Tektronix 214 User manual

Tektronix
COMMITTED TO EXCELLENCE
WARNING
THE
FOLLOWING
SERVICING
INSTRUCTIONS
ARE
FOR USE
BY
QUALIFIED
PERSONNEL
ONLY.
TO
AVOID
PERSONAL
INJURY,
DO
NOT
PERFORM
ANY
SERVICING
OTHER
THAN
THAT
CONTAINED
IN OPERATING INSTRUCTIONS
UNLESS
YOU
ARE
QUALIFIED
TO
DO
SO.
Tektronix, Inc.
P.O. Box 500
Beaverton, Oregon 97077
070-1483-00
214
STORAGE
OSCILLOSCOPE
SERVICE
INSTRUCTION MANUAL
Serial Number
First Printing AUG 1973
Revised APR 1981

http://manoman.sghill.com
Q ©
“ip x < a t -
. ; o 1 i
. Printed in U.S.A. Specification and price change
privileges are reserved.

SECTION 1
SECTION 2
TABLE OF CONTENTS
INTRODUCTION
General Information
Specifications
Vertical Deflection System
Triggering
Horizontal Deflection System
Display
Isolation
AC Operation
Internal Battery Operation
Environmental
Physical
FUNCTIONS OF CONTROLS AND CONNECTORS
Front Panel Controls
Side Panel Controls
SECTION 3 MAINTENANCE
REV APR 1981
Introduction
Preventive Maintenance
General
Cleaning
Lubrication
Visual Inspection
CRT Care
Recalibration Information
Disassembly Instructions
Troubleshooting
Introduction
Troubleshooting Aids
Troubleshooting Equipment
Corrective Maintenance
Obtaining Replacement Parts
Component Replacement
Recalibration After Repair
Instrument Repackaging
Page
1-1
1-1
1-2
1-2
1-2
1-2
1-3
1-4
1-4
2-1
2-2
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-2
33
3-3
3-3
3-3
3-3
3-4
3-6
214 Service

214 Service
TABLE OF CONTENTS (cont)
SECTION 4 CALIBRATION
General
Test Equipment Required
Special Calibration Fixtures
Preliminary Procedure
Preliminary Control Settings
Power Supply and Display
Check Power Supply DC Levels
Adjust CRT Grid Bias
Adjust FOCUS
Adjust Trace Rotation
Adjust Storage Operating Level
Adjust Wall Band Level
Adjust Enhance Level
Adjust Hum Balance
Vertical System
Adjust Vertical DC Centering
Adjust Channel 1 Step Attenuator Balance
Adjust Channel 2 Step Attenuator Balance
Adjust Vertical Gain
Adjust Storage Vertical Gain
Check Channel 2 Variable Volts/Division Range
Check Channel 2 Volts/Division Accuracy
Check Input Coupling Switches
Check CH 1 Volts/Division Accuracy and
Variable Volts/Division Range
Check Channel 1 Volts/Div Compensation
Check Channel 2 Volts/Div Compensation
Check Vertical Amplifier Bandwidth
Trigger Circuit
Adjust AUTO PRESET Level
Check Trigger Circuit Operation
Check Single Sweep Operation
Horizontal System
Adjust Horizontal Centering
Adjust Horizontal Gain
Adjust Sweep Calibration
Check Variable Horizontal Magnifier Range
Check SEC/DIV Accuracy
REV. APR 1974
Page
4-1
4-1
4-1
4-3
4-3
4-4
4-4
45
45
45
4-5
4-6
4-7
47
4-8
4-8
4-8
4-8
4-9
4-9
4-9
4-9
4-10
4-10
4-10
4-11
4-12
4-13
4-13
4-13
4-13
4-15
4-15
4-15
4-15
4-16
4-16
@1

REV. C, OCT. 1975
TABLE OF CONTENTS (cont)
SECTIONS TROUBLESHOOTING AIDS
Diagram Information
Component Color Coding
Troubleshooting Equipment
SECTION6 CIRCUIT DESCRIPTION
Block Diagram Description
Circuit Operation
Vertical Input Amplifiers
Vertical and Horizontal Output Amplifiers
Trigger Generator
Sweep Generator
Single Sweep
Storage
Power Supply
CRT Circuit
SECTION 7 DELETED
(INFORMATION NOW INCORPORATED IN SECTION 3)
SECTION 8 ELECTRICAL PARTS LIST
OPTION INFORMATION
SECTION9 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
SECTION 10 MECHANICAL PARTS LIST
CHANGE INFORMATION
Page
5-1
5-1
5-1
6-1
6-1
6-3
6-3
6-3
6-3
6-3
6-4
6-7
6-9
214 Service

