HP 120B Service manual

Table of Contents

TABLE OF CONTENTS

Section Page Section Page

I

GENERAL INFORMATION

1- 1

.

Introduction

1.4

.

Description

1.14 . Cathode Ray Tube Warranty

1.16

.

Options

11

INSTALLATION 2-1

.

2.1 Incoming Inspection 2-

2.7

.

Power Requirements 2-1

2.10 . Installation 2-2

2.13 . Repackaging for Shipment 2-2

.

3.1

3.3

3.5

IV

PRINCIPLES OF OPERATION

4.1

4.9
4- 10

4.16

4.30

4.34

4.41

Introduction

.

Controls and Indicators

.

General Operating Suggestions

.

Overall Block-Diagram Description . 4-1

Circuit Analysis

.

Vertical Amplifier

.

Sweep Generator

:

Horizontal Amplifier

.

Low-Voltage Power Supply

.
.

High-Voltage Power Supply 4-6

.................

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......

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.......

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....

.........

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1-1
1-

1-1

1-2
1-2

3-1
3-1
3-1

4.1

4-2
4-2
4-3
4-4
4-5

V MAINTENANCE

1

1

5.24

5.27 Low-Voltage Power Supply 5-6

5.33 High-Voltage Power Supply 5-6

5.35

5.42 Horizontal Amplifier 5-10

5.48 Sweep Generator 5-11

5.52 Performance Check 5-11

5.67 Diagrams 5-14

VI

REPLACEABLE PARTS

6.1 Introduction 6-1

6.3 Ordering Information 6-1

Introduction 5-1
Test Equipment 5-1
Troubleshooting 5-1

Repair 5-5

Adjustments 5-6

.

.

.
.
.

.

.
.

.

.

...................

.................

...............

...............

System Troubleshooting 5-1
Sectional Troubleshooting
High-Voltage Power Supply

....................

Replacement of Semiconductors
Servicing Etched Circuit Boards
Crt Replacement

...........

................

Adjustments Following Repair

Vertical Amplifier

..........

...........

...........

..................

............

................

..........

Model 120B

......

.....

....

.
.

. .

.....

....

........

-6-1

5-1

5-2
5-2

5-5
5-5
5-5

5-6

5-9

Model 120B

LlST OF ILLUSTRATIONS

Number Title Page Number Title Page

List of Illustrations and Tables

Model 120B Oscilloscope

Primary-Power Connections
Rack Mounting.

Model
Operation Using Internal Horizontal

Operation Using External Horizontal
Operation Using Balanced Vertical
Vertical Deflection Calibration and

Overall Block Diagram 4­Sweep Generator, Block Diagram 4-2
Sweep Generator Waveforms 4-3
Typical Schmitt Trigger 4-3
Low-Voltage Power Supply, Block

High-Voltage Power Supply, Block

120B Oscilloscope, Front View

Sweep or Single Sweep 3-3

......................

Input .3-4

......................

Input .3-5
Balance Adjustment 3-6

Diagram.
Diagram. .4-6

...............

...................

...................

...........

........

;

.

.

.

...........

.............

............

.....

........

...........

.4-5

LlST OF TABLES

1-1
2­2-2

3-2

Top View, Location of Parts and

1

1

Adjustments 5-3

High-Voltage Power Supply, Location

of Parts. 5-4

Vertical Sensitivity

Source
Parts and Adjustments

Right-Side View, Side Panel Removed,

Location of Parts and Adjustments 5-6
Servicing Etched Circuit Boards.
Vertical Amplifier, Schematic

Diagram 5 - 15
Horizontal Amplifier, Schematic

Diagram 5- 17
Sweep Generator, Schematic Diagram
Low-Voltage Power Supply, Schematic

Diagram 5 - 2
High-Voltage Power Supply, Schematic

Diagram 5- 23

Horizontal Display Switch, Schematic

Diagram. 5-25

..................

....................

(A21 and Trigger

(A201) Switches, Location of

...........

...

.....

.....................

.....................

.....................

.....................

....................

5-5

5-7

.

.

5-19

1

Number Title Page

1-1.

Specifications 1-0
Recommended Test Equipment

System Troubleshooting. 5-4
Adjustments Following Tube,

Transistor, and Diode Replacement.
Low-Voltage Power Supply Voltages
Horizontal Sweep-Time Adjustment.
Horizontal Sweep Time 5-14
Reference Designation Index
Replaceable Parts 6- 14
Code List of Manufacturers

..................

.......

...........

..

...
...

............

........

...............

.........

5-

1

5-8
5-9
5-12

6-

2

6-17

Section I

1-

Table

Model 120B

1

Table

1- 1.

Specifications

SWEEP

Sweep Range:

One

p3ec/cm to

calibrated sweeps accurate to within

1,2,5,10.. . sequence, from 5 psec/cm to 200
millisec/cm. Vernier control permits contin­uous adjustment of sweep time between calibra­ted steps, and extends the 200
least 0.5 sec/cm.

Sweep Expand:

X5 sweep expansion may be used on all ranges
and expands fastest sweep to
panded sweep accuracy

Automatic Synchronization:

Internal: from signals 50 cps to 450 kc with
approximately 0.5-cm or more vertical deflec­tion; and from line voltage.

External: from signal 50 cps to 450 kc, 1.5
peak-to-peak.

Trigger Point:

Zero-crossing negative slope of external sync

signals; or zero-crossing positive or negative
slope of vertical deflection signals. Front-panel
control overrides automatic and permits the
trigger point to be set between
Turning control fully counterclockwise restores
automatic operation.

at

least 0.5 sec/cm.

millisec/cm to at

1

is

*lo%.

psec/cm. Ex-

-7 to +7 volts.

Fifteen

*5%, in a

v

VERTICAL AMPLIFIER

Bandwidth: ating potential. Face plate eliminates glare and

DC coupled: dc to 450 kc. AC coupled: 2 cps reduces hazard of implosion. P2, P7, and
to 450 kc. Bandwidth
less of sensitivity setting.

Sensitivity:

10 millivolts/cm to 100 volts/cm. Four cali- divisions. Eliminates parallax error.
brated steps with attenuator accuracy of
10 mv/cm, 100 mv/cm, 1 v/cm, and 10 v/cm.

Vernier permits continuous adjustment of
tivity between steps, and extends 10
to at least 100

Internal Calibrator: 16-3/4

Calibrating signal automatically connected to deep, overall; hardware furnished for quick con­vertical amplifier for standardizing of gain, ac­curacy

Input Impedance

1

Balanced Input:

On 10 mv/cm range only; input impedance
megohms shunted by approximately 25 pf.

Common-Mode Rejection: 06. Rear terminals in parallel with front.

Rejection at least 40 db. Common mode signal 10. Provision for single sweep operation.
must not exceed

+2%.

megohm, shunted by approximately 50 pf.

v/cm.

:

is

at least 450 kc regard-

+3 volts peak.

*3%,

sensi-

v/cm step

is

2

Phase Shift:

Vertical and horizontal amplifiers have same
phase characteristics within
verniers are in CAL.

+ZO

to 100 kc when

HORIZONTAL AMPLIFIER

Bandwidth:

DC coupled: dc to 300 kc. AC coupled: 2 cps
to 300 kc. Bandwidth
less of attenuator setting.

Sensitivity:

0.1 volt/cm to 100 volts/cm. Three calibrated

steps, accurate within
and 10 v/cm. Vernier permits continuous ad­justment of sensitivity between steps and
tends 10

Input Impedance

1

megohm nominal, shunted by approximately

100 pf.

Phase Shift:

Horizontal and vertical amplifiers have same
phase characteristics within
verniers are in CAL.

v/cm step to at least 100 v/cm.

:

is

at

least 300 kc regard-

&5%,

0.1 v/cm, 1 v/cm,

k2O to 100 kc when

GENERAL

Cathode Ray Tube:

P31 phosphor, mono-accelerator with internal

graticule normally supplied; 2700-volt acceler-

phosphors also available.

Internal Graticule:

10 cm x 10 cm marked in cm squares. Major

horizontal and vertical axes have 2-mm

Intensity Modulation:

Terminals on front panel. Plus 20 volt pulse

required to blank trace of normal intensity.

Dimensions:

in.

wide, 7-1/2 in. high, 18-3/8

version to 7 in. x 19 in. rack mount.

Weight:

Net: 32 lbs; shipping 45 lbs.

Power:

115 or 230 volts

mately 95 watts.

Options

:

05. External graticule crt with P31 phosphor.

13. Special front panel for rack mounting only.

*lo%,

50 to 1000 cps, approlci-

ex-

PI1

sub-

in.

Model 120B

Paragraphs

Section

1-1

to 1-8

I

SECTION

GENERAL INFORMATION

1-1. INTRODUCTION.

1-2. This manual provides complete instructions on

the installation, operation, theory of operation, and

maintenance of the Hewlett-Packard Model 120B Os-

cilloscope.

1-3. The Hewlett-Packard Company uses a

section, eight-digit serial number (e. g. 000-00000).

If

the serial prefix (first three digits) on your instru-

ment does not agree with the prefix shown on the title

page of this manual, refer to either the separate

I,

change sheet included or Appendix
changes required to adapt this manual
prefixes. The separate change sheet also contains
corrections required for all known errata (errors).
Contact your Hewlett-Packard

if

additionalinformation or clarification is required.

Sales/Service Office

which contain

to

1-4. DESCRIPTION.

1-5. The Model 120B
scope whose bandwidth extends from dc to 450 kc. It
combines the precision characteristics of calibrated

is

a general-purpose oscillo-

two-

the listed

I

horizontal sweeps, calibrated vertical sensitivity,

a

crt that eliminates parallax error; in addition,

and
its construction provides easy circuit accessibility
and quick convertibility from a rack-mounting to a
bench-model configuration. Specifications are listed
in table

1-6. The internal graticule of the Model 120B
the same plane as the phosphor and crt trace; conse­quently, crt parallax error

quicker, and more accurate measurements.

1-7. The Model 120B can be used with either internal

or external sweeps, which can be either internally or
externally synchronized. Because of
tivity and balanced input, the Model 120B can be used
to view complex waveforms and monitor transducer
outputs.

1-8. Computations are avoided and possibilities of

error are reduced by direct-reading calibrated sweeps.

A

between the ranges

1-1.

is

in

is

avoided, allowing easier,

its

high sensi-

single control selects 1 of 15 calibrated sweeps

microseconds/cm and 200

of 5

Figure

1-

1.

Model 120B Oscilloscope

1-1

Section I

Paragraphs 1

-

9 to 1 - 18

Model 120B

milliseconds/cm or determines the calibrated sensi­tivity of the horizontal amplifier. Continuous control

of sweep time and horizontal sensitivity between cali-

brated steps is provided

vernier control extends the 200

sweep time to at least 0.5 seconds/cm, and reduces
the horizontal amplifier sensitivity to at least 100
volts/cm.

1-9. Accurate direct-reading sweeps are obtained
from a feedback type (Miller) integrator, which en-

sures high linearity and stability of the horizontal
sweep. This type of sweep generator is reliable and
relatively independent of vacuum-tube characteristics.

1-

10. Observation and analysis of transients are sim­plifiedby the expanded-sweep control. This X5 sweep
expander may be used on all sweep time settings, and
expands the fastest sweep time to

1-

11.

An automatic trigger capability facilitates es­tablishinga base line on the crt when a synchronizing
signal is not present. The automatic baseline pro­vision can be easily locked-out and an adjustable trig­ger level established.

1-

12. Accurate voltage measurements of waveforms
are quickly made with the Model
calibrator that
mits rapid verification and standardization of vertical
amplifier sensitivity.

1-13. Phase-shift measurements can be made ac­curately over a wide range of input frequencies. Rel­ative phase shift between the vertical and horizontal
amplifiers is less than 2 degrees up to 100 kc.

is

accurate to within *2 percent per-

by

a vernier control; the

milliseconds/cm

1

microsecond/cm.

120B. A built-in

1-14. CATHODE RAY TUBE WARRANTY.

1-15. The cathode ray tube supplied with the Model

120B and replacement crt's purchased from Hewlett­Packard Company are guaranteed against electrical
failurefor one year from the date of sale by Hewlett­Packard. The Cathode Ray Tube Warranty and Claim
sheet is included at the rear of this manual.

1-19. OPTION 06.

connectors in parallel with the front panel input con­nectors.
VERTICAL input terminals on the front panel, and
one connector is
TAL input terminals as shown in figures 5-6 and
Mating connectors and cable clamps are also supplied.
The additional circuitry changes the vertical input
capacitance to approximately
input capacitance to approximately 135 pf.

1-20. OPTION 10.

single sweep operation.
contained in figure 3-2 and a schematic for the added
circuit is shown in figure 5-8.

1-21. OPTION 13. This option provides a plain

7 x 9 x 3/16 inch front panel for rack mounting only.
The panel is suitablefor installing special handles to
match existing equipment in system or console
configuration.

1-22. AMBER FILTER.
supplied with oscilloscopes having an internal graticule
crt with
for improved visual observation of displays such as

single-shot phenomena or very low frequency applica-

tions.

characteristics desired for visualobservations of this

type display.

a. Remove front panel crt bezel.

b. Set filter into bezel, aligning larger rectangular
slots in the edge of filter with metal guide posts of the
bezel casting.

c. Remove oscilloscope top cover for access to

rear of crt.

d. Carefully move crt towardrear of instrument

enough to provide clearance for thickness of installed

filter (about 1/8 inch).

One connector is wired in parallel with the

P7 phosphor.

The filter will improve the long persistency

To install the filter proceed as follows:

This option provides rear panel

wiredin parallel with the HORIZON-

5-

75pf, and the horizontal

Thisoptionprovides circuitry for

Operation procedures are

A special amber filter is

This filter may be installed

7.

1-16. OPTIONS.

1-

17. The Model 120B is available with four options,

as

listed in table
are listedunder MISCELLANEOUS at the end of table
6-1.

1-18. OPTION 05. This optionprovides a crt without

internal graticule.
able illumination

Refer to figure 5- 9 for

CRT's without internal graticule are available with
types P7,
plied with each crt; amber for
type, and green for P31 type.

1-

1.

Replaceable parts for alloptions

An

external graticule with adjust-

is

installed over the face of the crt.

a

schematic of the added circuit.

P11, andP3l phosphor. Afilter

P7 type, blue for PI1

is

also sup-

e. Loosen clamp at socket of crt.

f.

Replace bezel with filter and tighten bezel

screws.

g. Slide crt forward until light mask on front of crt

just lightly touches filter.

h. Tighten clamp just enough to keep crt from turn-

ing.

Do not over-tighten the clamp or tube damage

may result.

i. Check alignment of trace with graticule accord-

ing to theprocedure given in Section V of this manual.

Model 120B

Paragraphs 2-1 to 2-9

Section

I1

SECTION

INSTALLATION

2-1.

INCOMING INSPECTION.

2-2. MECHANICAL INSPECTION. Unpack and in­spect the Model 120B in the presence of the carrier.
Be careful when unpacking the instrument, for all
electron tubes including the cathode ray tube remain
installed during shipment. Save all packing materials
until inspection

be required for reshipment in the event shipping dam-

is

age

age in shipment such as scratched panel, broken
knobs, etc.
check it operationally (see paragraph

claim with the carrier. Refer to the Hewlett-Packard
Warranty sheet at the front of this manual.

2-5. PERFORMANCE CHECK. Paragraph 5-52 con­tains performance check procedures for verifying

operation within listed specifications. The perform­ance check is recommended for inclusion in receiv­ing quality-control inspection. The following proce-

dure

operation.
2-6. INITIAL TURN ON. Energize the 120B as

follows:
power cable.

LISECONDS/CM position.
POSITION controls.

If

adjust position controls as necessary.

adjust HORIZONTAL POSITION to place left end of

sweep on left-end graticule line.

discovered.

2-3. Inspect the instrument for signs of possible dam-

If

2-4.

a. Turn INTENSITY control to OFF and plug in

b.

c. Set HORIZONTAL DISPLAY switch to 0.5
d. Center HORIZONTAL POSITION and VERTICAL
e. Turn 120B on and allow

f

g. Rotate INTENSITY clockwise until trace appears.

h. Adjust FOCUS for thin, -well-defined trace, and

there are any indications of damage, file a

is

offered, however, as a means to check basic

Set SWEEP MAGNIFIER switch to X1 position.

.

Set TRIGGER LEVEL to AUTO.

crt remains blank, press BEAM FINDER and re-

is

complete. These materials may

If

possible, energize the equipment and

2-

5).

two

minutes warmup.

MIL-

II

230

VOLTS AC

115

VOLTS AC

:41

Figure 2-

I

2

3

4

1L

230 VOLT CONNECTION

I

2

3

4

115

VOLT CONNECTION

1.

Primary-Power Connections

T302

T 302

LO-S-529

2-7.

2-8. The Model 120B requires a power source of 115
or 230 volts
can deliver approximately 95 watts. The oscilloscope

is

with a 115-volts power source. To convert the in-

strument for use with a 230-volt source, change the
dual primary windings of transformer T302 from a
parallel combination to a series combination. Figure

2-1 illustrates the connection for 115- and 230-volt
operation. At the time of the change, replace the

1.5-ampere slow-blow line fuse with 1-ampere

blow fuse.

POWER REQUIREMENTS.

?lo%,

single phase, 50 to 1000 cps, which

normally shipped from the factory wired for use

slow-

2-9.

For the protection of operating personnel, the

National Electrical Manufacturers' Assn (NEMA)

recommends that the instrument panel and cabinet
be grounded. This instrument is equipped with a
three-conductor power cable which, when plugged into

an appropriate receptacle, grounds the instrument.

The offset pin on the power cable three-prong con­nector is the ground pin. To preserve the protection
feature when operating the instrument from a

contact outlet, use a three-prong to two-prong adap­ter and connect the green pigtail on the adapter to
ground.

two-

Section

II

Paragraphs 2-10 to 2-14

INSTRUCTIONS
I. REMOVE TILT STAND, FEET, AND

TRIM STRIP.

2.ATTACH FILLER STRIP AND FLANGES
KEEPING LARGENOTCHONFLANGES
TO INSTRUMENT BOTTOM.

Model 120B

FILLER STRIP

RACK MOUNTING

Figure 2-2. Rack Mounting

2-10. INSTALLATION.

2-11. MODULAR CABINET. The Model l2OB Oscil-

is

loscope
ment with the tilt stand, feet andplastic trim

shipped fromthe factory as a bench instru-

inplace.

The top and bottom cabinet covers may be removed,
giving complete accessibility to all components and
adjustments. When used on the bench, other instru-

be

ments may

stacked on the louver-free top surface;
however, sufficient space should be allowed around
the cabinet for adequate circulation of air.

2-12.

RACK

MOUNTING. Prepare the cabinet for
rack mounting as illustrated in figure 2-2. The trim
strip and rack-mounting flanges are in the shipping
container with the instrument. After preparation, lift
instrument into place and secure mounting flanges to
rack with appropriate screws. Allow adequate venti­lation for the instrument in the rack.

2-13. REPACKAGING FOR SHIPMENT.

2-14. The following

packagingan instrument for shipment; however,
have any questions, contact your authorized

Packard sales representative.

list

is

a general guide for re-

Hewlett-

if

you

LO-M-489

a.

If

possible, use original container designed for

the instrument.

b. Wrap instrument

in

heavy paper or plastic before

placing it in shipping container.

c. Use sufficient quantities of packing material
around all sides of the instrument and protect panel
with cardboard strips.

d. Use heavy cardboard carton or wooden box to
house the instrument and use heavy tape or metal
bands to seal the container.

e. Mark packing box with "Fragile", "Delicate In­strument", etc.

Note

If

the instrument

is

to be shipped to

Hewlett-Packard Company for ser-

vice or repair, attach to the instru-

ment atag identifyingthe owner, the

instrument's complete serial num­ber, and the service or repair to be
accomplished; in addition, notify
Hewlett-Packard Company or a rep­resentative before shipping the in­strument. In any correspondence,
reference the instrument by model
number and complete serial number.

Model 120B

Section

Paragraphs 3- 1 to 3-16

III

SECTION

OPERATION

3-2. This section contains operating instructions for
the Model 120B Oscilloscope. Included are descrip­tions of the Model 120B controls and indicators, and
operation of the Model
oscilloscope.

3-3.

CONTROLS AND INDICATORS.

Figure 3-1 illustrates the controls and indica-

3-4.
tors along with a short description of the particular
function of each.

3-5, GENERAL OPERATING

SUGGESTIONS.

3-6. The following paragraphs, 3-7 through 3-16,
provide suggestions for expediting and simplifying
operation of the Model

3-7. SYNCHRONIZING THE SWEEP. The horizontal
sweep can be synchronized with the vertical input

signal (INT positions of TRIGGER SOURCE switch),
the ac line frequency (LINE position), or an external
sync signal (EXT position).

3-8. When the TRIGGER LEVEL control

position, a sweep appears on the crt without applica­tion of any type of synchronizing signal; however,
when a synchronizing signal above approximately 50
cps is applied, the sweep automatically synchronizes
with this signal and the sweep
point where the signal crosses the zero axis (average
dc level of synchronization signal).
ing signal below approximately 50 cps
the TRIGGER LEVEL control should be out of AUTO
position.

3-9. Rotating the TRIGGER LEVEL control in a
clockwise direction permits the trigger point to be
set between
going portion of a vertical input signal, depending on
whether the TRIGGER SOURCE switch is in
INT- position, respectively. When the TRIGGER
SOURCE switch
GER LEVEL control in a clockwise direction permits
the trigger point to be set between
negative-going portion of the synchronizing signal.

3-10. The particular type of synchronization best
suited depends on the type of measurement being made
and the type of crt display desired.

3-11.
switch in AC position) removes any dc level present
in the vertical or horizontal input signals. This pre­vents excessive dc levels from deflecting the crt trace
off the face of the crt, often to the point where the
POSITION controls cannot bring the crt trace within
view.

rt2 cm along the positive or negative-

is

in EXT position, rotating the TRIG-

AC/DC COUPLING. Ac coupling (AC - DC

120B as a general-purpose

120B.

is

in AUTO

is

triggered at the
If

a synchroniz-

is

being used,

INT+ or

rt7 volts along the

Ill

CAUTION

When using ac coupling, do not
ceed a dc level input of 600 volts.

3-12. When pulse or square waves having a
cy less than 200 cps are being measured, dc coupling

is recommended (AC-DC switch-in DC position).
3-13. BEAM FINDER OPERATION. The crt trace

may frequently be deflected off the crt face by exces­sive dc input levels or by misadjustment of the verti­cal POSITION and horizontal POSITION controls.

The BEAM FINDER pushbutton is extremely useful
under these conditions. When the BEAM FINDER
depressed, the beam is confined to the face of the

crt, brightened, and defocused to prevent burning of
the crt phosphor.

POSITION controls when the BEAM FINDER
pressed, the trace will remain on the crt face when
the BEAM FINDER

3-14. VERTICAL SENSITIVITY SELECTION. When
the vertical VERNIER control

VERTICAL SENSITIVITY switch provides attenuation

of the vertical input signal in four calibrated steps,

10

mv/cm, 100 mv/cm, 1 v/cm, and 10 v/cm.

tating the vertical VERNIER control in a counter-

clockwise direction permits continuous adjustment of

sensitivity between steps, and extends 10

at

least 100 v/cm. When the VERTICAL SENSITI-

to
VITY switch

is automatically connected to the vertical amplifier.

3

-

15. COMMON-MODE REJECTION. Balanced in­put to the vertical amplifier
the ground jumper across two of the vertical input
terminals and applying a balanced signal input. Bal­anced input
sired to simultaneously amplify the out-of-phase (dif­ferential) signal and attenuate the in-phase (common
mode) signals, such as hum, noise, etc.

3-16. A change in the relative position of the Model

120B Oscilloscope with respect to the earth's mag­netic field could result in the trace becoming mis­aligned. To re-align the trace with the graticule,
adjust SCALE, screwdriver adjustment ,on the front
panel (Figure 3-1).

Figures 3-2 through 3-5 assume
that the FOCUS, POSITION, and IN­TENSITY controls are preset by the
operator for the desired display.

If

in doubt as to the exact function
of a switch listed in figures 3-2
through 3-5, refer to figure 3-1
for a functional description.

