Tektronix 212 schematic

TECHNICAL MANUAL

OPERATOR, ORGANIZATIONAL, DIRECT SUPPORT,

AND GENERAL SUPPORT

MAINTENANCE MANUAL

(INCLUDING REPAIR PARTS)

FOR

OSCILLOSCOPE, TEKTRONIX, MODEL 212

NSN 6625-01-061-5519

MULTIPLE LAUNCH ROCKET SYSTEM

TM 9-6625-646-14&P

DEPARTMENT OF THE ARMY

JUNE 1984

TM 9-6625-646-14&P

WARNING

DANGEROUS VOLTAGE

is used in the operation of this equipment

DEATH ON CONTACT

may result if personnel fail to observe safety precautions

Never work on electronic equipm ent unless ther e is another per son near by who is familiar
with the operation and hazards of the equipment and who is com petent in administering
first aid. When the technician is aided by operators, he must warn them about dangerous
areas.

Whenever poss ible, the power supply to the equipment must be s hut off befor e beginning
work on the equipment. Tak e particular care to ground every capacitor likely to hold a
dangerous potential. When working inside the equipment, after the power has been
turned off, always ground every part before touching it.

Be careful not to contact high-voltage connections when installing or operating this
equipment.

Whenever the nature of the operation permits, keep one hand away from the equipment
to reduce the hazard of current flowing through vital organs of the body.

WARNING

Do not be misled by the term "low voltage." Potentials as low as 50 volts may
cause death under adverse conditions.

COMMON and probe ground straps are electr ically connected. Theref ore, an elevated
reference applied to any is present on each - as indicated by the yellow warning bands
under the probe retractable hook tips.

For Artificial Respiration, refer to FM 21-11.

EXTREMELY DANGEROUS POTENTIALS

greater than 500 volts exist in the following units:

1. CRT Power Supply

2. Horizontal Deflection System

3. Vertical Deflection System

a/(b blank)

TM 9-6625-646-14&P

Copyright 1972 by Tektronix, Inc. All rights reserved. REPRODUCED BY PERMISSION OF TEKTRONIX, INC. Distribution is limited
to use in connection with the Multiple Launch Rocket System.

Technical Manual HEADQUARTERS

DEPARTMENT OF THE ARMY

No. 9-6625-646-14&P Washington, D.C.,

8 June 1984

Operator’s, Organizational, Direct Support, and

General Support Maintenance Manual

(Including Repair Parts)

for

OSCILLOSCOPE, TEKTRONIX, MODEL 212

(NSN 6625-01-061-5519)

MULTIPLE LAUNCH ROCKET SYSTEM

REPORTING OF ERRORS

You can help improve this bulletin by calling attention to errors and by
recommending improvements and stating your reasons for the recommendations.
Your letter or DA Form 2028, Recommended Changes to Publications, s hould be
mailed directly to Commander, U.S. Army Missile Command, ATTN: DRSMI­SNPM, Redstone Arsenal, AL 35898. A reply will be furnished to you.

TABLE OF CONTENTS

Page

LIST OF ILLUSTRATIONS............................................................................................................................ iii

SECTION 0. GENERAL INFORMATION.......................................................................................... 0-1

Scope............................................................................................................................ 0-1

Indexes of publications................................................................................................. 0-1

SECTION 1. INTRODUCTION.......................................................................................................... 1-1

Option information........................................................................................................ 1-4

Accessories.................................................................................................................. 1-5

Manual change information.......................................................................................... 1-6

Calibration test equipment replacement....................................................................... 1-7

SECTION 2. FUNCTIONS OF CONTROLS AND CONNECTORS.................................................. 2-1

SECTION 3. PREVENTIVE MAINTENANCE.................................................................................... 3-1

Disassembly instructions.............................................................................................. 3-1

Cleaning........................................................................................................................ 3-1

Visual inspection........................................................................................................... 3-1

Semiconductor checks................................................................................................. 3-2

Recalibration................................................................................................................. 3-2

This manual is, in part, authenticated manufacturer’s commercial literature. A Maintenance Allocation Chart and Recommended Spare
Parts List has been added to supplement the commercial literature. The format of this manual has not been structured to consider
levels of maintenance.

i

TM 9-6625-646-14&P

SECTION 4. CALIBRATION................................................................................................................ 4-1

Test equipment required................................................................................................. 4-1

Preliminary procedure..................................................................................................... 4-3

Preliminary control settings............................................................................................. 4-3

Procedure ....................................................................................................................... 4-4

SECTION 5. TROUBLESHOOTING AIDS.......................................................................................... 5-1

Component color-code ................................................................................................... 5-1

Semiconductor lead configurations ................................................................................ 5-2

Equipment recommended .............................................................................................. 5-2

SECTION 6. CIRCUIT DESCRIPTION................................................................................................ 6-1

Block............................................................................................................................... 6-1

Circuit operation.............................................................................................................. 6-1

SECTION 7. CORRECTIVE MAINTENANCE..................................................................................... 7-1

Obtaining replacement parts........................................................................................... 7-1

Component replacement ................................................................................................ 7-1

Instrument repackaging.................................................................................................. 7-4

SECTION 8. PARTS LIST, DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS .......................... 8-1

Electrical parts list........................................................................................................... 8-2

Mechanical parts list....................................................................................................... 8-12

Exploded drawings.......................................................................................................... 8-17

Circuit board drawings and schematics.......................................................................... 8-19

APPENDIX A. REFERENCES ........................................................................................... A-1

B. MAINTENANCE ALLOCATION CHART (MAC)......................................... B-1

C. RECOMMENDED REPAIR PARTS LIST................................................... C-1

ii

TM 9-6625-646-14&P

LIST OF ILLUSTRATIONS

Figure Title Page

1-1 212 Oscilloscope. 0-1
1-2 212 Oscilloscope Accessories. 1-5
2-1 Side Panel Controls and Connectors. 2-1
3-1 Location of Screws Securing Bottom Cover and Side Panel. 3-1
3-2 Location of Circuit Boards Within the 212. 3-2
4-1 Location of Power Supply Test Points and CRT Grid Bias