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Tektronix 214 Storage Oscilloscope.
214 Service

Section 1—214 Service
INTRODUCTION
GENERAL INFORMATION
The Tektronix 214 Storage Oscilloscope is a solid-state
portable instrument that combines small size and light
weight with the ability to make precision waveform
measurements. It is designed for general-purpose applica-
tions where display storage is desired, along with conven-
tional (NONSTORE) operation. The instrument is
mechanically constructed to withstand the shock, vibration,
and other extremes associated with portability.
The dual-channel DC-to-500 kilohertz vertical system
provides vertical deflection factors from one millivolt (at a
reduced bandwidth) to 50 volts/division at the tip of either
of the integral high-impedance probes. The 214 will either
automatically chop or alternate, depending upon the sweep
rate. Single-trace operation is achieved by turning off either
channel with its position control. Single Sweep operation is
provided to display infrequently recurring events. The
trigger circuit provides stable triggering over the full range
of vertical frequency response.
The horizontal deflection system provides calibrated
sweep rates from 500 milliseconds to five microseconds/
division. Uncalibrated sweep rates, via a variable sweep
magnifier, are available to at least five times the indicated
sweep rate for a maximum of at least one microsecond/
division. Stored Automatic Enhance occurs (in the Single
Sweep mode) at sweep rates of 0.1 millisecond/division and
faster.
X-Y operation is provided with Channel 1 supplying the
horizontal deflection of the applied (X) signal, with a range
from less than one millivolt to 50 volts/division (at a
reduced bandwidth of 50 kilohertz). Channel 2 supplies the
vertical deflection of the applied (Y) signal.
The cathode-ray tube (CRT) is a direct-view bistable
Storage tube having a 6 X 10 division graticule (each
division equals 0.203 inch).
The 214 is operated either from AC line voltage or from
internal rechargeable batteries. The internal batteries are
recharged from the AC power line by the integral battery
charger (with the instrument OFF).
®
This instrument will meet the following electrical charac-
teristics after complete instrument calibration. These char-
acteristics apply over an ambient temperature range of
—15°C to +55°C (+5°F to +131°F) when operating from
the internal batteries, and 0°C to +40°C (+32°F to +104°F)
when operating from an AC line source, except as otherwise
indicated. Warmup time for given accuracies is five minutes.
SPECIFICATIONS
Vertical Deflection System
DEFLECTION FACTOR:
Calibrated Range: One millivolt to 50 volts/division. 15
steps in a 1-2-5 sequence.
Accuracy: Within 5% with VAR VOLTS/DIV control in
CAL position and gain correctly set at five millivolts/
division.
Uncalibrated (variable) Range: Continuously variable
between calibrated settings. Extends maximum deflection
factor to at least 125 volts/division.
BANDWIDTH (using six-division reference):
10 mV/DIV to 50 V/DIV: DC to at least 500 kilohertz.
5 mV/DIV: DC to at least 400 kilohertz.
2 mV/DIV: DC to at least 200 kilohertz.
1 mV/DIV: DC to at least 100 kilohertz.
Lower Bandwidth Limit, AC (capacitively) Coupled:
About two hertz at all deflection factors.
INPUT RESISTANCE: One megohm, within 5%.
INPUT CAPACITANCE:
1 mV/DIV to 50 mV/DIV: Approximately 160 pico-
farads.
100 mV/DIV to 50 V/DIV: Approximately 140 pico-
farads.
1-1