If

the crt trace

is

released.

is

in CAL position, a calibrating signal

is

useful in applications where it

Notes

is

is

in CAL position, the

is

obtained by removing

ex-

frequen-

is

centered with the

is

de-

Ro-

v/cm step

is

de-

Section

III

Figure 3-

Model 120B

1

7

-4

0.c

HEWLC

20 19

1.

FOCUS: Controls crt focus.

18

I7 16 15

11.

14

13 12

11

10 9 8

MP-M-

Vertical POSITION: Controls verticalposi­tion of crt display.

2. Horizontal VERNIER: Adjusts sensitivity
between ranges; in CAL position, deflec-

tion

as

indicated

by

selected

VOLTS/CM

position of HORIZONTAL DISPLAY switch.

3. HORIZONTAL DISPLAY: 15 positions se- 13. SWEEP MAGNIFIER:

3

lect sweep speed,

positions select hori-

zontal deflection sensitivity.

4. TRIGGER LEVEL: Determines level of
trigger point on sync signal.

12. BAL: Adjust for no vertical shift with ro­tation of vertical VERNIER.

In

Xl position sweep
time selected by HORIZONTAL DISPLAY.
In

X5position sweep speed

is

5

times faster.

14. EXT. SYNC OR HORIZ: External sync or
horizontal amplifier input.

5. TRIGGER SOURCE: Four positions select
sweep synchronization. 15. Horizontal AC-DC: AC position input

itively coupled into horizontal amplifier.

6.

Vertical VERNIER: Adjusts sensitivity be-

DC position input directly coupled into hor-

tween ranges; in CAL position, deflection izontal amplifier.
as selected by VERTICAL SENSITMTY
switch. 16. Z AXIS: Input for crt intensity modulation

signal.

7. VERTICAL SENSITIVITY: Four positions
select deflection sensitivity. CAL position 17. Horizontal POSITION: Controls horizontal

displays internal calibrator signal.

position of crt display.

85

capac-

8.

CAL: Adjusts calibration of vertical input.

18.

BEAM FINDER: Returns beam to crt face
regardless of horizontal and vertical POSI-

9.

Vertical input terminals. TION settings.

10. Vertical AC-DC: AC position input capaci- 19. INTENSITY
tively coupled into vertical amplifier. DC

power and controls crt intensity.

&

POWER: Applies ac line

position input directly coupled into vertical
amplifier. 20. SCALE: Aligns trace with graticule.

Figure 3-1.

Model 120B Oscilloscope, Front View

01260-1

Model

120B

Section

Figure

Ill

3-2

INTERNAL HORIZONTAL SWEEP:

1.

Set vertical AC-DC to desired type of input A. Set SWEEP switch to normal (N), TRIGGER
coupling.

2.

Set VERTICAL SENSITIVITY to desired vertical
sensitivity.

3.

Set vertical VERNIER to CAL for calibrated Minimum trigger sensitivity

SINGLE SWEEP (OPTION

SOURCE switch to EXT, and remove any external
trigger source.

B.

Adjust TRIGGER LEVEL control fully clockwise.

is

10):

obtained with the

sensitivity. control in this position.

4.

Set HORIZONTAL DISPLAY to desired horizontal

C. To increase trigger sensitivity, rotate TRIGGER
sweep time. Set VERNIER to CAL for calibrated LEVEL control counterclockwise. Maximum
sweep time.

X1

5. Set SWEEP MAGNIFIER to

6.

Set TRIGGERSOURCE to desired type of horizon­tal sweep synchronization.

or X5, as desired.

If

external sync

selected, connect sync signal to EXT. SYNC.

7.

Apply vertical input signal to vertical input

terminals.

8.

Adjust TRIGGER LEVEL for desired synchroni-

zation.

I

Figure

3-2.

Operation Using Internal'Horizontal Sweep or Single Sweep

is

sensitivity will be obtained just prior to the point

where the oscilloscope sweeps intermittently.

D. Set SWEEP switch to single (S). The instrument

is

now in the "armed" state and will sweep once

when triggered.

E. To rearm the sweep circuit, set SWEEP switch

from S to N and then back to S. External triggering
should not be applied during this operation to
vent the single sweep from occurring immediately

is

when the switch

returned to the S position.

pre-

Section

III

Figure 3-3

SWEEP

MAGNIFIER

Model

120B

1.

Set vertical AC-DC to desired type of input

6.

Apply external horizontal sweep to hori-

coupling. zontal input terminals.

2.

Set VERTICAL SENSITIVITY to desired ver-

7.

Apply vertical input signal to vertical input

tical sensitivity. terminals.

Set vertical VERNIER to

3.

CALfor calibrated

sensitivity. Note

4.

Set HORIZONTAL DISPLAY to desired
VOLTS/CM. Set VERNIER to CAL for cal­ibrated sensitivity.

5.

Set horizontal AC-DC to desired type of

Relative phase shift of hori­zontal and vertical amplifiers

is

the same

+2"

to

100

kc only

when both VERNIER controls

coupling. are set to CAL.

Figure 3-3. Operation Using External Horizontal Input

3

-4

Model 120B

SWEEP

MAGNIFIER

Section

111

Figure 3-4

Remove grounding strap from vertical in-

Set vertical AC-DC to desired type of input

1.

7.

coupling. put terminals.

2. Set VERTICAL
VOLTS/CM. (Input not balanced in any terminals;
other position of VERTICAL SENSITMTY nect

switch.

Set vertical VERNIER to CAL for calibrated

3.

)

sensitivity.
Set HORIZONTAL DISPLAY to desired hor- The common-mode input sig-

4.

izontal sweep speed.

SENSITIVITY to 10 MILLI-

8.

Connect vertical signal to vertical input

if

ac coupling

0. 1-uf 600-volt capacitor in series

with center vertical input terminal.

Note

nal voltage, either positive or
negative, must not exceed 3

5. Set SWEEP MAGNIFIER to
desired.

6. Set TRIGGER SOURCE to desired type of

X1 or X5, as volts minus the peak amplitude

of the differential input signal.

9.

Adjust TRIGGER LEVEL for desired syn-

horizontal sweep synchronization. chronization.

is

desired, con-

LO-U-.92

Figure 3-4. Operation Using Balanced Vertical Input

3-5

Section

Figure 3-5

III

Model 120B

SWEEP MAGNIFIER

CALIBRATION ADJUSTMENTS:

1.

Set vertical VERNIER to CAL.

2. Set VERTICAL SENSITIVITY to CAL.

Adjust CAL for exactly

3.

flection.

6

cm of vertical de-

While rotating vertical VERNIER back and

7.

forth, adjust BAL for no shift of spot.

BALANCE ADJUSTMENTS:

4.

Set VERTICAL SENSITIVITY to 10
VOLTS/CM.

Set vertical AC-DC to DC.

5.

6.

Short vertical input terminals.

LD-Y-490

MILLI-

Figure 3

-

5.

Vertical Deflection Calibration and Balance Adjustment

01260-1

Model 120B

Section

IV

Paragraphs 4-1 to 4-8

SECTION

PRINCIPLES OF OPERATION

4-1.

OVERALL BLOCK-DIAGRAM

DESCRIPTION.

is

4-2. The oscilloscope
functional circuit groups:
sweep generator, the horizontal amplifier, the low­voltage power supply, and the high-voltage power

ply (see figure 4-1).

4-3. The vertical input signal is applied to the ver­tical amplifier through a frequency -compensated
tenuator. The vertical amplifier converts the vertical
input to two 180-degree-out-of -phase signals and ap­plies the amplified signals to the crt as the vertical
deflection; in addition, the vertical amplifier applies
the signals to the TRIGGER SOURCE switch, when
they are used

as

the INT+ and INT- sync signals.

4-41 The horizontal or sync input signal
the HORIZONTAL DISPLAY switch. Depending on the
setting of this switch, the signal is applied to either
the TRIGGER SOURCE switch (to be used as the ex­ternal sync signal) or to the horizontal amplifier (to
be used as the external horizontal input signal).

In

4-5.

addition tothe internal and external sync sig-

nals, the TRIGGER SOURCE switch receives 6.3 volts

ac from the low-voltage power supply; this provides

a

sync-signal repetition rate equal to the line-

for
voltage frequency.

comprised of five major

the vertical

amplifier,

sup-

is

applied to

the

at-

IV

4-6. The sync signal selected by the TRIGGER
SOURCE switch is-applied to the sweep generator,

wherein the sync signal initiates the horizontal sweep

signal and the unblanking gate. The sweep generator
applies the sweep signal to the horizontal amplifier,
and the resultant amplified sweep
crt as the horizontal deflection signal. The unblank-

is

ing gate

If

an external horizontal sweep is being applied

applied to the high-voltage power supply.

place of the sweep from the sweep generator, the ex-

ternal sweep

is

amplified by the horizontal amplifier

and applied to the crt.

4-7. The low-voltage power supply receives
volts, single-phase power from the line andgenerates

the following output voltages: 6.3 volts ac, a regu-

lated +19 volts dc, +99 volts dc,
volts dc,

+300 volts dc, and an unregulated +420 volts
dc. These voltages are distributed, as required, to
the high-voltage power supply, the vertical amplifier,
the horizontal amplifier, and the sweep generator.

4-8. The high-voltage power supply generates the

high voltages for the

crt. The unblanking gate and

Z-axis signals applied to the high-voltage power .sup­ply effectively alter the value of the power-supply
voltages to allow unblanking and modulation of the crt

intensity.

is

applied to the

in

115/230-

+I00 volts dc, -150

VERTICAL DEFLECTION

VERTICAL

GENERATOR HORIZONTAL SWEEP

(

I OF 3 SECTIONS

115/230 VOLTS
60 CPS 6 3 VOLTS AC
l PHASE

)

LOW

POWER

SUPPLY D-C VOLTAGE AND SWEEP

Figure 4-1. Overall Block Diagram

-

-+

HIGH VOLTAGE

POWER FOCUS VOLTAGE

SUPPLY

INTENSITY VOLTAGE

\

*

>TO CRT

b

+

1

CIRCUIT

80-"-266

4-1

Section IV
Paragraphs 4-9 to 4-15

Model

120B

4-9.

CIRCUIT ANALYSIS.

4-10.

VERTICAL AMPLIFIER.

4-11. For ac coupling, capacitor C1

is

placed in
series with the signal path by means of the AC-DC
switch. (See figure 5-6.
applied to VERTICAL SENSITIVITY switch
the switch

is

in the CAL position, the input of the am-

)

The input signal

is

then

S2. When

plifier is directly connected to the output of the cali­brator (V4, V5, and associated circuit parts). When

is

the VERTICAL SENSITIVITY switch

in other posi­tions, precision frequency-adjusted attenuators are
inserted. These attenuators give a ten-to-one atten­uation between adjacent positions. The input signal

is

then applied to the control grid of amplifier VIA.
4-12. Balanced input to differential amplifier V1B

is

obtained by removing the ground jumper across re­sistor

R1 (ground strap on front panel) and applying a
balanced signal input. Balanced input is useful in ap­plications where it

is

desired to simultaneously am­plify the out-of-phase (differential) signal and atten­uate the in-phase (common mode) signals, such as
hum, noise, etc. This rejection

is

an inherent prop­erty of differential amplifiers. The common-mode
signals are attenuated by 40 db
differential input

is

amplified.

(100:1), whereas any

4-13. The vertical amplifier consists of three sets
of balanced differential amplifiers

(Vl, V2, and V3)

in cascade. The three stages are neutralized by

plate-to-grid cross neutralization. The first stage,

V1, has balance and gain adjustments. The balance
adjustment (BAL)

is

potentiometer R16 in the cathode

circuit, which adjusts the current distribution be-

tween the two triodes. Potentiometers
control) and

R20 (CAL) adjust the resistance between

R21 (VERNIER

the plates and therefore determine the gain of the am­plifier. The VERTICAL VERNIER control provides

a

ten-to-one variation in gain between ranges of the
VERTICAL SENSITIVITY switch. The second differ­ential amplifier,

V2, has potentiometer R32 (vertical

POSITION control) between its cathodes. This po­tentiometer controls the current distribution between
the two triodes and thus determines the vertical posi­tion of the crt display. The third differential
fler, V3,

is

the output stage. Synchronization signals

ampli-

are taken from the plates of V3 for application to the
TRIGGER SOURCE switch. Since the horizontal
sweep circuits trigger only on the negative slope of
the signal, provision is made to take the proper syn­chronizing signal from either plate of V3.

4-14. One section of the BEAM FINDER switch is in

the cathode circuit of V3.

When pressed, the switch

increases the common cathode resistance and so re-

duces the gain of the stage that no amount of unbalance
ahead of V3 can deflect the sweep off the crt.

4-15. The calibrator circuit consists of neon lamps
V4,

V5, and associated circuit parts. When VERT-

ICAL SENSITIVITY switch

S2 is placed in the CAL

position, V4 ionizes and capacitor C14 begins charg-

ing. As the voltage across capacitor C14 rises, the

voltage at the junction of V4 and R52 rises propor­tionally. When the voltage at this junction reaches
the firing potential of
ducting potential of V5

V5, V5 ionizes. Since the con-

is

less the firing potential, the
voltage at the junction of V4 and V5 drops, and V4 de­ionizes. C14 discharges through

R53, and the poten-

tial across V4 increases. When the potential across

FROM

ITRIGGER

SOURCE

SW

SYNC

I

-+

9

[TRIGGER LEVEL

I

I

I

TRIGGER

GENERATOR

v201

-

Figure

I

-

NETWORK

4-2.

TRIGGER

v202

STOP

A

HOLD-

OFF

CATHODE

FOLLOWER

V203B

Sweep Generator,

i

Block

SWITCH DIODE

CLAMP

V203A

A

-

Diagram

GATE-OUT

CATHODE

FOLLOWER

V204

-v

n

'

I V205A

I

I

I

I

:--

ISWEEP

MAGNIFIER]

*

-

UNBLANKING
GATE TO
HIGH-VOLTAGE
POWER SUPPLY

SAWTOOTH

*

INTEGRATOR

+

SAWTOOTH

CATHODE

FOLLOWER

V205B

-

A

TO
HORIZONTAL

AMPLIFIER

83-U-267

01260-1

Model 120B

Section

IV

Paragraphs 4-16 to 4-22

GRlD OF

V201A

PLATE OF
V201B

JUNCTION

OF C207

C208

AND

PLATE OF
V202B

GRID OF
V203B
(SEE NOTE)

GRlD

OF

V202A

-1

'

-

I

I

I

I

I

I

I

I

I

I

I

I

I

I
I

I

I

I

1

I

I

I

I

I

I

I

I

I

LENGTH

OF

SAWTOOTH

TIME CONSTANT

ON RC
SELECTEDBY

HORIZONTAL

SWITCH

DISPLAY^

DEPENDS

LD-S-

530

the negative-going output

is

applied to switch diode

CR201.

4-19. Switch diode CR201 normally clamps the input
to sawtooth integrator
age, preventing sawtooth integrator
erating a sawtooth waveform. When the
going step signal from the start-stop trigger
to the switch diode, however, the diode

V205A to a low negative volt-

V205A from gen-

negative-

is

applied

is

reverse
biased and allows the sawtooth integrator to generate
a sawtooth waveform.

4-20. The sawtooth output of

V205B

applied to the horizontal amplifier to serve

is

simultaneously

as

the

horizontal sweep signal and the hold-off cathode fol-

V203B. The output of the hold-off cathode fol-

lower
lower

is

applied to the input of the start-stop trigger

terininate the sweep. The values of R and C selected

to
by the HORIZONTAL DISPLAY switch determines the

slope of the
Clamp V204 ensures that the sawtooth always

sweepand therefore the time of the sweep.

starts

at the same level. Figure 4-3 shows the relative
timing of the sweep generator waveforms.

4-21. TRIGGER GENERATOR V201. (See figure

5-8.)

SOURCE switch
resistor

is

control
form of bi-stable multivibrator, and

The sync signal selected by the TRIGGER

is

applied through capacitor C202 and

R201 to the input control grid of V201, which

a Schmitt trigger circuit when the TRIGGER LEVEL

is

not in AUTO. The Schmitt trigger

is

used to obtain

is

pulses with rapid rise and fall times.
4-22. Figure 4-4 illustrates a simplified Schmitt

If

trigger and typical input and output waveforms.

is

itially the input voltage (figure 4-4)

+

DC

such that V1

in-

is

a

Figure 4-3. Sweep Generator Waveforms

V4 reaches the firing potential, V4 fires and the volt-

4

b

(w

OUTWT

age at the junction of V4 and V5 drops, deionizing V5.
C14 starts charging again, and the cycle repeats. A

is

60-mv square wave

this signal

is

applied through the SENSITIVITY switch

developed across R54, and

I

INPUT

v2

v

to the vertical amplifier.

4-16.

SWEEP GENERATOR.

4-17. BLOCK-DIAGRAM DESCRIPTION. (See figure

4-2.) The sync signal from the TRIGGER SOURCE

is

switch

applied to trigger generator V201. The trig-

-

-

-

-

-

ger generator produces a rectangular wave with a
repetition frequency equal to that of the input sync
signal. This rectangular wave is applied to a differ-

it

entiating network which converts

to positive and
negative spikes that are coincident with the leading
and trailing edges of the rectangular wave. These
spikes are then applied to the input of start-stop trig­ger V202.

4-18. The negative spike switches the start-stop
trigger, which produces two step outputs. The posi-

is

tive-going output

applied through V204 to the high-

-

ob

-

-

a

I

b

LO 5-53!

voltage power supply as the crt unblanking gate, and Figure 4-4. Typical Schmitt Trigger

Section IV

Paragraphs 4-23 to 4-32

Model 120B

cutoff, V2 conducts. As the input voltage becomes
more positive, it eventually reaches a predetermined
level (a) at which the circuit changes state; that

V1 conducts and V2
goes negative, the common cathode potential decreases
and the grid of V2 becomes positive. When the input

reaches a second predetermined level
and the circuit switches back to
output of the circuit
or negative depending upon the slope of the input

signal.

4-23. The input voltage levels at which a Schmitt
trigger circuit switches are called the hysteresis
limits. Note that the circuit (figure 4-4) does not
switch unless the input crosses both limits.

4-24. Trigger generator V201 has some additional

features: the TRIGGER LEVEL control adjusts the
bias on

input trigger must reach to change state; in addition,

when the TRIGGER LEVEL control

limit, switch S202
shunt across resistor R207 and capacitors C205 and
C206, and the trigger generator becomes an astable
multivibrator. This provides triggers to the
start trigger even though no sync is applied to the

trigger generator. When a sync signal above approxi-

mately 50 cps

erator then synchronizes with the sync signal. The

step output of the trigger generator

plate of

4-25. DIFFERENTIATING NETWORK. (See figure
5-8.) The differentiating network
series combination of capacitor

and resistor R210. The r-c time constant of this net­work
the trigger generator output pulses; consequently, the

signal developed across inductor L201 and resistor

R210 consists of short negative and positive spikes
that are coincident with the leading and trailing edges
of the trigger generator output pulses. These spikes
are coupled through capacitor C208 to the control grid
of

4-26. START-STOPTRIGGER
AND SWITCH DIODE CR201. -(See figure 5-8. ) The
start-stop trigger is a Schmitt trigger circuit. A

typical Schmitt trigger

V202 is triggered by a negative spike pulse from the
differentiating network. One output step waveform is
taken from the plate of
plies to switch diode

V203A. The waveform applied to V203A cuts off

V203A, and thus disables the clamping action of this
tube. The waveform applied to switch diode

reverse-biases the diode, and thus it ceases conduc­tion. Another step output

V202A and applied through cathode follower V204 to
the high-voltage power supply; this serves as the crt
unblanking gate.

4-27. SAWTOOTH GENERATOR

TOOTH CATHODE FOLLOWER

V2OlA and thus determines the level which the

V201B andapplied to a differentiating network.

is

extremely small compared with the width of

V202A, one half of the start-stop trigger.

is

cutoff.

is

a voltage step, either positive

is

placed in AUTO. This opens the

is

applied, however, the trigger gen-

is

V202B and simultaneously ap-

CR201 and the grid of clamp

If

the input voltage then

(b),

V2 conducts

its

initial state. The

is

at its extreme

is

taken from the

is

composed of the

C207, inductor L201,

V202, CLAMP V203A,

described in paragraph 4-22.

is

taken from the plate of

V205A AND SAW-

V205B. (See figure

is,

stop-

CR201

5-8.) Sawtooth generator
tegrator which produces a linear sawtooth waveform.
When switch diode
tegrating capacitor charges through the integrating

resistance, producing a negative-going potential at
the control-grid of
the plate of

cathode follower

completing the negative feedback required by this

Miller type integrator.

4-28. The sawtooth signal at the cathode of
also applied to SWEEP MAGNIFIER switch S102.
When ,9102
to the horizontal amplifier has
times greater than that applied when S102
position; hence, the angle of slope is increased five
times and the sweep time
by the HORIZONTAL DISPLAY switch.

4-29. The sawtooth signal at the cathode of
applied to the control grid of V202A. When the slope
of the signalreaches the upper hysteresis limit of the
start-stop trigger, the trigger changes state; hence,
the unblanking gate output of
The switch diode
respectively, halting the charging of the integrating
capacitor and terminating the sawtooth waveform.
The hold-off capacitor in the cathode of
during the rising slope of the signal output of the
off cathode follower but does not immediately dis­charge when the sawtooth input to the hold-off cathode
follower terminates. This prevents the start-stop
trigger from again being triggered by a negative spike
until the sweep circuits have fully recovered. A dif­ferent value of hold-off capacity
setting of the HORIZONTAL DISPLAY switch.

4-30.

4-31. The grid of VlOlA (figure 5-7) receives either
the sweep output from the horizontal sweep circuits
or from an external sweep source, depending on the
setting of the HORIZONTAL DISPLAY switch. When
external sweep is being used (EXT SENSITIVITY posi­tions), any one of three horizontal sweep sensitivities
can be selected:
VOLTS/CM. The AC-DC switch allows selection of
direct coupling, or ac coupling through capacitor
C101.

4-32. The horizontal amplifier consists of two dif­ferential amplifiers
the HORIZONTAL DISPLAY switch
EXT SENSITIVITY positions, the resistance between
the cathodes of amplifier VlOl consists of the hori­zontal VERNIER control
horizontal gain control
R107 is between the cathodes. The horizontal POSI­TION control (potentiometer
of VlOl controls the horizontal position of the crt
trace. The second stage

plate-to-grid cross neutralization. The output of the

horizontal amplifier
and applied directly to the horizontal deflection plates
of the crt.

V205A

is

HORIZONTAL AMPLIFIER.

CR201 ceases conduction, the in-

V205A. The amplified signal at

is

V205B to the integrating capacitor,

in the X5 position, the sawtooth applied

CR20l and clamp V204 again conduct,

.1

VOLTS/CM, 1 VOLTS/CM, or 10

(V101 and V102) in cascade. When

is

V205A is a Miller in-

coupled back through sawtooth

V205B

a

peak amplitude five

is

in the X1

is

one-fifth of that selected

V203B

V203A is terminated.

V203B charges

is

selected for each

is

set to one of the

(R275B) in series with the

(R104); otherwise, resistor

R109) between the plates

(V102)

taken from the plates of V102

is

neutralized by

is

is

hold-

Model 120B

Section

Paragraphs 4-33 to 4-40

IV

+I9 VOLT DC

AC

b

REGULATED

POWER SUPPLY

-

115/230 VOLTS

60

CPS

IPHASE

4-33.

the cathode circuit of

increases the common cathode resistance and so re­duces the gain of the stage that no amount of unbalance

ahead of V102 can deflect the sweep off the crt.

4-34.

4-3 5. BLOCK-DIAGRAM DESCRIPTION. (See figure

4-5.) The
plied through switch S301 to transformer
transformer applies 6.3 volts ac to the vertical am­plifier, horizontal amplifier, sweep generator, and
high-voltage power supply for use as filament voltage;
the transformer also applies appropriate ac voltages
to the following: the

supply; the
power supply; and the -150-volt dc regulated power

supply.

4-36. The regulated power supplies deliver their dc
outputs to the following circuits:
applied

'I9, + loo,

vertical amplifier, the horizontal amplifier, the hor-

izontal sweep circuits, and the high-voltage power

supply; in addition, the -150-volt supply applies
ative

supplies for use as a control voltage.

