigmatism is usually
required after the beam intensity level is changed to main
tain optimum writing speed.
Storage tube characteristics change with use more notice
ably than characteristics of conventional tubes. Circuit cali
bration should, therefore, be checked frequently to ensure
optimum operation. Operating levels for a new tube should
be checked after the first 100 hours of operation. Progres
sively longer periods between checks may then be set.
Storage Target Phenomena
The storage screen may display unusual dark or bright
areas which resemble previously written information. Three
different types of residual images may be noted.
1. Negative residual image.
This appears in the ready-to-write state as a negative
image of some previously stored display. It is caused by
leaving a stored display on the target over an extended
period. This type of image usually disappears within a few
hours of operation.
2. Bright residual image.
This appears only in the enhanced mode as a bright image
of some previously written display. The secondary emission
characteristics of the affected target area have changed so
that they fade positive when pulsed by the enhanced pulse
while the reminder of the target area reacts normally.
These bright residual images are caused by stored dis
plays for extended periods. They are not a problem if the
enhance level is kept below the point the images appear and
with time will fade away.
3. Dark Burn.
This is a spot or line across the screen which has a lower
light level than the rest of the target when the target is
fully written. If extreme, the dark burn area will not store.
Dark burn is caused by the destruction of the storage
screen from a high intensity writing beam and is similar to
phosphor burn in a conventional CRT.
This type of damage may remain indefinitely if the burn
is extensive.
Generally, non-destructive type images will fade in about
the same period of time it took to produce them. It is import
ant to age the target area as uniformly as possible to main
tain uniformity in writing speed and light level.
General Information
The Type 5 9 will operate in ambient temperatures up to
122° F (50° C). A minimum of two inches unobstructed clear
ance around the instrument is recommended for adequate
ventilation. If the internal temperature becomes too high,
a thermal cutout will open and disconnect power until the
internal temperature has returned to approximately 115° F.
If this occurs, check to see that air circulation and ventila
tion are adequate. Constant temperature is important for
accurate operation of the instrument.
The instument requires a minimum 20 minute warm-up
period at ambient room temperature of +25° C ± 5 ° C for
rated accuracies.
@2 2-1

Operating instructions— Type 549
Line Voltage Selection
115 or 230 volt line voltage is selected by means of an
internal switch SW602. Three voltage ranges, LOW 10 /
208, MED 115/230 and HIGH 127/25 are selected by the
LINE RANGE switch SW602 on the back panel. The instru
ment is normally shipped with these switches set for 115 V.
Line frequency is 50 to 60 Hz.
CAUTION
Before applying power to the instrument, check
that the 115V /2 3 0 V internal selector switch
(located at the rear of the vertical amplifier
chassis) is positioned correctly for the power
source voltage.
FUNCTION OF CONTROLS
AND CONNECTORS
NOTE
The Time Base A and Time Base B controls serve
identical functions with the exception of the
LENGTH control.
TRIGGERING
LEVEL. Selects the amplitude point on the triggering signal
where sweep triggering occurs.
STABILITY. Adjust the sweep triggering circuits for a
stable display. The STABILITY control can generally be set
to the PRESET position and left there. This PRESET position
with the LEVEL control midrange, provides stable triggering
for most displays.
MODE. AUTO position permits normal triggering on
signals with repetition rates higher than about 50 Hz. With
no trigger signal, or with a lower repetition rate, the time
base circuit free runs to provide a reference trace. TRIG
(triggered) position permits normal triggering on all trigger
ing signals. No trace occurs when the triggering signal is
removed.
SLOPE. Determines whether the time base is triggered on
the negative (—) or positive (+) going slope of the signal.
COUPLING. AC position blocks the DC component of the
triggering signal and allows triggering to occur only on the
changing portion of the signal. With frequencies below
about 30 Hz, use the DC position. AC LF REJ position attenu
ates trigger signal frequencies below about 17 kHz, allowing
the trigger circuits to respond only to higher frequencies.
DC position permits triggering on both high and low (to DC)
frequency signals.
