Agilent Technologies 300A Operating Manual

Errata

Title & Document Type: 300A Harmonic Wave Analyzer
Manual Part Number: N/A
Revision Date: 11/30/1955

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Hewlett-Packard's former test and measurement, semiconductor products and chemical
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For example, model number HP8648A is now model number Agilent 8648A.

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t

OPERATING

MANUAL

PLUS

SERVICE

MANUAL

MODEL

300A

HARMONIC

WAVE

ANALYZER

This

isacombined

Operation,

Instruction,

and

Service

Manual

for

all

~

Mode1300A

Harmonic

Wave

Analyzers.

This

manual

contains

complete

operation

and

servicing

instructions

for

the

300A

and

may

be

used

in

place

of

thl~

Instruction

and

Operating

Manual

originally

supplied

with

each

ins

trument.

Copyright

1956

by

Hewlett-Packard

Company

The

information

contained

in

this

booklet

is

intended

for

the

operation

and

main-

tenance

of

Hewlett-Packard

equipment

and

is

not

to

be

used

otherwise

or

reproduced

without

the

written

consent

of

the

Hewlett-

Packard

Company.

HEWLETT-PACKARD

COMPANY

PAGE

MILL

ROAD,

PALO

ALTO,

CALIFORNIA,

U.S.A.

II

MODEL

300A

HARMONIC

WAVE

ANALYZER

INSTRUCTION

&

OPERATING

MANUAL

TABLE

OF

CONTENTS

SECTION

I

GENERAL

Page

1-1

1-2

GENERAL

DESCRIPTION

SPECIFICATIONS

• • •

· . . .

· .

· .

· .

III
III

SECTION

II

OPERATING

INSTRUCTIONS

2

-1

23D

VOLT

OPERATION.

·

· ·

·

·

·

·

· · · ·

•

III

2

-2

CONTROLS

&

TERMINALS

· · ·

·

·

· · · · ·

•

IV

2

-3

OPERATION.

. . . .

· ·

·

· · · · · · ·

• •

· · · · ·

IV

2-4

CALIBRATION

ADJUSTMENT

PROCEDURE.

·

·

·

• •

IV

2

-5

MEASUREMENT

PROCEDURE.

· · · · ·

•

·

·

·

IV

2

-6

MEASUREMENT

PRECAUTIONS.

·

· · · · · · · ·

•

V

2-7

SELECTIVITY.

. . .

· · · · · · · · · ·

•

V

SECTION

III

CIRCUIT

DESCRIPTION

3-1

GENERAL

••••

· . . . . . . . . . .. . . . .

SECTION

IV

MAINTENANCE

VI

4-1

CABINET

REMOVAL.

· · · · ·

·

· · ·•· ·

•

·

·

VII

4-2

TUBE

REPLACEMENT.

·

· · · · · · ·

·

·

•

·

•

·

•

·

VII

4-3

LOCAL

OSCILLATOR

AMPLITUDE

ADJUSTMENT.

•

·

VII

4-4

VOLTAGE

REGULATOR

ADJUSTMENT.

· ·

• • •

·

•

·

•

VII

4-5

HUM

BALANCE

ADJUSTMENT.

· ·

•

·

• • • • • • • •

·

VII

4-6

BALANCED

MODULATOR

ADJUSTMENT.

•

· ·

• •

·

VII

4-7

SELECTIVE

AMPLIFIER

ADJUSTMENT

· ·

•

· ·

•

·

VII

SECTION

V

TABLE

OF

REPLACEABLE

PARTS

5-1

GENERAL.

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

VII

THE

ATTACHED

300A-2

SERVICE

MANUAL

HASASEPA-

RATE

INDEX

APPEARING

ON

PAGE

1.

..

III

INSTRUCTION

&

OPERATING

MANUAL

SECTION

I

GENERAL

1-1

GENERAL

DESCRIPTION

The

Model

300A

Harmonic

Wave

Analyzer

isaselective

voltmeter

designed

to

measure

the

individual

components

of

complex

waves.

The

selectivity

can

be

varied

by

means

of

selective

amplifiers

to

measure

either

closely

or

widely

spaced

harmonics.

The

instrument

coversthe

audio

spectrum

from

30

to

16,000

cps.

It

has

a

wide

voltage

range

so

that

full

scale

readings

may

be

ob-

tained

from

1

millivolt

to

500

volts

0

The

Model

300A

is

well

adapted

to

the

measurement

of

the

harmonic

distortion

in

audio

frequency

equipment

of

all

kinds,

broadcast

receivers,

transmitters;

to

determine

the

harmonic

components

in

ac

machinery

and

power

systems;

to

the

study

of

induced

voltages

on

telephone

lines;

and

to

measurement

of

hum

components

in

rectifier

circuits.

Other

uses

include

the

study

of

noise

by

integrating

portions

of

the

spectrum

with

the

selectivity

control

adjusted

for

a

wide

pass

band

and

the

checking

of

wave

filter

characteristics

with

maximum

selectivity.

The

Model

300A

is

also

useful

asadevice

to

measure

the

amount

of

cross

or

intermodulation

products

generated

by

the

simultaneous

transmis

sion

of

two

frequencies

by

an

audio

system

or

to

measure

demodulation

ofamodulated

wave

applied

through

an

audio

system.

1

-2

SPECIFICATIONS

Complete

specifications

for

the

cEiJ

Model

300A

Harmonic

Wave

Analyzer

will

be

found

on

page

3

of

the

cEiJ

No.

300A-2

Service

Manual.

SECTION

II

OPERATING

INSTRUCTIONS

2-1

230

VOLT

OPERATION

This

instrument

is

shipped

from

the

factory

with

the

power

transformer

pri-

maries

connected

in

parallel

for

operation

from

115

volts.

If

operation

from

a

power

line

of

230

volts

is

desired,

the

power

transformer

primaries

must

be

connected

in

series

as

shown

by

the

"Transformer

Detail"

on

the

schematic

diagram

in

Fig.

3

on

page

39

of

the

No.

300A-2

Service

Manual.

Some

older

instruments

have

a

power

transformer

with

a

single

primary

wind-

ing

for

operation

from

115

volts

only.

The

1.

25

ampere

slo-blo

fuse

required

for

115

volt

operation

must

be

replaced

by

a

0.6

ampere

slo-blo

fuse

after

changing

primary

connections

from

parallel

to

series

for

operation

from

230

vo.lts.

IV

2-2

CONTROLS

AND

TERMINALS

All

controls

and

terminals

are

fully

des

cribed

on

pages

4

and

5

of

the

r5j:;

No.

300A-2

Service

ManuaL

CAUTION

THIS

INSTRUMENT

IS

ACCURATE

AT

AMBIENT

TEMPERATURES

OF

APPROXIMATELY

55

TO

95

DEGREES

FAHRENHEIT.

OTHER

AMBI-

ENT

TEMPERATURES

MAY

NECESSITATE

REALIGNMENT

OF

THE

SELECTIVE

AMPLIFIER

SYSTEM.

2-3

OPERATION

The

operation

of

the

Model

300A

is

divided

into

two

parts.

the

calibration

adjustment

procedure

and

the

measurement

procedure.