One section of the BEAM FINDER switch

LOW-VOLTAGE POWER SUPPLY.

to

voltage to the +19-. +99-. +loo-. and +300-volt

S301

--

I

I
I

115/230-volt, single-phase power is ap-

+300-, +loo-, and +99-volt dc regulated

the horizontal and vertical amplifiers; and

+300,

TRANSFORMER

T302

Yigure 4-5. Low-Voltage Power Supply, Block Diagram

V102. When pressed, the switch

+19-volt d-c regulated power

and

-

-

-

b

T302. The

+

19 volts dc is

are

'

to

aneg-

+420,*300,+
AND199 VOLTS

OC REGULATED
POWER SUPPLY

-150-VOLT DC

POWER SUPPLY

is

the

T

100

t

REGULATED

in

tor C325A. The resulting dc voltage
further by tubes

4-38. The circuit functions as follows: when power

is

justed properly) the cathode of V310 becomes fixed at

-65 volts and the grid assumes a slightly more nega­tive value.
change were to occur, tending to lower the supply
voltage, V310 grid potential would tend to change by
half the amount, since the grid
divider between -150 volts and ground. The result

is

raising

bias on

resistance, decreasing the voltage drop across this
element which tends to return the supply voltage
its original value.

4-39.
POWER

operates in almost exactly the same manner as the

-

150-volt supply except that it uses the - 150-volt sup-

ply

CR302, V307, and V308
ulator, and amplifier, respectively. The
+99-volt supply is further regulated by V308B, ref­erenced to the +300-volt supply.

+

19

VOLTS DC

TO AMPLIFIERS
VI,V2 AND VlOl

2)

+99VOLTS DC
+300 VOLTS DC
+I00 VOLTS DC
+420VOLTS DC UNREG

TO AMPLIFIERS,

6.3 VOLTS AC AND HIGH-VOLTAGE

-150 VOLTS DC

V309, V310, and V311.

applied (assuming the - 150-volt supply has been ad-

If

a line voltage surge or load current

increased bias for V310, lowering its current,

its

plate voltage, which, in turn, lowers the

V309. This bias change in V309 lowers its

+300-. +loo- AND +99-VOLT DC REGULATED

as

SUPPLY.

its

voltage

The +300-volt supply (figure 5-9)

reference.

are

the rectifier,

SWEEP CIRCUITS,
POWER SUPPLY

is

is

tied to a voltage

In

this

supply,

BD-M-268

regulated and

,to

CR301,

series

reg-

+loo- and

4-37. -150-VOLT DC REGULATED POWER SUP- (See figure 5-9.

PLY. The -150-volt supply (figure 5-91 in the 120B

is

used as a reference supply for the +300-, +loo-, CR304 and capacitor C328 for rectifier and filter.

and

+99-volt supplies; therefore, any change in the

-150 volt supply is reflected as a change inthese sup­ply voltages. The ac voltage from T302
and partially filtered by rectifier

CR303 and capaci-

is

rectified

4-40.
ments of vertical amplifiersvland V2) uses rectifier

Transistor

tial across Zener diode CR302 for its voltage refer­ence. The current in transistor
value of the dc voltage across the filaments.

+19-VOLT DC REGULATED POWER SUPPLY.

)

The +19-volt supply (for the

Q301

is

a

series regulator using the poten-

Q301 determines the

fila-

Section IV

Paragraphs 4-41 to 4-48

-

Model 120B

-

REGULATOR

V301

CONTROL

VOLTAGE

OSC~LLATOR

V302

FROM SWEEP
GENERATOR

4-41.

HIGH-VOLTAGE POWER SUPPLY.

4-42. BLOCK-DIAGRAM DESCRIPTION. (See fig­ure 4-6.) Oscillator V302 generates an ac voltage and
applies it to step-up transformer
up ac voltage
The negative high-voltage output of V303
the cathode of the crt, and the negative high-voltage
output of V304 is applied to the control grid of the crt.
The difference between the two voltages is the crt bias
and thus controls the crt intensity.

4-43. When the INTENSITY control setting

a

change occurs in the cathode high voltage, causing
a change in the voltage level at the wiper of the
volt adjust potentiometer. This results in regulator
V30l altering the control voltage in a direction neces­sary to return the cathode high voltage to
value; however, this now results in the control-grid

high voltage being higher or lower than previously
and thus the crt intensity

4-44. HIGH-VOLTAGE RECTIFIER

ure 5-10.) The ac high voltage present in one second­ary winding of T301
by capacitor
taken from the wiper of INTENSITY potentiometer

R321

is

effectively in series with and opposing the

high-voltage output of

ER pushbutton is depressed, the opposing voltage

from the wiper of potentiometer R321
removed and the intensity of the crt trace

4-45.
the signal is applied through capacitor C307 to the
cathode of the crt and thus modulates the crt intensity.

When a signal

-

,TRANSFORMER

c

is

applied to rectifiers V303 and V304.

is

is

rectified by V303 and filtered

C308. A portion of the +I00 volts dc

V303. When the BEAM FIND-

is

applied to the Z AXIS input,

HlGH
VOLTAGE
ADJUST

+300VDC

HIGH A-C

STEP-UP

T301

Figure 4-6. High-Voltage Power Supply, Block Diagram

T301. The stepped-

altered.

V303. (See fig-

VOLTAGE

HIGH A-C
VOLTAG E

UNBLANKING GATE

is

applied to

is

changed,

-2500-

its

original

is

effectively

is

increased.

HIGH-VOLTAGE

RECTIFIER

b

V303

I

/

A

[BEAM

bml

HIGH-VOLTAGE

RECTIFIER

V304

4-46. A voltage-divider network, consisting of re­sistors
eters R312 (FOCUS control) and R308 (-2500 adjust),
is tied between
crt. The voltage present at the wiper of R312 is ap-

plied to the crt focusing grid as focusing voltage, and

the voltage present at the wiper of R308

amplifier V301B as the high-voltage control voltage.

4-47. AMPLIFIER V301. (See figure 5-10. ) When a

change in the value of the high voltage occurs, a cor­responding change occurs at the wiper of potentiom­eter
and the resultant change in the plate voltage is dc

coupled through R305 to the control grid of
This, in turn, results in a change in the plate voltage
of
oscillator
high voltage decreases, the screen grid voltage of
V302 increases to a point where the increasedac out-

put of V302 restores the high voltage to its original

value.

4-48. HIGH-VOLTAGE RECTIFIER V304. (See fig­ure 5-10.
ondary of transformer T301 is rectified by V304 and
filtered by capacitor
high voltage is applied through resistor
control grid of the crt. The positive side of the high
voltage is applied through resistor R326 to the hori­zontal sweep circuits, wherein the unblanking gate is
generated. When the positive-going unblanking gate is
generated, the crt control grid bias becomes less neg­ative and the crt is unblanked.

R313, R311, R310, R309, R307, potentiom-

+300 volts dc and the cathode of the

R308. This alters the bias at the grid of V301B,

V301A, which is connected to the screen grid of

V302. The overall effect is that when the

)

The ac high voltage across the other sec-

&2500VDC + CATHODE

FINDER^

.

=

C310. The negative side of the

TO

OF CRT

TO CONTROL

+GRID OF

CRT

ED-M-269

is

applied to

R327 to the

V301A.

Model 120B

Section V

Paragraphs 5-1 to 5-8

SECTION

MAINTENANCE

5-1.

INTRODUCTION.

5-2. This section provides maintenance and service
instructions for the Model 120B Oscilloscope.
cluded are troubleshooting, repair, adjustment, per­formance checks, and diagrams.

5-3.

TEST

5-4'

maintain

characteristics can be substituted.

EQUIPMENT.

5-1

lists

the

the

120B'

test

equipment

Equipment

required

with

5-5. TROUBLESHOOTING.

5-6. The troubleshooting procedures are divided into
two categories: system troubleshooting, which

5-

Table

In-

to

is

used

1.

Recommended Test Equipment

V

to isolate a malfunction to aparticular functional sec­tion of the Model 120B; and sectional troubleshooting,
which

is

used to locate the faulty detail part. Figures

5-1 through 5-4 show the location of parts whose des­ignations are not directly imprinted on

or chassis.

5-7.

SYSTEM TROUBLESHOOTING.

5-8. Most troubles occurring in the Model 120B will
directly affect the display on the crt; consequently, the

system-troubleshooting procedures are based on the

most common types of faults detectable by crt obser­vations.
that occur in oscilloscope displays, together with the

circuits most likely to be at fault. After finding the
faulty section, refer to the sectional troubleshooting
procedures.

able-5-2

lists

the common types of defects

a

circuit board

Item

No.

1

2

3

4

5

Test

Oscilloscope

Precision
DC Voltmeter

High-Voltage
DC Voltmeter

Audio
Oscillator

AC Voltmeter

Characteristics

Bandwidth: dc to at least
600 kc. Sensitivity:
10

mv/cm to 100 v/cm,

Voltage range: 10-300 volts.
Accuracy:
Input impedance: 1 megohm.

Voltage range: 3000 volts.
Accuracy: 8%.
Input impedance: 100
ohms.

Frequency range: 50 cps
to 450 kc.

Voltage range:

300 v.
Accuracy:
on scale used.

Frequency Range: 50 cps

to

450 kc.

*I%.

meg-

1

mv

to

3% depending

Use

Observation of waveforms.

Voltage measurements.

Voltage measurements.

Source of sine-wave
signal.

I

Voltage measurements.

Model No.

Hewlett-Packard

140A.

Hewlett- Packard
Model

412A.

Hewlett- Packard
Model 410C with
Model
Voltage Divider

Hewlett- Packard
Model

Hewlett- Packard
Models

11045A

Probe

200CD.

400~/~/L.

Section V
Paragraphs 5-9 to 5-14

Table 5-

1.

Recommended Test Equipment (Cont'd)

Model 120B

Item

No.

6

7

8

9

Type

Square Wave
Generator

Voltmeter
Calibrator

Time Mark
Generator

Power
Transformer

Auto-

Characteristics

Frequency range: 1 kc to
100 kc.
Rise time: Less than

0.2

pet.

Amplitude: To 50 volts
peak- to-peak.

Accuracy:

Marker intervals: decade
steps from 10
100 msec.
Accuracy:

Output voltage: 103-127
volts ac (for 115-volt
input to
254 volts ac (for 230­volt input to 120B).

0.5%.

wec to

1%.

120B); 206-

Use

Source of square wave.

Accurate source of ac
and dc voltages.

Set sweep times.

Vary line voltage.

Model No.

Hewlett- Packard
Model

211A.

Hewlett-Packard

Models

Tektronix 180.

General Radio
Type

738A/~.

WlOHM.

10

5-9.

5-10. GENERAL.
tional section, a visual inspection should be per­formed. Check for open fuse, broken wires, dis­colored parts, leaky capacitors, etc. The best meth­od for checking tubes is by substitution.

5-11. HORIZONTAL AND VERTICAL AMPLIFIERS.
In the event of vertical or horizontal troubles such as
unbalance or no deflection, check plate voltages,
starting at the input stage and working toward the crt.
Be sure the position controls are centered, no signals
are applied, and the HORIZONTAL DISPLAY switch

is

set to an external horizontal input position. Make
detailed voltage checks (see paragraph 5-67) in the
first stage with incorrect plate voltages.

of frequency response troubles, check tubes first (by

substitution) then frequency-compensating devices
such as trimmer capacitors, neutralizing and bypass
capacitors.

5- 12. SWEEP GENERATOR. With the exception of

trigger generator

form a feedback loop; consequently,
functional stage in the loop results in abnormal wave­forms appearing in all stages of the loop. For this

reason, voltage readings are the best means for lo­cating troubles in the sweep generator circuit. Voltage
measurements for both the start-of-sweepand end-of-

sweep circuit conditions are listed on figure 5-8. In

Attenuator

SECTIONAL TROUBLESHOOTING.

Prior to troubleshooting any func-

V201, the sweep generator circuits

Attenuation: 110 db in 1-db
steps.
Power capacity: 5 watts.

In

the event

a

failure in any

Attenuation

the event of sweep failure, it

voltage measurements be employed to isolate the trou-

ble. A10 to
be expected, a larger deviation indicates a source of
trouble.

5-13. LOW
checking the power supplies, check the

plyfirst, for it affects all supplies. Check the other

supplies in any order. Check all vacuum tubes and
transistor

paragraph 5- 67). Voltage and ripple tolerances are

given in table 5-4.

5-14.

HIGH-VOLTAGE POWER SUPPLY.

15% deviation from the values given can

-

VOLTAGE POWER SUPPLY. When

Q301;

if

normal, make voltage checks (see

CAUTION

Do not operate the Model 120B with
incorrect power supply voltages for
prolonged periods of time. Where
the procedure calls for a measure­ment, turn the instrument on just
long enough to make the measure­ment; then turn the instrument off
again.

WARNING

Use caution when measuring high
voltages. Use equipment suited for
high-voltage measurements.

Hewlett-Packard
Model

is

350D.

recommended that both

-

150-volt sup-

Model 120B

Section V

Paragraph 5- 15

Figure 5-1.

5-15. Measure the voltages supplied to the crt.
they are normal, replace the crt.
are-not present, check that oscillator V302

lating. Note that a fault in the crt cathode supply af­fects the crt grid supply, whereas a fault in the crt
grid supply has no effect on the cathode supply.
both crt supplies are excessively high, or both exces-

sively low, make voltage checks on V301 (see para-

graph 5-67).

Top View, Location of Parts and Adjustments

Zf

If

the high voltages

is

oscil-

If

Note

Do not reset high voltage adjustment
R308 unless the need for
ment

is

clearly indicated. The ad-

justment of high voltages affects the

sensitivity of the crt and makes nec­essary the readjustment of vertical

and horizontal gain and time scales.

suchadjust-

Section V

Figure 5-2

Model 120B

Figure 5-2. High-Voltage Power Supply, Location of Parts

Symptom

Nothing visible on crt with
BEAM FINDER pressed.

Vertical sensitivity out of
specifications on

tivity ranges; horizontal

sweep normal.
Vertical sensitivity out of

specifications on one range.

External horizontal
tivity out of specifications;
vertical sensitivity normal.

Faulty sweep; external
zontal deflection normal.

all

sensi-

sensi-

hori-

Table 5-2. System Troubleshooting

Probable Trouble

1.

Low-voltage power supply.

2. Vertical amplifier.

3. Horizontal amplifier.

4. High-voltage power supply.

5. Crt.

1.

Vertical amplifier.

2. VERTICAL SENSITIVITY
switch S2.

1.

Horizontal amplifier.

1.

Sweep generator circuits.

Paragraph Reference

1.

Paragraphs 4-34 and 5-13

2. Paragraphs 4-10 and 5-11

3. Paragraphs 4-30 and 5-11

4. Paragraphs 4-41 and 5-14

5. Paragraph 5-21

1.

Paragraphs 4-10 and 5-11

1.

Paragraphs 4-30 and 5-11

1.

Paragraphs 4-16 and 5-12

Poor focusing; intensity

normal.

Poor intensity.

1.

High-voltage power supply.

2. Crt

1.

Low-voltage power supply.

2. High-voltage power supply.

3.

Crt

1.

Paragraphs 4-41 and 5-14

2. Paragraph 5-21

1.

Paragraphs 4-34 and 5-13

2. Paragraphs 4-41 and 5-14

3. Paragraph 5-21

1

Model 120B

Section

Paragraphs 5-16 to 5-22

V

Figure 5-3.

5-16.

5-17. REPLACEMENT OF SEMICONDUCTORS.

5-18. Excessive heat can destroy semiconductors.
When solderingor unsoldering transistors or diodes,
place a heat-sink (such as long-nose pliers) on the

lead of the part; in addition, isolate the Model 120B
from ground, or ground the body of the soldering iron

to prevent leakage current

5-20. Figure 5-5 illustrates the recommended

od of servicing etched circuit boards.

REPAIR.

When replacing
of silicone grease (hp Stock No.

0059) on each side of the insulator to
improve heat transfer from transistor
to deck.

SERVICING ETCHED CIRCUIT BOARDS.

VerticalSensitivity (A2) and Trigger Source (A201)Switches, Locationof Parts and Adjustments

f

rom damaging the part.
Note
Q301, use a thin coat

8500-

meth-

Removal of

components, such as tube sockets, that are attached
to the board at more than two points is difficult when
trying to remove the part intact. Simplify the removal
by first cutting the pins or other connections between
the body of the part and the circuit board, and then

remove the pins individually.

5-21. CRT REPLACEMENT.

WARNING

When replacing the crt, handle crt
with care; wear gloves and plastic
face mask or goggles.

5-22. Replace the crt as follows:

a. Remove four mounting screws from bezel, and

remove bezel.

b. Loosen clamp screw (figure 5-1) on crt base; do

not remove screw or clamp.

Section V
Paragraphs 5-23 to 5-34

Model 120B

5-26. The following paragraphs, 5-27 through 5-51,

describe the adjustments necessary to align the Model

120B.

5-27. LOW-VOLTAGE POWER SUPPLY

5-28. Table 5-4
age outputs of the low-voltage power supply.
voltage is not within tolerance it is probable that the
line voltage
or the replacement of a tube or part has caused the
misadjustment.

ply and line voltage are normal and the voltages are

not within tolerance, adjustment

5-29. -150-VOLT ADJUSTMENT. Using a dc VTVM,
adjust potentiometer R352 (figure 5-1) for -150 volts
dc.

5-30.

justment for the

faulty transistor or part
in the -150-volt power supply.

5-31.
justment for the

a faulty tube or part is indicated, or a fault exists in
the -150-volt power supply.

5-32.

is

a faulty tube or part
the -150-volt power supply.

+19-VOLT ADJUSTMENT. There

+300-VOLT ADJUSTMENT. There

+loo- AND +99-VOLT ADJUSTMENT. There

no adjustment for these outputs;

If

the +300 volts dc
ance and the
dc are not within tolerance, a fault
exists in V308 or associated parts.

lists

the tolerances of the dc volt-

is

abnormal, a malfunction has occurred,

If

it

is

confirmed that the power sup-

is

then required.

is

no ad-

+19-volt output; if out of tolerance a

is

indicated, or afault exists

is

no ad-

+300-volt output;

is

indicated, or a fault exists in

Note

is

+I00 and/or +99 volts

if

out of tolerance

if

out of tolerance

within toler-

If

any

Figure 5-4. Right-Side View, Side Panel Removed,

Location of Parts and Adjustments

c. Remove socket from crt base.
d. Slide crt forward and out.
e. Replace in reverse order.

.

Energize the Model 120B and obtain a free-

f

running trace.

If

necessary, align graticule and trace by ad-

g.

justing SCALE control.

5-23.

5-24. ADJUSTMENTS FOLLOWING REPAIR.

5-25. Table 5-3

lowing the replacement of a tube, transistor, or
diode.
table

item.

ADJUSTMENTS.

lists

the adjustments required fol-

If

a part associated with an item listed in the

is

replaced, check the adjustment of the listed

5-33. HIGH-VOLTAGE POWER SUPPLY.

5-34. Adjust the high-voltage power supply as follows:

Note

Adjustment of the high voltage affects
crt deflection sensitivity, intensity,

focus, and astigmatism.

izontal and vertical gain adjustments
following any adjustment of the high
voltage. Intensity, focus, and astig-

matism adjustments are included in
the following adjustment of the high-

voltage power supply.

WARNING

Voltages in excess of 2,500 volts are
present in the high-voltage power

supply. Take all possible precau­tions when performing high-voltage
measurements.

a. Connect high-voltage voltmeter between terminal

17 or 18 of transformer T302 and ground.

b. Adjust potentiometer R308 (figure 5-1) for a

voltmeter reading of -2500 volts.

Checkhor-

Model

120B

Figure

SERVICING ETCHED CIRCUIT BOARDS

Excessive heat or pressure can lift the copper strip from the board. Avoid damage by using a low power

(50

soldering iron

be cemented in place with a quick drying acetate base cement having good electrical insulating properties.

A

break in the copper should

Use only high quality rosin core solder when repairing etched circuit boards. NEVER USE PASTE FLUX.
After soldering, clean off any excess flux and coat the repaired area with a high quality electrical varnish

or lacquer.
When replacing components with multiple mounting pins such as tube sockets, electrolytic capacitors, and

potentiometers, it will be necessary to lift each pin slightly, working around the components several times
until it is free.

WARNING:
eyelets are not followed, extensive damage to the etched circuit board will result.

1. Apply heat sparingly to lead of component to be
replaced.

an eyelet in thecircuit board, apply heat on com-

ponent side of board.

not pass through an eyelet, apply heat to con-

-

ductor side of board.

watts maximum) and following these instructions. Copper that lifts off the board should

be

repaired by soldering a short length of tinned copper wire across the break.

If

the specific instructions outlined in the steps below regarding etched circuit boards without

2.

If

lead of component passes through

If

lead of component does

-

Reheat solder in vacant eyelet and quickly in­sert a small awl to clean inside of hole.
does not have an eyelet, insert awl or a
drill from conductor side of board.

Section

If

hole

#57

5-

V

5

4.

3.

Bend clean tinned leads on new part and care­fully insert through eyelets or holes in board.

In the event that either the circuit board has been damaged or the conventional method
method shown below. This is especially applicable for circuit boards without eyelets.

1. Clip lead as shown below.

CLIP

HERE

This procedure is used in the field only as an alternate means of repair. It is not used within the factory.

C

Hold part against board (avoid overheating) and
solder leads. Apply heat to component leads on
correct side of board as explained in step

is

impractical, use

2.

Bend protruding leads upward. Bend lead of
new component around protruding lead. Apply

solder using a pair of long nose pliers as a
heat sink.

APPLY

SOLDER

1.

Figure

Servicing Etched Circuit Boards

5-5.

5-7

Section V
Table 5-3

Model 120B

I

Reference

Designation

v1

V5

Table 5-3. Adjustments Following Tube, Transistor, and Diode Replacement

Function

Amplifier

Vertical Amplifier

I

1.

Balance adjustment (figure 3-5)

Adjustment and Paragraph

I

2. Gain adjustment (paragraph 5-37)

I

Amplifier

Amplifier

Calibrator
Calibrator

1

3. Neutralization adjustment (paragraphs 5-38
and 5-40)

1.

Balance adjustment (figure 3-5)

2. Gain adjustment (paragraph 5-37)

3. Neutralization adjustment (paragraphs 5-39

and 5-40)

1. Balance adjustment (figure

2. Gain adjustment (paragraph 5-37)

3. Neutralization adjustment (paragraph 5-39)

None

1.

Calibrator adjustment (paragraph 5-41)

3-5)

I
I

VlOl

V201

V202

Amplifier

I

I

I

Trigger generator

I

Start-stop trigger
Clamp and hold-off

cathode follower
Gate-out cathode

follower
Sawtooth integrator

and cathode follower

Horizontal Amplifier

1. Gain adjustment (paragraph 5-43)

X1

2.

3. Neutralization adjustment (paragraph 5-44)

1

1.

Gain adjustment (paragraph 5-43)

I

2. X1 Sweep adjustment (paragraph 5-49)

1

3. Neutralization adjustment (paragraph 5-44)

Sweep Generator

Trigger sensitivity adjustment (paragraph 5-47)
Preset adjustment (paragraph 5-46)

Sweep time adjustment (paragraph 5-50)

Preset adjustment (paragraph 5-46)

Sweep adjustment (paragraph 5-49)

I

I

I

None

None

V208
V209

CR201 Switch diode

Sweep length adjustment (paragraph 5-51)

None

None
None

Model 120B

Section V

Paragraphs 5-35 to 5-37

!

Table 5-3. Adjustments Following Tube, Transistor, and Diode Replacement

Reference

Designation

I

Function

Amplifier
Oscillator
Rectifier
Rectifier
CRT

Low-Voltage Power Supply
Regulator
Amplifier-output

cathode follower
Regulator
Amplifier

High-Voltage Power Supply

Adjust horizontal gain (paragraph 5-43)

i

(

I

Adjust vertical gain (paragraph 5 -3 7)
Adjust sweep times (paragrabh 5-448)

I

Adjust -150 volts (paragraph 5-29)

Adjustment and Paragraph

(Cont'd)

None

None

None

Reference tube
Heater regulator
Rectifiers

Reference diode

Table 5-4. Low-Voltage Power Supply Voltages

Voltage**

-150 volts dc

+

19 volts dc
+300 volts dc
+I00 volts dc

+

99 volts dc

*Line voltage 115 or 230 volts ac, as required.

**With respect to chassis ground.

c. Switch HORIZONTAL

and

center the spot.

d- Set INTENSITY control to 9 o'clock and adjust

~320 (figure 5-1) to the point where the spot just
extinguishes.