Introduction—214 Service
MAXIMUM USABLE INPUT VOLTAGE:
50 V/DIV to 0.1 V/DIV: 600 volts (DC + peak AC). 600
volts peak-to-peak AC (five megahertz or less).
50 mV/DIV to 1 mV/DIV: 600 volts (DC + peak AC).
AC not over two kilohertz or risetime not less than 100
nanoseconds.
CHOPPED MODE: From 500 ms/DIV to 2 ms/DIV of time
rate at approximately 40 kilohertz.
ALTERNATE MODE: From 1 ms/DIV to 5 us/DIV of time
rate,
INPUT IMPEDANCE MATCHING: Matched to within
10%.
GAIN ACCURACY BETWEEN CHANNELS: Within 5%
with both VAR VOLTS/DIV controls in CAL position and
gain correctly set at 5 mV/DIV.
Triggering
TRIGGER SENSITIVITY:
Internal:
COMP: 0.2 division from DC to 500 kilohertz.
CH 2: 0.2 division from 2 hertz to 500 kilohertz.
External: At least one volt from DC to 500 kilohertz.
PRESET TRIGGER LEVEL: Triggered at preset level on
positive slope of triggering signal. Sensitivity same as stated
above.
DISPLAY JITTER: 0.5 microsecond or less at 500 kilo-
hertz.
EXTERNAL TRIGGER:
Input Resistance: Approximately one megohm.
Input Capacitance: Approximately 30 picofarads.
Maximum Usable Input Voltage: Eight volts (DC + peak
AC). 16 volts peak-to-peak AC (one megahertz or less).
1-2
Horizontal Deflection System
SWEEP RATE:
Calibrated Range: 500 milliseconds to five micro-
seconds/division. 16 steps in 1-2-5 sequence.
Accuracy (over center eight divisions): Within 5% with
VAR HORIZ MAG control in CAL position and timing
correctly set at 1 ms/DIV (disregard first 0.5 microsecond
of sweep length).
Linearity (any two division portion within center eight
divisions): Within 5% (disregard first 10% of total sweep
length).
Variable Magnifier; Continuously variable between cali-
brated settings. Extends maximum sweep rate to at least
one microsecond/division.
CH 1 HORIZONTAL INPUT:
Calibrated Deflection Factor: One millivolt to 50 volts/
division.
Variable: At least five times magnification (using VAR
HORIZ MAG).
Accuracy: Within 10% (with VAR HORIZ MAG in
CAL).
X-Y Phasing: Less than 3° to five kilohertz.
Maximum Input Voltage: Same as for CH 1 (vertical).
Display
GRATICULE:
Type: Internal Black line, non-illuminated.
Area: Six divisions vertical by 10 divisions horizontal.
Each division equals 0.203 inch.
Stored Writing Speed
At least 80 divisions/millisecond. At least 500 divisions/
millisecond in Automatic Enhance (internal adjustment).
Isolation
INPUT COMMON TO 214 CASE EXTERIOR: (When
battery operated with AC power plug secured in the
insulated cover.) Maximum floating potential between
input common and 214 case exterior is not to exceed 500
volts RMS sinusoidal or 700 volts (DC + peak AC).
INPUT COMMON TO AC LINE: Maximum floating voltage
plus AC line voltage is not to exceed 250 Volts RMS
REV. B, AUG. 1974

sinusoidal, or 1.4 times the AC line voltage plus (DC + peak
AC) is not to exceed 350 volts
CAUTION
Due to the capacitive line input circuit, sudden volt-
age changes may cause damaging input current
transients. Avoid operating this instrument from
square-wave inverter supplies, or other sources that
produce large voltage transients.
AC Operation
LINE VOLTAGE RANGE:
Stored Mode: 110 to 126 volts AC. Batteries can not be
charged during AC operation. Instrument can be operated
between 104 and 110 volts with resulting slow discharge of
internal batteries.
Nonstore Mode: 104 to 126 volts AC. Instrument can be
operated without resulting discharge of internal batteries.
LINE FREQUENCY: 58 to 62 hertz.
NOTE
Refer
to
Option
and
Maintenance
information
for
other
Line
Voltages
and
Frequencies.
MAXIMUM POWER CONSUMPTION: Three watts or less
at 126 volts, 60 hertz.
Introduction—214 Service
Internal Battery Operation
BATTERIES: 10 rechargeable A size, nickel-cadmium cells.
CHARGE TIME (from AC line): 8 hours for full charge
(instrument off during charge cycle).
POWER (BATTERY) INDICATOR: When extinguished
indicates approximately five minutes of scope operating life
left in the batteries.
BATTERY EXCESSIVE DISCHARGE PROTECTION: In-
strument operation automatically interrupted when battery
charge drops to 10 volts, +0.5 volt.
TYPICAL OPERATING TIME (at maximum trace intensity
after full charge cycle at +20°C to +30°C):
NONSTORE Mode: 3.5 to five hours. Longest operating
time provided at lower trace intensity.
STORE Mode: 2.5 to 3.5 hours. Longest operating time
provided at lower trace intensity.
TYPICAL CHARGE CAPACITY (in reference to charge/
discharge at +20°C to +30°C or +68°F to +86°F) See
Table 1-1.
TABLE 1-1
Operating Temperature
+20°C to +30°C
Charge Temperature —15°C (+5°F) (+68°F to +86°F) +55°C (+131°F)
O°C (+32°F) 40% 60% 50%
+20°C to +30°C (+68°F to +86°F) 65% 100% 85%
+40°C (+104°F) 40% 65% 55%
REV.C, APR. 1976
1-3