SOURCE. INT NORM position uses a portion of the signal
applied to the vertical deflection plates of the CRT as a
trigger signal. INT PLUG IN position applies to multitrace
plug-in units that provide a single-channel trigger signal
through pin 5 of the interconnecting plug (e.g. Tektronix
Type 1A1 plug-in unit). LINE position uses a line-frequency
signal as a trigger. EXT position permits external triggering
on a signal applied to the TRIGGER INPUT connector.
Time Base Controls
TIME/CM. Selects the time-base sweep rate.
VARIABLE (Time Base A). Provides an uncalibrated sweep
rate adjustment which will slow the sweep rate to at least
2.5 times the setting of the TIME/CM switch. An UNCALI
BRATED lamp lights when the VARIABLE control is not in the
CAL position.
LENGTH (Time Base B). Controls the length of the B sweep.
HORIZONTAL DISPLAY. A.- Selects only Time Base A for
display on the CRT screen. B: Selects only Time Base B for
display on the CRT. B INTEN BY A: One of the delayed-
sweep functions. In this position a portion of Time Base B
is intensified during the time that Time Base A (the delayed
sweep) is in operation. A DLY'D: Another delayed-sweep
function. In this position, Time Base A is delayed at the
end of each delay period as determined by the B, TIME/CM
AND DELAY TIME switch setting and the DELAY-TIME M ULTI
PLIER 1:10 dial reading. EXT I X and 10X : Permits an
external signal to be applied to the horizontal deflection
circuit. Sensitivity is continuously variable with the VARIABLE
1-10 control.
READY Lamp. Lights when time-base circuit is ready for
triggering after being reset.
MAGNIFIER. Horizontally expands the portion of the sweep
in the center of the graticule by 5 times at any setting of
the TIME/CM switch.
NORM-SINGLE SWEEP (Sweep mode selector). Three-
position switch selects NORMAL or SINGLE SWEEP operation
for either time base. Switch is spring loaded at the RESET
position. In the SINGLE SWEEP position, selected time base
will sweep once upon receipt of trigger signal, then remain
inactive until the circuit has been reset with the RESET switch
or ERASE AND RESET button. Single sweep permits photo
graphing or storage of nonrepetitive waveforms.
DELAY-TIME MULTIPLIER 1-10. Works in conjunction with
the Time Base B TIME/CM AND DELAY TIME switch. Varies
sweep delay from 0 to 10 times the rate indicated by the
Time Base B TIME/CM AND DELAY TIM E switch.
HORIZONTAL POSITION and FINE. Positions the display
along the horizontal axis of the crt screen.
LOCATE button. When the Type 5 9 is operating as a
conventional oscilloscope, the LOCATE button provides a
trace finding mode. The gain of both the vertical and hori
zontal amplifiers is reduced so that regardless of the input
signal, an on-screen display is presented. With either of the
STORE buttons depressed the LOCATE button does not
affect the horizontal or vertical gain, but the Horizontal
Amplifier is DC offset and moves the beam to the left of the
CRT screen. This places the beam in the locate zone of the
target (a non-store area) and permits vertical positioning
of the beam.
In either mode, the intensity is brought to a preset level
when the LOCATE button is depressed.
Other Controls
AMPLITUDE CALIBRATOR. Determines the peak-to-peak
voltage available at the CAL OUT connector.
5 mA Current Strap. Provides a calibrated source of
square-wave current. The arrow indicates conventional cur
rent (i.e. positive to negative).
2-2 ®T

Operating Instructions— Type 549
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Fig, J-T . Front panel tontroli end conneclors.

Operating Instructions— Type 549
F ig . 2-1. R e a r penal co ntrols and connectors. IAJ Upper portion o f b ack panel. (B) Lo w er portion o f b ac k panel.
POWER. Toggle switch for applying or removing power
to the instrument.
INTENSITY, Controls writing gun beam current.
FOCUS. Used in conjunction with the INTEN SITY and
ASTIGMATISM controls for obtaining a well-defined display.
ASTIGMATISM. Used in conjunction with the IN TENSITY
and FOCUS controls to obtain o well-defined display.
TRACE ROTATION. Permits horizontal alignment of the
trace to the horizontal lines of the graticule.
SCALE ILLUM. Varies illumination of the grid lines of the
graticule.