,

e. hcrease INTENSITY control and adjust FOCUS

control for best spot. 5-37. GAIN ADJUSTMENT. Adjust the

f.

Adjust Astigmatism control R316 (figure 5-1)

for small round spot readjusting FOCUS control as a. Set VERTICAL SENSITIVITY to 10

required.

DISPI.AY to 1 VOLTS/CM

Tolerance*

VTVM Accuracy

-1.5 volts; +1 volt

*9

volts
*3 volts
*3 volts

(+3%)

Adjust -150 volts (paragraph 5-29)

None
None
None

Typical

Ripple

45 mv
45 mv
15 mv
15 mv

5-35.

VERTICAL AMPLIFIER.

5-36. BALANCE ADJUSTMENT. Adjust the vertical

amplifier balance as described in figure 3-5.

plifier gain as follows:

VOLTS/CM.

5 mv

**

Resistance

4K (with

Typical

VlOl removed

7 5K

verkical am-

**

MILLI-

Section V

Paragraphs 5-38 to 5-44

Model 120B

b. Set vertical VERNIER to CAL.

c. Using voltmeter calibrator, apply a 400-cps

0.1-volt peak-to-peak signal to the vertical input
terminals.

d. Adjust CAL screwdriver adjustment for a

deflection of 10 cm.

5-38.
TION AND FIRST-STAGE-NEUTRALIZATION AD­JUSTMENTS.
ator-frequency compensation and first-stage neutral­ization as follows:

input terminals.

VOLTS/CM.

plitude for 10 cm of deflection on crt.
wave pattern on crt.

deflection on crt.
tern on crt.

wave pattern is obtained at the extreme vernier settings.

deflection on crt.
wave pattern on crt.

deflection on crt.
wave pattern on crt.

ATTENUATOR

Adjust the vertical amplifier

a. Connect square-wave generator

b. Rotate vertical VERNIER fully counterclockwise.
c. Set VERTICAL SENSITMTY to 100 MILLI-

d. Set vertical AC-DC to AC.

e. Set HORIZONTAL DISPLAY to 0.5

f . Adjust output of generator to 1 kc and set am­g. Adjust capacitor C6 (figure 5-3)for best square­h. Rotate vertical VERNIER to CAL.

i.

Readjust square-wave generator for 10 cm of

j. Adjust

k. Repeat adjustment of C6 and

1. Set VERTICAL SENSITMTY to

m.

Readjust square-wave generator for 10 cm of

n. Adjust capacitor C4 (figure

o. Set VERTICAL SENSITMTY to 10
p. Readjust square-wave generator for 10 cm of

q. Adjust capacitor C2 (figure 5-3)for best square-

C9 (figure 5-4) for best square-wave pat-

There may be a capacitor in par-

allel with
timize the adjustment range of
When changing V1

sary to alter the value of the ca-

pacitor, or add it

-

FREQUENCY - COMPENSA-

to

the vertical

MSEC/CM.

C9 until best square-

Note

C9 which serves to op-

it

may be neces-

if

not present.

5-3)for best square-

C9.

1

VOLTS/CM.

VOLTS/CM.

crt

attenu-

.

Adjust C12 and C13 (figure 5-1) simultaneously,

j

forthe best square wave on both test oscilloscope and
scope under test.

Notes

Ignore the very fast overshoot at the
leading edge as viewed on monitor
scope.

There may be a capacitor inparallel
with C13 which serves to' optimize
the adjustment range of C13. When

changing V2 or V3 it may be neces-

sary to alter the value of the capaci-

it

if

tor, or add

5-40. SECOND-STAGE VERTICAL NEUTRALIZA­TION ADJUSTMENT. Adjust the second-stage verti­cal neutralizers as follows:

a. Rotate vertical VERNIER to CAL.
b. Repeat steps b through h of paragraph 5-39.

c. Adjust

for best square wave on scope.

5-41. CALIBRATOR ADJUSTMENT. Adjust the out-

put of the calibrator as follows:

a. Adjust vertical gain as described in paragraph

5-37.

b. Set VERTICAL SENSITIVITY to CAL.
c. Turn vertical VERNIER to CAL.
d. Set HORIZONTAL DISPLAY to

ONDS/CM.

e. Set TRIGGER SOURCE to INT-.

f

.

Turn TRIGGER LEVEL to AUTO.

g. Adjust potentiometer R51 (figure 5-1) for a crt

deflection of

C10 and C11 (figure 5-1) simultaneously

There may be a capacitor in parallel

C10 which serves to optimize

with
the adjustment range of
changing

sary to alter the value of the capaci-

tor, or to add

V1 or V2 it may be neces-

6

cm.

not present.

Note

it

if

not present.

C10.

When

1

MILLISEC-

5-39. THIRD-STAGE VERTICAL-NEUTRALIZATION
ADJUSTMENT. Adjust the third-stage vertical neu­tralizers as follows:

a. Rotate vertical VERNIER fully counterclock-

wise.

b. Set VERTICAL SENSITIVITY to 10 MILLI-

VOLTS/CM.

c. Set vertical AC-DC
d. Set HORIZONTAL DISPLAY to 5
e. Set TRIGGER SOURCE to INT+.
f . Turn TRIGGER LEVEL to AUTO.
g. Using square-wave generator, apply a 100-kc

square wave to vertical input terminals.

h. Adjust generator output to give 10-cm deflec-

tion, and center the pattern vertically.

i. Using test oscilloscope, monitor the cathode of

v3.

to

AC.

pSEC/CM.

5-42.

HORIZONTAL AMPLIFIER.

5-43. GAIN ADJUSTMENT. Adjust horizontal gain

as follows:

a. Set HORIZONTAL DISPLAY to

b. Turn horizontal VERNIER to CAL.

c. Using voltmeter calibrator, apply a 400-cps

1-volt peak-to-peak signal to the horizontal input

terminals.

d. Adjust horizontal gain potentiometer R104 (fig-

ure 5-1) for a peak-to-peak crt deflection of 10 cm.

5-44. HORIZONTAL NEUTRALIZER ADJUSTMENT.

Adjust horizontal neutralization as follows:

a. Set VERTICAL SENSITIVITY to
b. Turn vertical VERNIER to CAL.

c. Set HORIZONTAL DISPLAY to

d. Turn horizontal VERNIER to CAL.

.1

VOLTS/CM.

1

VOLTS/CM.

.1

VOLTS/CM.

Model 120B

Section V

Paragraphs 5-45 to 5-54

e. Using oscillator, apply an 8-kc sine wave to
vertical input terminals and the sync input of
wave generator.

f. Using square-wave generator, apply a 100-kc

1-volt peak-to-peak square wave to horizontal input

terminals.

g. Adjust oscillator frequency to synchronize sine
wave and square wave on crt (stabilize presentation).

h. Adjust C103 and C104 (figure 5-1) for best

square- wave response.

5- 45. ATTENUATOR FREQUENCY- COMPENSATION
ADJUSTMENT. Adjustthe horizontal attenuator fre­quency compensation

a. Set VERTICAL SENSITIVITY to
b. Turn vertical VERNIER to CAL.
c. Turn horizontal VERNIER to

d.

Set HORIZONTAL DISPLAY to 1 VOLTS/CM.

e. Using square-wave generator, apply a 1-kc
10-volt peak-to-peak square wave to the horizontal
input terminals.

f. Using oscillator, apply an 800-cps 10-volt
peak-to-peak signal to the vertical input and sync in­put of square- wave generator.

g. Adjust oscillator to synchronize sine wave and

square wave on crt (stabilize presentation).

h. Adjust capacitor C235 (figure 5-1) for optimum

square wave on crt.

i.

Set HORIZONTAL DISPLAY to 10 VOLTS/CM.

j.

Increase square-wave generator output to 50

volts peak- to-peak.

k. Adjust capacitor C233 (figure 5-1) for optimum

square-wave on crt.
5-46, PRESET ADJUSTMENT. Adjust preset as

follows:

a. Set VERTICAL SENSITIVITY to CAL.

b. Set HORIZONTAL DISPLAY to
oNDS/CM.

c. Set TRIGGER SOURCE to INT+.

d. Turn TRIGGER LEVEL just out of AUTO.

e. Connect dc voltmeter (-100-volt range) between
pin 2 of V202 and ground.

f. Adjust potentiometer
until crt sweep free-runs, then counterclockwise until
thesweep just stops; note the readings on thevoltmeter.

g. Adjust voltage to 3 volts less negative than the

last reading.

5-47. TRIGGER-SENSITIVITY ADJUSTMENT. Ad­just the trigger sensitivity

a. Set VERTICAL SENSITIVITY to 100
CM.

b.

SetHORIZONTALDISPLAY to 5 MILLISECONDS/

C M.

c. Turn both VERNIER controls to CAL.

d.

Set TRIGGER SOURCE to EXT.

e. Turn TRIGGER LEVEL to AUTO.

f. Set SWEEP MAGNIFIER to X5.

g. Set vertical and horizontal AC-DC switches to AC.

h. Connect oscillator to both the VERTICAL and
HORIZONTAL inputs and set the frequency to 450 kc
and amplitude to 0.16 volts rms (using

400D/~/L AC VTVM).

i.

Adjust R203 (trigger sensitivity) fully counter-

clockwise.

as

follows:

1

CAL.

.5 MILLISEC-

R258 (figure 5- 1) clockwise

as

follows:

square-

VOLTS/CM.

MILLIVOLTS/

hp Model

j. Observing crt presentation, adjust

wise until the presentation becomes stable.

k. Adjust oscillator output amplitude down to 0.1 v

rms, presentation should become slightly unstable

between 0.15 and 0.10 v rrns.

1. Set oscillator output amplitude to 0.5 v rms, and

adjustfrequency from 50 cps to 450 kc. Presentation

should remain stable across complete f requency range.

5-48.

SWEEP

5-49. X1 SWEEP ADJUSTMENT. Adjust the X1
sweep

CM.

time markers to the vertical input terminals.
5 cycles per 10 cm on the crt.

5-50. SWEEP-TIME ADJUSTMENT. Adjust the hor-

izontal sweep time

terminals.
generator output and the HORIZONTAL DISPLAY

switch to the indicated marker interval and sweep time,
respectively, for each step; adjust or check for the
indicated markers per 10 cm listed in the table.

5-51. SWEEP LENGTH ADJUSTMENT. Adjust the
sweep length as follows:

CM.

oNDs/CM.

length of 10.75 cm (minimum length on any range

be 10.5 cm).

as

a. Set VERTICAL SENSITIVITY to
b. Turn vertical VERNIER
c. Turn horizontal VERNIER to CAL.
d. Set HORIZONTAL DISPLAY to 5 MILLISECONDS/

e. Set SWEEP MAGNIFIER to

f. Set TRIGGER SOURCE to INT-

g. Turn TRIGGER LEVEL to AUTO.

h. Using time mark generator, apply 100-cps

i.

Adjust X1 sweep gain R267 (figure 5-1) to obtain

a. Set VERTICAL SENSITMTY to
b. Turn vertical VERNIER to CAL.
c. Turn horizontal VERNIER to CAL.
d. Set TRIGGER SOURCE to INT-.
e. Set SWEEP MAGNIFIER to

f. Connect time mark generator to the vertical input

g. Referring to table 5-5, adjust the time mark

a. Set VERTICAL SENSITIVITY to 100
b. Turn vertical VERNIER to CAL.

c. Set vertical AC-DC to AC.
d. Set HORIZONTAL DISPLAY to

e. Turn horizontal VERNIER to CAL.
f. Set SWEEP MAGNIFIER to
g. Set TRIGGER SOURCE to INT-.
h. Turn TRIGGER LEVEL to AUTO.

i.

Adjust potentiometer R254 (figure 5-1)fora sweep

5-52.

5- 53. The following paragraphs, 5- 54 through 5- 66,
list thevarious performance checks to determine that
the Model 120B

5- 54. VERTICAL ATTENUATOR- ERROR CHECK.
Check the vertical attenuator error as follows:

a. Set vertical AC-DC to DC.

b. Set VERTICAL SENSITIVITY to 10

CM.

c. Turn vertical VERNIER to CAL.

GENERATOR.

follows:

tO

CAL.

Xl.

as

follows:

XI.

Xl.

PERFORMANCE CHECK.

is

performing properly.

R203 clock-

1

VOLTS/CM.

.

1

VOLTS/CM.

MILLIVOLTS/

.5 MILLISEC-

MILLIVOLTS/

should

Section V

Paragraphs 5-55 to 5-56

Model 120B

Table 5-5. Horizontal Sweep-Time Adjustment

Step

1

2

3
4
5
6
7

8
9

10
11

12
13

Marker

Interval

10 psec
10 psec

10 psec
100 psec
100 psec
100 psec

1

ms

1

ms

1

ms
10 ms
10 ms

10

ms

100 ms

Sweep Time

~SEC/CM

5

10 pSEC/CM

20 pSEC/CM

50 pSEC/CM

100

~SEC/CM

200 pSEC/CM

.5

MILLISECONDS/CM

1

MILLISECONDS/CM

2

MILLISECONDS/CM

5

MILLLSECONDS/CM

10

MILLISECONDS/CM

20

MILLISECONDS/CM

50

MILLISECONDS/CM

Adjust

C227

*

C227
C227

*

C225

*

C225
C225

*

C223

*

C223
~233

*

~267
~267

*

~267

*

R247

Markers

per 10 cm

5

10

20

5

10

20

5

10

20

5

10

20

5

*

100

14
15

*

Do not adjust if indication

d. Using voltmeter calibrator, apply a 400-cps g. Vertical shift should be approximately 0.2 cm

0.1-volt peak-to-peak signal to the vertical input or less.
terminals.

e. Adjust CAL for a crt deflection of exactly
f. Set VERTICAL SENSITMTY to 100 MILLI-

VOLTS/CM.

g. Adjust voltmeter calibrator output to 1 volt

peak-to-peak.

h. Vertical deflection should be 10

peat step for

CAL SENSITIVITY switch, adjusting voltmeter cali-

brator output to

spectively; vertical deflection should be 10
in both cases.

5-55. VERTICAL DC
shift as follows:

a.

Set VERTICAL SENSITIVITY to 10 MILLI-

VOLTS/CM.

b. Set vertical AC-DC to AC.

c. Turn vertical VERNIER to CAL.

d.

Short vertical input terminals to ground.

e.

SwitchHORIZONTALDISPLAY to 10 VOETS/CM,

and

observe

f.

Switchvertical AC-DCswitch

the

spot.

the

100 ms
100 ms

is

within 50.5 cm of that listed in the "markers per 10 cm" column.

*0.3 cm. Re-

1

and 10 volts/cm positions of VERTI-

10

and 100 volts peak-to-peak, re-

SHIFT CHECK Check the dc

spot.

to

DC,

MILLISECONDS/CM

200

MILLISECONDS/CM

10cm.

*0.3 cm

and'

observe

5-56. VERTICAL FREQUENCY-RESPONSE CHECK.
Check vertical frequency response as follows:

a. Set VERTICAL SENSITMTY to 10 MILLI-

VOLTS/CM.

b. Turn vertical VERNIER to CAL.

c. Set vertical AC-DC to AC.

d.

Set TRIGGER SOURCE to

e. Turn TRIGGER LEVEL to AUTO.

f. Set HORIZONTAL DISPLAY to

ONDS/CM.

g. Usingoscillator, apply a 4.5-kc signal

of attenuator; adjust for 10-db of attenuation.

h. Connect the output of attenuator to the vertical

input terminals.

i.

Set oscillator output to provide 10 cm of verti-

cal

deflection.

j.

Monitor output with ac voltmeter and note voltage

reading.

k.

Maintaining voltage reading in step

oscillator frequency to 450 kc.

1. Display amplitude should

to-peak.

R247
R247

*

INT+.

be

at

10

20

1

MILLISEC-

to

the input

j,

least 7 cm

change

peak-

Model 120B

Paragraphs 5-57 to 5-65

Section V

5-57. HORIZONTAL DC SHIFT CHECK. Check dc
shift as follows:

.1

a: Set HORIZONTAL SENSITIVITY to

CM.

b. Turn horizontal VERNIER to CAL.

c. Short horizontal input terminals.

d. Center spot and alternately switch horizontal

AC-DC to AC and DC positions.

e. Spot should shift less than 0.2 cm.

5-58. HORIZONTAL ATTENUATOR-ERROR CHECK.

Check attenuator error as follows:

a. Set HORIZONTAL DISPLAY to
b. Turn horizontal VERNIER to CAL.
c. Using voltmeter calibrator, apply a 400-cps

1-volt peak-to-peak sine wave to the horizontal input

terminals.

d. Adjust horizontal gain potentiometer R104 (fig-

ure 5-1) to give 10-cm deflection.

e. Change HORIZONTAL DISPLAY to

CM and voltmeter calibrator output to 10 volts peak-

to-peak.

.

Horizontal deflection should be 10 &0.5 cm.

f
g. Change HORIZONTALSENSITIVITY to 10 VOLTS/

CM and voltmeter calibrator output to 100 volts peak-

to-peak.

h. Horizontal deflection should be 10

5-59. HORIZONTAL PHASE-SHIFT CHECK. Check

phase shift as follows:

a. Set VERTICAL SENSITIVITY to 100

VOLTS/CM.

b. Turn vertical VERNIER to CAL.

c. Set HORIZONTAL DISPLAY to
d. Turn horizontal VERNIER to CAL.
e. Set vertical and horizontal AC-DC to AC.

f. Using oscillator, apply

peak-to-peak sine wave to both vertical and horizontal

input terminals.

g. Pattern opening on crt should be less than 0.2

(+2 degrees).

cm

h. Change VERTICAL SENSITIVITY to

CM, HORIZONTAL DISPLAY to

voltmeter calibrator output to

i.

Indication should be same as step g.

j

.

Change VERTICAL SENSITMTY to 10 VOLTS/
CM, HORIZONTAL DISPLAY to 10
voltmeter calibrator output to 50 volts peak-to-peak.

k. Indication should be same as step g.

5-60. HORIZONTAL RESPONSE CHECK.

quency response as follows:

a. Set HORIZONTAL DISPLAY to
b. Turn horizontal VERNIER to CAL.

c. Using oscillator, apply

the horizontal input terminals.

d. Set oscillator output to provide a 10-cm trace.
e. Monitor output with ac voltmeter and note voltage

reading.

~aintaining voltage reading in step e, change

f.

oscillator frequency to 300 kc.

g; Trace length should be greater than 7 cm (3-db

point).

5-61. EXTERNAL TRIGGER-SENSITIVITY CHECK.

Check external trigger sensitivity as follows:

a.

Set VERTICAL SENSITIVITY to 1 VOLTS/CM.

.1

.1

a

100-kc 0.5-volt

1

VOLTS/CM, and

5

volts peak-to-peak.

VOLTS/CM, and

a

4.5-kc signal.

VOLTS/

VOLTS/CM.

1

VOLTS/

*0.5 cm.

MILLI-

VOLTS/CM.

1

VOLTS/

Checkfre-

1

VOLTS/CM.

to

b. Set vertical AC-DC to AC.

c. Turn vertical VERNIER to CAL.
d. Set HORIZONTAL DISPLAY to 5
e. Set TRIGGER SOURCE to EXT.

.

Set TRIGGER

f

g. Using oscillator, apply a sine wave to

the vertical and horizontal input terminals.

h. Vary oscillator frequency from 50 cps to 450
kc, maintaining a 0.53-volt input (1.5 volts peak-to­peak).

i. Presentation should be stable over frequency
range in step h.

5-62. SYNC
RANGE CHECK. Check syne polarity and trigger­level range as follows:

a. Set VERTICAL SENSITIVITY to 10
b. Turn vertical VERNIER to CAL.

c. Set TRIGGER SOURCE to EXT.

d. Apply a 7.0-volt r-m-s 400-cps signal to ver-

tical and external sync inputs.

e. Center pattern on crt.

f

.

Rotate TRIGGER LEVEL; triggering should be

possible at any point along the negative slope of the

input signal.
5-63. SWEEP-TIME CHECK. Check the sweep times

as follows:

a. Set VERTICAL SENSITMTY to
b. Turn vertical VERNIER to CAL.

c. Set horizontal VERNIER to CAL.

d. Set SWEEP MAGNIFIER to

e. Set TRIGGER SOURCE to INT-.

f.

Adjust TRIGGER LEVEL for best synchroniza-

tion.

g. Connect time mark generator to vertical input

terminals.

h. Referring to table 5-6, adjust the time mark

generator output and the HORIZONTAL DISPLAY

switch to the indicated markers and setting, respec­tively, for each step; check for the indicated markers
per 10 cm listed in the table.

5-64. CALIBRATOR AMPLITUDE CHECK. Check
the amplitude of the calibrator as follows:

a. Set VERTICAL SENSITIVITY to CAL.
b. Turn vertical VERNIER to CAL.

c. Set HORIZONTAL DISPLAY to

OND/CM.

d. Set TRIGGER SOURCE to INT-.

e. Turn TRIGGER LEVEL to AUTO.

f

.

Calibrator amplitude should be 6 *0.12 cm.

5-65. INTENSITY MODULATION CHECK. Check
intensity modulation as follows:

a. Set VERTICAL SENSITIVITY to 10
b. Turn vertical VERNIER to CAL.
c. Set HORIZONTAL DISPLAY to 50

CM.

d. Using ,square-wave generator, apply

20-volt peak-to-peak square wave to the vertical in­put terminals.

e. Remove shorting bar from Z
connect clip lead from vertical input to Z axis ter­minal.

f.

With

normal intensity, the top edge of square

shouI&

wave

peak square wave

LEVEL

-

POLARITY AND TRIGGER- LEVEL-

be

extinguished when 20-volt peak-to-

is

to AUTO.

applied at

XI.

the

pSEC/CM.

VOLTS/CM.

1

VOLT/CM.

1

MILLISEC-

VOLTS/CM.

pSECONDS/

axis

terminal and

Z

axis terminal.

a

both

50-kc

Section V

Paragraphs 5-66 to 5-69

Model 120B

Table 5-6. Horizontal Sweep Time

Step

1

2
3
4
5

6

7

8

9

10

11

12
13
14
15

Marker
Interval

10 psec
10 psec

10 psec
100 psec
100 psec
100 psec

1

ms

1

ms

1

ms

10

ms

10

ms

10

ms

loo

ms

loo

ms

loo

ms

Sweep Time

~SEC/CM

5

10

~SEC/CM

20 pSEC/CM
50 pSEC/CM

100

~SEC/CM

200

~SEC/CM

.5

MILLISECONDS/CM

1

MILLISECONDS/CM

2 MILLISECONDS/CM
5

MILLISECONDS/CM

10

MILLISECONDS/CM

20

MILLISECONDS/CM

50 MIL~ECONDS/CM

loo

MILLISECONDS/CM

200

MILLISECONDS/CM

Markers

per 10 cm*

5

10

2 0

5
10
20

5
10

o

2

5

10

2

o

5

10

20

5- 66. LINE-VOLTAGE VARIATION CHECK. Check

line-voltage variation as follows:

a. Connect power cable to power autotransformer

and adjust output to 115 volts ac.

b. Set VERTICAL SENSITIVITY to CAL.
c. Set HORIZONTALDISPLAY

CM.

d. Set TRIGGER LEVEL to AUTO.
e. Adjust horizontal VERNIER to obtain exactly 5

cyclesof calibrator signal per 10 cm; note exact am-

plitude of each calibrator signal.

to

f. Set line voltage

ac. (Allow periods of at least

)

voltage.

+0.3 cm; the five cycles of the signal should change
less than 0.5 cm in length.

5-67.

5-68. Figures 5-6 through 5-11 are schematic dia­grams of the Model
on the schematics as an aid in troubleshooting.

5-69. The following notations are applicable to fig­ures 5-6 through 5-11.

a. All values are in ohms, picofarads, and

henries unless otherwise indicated.

b. Lettering enclosed in heavy boxes indicates

panel engraving.

c. Voltage measurements are with respect

and made with Hewlett-Packard Model 412A VTVM.

Calibrator signal amplitude should be 6

DIAGRAMS.