2-4

CALIBRATION

ADJUSTMENT

PROCEDURE

This

procedure

will

be

found

under

the

heading

of

CALIBRATION

PROCE-

DURE

starting

on

page

11

of

the

r5j:;

No.

300A-2

Service

Manual.

See

the

important

operating

precautions

given

in

step

26

of

CALIBRA

TION

PROCEDURE

in

the

No.

300A-2

manual.

2-5

MEASUREMENT

PROCEDURE

The

instrument

must

be

calibrated

before

attempting

a

measurement.

In

the

following

procedure,

the

voltage

being

analyzed

has

a

fundamental

frequency

of

80

cps

and

an

amplitude

of

20

volts.

The

frequency

and

amplitude

of

this

hypothetical

voltage

have

been

as

sumed

to

simplify

the

instructions.

Any

voltage

between

1

millivolt

and

500

volts

at

any

frequency

between

30

to

16,

000

cps

could

be

similarly

measured.

A

harmonic

frequency

must

not

be

higher

'than

16.

000

cps

if

the

particular

harmonic

voltage

is

to

be

measured.

a.

Calibrate

the

300A

as

previously

described.

b.

Set

the

METER

MULTIPLIER

control

to

50

(XIOO)

and

the

SET

TO

100

FOR

VOLT

AGE

MEASUREMENT

control

to

100.

c.

Set

the

HALF

BAND

WIDTH

control

to

30.

See

step

26B

on

page

12

of

No.

300A-2

Service

Manual

regarding

the

degree

of

selectivity

neces-

sary

for

measuring

voltages

of

various

frequencies.

d.

Set

the

frequency

dial

to

80

cps

and

peak

the

meter

indication

by

adjust-

ing

the

FINE

TUNING

control.

The

METER

SENSITIVITY

control

should

be

adjusted

to

giveareadable

indication

on

the

millivoltmeter.

The

in-

strument

is

now

tuned

to

measure

the

amplitude

of

the

fundamental

fre-

quency

(80

cps)

with

the

harmonics

excluded.

e.

The

actual

value

of

the

funda'mental

voltage

is

found

by

multiplying

the

millivoltmeter

indication

by

the

multiplying

factor

shown

by

the

position

of

the

METER

MULTIPLIER

control.

J

Example:

METER

SE.

SITIVITY

at

500

(5.aon

meter

scale)

full

scale

millivolts.

Meter

pointer

at

2.atherefor

e

meter

actually

indicates

200

millivolts.

200

millivolts

x

100

(meter

multiplier

factor)

is

equal

to

20,

000

millivolts

or

20

volts.

2-5

MEASUREMENT

PROCEDURE

(Contld.)

v

..

£.

Turn

the

frequency

dial

to

160

cps

(second

harmonic

of

80

cps)

and

set

the

METER

SEl

SITIVITY

and

METER

MULTIPLIER

controls

to

obtain

a

read-

able

meter

indication.

Use

the

FINE

TUNING

control

to

peak

the

meter

indication.

The

meter

indication

times

the

meter

multiplying

factor

will

give

the

amplitude

of

the

second

harmonic.

g.

Repeat

step

f.

at

as

many

higher

harmonics

as

desired

until

the

harmonic

voltages

become

too

small

to

measure.

In

some

cases,

the

harmonic

fre-

quency

will

be

higher

than

16,

000

cps

which

will

be

outside

the

range

of

the

300A.

2-6

MEASUREMENT

PRECAUTIONS

The

results

obtained

with

the

300A

will

depend

upon

how

clos~ly

the

operator

follows

a few"

simple

but

very

important

operating

precautions.

These

pre-

cautions

are

given

in

step

26

of

PROCEDURE

FOR

CALIBRATION

on

page

12

of

1$

o.

300.1\-2

Service

Manual.

In

addition,

a

20

KC

filter

should

be

used

between

the

voltage

to

be

measured

and

the

input

terminals

of

the

Model

300A

when

voltages

at

frequencies

of5KC

or

10

KC

are

being

measured.

This

filter

will

prevent

the

fourth

harmonic

of

the

5

KC

volt3.ge

or

the

second

harmonic

of

the

10

KC

voltage

from

entering

the

20

KC

seJ.ective

amplifier

and

causing

erroneous

measur~ments.

2-7

SELEC

TIVITY

When

operati.ng

the

Model

300A,

it

should

be

borne

in

mind

that

the

instrument

isafrequency

selective,

wide

range

voltmeter

whose

selectivity

is

variable.

It

is

necessary

during

operation

to

determine

the

degree

of

selectivity

desired

and

to

adjust

the

instrument

correctly

to

obtain

that

degree

of

selectivity.

Determination

of

the

proper

selectivity

to

use

inaparticular

measurement

should

primarily

be

based

on

the

fact

that

unwanted

voltages

must

be

attenu-

ated

by

the

selectivity

of

the

instrument

to

less

than

one

third

of

the

voltage

under

measurement.

This

attenuation

is,

in

turn,

dependent

upon

the

order

of

separation

of

unwanted

voltages

from

the

desired

voltage,

and

the

relative

magnitudes

of

the

various

voltages

involved.

Instrument

selectivity

is

controlled

by

the

HALF

BAND

WIDTH

control

which

is

calibrated

from

"30"

to

"145".

These

calibrations

indicate

the

frequency

separation

fr~m

the

center

frequency

at

which

the

selectivity

characteristics

of

the

instrument

attenuates

by

40

db

(99%).

Another

way

of

saying

the

same

thing

is

that

the

HALF

BAND

WIDTH

calibra-

tions

indicate

the

minimum

frequency

separation

from

a

100%

voltage

which

will

permit

accurate

measurement

ofa3%

voltage.

It

will

often

be

found

convenient

to

use

only

two

degrees

of

selectivity

as

ob-

tained

by

setting

the

HALF

BAND

WIDTH

control

at

"145"

for

minimum

VI

2-7

SELECTIVITY

(Contld.)

selectivity

or

at

"30"

for

maximum

selectivity.

Usemlmmum

selectivity

for

voltages

with

a

fundamental

frequency

higher

than

100

to

300

cps.

Use

maximum

selectivity

for

voltages

withafundamental

frequency

lower

than

100

to

300

cps.

This

system

eliminates

the

necessity

of

determining

whether

an

intermediate

degree

of

selectivity

offers

sufficient

attenuation

for

the

case

at

hand.

Occasionally,

however,

it

is

desirable

to

use

degrees

of

selectivity

which

are

intermediate

between

minimum

and

maximum.

An

example

follows

to

illus-

trate

a

typical

case

of

selectivity

determination.

Refer

to

Fig.

2

on

page

38

of

the

No.

300A-2

Service

Manual

which

shows

the

selectivity

characteristics

of

the

300A

for

the

two

extremes

of

the

HALF

BAND

WIDTH

control.

A

convenient

graph

for

converting

attenuation

in

terms

of

decibels

to

percentage

is

given

in

Fig.

9

on

page

45

of

the

No.

300A-2

Service

ManuaL

The

graphs

of

Figs.