EXT HORIZ IN. Connector to apply external Horizontal
signal when the HORIZONTAL DISPLAY switch is set to
either I x or 1 0 x EXT position.
TRIGGER INPUT [Time Base A and B]. Connector for
applying an externa! trigger signal to the time base when
the respective TRIGGERING SOURCE switch is set to the
EXT position.
DLY'D TRIG. Supplies a positive-going trigger output of
about 7 volts at the end of the delay period as set by the
TIME/CM AND DELAY TIM E switch and the DELAY TIME
MULTIPLIER 1:10 dial,
+G A TE B. Supplies on approximate 20 to 0-volt square-
wave output pulse when Time Base B is operating. Pulse
duration is same as the B sweep length.
+G A TE A. Same as + GATE B except that it applies ro
Time Base A.
SWEEP A. The sweep ramp voltage of Time Base A. Peak
amplitude is about +150 volts.
VERT SlG OUT. Vertical signal output connector. Output
amplitude is approximately 1.5 volts/cm of vertical deflec
tion.
CRT CATHODE SELECTOR. Provides blanking of the
between-channel switching transients (in the CHOPPED
BLANKING positions] when using multi channel plug-in units
in the chopped mode. The CRT CATHODE SELECTOR switch
should be in the NORM position except when using the
chopped mode.
CRT GRID SELECTOR. Provides selection between the EXT
CRT GRID connector in the EXT position or the unblanking
signal from the time base in the NORM position, for Z ozis
modulation to the CRT grid.
EXT CRT GRID. Connector allows Z-axis modulation of the
CRT grid (DC coupled) when the CRT GRID SELECTOR switch
is in the EXT position. Normal trace blanking is removed
with the switch in the EXT position-
EXT CRT CATHODE. Connector allows Z-axis modulation
of the CRT cathode (AC coupled). A grounding BNC cap
is provided for normal operation.
REMOTE CONTROL INPUT. Provides remote operation of
the single sweep reset functions, erasure of each target and
2-4

Operating Instructions— Type 549
remote store function. These functions can be controlled by
completing the circuit to ground. See the Characteristics
section,
A remote Storage Oscilloscope Control Unit (Tektronix
Part Number 012-0102-00) is available as an optional item.
This unit contains upper and lower erase buttons and a
sweep reset button. See Fig. 2-3.
Primary Voltage Range Switches. SW602 (Internal). A two
position switch selects line voltages from 93.6 to 138.6 VAC,
or 187.2 to 279.2 VAC depending on the position of the
LINE RANGE switch SW603.
Fig. 1-3. Remote control unit.
LINE RANGE,
nominal value: Three position switch selects center
LOW MED HIGH
10 VAC 115 VAC 127 VAC
208 VAC 230 VAC 25 VAC
CAUTION
Be sure that the interna! switch SW 602 is in the
230 VAC position when the power cord is con
nected to a 230 VAC nominal supply source.
Store Controls
UPPER and LOWER SCREEN STORAGE: OFF-STORE-
ERASE push buttons provide conventional or stored mode
operation, with manual ERASE control to erase stored infor
mation.
INTEGRATE: Permits storage of very fast repetitive signals,
by permitting the writing gun beam to accumulate charges
on the target while the flood gun beams are turned off.
Erase Program
SCREEN SELECTOR: Selects UPPER, FULL or LOWER screen
for the erase program.
VIEW ING TIME: Variable control that selects display time
between erasures when in the auto erase mode. Viewing
time varies from approximately 0,5 to 5 seconds.
ERASE and RESET Button: Erases display and resets sweep
circuit.
Auto Erase
PERIODIC: Erases the target automatically, independent
of sweep operation, at a time period determined by the
VIEW ING TIME control setting.
AFTER SWEEP: Erases the display after the sweep has
run. Viewing time is determined by the setting of the VIEW 
ING TIME control, Resets the sweep circuit after erasure,
OFF: With erase program switch in the OFF position,
display must be erased manually,
BASIC OSCILLOSCOPE OPERATION
Sweep Triggering
Proper sweep triggering is essential for a stable presenta
tion of an input signal. The sweep must be triggered at
the same time relative to the displayed signal. Thus, the
sweep must be triggered by the input signal or by some
external signal that has a fixed time relationship with the
displayed signal. The external trigger signal must be the
same frequency or a sub-multiple of the input signal.