103 volts ac, then to 127 volts

120B. DC voltages are provided

to

2 MILLISECONDS/

2 minutes for each

micro-

front-

to

ground

d. Voltage measurements are

front-panel controls set as follows:

Control Setting
VERTICAL SENSITIVITY switch CAL
VERTICAL VERNIER control CAL
Vertical AC-DC switch AC
FOCUS control Centered
VERTICAL POSITION control Centered
INTENSITY control Centered

HORIZONTAL POSITION control Centered
HORIZONTAL DISPLAY switch 5
HORIZONTAL VERNIER control CAL
TRIGGER SOURCE switch
TRIGGER LEVEL control AUTO
Horizontal AC-DC switch AC

SWEEP MAGNIFIER switch

madewith Model 120B

@EC/CM

INT-

X1

01260-2

Model 120B

+99VF

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Section

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REFERENCE

DESIGNATIONS

UNASSIGNED

C20
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NOTES

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UNLESS OTHERWISE INDICATED

2

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AVERAGE VALUE SHOUN

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Test

V202

pin

1

pin

9 -41

pin

8

pin

6 +26.5

pin

2 -150

V203

pin

2 -55
3 +I30

pin

I

pin
pin

8 -55

V2M

pin

6 +26.5

pin

7 +29

V205

pin

2 -8.5

pln

6 +240

pin

CONDITIONS OF MEASUREMENT OF

~VER~SENSITIVITY

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SWITCH IN

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WIVEFORMS:

9 +I30

pin

8 +I30
V206 (R225
V201 (R252
V208 (V209
V209 (I3244
R242/R243
R244/R245

**Reset: Connect

side)
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slde)

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*SweepCompleted: Connect

Sweep

Completed*

15 volts

-8.

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-52

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+I85
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V202

pin 2 to ground.

volts
volts
volts
volts

volts
volts
volts
volts

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volts

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volts
volts
volts

volts
volts
volts
volts
volts

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0

volts
volts
volts
volts
volts

volts
volts
volts
volts

volts
volts

volts volts

volts
volts

volts
volts
volts
volts
volts
volts

-

15Ova

Figure

5-8.

Sweep

Generator

5-17

1361 V3 V102 V3oI V302

V308

-

TO

SELECTOR

I ALL

PICOFARADS AND MILLIHENRIES.
UNLESS OTHERWISE INDICATED.

2

X - AVERAGE VALUE SHOWN

NOTE

VALUES

ARE

IN

onus.

OPTIMUM VALUE SELECTED
AT FACTORY. PART MAY BE
OMITTED

:

Model 120B

TWINLEAD

FROM

IMP.

VERT.

Section V

Figure 5-10

(

I.

ALL VALUES IN 0HMS.PICOFARADS AND
MILLIHENRIES UNLESS OTHERWISE
NOTE0

NOTE

A302

COPPER

[PARTS

SHIELD

MOUNTED

-

ON

73011

DESIONATIWS

GAT'EI+I

FROM PIN7

OF

VPO4

Figure 5-10. High-Voltage Power Supply

5- 19

Section

Figure

V

5

-1

1

Model 120B

Figure 5-11. Horizontal

Display

Switch

Model 120B

Section

VI

Paragraphs 6-1 to 6-6

SECTION

VI

REPLACEABLE PARTS

6-1.

INTRODUCTION.

6-2. This section contains information for ordering
replacement parts. Table 6-1 lists parts

in.alpha-

numerical order of their reference designations and

indicates the description and hp part number of each
component, together with any applicable notes. Parts
not identified

by

a reference designation are listed
under miscellaneous at the end of Table 6-1. Table
6-2 lists parts in alpha-numerical order of their hp

6-3.

6-4. To order a replacement part, address order or

inquiry to your local Hewlett-Packard
Office (see list of addresses at rear of this manual),
andsupply the hp part number of the

tables.

6-

the following information:

part number and provides the following information
on each item:

a. Description of the part (see list of abbreviations

below).

instrument.

b. Typical manufacturer of the part in a five-digit

code, except where Hewlett-Packard Company

is

the

manufacturer. See list of manufacturer codes in location.

Table 6-3.

c. Manufacturer's part number.
d. Total quantity used in the instrument

(TQ

6-6. To order apart from a manufacturer other than
Hewlett-Packard Company, provide the
part description and the m&ufacturerls part number

column) from Table 6-2.

ORDERING INFORMATION.

5.

To order a part not listed in the tables, provide

a. Model number of the instrument.
b. Complete serial number (eight digits) of the

c. Description of the part including function and

~ales/~ervice

item(s) from the

-

-

-~

.

com~lete

.-- . .

-

---

r----

=

assembly

=

motor

=

capacitor

=

coupling

=

diode

=

delay line

=

device signaling (lamp)

=

A

A.F.C

AMPL

B.

F.O.

BE
BH

BP

BRS
BWO

CCW
CER

CMO

COEF

COM

COMP

CONN

CP

--

CRT

CW

DEPC
DR

ELECT

ENCAP = encapsulated
EXT

F
FH

Flt

FXD

amperes

=

automatic frequency control

=

amplifier

=

beat frequency oscillator

=

beryllium ,copper

CU

=

binder head

=

bandpass

=

brass

=

backward wave oscillator

=

counter-clockwise

=

ceramic

=

cabinet mount only

=

coefficient

=

common

=

composition

=

connector

=

cadmium plate

=

cathode-ray tube

=

clockwise

=

deposited carbon

=

drive

=

electrolytfc

=

external

=

farads

=

flat head

H

=

fillister
fixed

head

=

REFERENCE

=

misc electronic part

=

fuse

=

filter

=

jack

=

relay

=

inductor

=

meter

=

GE

GL

GRD

H
HEX

Ha

IIP

HB

IF
IMPG

MCD
INCL
INS
INT

K

LIN

LK

LOG

LPF

M
MEG
METFLM = metal film

MFR
MINAT

MOM

MTG

MY

N

germanium

=

glass

=

ground(ed)

=

henries

=

hexagonal

=

mercury

=

Hewlett-Packard

=

hour(8)

=

intermediate freq

=

impregnated

=

incandescent

=

include(s)

=

insulation(&)

=

internal

=

kilo = 1000

=

linear taper

WASH

=

lock washer

=

logarithmic taper

=

low pass filter

=

milli = 10-3

=

met?=

=

manufacturer

=

miniature

=

momentary

=

mounting

=

"mylar"

=

nano(10-4

lo6

DESIGNATORS

ABBREVIATIONS

=

mechanical part

=

plug

=

transistor

=

resistor

=

thermistor

=

switch

=

transformer

=

N/C
NE

NI

N/O

NPO

NRFR

NSR

OBD
OH

OX

P

PC

PF

PA
PHL

PN

P/O

POLY
PORC = porcelain

POS

POT

PP

PT

RECT

RF

RH

normally closed

=

neon

=

nickel plate

PL

=

normally open

=

negative positive zero
(zero temperature
coefficient)

=

not recommended for
field replacement

=

not separately
replaceable

=

order

=

oval head

=

oxide

-

-

peak
printed circuit

=

picofarads

=

10-12 farads

phosphor bronze

BRZ

=

Phillips

=

peak inverse voltage

=

part of

=

polystyrene

=
=

position(s)

=

potentiometer

=

peak-to-peak

=

point

=

rectifier

= radio frequency
=

round head

by

description

=

TI3

=

TP

V
W

X
Y

RMO = rack mount only

RMS

S-B

SCR

SE

SECT
SCMICON = semiconductor

SI

SIL
SL
SPL
SST
SR
STL

TA

TD
TCL = toggle
TI

TOL

TRIM = trimmer

TWT

u

VAR

VDCW

W/
W

WW

W/O

terminal board

=

test point

=

vacuum tube, neon
bulb, photocell, etc.

=

cable

=

socket

=

crystal

=

root-mean-square

=

slow-blow

=

screw

=

selenium

=

section(s)

=

silicon

=

silver

=

slide

=

special

=

stainless steel

=

split ring

=

steel

=

tantalum

=

time delay

=

titanium

=

tolerance

=

traveling wave tube

=

micro = 10-6

=

variable

=

dc working volts

=

wlth

=

watts

=

wirewound

=

wfthout

Section VI

Table 6-1

Table 6-

Reference Designation Index

1.

Model 120B

Reference

Designation

A1
A2

A3 THRU
A2 00
A201

A202
A203

A2 04
A205 THRU
A300

A301
A302

C1
C2
C 3
C4
C5

C6
C7
C8
C9
C10

hp Part No.

120B-65F
120B-19A

120B-19D
120B-65G

120B-65D

120B-19B

120B-65E
120B-llB

0170-0022
0130-0014
0140-0186
0130-0014
0140-0180

0130-0014
0140-0147
0150-0012
0132-0004
0132-0004

#

ASSY:

Description

ETCHED CIRCUIT, VERTICAL AND HORIZONTAL

AMPLIFIER

ASSY: SWITCH, VERTICAL
NOT ASSIGNED

ASSY: SWITCH, TRIGGER SOURCE
ASSY: ETCHED CIRCUIT, SWEEP

AND

LOW VOLTAGE

SUPPLY
ASSY: ETCHED CIRCUIT, HORIZONTAL SWITCH
ASSY:

SWITCH,

HORIZONTAL (INCLUDES A203)
NOT ASSIGNED
ASSY:

ETCHED CIRCUIT, HIGH VOLTAGE SUPPLY

ASSY: RECTIFIER

FXD MY 0.1

C:

pf

20% 6OOVDCW
C: VAR CER 5-25 pf
C: FXD MICA 20K pf

1%

3OOVDCW
C: VAR CER 5-25 pf
C: FXD MICA 2K pf 2%, 3OOVDCW

C: VAR CER 5-25 pf
C: FXD MICA 180 pf

5% 500VDCW
C: FXD CER 10K pf 20% lOOOVDCW
C: VAR POLY 0.7-3 pf 350VDCW
C: VAR POLY 0.7-3 pf 350VDCW

Note

C11
C12
C13
C14

C15
C16

C17
C18
C19
C20

C21
C22 THRU
ClOO
ClOl
C102

C103
C104
C105 THRU
C200
C201

C202
C203
C204
C205
C206

0132-0004
0132-0004
0132-0004
0150-0014
0150-0012

01 70- 0003
01 50- 0011
01 50- 0041
01 50- 0012

0150-0011

0170-0022
0150-0012

0132-0002
0132-0004

0150-0011
01 50- 0024

0140- 0201
0150-0011
0180-0050
0180-0050

C: VAR POLY 0.7-3 pf 350VDCW
C: VAR POLY 0.7-3 pf 350VDCW
C: VAR POLY 0.7-3 pf 350VDCW
C: FXD CER 0.005

pf

500VDCW

C: FXD CER 10K pf 20% lOOOVDCW

C: FXD MY 0.051
C: FXD TI-OX 1.5

pf

10% 2OOVDCW

pf

20% 500VDCW
C: FXD TI-OX 2.7 pf 5% 500VDCW
C: FXD CER 10K pf 20% lOOOVDCW
NOT ASSIGNED

C: FXD TI-OX 1.5 pf

NOT

ASSIGNED

C:

FXD MY 0.1

20% 500VDCW

pf

20% GOOVDCW

C: FXD CER 10K pf 20% 1OOOVDCW
C: VAR POLY 0.7-3 pf 350VDCW

C: VAR POLY 0.7-3 pf 350VDCW
NOT ASSIGNED

C: FXD TI-OX 1.5 pf 20%

500VDCW

C: FXD CER 20K pf -20% +80% 6OOVDCW
C: FXD MICA 12 pf

5%

500VDCW

C: FXD TI-OX 1.5 pf 20% 500VDCW

C:

FXD ELECT 40

C: FXD ELECT 40

pf

-15% +loo% 500VDCW

pf

-15% +loo% 500VDCW

#

See introduction to this section

01260-2

Model 120B

r

Reference

Designation

hp

Table 6-

Part

No.

1.

Reference Designation Index (Cont'd)

Description

Section VI

Table 6-1

#

Note

C207
C208
C209
C210
C211

C212
C213
C214
C215
C216

C217 THRU
C220
C221
C222
C223

C224
C225
C226
C227
C228

C229
C230
C231
C232

C233

0140-0039
0140-0082
0140-0156

0150-0023

0140-0041

0150-0024
0150-0012
0140-0041
0150-0012

0170-0028
0170-0027
0131-0003

0170-0026
0131-0004
0140-0041
0130-0019
0170-0038

0170-0027
0160-0007
0140-0031
0140-0055
0130-0016

FXD MICA 47

C:

pf 5% 5OOVDCW
C: FXD MICA 68 pf 5% 500VDCW
C: FXD MICA 1500 pf 20% 3OOVDCW
NOT ASSIGNED
C: FXD CER 2000

pf 5% lOOOVDCW

C: FXD MICA 100 pf 5% 5OOVDCW
C: FXD CER 20K pf -20% +80% 6OOVDCW
C: FXD CER 10K pf 20% 1OOOVDCW
C: FXD MICA 100 pf 5% 500VDCW
C: FXD CER 10K pf 20% lOOOVDCW

NOT ASSIGNED

FXD MY 0.2

C:

FXD MY 0.02

C:

pf

5%2OOVDCW

pf

5% BOOVDCW

C: VAR MICA 170-780 pf 175VDCW
C: FXD MY 0.0018

pf

5% 200VDCW
C: VARMICA 14-150pf 175VDCW
C: FXD MICA 100 pf 5% 5OOVDCW
C: VAR CER 4-30 pf 500VDCW
C: FXD MY 0.22 pf 10% 200VDCW

C: FXD MY 0.02

C: FXD MY 0.0022

pf

5% 2OOVDCW

pf

10% 6OOVDCW

C: FXD MICA 220 pf 10% 500VDCW
C: FXD MICA 150 pf 10% 500VDCW
C: VAR CER 5-25 pf 500VDCW

C234
C235
C236
C237
C238 THRU
C300

C301
C302
C303
C304
C305

C306
C307
C308
C309
C310

C311
C312
C313
C314
C315 THRU
C320

0140-0156
0130-0016
0140-0027
0140-0035

0150-0023

0140- 0037
0140- 0004
0150-0024
0160-0151

0150-0012
0160-0151
0160-0151
0160-0039
0160-0151

0150-0023
0160-0151
0160-0151
0160-0151

C: FXD MICA 1.5K pf 20% JOOVDCW
C: VAR CER 5-25 pf 5OOVDCW
C: FXD MICA 470 pf 10% 500VDCW
C: FXD MICA 39 pf 5% 5OOVDCW

NOT ASSIGNED
C: FXD CER 2000 pf

20% lOOOVDCW
C: FXD MICA 390 pf 5% 500VDCW
C: FXD MICA 15 pf 10% 500VDCW
C: FXD CER 20K pf -20% +80% 6OOVDCW
C: FXD CER 4700 pf -20% +80% 4000VDCW

C: FXD CER 10K pf 20% lOOOVDCW
C: FXD CER 4700 pf -20% 40% 4000VDCW
C: FXD CER 4700 pf -20% +80% 4000VDCW
C: FXD MY 0.27

pf

10% 200VDCW

C: FXD CER 4700 pf -20% +80% 4000VDCW
C: FXD CER 2000 pf 20% '0OOOVDCW

C: FXD CER 4700 pf -20% 40% 4000VDCW
C: FXD CER 4700 pf -20% +80% 4000VDCW
C: FXD CER 4700 pf -20% +80% 4000VDCW

NOT ASSIGNED

#

See introduction to this section

6-3

Section VI
Table 6-1

Table 6-

1.

Reference Designation Index (Cont'd)

Model 120B

Reference

Designation

C321
~322~/~
C323
c324A/~/C
C325A/~

C326
C327
C328
C329

CR1 THRU

CR200

CR201
CR202 THRU
CR300

CR301
CR302
CR303
CR304
CR305

DS

1

F1 THRU
F300
F301

hp Part No.

0180-0126
0180-0030
0150-0024
0180-0053
0180-0127

0150-0024
0150-0012
0180-0056
0150-0024

1901-0044

1901-0030
1901-0030
1901-0030
1901-0045
1902-0225

1450-0048

2110-0005
2110-0020

Description

FXD ELECT

C:
C: FXD ELECT 2 SECT 120 x 40
C: FXD CER 20K pf -20% '080% 6OOVDCW
C: FXD ELECT 3 SECT 40-30-20

C: FXD ELECT 2 SECT 120 x 40
C: FXD CER 20K pf -20% +80% GOOVDCW

C: FXD CER 10K pf 20% lOOOVDCW
C: FXD ELECT 1K
C: FXD CER 20K pf -20°/0 +80% 6OOVDCW

NOT ASSIGNED
DIODE: SILICON

NOT ASSIGNED
DIODE: SILICON 800 V

DIODE: SILICON 800 V
DIODE: SILICON 800 V

DIODE: SILICON

DIODE: SILICON AVALANCHE 18.7
LAMP: INDICATOR

NOT ASSIGNED

FUSE:
FUSE: CARTRIDGE 0.8 AMP S-B (FOR 230 V OPERATION)

CARTRIDGE 1.6 AMP S-B (FOR 115 V OPERATION)

120

pf

300VDCW

pf

50VDCW

#

pf

450VDCW

pf

150VDCW

pf

-10% +50% 3OOVDCW

V

Note

J1

52 THRU
JlOO
JlOl

5102 THRU
5300

5301

L1 THRU

L200
L201
L202 THRU

L300

L301
L302

5060-0633
5060-0632
0340-0091
0340-0086

5060- 0633
5060-0632
0340-0091
0340-0087

5060-0633

5060-0632
0340- 0091
0340- 0087

9140-0022

5060- 0409
9140-0029

-

CONSISTS OF:

NSR

BINDING POST: RED
BINDING POST: BLACK (1 USED)
INSULATOR: 3 HOLE (1 USED)
INSULATOR: 2 HOLE (1 USED)

NOT ASSIGNED
NSR

-

CONSISTS OF:
BINDING POST: RED (1 USED)
BINDING POST: BLACK (SHARED BY

INSULATOR:

INSULATOR: 3 HOLE (SHARED BY
NOT ASSIGNED
NSR

-

CONSISTS OF:

BINDING POST: RED (1 USED)
BINDING POST:
INSULATOR:
INSULATOR: 3 HOLE (SHARED BY

NOT ASSIGNED
INDUCTOR: FXD RF 500

NOT ASSIGNED

INDUCTOR: ALIGNMENT
INDUCTOR: FXD RF 100

3 HOLE (SHARED BY

3 HOLE (SHARED BY

(2 USED)

BLACK (SHARED BY

ph

10%

ph

JlOl

JlOl

AND 5301)

JlOl

AND 5301)

JlOl

JlOl

AND 5301)

JlOl

AND

AND 5301)

AND 5301)

5301)

-

#

See introduction to this section

01260-2

Model 120B

Table 6-1. Reference Designation Index

Section VI

Table 6-1

(Cont'd)

Reference

Designation

P1

P300
P301

&1 THRU
Q300

Q301
R1

R2
R3
R4
R5

R6
R7
R8
R9
R10

R11
R12
R13
R14
R15

THRU

hp Part No.

1850-0038
0686-1055

0727-0274

0727-0100
0727-0271
0727-0157

0727-0261
0727- 0208
0686-1055
0687-4711

0687- 1041
0687-1011
0687-

101

1

0730-0062
0727-0197

Description

NOT ASSIGNED

OF

NSR: PART

NOT ASSIGNED
TRANSISTOR:

R: FXD COMP 1M 5% 1/2W
R: FXD DEPC 1M
R: FXD DEPC 1K OHMS
R: FXD DEPC 990K OHMS
R: FXD DEPC 10K OHMS

R: FXD DEPC 900K OHMS
R: FXD DEPC lOOK OHMS
R: FXD COMP 1M 5% 1/2~
R: FXD COMP 470 OHMS 10% 1/2~

NOT ASSIGNED

FXD COMP lOOK OHMS 10% 1/2~

R:
R: FXD COMP 100 OHMS 10% 1/2~
R: FXD COMP 100 OHMS 10%
R: FXD DEPC 80K OHMS
R: FXD DEPC 59.48K OHMS

POWER CORD W1

2N301

1%

1/2~

1%

1/2~

1%

1%

1%
1%

1%

#

1/2~

1/2~

1/2~
1/2~

I/~W

1W

1%

1/2~

Note

R16
R17
R18

R19

R~OA/B

R21
R22

R23
R24
R2 5

R26 THRU
R30
R3

1

R3 2
R33

R34
R3 5
R36
R37
R38

R3

9

R40

1

R4
R42
R43

2100-0054
0727-0197
0686-5115
0686-7525
2100-0339

2100-0174
0687-

101
0687-1011
0686-5115
0686-7525

0730-0056

2100-1486

0730- 0024

0730-0056
0687-2231
0687-2231

101

0687­0687-1011

0690-8221
0689-2235
0689- 1635
0687-4731
0689-2235

1

R: VAR

R: FXD DEPC 59.48K OHMS
R: FXD COMP 510 OHMS 5% 1/2~
R: FXD COMP 7.5K OHMS 5% 1/2W
R: VAR COMP LOG 2 SECT lOOK

R:

W/SPDT SWITCH

1

R:
R:
R: FXD COMP 510 OHMS 5% 1/2~
R: FXD COMP 7.5K OHMS 5% 1/2~

NOT ASSIGNED
R:
R: VAR COMP
R: FXD DEPC 7.5K OHMS

R: FXD DEPC 68.38K OHMS
R: FXD COMP 22K OHMS 10% 1/2~
R: FXD COMP 22K OHMS 10% 1/2~
R: FXD COMP 100 OHMS 10% 1/2~
R: FXD COMP 100 OHMS 10% 1/2~

R: FXD COMP 8.2K OHMS 10%
R: FXD COMP 22K OHMS 5% 1W
R: FXD COMP 16K OHMS 5% 1W
R: FXD COMP 47K OHMS 10% 1/2~
R: FXD COMP 22K OHMS 5% 1W

WW

LIN 500 OHMS 10% 2W

1%

1/2~

OHMS/SECT
VAR COMP 500K OHMS 20%, 5% CW LOG TAPER 1/4W
FXD COMP 100 OHMS

FXD COMP 100 OHMS 10% 1/2~

FXD DEPC 68.38K OHMS

LIN

10% 1/2W

1%

'ow

300 OHMS 20% 3W

1%

1W

1%

1W

20%

I/~W

'ow

#

See introduction to this section

6-5

Section VI
Table

6-1

Table

6-

1.

Reference Designation Index (Cont'd)

Model

120B

Reference

Designation

R44
R45 THRU
R50

1

R5
R52

R53
R54
R55

THRU
Rl 00
RlOl

R102
R103
R104
R105
R106

R107
R108

RIOSA/B

RllO
Rlll

R112

R113
R114
R115

R116

hp

Part

0690-8221

2100-0102
0727-0246

0686-1055
0727-0055

0687- 1041
0687-1011

0687- 1011
2100-0182
0690-1041
0690- 1041

0687-3321
0687- 3341

2100-0258
0687-3341
0727-0274

101

0687-

0686-3935

0686-3935

0687- 101

0727-0274

No'

Description

FXD

R:

NOT ASSIGNED

R:
R: FXD

R: FXD
R: FXD

NOT ASSIGNED

R: FXD
R: FXD

R: FXD
R: VAR
R: FXD
R:

R: FXD

R: VAR

R:

R: VAR

R: FXD

1

1

R: FXD

R: FXD

R: FXD

R: FXD

R: FXD

COMP

VAR

COMP LIN

DEPC

COMP
DEPC

COMP
COMP

COMP
COMP LIN
COMP

FXD

COMP

COMP
COMP

VAR

COMP DUAL TANDEM LIN
COMP
DEPC

COMP

COMP

COMP

COMP
DEPC

8.2K

OHMS

500K

600K

OHMS

1M

5% 1/2~

201

OHMS

100K

OHMS

100

OHMS

100

OHMS

3.3K

lOOK

OHMS

lOOK

OHMS

3.3K

OHMS

330K

OHMS

330K

OHMS

1M

1%

100

OHMS

39K

OHMS

39K

OHMS

100

OHMS

1M

1%

10% 1W

OHMS

1%

1%

10% 1/2W

10% 1/2~
10% 1/2~

OHMS

10% 1W
10%

10% 1/2W
10% 1/2W

10% 1/2W

1/2~

10% 1/2W

5% 1/2~
5% 1/2~

10% 1/2~

1/2~

#

30% 1/5~

1/2W

1/2W

10% 1/3~

'ow

1M

20% 1/4~

Note

R117
R118

R119
R120
R121 THRU
R200

R201
R202
R203
R204
R205

R206
R207
R208
R209
R210

R211
R212
R213
R214
R215

R216
R217 THRU
R220
R221

R222

0692-3635
0692-3635
0689-7525
0687-4731

101

0687-

1

0687- 1851
2100-0154
0686-1 525
0689-2435

0727-0202
0687-1531
0687-3921
0689-2435
0687-3921

0727-0201
0687-1041
2100-0188
0686-1245
0686-2745

0727-0060

0687-6831

0687- 101

1

R: FXD
R: FXD
R: FXD
R: FXD

NOT ASSIGNED

R:
R: FXD
R:
R: FXD
R: FXD

R:

R: FXD
R: FXD
R: FXD
R: FXD

R: FXD
R: FXD
R: VAR
R: FXD
R: FXD

R: FXD

NOT ASSIGNED

R: FXD
R: FXD

COMP
COMP
COMP
COMP

FXD

COMP
COMP

COMP LIN

COMP
COMP

FXD

DEPC
COMP
COMP
COMP
COMP

DEPC
COMP
COMP LIN

COMP

COMP
DEPC

COMP

COMP

36K
36K

7.5K
47K

100

OHMS
OHMS

OHMS

OHMS

OHMS

5% 2W
5% 2W

5% 1W

10% 1/2W

10% 1/2W

1.8M 10% 1/2W

1K

OHMS

30% 3/10~

1.5K
24K

OHMS

83K

OHMS

15K

OHMS

3.9K
24K

OHMS

3.9K

71.56K
lOOK

200K

120K

270K

225

OHMS

68K

OHMS

100

OHMS

OHMS

OHMS
OHMS

OHMS
OHMS

OHMS

5% 1/2~

5% 1W

1%

10% 1/2~

10% 1/2W

5% 1W

10% 112~

OHMS

10% 1/2W

OHMS

5% 1/2~
5% 1/2~

1%

10% 1/2~

10% 1/2~

1/2~

1%

1/2~

20% 1/4~

1/2~

#

See introduction to this section

01 260-2

Model 120B

Table 6-

1.