2

and9are

used

to

determine

the

setting

of

the

HALF

BAND

WIDTH

control

as

illustrated

in

the

following:

As

sume

that

it

is

desired

to

measure

the

harmonics

of

an

80

cps

funda-

mental

and

that

harmonics

which

are

0.50/0

or

higher

are,of

interest.

Unwanted

voltages

must

be

attenuated

to

less

than

1/3

of

the

voltage

under

measurement

and

for

this

particular

case

it

would

be

1/3

of

1/20/0

or

1/6

of

10/0.

In

other

words,

when

measuring

the

second

harmonic,

the

funda-

mental

must

be

reduced

to

1/6

of

10/0ofits

value

by

the

300A

selectivity

characteristics.

Referring

to

Fig.

9,

we

see

that

1/6

of

1%

is

equivalent

to

approximately

56

decibels.

Therefore,

the

HALF

BAND

WIDTH

con-

trol

must

be

adjusted

so

that

the

instrument

will

attenuate

by

56

decibels

for

a

frequency

separation

of

80

cps.

Refer

to

Fig.

2

and

sketch

inacurve

similar

to

the

two

curves

shown.

The

new

curve

should

pass

through

the

56

db

point

at

80

cps

off

resonance.

Note

the

point

where

the

new

curve

passes

the

40

db

line.

This

point

has

an

abscissa

of

about

50

cycles

off

resonance.

Therefore,

the

HALF

BAND

WIDTH

control

should

be

set

at

"50"

to

obtain

56

db

attenuation

at

80

cps

off

resonance.

The

instrument

must

then

be

calibrated

using

a

HALF

BAND

WIDTH

setting

of

"50"

instead

of

"30"

in

steps

20

through

23

of

PROCEDURE

FOR

CALIBRATION

on

page

12

of

No.

300A-2

Service

Manual.

See

step

26B

on

the

same

page

for

additional

information.

SECTION

III

CIRCUIT

DESCRIPTION

3-

1

GENERAL

The

circuitry

of

the

rFeJ

Model

300A

Harmonic

Wave

Analyzer

is

discussed

on

pages

8,

9,

10,

and

11

of

the

(/!j)

No.

300A-2

Service

Manual.

•

VII

SECTION

IV

MAINTENANCE

4-1

CABINET

REMOVAL

To

remove

the

instrument

from

the

cabinet

it

is

necessary

to

unscrew

the

eight

large

Phillips

head

screws

on

~he

control

panel

and

slide

the

instrument

forward

out

of

the

cabinet.

In

some

older

instruments,

it

may

be

necessary

to

remove

the

wire

connect-

ing

the

bottom

chassis

to

the

metal

plate

in

the

bottom

of

the

cabinet.

This

wire

will

be

found

on

the

rear

of

the

instrument.

4-2

TUBE

REPLACEMENT

Refer

to

page

7

of

Service

Manual

No.

300A-2

for

complete

instructions

on

tube

replacements.

4-3

LOCAL

OSCILLATOR

AMPLITUDE

ADJUSTMENT

This

adjustment

can

be

made

at

any

time

as

directed

in

step

2

of

PRELIMI-

NARYTESTS

&

ADJUSTMENTS

on

page

13

of

No.

300A-2

Service

Manual.

4-4

VOLTAGE

REGULATOR

ADJUSTMENT

The

output

of

the

regulated

power

supply

section

in

the

300A

should

be

checked

from

time

to

time

as

directed

in

step1of

PRELIMINARY

TESTS

&

ADJUST-

MENTS

on

page

13

of

No.

300A-2

Service

Manual.

4-5

HUM

BALANCE

ADJUSTMENT

The

hum

balance

control

R159

is

located

on

the

bottom

deck

of

the

instrument

next

to

the

heater

transformer.

The

procedure

for

adjusting

this

control

is

given

in

FINAL

TEST

step

8

on

page

17

of

No.

300A-2

Service

Manual.

•

4-6

4-7

BALANCED

MODULATOR

ADJUSTMENT

The

procedure

for

adjusting

the

balanced

modulator

to

minimize

harmonic

distortion

is

given

on

page

18

of

No.

300A-2

Service

Manual

in

step

10

under

FINAL

TEST.

SELECTIVE

AMPLIFIER

ADJUSTMENT

The

detailed

procedure

for

adjusting

the

selective

amplifier

system

in

the

300A

is

given

on

pages

14

and

15

of

the

No.

300A-2

Service

Manual.

SECTION

V

TABLE

OF

REPLACEABLE

PARTS

5-1

GENERAL

A

table

of

replaceable

parts

which

is

suitable

for

use

with

all

300A

instruments

is

given

in

the

~

No.

300A-2

Service

Manual.

This

table

begins

on

page

51

of

the

manual.

I

•

OPERATION

AND

SERVICE

MANUAL

FOR

MODEL

300A

HARMONIC

WAVE

ANALYZER

300A-2A

This

isacombined

Operation

and

Service

Manual

for

all

c5j;

Model

300A

Harmonic

Wave

Analyzers.

This

manual

contains

complete

operation

and

servicing

in-

structions

for

the

300A

and

may

be

used

in

place

of

the

Instruction

and

Operating

Manual

originally

sup-

plied

with

each

instrument

•

Copyright

1955byHewlett-Packard

Company

The

information

containedinthis

booklet

is

intended

for

the

operation

and

main-

tenanceofHewlett-Packard

equipment

and

is

nottobe

used

otherwiseorreproduced

without

the

written

consentofthe

Hewlett-

Packard

Company.

HEWLETT-PACKARD

COMPANY

275

PAGE

MILL

ROAD,

PALO

ALTO,

CALIFORNIA,

U.S.

A.

300A002

,

..

Typical

Front

View

of

-hp-

Model

300A

Harmonic

Wave

Analyzer

'.

..

TABLE

OF

CONTENTS

&

INDEX

SPECIFICATIONS.

ACCESSOR'IES

AV

AILAB

LE

CONTROLS

&

TERMINALS.

TUBE

COMPLEMENT

&

TUBE

REPLACEMENTS

1.

PAGE

3

3

4

7

CIRCUIT

DESCRIPTION
General
Input&Phase

Inverter

Circuits.

Modulator

Cir

cuit&Voltage

AInplifier.

Local

Oscillator.

Power

Supply

•

Selective

Amplifier

System.

Voltmeter

Circuit.

CALIBRATION

PROCEDURE
General
Procedure

for

Calibration

.

-'

8

8

9

9

10
10
11

11
11

TEST

PROCEDURE

Instruments

Required

for

Test

Procedure

Preliminary

Tests

&

Adjustments.

1.

Adjustment

of

B+

•

2.

Adjustment

ot:

Local

Oscillator

Injection

Voltage.

3.

Centering

Tuning

Range

of

"F"

Control

•

4.

Check

Os

cillator

Stability

•

S

ele

ctiveAmplifier

Alignment

Heat

Run

Check.

Final

Test

1.

Check&Adjust

Regulated

B+

Voltage.

2.

Check&Adjust

Oscillator

Injection

Voltage

3.

Oscillator

Response

to

Line

Voltage

Change.

4.