Fig. 2-4. AMPLITUDE CA LIBRATO R, triggered waveform.
ENHANCE MODE: Permits storage of high speed wave
forms by momentarily changing CRT voltage operating
levels to increase writing speed. A four position ENHANCE
MODE switch permits UPPER Screen, FULL Screen or LOWER
Screen enhancement.
ENHANCE LEVEL control permits adjustment for optimum
enhancement.
The SOURCE switch selects one of a variety of possible
triggering signals. For most applications, the sweep can be
triggered internally from the displayed signal. This occurs
with the SOURCE switch set at NORM position.
The PLUG-IN position is used with plug-in units that
supply a single-channel triggering signal through pin 5 of
the interconnecting plug, such as the Tektronix Type 1A1
2-5

Operating Instructions— Type 549
TYPE 549 STORA E OSCILLOSCOPE F AS T ’ UPPER SCREEN S TO RA E
INTENSITY FOCUS ASTI
TRACE ROTATION
ERASE PRO RAM
SCREEN SELECTOR AUTO ERASE
VIEWIN G TIME
Fig. 2-5. Control setup chart.

Operating Instructions— Type 549
Fig. 2-6. Effects of the TRIG GER ING LEVEL and SLOPE controls.
2-7

Operating Instructions— Type 549
Dual Trace Plug-In Unit. This position is useful when oper
ating the plug-in unit in dual-trace chopped-mode operation,
since the triggering signal is the same as the applied signal
and is free from any between-channel switching transients.
External triggering is often used when signal tracing in
amplifiers, phase-shift networks, and wave shaping circuits.
The signal from a single point in the circuit can be used
as the external trigger signal. With this arrangement, it is
possible to observe the shaping and/or amplification of a
signal at various points through the circuit without resetting
the triggering controls for each new display.
In general, use AC coupling, unless it is necessary to use
DC coupling for very low-frequency signals. When line-
frequency hum is mixed with the triggering signal, use AC
LF REJ coupling so that triggering takes place only on the
desired signal (if the signal contains frequency components
higher than 17 kHz).
The AC LF REJ position is also useful when triggering
internally from multi-trace plug-in units operated in the alter
nate dual-trace mode (unless the plug-in unit is a Type 1A1
and the SOURCE switch is set to PLUG IN). AC LF REJ
coupling has a faster recovery time when subjected to the
alternate DC levels from the multi-trace plug-in unit.
Selecting Trigger Slope
The trigger SLOPE switch determines whether the trigger
ing circuit operates on the rising (+ setting) or the falling
(— setting) portion of the triggering signal. If a certain
portion of a waveform is to be examined, the SLOPE switch
will start the display on the desired slope of the input signal.
Fig. 2-6 illustrates the effect of both the SLOPE and TRIG
GERING LEVEL controls.
Selecting Trigger Mode
The automatic stability mode is more convenient in most
cases. With the MODE switch set to AUTO, proper trig
gering takes place if the signal is faster than 50 Hz. When
the triggering signal is removed, the time-base circuit auto
matically free runs and presents a reference display.
The TRIG position of the MODE switch should be used
if the trigger signal has a low repetition rate (below about
50 Hz).
Setting Sta ility Control
In most triggering applications, satisfactory operation can
be obtained with the STABILITY control in the PRESET (fully
counterclockwise) position. If triggering becomes difficult
with the STABILITY control at PRESET, it may be necessary
to adjust the STABILITY control. To adjust, set the LEVEL
and STABILITY control in the fully counterclockwise position,
then turn the STABILITY control slowly clockwise until a
trace appears on the CRT. The correct setting is obtained
by turning the control counterclockwise three to five degrees
from the point where the trace appears. The setting is just
below a free running sweep.
Setting Triggering Level
The TRIGGERING LEVEL control determines the amplitude
point on the signal where triggering occurs.