Adjustment. 4-4
4-2 Location of Trace Rotation Adjustment. 4-4
4-3 Location of Vertical Centering Adjustment and Test Point. 4-5
4-4 Location of Attenuator Compensation Capacitors. 4-7
4-5 Location of Horizontal Centering Adjustment and Test Point. 4-10
5-1 Color Code for Resistors, Ceramic Capacitors, and Dipped Tantalum

Electrolytic Capacitors. 5-1
5-2 Lead Configuration of Semiconductors Used in this Instrument. 5-2
6-1 Vertical Input Amplifiers Detailed Block Diagram. 6-2
6-2 Vertical and Horizontal Output Amplifiers Detailed Block Diagram. 6-3
6-3 Trigger/Sweep Generator Detailed Block Diagram. 6-4
6-4 Power Supply Detailed Block Diagram. 6-5
6-5 CRT Circuit Detailed Block Diagram. 6-6
7-1 Selecting C210 and C212 Capacitance Values for 48 to 52

Hz Operation. 7-2
7-2 Selecting C210 and C212 Capacitance Values for 58 to 62

Hz operation. 7-3
8-0 Mechanical Parts, Exploded View. 8-17

8-1 Block Diagram. 8-19
8-1A Al Input Circuit Board (Front). 8-21
8-1B Al Input Circuit Board (Near). 8-21
8-1C Waveform Conditions - Vertical Amplifier. 8-23
8-1D Vertical Amplifier Schematic Diagram. 8-23
8-1E Vertical Amplifier Schematic Diagram. 8-25
8-2 A2 Amplifier Circuit Board. 8-25
8-2A Waveform Conditions - Horizontal and Vertical Output Sweep

and Trigger. 8-27
8-2B Horizontal and Vertical Output Sweep and Trigger

Schematic Diagram. 8-27
8-3A A3 Power Supply Circuit Board, SN B040000-up. 8-29
8-3B A3 Power Supply Circuit Board, below SN B040000. 8-31
8-4 CRT Circuit Schematic Diagram. 8-33
8-5 Power Supply Schematic Diagram. 8-35

iii

SECTION 0 GENERAL INFORMATION

TM 9-6625-646-14&P

O-1. Scope. This manual contains instructions for the

operator, organizational, direct support, and general
support maintenance of and calibration procedures for
Tektronix Oscilloscope, Model 212. Throughout this
manual, Tektronix Oscilloscope, Model 212 is referred
to as the 212.

O-2. Indexes of Publications.
Refer to the latest issue of DA Pam 310-4 to determine
whether there are new editions, changes, or additional
publications pertaining to Tektronix Oscillos cope, Model

212.

b. DA Pam 310- 7.

Pam 310-7 to determine whether there are modification
work orders (MWO’s) pertaining to Tektronix
Oscilloscope, Model 212.

O-3. Forms, Records, and Reports. Department of
Army forms and procedures used for equipment
maintenance and calibration are those prescr ibed by TM
38-750, The Army Maintenance Management System.
Accidents involving injury to personnel or damage to
materiel will be reported on DA Form 285, Accident
Report, in accordance with AR 385-40.

Refer to the latest issue of DA

a. DA Pam 310-4.

O-4. Reporting Equipment Improvement
Recommendations (EIR). If your 212 needs

improvement, let us know. Send us an EIR. You, the
user, are the only one who can tell us what you don’t like
about your equipment. Let us know why you don’t like
the design. Tell us why a procedure is hard to perform.
Put it on an SF 368 (Quality Deficiency Report). Mail it to
Commander, U.S. Army Missile Command, ATTN:
DRSMI-SNEM, Redstone Arsenal, AL 35898. We’ll send
you a reply.

O-5. Administrative Storage. To prepare the Tektronix
Oscilloscope, Model 212 for placement into and removal
from administrative storage, refer to Section 3, Chapter
4, AR 750-25-1, Maintenance of Equipment and
Supplies. Temporary storage should be acc omplished in
accordance with TB 750-25-1, Section 2, Maintenance
of Supplies and Equipment.

O-6. Destruction of Army Electronics Materiel.

Destruction of Tektronix Oscilloscope, Model 212 to
prevent enemy use shall be in accordance with TM 43­0002-26, Organizational Maintenance Manual,
Destruction of Equipment to Prevent Enemy Use for
Launcher, Rocket, Armored Vehicle Mounted: XM270,
Multiple Launch Rocket System.

0-1

Figure 1-1. 212 Oscilloscope.

0-2

TM 9-6625-646-14&P

SECTION 1

INTRODUCTION

TM 9-6625-646-14&P

The 212 Oscilloscope is a dual-channel portable
oscilloscope using all solid state and integrated circuitr y
(except the CRT). The s m all size of the 212 m ak es it an
extremely portable oscilloscope for on-location
maintenance in many fields of application.

The 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
two integral high-impedance probes. Both single-trace
and dualtrace modes of operation are offered. Single­trace displays are achieved by turning off either ver tical
channel with its position control. In the dual-trace mode,
the instrument automatically chops or alternates,
depending upon the sweep rate. The trigger circuits
provide stable triggering over the full bandwidth
capabilities of the vertical system.

The horizontal deflection system provides calibrated
sweep rates from 500 millisec onds to five m icrosec onds/
division. It also provides uncalibrated sweep rates, via a
variable sweep magnifier, to at least five times the
indicated sweep rate for a maximum of at least one
microsecond/ division. In addition, X-Y operation is
provided. Channel 1 supplies the horizontal (X)
deflection, with a range from less than one millivolt to 50
volts/division (at a reduced bandwidth of 50 kilohertz),
and Channel 2 the vertical (Y) deflection. The resultant
CRT display is presented on a 6 X 10 divis ion graticule
(each division equals 0.203 inch).

The 212 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.

This instrument will meet the following electrical
characteristics after complete instrument calibration.
These characteristics apply over an ambient temperature
of -15àC to +55àC (+5àF to +131àF), except as
otherwise indicated. W armup time for given accuracies
is five minutes.