Introduction—214 Service
Environmental
Temperature:
Operating from Batteries, —15°C to +55°C (+5°F to
+131°F)
Operating from AC Line, 0°C to +40°C (+32°F to
+104°F)
Non-Operating, —40°C to +60°C (—40°F to +140°F)
Altitude:
Operating, to 25,000 feet (maximum operating tem-
perature decreased by 1°C per 1,000 feet above 15,000
feet).
Non-Operating, to 50,000 feet.
Humidity (operating and non-operating): five cycles
(120 hours) to 95% relative humidity in reference to
MIL-E-16400F.
Shock (operating and non-operating): Tested with two
shocks at 150g, one-half sine, two millisecond duration
each direction along major axes.
Physical
WEIGHT (without accessories): 3.5 pounds (1.6 kilograms)
DIMENSIONS (measured at maximum points):
Height; 3.0 inches (7.6 centimeters)
Width: 5.25 inches (13.2 centimeters)
Depth: 9.5 inches (24.1 centimeters)

Section 2—214 Service
FUNCTIONS OF CONTROLS
AND CONNECTORS
Controls
and
connectors
necessary
for
operation
of
the
214
are
located
on
the
front panel
and
on
the
right
side
panel
of
the
instrument.
A
brief
description
of
each
control
and
connector
is
given
here,
Front Panel Controls
READY
Light—indicates
sweep
has
been
reset
and
a
single
display
will
be
presented
upon
receipt
of
an
adequate
trigger
signal.
SINGLE
SWP—when
pressed,
the
sweep
operates
in
the
Single
Sweep
mode.
After
a
sweep
is
displayed,
further
sweeps
cannot
be
presented
until
the
RESET
button
is
pressed,
RESET—when pressed and in the Single Sweep mode, a
single display will be presented after correct triggering.
After the sweep is completed, the RESET button must be
pressed again before another sweep can be displayed.
REV. B, AUG. 1974
a
214 sTORAGE
OSCILLOSCOPE
NOTE
After sustained use (30 min or more) of the instru-
ment in the Store mode with nothing written, the
writing speed may be reduced. !t may be improved
by leaving the CRT target fully stored for five to ten
minutes. This procedure may be repeated to refresh
the target in applications requiring maximum stored
writing rate.
STORE—when pressed, the CRT operates in the Storage
mode. With the button out, the CRT operates in the
conventional, NONSTORE, mode.
ERASE—momentary contact switch, that when pushed
and released erases a Stored display from the CRT.
VOLTS/DIV-—selects the vertical deflection factor in a
1-2-5 sequence (vertical VARiable must be in the CAL
position for indicated deflection).
POWER (BATTERY)-—red light to indicate when the
instrument is on. When light extinguishes, battery charge is
low and about five minutes of operating life remains.
2-1

Functions of Controls and Connectors—214 Service
CH2
TEKTRONIX®
Side Panel Controls and Connectors
INPUT COUPLING-—selects method used to couple the
channel input signal to the vertical amplifier system.
AC—DC component of input signal is blocked. Low
frequency limit (—3 dB point) is about 2 hertz.
GND-vertical amplifier input circuit is grounded.
The applied signal is connected to ground through a
large valve resistor to provide a precharge path for the
AC input coupling capacitor.
DC—all components of the input signal are passed to
the vertical amplifier system.
STEP ATTEN BAL-—screwdriver adjustment to balance
the vertical system for minimum trace shift when changing
deflection factors.
Vertical POS—controls the vertical position of the
appropriate trace. Detent turns the channel OFF.
VAR VOLTS/DIV—provides a continuously variable
deflection factor between the calibrated settings of the
VOLTS/DIV switch.
VERT GAIN-—screwdriver adjustment to set the gain of
the entire vertical system.
AUTO PRESET-screwdriver adjustment to set the
PRESET trigger point for AUTO sweep operation.
TRIG SOURCE-selects the source of the trigger signal.
COMP-—sweep is triggered from a DC-coupled sample
of the vertical signal after the vertical switching.
CH 2—sweep is triggered from an AC-coupled sample
of the CH 2 vertical signal before the vertical switching.
EXT—sweep is triggered from the DC-coupled signal
applied to the EXT TRIG banana jack.
LEVEL/SLOPE-selects the amplitude point and slope
of the trigger signal on which the sweep is triggered. When
the indicator dot is to the left or center, the sweep is
triggered on the positive-going slope of the trigger signal; to
the right of center, on the negative-going slope. When the
LEVEL/SLOPE control is set to the AUTO PRESET
detent, the sweep is automatically triggered at a preset level
on the positive-going slope.
INTENSITY—controls brightness of the CRT display.
SWP CAL-—screwdriver adjustment to provide calibrated
sweep timing.
POWER-—controls power to the instrument. Does not
interrupt charging current to the internal batteries when the
instrument is connected to an AC line voltage.
FOCUS-—screwdriver adjustment to obtain a well-defined
display.
VAR HORIZ MAG-—provides continuously variable
sweep magnification to a maximum of at least five times
the sweep rate indicated by the SEC/DIV switch.
HORIZ GAIN-—screwdriver adjustment to set the basic
gain of the horizontal system.
Horizontal POS—controls the horizontal position of the
trace.
SEC/DIV-—selects the sweep rate (VAR HORIZ MAG
must be in CAL detent for indicated sweep rate).
EXT TRIG—banana jack to establish common ground
between the 214 and the external signal source or equip-
ment under test.