The trigger circuit is most sensitive to AC triggering signals
with the TRIGGERING LEVEL control set near zero. Moving
the TRIGGERING LEVEL control in the -|- direction causes
the trigger circuit to operate at some higher positive ampli
tude on the triggering signal. Moving the TRIGGERING
LEVEL control in the — direction causes the trigger circuit
to operate at some higher negative amplitude on the trig
gering signal. See Fig. 2-6.
Selecting TIME/CM (Sweep Rate)
The TIME/CM and the MAGNIFIER switches determine
sweep rate. The MAGNIFIER expands either time base
sweep rate by a factor of 5.
first ninth
Number of x TIM E/CM Switch
Time Duration = Centimeters ______________ Setting _____
SWEEP M AGN IFIER Setting
Fig. 2-7. Area of graticule used for accurate time measurements.
With the VARIABLE control in the CAL position the TIME/
CM switch provides a wide selection of calibrated sweep
rates. When making time measurements from the CRT
graticule, be certain the VARIABLE (Time Base A) control is
in the CAL position.
The VARIABLE control provides a continuously variable
uncalibrated sweep rate. The UNCAL neon lights when the
VARIABLE control is at other than the calibrated (detent)
position.
When the MAGNIFIER switch is set to the OFF position
the TIME/CM switch indicates sweep rate. With the MAG
NIFIER switch set to the X 5 position the setting of the
TIME/CM switch must be divided by 5 to determine sweep
rate. (i.e. If the TIME/CM switch is set to 1 mSEC the sweep
rate would be 0.2mSEC/CM.) When making time measure
ments from the graticule, the horizontal portion between the
1st and 9th centimeter lines is the most linear. See Fig. 2-7.
Single Sweep Operation
For applications where the displayed signal is not repeti
tive or varies in amplitude, shape or time, a photograph or
storage of the display may be best achieved with the single
sweep feature of this instrument.
2-8 ®i

Operating Instructions— Type 549
(A )
(B )
Fig. 2-8. Operation of sweep m agnifier. (A ) W aveform with
M AGN IFIER in OFF position. (B) M agnified waveform. M AG N I
FIER in X 5 position.
To operate the single sweep feature, first make certain
the trigger circuit will trigger on the event to be displayed.
With the HORIZONTAL DISPLAY switch set to the desired
time base and the MODE switch set to TRIG position, adjust
and set the TRIGGERING controls and switches for a trig
gered display.
Set the NORM-SINGLE SWEEP-RESET switch to the SINGLE
SWEEP position.
Push the switch to the spring loaded RESET position and
release, or push the ERASE and RESET button in the ERASE
PROGRAM sector.
The ERASE AND RESET button should light and stay lit,
indicating the trigger circuit is armed and ready for a trigger
signal. When the circuit is triggered the sweep will run and
the ERASE AND RESET ready-light will go out, indicating
the circuit has been triggered.
To ready the circuit for another event, push the ERASE
AND RESET button or the SINGLE SWEEP switch to the
RESET position and release.
Delayed Sweep Operation
The start of the horizontal sweep can be delayed for a
period of 1 µs to 10 s after the triggering signal is applied.
This is accomplished in the Type 5 9 by the simultaneous
use of both time bases. Control of the sweep delay is
governed by the settings of the Time Base B TIME/CM AND
DELAY TIME switch and the DELAY TIME MULTIPLIER 1-10
control. See Fig. 2-9.
Fig. 2-9. Dela ed sweep operation.
The delayed sweep feature is operable when the HORI
ZONTAL DISPLAY switch is in the A DLY'D position. The
delay period is indicated by the settings of the B TIME/CM
AND DELAY TIME switch multiplied by the setting of the
DELAY TIME MULTIPLIER 1-10 vernier dial reading. For
example: TIME/CM AND DELAY TIME switch is set to 10
µSEC position and the vernier of the DELAY TIME M ULTI
PLIER 1-10 dial indicates 6.75. The delay time equals 6.75
X 10/µSEC or 67.5 microseconds. See Fig. 2-10.
With the HORIZONTAL DISPLAY switch in the B INTEN
BY A position and all controls set for delayed sweep opera
tion, a portion of the Time Base B sweep will be intensified
by the Time Base A sweep. The length of the intensified
portion is determined by the A TIME/CM switch setting.