VERTICAL DEFLECTION SYSTEM

Calibrated Range: One millivolt to 50 volt/division. 15

steps in 1-2-5 sequence.

Accuracy: Within 5% with VOLT S/DIV VAR control in

CAL position and gain correctly set at 5 mV/div.

Uncalibrated (variable) Range: Continuously variable
between calibrated settings. Extends maximum
deflection factor to at least 125 volts/division.

BANDWIDTH (with 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 2 hertz at all deflection factors.

INPUT RESISTANCE:

Approximately one megohm.
INPUT CAPACITANCE:

1 mV/DIV to 50 mV/DIV: Approximately 160
picofarads.

100 mV/DIV to 50 V/DIV: Approximately 140
picofarads.

MAXIMUM USABLE INPUT VOLTAGE:

50 V/DIV to .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 2 kilohertz or risetime not less than 100
nanoseconds.

CHOPPED MODE:

From 500 ms/DIV to 2 ms/DIV of time base at
approximately 50 kilohertz.

ALTERNATE MODE:

From 1 ms/DIV to 5ps/DIV of time base.
INPUT IMPEDANCE MATCHING:

Matched to within approximately 10%.

DEFLECTION FACTOR:

1-1

TM 9-6625-646-14&P

GAIN ACCURACY BETWEEN CHANNELS:

Within 5% with both VOLTS/DIV VAR 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:

1.0 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 kilohertz.

EXTERNAL TRIGGER:

Input Resistance: Approximately one megohm.
Input Capacitance: Approximately 30 picofarads.
Maximum Usable Input Voltage: 8 volts (DC + peak

AC) 16 volts peak-to-peak AC (one megahertz or less).

calibrated settings. Extends maxim um sweep rate to at
least 1.0 microsecond/division.

CH 1 HORIZONTAL INPUT:

Calibrated Deflection Factor: 1 millivolt to 50 volts/
division.

Variable: At least five times (using HORIZ MAG).

Accuracy: Within 10% (with HORIZ MAG control in
CAL position).

X-Y Phasing: Less than 3à at five kilohertz.

Maximum Input Voltage: 600 volts (DC + peak AC) ;
600 volts (peak-to-peak AC).

DISPLAY

GRATICULE:

Type: Internal black line, non-illuminated.

Area: Six divisions vertical by 10 divisions horizontal.
Each division equals 0.203 inch.

PHOSPHOR:

P31 Standard.

ISOLATION

HORIZONTAL DEFLECTION SYSTEM

SWEEP RATE:

Calibrated Range: 500 milliseconds to five

microseconds/ division. 16 steps in 1-2-5 sequence.

Accuracy (over center eight divisions): Within 5%
with HORIZ MAG control in CAL position and timing
correctly set at 1 ms/DIV (disregard f irs t 0.5 microsecond
of total sweep length).

Linearity (any two division portion within center eight
divisions): W ithin 5% (disregard f irst 10% of total sweep
length).

Variable Magnifier: Continuously variable between

PROBE COMMON TO 212 CASE EXTERIOR: (When
battery operated with AC power plug secured in the
insulated cover.) Maxim um s afe potential between pr obe
common (floating circuit ground) and 212 case exterior
not to exceed 500 V RMS sinusoidal, or 700 V (DC +
peak AC).

PROBE COMMON TO AC LINE: Maximum safe
potential between probe common (f loating c irc uit ground)
and the AC power line is not to exceed 250 V RMS
sinusoidal minus the AC power line RMS voltage. (i.e.,
when the AC power line RMS voltage is 117 V, the
maximum allowable potential on the probe common is
250 -117 = 133 V RMS.)

1-2

AC OPERATION

CAUTION
Due to the capacitive line input
circuit, sudden voltage changes may
cause damaging input current
transients. Avoid operating this
instrument from squarewave inverter
supplies, or other sources that
produce large voltage transients.

LINE VOLTAGE RANGE: 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.

TM 9-6625-646-14&P

CHARGE OPERATING TEMPERATURE
TEMPERATURE 15°C +20°C to +30°C +55°C

(+5°F) (+68°F to +860F) (+131°F)

0°C (+32°F) 40% 60% 50%
+20àC to +30àC 65% 100% 85%
(+68° F to +86à F)
40°C (+104àF) 40% 65% 55%

GENERAL

ENVIRONMENT:

Temperature:

LINE FREQUENCY: 58 to 62 hertz.

NOTE
Refer to Option and Corrective
Maintenance information for other
line voltages and frequencies.

MAXIMUM POWER CONSUMPTION: Three watts or
less at 126 volts, 60 hertz.

INTERNAL BATTERY OPERATION

BATTERIES: 10 rechargeable A nickel-cadmium cells.
CHARGE TIME (from AC line): 16 hours f or full charge

(instrument off during charge cycle).
POWER (BAT TERY) INDICATOR: When ex tinguished,

indicates less than 10 minutes of sc ope operating life left
in the batteries.

BATTERY EXCESSIVE DISCHARGE PROTECTION:
Instrument 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 +20àC to +30àC):
Three to five hours. Longest operating tim e provided at
lower trace intensity.

Operating from Batteries , -15°C to +55 àC (+5àF to

+131àF).

Charging or operating from AC line, 0°C to +40°C

(+32°F to +104àF).

Storage, -40àC to +60°C (-40àF to +140à F).

Altitude:

Operating, to 25, 000 feet (maximum operating
temperature decreased by 10C per 1, 000 f eet above 15,
000 feet).

Non-operating, to 50, 000 feet.

Humidity (operating and non-operating): 5 cycles
(120 hours) to 95% relative humidity referenced to
MIL-E-16400F.

Shock (operating and non-operating): Tested with
two shocks at 150 g, one-half sine, two millisecond
duration each direction along three major axes.

WEIGHT (without accessories):

3.4 pounds (1.5 kilograms)

DIMENSIONS (measured at maximum points):

TYPICAL CHARGE CAPACITY (reference to charge/
discharge at +20àC to +30àC):

Height: 3.0 inches (7.6 centimeters).

Width: 5.25 inches (13.2 centimeters).