Reference Designation Index (Cont'd)

Section VI

Table 6-1

Reference

Designation

R223
R224
R225
R226
R227

R228
R229
R230
R231 THRU
R240

R241
R242
R243
R244

R245
R246

R247
R248 THRU
R250
R251

R252
R253
R2 54
R255
R256

hp

Part No.

0686-2435
0690-1041
0687-2731
0687-6841

0727-0110
0693-1831

0686-1055
0686-2055

0687-4711
0689- 1835
0690-8231
0687-2731
0687-4711

0687-4741

2100-0094

0771-0006
0687- 1241

0687-1041
2100-0144
0686- 1035
0686-4345

Description

R: FXD COMP 24K OHMS 5% 1/2~
R: FXD COMP lOOK OHMS 10% 1W
R: FXD COMP 27K OHMS 10% 1/2~

R: FXD COMP 680K OHMS 10% 1/2~
R: FXD DEPC 1.5K OHMS

R: FXD COMP 18K OHMS 10% 2W
R: FXD COMP 1M 5% '012~
R: FXD COMP 2M 5% 1/2~

NOT ASSIGNED
R: FXD COMP 470 OHMS 10%

R:

FXD COMP 18K OHMS 5% 1W
R: FXD COMP 82K OHMS 10% 1W
R: FXD COMP 27K OHMS 10% 1/2~
R: FXD COMP 470 OHMS 10% 1/2~

R: FXD COMP 470K OHMS 10% 1/2~

R: VAR COMP LIN 50K OHMS 3% 1/4~
NOT ASSIGNED

FXD MET OX 27K OHMS

R:
R: FXD COMP 120K OHMS 10% 1/2~

R: FXD COMP lOOK OHMS 10% 1/2W
R: VAR COMP 250K OHMS 30% 1/4~
R: FXD COMP 10K OHMS 5% 1/2~

FXD COMP 430K OHMS

R:

1%

10% 4W

5% 1/2~

#

1/2~

1/2~

Note

R257
R258
R259
R260
R261

R262
R263
R264
R265
R266

R267
R268

R269
R270
R271

R272

R273
R274
~275A/B

R276

0687-2731
2100-0093
0687-2731

0687-1051
0727-0376

0727-0173
0727-0285
0727-0221
0687- 5631

2100-0094
0727-0132
0727- 0100
0687-6841
0727-0292

0727-0292
0727-0292
0727-0292

2100-0338
0687-3931

R: FXD COMP 27K OHMS 10% 1/2~

VAR COMP

R:

FXD COMP 27K OHMS 10% 1/2~

R:

NOT ASSIGNED

FXD COMP

R:
R: FXD DEPC 1.98M

FXD DEPC 20K OHMS

R:

FXD DEPC

R:

FXD DEPC 200K OHMS

R:
R: FXD COMP 56K OHMS 10% 1/2W

R: VAR COMP LIN 50K OHMS 3% 1/4~

FXD DEPC 4K OHMS

R:

FXD DEPC

R:

R: FXD COMP 680K OHMS 10% 1/2~

R: FXD DEPC 3M

FXD DEPC 3M

R:

FXD DEPC 3M

R:

FXD DEPC 3M

R:

R: VAR COMP LOG 2 SECT lOOK

(includes S103)

FXD COMP 39K OHMS 10%

R:

LIN 20K OHMS 20% 1/4~

1M 10% 1/2~

1%

1/2~

1%

1/2~

1.8M

1%

1/2~

1%

1/2~

1%

1/2~

1K OHMS

1%

1/2~

1%

1/2~

1%

1/2~

1%

1/2~

1%

1/2~

OHMS/SECT

1/2W

20% 1/4~

#

See introduction to this section

6-

7

Section VI
Table 6-1

Table 6-

1.

Reference Designation Index (Cont'd)

Model 120B

Reference

Designation

R277
R278
R279
R280 THRU
R300

R301
R302
R303
R304
R305

R306
R307
R308
R309
R310

R311
R312
R313
R314
R315

R316
R317
R318
R319
R320

hp Part No.

0687-2231
0687-2741
0687-1541

0687-1021
0687-1041
0693-1541
0690-5641
0687-1051

0687- 1551
0686-2455
2100-0096
0693- 5651
0693-5651

0693- 5651
2100-0105
0687- 5641
0687-2731
0687-6831

2100-0095
0687-6831
0687-2251
0687-3331
2100-0102

Description

R: FXD COMP 22K OHMS 10%
R: FXD COMP 270K OHMS 10% 1/2~
R: FXD COMP 150K OHMS 10% 1/2~

NOT ASSIGNED
R: FXD COMP

R: FXD COMP lOOK OHMS 10% 1/2W
R: FXD COMP 150K OHMS 10% 2W
R: FXD COMP 560K OHMS 10% 1W

R:

FXD COMP 1M 10% 1/2~

R: FXD COMP 1.5M 10% 1/2~
R: FXD COMP 2.4M 5% 1/2~
R: VAR COMP LIN 1M 30% 1/4~
R: FXD COMP 5.6M 10% 2W
R: FXD COMP 5.6M 10% 2W

R: FXD COMP 5.6M 10% 2W
R:

VAR COMP LIN 3.5M 30% 1/2~

FXD COMP 560K OHMS

R:

FXD COMP 27K OHMS

R:
R: FXD COMP 68K OHMS 10% 1/2~

R: VAR COMP
R: FXD COMP 68K OHMS 10% 1/2~
R: FXD COMP 2.2M 10% 1/2~
R: FXD COMP 33K OHMS 10%
R: VAR COMP LIN 500K OHMS 30% 1/5~

1K OHMS 10% 1/2~

10% 1/2W

10% 1/2~

LIN

lOOK OHMS 30% 1/4~

#

I/~W

I/~W

Note

R321
R322
R323
R324
R325

R326
R327
R328 THRU
R330

1

R33
R332

R333
R334
R335
R336

R337
R338
R339
R340
R341

2100-0171
0687-1041
0693-8251
0693-8251
0693-8251

0687-4731
0687-2751

0687-1041
0687-1041

0690-1841
06964741
0687-1051
0687-4731

0687-4711
0687-1021
0727-0235
0727-0218
0727-0378

R: VAR COMP LIN 200K OHMS 20% 1/4~ (INCLUDES S301)
R: FXD COMP lOOK OHMS 10% 1/2~
R: FXD COMP 8.2M 10% 2W
R:

FXD COMP 8.2M 10% 2W

R:

FXD COMP 8.2M 10% 2W

R: FXD COMP 47K OHMS 10% 1/2~
R: FXD COMP 2.7M 10% 1/2~

NOT ASSIGNED
R: FXD COMP

FXD COMP

R:

R: FXD COMP 180K OHMS 10% 1W
R: FXD COMP 470K OHMS 10% lW
R: FXD COMP 1M 10% l/2W

R: FXD COMP 47K OHMS 10% 1/2~
R: FXD COMP 470 OHMS 10% 1/2~

R: FXD COMP 1K OHMS 10% 1/2~
R: FXD DEPC 360K OHMS 10% 1/2~
R: FXD DEPC 180K OHMS
R: FXD DEPC 257.1K OHMS

lOOK OHMS 10% 1/2~
lOOK OHMS 10% 1/2W

1%

1/2~

1%

1/2~

..

#

See introduction to this section

01260-2

Model 120B

-

Reference

Designation

hp

Part No.

Table 6-

1.

Reference Designation Index (Cont'd)

Description

Section VI

Table 6-1

#

Note

R342
R343 THRU
R350
R351

R3 52
R353

R354
R355
R3 56
R357

R358
R359
R360

R361

R362
R363

~364A/~
R365

S

1

S2
s~A/B/c
S4 THRU
SlOO

SlOl
S102
S103
,9104 THRU

S200

0687-4711

0727-0287
2100-0144

0727- 0289

0687- 8241
0687-8231
0693-1031
0687-1831

0687-1 531
0687-1051

0699-0006
0699-0006

0767-0010

2100-0150

0687-3331

3101-0011
3101-0010

3101-0011
3101-0011

R: FXD COMP 470 OHMS 10% 1/2W
NOT ASSIGNED

R: FXD DEPC 2M
R: VAR COMP 250K OHMS 30% 1/4W

R: FXD DEPC 2.52M

R: FXD COMP 820K OHMS 10% 1/2W
R: FXD COMP 82K OHMS 10% 1/2W
R: FXD COMP 10K OHMS 10% 2W
R: FXD COMP 18K OHMS

R: FXD COMP 15K OHMS 10% 1/2W
R: FXD COMP 1M 10% 1/2W
NOT ASSIGNED
R: FXD COMP 4.7 OHMS
R: FXD COMP 4.7 OHMS 10% 1W

R: FXD MET OX 15K OHMS 5% 3W
R: VAR COMP DUAL TANDEM 10K OHMS 20% 1/4W
R:

FXD

COMP 33K OHMS 10% 1/2W

SWITCH: SLIDE 1 SECT 4 POS
NSR: PART OF A2 ASSY
SWITCH: PUSH DPDT

NOT ASSIGNED
SWITCH: SLIDE

SWITCH: SLIDE
NSR: PART OF

NOT ASSIGNED

1%

1/2W

1%

1

SECT 4 POS

1

SECT 4 POS

R275A/~

1/2W

1O0/0

1/2W

10% 1W

S201
S202
S203
S204
S205 THRU
S300
S301

T1 THRU
T300
T301
T302

V1
V2
V3
V4
V5

V6 THRU
VlOO
VlOl
V102
V103 THRU
V200

3100-0302

120A-llA-1
9100-0156

1932-0029
1932-0029
1932-0022
5080-041
5080-0417

1932-0029
1932-0022

7

NSR: PART OF A201 ASSY
NSR: PART OF R213
NOT ASSIGNED
SWITCH: ROT

NOT ASSIGNED
NSR: PART OF R321

NOT ASSIGNED
TRANSFORMER: HIGH VOLTAGE
TRANSFORMER: POWER

TUBE: ELECTRON
TUBE: ELECTRON 12AU7
TUBE: ELECTRON 6DJ8
TUBE: NEON GLOW
TUBE: NEON GLOW

NOT ASSIGNED
TUBE: ELECTRON
TUBE: ELECTRON 6DJ8

NOT ASSIGNED

#

See introduction to this section

4 SECT 18 POS

12AU7

12AU7

6- 9

Section VI
Table 6-1

Table 6-

1.

Reference Designation Index (Cont'd)

Model 120B

Reference

Designation

V201
V202
V203
V204
V205

V206
V207
V208
V209
V210 THRU
V300

V301
V302
V303
V304
V305

V306
V307
V308
V309
V310
V311

hp Part No.

1932-0022
1933- 0004
1932-0029
1921-0005
1933- 0004

5080-041
5080-0417
5080-0419
5080-0419

1932-0029
1923-0018
1920-0001
1920-0001
5083-0353

1921-0010
1933-0004
1921-0010
1923-0021
1940-0001

Description

#

Note

TUBE: ELECTRON 6DJ8
TUBE: ELECTRON 6U8
TUBE: ELECTRON

12AU7
TUBE: ELECTRON 6C4
TUBE: ELECTRON 6U8

7

TUBE: NEON GLOW

TUBE: NEON GLOW
TUBE: NEON GLOW
TUBE: NEON GLOW

NOT ASSIGNED
TUBE: ELECTRON

12AU7
TUBE: ELECTRON 6AQ5
TUBE: ELECTRON 5642
TUBE: ELECTRON 5642
CRT: P31 PHOSPHOR INTERNAL

GRATICULE

NOT ASSIGNED
TUBE: ELECTRON

12B4A
TUBE: ELECTRON 6U8
TUBE: ELECTRON

12B4A
TUBE: ELECTRON 6AU6
TUBE: ELECTRON 5651

W1
XV1

XV2
XV3
XV4 TH RU
XVlOO

XVlOl
XV102
XV103 THRU
XV200
XV201

XV202
XV203
XV204
XV205
XV206 THRU
XV300

XV301
XV302
XV303 THRU
XV306
XV307

XV308
XV309
XV310
XV311

8120-0050
1200-0062

1200-0062
1200-0062

1200- 0062
1200- 0062

1200-0062
1200-0062

1200-0062
1200-0053
1200-0062

1200-0062
1200-0053

1200- 0062
1200- 0062

1200-0062
1200-0053
1200-0053

CORD: POWER (INCLUDES

P301)

TUBE: SOCKET 9 PIN MINAT
TUBE: SOCKET 9 PIN MINAT
TUBE: SOCKET 9 PIN MINAT

NOT ASSIGNED
TUBE: SOCKET 9 PIN MINAT

TUBE: SOCKET 9 PIN MINAT

NOT ASSIGNED

TUBE: SOCKET 9 PIN MINAT
TUBE: SOCKET 9 PIN MINAT

TUBE: SOCKET 9 PIN MINAT

7

TUBE: SOCKET

PIN MINAT

TUBE: SOCKET 9 PIN MINAT

NOT ASSIGNED

TUBE: SOCKET 9 PIN MINAT

TUBE: SOCKET 7 PIN MINAT
NOT ASSIGNED

TUBE: SOCKET 9 PIN MINAT

TUBE: SOCKET 9 PIN MINAT

9

TUBE: SOCKET
TUBE: SOCKET

PIN MINAT

7

PIN MINAT

TUBE: SOCKET 7 PIN MINAT

#

See introduction to this section

01260-2

Model 120B

Table 6-

1.

Reference Designation Index (Cont'd)

Section VI

Table 6-

1

Reference

Designation

XQ1 THRU
XQ300
XQ301

hp

Part No.

1200-0041

120A-83A

120B-44A­0370-0026

0370-0037

0370- 0062

0370- 0084
0370- 01 13

0370-0114

5000- 0743
5020-0710
5020-0711

5020-0718
5060-0625
5060-0734
5060- 0758
5060- 0767

5083-0323
5083-0333
5083-0342

120A-83A

120A-83B
120A-83C
120A-83G
0370-0084

0693-4711
5083-0330
5083-0340
5083-0350
NONE
NONE

Description

NOT ASSIGNED

TRANSISTOR: SOCKET

MISCELLANEOUS

1

FILTER: AMBER (USED WITH CRT WITH
COVER: TOP
KNOB: POSITION CONTROLS
KNOB: HORIZONTAL
KNOB: VERNIER CONTROLS
KNOB: INTENSITY

KNOB: TRIGGER SOURCE SELECTOR
KNOB: TRIGGER LEVEL CONTROL
COVER: SIDE
BRACKET: LEFT RACK MOUNT
BRACKET: RIGHT RACK MOUNT

STRIP: LARGE FILLER
ASSY: LEFT CONNECTOR
FRAME: ASSY SIDE
COVER: BOTTOM
ASSY: FULL MODULE FOOT

CRT:
CRT:
CRT:

FILTER: AMBER (USED WITH CRT
FILTER: BLUE (USED WITH CRT WITH

GRATICULE: SCRIBED

FILTER: GREEN (USEDWITH CRT

KNOB: SCALE
R: FXD COMP 470 OHMS 10% 2W

CRT:
CRT:
CRT: P31 PHOSPHOR, WITHOUT INTERNAL GRATICULE

R: VAR 300 OHMS (CTS TYPE FGC-90)
LAMP: 6 VOLTS 200

P2 PHOSPHOR, INTERNAL GRATICULE
P7 PHOSPHOR, INTERNAL GRATICULE
PI1

PHOSPHOR, ALUMINIZED, INTERNAL

GRATICULE

P7 PHOSPHOR, WITHOUT INTERNAL GRATICULE

PI1

PHOSPHOR, WITHOUT INTERNAL GRATICULE

AND

VERTICAL

AND

FOCUS CONTROLS

SPECIAL ORDER CRT'S

OPTION 05

MA

(4 EACH) (GE 1768)

#

P7 PHOSPHOR)

SELECTORS

WITH

P7 PHOSPHOR)
PI1

WITH

P31 PHOSPHOR)

Note

PHOSPHOR)

1251-0038
1251-0039
1251-0041

120B-95B-1
0370- 0084
0686-3325
0687-4741
0761-0077
1854-0015
3100-0211

OPTION 06

CONNECTOR:
CONNECTOR:

CLAMP:

TERMINAL
KNOB: BLACK,
R: FXD COMP 3300 OHMS 5%
R: FXD COMP 470K OHMS 10% 1/2~
R: FXD METFLM 24K OHMS 5% 1W
TRANSISTOR: SILICON NPN
SWITCH

#

See introduction to

:

FEMALE (TYPE MS-3106A­MALE (TYPE MS-

CABLE (TYPE AN-3057-4) 2 EACH

OPTION 10

BOARD

ROTARY SPDT (SWEEP)

ASSY: (INCLUDES COMPONENTS)

1

ARROW, 1/4 INCH SHAFT

this

section

3102A- 10SL- 3P) 2 EACH

1/2~

10SL3S) 2 EACH

6-11

Section VI
Table 6-2

Model 120B

hp

Part

No.

120A-llA-1
120A-83A
120B-llB
120B-19A
120B-19B

120B-19D
120B-44A­120B-65D

120B-65E
120B-65F

120B-65G
120B- 95B-1

0130-0014
0130-0016
0130-0019

0131-0003
0131-0004
0132-0002
0132-0004
0140- 0004

Table 6-2. Replaceable

Description

TRANSFORMER: HIGH VOLTAGE

FILTER: AMBER
ASSY: RECTIFIER
ASSY: SWITCH, VERTICAL
ASSY: SWITCH, HORIZONTAL (INCLUDES

A203)

1

ASSY: SWITCH, TRIGGER SOURCE
COVER: TOP
ASSY: ETCHED CIRCUIT, HORIZONTAL

SWITCH

ASSY: ETCHED CIRCUIT, HIGH VOLTAGE

SUPPLY

ASSY: ETCHED CIRCUIT, VERTICAL AND

HORIZONTAL AMPLIFIER

ASSY: ETCHED CIRCUIT, SWEEP AND LOW

VOLTAGE SUPPLY

ASSY: TERMINAL BOARD

VAR CER 5-25

C:

VAR CER 5-25

C:
C: VAR CER 4-30

C: VAR MICA 170-780
C: VAR MICA 14-150
C: VAR POLY 0.7-3
C: VAR POLY 0.7-3

C: FXD MICA 15

pf

350VDCW

pf

500VDCW

pf

500VDCW

pf
pf
pf

pf

10% 5OOVDCW

#

pf

175VDCW

175VDCW
350VDCW
350VDCW

Parts

Mfr.

hP
hp
hp
hp

hP
hP

hp
hp
hP
hp

hp
hp

72982
72982
72982

72136

72136
72982
72982
76433

Mfr.

Part

No.

577-030-COP-39R
557-019-COP-39R
503-015-W-650

T52910
T51410-3
535-015-4R
535-009-4R

RCM15B150K

RS

TQ

11

10

11

11
11

11
10

10
10

10

10
10

1

3
2

1

11
11

11

11

2

6
11

0140-0027
0140-0031

0140-0035
0140-0037
0140-0039

0140-0041
0140-0055
0140-0082
0140-0147
0140-0156

0140-0180
0140-0186
0140- 0201
0150-0011
0150-0012

0150-0014
0150-0023
01 50- 0024
0150-0041
0160-0007

0160-0039

0160-0151
0170- 0003
0170- 0022
0170-0026

C: FXD MICA 470
C: FXD MICA 220
C: FXD MICA 39
C: FXD MICA 390
C: FXD MICA 47

C: FXD MICA 100
C: FXD MICA 150
C: FXD MICA 68
C: FXD MICA 180
C: FXD MICA 1500

C: FXD MICA 2000
C: FXD MICA 20K
C: FXD MICA 12
C: FXD TI-OX 1.5
C: FXD CER 10K

C: FXD CER 0.005
C: FXD CER 2K
C: FXD CER 20K
C: FXD TI-OX 2.7 pf 5% 5OOVDCW
C: FXD MY 0.0022 d 10% 6OOVDCW

C: FXD MY 0.27
C: FXD CER 4700
C: FXD MY 0.051
C: FXD MY 0.1
C: FXD MY 0.0018

pf

10% 500VDCW

pf

10% 500VDCW

pf

5% 500VDCW

pf

5% 500VDCW

pf

5% 5OOVDCW

pf

5% 5OOVDCW

pf

10% 500VDCW

pf

5% 5OOVDCW

pf

5% 500VDCW

pf

20% 3OOVDCW

pf

2% 3OOVDCW

pf

1%

3OOVDCW

pf

5% 500VDCW

pf

20% 500VDCW

pf

20% lOOOVDCW

pf

500VDCW

pf

20% 1000VDCW

pf

-20% +80% 6OOVDCW

pf

10% 2OOVDCW

pf

-20% +80% 4000VDCW

pf

10% 200VDCW

pf

20% 6OOVDCW

pf

5% 2OOVDCW

76433
76433
76433
76433
76433

76433

76433
76433
72136
72136

72136
72136
72136
78488
71590

04222
91418

91418
78488
56289

56289

71 590
00853
84411
84411

RCM20B471K
RCM20B221K
RCM15E390J
RCM15E391J
RCM15E47OJ

RCMlSElOlJ
RCM20B151K

RCM15E680J
DM15F181J
DM19F152G

DM19F202G
DM30F203F
DM15C120J
GA
13C DISC

Dl-4

JFO.

002-20%
BO. 02 GMV
TYPE GA OBD#
160P22296

160P27492

DA172-097CB

33M02151
HEW 7
60QUE18252

11

11

11

11

11

1

3
1

I

11

11

2

1

11

11
11

4

1

2

8

11

1

3

6

2

11
11

11

2

7

11

1

2

11

#

See introduction to this section

01260-2

Model 120B

Section VI

Table 6-2

hp Part No.

0170-0027
0170-0028
0170-0038
0180-0030
0180-0050

0180- 0053
0180-0056
0180-0126
0180-0127

0370-0026
0370-0037
0370- 0062

0370- 0084
0370-0113
0370-0114

0686- 1035
0686- 1055
0686-1245
0686- 1525
0686-2055

Table 6-2. Replaceable

Description

pf

FXD MY 0.02

C:

FXD MY 0.2

C:

FXD MY 0.22

C:
C: FXD ELECT 2 SECT 120 x 40
C: FXD ELECT 40

FXD ELECT 3 SECT 40-30-20

C:
C: FXD ELECT 1K
C: FXD ELECT 120
C: FXD ELECT 2 SECT 120 x 40

3OOVDCW

KNOB: POSITION CONTROLS
KNOB: HORIZONTAL

SELECTORS
KNOB: VERNIER CONTROLS
KNOB: INTENSITY AND FOCUS CONTROLS
KNOB: TRIGGER SOURCE SELECTOR
KNOB: TRIGGER LEVEL CONTROL

R: FXD COMP
R: FXD COMP 1M 5% 1/2W
R: FXD COMP 120K OHMS 5% '012~
R: FXD COMP 1.5K OHMS 5% 1/2W
R: FXD COMP 2M 5% 1/2W

5% 2OOVDCW

pf

5% 2OOVDCW

pf

10% 200VDCW

pf

pf

pf

10K OHMS 5% 1/2W

#

-15% +1000/o 5OVDCW

50VDCW

JOOVDCW

AND

VERTICAL

Parts

pf

450VDCW

pf

150VDCW

pf

-

10% +50%

(Cont'd)

Mfr.