Final

Alignment

of

Selective

Amplifier

5.

Adjust

Millivolts

Meter

to

Zero

6.

Centering

Range

of

Control

"C"

7.

Check

for

Carrier

Leakage

•

8.

Check

for

Hum

(Balance

Hum

ControlR159)

•

9.

Check

Resonance

Curves

•

10.Check

Harmonic

Distortion

(Adjust

ControlR117)

11.

Checking

Variable

Selectivity

Contol

12.

Checking

Millivolts

Meter

Tracking.

.13.

Checking

Instrument

Sensitivity

14.

Frequency

Calibration

-

Check&Adjustment

15.

Frequency

Response

Check

16.

Check

Voltage

Calibration.

17.

Checking

Meter

Sensitivity

Control

18.

Checking

Meter

Multiplier

Control

•

19.

Correcting

Unsteady

Millivolts

Meter

Readings

20.

Adding

"CALIBRATION

PROCEDURE"

Labels

21.

Mechanical

Inspection.

22.

Instrument

Bottom

Plate

Replacement.

23.

Completion

of

Final

Test

CIRCUIT

MODIFICATIONS
General
Top

Deck

Modernizing

Procedure.

Parts

Required

for

Complete

Top

Deck

Modernization.

Bottom

Deck

Modification

Procedure

Modification

to

Reduce

Carrier

Leakage.

Power

Supply

Modification

•

Other

Lower

Deck

Modifications

TROUBLE

SHOOTING

General

Trouble

Chart.

13
13
13

13

14
14
14
16
16
16
16

16
16
16
16
16
17
17
18
18
18
18
19
19

20
20
21
21
21
21
21
21

23
23

24

25
25
26

27

29
29

2.

TABLE

OF

REPLACEABLE

PARTS

General

..•••.••

Replaceable

Parts

Table

•

List

of

Manufacturers

Code

Letters

for

Replaceable

Parts

Table

;

PAGE

37
38

39

40

41

42
43
44
45
46
47
48
49

51
51
50

..

TABLE

OF

CONTENTS

&

INDEX

(Cont'd.)

Fig.

1•

Fig.

2.

Fig.

3.

Fig.

4.

Fig.

5.

Fig.

6.

Fig.

7.

Fig.

8.

Fig.

9.

Fig.

10.

Fig.

11.

Fig.

12.

Fig.

13.

FIGURES

&

ILLUSTRATIONS

Block

Diagram

of

-hp-

Model

300A

Analyzer.

•

Characteristics

of

Selective

Amplifier

System.

Schematic

Diagram

Serial

No.

1330&Above

-

Selective

Amplifier

(Top

Deck)

•••••

Schematic

Diagram

Serial

No.

1610&Above

-

Modulator,

Oscillator,

Power

Supply

(Lower

Deck).

Typical

Schematic

Diagram,

Serial

No.

1329&Below

-

Selective

Amplifier

(Top

Deck)

••••••••••

Typical

Schematic

Diagram,

Serial

No.

1609&Below

-

Modulator,

Oscillator,

Power

Supply

(Lower

Deck).

Partial

Schematic

Diagrams

Showing

Early

Circuitry.

Chart

for

Plotting

Selectivity

Curves

• • .

Decibel

to

Voltage

Ratio

Conversion

Graph

Top

ViewofTypical

Bottom

Deck

• • • •

Bottom

ViewofTypical

Bottom

Deck

• • • •

Top

ViewofTypical

Top

Deck-Less

Panel.

Bottom

ViewofTypical

Top

Deck-Less

Bottom

Plate

.\

\

•

3.

SPECIFICA

TIONS

FREQUENCY

RANGE

-

30to16,000

cycles

per

second.

FREQUENCY

CALIBRATION

-

Within

±3%orbetter.

VOLTAGE

RANGES

-

Covers

range

between

0.1

millivolt

and

500

volts

with

full

scale

readings

of:

500,

250,

100,

50,

25,

10,

5,

2.5,

l.O,

0.5,

0.25,

and

0.1

volts

plus

full

scale

millivolt

ranges

of

50,

25,

10,

5,

2.5,

and

1.

OVERALL

VOLTAGE

ACCURACY

-

Voltage

readings

are

accurate

to

within

±5%offull

scale

value

provided

harmonics

are

spaced

soastobesuppressed

by

the

selectivity

of

the

instrument.

RESIDUAL

MODULATION

PRODUCTS

-

Suppressed

at

least

65

db.

EUM

VOLTAGE

-

l\t

least

73dbbelow

0.5,

:>,

50,

or

500

volts,

depending

upon

input

range

selected.

SELECTIVITY

-

Variable

selectivity

permits

adjusting

frequencies

30to145

cps

away

from

the

resonant

fre-

quency

so

they

are

40dbbelow

th:~

resonant

frequency

while

maintaining

constant

gain.

-\PPROX.

db

BELOW

MAXIMUM

RESPONSE

3

db

10

db

40

db

60

db

INPUT

IMPEDA

TCE -

'DEVIATIO

FROM

CENTER

FREQUENCY

'.'1ITE

MAXIMUM

SELECTIVITY

3.5

cps

8.0

cps

30.0

cps

53.0

cps

DEVIATION

FROM

CENTER

FREQUENCY

WITH

MINIMUM

SELECTIVITY

14

cps

37

cps

145

cps

280

cps

•

Input

impedance

is

200,000

ohms.

POWER

-

115or2.30

volts,

±10%

50to60

cps

105

watts

DIMENSIONS

-

Cabinet

Medel:

Rack

Model:

23"

wide,

24"

high,

14"

deep.

19"

wide,

2.2.-3/1"

high,

12"

deep.

l.1)
l.1)

---

o

<'"'l

---

......

.....

"/EIGHT

-

80

pounds

for

either

model.

Shipping

weight

of

cabinet

model

is

150

pounds.

ACC

ESSOR

IES

,1\

V

IIlLAB

LE

-

The

following

accessories

are

available

for

use

with

the

300A.

For

additional

information

see

our

local

sales

representative

or

contact

the

factory

directly.

l"'J

o
o

«:

o
o

DESCRIPTION

Cable

Assembly;

dual

banana

plugs

wlth

374"

spacmg

on

each

endofa

4

foot

length

of

RG-58/U

cable.

• • • • • • • •

••

•

•••

Cable

Assembly;

dual

banana

plug

with

3/4"

spacing

on

one

endofa 4

foot

length

of

RG-58/U

cilble

andaUG-88/Utype

BNC

male

connector

on

the

other

end.

• • • • • • • • • • • • • • •

Transformer,

Bridging;

for

connecting

300A

inputtoa

balanced

line

-hp-

MODEL

NO.

AC-16A

AC-16B
AC-60B

4.

CONTROLS

&

TERMINALS

INPUT

TERMINALS

-

The

two

binding

posts

located

in

the

lower

left

corner

of

the

control

panel

are

the

instrument

input

terminals.

The

lower

binding

post

is

connected

to

the

chassis.

METER

MULTIPLIER

MAX.

INPUT

VOLTAGE

-

This

four

position

rotary

switch

determines

the

maximum

voltages

that

may

be

applied

to

the

in-

strument

without

cir

cuit

overloading.