Depth: 8.9 inches (22.6 centimeters).

1-3

TM 9-6625-646-14&P

OPTION INFORMATION

Your instrument may be equipped with one or more options. T his s ection desc ribes thos e options or dir ects the reader

to where the option is documented.

OPTION 1

Option 1 equips the 212 for operation from a 220 to 250 V ac 48 to 52 Hz power line source. O ption 1 parts values that
differ from the standard 212 are listed here. A power cord cable assembly, for adapting to appropriate power plugs, is
included with Option 1 instruments. Refer to the Corrective Maintenance and Diagrams sections of this manual for
additional information concerning Option 1.

ELECTRICAL PARTS LIST DIFFERENCES FOR OPTION 1

A3 670-2405-21* POWER SUPPLY Circuit Board Assembly (Option 1)
C204 283-0279-00 0.001 UF, 20%, 3 KV
C210 285-0932-00 1.0 UF, 10%, 400V
C212 285-0933-00 2.0 UF, 10%, 400V
C215 283-0279-00 0.001 UF, 20%, 3 KV

ADDITIONAL STANDARD ACCESSORIES FOR OPTION 1

161-0077-01 CABLE ASSEMBLY, POWER

(Adapts to users plug type)

*In some Option 1 instruments, the suffix number on the board may not be marked -21.

OPTION 2

Option 2 equips the 212 for operation from a 90 to 110 V ac 48 to 52 Hz power line source. Option 2 parts values that
differ from the standard 212 are listed here. Refer to the Corr ective Maintenance and Diagrams s ections of this manual
for additional information concerning Option 2.

ELECTRICAL PARTS LIST DIFFERENCES FOR OPTION 2

A3 670-2405-31 ** POWER SUPPLY Circuit Board Assembly (Option 2)
C210 285-0934-00 2.2 UF, 10%, 200V
C212 285-0935-00 4.4 UF, 10%, 200V

**ln some Option 2 instruments, the suffix number on the board may not be marked -31.

1-4

TM 9-6625-646-14&P

Fig. &

Index Tektronik Serial/Model No. Mfr
No. Part No. Eff Dscont Qty 1 2 3 4 5 Name & Description Code Mfr Part Number

-1 015-0199-01 1 VISOR, CRT: 80009 016-0199-01

-2 016-0512-00 1 CASE, CARRYING: 80009 016-0512-00

-3 346-0104-00 1 STRAP, CARRYING: 17516 4188-BA

-4 159-0121-00 2 FUSE, CARTRIDGE :DIN, 0.4A, 250V,5 SEC 75915 212.400
070-1375-00 1 MANUAL, TECH: OPERATORS 80009 070-1375-00
070-1376-00 1 MANUAL, TECH: INSTRUCTION 80009 070-1376-00

Figure 1-2. 212 Oscilloscope Accessories

1-5

TM 9-6625-646-14&P

MANUAL CHANGE INFORMATION

At Tektronix, we continually strive to keep up with latest electronic developments by adding circuit and component

improvements to our instruments as soon as they are developed and tested.

Sometimes, due to printing and s hipping requirements, we can’t get these changes imm ediately into printed manuals.

Hence, your manual may contain new change information on following pages.

A single change may affect sever al sections. Since the change inform ation sheets are c arried in the manual until all
changes are permanently entered, some duplic ation may occur. If no such change pages appear following this page, your
manual is correct as printed.

SERVICE NOTE

Because of the universal parts procurement problem, some electrical parts in your instrument may be different
from those described in the Replaceable Electrical Parts List. The parts used will in no way alter or compromise
the performance or reliability of this instrument. They are installed when necessary to ensure prompt delivery to
the customer. Order replacement parts from the Replaceable Electrical Parts List.

1-6

TM 9-6625-646-14&P

CALIBRATION TEST EQUIPMENT REPLACEMENT

Calibration Test Equipment Chart

This chart compares TM 500 produc t perform ance to that of older Tek tronix equipm ent. Only those characteris tics where
significant specification differences occur, are listed. In some cases the new instrument may not be a total functional
replacement. Additional support instrumentation may be needed or a change in calibration procedure may be necessary.

Comparison of Main Characteristics

DM 501 replaces 7D13
PG 501 replaces 107 PG 501 - Risetime less than 3.5 ns into 107 - Risetime less than 3.0 ns into

108 PG 501 - 5 V output pulse; 3.5 ns Risetime. 108 - 10 V output pulse; 1 ns Risetime.
111 PG 501 - Risetime less than 3.5 ns; 8 ns 111 - Risetime 0.5 ns; 30 to 250 ns

114 PG 501 + 5 V output. 114 - ±10 V output. Short proof output.
115 PG 501 - Does not have Paired, Burst, Gated, 115 - Paired, Burst, Gated, and Delayed

PG 502 replaces 107

108 PG 502 - 5 V output 108 - 10 V output.
111 PG 502 - Risetime less than 1 ns; 10 ns 111 - Risetime 0.5 ns; 30 to 250 ns

114 PG 502 -+5 V output 114 - 10 V output. Short proof output.
115 PG 502 - Does not have Paired, Burst, Gated, 115 - Paired, Burst, Gated, Delayed & Un-

2101 PG 502 - Does not have Paired or Delayed 2101 - Paired and Delayed pulse; 10 V

PG 506 replaces 106 PG 506 - Positive-going trigger output signal 106 - Positive and Negative-going trigger

067-0502-01 PG 506 - Does not have chopped feature. 0502-01 - Comparator output can be alter-

SG 503 replaces 190,

190A, 190B SG 503 - Amplitude range 5 mV to 5.5 V p-p. 190B - Amplitude range 40 mV to 10 V p-p.

191 SG 503 - Frequency range 250 kHz to 250 MHz. 191 - Frequency range 350 kHz to 100 MHz.

067-0532-01 SG 503 - Frequency range 250 kHz to 250 MHz. 0532-01 - Frequency range 65 MHz to 500

TG 501 replaces 180,

180A TG 501 - Marker outputs, 5 sec to 1 ns. 180A - Marker outputs, 5 sec to 1 us.