84411
84411

56289
56289
56289

56289
56289
56289

56289

01121
01121
01121
01121
01121

hp

hp
hp
hp
hp
hp

Mfr.

Part

600UE20352
600UE20452
148P22492
D32352
D32538

OBD#
D32429
D36236

D36235

EB1035
EB1055
EB1245
EB1525
EB2055

-

No.

RS

TQ

2

1

11

11

1'1

1

2

11

11

11
11

2

0

2

0

2

0

3

0
10
10

11

1

4

11

11

11

0686- 2435
0686-2745
0686-3325
0686-3935
0686-4345

0686-5115
0686-7525
0687- 1011

1021

0687­0687-1041

0687- 1051
0687- 1241
0687-1531
0687- 1541
0687-1551

0687-1831
0687-1851
0687- 2231
0687-2251

0687-2731
0687- 2741

0687-2751
0687-3321
0687-3331
0687-3341

FXD COMP 24K OHMS

R:

FXD COMP 270K OHMS 5% '012~

R:
R: FXD COMP 3.3K OHMS 5% 1/2W
R: FXD COMP 39K OHMS 5% 1/2~
R: FXD COMP 430K OHMS 5% 1/2W

R: FXD COMP 510 OHMS 5% 1/2W
R: FXD COMP 7.5K OHMS 5% 1/2~
R: FXD COMP 100 OHMS 10% 1/2W
R: FXD COMP 1K OHMS 10% 1/2~
R: FXD COMP lOOK OHMS 10% 1/2W

R: FXD COMP 1M 10% 1/2W
R: FXD COMP 120K OHMS 10% 1/2~
R: FXD COMP 15K OHMS 10% 1/2~
R: FXD COMP 150K OHMS 10% 1/2W
R: FXD COMP 1.5M 10% 1/2~

R: FXD COMP 18K OHMS 10% 1/2~

R: FXD COMP 1.8M 10% 1/2~
R: FXD COMP 22K OHMS 10% 1/2W
R: FXD COMP 2.2M 10% 1/2~
R: FXD COMP 27K OHMS 10% 1/2W

R: FXD COMP 270K OHMS 10% 1/2W
R: FXD COMP 2.7M 10% 1/2W
R: FXD COMP 3.3K OHMS 10% 1/2W
R: FXD COMP 33K OHMS 10% 1/2~

FXD COMP 330K OHMS

R:

5% 1/2W

10% 1/2W

01121
01121
01121
01121
01121

01121
01121

01121
01121
01121

01121
01121
01121
01121
01121

01121
01121
01121
01121
01121

01121
01121
01121
01121
01121

EB2435
EB2745
EB3325
EB3935

El34345
EB5115

EB7525
EBlOll
EB1021
EB1041

EB1051

EB1241

EB1531
EB1541
EB1551

EB1831
EB1851
EB2231
EB2251
EB2731

EB2741
EB2751
EB3321
EB3331
EB3341

11

11

10

1

2

11

1

2

1

2

12

3

1

2

2

7
6

2

11

1

2

11

11

1

2

11

1

3

11

2

5

11

11

11

1

2

1

2

#

See introduction to this section

6- 13

Section

Table 6-2

VI

Model 120B

hp Part No.

0687-3921
0687-3931
0687-471
0687-4731
0687-4741

0687- 5631
0687- 5641
0687-6831
0687- 6841
0687-8231

0687-8241
0689- 1635
0689-1835
0689-2235
0689-2435

0689- 7525
0690- 1041
0690-1841
0690-4741
0690- 5641

1

Table 6-2. Replaceable

Description

FXD COMP

R:

R: FXD COMP 39K OHMS 10% 1/2~
R: FXD COMP 470 OHMS 10% 1/2~
R: FXD COMP 47K OHMS 10% 1/2~
R: FXD COMP 470K OHMS 10% 1/2~

R: FXD COMP 56K OHMS 10% 1/2~

R: FXD COMP 560K OHMS 10% 1/2W
R: FXD COMP 68K OHMS 10% 1/2~
R: FXD COMP 680K OHMS 10% 1/2~
R: FXD COMP 82K OHMS 10% 1/2~

R: FXD COMP 820K OHMS 10% 1/2W
R: FXD COMP 16K OHMS 5% 1W

R:

FXD COMP 18K OHMS 5% 1W

R: FXD COMP 22K OHMS 5% 1W
R: FXD COMP 24K OHMS 5% 1W

R: FXD COMP 7.5K OHMS 5% 1W
R: FXD COMP lOOK OHMS 10% 1W
R: FXD COMP 180K OHMS 10% 1W
R: FXIj COMP 470K OHMS 10% 1W
R: FXD COMP 560K OHMS 10% 1W

3.9K OHMS 10% 1/2W

#

Parts

(Cont'd)

Mfr.

01121
01121
01121
01121
01121

01121
01121
01121
01121
01121

01121
01121
01121
01121
01121

01121
01121
01121
01121
01121

Mfr. Part No.

EB3921
EB3931
EB4711
EB4731
EB4741

EB5631
EB5641
EB6831
EB6841
EB8231

EB8241
GB1635
GB1835
GB2235
GB2435

GB7525
GB1041
GB1841
GB4741
GB5641

RS

TQ

1

2
11

2

5
4

1

2

1

11
11

1

3
2

1

11

11

11

11

2

1

2

1

11

1

3

11

11

11

0690-8221
0690- 8231
0692-3635
0693-1031
0693-1 541

0693-1831
0693-5651
0693-8251
0699-0006
0727-0055

0727- 0060
0727-0100
0727-0110
0727-0132
0727-0157

0727-0173
0727-0197
0727- 0201
0727-0202
0727-0208

0727-0218
0727-0221
0727-0235
0727-0246
0727-0261

R: FXD COMP 8.2K OHMS 10% 1W

R: FXD COMP 82K OHMS 10%

R: FXD COMP 36K OHMS 5% 2W

R: FXD COMP 10K OHMS 10% 2W

R: FXD COMP 150K OHMS 10% 2W

R: FXD COMP 18K OHMS 10% 2W

R: FXD COMP 5.6M 10% 2W

R: FXD COMP 8.2M 10% 2W
R: FXD COMP 4.7 OHMS 10% 1W

R: FXD DEPC 201 OHMS

R:

FXD DEPC 225 OHMS
R: FXD DEPC 1K OHMS
R: FXD DEPC 1.5K OHMS
R: FXD DEPC 4K OHMS
R: FXD DEPC 10K OHMS

R: FXD DEPC 20K OHMS
R: FXD DEPC 59.48K OHMS
R: F.XD DEPC 71.56K OHMS
R: FXD DEPC 83K OHMS
R: FXD DEPC lOOK OHMS

R:

FXD DEPC 180K OHMS
R: FXD DEPC 200K OHMS
R: FXD DEPC 360K OHMS
R: FXD DEPC 600K OHMS
R: FXD DEPC 900K OHMS

1%

1/2~

1%

1/2~

1%

1/2~

1%

1%

1/2~

1%

1/2~

1%

1/2~

1%
1%

1%

1/2~

1%

1%

1%

1%

1%
1%

'ow

1/2~

1/2~

1/2W
1/2~
1/2~

1/2~
1/2~
1/2W
1/2W

01121
01121
01121
01121
01121

01121
01121
01121
01121

hp
hp

hp
hp
hP
hp

hp
hp
hP
hp
hP

hp
hp
hp
hP
hp

GB8221
GB8231
HB3635
HB1031
HB1541

HB1831
HB5651
HB8251
GB47G1

2

1

11
2

1

11

11
11

1

3

1

3
2

1

11
11

1

2

11

11

11

11

1

2

11
11
11

11
11
11
11
11

#

See introduction to this section

01260-2

Model 120B

Section VI

Table 6-2

hp

Part No.

0727-0271
0727- 0274
0727-0285
0727-0287
0727-0289

0727- 0292

0727-0376
0727-0378
0730-0024
0730- 0056

0730- 0062
0761- 0077
0767-0010
0771-0006
1200-0041

1200-0053
1200- 0062
1450-0048
1850-0038
1854-0015

Table 6-2. Replaceable

Description

FXD DEPC

R:

FXD DEPC

R:

FXD DEPC

R:
R: FXD DEPC 2M

990K OHMS

1M

1%

1.8M

1%

1%

R: FXD DEPC 2.52M
R: FXD DEPC 3M

R: FXD DEPC 1.98M

1%

1/2~

1%

R: FXD DEPC 257.1K OHMS
R: FXD DEPC 7.5K OHMS
R: FXD DEPC 68.38K OHMS

R: FXD DEPC 80K OHMS

#

1%

1/2~

1/2~

1/2~

1%

1/2~

1/2~

1%

1%

1%

1%

1W

1/2~

1/2~

1W

1W

R: FXD METFLM 24K OHMS 5% 1W
R: FXD MET OX 15K OHMS 5% 3W
R: FXD MET OX 27K OHMS 10% 4W
SOCKET: TRANSISTOR

SOCKET: TUBE 7 PIN MINAT
SOCKET: TUBE 9 PIN MINAT

LAMP: INDICATOR
TRANSISTOR:

2N301

TRANSISTOR: SILICON NPN

Parts

(Cont'd)

Mfr.

hp
hp
hp

71785
71785

71785
08717
86684

hp

hP
hP
hP
hP
hp

hp
hP
hp
hp
hp

hP

Mfr.

Part

133-92-10-034
111-51-11-069

121-51-11-060
858-R
2N301

No.

9

RS

TQ

11

1

3

11

11
11

4

1

11

11

11

2

1

11
10
11

11

11

4

1

1

13

11

11
10

1901-0030
1901- 0044
1901-0045
1902-0225
1920-0001

1921-0005
1921-0010
1923-0018

1923-0021

1932-0022

1932-0029
1933-0004
1940-0001
2100-0054
2100-0093

2100-0094
2100-0095
2100-0096
2100-0102
2100-0105

2100-0144
2100-0150
2100-0154
2100-01?3
2100-0174

DIODE: SILICON 800V

PIV
DIODE: SILICON
DIODE: SILICON

DIODE: SILICON AVALANCHE

18.7V

TUBE: ELECTRON 5642
TUBE: ELECTRON 6C4

TUBE: ELECTRON

12B4A
TUBE: ELECTRON 6AQ5
TUBE: ELECTRON 6AU6

TUBE: ELECTRON 6DJ8
TUBE: ELECTRON 12AU7

TUBE: ELECTRON 6U8
TUBE: ELECTRON 5651
R: VAR

WW

LIN 500 OHMS 10% 2W

R: VAR COMP LIN 20K OHMS 20% 1/4~
R: VAR COMP LIN 50K OHMS 3% 1/4~

R: VAR COMP LIN lOOK OHMS 30% 1/4~
R: VAR COMP LIN 1M 30% 1/4~
R: VAR COMP LIN 500K OHMS 30% 1/5~
R: VAR COMP LIN 3.5M 30% 1/2~

R: VAR COMP 250K OHMS 30% 1/4~
R: VAR COMP DUAL TANDEM 10K OHMS 20%

R: COMP LIN 1K OHMS 30°/0 3/10~

R: VAR COMP LIN 200K OHMS 20% 1/4~
R: VAR COMP 500K OHMS 20%, 5% CW LOG

TAPER

1/4~ W/SPST SWITCH

02735

hp
hp

hP

82219
86684

33173
82219
33173
13396

33173
33173
86684
11237
11237

11237
11237
11237
11237
12697

11237
11237
11237
11237

11237

OBD#

5642
6C4

12B4A
6AQ5
6AU6
6DJ8

12AU7

6U8

5651

252

OBD#

OBD#
UPE 70 SPECIAL

OBD#
UPE 70 SPECIAL
UPE 70 SPECIAL
OBD#

UPE 70
UPE 70
UPE 70

VF-45

RGC-45

3

3
11

11
11

2

2

11

2

2
11

11

3

3

5

5

3

3

11

11

11

2

1

11

11

1

2

11

1

2

11

11

11
11

--

-

#

See introduction to

this

-

--

section

-

6-15

Section VI
Table 6-2

Model 120B

hp Part No.

+

Table 6-2. Replaceable

r-

R: VAR COMP LIN 3.3K OHMS 10% 1/3~
R: VAR COMP LIN 200K OHMS 20% 1/4~
R: VAR COMP DUAL TANDEM LIN 1M 20%

1/4w

R: VAR COMP LOG 2 SECT lOOK OHMS/SECT

20% 1/4W

R: VAR COMP LOG 2 SECT lOOK OHMS/SECT

20% 1/4W

R: VAR COMP LIN 300 OHMS 20% 3W
FUSE: CARTRIDGE 1.6 AMP S-B (for 115V

OPERATION)

FUSE:
SWITCH: ROT SPDT

SWITCH: ROT 4 SECT 18 POS
SWITCH: PUSH DPDT

SWITCH: S WE
COVER:
BRACKET: LEFT RACK MOUNT
BRACKET: RIGHT RACK MOUNT

STRIP: LARGE FILLER
INDUCTOR: ALIGNMENT
ASSY: LEFT CONNECTOR
BINDING POST: BLACK (SHARED BY

BINDING POST: RED (1USED)

CARTFUDGE 0.8 AMP S-B (for 230V

OPERATION)

SIDE

AND 5301)

Description

1

SECT 4 POS

#

Parts

JlOl

(Cont'd)

I

Mfr.

I

Mfr.PartN0.

UPE 70

VF-45

TYPE H

FRAME: ASSY SIDE
COVER: BOTTOM

MSY: FULL MODULE FOOT
TUBE: NEON GLOW
TUBE: NEON GLOW

CRT: P2 PHOSPHOR INTERNAL GRATICULE

CRT: P7 PHOSPHOR INTERNAL GRATICULE

CRT:

CRT: P31 PHOSPHOR INTERNAL GRATICULE

CORD: POWER

PI1

PHOSPHOR ALUMINIZED INTERNAI

GRATICULE

TRANSFORMER: POWER
INDUCTOR: FXD RF 500
INDUCTOR: FXD RF 100

ph

ph

10%

9941/PH-

CS-

151/7.5 ft.

#

See introduction to this section

01 2 60- 2

Section

Table 6-3

VI

Model 120B

81349 Mll!hv Spcclticatlm
81415 11Ikw Prod~cb. Inc. Clevehnd. Ohlo
81453 Raytheon MIg. Co.. lndustlial Components

Dvr.. lnduslf. Tuk Openllms Newton. Mass.
81483 lnletnal#onrl Rect!ftct Corp. El Segunda, Catd.
81541 The Alrplx Puoducts Co. Cambftdge, Mass.
81860 Berry Controls. Inc. Wateflwn. Mass.
82042 Carter

Parts Co. Skok~e.

82142 Jetttrs EIect1on1cs DIVISIO~ 01

Spcet Carbm Co.

Alla B. DuVont Labs. Inc. Cl~tton. N.J.

82110
82209 Magulie lnduslltes. Inc. Bmwlch, Conn.
82219

Sylvan. Elect~~c Plod. Inc.

Elctrmtr Tube Olr. Enponun. Pa.

Astron Co. East Newarh, N.J.

82316
82389

Sw~lchclall. lnc. Chouto.

82641 Mebls and Controls. Inc.. Dlr.

Teaas Instlumenb. Inc..

Swnce~ Puods. Atllebwo. Mass.
82866 Research Ploducts Cwp. Mad#sm, Wis.
82811 Rotron Manulacturmg Co.. Inc. Wwdslrk. N.Y.

VecIw EIecl~on~c Co. Gtendale.

82893
83053 Waleln Washer Yfi. Co. La Anslss. CaIlI.
81058 Carl Fastanel Co. Cambr~dge, Mass.

New

Hampshire

83086

83125 Fy~anod Electric Co. Darlln~ta. S.C.
83148 Eleclro Cuds CO. Lor Angeles, Calit.
83186 V~CIOIY Engtnuring Corp. Sprlngfleld. N. J.
83298

Bendbz Cap.. Red Benk 00". Red Bank. N.J.
83315 Hubbelt Cwp. Mundebm.
83330 Snllh. Herman H.. lac. Brooklyn. N.Y.

Cenlnl Scaw Co. Ch~cato,

83385

83501 Gavlll Wlre ad Cable Co..
83594

Bullwghs Cwp..
83140

Eveready BaHew New Yolk. N.Y.
83111

Yodel Eng. and Mlg.. Inc. Huntintlm.
83821 Lqd Scruggs Co. Feslus. Yo.
84111

Arc0 Electtonls. Inc. Nn York. N.Y.

1.1. Glrrmrr Co.. Inc.

-843%
84411 Good All Eleclric Ytg. Co. Ogallala. Neb.
84910

Lrkas Tarzlan. Inc. Bloom~ngton. Ind.

85454

Boonlm Yoldlnt Commny Boontm. N.J.
A.B. Boyd Co. Ln Fnnc~sco. Calif.

85471

Btll Bearing. lnc.

Oar. of Anesce Cwo.
Electm!~ Tube DIV. Phlntield, N.J.

Du Bois, Pa.

o(

Peteibwough. N.H.

Booktsld. Mass.

Sm

Francisco. CaIlI.

. . . . . . .

Qlil.

Ind.

Table 6-3. Code List of

W.

W..

Y~vhrwm

85414 R.M. Bncamah 6 Co. Ln Ffanclsco. Calit.

.

Ill.

Ill.

Ill.

Ill.

Kolled Kwds. Inc. New Haven. Conn.

85660
85911 Snnkss Rvbbel Co. Chlcato,
86191

Clifton

Preclslon Products Cllllon Helghk. Pa.

Prerlrlon Rubber Plod~tB Corp. Dayton. Ohlo

86519
86684 Radlo Colp. of Ameflca.. RCA

Eleclron Tuk Ow. Harrison. N.J.

81216 Philco
81413
81664 Van Wahrs 6 Rqm
84140 CutlerHamnr. Inc. Ltncoln.

88220 Gould.Nal~onal Bettelies, Inc. St. Paul. Mmn.
89231

89473 General
89636
m665 Unlhd Tnnshner Co. Chlugo.

90119 U.S. Rubkr Co.. Mechanical
Oo10 Bor#ng Engimerlnt Co. Pn Francisco. Calof.

91260 Connol Spllng Mtg. CO. Pn Fnrlsco. Callf.
91345 Mlliel 0111 6 Nameplab CO. El Monte, Calil.
91418
91506 Augt B~olhers'. Inc. AlICbo10. MISS.
91631
91662 Elco Cup. R~ladelohia. Pa.
91131
91821 K F Oealopnenl Co. Redrod Clh. Callt.
91929 Mlnaeapolts-Hamywell Rezuhtor Co..

91961 Nahm-Bror. Splng Co. Oakland, Qtff.
92180 Tlu.Conneclu Corp. Peabody. Mass.
921%
92361 Elgrel Opllcal CO.. Im. Rrhertrr. N.Y.
97601 T~nsol~te Insubled Wlre Co. Taruytan. N.Y.
93332

93369 Robblnr and Myers. Inc.
93410
93188 Howard J.

Cwporatlm (Lansdale

Olrfslon) Lansdale. PI.

Wesleln Fldrous Ghss Producb Co.

81930 Tower Ute. Corp Providence. R.

88698 Genefa1

Glaybar Elertl~c Co. Oakland. Cal~t.

89462 Waldar Kohtnoov. lnc. Caabrbdge. Mass.

Carter Parts Dir. 01 EconMy Bak~ Co.

Goods Ow. Pasuic. N.J.

Radio

Matellall CO. Ch~cago,

Dale Electron~cr. Inc. Cot~mb~s, Neb,.

Gremal MI#. Co.. Im. ~akelleld, mss.

M~croswllch Dlr. Ftmpotl.

Un~velsal Mehl Plod.. lnc. Bsssell Puenle. Calot.

Sylvanla Eleclllc Plod. Inc..

Sem~cmductu Ow. Woburn. Mass.

Stevens Mfg. Co.. Inc. Mansfield. Ohio

I*.

Mills,

lnc. Butlalo, N. Y.

Electric

Oisbobulin: Corp.

Smllh lnc. PoltMonmouh.

Ill.

Pn Fnnctsco. Qld.

Seattle, Wash.

Ill.

Schcneclady. N.Y.

Chicato,

Ill.

Ill.

Ill.

Ill.

-bw

Ywh. N.Y.

I.

J.

Manufacturers (Cont'd)

93929

G.

V.

Conllols L~v!ngston, N. J.

Insulme-Van Nwman Ind., Inc.

93983

EIec110n1c OIVISIWI Ylnchestef, N.H.
MI31 General Cable Cofp. Baymm. N.J.
94144 Raylhem Mfe. Co.. Industr~al Conwnenk

OIV.. Rece~vlne Tube Opesl~on Qunnq. Mass.
94145

Raythem YIg. CO.. ICm~cmd~cIw

.

Cal~fotn~a Slrnt Plant Newlon. Ylss.

94148 L~enl~l~t
94154 TunpSol Elech~c. Inc. Newatk, N.J.

94191

I.

94222 Soulhco Ow. 01 S. Cheshr Corp. Lester. Pa.
94310

94330
94682 Wwcestel Pressed Alun~nvn Cap.

95023 Phllblck Reseaich.fs, lnc.
95236 AI11es Plodurb Cofp.
95238 Cntlmnhl Connectol Cwp.
95263 Leecraft Ytg. Co.. Inc.
95264 Lsco Electra~cs. Inc.
95265 Nat~onal Coll Co.
95215
95348 Gordas Cap.
95354 Melhde Mft. Co.
95112
95981 Weckesse~ CO.
96061 Hugglns Labwalwns
%W5 HIQ D~vls~m ol Aeraon
96256 ThordatsmYe~smer 01". of

%Z96

96330 Callton
96341 Mlcroware Assruhs. Inc.
96501 Excel
91464
91539

91%6 CBS Elecbonics.
91919 Rem Restslw Cwp.

9.3141 Axel Lothers Inc.
98159 Rubber Tech. Inc.

Radio

Ptoducts.

Curllsslrlght Corp.,

Eleclrm~cs Dnr. East Patarson, N.J.

Tlu Ohm Plod. Ow. of Model

Eng~ncering and Mfg. Co.

Wile

Cloth Plducts Inc. Chicago.

V#tramon. Inc.

Oage Elecl!~c CO . Inc

Maguue lndusb~es, tnc.

Sob!

Mrnutacturlng Co.

Law

Co

trans lor me^

lndustual Relaanlng Rvnt Co
Aulomatlc and Prer~s~m Yfg

Co.

Dlv. ot C.B.S.. lnc.

01v..

IIC.

Loveland. Colo.

Worcester, MISS.

Baton. Mass.

IOOdSld*,

New Ywk. N.Y.

Butbnk. Callf.

Sheodan. Iyo.

Brldgepoll. Conn.

Bloonfbeld. N.J.

Ch~cato,

Flankl~n. Ind.

Ch~ogo.

lunnyvals. 0111.

Ml. Ca~mel,

LOS Ayeb.

C~ICIIO.

Burlingtm. Mass.

Lbkbnd. 0111.

lrv~nglon. N. J.

co.

Yonkers. N.Y.

Danven. Mass.

Yonkers. N.V.
Jama~ca. N.Y.

Lrdena, Calif.

Chicago.

nuant, Fla.

n.r.

Olean. N.Y.

0lil.

98220 Fnncls L. Yalq
98218 Ylc~odd. Inc.
98291 Isalect~o Colp. Mamaroneck. N Y.

Camd Cwp. Redwood Clh.

98405
98131 General Mllls M~nneapol~s. Ylnn.
98821 Nwth

Hills

Elecb~c Co. Mbneola. N.Y.