Section 3—214 Service
SECTION 3
MAINTENANCE
Introduction
This section of the manual contains maintenance
information for use in preventive maintenance, corrective
maintenance, or troubleshooting of the 214.
PREVENTIVE MAINTENANCE
General
Preventive maintenance consists of cleaning, visual
inspection, lubrication, etc. When performed on a
regular basis, preventive maintenance can prevent instru-
ment breakdown and may improve the reliability of this
instrument. The severity of environment to which the
214 is subjected will determine the frequency of main-
tenance. A convenient time to perform preventive
maintenance is preceding recalibration of the instrument.
SIV IN IOI OI OOO
CAUTION $
S$ PRLLLPLLPL LO
Avoid the use of chemical cleaning agents which
might damage the plastics used in this instrument.
Avoid chemicals which contain hydrochloric acid,
sodium hydroxide, or sulfuric acid.
Cleaning
The 214 should be cleaned as often as operating
conditions require. Accumulation of dirt in the instrument
can cause component breakdown.
The high-impact plastic covers provide protection against
dust in the interior of the instrument. Loose dust accumu-
lated on these covers can be removed with a soft cloth or
small brush. The brush is also useful for dislodging dirt on
and around the exterior controls. Dirt that remains can be
removed with a soft cloth dampened in a mild detergent
and water solution. Abrasive cleaners should not be used.
Cleaning the interior should only be occasionally neces-
sary. The best way to clean the interior is to blow off the
accumulated dust with dry, low-velocity air. A soft-bristle
brush or a cotton-tipped applicator is useful for cleaning in
narrow spaces or for cleaning more delicate components.
REV. C, NOV. 1977
Lubrication
Generally, there are no components in the 214 that
require lubrication. No lubrication should be used on
the contacts or rotary parts of the rotary switches. The
reliability of potentiometers that are not permanently
sealed can be maintained by lubrication with a lubricant
that does not affect electrical characteristics (e.g.,
Tektronix Part No. 006-2574-00). Do not over-lubricate.
Visual Inspection
The 214 should be inspected occasionally for such
defects as broken connections, improperly seated transis-
tors, damaged circuit boards, and heat damaged parts. The
corrective procedure for most visible defects is apparent;
however, particular care must be taken if heat-damaged
components are found. Overheating usually indicates other
trouble in the instrument; therefore, correcting the cause of
the overheating is important to prevent recurrence of the
damage.
CRT Care
To prolong the useful life of the Storage screen, the
following precautions should be observed when operating
this instrument:
1. Care must be taken in the degree of writing-beam
intensity that is used, particularly when using slow sweep
rates, X-Y displays, or the STORE mode. Too-high beam
intensity may permanently damage the CRT screen.
2. Avoid repeated use of the same area of the screen. If
a particular display is being Stored repeatedly, change the
vertical position occasionally to use other portions of the
display area.
3. Do not leave a Stored display on the screen when it is
no longer needed.
4. Operate in the NONSTORE mode unless Storage is
required.

Maintenance—214 Service
Recalibration Information
To ensure accurate measurements, check the calibration
of this instrument after each 1000 hours of operation, or
every six months if used infrequently. In addition, replace-
ment of components may necessitate recalibration of the
affected circuits. The calibration procedure can also be
helpful in localizing certain troubles in the instrument. In
some cases, minor troubles may be revealed or corrected by
recalibration.
Disassembly Instructions
To gain access to the interior of the instrument, unwind
both probe cords and the power cord from the instrument’s
probe wrap at the rear of the 214.
NOTE
The
arrows
on
the
probe
wrap
indicate
the
proper
direction
to
wrap
the
probes
and
power
cord.
See
Fig.
3-1.
Remove the five screws in the bottom cover of the
instrument. See Fig. 3-2. Separate the bottom cover from
the instrument and lay it aside. The Power Supply (A-3)
circuit board, and the batteries, can be lifted up an;d
pivoted out of the way. Most of the internal workings of
the instrument are now accessible for maintenance.
YELLOW GROUND CLIP IS
POSITIONED HERE BEFORE FINAL
WRAP OF THE PROBE
Fig. 3-1. Proper method for wrapping probes.
3-2
REV.
APR
1974
@