181 TG 501 - Marker outputs, 5 sec to 1 ns. Sine- 181 - Marker outputs, 1, 10, 100, 1000,
184 TG 501 - Marker outputs, 5 sec to 1 ns. Sine- 184 - Marker outputs, 5 sec to 2 ns. Sine-

2901 TG 501 - Marker outputs, 5 sec to 1 ns. Sine- 2901 - Marker outputs, 5 sec to 0.1 us.

50Ω.50Ω.

Pretrigger pulse delay. Pretrigger Pulse delay.

or Delayed pulse mode; +5 V dc pulse mode; +
Offset. Has +5 V output. Short-proof output.

Pretrigger pulse delay. Pretrigger pulse delay.

Delayed & Undelayed pulse mode; delayed pulse mode; +10 V output.

Has ±5 V output. Short-proof output.
pulse. Has ±5 V output. output.
at least 1 V; High Amplitude out- output signal, 50 ns and 1 V; High

put, 60 V. Amplitude output, 100 V.

nately chopped to a reference
voltage.

MHz.

Sinewave available at 5, 2, and 1 ns. Sinewave available at 20, 10,
Trigger output - slaved to marker and 2 ns. Trigger pulses 1, 10,
output from 5 sec through 100 ns. 100 Hz; 1, 10, and 100 kHz.
One time-mark can be generated at a Multiple time-marks can be
time. generated simultaneously.

wave available at 5, 2, and 1 ns. and 10, 000 us, plus 10 ns sinewave.
wave available at 5, 2, and 1 ns. wave available at 50, 20, 10, 5,

Trigger output - slaved to marker and 2 ns. Separate trigger pulses
output from 5 sec through 100 ns. of 1 and .1 sec; 10, 1, and .1 ms;
One time-mark can be generated at 10 and 1 /s. Marker amplifier pro­a time. vides positive or negative time

marks of 25 V min. Marker
intervals of 1 and .1 sec; 10, 1,
and .1 ms; 10 and 1 us.

wave available at 5, 2, and 1 ns. Sinewave available to 50, 10,
Trigger output - slaved to marker and 5 ns. Separate trigger
output from 5 sec through 100 ns pulses, from 5 sec to 0.1 us.
One time-mark can be generated at Multiple time-marks can be gene­a time. rated simultaneously.

10 V output.

NOTE: All TM 500 generator outputs are short-proof. All TM 500 plug-in instruments require TM 500-Series
Power Module.

1-7

TM 9-6625-646-14&P

1-8

SECTION 2

FUNCTIONS OF CONTROLS AND CONNECTORS

TM 9-6625-646-14&P

The controls and connectors neces sary for operation
of the 212 are located on the right side of the instrument.
(See Fig. 2-1.) The POWER (BATTERY) indicator is on
the front panel. A brief description of each contr ol and
connector is given here.

VOLTS/DIV-selects vertical deflection factor (vertical

VARiable control must be in CAL position for

indicated deflection.
INPUT COUPLING-selects the method used to couple

the channel input signal to the vertical amplifier
system.

AC-the DC component of input signal is blocked.
GND-vertical amplifier input circuit is grounded.

The applied input signal is connected to ground
through a one megohm 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 input.

STEP ATTEN BALance-a screwdriver adjustment to

balance the vertical amplifier system for minimum
trace shift when switching deflection factors.

Vertical POSition-controls the vertical position of the

appropriate trace. OFF detent turns the channel
off.

VOLTS/DIV VARiable-provides a continuously variable

deflection factor between the calibrated settings of
the VOLTS/DIV switch for the appropriate vertical
channel.

VERTical GAIN-screwdriver adjustment to set the gain of

the vertical amplifier system.

AUTO PRESET-screwdriver adjustment to set the AUTO

PRESET trigger point for automatic trigger
operation.

Trigger SOURCE-selects the source of the trigger signal.

COMP-the sweep is triggered from a sample of
the vertical deflection signal after the vertical
switching.

CH 2-the sweep is triggered from a sample of
the vertical deflection signal before the vertical
switching and only from CH 2.

EXT-the sweep is triggered from the signal
applied to the EXT TRIG banana jack.

Figure 2-1. Side Panel controls and connectors.

2-1

LEVEL/SLOPE-selects the amplitude point and the s lope

of the trigger signal on which the sweep is triggered.

When the indicator dot is to the left of 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 CRT display.

TM 9-6625-646-14&P

Horizontal POSition-controls the horizontal position of the

trace.

SEC/DIV-selects horizontal sweep rate (HORIZ MAG

must be in CAL position for indic ated sweep rate) X-Y
position allows for X-Y operation; CH 2 supplies the
vertical deflection and CH 1 the horizontal deflection.

EXT TRIG-banana jack for input of an external trigger

signal.

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 adjustm ent to obtain a well-defined

display.
HORIZontal MAGnifier-provides continuously variable

sweep magnification to a max imum of approxim ately

five times the sweep rate indicated by the SEC/DIV

switch.
HORIZontal GAIN-screwdriver adjustment to set the

basic gain of the horizontal amplifier system.

COMMON-banana jack to establish common ground

between the 212 and the external signal source or
equipment under test.

WARNING
COMMON and probe ground straps
are electrically connected. Therefore,
an elevated reference applied to any
is present on each - as indicated by
the yellow warning bands under the
probe retractable hook tips.

POWER ( BATTERY) Indicator-red light to indicate when

the instrument is on. When light extinguishes, less
than 10 minutes of operating life remain.

2-2

SECTION 3

PREVENTIVE MAINTENANCE

Preventive maintenance, when performed on a
regular basis, can prevent instrument breakdown and
may improve the reliability of this instrument. The
severity of environment to which the 212 is subj ected will
determine the frequency of maintenance. A convenient
time to perform preventive maintenance is preceding
recalibration of the instrument.

Disassembly

To gain access to the interior of the instrument,
unwind both the probe cords and the power cord from
the rear of the instrument. Remove the five screws in
the bottom cover of the instrument. See Fig. 3- 1. G ently
separate the bottom cover from the instrument and lay
aside. The Power Supply circuit board with the batteries
can be lifted up and pivoted out of the way. Most of the
internal workings of the instrument are now accessible.