Clrrtlr Trans~slot Plod

98925

Dlv. ol Clevlle CWP

98918

lnblnatowl Elecbnlc

Resea~ch Cwp Burbmk. 0111.
BID) Colunb~a Technlul Cwp. New Yak, N.Y.
99313 Varlan Ass~lales Pal0 Allo. 0111.
99515 Marshall Industras. Elecbm

Produtlr Dlrts~on Paudenr. 0111.
99701 Calrol Srltch Dlrl~lM. Cmbols Co.

Ill.

Ill.

Ill.

Ill.

Ill.

Ill.

ot Amarxa El L~undo. 0ld.
99800 hkran Electron~cs Cwp. East Aurwa. I.V.
99848

WIICO Cwpo~l~on lndlanawlts, lad.
99934 Rmbnndl. tnc. Balm. Mass.
99942

Hotlman Lm~con4etw DIV.

Hoffman EbcI~on~s CWP. Evamlm.

99951 Technoiqy Insbumcnl Cwp

01 Caltl.

THE FOLLOWING H-P VENDORS HAVE NO NU&
BER ASSIGNED IN THE LATEST SUPPLEMENT TO
THE FEDERAL SUPPLY CODE FOR MANUFAC
TURERS HANDBWK.

JOWD Windestel Elecbonics. Inc,
WWF Malco Tool and 010 Los Ayelm, Calit.

WOW hsbm Coll Div. of Auloulic

Ind.. Inc. Redwood Clh.

WWP Ty-Cat MI:. Co.. Inc. Hollistm. Mass.

MOO2

Wllla Luher Rodrls Cup. Newark, N.J.
WMA bitnsh Radlo Ekclrm#cs Ltd. Wash~ngla. D.C.
WOAB ETA Enlbd
WMC Indlana Gemnl Cwp.. Elect. Div. Indiana
WOBB Prrc~r~m Inslruncnl Cnpmnts Co.

WOYM Rubber EUI.
OOONN A
OOWQ Coollrm O~kland. CaItf.
OOOSS Cntlot 01 Eltin lllch Co. Burbnk. Calif.
WDIW Calllomr Bste~n bb. Burt~ngame. Cald.
WY S.K.

6

"N"

D Manubctulong Co.

Inla

Co.

Dewlopent

La

Awk 45, C~III.

So.

ol

IqW

Rsadenr. CsIoI.
Pasadel. QI$t.

QIII.

1alth.n. Mass.

Ill.

Park.

Calif.

Lnb Monoo. Cal#t.

Qlil.

Van

Iws, Calil.

Hayward, Calil.

SU

Jmt 21.

Qlil.

~m:

FSC. HmW

114-1

Dated

H4-2

0.W

awlmnk

DECEMBER
MARCH

1962,

1W

01260-2

Model 120B

Appendix I

APPENDIX

MANUAL CHANGES

This appendix contains information on changes re-

quired to adapt this manual to an instrument with a
serialprefix listed in the table below. Check for your
instrument serial prefix and make the changes indica-

ted. Note that these changes adapt the manual to cover
a particular instrument
willnot apply to an instrument subsequently modified
in the field.
errata in this manual and on any other instrument
serial prefix not covered in this appendix.

Instrument

Serial Prefix

433­421­327-, 403-, 409-

303­242-, 247­202-, 217-, 219-, 223-

Tables 6-1 and 6-2,

~322A/~: Change to hp Part No. 0180-0127; C:

fxd, elect 2-sect, 120 x 40
3OOVDCW; Mfr 56289; Mfr Part No. D36235.

Tables 6-1 and 6-2,

Al: Change to hp Part No. 120B-65A.
A202:
CR305: Change to hp Part No. 1902-0759; Mfr

04713; Mfr Part No.

Page 5-17, Figure 5-8,

R207:

Page 5-18, Figure 5-9,

R351:

Tables 6-1 and 6-2,

R207: Change to hp Part No. 0687-1031; R: fxd,

cornp, 10K ohms, 10% 1/2~; Mfr 01121; Mfr
Part No.

R351: Change to hp Part No. 0727-0286; R: fxd,

depc

Tables 6-1 and 6-2,

CR201: Change to hp Part No. 1901-0034; Diode:

Si; Mfr 07933; Mfr Part No.

Refer to Section

Change to hp Part No. 120B-65B.

Change value to 18K ohms.

Change value to 1.88M ohms.

EB1031.

1.88M ohms,

as

manufactured and therefore

CHANGE

CHANGE

1N2983B.

CHANGE

1%

1/2~; Mfr hp.

CHANGE

I

for information on

Make Numbered

Changes

1

1,

2

1,

2, 3

1,

2, 3, 4
2, 3, 4, 5
2, 3, 4, 5, 6

1

M,

-10% +50%

2

3

4

DW204A.

1

CHANGE

Tables 6-1 and 6-2,

A201: Change to hp Part No. 120B-19C.

C321:

C325A/~: Change to hp Partko. 0180-0030; C: fxd,

MISCELLANEOUS,

Change to hp Part No. 0180-0042: C: fxd.

120

elect,
No. D3253.

elect, 2-sect, 120x40
Mfr Part No.

Knob: TRIGGER SOURCE selector: Change to

hp Part No. 0370-0099.

Knob: TRIGGER

Part No. 0370-0134.

pf, ~~OVDCW; Mfr 56289;

D32352.

LEVELcontrol: Change to hp

CHANGE

Page 5-19, Figure 5-10,

C305, C307: Change value to 6800 pf.
C308: Relocate into A302 in parallel with T301

pin 5 and plate of

1500

~f.

C310: ~elddate into A302 in parallel with T301

pin 9 and plate of

1500 pf.
C312: Change value to .015
C313, C314: Delete.
R313: Change value to 680K ohms.
R322: Change value to 47K ohms.
R327: Change value to 1.5M ohms.

Tables 6-1 and 6-2,

A301: Change to hp Part No. 120B-65C.

A302: Change to hp Part No. 120B-llA.

C305, C307: Change to hp Part No.

C: fxd, paper, 6800 pf, 20%
56289; Mfr Part No.

C308, C310:

C: fxd, paper, 1500 pf, 20%
56289; Mfr Part No.

C312: Change to hp Part No. 0160-0062; C: fxd,

paper,

Part No.
C313, C314: Delete.
CR304: Change to hp Part No. 1901-0026; Diode:

Si; Mfr hp.

R313: Change to hp Part No. 0687-6841; R: fxd,

cornp, 680K ohms,
Part No.

R322: Change to hp Part No. 0687-4731; R: fxd,

cornp, 47K ohms,
Part No.

R327: Change to hp Part No. 0687-1551; R: fxd,

cornp,
Part No.

Change to hp Part No. 0160-0061;

.015 pf,

184P153930.

EB6841.

EB4731.

1.5M ohms, 10% 1/2~; Mfr 01121; Mfr
EB1551.

V303, and change value to

V304, and change value to

1O0h

3000VDCW; Mfr 56289; Mfr

10% 1/2~; Mfr 01121; Mfr

5

Mfr

rd,

450VDCW; Mfr 56289;

6

pf.

0160-0110;

3000VDCW; Mfr

184P682030.

5OOVDCW; Mfr

184P152050.

10% 1/2~; Mfr 01121; Mfr

pait

CATHODE RAY TUBE WARRANTY

The cathode ray tube (CRT) supplief in your Hewlett-Packard
Oscilloscope and replacement
guaranteed by the Hewlett-Packard Company against electri­cal failure for a period of one year from the date of sale.

Broken tubes or tubes with burned phosphor are not included
under this guarantee.
claim should be made with the responsible carrier.

If

CRTs purchased from @ are

the CRT is broken when received, a

Your nearest Hewlett- Packard
a stock of replacement tubes

processing the warranty claim.

In order to ensure credit for a CRT under the warranty period,
the reverse side of this sheet shouldbefilledout completely

and returned with the defective tube. To avoid

tube while in shipment, carefully follow the shipping instruc-

tions listed below; credit is not allowed on broken tubes.

SHIPPING INSTRUCTIONS

1. Carefully wrap the tube in 1/4 inch thick
cotton batting or other soft padding material.

Wrap the above in heavy kraft paper.

2.

3.

Pack wrapped tube in a rigid container which
is at least 4 inches larger than the

each dimension.

Surroundthe tube

4.

packedexcelsior or similar shockabsorbing
material; be sure the packing is tight all around
the tube.
Tubes returned from outside the continental

5.

United States should be packed inawooden box.
Ship prepaid by AIR FREIGHT or RAILWAY

6.

EXPFUISS to:

Hewlett- Packard Company
CRT Manufacturing Dept.

1900 Garden of the Gods Road

Colorado Springs, Colorado 80907

Atten: CRT Quality Assurance

Sales,'Service Office maintains

and,if desired, will assist in

damage to the

tube

in

withat least four inches of

CRT WARRANTY CLAIM

FROM: Date

NAME

COMPANY

ADDRESS

For additional information, contact:

NAME
TITLE
COMPANY

ADDRESS

1.

@

INSTRUMENT a) MODEL

b) SERIAL NO.

2.

CRT a) TYPE (on bulb)

b) SERIAL NO. (on CRT base)

-

-

-

@

-

-

I
I

I

I

I

I

I

I

I

I

I

I

I

I

I
I

I
I

I
I

I

I

I
I

I

I

I

I
I

I
I

I

I
I

I

I

I

I

I

lu'

5

I

4

I

$

kI

a

I

Q

1

==I

2:

;

I

u;

02537-3

3.

Is defective tube original. YES NO

4.

Date purchased

5.

Describe nature and/or symptoms of trouble.

6.

Describe operating conditions prior to and at time of failure.

(Please estimate CRT "on-time" since purchase.

(if

available)

)

I
I
I

I

I

I

I

j

I

I

I
I

I

I

I
I

I

I

I

I

I

I

I

HP

SALES AND SERVICE OFFICES IN THE U.S. AND CANADA

ALABAMA

Huntsville. 35801
Hewlett-Packard
Southern Sales Division
Holiday Office Ctr., Suite 18
[phone]

TWX: 510-579-2204

ARIZONA

Scottsdale, 85251

Hewlett-Packard

Neely Sales Oivision

3009 No. Scottsdale Rd.
[phone]

TWX: 602-949-0111
Tucson. 85716

Hewlett-Packard
Neely Sales Division
232 So. Tucson Blvd.
[phone]

TWX: 602-792-2759

CALIFORNIA

Los Angeles Area
Hewlett-Packard
Neely Sales Division
3939 Lankershim Blvd.
North Hollywood 91604
[phone] and 766-3811

TWX: 910-499-2170

Sacramento, 95821
Hewlett-Packard
Neely Sales Oivision

2591 Carlsbad Ave.

[phone]

TWX: 916-444-8683

San

Diego, 92106
Hewlett-Packard
Neelv Sales Division
1055 Shafter Street
[phone]

TWX-714-276-4263

San Francisco Area
Hewlett-Packard
Neely Sales Division

1101 Embarcadero Rd.
Palo Alto

[phone]

TWX: 910-373-1280

COLORADO

Englewood,
Hewlett.Packard
Neely Sales Division
7965 East Prentice
[phone]

TWX: 303-771-3056

CONNECTICUT

Middletown, 06458
Hewlett-Packard

Yewell Sales Division

589
(203) 346-661 1

TWX: 710-428-2036

FLORIDA

Miami. 33125
Hewlett-Packard
Florida Sales Division
2907 Northwest 7th St.
[phone]

Orlando, 32803
Hewlett-Packard
Florida Sales Division
621 Commonwealth Ave.
[phone]

TWX: 305-275-1234

St. Petersburg, 33708

Hewlett-Packard
Florida Sales Division

410-150th Ave., Madeira Beach

[phone]

TWX: 813-391-0666

94303

801 10

Saybrook Rd.

GEORGIA

Atlanta, 30305
Hewlett-Packard
Southern Sales Division
3110 Maple Drive, N.
[phone]

TWX: 810.751-3283

ILLINOIS

Chicago, 60645
Hewlett-Packard

Crossley Sales Division

2501 West Peterson Ave.

(31 2) 275-1600

TWX: 910-221-0277

INDIANA

Indianapolis, 46205
Hewlett-Packard

Crossley Sales Oivision
3919 Meadows Dr.
[phone]

TWX: 317-635-4300

KENTUCKY

Louisville. 40218

Hewlett-Packard

Southern Sales Division
Sulte 4, 3411 Bardstown Rd.

[phone]

TWX: 810-535-3128

MARYLAND

Balt~more, 21207
Hewlett-Packard

Horman Sales Division

6660 Security Blvd.

[phone]
Washington, D. C. Area

Hewlett-Packard

Horman Sales Division
941

Rollins Avenue
Rockville 20852
[phone]

TWX: 710-828-9684

MASSACHUSElTS

Boston Area

Hewlett-Packard
Yewell Sales Division
Middlesex Turnpike
Burlington 01804
[phone]

TWX: 710-332-0382

MICHIGAN

Detroit, 48235

Hewlett-Packard

Crossley Sales Division

14425 West Eight Mile Road

[phone]

TWX: 313-342-0702

MINNESOTA

St.

Paul, 55114
Hewlett-Packard
Crossley Sales Division
842 Raymond Avenue
[phone]
TWX: 910-563-3734

MISSOURI

Kansas City, 64131
Harris-Hanson Company
7916 Paseo Street
[phone]

TWX: 816-556-2423

St. Louis, 63144

Harris-Hanson Company
2814 South Brentwood Blvd.
[phone]

TWX: 314-962-3933

NEW JERSEY

Asbury Park Area

Hewlett-Packard

Robinson Sales Oivision
Shrewsbury

[phone]

E.

Englewood, 07631
Hewlett-Packard
RMC Sales Division
391 Grand Avenue

[phone]

NEW MEXICO

Albuquerque. 87108

HewletbPackard
Neely Sales Division

Lomas Blvd., N.

6501
[phone]

TWX: 910-989-1665

Cruces, 88001

Las
Hewlett.Packard
Neely Sales Division
114 S. Water Street

[phone]

TWX: 505-524-2671

NEW YORK

New

York, 10021
Hewlett-Packard
RMC Sales Division
236 East 75th Street
[phone]

TWX: 710-581-4376

Rochester, 14625
Hewlett-Packard

Syracuse Sales Division
800 Linden Avenue
[phone]

TWX: 716-221-1514

Poughkeepsie, 12601
Hewlett-Packard
Syracuse Sales Division
82 Washington St.

[phone]
TWX: 914-452-7425

Syracuse, 1321 1
Hewlett-Packard
Syracuse Sales Division
5858 East
(3 15) 454-2486
TWX: 710-541-0482

NORTH CAROLINA

High Point, 27262

Hewlett-Packard
Southern Sales Division
1923 N. Main Street

[phone]

TWX: 510-926-1516

OHIO

Cleveland. 44129
Hewlett-Packard
Crossley Sales Division
5579 Pearl Road
[phone]

TWX: 216-888-0715

Dayton. 45409
Hewlett-Packard

Crossley Sales Division

1250 W. Dorothy Lane

[phone]

TWX: 513-944-0090

PENNSYLVANIA

Camp Hill
Hewlett-Packard
Robinson Sales Division
[phone]

Philadelphia Area
Hewlett-Packard
Robinson Sales Division
144 Elizabeth Street

West Conshohocken 19428

[phone] and 828-6200

TWX: 215-828-3847

Molloy Rd.

E.

Pittsburgh Area

Hewlett-Packard
Crossley Sales Division
2545 Moss Side Blvd.

Monroeville 15146

[phone]

TWX: 710-797-3650

TEXAS

Dallas, 75209
Hewlett-Packard
Southwest Sales Division
P.O. Box 7166, 3605 lnwood Rd.
[phone] and 332-6667

TWX: 910-861-4081

Houston, 77027
Hewlett-Packard
Southwest Sales Division
P.O. Box 22813, 4242 Richmond Ave.

[phone]

TWX: 713-571-1353

UTAH

Salt Lake City, 84115

Hewlett-Packard
Neely Sales Division
1482 Major St.
[phone]

TWX: 801-521-2604

VIRGINIA

Richmond,.23230

Hewlett-Packard
Southern Sales
2112 Spencer Road

[phone]
TWX: 710-956-0157

WASHINGTON

Seattle Area

Hewlett-Packard

Neely Sales Oivision
11656 N. E. 8th St.

Bellevue 98004
[phone]

TWX: 910-443-2303

CANADA

Montreal, Quebec

Hewlett-Packard (Canada) Ltd.

Mayrand Street

8270

[phone]

TWX: 610-421-3484

Ottawa, Ontario

Hewlett-Packard (Canada) Ltd.

1762

Carling Avenue

(613) 7224223

TWX: 610-562-1952

Toronto, Ontario

Hewlett-Packard (Canada) Ltd.

1415 Lawrence Avenue West

[phone]

TWX: 610-492-2382

GOVERNMENT
CONTRACTING OFFICES

Middletown, Pa. 17057
Hewlett-Packard
Contract Marketing Division
Olmsted Plaza
[phone]
TWX: 717-760-4816

West Conshohocken, Pa. 19428

Hewlett-Packard

Contract Marketing Division

144 Elizabeth St.
[phone]
TWX: 215-820-3847

Division

HP

INTERNATIONAL SALES AND SERVICE OFFICES

ARGENTINA

Mauricio A.

Telecomunicaciones

Carlos Calvo 224, Buenos Aires
Tel: 30-6312

AUSTRALIA

Sample Electronics

9-11 Cremorne Street

Richmond E. 1, Victoria

Tel: 42-4757 (3 lines)

Sample Electronics

4 Grose Street, Glebe, N.S.W.
Tel: 69-6338 (6 lines)

AUSTRIA

UNILABOR H.m.b.H.
Wissenschaftliche lnstrumente

Rummelhardtgasse 6/3
P.O. Box 33, Vienna
Tel: 42 61 81

BELGIUM

Hewlett-Packard Benelux
20-24 Rue de I'Hopital, Brussels 1
Tel: 11.22.20

BRAZIL

CIENTAL IMPORTACAO E COMERCIO LTDA

R. Cons. Crisoiniano. 69.8. Coni. 81
Sao Paulo,
Tel: 324332

CANADA

Hewlett-Packard (Canada) Ltd.
8270

Montreal,
[phone]

Hewlett-Packard (Canada)

1762 Carling Avenue
Ottawa, Ontario
[phone]

Hewlett-Packard (Canada) Ltd.

1415 Lawrence Avenue
Toronto, Ontario
[phone]

CHILE

Hector
Casilla 13942, Santiago
Tel: 6.42.26

DENMARK

Tage
Ronnegade
Tel: 29.48.00

FINLAND

INTO
P. 0. Box 153
11

Tel: 6.11.33

FRANCE

Hewlett-Packard France
150
Tel: [phone]

GERMANY

Hewlett-Packard
Steindamm 35, Hamburg
Tel: 24.05.51

Hewlett-Packard
Kurhessenstrasse 95

6 Frankfurt am Main

Tel: 52.00.36

Saurez

(Vic.) Pty. Ltd.

(N.S.W.) Pty. Ltd.

IX/71

.

S:P.

Mayrand Street

Quebec

.

Ltd.

W.

Calcagni

Olsen A/S

1,

Copenhagen

O/Y

Meritullinkatu, Helsinki

Blvd. Massena, Paris 13e

fl

V.m.b.H.

V.m.b.H.

Hewlett-Packard
Reginfriedstrasse 13

8 Munich 9

Tel: [phone]
Hewlett-Packard V.m.b.H.

Technisches Biro
Herrenbergerstrasse 110
703 Boblingen, Wurttemberg

Tel: 6971

GREECE

K. Karayannis
Klaftmonos Square, Athens 124
Tel: 230.301 (5 lines)

INDIA

The Scientific lnstrument Company, Ld.
6,

Tej Bahadur Sapru Road, Allahabad

Tel: 2451
The Scientific lnstrument Company, Ld.

240, Or. Dadabhai
Tel: 26-2642

The Scientific lnstrument Company, Ld.

11, Esplanade East, Calcutta

Tel: 23-4129
The Scientific lnstrument Company, Ld.

30, Mount Road, Madras 2
Tel: 86339

The Scientific lnstrument Company, Ld.

8-7, Ajmeri Gate Extn., New Delhi

Tel: 271053

IRAN

Telecom Ltd.
P.

0. Box 1812, Tehran

Tel: 43850

ISRAEL

Electronics

16 Kremenetski St., Tel Aviv

Tel: [phone]

ITALY

Hewlett-Packard ltaliana
Viale Lunigiana 46, Milan
Tel: [phone]

Hewlett-Packard ltaliana S.p.A.
Palazzo ltalia
Piazza Marconi, 25, Roma-Eur
Tel: [phone]

JAPAN

Yokogawa-Hewlett-Packard

2270

Ishikawa-cho
Hachioji, Tokyo
Tel: Hachioji 0426-3-1231 (19 lines)

Yokogawa-Hewlett-Packard

No. 3, 6-chome, Aoyama-Kitamachi
Akasaka. Minato-ku, Tokyo
Tel: [phone]

Yokogawa-Hewlett-Packard

No. 8,

Umeda, Kita-ku, Osaka City

Tel: [phone]

Yokogawa-Hewlett-Packard

No. 4, 3-chome, Himeikedori,
Chigusa-ku, Nagoya City
Tel: 75-8545

KOREA

American Trading Company, Korea, Ltd.
112-35 Sokong-Dong, Jung-ku
Seoul P. 0. Box 1103, Seoul
Tel: 3-7049, 3-7613

V.m.b.H.

Naoroji Rd., Bombay 1

&

Engineering Ltd.

1

S.p.A.

Ltd.

Ltd.

Ltd.

Ltd.

NETHERLANDS

Hewlett-Packard Benelux N.V.
23 Burg Roellstraat, Amsterdam

Tel: [phone] and 13.54.99

ZEALAND

NEW

Sample Electronics (N.
8 Matipo Street
Onehunga S. E. 5, Auckland
Tel: 565-361

NORWAY

Morgenstierne
lngenifirfirma

6

Wessels Gate, Oslo

Tel: 20 16 35

1

1

PORTUGAL

TELECTRA

Rua Rodrigo da Fonseca 103

0. Box 2531. Lisbon

P.
Tel: 68 60 72 and 68 60 73 and 68 60 74

PUERTO

San Juan Electronics, Inc.

Ponce de Leon, Stop 3

150
P. 0. Box 5167
Pta. de Tierra Sta.,
Tel: [phone]

SPAIN

ATAIO, lngenieros
Enrique Larreta 12, Madrid 6
Tel: [phone] and 235.43.45

SOUTH AFRICA

F. H. Flanter & Co. (Pty.), Ltd.
Rosella House

Buitencingle Street, Cape Town
Tel: 3-3817

SWEDEN

H-P lnstrument AB

Centralvagen 28, Solna.
Tel: [phone] and 10-83.08.30

SWITZERLAND

ax-~aul

Wankdorffeldstrasse 66, Berne
Tel: [phone]

TAIWAN (FORMOSA)

Hwa Sheng Electronic
21 Nanking West Road, Ta~pe~

Tel: 4 6076,4 5936

TURKEY

TELEKOM Engineering Bureau
P.O. Box
Tel: 49.40.40

UNITED

Hewlett-Packard Ltd.
Dallas Rd.,
Tel: Bedford 68052

VENEZUELA

Citec, C. A.
Edif. Arisan-Of
Avda. Francisco de Miranda-Chacaito
Apartado del Este 10.837, Caracas
Tel: 71.88.05

YUGOSLAVIA

Belram S.A.
83 Avenue des Mimosas

Brussels 15, Belgium
Tel: 35.29.58

&

Co. WS

RlCO & VIRGIN ISLANDS

San Juan 00906

Frey

37&Galata, Istanbul

KINGDOM

Bedford, England

#4

Z.)

Ltd.

1

Centrum

Co.,.

Ud.

W.

IN

EUROPE

Hewlett-Packard, S. A.

54 Route des Acacias

Geneva, Switzerland
Telephone:
Telex: 2.24.86

Cable: HEWPACKSA

(022) 42.81.50

For Sales and

Service Assistance in Areas Not

IN

LATIN AMERICA

Hewlett-Packard
1501 Page Mill Road
Palo Alto, California 94304, U.S.A.

Telephone:

TWX:

910-373-1267

Telex: 033811 Cable:

InterAmericas

[phone]

HEWPACK

Listed

Contact:

ELSEWHERE

Hewlett-Packard
International Marketing Department

1501 Page Mill Road
Palo Alto, California 94304, U.S.A.
Telephone:

MIX:

Telex: 033811 Cable:

[phone]

910-373-1267

HEWPACK