SCREWS SECURING :
BOTTOM COVER |
SCREWS SECURING
SIDE PANEL
SCREWS Lounne So
SINGLE SWEEP BOARD 1483-03
Fig.
3-2.
Location
of
screws
securing
bottom
cover,
side
panel,
and
Single
Sweep
board.
(Instrument
shown
upside down.)
For calibration or troubleshooting within the 214, the
Single Sweep (A-4) circuit board should be reconnected to
the Power Supply (A-3) circuit board. This is done by first
removing the front panel pushbuttons by pulling them, one
at a time, until they disconnect from the Single Sweep
(A-4) board. Next, remove the READY light from the front
panel and the two screws securing the Single Sweep (A-4)
board to the Input (A-1) circuit board. (See Fig. 3-2.) Then
properly connect the Single Sweep circuit board to the
Power Supply circuit board.
If access to the front of the Input (A-1) circuit board is
necessary, remove the knobs from all the external control
shafts. Remove the four screws securing the side panel to
the Input circuit board and, with the READY light out of
the front panel, remove the instrument side panel.
REV C DEC 1980
Maintenance—214 Service
NOTE
Secure the Single Sweep board to the Input board
and replace the front panel pushbuttons before
re-assembling the instrument.
TROUBLESHOOTING
Introduction
The following information is provided to facilitate
troubleshooting the 214 Information contained in other
sections of this manual should be used along with the
following information to aid in locating the defective
component. An understanding of the circuit operation is
very helpful in locating troubles. See the Circuit
Description section for more information.
Troubleshooting Aids
Diagrams. Complete circuit diagrams are given on
foldout pages in the Diagrams section. The component
number and electrical value of each component in this
instrument are shown on the diagrams (see first page of
the Diagrams section for definition of the reference
designators used to identify components in this instru-
ment). Important voltages and waveforms are also shown
on the diagrams. The portions of the circuit mounted
on circuit boards are enclosed with blue lines.
Troubleshooting Equipment
The majority of troubleshooting to be done on the
214 can be accomplished with a 20,000 ohms/volt VOM
such as a Triplett Model 630-NA or a Simpson Model
262. Use a dynamic transistor tester such as a Tektronix
Type 577 Transistor-Curve Tracer to check the semi-
conductor devices used in the 214. To check waveforms
in this instrument, use a test oscilloscope with a DC to
500 kilohertz frequency response and one millivolt to
50 volt/division deflection factor.
CORRECTIVE MAINTENANCE
Obtaining Replacement Parts
Standard Parts. All electrical and mechanical part
replacements for the 214 can be obtained through your
local Tektronix Field Office or representative. However,
many of the standard electronic components can be
obtained locally in less time than is required to order
them from Tektronix, Inc. Before purchasing or ordering
replacement parts, check the parts list for value,
tolerance, rating, and description.
3-3

Maintenance—214 Service
NOTE
When selecting replacement parts, it is important
to remember that the physical size and shape of a
component may affect its performance in the
instrument. All replacement parts should be direct
replacements unless it is known that a different
component will not adversely affect the instrument
performance.
Special Parts. In addition to the standard electronic
components, some special components are used in the
214. These components are manufactured or selected by
Tektronix, Inc. to meet specific performance require-
ments, or are manufactured for Tektronix, Inc. in ac-
cordance with our specifications. Most of the mechanical
parts used in this instrument have been manufactured by
Tektronix, Inc. Order all special parts directly from your
local Tektronix Field Office or representative.
Ordering Parts. When ordering replacement parts from
Tektronix, Inc., include the following information:
1. Instrument type.
2. Instrument serial number.
3. A description of the part (if electrical, include
circuit number).
4. Tektronix Part Number.
WARNING i
Disconnect
the
instrument
from
any
external
power
source before replacing
components.
Component Replacement
Circuit Board Replacement. If a circuit board is
damaged beyond repair, the entire assembly including all
soldered on components can be replaced. Part numbers
are given in the Mechanical Parts List for the completely
wired board.
ee
COLLECTOR” EMITTER
SCREW MOUNTED
SOURCE
L__ buat ret
| TRANSISTORS
INTEGRATED CIRCUITS
|
BASE 2 EMITTER
BASE 1
Q388
N-CHANNEL UNIJUNCTION
a
INDEX INDEX
16 4
1
16-PIN
1483-04
Fig. 3-3. Lead configurations of semiconductors used in this instrument.
3-4
REV E DEC 1981