If it is necessary to have access to the front of the
Input circuit board, remove the knobs from all of the
external control shafts. Remove the four screws
securing the side panel to the Input circuit board and
remove the instrument side panel.

TM 9-6625-646-14&P

Cleaning

The 212 should be cleaned as often as operating
conditions require. Accumulation of dir t in the inst rument
can cause component breakdown.

The high impact plastic covers provide protection
against dust in the interior of the instrument. Loos e dust
accumulated 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 side-panel controls.
Dirt which remains can be removed with a soft cloth
dampened in a mild detergent and water solution.
Abrasive cleaners should not be used.

It should be only occasionally necessary to c lean the
interior. The best way to clean the interior is to blow off
the accumulated dust with dry, low-velocity air. A
softbristle brush or a cotton-tipped applicator is useful for
cleaning in narrow spaces or for cleaning more delic ate
circuit components.

Figure 3-1. Location of screws securing bottom cover and

side panel.

CAUTION
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.

Visual Inspection

The 212 should be inspected occasionally for such
defects as broken connections, improperly seated
transistors, damaged circuit boards, and heat-damaged
parts.

3-1

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, it is important that the cause of the
overheating be corrected to prevent recurrence of the
damage.

Semiconductor Checks

Periodically checking the semiconductors in the 212 is
not recommended. The best check of semiconductor
performance is actual operation in the instrument. If it is
desired to check the performance of a semiconductor
out of the instrument, a dynamic checker such as a
TEKTRONIX Type 576 Transistor Curve Tracer is
recommended. Lead configurations of the
semiconductors used in the 212 are shown in Fig. 5-2.

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 s lowly and
evenly on both ends of the device. Try to avoid having
one end of the integrated circuit disengage from the
socket before the other, as the pins may be damaged.
When replacing semiconductors, key the
semiconductor’s index with that of its soc ket. Failure to
do so can result in damaged components.

TM 9-6625-646-14&P

Recalibration

To assure accurate measurements, check the
calibration of this instrument after each 1000 hours of
operation or every six months if used infrequently. In
addition, replacement 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.

Figure 3-2. Location of circuit boards within the 212.

3-2

SECTION 4

CALIBRATION

TM 9-6625-646-14&P

General

To assure instrument accuracy, check the calibration
of the 212 every 1000 hours of operation, or every six
months if used infrequently. Before complete calibr ation,
throughly clean and inspect this instrument as outlined in
the Preventive Maintenance section.

The following test equipment and accessories, or their

equivalent, are required for complete calibration of the

212. Given specifications for the test equipment are the
minimum necessary for acc urate calibration. Therefore,
the specifications of any test equipment must either meet

TEST EQUIPMENT REQUIRED

or exceed those listed below. All test equipment is

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.

assumed to be correctly calibrated and operating within
the listed specifications. Detailed operating instruc tions
for the test units are not given in this procedure. Refer to
the instruction manual for the test equipment if more
information is needed.

To aid in locating a step in this procedure, an index is
given prior to the complete procedure. Completion of
each step in the Calibration procedure ensur es that this

Special Calibration Fixtures

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 instrument performance, make each
adjustment to the exact setting even if the CHECK- s tep
is within the allowable tolerances.

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. Time-Mark Generator Marker outputs, 5 microseconds to 0.1 Horizontal timing check a. TEKTRONIX 2901
second; marker accuracy, within 0.1%. and adjustment. Time-Mark Generator.

b. TEKTRONIX 184
Time-Mark Generator.

2. Standard Amplitude Amplitude accuracy, 0.25%; signal Vertical and horizontal a. TEKTRONIX

Calibrator amplitude, 5 millivolts to 100 volts; amplifier gain checks and calibration fixture Part

output signal one-kilohertz square adjustments. Number 067-0502-01.
wave.

3. Square-Wave Frequency, one kilohertz; risetime, Vertical amplifier a. TEKTRONIX Type

Generator 100 nanoseconds or less; output compensation checks and 106 Square-Wave

amplitude, 0.4 volt to 40 volts. adjustments. Generator.

4. Low-Frequency Frequency, one kilohertz to 500 Vertical Amplifier a. General Radio

Constant-Amplitude kilohertz; output amplitude, at least bandwidth check. Trigger 1310-B Oscillator.
Signal Generator 200 millivolts. operation checks.

5. DC Voltmeter Range, zero to 1000 volts; accuracy, Power supply output level a. Triplett Model
within 3%; input impedance, checks. Vertical and 630-NA.
20, 000Ω/volt. horizontal centering

adjustment. CRT grid bias b. Simpson Model 262.
adjustment.

4-1

TM 9-6625-646-14&P

TABLE 4-1 (cont)

Description Minimum Specifications Usage Example

6. Cable Impedance, 50 ohms; type, RG-58/U; External trigger operation a. TEKTRONIX Part
length, 42 inches; connectors, BNC. check. Horizontal gain Number 012-0057-01.

check and adjustment.

7. Adapter Connectors, BNC female and dual External trigger checks. a. TEKTRONIX Part
banana plug. Number 103-0090-00.

8. Adapter Connectors, GR874 and BNC female. Vertical Amplifier a. TEKTRONIX Part

compensation checks and Number 017-0063-00.
adjustment.

9. Termination Impedance, 50 ohms; accuracy, 2%; Vertical amplifier a. TEKTRONIX Part
connectors, BNC. compensation checks and Number 011-0049-01.

adjustment.

10. Attenuator Ratio, 10X; connectors, BNC; Vertical amplifier a. TEKTRONIX Part
impedance, 50 ohms. bandwidth check. Number 011-0059-01.

11. Adapter Connectors, probe tip to BNC. Used throughout a. TEKTRONIX Part

procedure for signal Number 013-0084-01.
interconnection.

12. T-Connector Connectors, BNC. External trigger operation a. TEKTRONIX Part

checks. Number 103-0030-00.