This

control,

in

conjunction

with

the

METER

SENSITIVITY

control,

indicates

the

multiplication

factor

for

the

MILLIVOLTS

meter

reading.

The

figures

near-

est

the

knob

are

the

maximum

voltages

while

the

outer

figures

are

the

multiplication

factors.

SET

TO

100

FOR

VOLTAGE

MEASUREMENT

-

This

potentiometer

provides

a

control

for

reduCing

the

input

voltage

as

required

for

relative

volt-

age

measurements.

This

control

is

calibrated

from0to

100inarbitrary

units.

OPERATING

PRECAUTION

VOL

TAGE

MEASUREMENTS

ARE

CORRECT

ONLY

WHEN

THE

SET

TO

100

FOR

VOLTAGE

MEAS-

UREMENT

CONTROLISSET

TO

"100"

AND

THE

HALF

BANDWIDTH

CONTROLISSET

TO

THE

SAME

POSITIONS

SELECTED

FOR

CALIBRATION.

NEGATIVE

FEEDBACK

-

This

control

is

used

to

maintain

constant

amplifier

gain

with

different

settings

of

the

HALF

BAND

WIDTH

control

andiscalibrated

50-0-50.in

arbitrary

units.

Instructions

for

setting

this

control

are

given

in

the

PROCEDURE

FOR

CALIBRATION.

Some

older

instruments

in

the

field

are

not

provided

with

this

control.

In

these

instruments,

it

will

be

necessary

to

recalibrate

each

time

the

setting

of

the

HALF

BAND

WIDTH

control

is

changed.

HALF

BAND

WIDTH

-

Instrument

selectivity

is

determined

by

the

setting

of

this

control.

The

calibrations

of30to

145

on

the

scale

around

this

control

knob

indicate

the

number

of

cycles

off

resonance

the

input

signal

must

beinorder

to

be

attenuated

40

db.

Instructions

for

setting

this

control

are

given

in

the

PROCEDURE

FOR

CALIBRATION.

FREQUENCY

DIAL

-

..

;

v;

C
C

>

C

C

r-;

The

frequency

dial

and

internal

tuning

capacitor

are

driven

by

the

vernier

knob

in

the

center

of

the

dial.

The

dial

scale

is

calibrated

from0to16KCinterms

of

the

input

signal

frequency.

METER

SENSITIVITY

-

This

tapped

voltage

divider

controls

the

amplitude

of

the

voltage

supplied

to

the

selective

amplifier

and

the

position

of

the

knob

indicates

the

full

scale

value,

in

millivolts,

of

the

meter

scale

in

use.

MILLIVOLTS

METER-

This

meter

indicates

the

voltage

measured

by

the

instrument.

The

meter

has

three

scale

calibra-

tions.

The

scale

in

use

and

the

scale

multiplication

factor

are

indicated

by

the

position

of

the

METER

SENSITIVITY

FULL

SCALE

MILLIVOLTS

and

the

METER

MULTIPLIER

MAX.

INPUT

VOLTAGE

controls.

FINE

TUNING

-

This

variable

capacitor

provides

an

incremental

adjustment

for

the

frequency

dial.

The

instru-

ment

is

calibrated

with

this

control

rotated

so

that

the

mark

on

the

knob

skirt

is

straight

up

over

the

center

of

the

control.

ON-OFF

SWITCH

-

This

toggle

switch

controls

the

power

supplied

to

the

instrument

from

the

power

line.

When

the

instrument

is

turned

on,

the

indicator

lamp

below

the

toggle

switch

wfll

light.

•

U')
U')

-

o

("1"\

-

-

-

N

o

o

~

o
o

("1"\

5.

CONTROLS&TERMINALS

(Contld.)

POWER

CABLE

-

There

are

three

wires

in

the

power

cable.

Twoofthese

wires

(usually

black

and

white)

carry

power

to

the

instrument.

The

remaining

wire

(usually

green)

is

connected

internally

to

the

instru-

ment

chassis

and

protrudes

from

the

power

cable

at

the

plug

end

for

grounding

the

instrument.

FUSE

-

The

fuseholder,

located

on

the

backofthe

lower

chas

sis

or

deck,

containsa1.25

ampere

slo-blo

cartridge

fuse.

The

fuse

may

be

replaced

by

unscrewing

the

fuseholder

cap

and

inserting

a

new

fuse.

Fast

blow2ampere

fuses

were

originally

usedinthese

instruments.

The

1.25

ampere

slo-

blo

fuses

are

recommended

for

replacement

since

they

offer

increased

instrument

protection.

Those

instruments

that

have

been

changed

for

230

volt

operation

require

a

0.6

ampere

slo-blo

fuse

for

replacement.

SUB-PANEL

CONTROLS

-

Controls

C,

F,

G.

R,

S,

andVare

located

behind

the

door

at

the

bottom

of

the

control

panel.

These

are

non-operating

controls

used

for

instrument

calibration.

CONTROL

C -

This

control

is

usedtobalance

the

capacity

across

the

two

modulation

transformer

primaries

•

CONTROL

F -

This

control

provides

an

adjustment

for

setting

the

local

oscillator

fre-

quency

to20KC

when

the

frequency

dial

is

settozero.

CONTROL

G -

Overall

instrument

gainisdetermined

by

the

setting

of

this

control.

CONTROL

R -

This

control

provides

a

resistance

balance

between

the

two

modulation

transformer

primaries.

CONTROL

S -

This

lever

switch

selects

the

input

signal

for

phase

inverter

stage

VIOl.

When

this

switch

istothe

right,

the

internal

calibrating

voltage

is

connected

to

VIOl.

With

this

switch

in

the

remaining

position,

the

input

voltage

is

connected

to

the

gridofVIOl.

CONTROL

V -

This

control

permits

setting

the

internal

calibrating

voltage

to5volts.

A

tentoone

voltage

divider

following

this

control

delivers

0.5

volts

for

instrument

calibration.

VOLTS

METER-This

meter

measures

the

internal

calibrating

voltage

as

adjusted

by

control

V.

•

..

U1
U1

-

o

C"'\

-

-

-

N

o
o

<

o

o

C"

7.

TUBE

COMPLEMENT

&:

TUBE

REPLACEMENTS

GENERAL

-

Any

tubes

with

RETMA

standard

characteristics

may

be

used

for

replacement

purposes.

However,

as

notedinthe

instructions

that

follow,

useofa

selected

tube

will

improve

instrument

performance

in

some

cases.

The

300Aisa

high

gain

instrument.

Tubes

that

are

microphonic

or

have

relatively

high

heater

to

cathode

leakage

are

not

desirable.

The

tube type

used

for

some

of

the

stages

in

the

300A

have

varied

with

time.

In

some

cases

use

of

a

later

tube

typeisrecommended

but

not

neces

sary.

Ifindoubt,

replace

tubes

with

the

same

type

foundinthe

instrument.

The

number

of

adjustments

required

will

depend

upon

the

tube

replaced.

The

specific

tests

and/or

adjustments

are

given

in

the

chart

that

follows.