The position of the intensified portion is dependent on the
DELAY TIME MULTIPLIER 1-10 control setting.
®1 2-9

Operating Instructions— Type 549
Fig. 2-10. Delay Time — B TIM E/C M AND DELAY TIM E setting
(10 µSEC) m ultiplied b DELAY TIME M ULTIPLIER 1-10 d ia l reading
((6.75) or 67.5 µSEC dela .
To expond a portion of Hie Time Base 8 sweep presenra-
lion, adjust the DELAY TIM E MULTIPLIER 1 - O and the A
Time Base TIME/CM controls lo include the portion of the
waveform to be expanded in the intensified portion, then
set the HORIZONTAL DISPLAY switch to the A DLY'D
position. This expands the intensified portion to the full
10 cm graticule width. The amount of magnification is the
ratio of Time Base 8 TIME/CM AND DELAY TIME setting
to the Time Base A TIME/CM control setting. For example;
Time Base B TIME/CM AND DELAY TIM E switch is set to
1 mSEC position ond Time Bose A TIME/CM switch is set
at 1 µSEC and the brightened portion is magnified hori
zontally 1,000 times, Practical sweep magnifications up to
approximately 10* are attainable.
When using the delayed sweep feature to obtain high
magnification, the trace may become very dim because of
the low duty cycle. The intensity can often be increased
throuqh the use of the Time Base B LENGTH control. Set the
HO RIZONTAL DISPLAY switch to the B INTEN BY A posi
tion and adjust the LENGTH control until the sweep stops
at a point just past the brightened portion of the trace.
Then, return the HORIZONTAL DISPLAY switch to the A
DLY'D position. Using this procedure, the maximum delayed
sweep repetition rate w ill be obtained.
External Horizontal Deflection
In some applications, it may be desirable to display one
signal versus another |X-Y) rather than against time (internal
sweep). The EXT HORIZ position of the HORIZONTAL
DISPLAY switch provides a means lo apply an external
signal to the horizontal amplifier and establish this type of
display.
To use the External Horizontal Amplifier, connect the
external waveform lo the EXT HORIZ INPUT connector and
place the HORIZONTAL DISPLAY switch in the 10X or 1 X
EXT HORIZ position. The horizontal deflection factor is
continuously variable from approximately 0.15 to approxi
mately 15 volts per centimeter with the VARIABLE 1-10
control and the 10X or 1 X position of the HORIZONTAL
DISPLAY switch. Remember when using this mode the hori
zontal deflection factor is uncalibrated.
Intensity Modulation
Intensity (Z axis) modulation can bo used to relate further
information to the displayed waveform, without changing
the X-Y information. The intensity modulation can be applied
to the rear panel EXT CRT GRID or the EXT CRT CATHODE
connectors. If the modulation signal is applied to the EXT
CRT GRID connector, place the CRT GRID SELECTOR switch
fa EXT position. In this position there is no blanking pulse
applied, therefore retrace is visible, The modulating signal
is DC coupled to the CRT grid.
If the modulation signal is applied to the EXT CRT CATH
ODE connector, the signal is AC coupled to the CRT cathode
when the CRT CATHODE switch is in the NORMAL position.
Only high frequency signals ore applicable (above 20 kHz).
At normal intensity levels an approximate 20 volt signal
will produce visible modulation.
Time markers applied to the connectors provide a direct
time reference on Ihe display. When using uncalibrated
horizontal sweep or external horizontal deflection, the time-
markers provide direct time display information to the
waveform. If the markers are not time-related to the display,
single sweep display should be used.
When Z axis modulation is not in use, keep the CRT GRID
SELECTOR switch in the NORMAL position and the ground
ing cap installed on the EXT CRT CATHODE.
Amplitude Cali rator
The Calibrator provides a convenient source of square
waves of known amplitude at a frequency of approximately
1 kHz. The voltage output from the Calibrator is adjustable
through 18 steps from ,2mVOLTS to 100 VOLTS peak to
peak. An additional step provides 100 volts DC. The source
impedance of the .2 mVOLT to 0.2 VOLT range is 50Ω
+/-2%,
2-10

Operating Instructions— Type 549
The current link provides 5 milliamp current signal, which
can be used to check and calibrate current probe systems.