13. Screwdriver Three-inch shaft, 3/32 inch bit. Used throughout a. Xcelite R-3323.

Procedure to adjust
variable resistors.

14. Low-Capacitance 1 1/2-inch shaft. Used to adjust variable a. TEKTRONIX Part

Screwdriver capacitors. Number 003-0000-00.

INDEX TO CALIBRATION PROCEDURE

Power Supply and Display

1. Check Power Supply DC Levels

2. Adjust CRT Grid Bias (internal adjustment of

R273)

3. Adjust FOCUS (external side panel adjustment

of R398)

4. Adjust Trace Rotation (internal adjustment of

R141)

Vertical System Adjustment

5. Adjust Vertical DC Centering (internal

adjustment of R101)

6. Adjust CH 1 STEP ATTENuation BALance

(external

side panel adjustment of R415)

7. Adjust CH 2 STEP ATTENuation BALance

(external side panel adjustment of R315)

8. Adjust VERTical GAIN (external side panel

adjustment of R470)

9. Check CH 2 VARiable VOLTS/DIV Range

10. Check CH 2 VOLTS/DIV Accuracy VOLTS/DIV

Range

11. Check CH 1 VOLTS/DIV Accuracy and VARiable

12. Adjust CH 1 VOLTS/DIV Switch Compensation

(internal side panel adjustment of C407, C408, C409)

13. Adjust CH 2 VOLTS/DIV Switch Compensation

(internal side panel adjustment of C307, C308, C309

14. Check CH 2 Vertical Amplifier Bandwidth

4-2

TM 9-6625-646-14&P

15. Check CH 1 Vertical Amplifier Bandwidth

Trigger Circuit Adjustment

16. Adjust AUTO PRESET (external side panel

adjustment of R375)

17. Check Trigger Circuit Operation

Horizontal System Adjustment

18. Adjust Hor izontal Centering (internal adjustm ent

of R366)

19. Adjust HORIZontal GAIN (external side panel

adjustment of R475)

20. Adjust SWEEP CALibration (external side panel

adjustment of R370)

21. Check HORIZ MAG Range

22. Check SEC/DIV Accuracy

PRELIMINARY PROCEDURE

NOTE
Titles for external controls of this
instrument are fully capitalized in this
procedure (e.g., INTEASITY). Internal
adjustments are initial capitalized
only (e.g., Grid Bias).

PRELIMINARY CONTROL SETTINGS

Preset the instrument controls to the settings given

below when starting a calibration procedure.

Channel 1 Controls

VOLTS/DIV 5 m
VOLTS/DIV VAR CAL
POS Midrange
INPUT COUPLING GND

Channel 2 Controls

VOLTS/DIV 5 m
VOLTS/DIV VAR CAL
POS OFF
INPUT COUPLING GND

This instrument should be adjusted at an ambient

temperature of +250C (+ 50C) for best overall accuracy.

1. Remove the instrument covers as described in
the Disassembly Instructions in the Preventive
Maintenance section.

2. Connect the instr ument to a 117 VAC 60 Hz line
source. If the batteries are not fully charged, leave the
212 connected to the line with the power switch turned
off for a period of approximately one hour before
continuing with calibration.

3. Set the instrument controls as given under
Preliminary Control Settings. Allow at least five minutes
of warmup before proceeding.

Trigger Controls

SOURCE COMP
LEVEL/SOURCE AUTO PRESET

Sweep Controls

SEC/DIV 1 m
HORIZ MAG CAL
POS Midrange

Display Controls

POWER ON
INTENSITY Fully Counterclockwise

4-3

CALIBRATION PROCEDURE

POWER SUPPLY and DISPLAY

Equipment Required

1. DC Voltmeter 2. Three-inch Screwdriver

TM 9-6625-646-14&P

Control Setting

Preset instrument controls to the settings given under

Preliminary Control Settings.

1. Check Power Supply DC Levels

NOTE
If the instrument has been operating
satisfactorily prior to recalibration,
proceed with step 2.

a.Using the DC voltmeter, measure the DC level of
the power supplies given in Table 4-2. Observe proper
meter polarity. See Fig. 4-1 for test point locations.

TABLE 4-2.

Power Supply Accuracy

Supply Measurement

-5.6 volt -5.6 volts ±0.4 volt
+5.6 volt +5.6 volts ±0.4 volt
+65 volt +65 volts ±4 volts

-1000 volt -960 volts ±40 volts
(due to meter loading)

2 of plug P3 (negative meter lead to pin 2) on the Power
Supply Board. See Fig. 4-1.

b.Turn the INTENSITY control fully clockwise.
c.CHECK-Meter reading of +1.9 volts.
d.ADJUST-CRT Grid Bias, R273 (s ee Fig. 4-1) for

a meter reading of +1.9 volts.

e.Disconnect all test equipment. Turn the

INTENSITY control fully counterclockwise.

3. Adjust FOCUS

a.Turn CH 2 POS midrange and CH 1 POS to the

OFF detent.

b.Set the SEC/DIV switch to X-Y and adjust the

INTENSITY control for a nominal display intensity.

c.ADJUST-FOCUS, R398 (located on the 212 side

panel) for a well-defined dot.

4. Adjust Trace Rotation

a.Set the SEC/DIV switch to 1 m.
b.CHECK-Free-running sweep is parallel with a

horizontal graticule line.

c.ADJUST-Trace Rotation, R141 (see Fig. 4-2) s o
the trace is parallel with the center horizontal graticule
line.

2. Adjust CRT Grid Bias

a.Connect the DC voltmeter between pin 5 and pin

Figure 4-1. Location of power supply test points and CRT

Grid Bias

adjustment.

Figure 4-2. Location of Trace Rotation adjustment.