This

chart

also

shows

where

the

procedures

for

these

tests

and

adjustments

can

be

foundinthe

TEST

PROCEDURE

section

of

this

manual.

CIRCUIT

ORIGINAL

RECOMMENDED

TESTS,

ADJUSTMENTS,

AND/OR

REFERENCE

TUBE

TYPE

REP

LACEMENT

SPECIAL

NOTES

VI

thru

V8

6SJ7

6SJ7

FINAL

TEST

procedure

steps8and

9.

Low

microphonic

tubes

are

best.

V9

6F8

or

6F8

or

6SN7

Replace

with

same

type

asininstrument.

6SN7

FINAL

TEST

step

3.

VIO

6H6

Aged

6H6

Select

tube

giving

minimum

change

in

zero

setting

between

instrument

on

and

off

with

no

input

signal.

Complete

FINAL

TEST

step

3.

F 101 2

amp

fast

1.

25

amp

Slo-blo

fuse

gives

better

instrument

pro-

blow

or

1.25

slo-blo

tection.

Use

different

fuse

for

230

volt

amp

slo

-blo

operation

as

noted

under

FUSEinthe

for

115

V.

CONTROLS

&:

TERMINALS

section.

operation.

R140

lamp

3

watts,

115

10

watts

FINAL

TEST

step

2.

See

step1of

OTHER

volts

or

230

volts

LOWER

DECK

MODIFICATIONS

under

10

watts,

BOTTOM

DECK

MODIFICATION

PRO-

230

volts

CEDURE

in

CIRCUIT

MODIFICATIONS

section.

VIOl

6SJ7

6SJ7

FINAL

TEST

procedure

steps

3,

6,

8,

&:

10.

Useatube

with

low

microphonics

and

check

fora"hump"

in

the

resonance

V

102

&:

6SJ7

6SJ7

selected

curves

as

directed

in

FINAL

TEST

pro-

V 103

asamatched

cedure

step

9.

pair.

Vl04

6SJ7

6SJ7

FINAL

TEST

step

3.

Check

for

low

microphonics,

hum,

and

60

cps

"hump".

FINAL

TESTstep

9a.

V

105

6J7

6J7

Changing

either

tube

will

not

cause

appre-

ciable

change

in

frequency

oroscillator

inj

ection

voltage.

Check

by

repeating

steps

2,

3,

8,

10,

and14of

FINAL

TEST.

VI06

6F6

6F6

Os

cillator

output

should

be

stable.

Tubes

should

be

non-rnicrophonic.

8.

TUBE

COMPLEMENT

lit

TUBE

REPLACEMENTS

(Cont'd.)

GENERAL

(Cont'd.)

CIRCUIT

ORIGINAL

RECOMMENDED

TESTS,

ADJUSTMENTS,

AND/OR

REFERENCE

TUBE

TYPE

REPLACEMENT

SPECIAL

NOTES

NE16

Neon

Tube

NE16

The

two

tube

types

given

are

not

inter-

V

107

or

or

changeable.

Replace

with

same

type

as

OA2

OA2

foundininstrument.

Set

B+

according

to

instructions

in

step1of

FINAL

TEST.

V

108

6SQ7

or

6SF5

6SQ7

or

6SF5

6L6G,

FINAL

TEST

step

1.

Allofthese

tube

V

109

6L6GA,

6L6GB

types

have

the

same

pin

connections.

Re-

6L6GB,

or

sistor

R164

must

beinscreen

circuit

if

6Y6

6Y6isused.

FINAL

TEST

step

1.

Best

power

supply

5Y3GT,

regulation

will

be

obtained

in

some

cases

VUO

5Z4,

5U4G,

5U4GB

by

replacing

with

the

same

tube

type

as

5U4GA,

or

in

instrument.

Allofthese

rectifiers

5U4GB

are

interchange;;ible

in

the

300A

with

no

change

in

pin

connections.

Voltage

rating

of

output

electrolytic

capacitors

must

not

be

exceeded.

CIRCUIT

DESCRIPTION

GENERAL

-

.

.

The

-hp-

Mode1300A

Harmonic

Wave

Analyzer

isafrequency

selective

heterodyne

type

voltmeter

signed

to

measure

individual

components

of

complex

waveforms.

Full

scale

meter

readings

can

be

obtained

from

input

voltages

varying

between1millivolt

and

500

volts.

Instrument

selectivity

can

be

varied

to

measure

either

closely

or

widely

spaced

harmonics

over

the

audio

spectrum

from

30to16,

000

cps.

Basically,

the

circuit

consists

ofaphase

inverter,

a

local

oscillator,

a

balanced

mixer,

a

four

section

selective

amplifier,

andavacuum

tube

voltmeter.

In

addition

to

these

basic

circuits,

the

Model

300A

includes

input

and

range

multipliers

as

well

as

an

internal

calibrating

system

for

use

in

standardizing

overall

instrument

gain.

The

block

diagram

giveninFig.1shows

the

function

of

the

individual

circuits

and

controls.

The

instrument

is

divided

into

two

chassis

withacommon

front

panel.

The

upper

chassis

con-

tains

the

selective

amplifier

and

vacuum

tube

voltmeter

sections.

The

remalnlng

circuits

are

located

in

the

lower

chassis.

The

schematic

diagram

is

similarly

divided.

INPUT

lit

PHASE

INVERTER

CIRCUITS

-

The

input

terminals

in

the

lower

left

corner

of

the

instrument

panel

are

connected

to

METER

MULTIPLIER

switch

SlOl

which

provides

ranges

of

Xl,

XlO,

XlOO,

and

XlOOO.

In

addition,

each

position

of

this

switch

is

calibrated

in

the

maximum

input

voltage

that

may

be

applied

without

overloading

the

circuits

of

the

instrument.

Erroneous

readings

will

result

from

circuit

clipping

when

the

input

signal

is

higher

than

these

panel

markings.

The

METER

MULTIPLIER

switch

is

followed

by

the

SET

TO

100

control

which

must

be

settothe

100

position

in

order

to

obtainacorr

ect

voltmeter

reading

when

measuring

the

actual

value

of

the

input

voltage.

Switch

5102

("S")

permits

connecting

the

inputofthe

6SJ7

phase

inverter

tube

VIOltothe

input

signal

ortothe

internal

calibration

circuit.

de-

l.U

0
0

~

0
0

N

-

:-

~

l.U

0

-

U1

C11

..

lI)
lI)

-

o

l""'I

-

.....

.....

N

o

o

<

o
o

l""'I

9.

CIRCUIT

DESCRIPTION

(Cont'd.)

INPUT&PHASE

INVERTER

CIRCUITS-(Cont'd.)

The

internal

calibration

circuit

obtains

6.3

volts

fromaheater

winding

on

the

power

transformer.

Control

"V"

permits

setting

the

voltage

to

obtainareading

of5volts

on

the

internal

calibrating

voltmeter.

The

values

of

Rl06

and

Rl07

are

chosen

to

obtain

a 10to1

voltage

division

ratio

and

are

factory

adjusted

to

obtaina0.5

volt

calibration

voltage

when

the

calibration

voltmeter

reads

5

volts.