Transistor Replacement. Transistors should not be
replaced unless actually defective. If removed from. their
sockets during routine maintenance, return them to their
original sockets. Unnecessary replacement of transistors
may affect the callbration of this instrument. When
transistors are replaced, check the operation of that part
of the instrument which may be affected.
Replacement transistors should be of the original
type or a direct replacement. Fig. 3-3 shows the lead
configuration of the transistors used in this instrument.
Some plastic case transistors have lead configurations
which do not agree with those shown here. If a transis-
tor is replaced by a transistor which is made by a
different manufacturer than the original, check the
manufacturer’s basing diagram for correct basing. All
transistor sockets in this instrument are wired for the
basing used for metal-case transistors.
An extracting tool should be used to remove the 14- and
16-pin flat integrated circuits to prevent damage to the
pins. If an extracting tool is not available when removing
one of these integrated circuits, pull slowly and evenly on
both ends of the device. Avoid having one end of the |.C.
disengage from the socket before the other, as the pins may
be damaged. When replacing semiconductors, key the
semiconductor’s index with that of the socket. Failure to
do so will result in damaged components.
Rotary Switches. Individual parts of the VOLTS/DIV
and SEC/DIV rotary switches are replaceable. Refer to
the Parts List for the applicable part numbers for
replacement parts.
Power Supply Capacitors. When operating the instru-
ment from power sources other than 115 VAC 60 Hz, it is
necessary to change the electrical value of capacitors C210
and C212 to maintain proper current levels to the batteries.
Refer to Table 3-1 for the correct values of capacitance for
three of the more commonly used line voltage/line fre-
quency combinations.
TABLE 3-1
POWER SUPPLY CAPACITORS
Capacitor Values
C210 - C212
Nominal Power Line
Voltage/Frequency
110 to 126 VAC 3.3 UF, 10%, 200
58 to 62 Hz VDC Tektronix
(Standard) PN 285-0925-00
90 to 110 VAC 4 uF, 10%, 200
48 to 52 Hz VDC Tektronix
(Option 2) PN 285-0935-00
220 to 250 VAC 2 uF, 10%, 400
48 to 52 Hz VDC Tektronix
(Option 1) PN 285-0933-00
REV F DEC 1981
Maintenance—214 Service
Due to the capacitive power line circuit, sudden
voltage changes may cause damaging current tran-
sients. Avoid operating this instrument from square-
wave inverter supplies, or other sources that produce
large voltage transients.
Selection of capacitor values for other line voltage/line
frequency combinations is illustrated by the graphs in Figs.
3-4 and 3-5. For example, if the instrument is to be oper-
ated on a 60 Hz line, the graph in Fig. 3-5 illustrates the
minimum and maximum line voltage limits, with respect
to the 3.3 uF capacitance values, for proper operation of
the instrument. It also provides information for selecting
values of C210 and C212 for other line voltages. Fig. 3-4
provides 50 Hz information. These capacitors should be
selected from a type suitable for AC operation and voltage
ratings should be at least 1.414 times the value of the
applied line voltage.
C204 and C215 values must be changed from the
nominal value only when the instrument is to be operated
from other than 115V 50 Hz or 115V 60 Hz power line. For
240V 50 Hz operation, C204 and C215 should be replaced
with .001 uF 3kV capacitors.
Selectable Components. Resistor R388 value is
selected for a switching unblanked trace height of no more
than 1.5 divisions for each channel and minimum intensity
change when changing sweep speeds from 5 ms to 2 ms.
The value of R388 is selected from a range of 270, 300, or
330 O as follows:
1. Install a 270 Q resistor for R388, turn the 214 on,
set SEC/DIVto.5 s, andset INTENSITY to maximum
(fully clockwise).
2. The traces will show as dots. Set CH 1 POS to place
the CH 1 dot to the top horizontal graticule line and
set CH 2 POS to place the CH 2 dot to the bottom
horizontal graticule line.
3. Check that no more than 1.5 divisions of unblanked
trace extends vertically from each dot.
4. If each unblanked trace exceeds 1.5 vertical
divisions, turn off the 214, install the next larger size
for R388, recheck and repeat steps 2 through 4 until
unblanked traces are no more than 1.5 divisions
high while maintaining minimum intensity change
when switching sweep speed from 5 ms to 2 ms.
3-5