4-4

VERTICAL SYSTEM ADJUSTMENT

Equipment Requested

TM 9-6625-646-14&P

1.Standard Amplitude Calibrator

2.Square-Wave Generator

3.Low Frequency Constant Amplitude Signal
Generator

4.DC Voltmeter

5.GR-to-BNC Female Adapter

Control Settings

Preset instrument controls to the settings given under

Preliminary Control Settings, except as follows:

INTENSITY Visible Display
INPUT COUPLING DC

(both)

5. Adjust Vertical DC Centering

a.Connect the DC voltmeter between pin 11 of
U105 (positive meter lead to pin 11) and ground (see
Fig. 4-3).

b.Adjust CH 1 Vertical POS control for a 0 volt
meter reading.

c.CHECK-Trace should be within approximately

0.4 division of graticule center.

d.ADJUST-Vertical Centering, R101 (see Fig. 4-3)
to position the trace to the center horizontal graticule line.

e.Disconnect all test equipment.

6.Probe Tip-to-BNC Adapter

7.50-Ohm BNC Termination

8.10X 50-Ohm Attenuator

9.Three-inch Screwdriver

10.Low-Capacitance Screwdriver

6. Adjust CH 1 STEP ATTENuator BALance

a.Rotate the CH 1 VOLTS/D)V switch from 50 m

to 1 m.

b.CHECK-The CRT display for 0.1 division or less
of trace shift between adjacent switch positions when
rotating the VOLTS/DIV switch from 50 m to 1 m.

c.ADJUST-CH 1 STEP ATTEN BAL, R415
(located on the side panel) for minimum trace shift when
rotating the CH 1 VOLTS/DIV switch from 50 m to 1 m.

7. Adjust CH 2 STEP ATTENuator BALance

a.Turn the CH 1 POS control to the OFF detent
and the CH 2 POS control to midrange.

b.Rotate the CH 2 VOLTS/DIV switch from 50 m to
1 m.

c.CHECK-The CRT display for 0.1 division or less
of trace shift between adjacent switch positions when
rotating the VOLTS/DIV switch from 50 m to 1 m.

d.ADJUST-CH 2 STEP ATTEN BAL, R315
(located on the side panel) for minimum trace shift
rotating the CH 2 VOLTS/DIV switch from 50 m to 1 m.

Figure 4-3. Location of Vertical Centering adjustment and

test point.

8. Adjust VERTical GAIN

a.Set the CH 2 VOLTS/DIV switch to 5 m.

b.Connect the CH 2 probe tip to the output of the
Standard Amplitude Calibrator via a probe tip-to-BNC
adapter.

c.Set the Standard Amplitude Calibrator for a 20
millivolts output signal.

d.CHECK-The CRT display for four divisions of
deflection within 0.2 division.

e.ADJUST-VERT GAIN, R470 (located on the side
panel) for exactly four divisions of deflection.

4-5

TM 9-6625-646-14&P

9. Check CH 2 VARiable VOLTS/DIV Range

a.Rotate the CH 2 VOLTS/DIV VAR control fully

clockwise.

b.CHECK-The CRT display for 1.6 divisions or
less of deflection. 1.6 divisions of deflection indicates a
VARiable VOLTS/DIV range of at least 2.5: 1.

c.Set the VARiable VOLTS/D IV control to CAL.

10. Check CH 2 VOLTS/DIV Accuracy

a.CHECK-Using the CH 2 VOLTS/DIV switch and
Standard Amplitude Calibrator settings given in Table 4­3, check that the deflection factor acc uracy for CH 2 is
within 5% at each position.

TABLE 4-3.

Vertical Deflection Accuracy

VOLTS/DIVStandard Vertical Maximum

Switch AmplitudeDeflection Error For

Setting Calibrator in Ù5% Accuracy

Output Divisions

1 m 5 millivolts 5 Ù0.25 division
2 m 10 millivolts 5
5 m 20 millivolts 4 Previously set in

10 m 50 millivolts 5
20 m 0.1 volt 5
50 m 0.2 volt 4

.1 0.5 volt 5
.2 1 volt 5
.5 2 volts 4

1 5 volts 5
2 10 volts 5

5 20 volts 4
10 50 volts 5
20 100 volts 5
50 100 volts 2

Ù0.25 division

step 8.

Ù0.25 division
Ù0.25 division
Ù0.2 division
Ù0.25 division
Ù0.25 division
Ù0.2 division
Ù0.25 division
Ù0.25 division
Ù0.2 division
Ù0.25 division
Ù0.25 division
Ù0.1 division

b.Disconnect the CH 2 probe tip from the Standard

Amplitude Calibrator.

a.Turn CH 2 POS to the OFF detent and the CH 1

POS to midrange.

b.Connect the CH 1 probe tip to the output of the
Standard Amplitude Calibrator via a probe tip-to-BNC
adapter.

c.CHECK-Using the CH 1 VOLTS/DIV switch and
Standard Amplitude Calibrator settings given in Table 4­3, that the deflection factor accuracy of CH 1 at each
position is within 5%.

d.Set the Standard Amplitude Calibrator for a 20
millivolts output signal.

e.Set the CH 1 VOLTS/DIV switch to 5 m.

f.Rotate the CH 1 VARiable VOLTS/DIV control

fully clockwise.

g.CHECK-The CRT display for 1.6 divisions or
less of deflection. 1.6 divisions of deflection indicates a
VARiable VOLTS/DIV range of at least 2.5: 1.

h.Set the VARiable VOLTS/DIV control to CAL.

12. Adjust CH 1 VOLTS/DIV Switch Compen-sation

a.Set the CH 1 VOLTS/DIV switch to 0.1 V.

b.Connect the CH 1 probe tip to the high amplitude
output of the Type 106 Square-Wave generator via a
GR-to-BNC female adapter, a 50-ohm BNC ter mination,
and a probe tip-to-BNC adapter.

c.Adjust the Square-Wave generator for a four­division display of a one kilohertz square wave.

d.Adjust the Triggering controls for a stable
display.

e.CHECK-The CRT display for flat-top waveform
with no more than +0.2 division, -0.1 division, or a total of

0.2 division of aberration.

NOTE
If C307, C308, C309, C407, C408, or
C409 require adjustment, it will be
necessary to remove the instrument
side panel from the Input Board.
Refer to the Disassembly Instructions
for removal procedure.

11. Check CH 1 VOLTS/DIV Accuracy and VARiable
VOLTS/DIV Range

4-6