Phase

inverter

VIOlisa

triode

connected

type

6SJ7

pentode

tube.

The

load

resistor

(other

than

cathode

resistor

RIll)

for

this

tubeiseffectively

44,000

ohms

and

consists

of

Rl12

and

Rl14

in

serie-s.

With

Rl12

in

the

cathode

circuit

and

Rll4

in

the

plate-circuit,

the

signal

voltage

delivered

to

the

modulator

tubes

through

coupling

capacitors

CI03

and

Cl05

are

equalinamplitude

and

180

degrees

outofphase

with

each

other.

MODULATOR

CIRCUIT

&

VOLTAGE

AMPLIFIER

-

The

modulator

circuit

consists

of

two

type

6SJ7

tubes

(Vl02

and

Vl03)ina

balanced

push-pull

cir-

cuit.

Potentiometer

R 117

providesan

adjustment

for

balancing

the

modulator

input

circuits.

This

control

is

set

during

FINAL

TEST

andisnotanoperating

control.

Variable

capacitor

CI07

(con-

trol

"C")

and

potentiometer

R123

(control

"R")

provide

balancing

adjustments

for

the

modulator

output

circuits.

The

local

oscillator

voltage

is

injected

into

the

cathode

circuit

of

Vl02

and

Vl03atthe

topoftheir

common

cathode

resistor

(R120).

The

local

oscillator

operates

atafrequency

20

KC

higher

than

the

input

signal.

The

push-pull

modulato1l'

tubes

will

have

the

input

and

local

oscillator

frequencies

present

in

their

output

as

well

as

the

sum

and

difference

frequencies.

Transformer

TlOlisdesigned

for

operation

at20KC

and

readily

accepts

the

20

KC

lower

side-

band

and

passes

itonto

the

selective

amplifier.

These

amplifiers

are

peaked

to

amplifya20

KC

signal.

Any

portion

of

the

original

signal

arriving

at

the

inputtothis

amplifier

system

will

be

rejected

by

the

amplifier.

The

local

oscillator

signal

is

applied

to

Vl02

and

Vl03

fromacommon

source

and

hence

appears

in

both

plate

circuits

in

the

same

phase

and

will

be

cancelled

out

across

the

balanced

primary

of

TlOl.

Balance

is

obtained

by

adjusting

controls

"C"

and

"R".

This

balance

becomes

increasingly

important

at

the

lower

frequency

limit

of

the

300A.

When

the

frequency

dial

is

settozero

the

local

oscillator

frequency

is

20

KC.

If

the

modulator

tubes

are

not

balanced,

the

20

KC

signal

from

the

local

oscillator

will

feed

through

the

selective

amplifier

and

give

an

erroneous

reading

on

the

300A.

Potentiometer

R125

(control

"G")

across

the

secondary

of

TlOl

provides

an

adjustment

for

standard-

izing

overall

amplifier

gain.

METER

SENSITIVITY

switch

Sl03

permits

changing

the

amplifier

input

by

anyone

of

nine

fixed

ratios.

This

effectively

acts

asacontrol

of

meter

sensitivity

and

when

used

in

conjunction

with

the

METER

MULTIPLIER,

switch

SlOl,

provides

18

full

scale

voltmeter

ranges

from

500

volts

to

1

millivolt.

Tube

Vl04isa

triode'

connected

type

6SJ7

tube

functioning

asavoltage

amplifier.

The

output

from

this

tube

is

connected

toashielded

cable

terminated

byatwo

prong

plug.

The

shielded

cable

carries

the

20

KC

signal

from

the

lower

chassis

to

the

upper

chassis.

A

two

prong

socket

is

mounted

in

the

upper

chassis

•

LOCAL

OSCILLATOR

-

The

local

oscillator

is

the

resistance-capacity

tuned

circuit

commonly

foundin-hp-

instruments.

Tubes

Vl05

and

Vl06

function

basically

asatwo

stage

voltage

amplifier

with

the

output

of

Vl06

coupled

to

the

grid

and

cathode

circuits

of

Vl05.

The

grid

cir

cuit

coupling

produces

regenerative

feedback

to

maintain

oscillation

while

the

cathode

circuit

coupling

produces

degenerative

feedback

to

stabilize

the

oscillator

output.

The

oscillator

tunes

overarelatively

narrow

range

from

20

KCto36

KC

and

has

constant

output

over

this

range.

Consequently,

the

amplitude

of

the

20

KC

signal

fedtothe

selective

amplifier

system

is

dependent

upon

the

amplitude

of

the

input

signal.

10.

CIHCUIT

DESCrnPTlON

(Cont'd.)

LOCAL

OSCILLATOR

-

(Cont'd.)

The

frequency

dial

is

calibrakd

to

indicate

the

frequency

of

the

input

signal

and

not

the

local

oscil-

lator

frequL'ncy

which

is

lO

KC

high,"r

than

the

dial

indication.

The6to65L,,.,f

trimmer

(C

ll-l

control

"F")

provides

an

acijustment

for

setting

the

local

oscillator

frequency

...

ith

the

frequency

dial

set

to

"0".

control

"F"

is

adjusted

foramaximum

indication

on

the

300A

voltmeter.

This

adjustmr~'1t

tunes

the

local

oscillator

to

the

20

KC

peak

of

the

selec-

tive

amplifiers.

An

accurately

known

external

source

connected

to

the

300A

input

terminals

can

illso

be

used

for

adjusting

the

local

oscillator.

The

300A

frequency

dial

is

set

to

the

same

fre-

quency

as

the

external

source

and

control

"F"

is

adjusted

forama.<:imum

indication

on

the

300A

111eter.

Lo

caloscilla

tor

output

is

obtained

fr

om

VIa6cathodecircuit

and

inj

ected

into

the

cathodecir

cuit

of

VI02

and

VI03.

Injection

voltage

is

set

with

the

frequency

control

dial

at

"a"

by

adjusting

poten-

tiometer

R143

which

controls

negative

feedback

from

VI06tothe

cathode

of

VI05.

The

20

KC

in-

jection

voltage

measured

at

the

top

of

cathode

resistor

Rl20

for

VI02-

and

VI03

should

be2volts.

PO,,'ER

SUPPLY

-

High

voltage

is

obtained

froma5U4G/AB

full

wave

rectifier

followed

byatwo

section

capacity

in-

put

L-C

filter.

This

filtered

dc

output

furnishes

B+

for

all

selective

amplifier

circuits

as

..veIl

as

the

voltmeter

circuit

in

the

upper

chassis.

The

filtered

dcisalso

passed

through

a

voltage

regu-

lator,

the

output

of

which

supplies

VIOl

through

VI06inthe

lower

chassis.

An

OA2

voltage

regulator

tube

VI07

supplies

the

necessary

reference

voltage

for

the

6SQ7

regulator

control

tube

VI08

which

in

turn

controls

the

6L6GB

series

regulator

tube

VI09.

Tube

types

for

VI07, VI08.

and

VI09

may

vary

between

instruments.

Potentiometer

R152isan

adjustment

for

setting

the

output

of

the

regulated

portion

of

the

power

supply

to

+240

volts.