Maintenance—214 Service
Recalibration After Repair
After any electrical component has been replaced, the
calibration of that particular circuit should be checked,
as well as the calibration of other closely related
circuits. Since the power supply affects all circuits,
calibration of the entire instrument should be checked if
work has been done in the supply.
Instrument Repackaging
If the Tektronix instrument is to be shipped to a Tektronix
Service Center for service or repair, attach a tag showing:
owner (with address) and the name of an individual at your
firm that can be contacted, complete instrument serial
number and a description of the service required.
3-6
Save and re-use the package in which your instrument was
shipped. If the original packaging is unfit for use or not
available, repackage the instrument as follows:
Surround the instrument with polyethylene sheeting to
protect the finish of the instrument. Obtain a carton of
corrugated cardboard of the correct carton strength and
having inside dimensions of no less than six inches more
than the instrument dimensions. Cushion the instrument
by tightly packing three inches of dunnage or urethane
foam between carton and instrument, on all sides. Seal
carton with shipping tape or industrial stapler.
The carton test strength for your instrument is 200 pounds.
REV E DEC 1981

Maintenance—214 Service
240 —# 242 VAC
220
ano
Current
too
high
to operate scope
190
VAC
in
non-store
mode,
without
over charging batteries.
180
o
n
{te
a
aH
oO e 160
7 oO
wu
>
2uF
2uF
22 -10% =fH+10%
= 140 2 LF
TION 1
Current too low
120 to operate scope
in store mode, without
discharging batteries.
100
VALUES OF C210 AND C212 IN uF.
80
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Fig. 3-4. Selecting power supply capacitors for 48 to 52 Hz sinewave operation.
240
220
Current too high
to operate scope
200 in non-store mode,
without over charging
batteries.
180
3.3 uF
STANDARD
160
3.3
uF
-10%
3.3
uF
+10%
LINE
VOLTAGE
IN
VOLTS
RMS
140
Current too low 126 VAC
120 | to operate scope
in store mode,
without discharging
batteries.
104 VAC
100
VALUES OF C210 AND C212 IN uF. :
80
1.5 2.0 2.5 3.0 3.5 4.0 5.0
Fig. 3-5. Selecting power supply capacitors for 58 to 62 sinewave operation.
@ DEC 1980 3-7

Section 4—214 Service
CALIBRATION
General
To ensure instrument accuracy, check the calibration of
the 214 every 1000 hours of operation, or every six months
if used infrequently. Before complete calibration, thor-
oughly clean and inspect this instrument as outlined in the
Preventive Maintenance section.
Tektronix, Inc., provides complete instrument repair and
recalibration at local Field Service Centers and the Factory
Service Center. Contact your local Tektronix Field Office
or representative for further information.
Completion of each step in the Calibration procedure
ensures that this instrument meets. the electrical
specifications given in the INTRODUCTION of this
manual. Where possible, instrument performance is checked
before an adjustment is made. For best overall
performance, make each adjustment to the exact setting
even if the CHECK— step is within the allowable tolerances.
TEST EQUIPMENT REQUIRED
The following test equipment and accessories, or their
equivalent, are required for complete calibration of the
214. Given specifications for the test equipment are the
minimum necessary for accurate calibration. Therefore, the
specifications of any test equipment must either meet or
exceed those listed below. All test equipment is assumed to
be correctly calibrated and operating within the listed
specifications. Detailed operating instructions for the test
units are not given in this procedure. Refer to the
instruction manual for the test equipment if more infor-
mation is needed.
Special Calibration Fixtures
Special Tektronix Calibration fixtures are used in this
procedure only where they facilitate instrument calibration.
These special calibration fixtures are available from
Tektronix, Inc. Order by part number through your local
Tektronix Field Office or representative.
TABLE 4-1
Test Equipment
Description Minimum Specifications
Usage Example
1. DC Voltmeter Range, zero to 1000 volts;
accuracy, within 3%; input
impedance, 20,000 92/volt.
Power Supply output level
checks, CRT Grid Bias, Stor-
age Level adjustments. Verti-
cal and horizontal centering
adjustments.
a
b
. Triplett Model 630-NA.
. Simpson Model 262.
2. Low-Frequency
Constant-Amplitude
Signal Generator
Frequency, one kilohertz to
500 kilohertz; output ampli-
tude, at least 200 millivolts.
Storage Enhance Level adjust-
ment. Vertical amplifier
bandwidth and trigger opera-
tion checks.
. General Radio 1310-B Oscillator.
3. Standard Ampli-
tude Calibrator
Amplitude accuracy, 0.25%;
signal amplitude, five milli-
volts to 100 volts; output
signal, one-kilohertz square
wave.
Vertical and horizontal gain
checks and adjustments.
.. Tektronix Part No. 067-0502-01.
4-1