This current signal is obtained by clipping the probe around
the current loop. Current is available and constant through
the loop when the AMPLITUDE CALIBRATOR switch is in
the 100 VDC position. The arrow indicates conventional
current (i.e. positive to negative).
Control and Circuit Functions
Control Setup Chart: Fig. 2-5 is a control setup chart of
front panel controls which may be reproduced and used as
a test setup record for special measurements, applications or
procedures. It may also serve as a training aid device for
familiarization with this instrument.
First Time Operation (Initial set-up)
Install a plug-in unit (such as Type 1A1 or 1A2) in the
vertical compartment of the Type 5 9.
Check the position of the primary voltage range switches
and switch to settings that correspond to available power
source.
Set the front panel controls of the Type 5 9 as follows:
HORIZONTAL DISPLAY A
MAGNIFIER OFF
NORM-SINGLE NORM
SWEEP-RESET
A TIME/CM 1 mSEC
VARIABLE CAL
TRIGGERING switches Place all switches in
up position
STABILITY PRESET
LEVEL Midrange
STORAGE Controls
ENHANCE MODE OFF
UPPER and LOWER
SCREEN STORAGE OFF
SCREEN SELECTOR FULL
VIEWING TIME Midrange
AUTO ERASE OFF
CRT Controls
INTENSITY Fully Counterclockwise
FOCUS Midrange
ASTIG Midrange
AMPLITUDE CALIBRATOR 1 VOLT
Vertical Unit
Volts/Div 0.5
Input Selector AC
Connect a coaxial cable between the CAL O UT connector
and the vertical Input connector.
Connect the Type 5 9 to a suitable power source and
turn the POWER switch to ON. Allow a few minutes for
the delay time relays to energize and the instrument to
stabilize.
Push the LOCATE button and position the display to the
center of the graticule area with the HORIZONTAL and
Vertical POSITION controls. Note the preset intensity level.
Release the LOCATE button and adjust the INTENSITY,
FOCUS and ASTIG controls for a well defined display of
nominal brightness. See Fig. 2- . The FOCUS control should
be adjusted for the best vertical definition and the ASTIG
control should be adjusted for equally focused horizontal
and vertical segments of the displayed waveform.
Remove the signal cable between the CAL O UT connector
and the vertical Input connector.
Trace Alignment
If the free running trace is not parallel with the horizontal
graticule lines, adjust TRACE ROTATION so the trace is
parallel with the horizontal graticule lines.
Locate Logic
When the Type 5 9 is operating in the conventional mode
the LOCATE pushbutton provides a trace locating mode.
The gain of both horizontal and vertical amplifiers is reduced
so that regardless of the input signal, an on-screen display
is presented.
With either of the STORE switches depressed the locate
button does not affect the horizontal or vertical gain but
the horizontal amplifier is DC offset and moves the beam
to the left of the CRT screen. This places the beam in the
locate zone of the target, which is a non-store area and
permits vertical positioning of the beam. In either mode
the intensity level is brought to a preset level when the
LOCATE button is pushed.
Storage Controls And Operating Technique
This section covers primary control operation for storage
and illustrates their function in storage technique. Fig. 2-11
illustrates the storage controls for the Type 5 9. The primary
control is the UPPER and LOWER SCREEN STORAGE push
buttons. The OFF and STORE buttons are self-cancelling,
so depressing one of the buttons returns the other to its
cancelled position. The ERASE button is spring loaded and
independent of the STORE and OFF button.
To the left of the pushbuttons are the FAST WRITING
controls. The INTEGRATE TRACES pushbutton provides inte
grate mode operation and allows the storage targets to
accumulate charges from a repetitive writing gun beam
which is too fast for single trace writing. Integration is ac
complished by opening the flood gun cathode lead to
allow the writing beam to sum charges over the target
area so that these areas shift into storage when the button
is released. See storage tube principles in the Circuit Descrip
tion section.
Integrate mode is most useful on very fast low repetition
rate signals.
The ENHANCE MODE and the ENHANCE LEVEL provide
extended capabilities for single event writing by target
pulsing. This mode is effective for sweep rates of approxi-
2-11