SELECTIVE

AMPLIFIER

SYSTEM

-

The

selective

amplifier

system

consists

ofatotal

of

eight

type

65J7

tubes.

to

give

effectively

four

amplification

stages.

All

four

stages

function

in

the

sequently,

only

the

first

stage

involving

VI

and

V2

will

be

discussed.

These

tubes

are

paired

same

manner.

Con-

The

signal

from

voltage

amplifier

Vl04inthe

lower

chassis

is

fed

through

a

shielded

cable

to

the

grid

circuit

ofVIin

the

upper

chassis.

Coil

LIinthe

grid

circuit

is

tuned

to

20

KC

by

CI

and

C2.

The

resistor

of

830,

000

ohms

in

the

grid

circuit

prevents

the

preceding

stage

from

loading

the

resonant

circuit.

The

amplified

20

KC

signal

is

developed

across

one

section

of

the

HALF

BAND

WIDTH

control.

With

this

control

rotated

full

counterclockwise,

the

control

arm

isatground

potential

and

there

is

no

feedback

from

V2toVI

through

R5, R8,R9,

or

RIO

resistors.

Amplifier

gainisdetermined

by

the

fixed

degenerative

coupling

through

R11and

C37

between

V2

output

and

VI

cathode

circuit.

Amplifier

selectivity

isatminimum

andisprimarily

determined

by

the

resonant

circuit

in

the

grid

circuit

of

VI.

Resistor

R74will

control

the

IIQIIofthe

tuned

circuit

and

hence

also

control

amplifier

selectivity

under

these

conditions.

As

the

HALF

BAND

WIDTH

control

is

rotated

clockwise,

more

and

more

of

the

plate

signal

from

V2isfed

back

to

the

grid

circuit

of

VI.

This

signal

isinphase

with

the

input

signal

and

the

cir-

cuit

becomes

regenerative.

The

selectivity

of

the

two

stages

becomes

progressively

sharper

as

regeneration

increases.

The

positive

feedback

would

also

cause

an

increase

in

gainifit

were

not

for

negative

feedback

through

R5,

R8,

and

RIOtothe

cathode

ofVIfrom

the

same

point

as

the

positive

feedback.

By

design,

circuit

constants

have

been

chosen

to

permit

adjustment

of

the

amount

of

negative

feedback.

By

properly

setting

the

NEGATIVE

FEEDBACK

control,

as

described

in

the

Operating

Instructions,

itispossible

to

vary

the

selectivity

of

stages

VI

and

V2

while

maintaining

constant

amplifier

gain.

The

remaining

three

sections

of

the

selective

amplifier

operate

inanidentical

manner.

Tubes

V3

and

V4

comprise

the

second

section,

tubes

V5

and

V6

the

third

section,

and

tubes

V7

and

V8

the

fourthsectlon.

l1"\
l1"\

-

a

r')

-

.....

.....

N

a

a

~

a

a

r')

11.

CIRCUIT

DESCRIPTION

(Cont'd.)

SELECTIVE

AMPLIFIER

SYSTEM-(Cont'd.)

The

HALF

BAND

WIDTH

control

consists

of

four

ganged

potentiometers

which

control

feedback

in

all

four

amplifier

sections

simultaneously.

This

control

is

calibrated

145to30.

The

divisions

on

this

scale

indicate

the

number

of

cycles

away

from

the

resonant

frequency

at

which

the

ampli-

fier

response

will

be

down

40db(99%).

The

NEGATIVE

FEEDBACK

control

also

consists

of

four

ganged

potentiometers

which

provide

simultaneous

negative

feedback

control

in

all

four

amplifier

sections.

This

control

is

calibrated

50-0-50

in

arbitrary

units.

The

20

KC

toroid

coils

used

in

the

selective

amplifier

sections

are

manufactured

using

the

most

uptodate

techniques

known

with

the

most

recent

engineering

data

in

order

to

insure

instrument

accuracy

over

an

ambient

temperature

range

of

approximately

55to95

degrees

Fahrenheit.

Am-

bient

temperatures

outside

of

this

range

may

necessitate

realignment

of

the

selective

amplifier.

VOLTMETER

CIRCUIT

-

The

vacuum

tube

voltmeter

voltage

amplifier,

V9,

consists

of

two

triode

sections

ofatype

6SN7GT

tube

connected

inaconventional

resistance

coupled

amplifier

circuit.

The

output

of

this

amplifier

is

fedtoa

6H6

tube

inafull

wave

rectifier

circuit.

The

ground

return

for

the

rectifier

circuit

is

made

through

the

cathode

resistor

for

the

first

triode

section.

This

introduces

inverse

or

nega-

tive

feedback

which

stabilizes

the

vacuum

tube

voltmeter

circuit.

The

indicating

meter

hasabasic

0-1

milliampere

movement

with

the

scale

calibrated

in

three

ranges

of

0-1,

0-2.5,

and

0-5

millivolts.

CALIBRA

nON

PROCEDURE

GENERAL

-

The

instrument

should

be

given

at

least

30

minutes

for

warm

up

before

starting

the

calibration

procedure.

This

warm

up

will

allow

the

circuits

to

reachastable

operating

condition.

It

is

also

advisable

to

check

the

calibration

after

the

instrument

has

been

operating

for

more

than

one

hour.

PROCEDURE

FOR

CALIBRATION

-

1.

Set

the

main

tuning

dialto"0".

2.

Set

the

FINE

TUNING

so

that

the

line

is

vertical.

3.

Set

METER

SENSITIVITY

to

"SaO".

4.

Set

HALF

BAND

WIDTHto"30".

5.

Set

NEGATIVE

FEEDBACK

to

"0".

6.

Set

METER

MULTIPLIER

to

"XIOOO".

7.

Set

input

gain

control

potentiometer

(SET

TO

100

FOR

VOLTAGE

MEASUREMENT)

full

counterclockwise

to

"a".

This

control

and

the

METER

MULTIPLIER

have

no

effect

on

the

calibration

procedure

except

to

isolate

the

input

terminals

from

the

balance

of

the

circuits.

8.

Set

switch

"S"tothe

left

(position

vertical

to

panel).

9.

Set

control

"G"tothe

center

of

its

range.

10.

-Adjust

control

"F"

foramaximum

MILLIVOLTS

meter

indication.

If

MILLIVOLTS

meter

reads

off

scale,

rotate

control

"G"tobring

pointer

on

scale.

11.

Adjust

controls

"C"

and

"R"

foraminimum

MILLIVOLTS

meter

reading.

Rotate

con-

trol

"G"toincrease

meter

readings

and

also

switch

METER

SENSITIVITY

to

lower

scales

in

order

to

increase

meter

readings.

12.

Set

HALF

BAND

WIDTHto"145".

12.

CALIBRATION

PROCEDURE

(Cont'd.)

PROCEDURE

FOR

CALIBRATION

-

(Cont'd.)

13.

Return

METER

SENSITIVITY

to

"500".

14.

Set

switch

"S"tothe

right

position.

15.

Adjust

control

"V"

foraVOLTS

meter

reading

of5volts.

16.

Set

main

tuning

dial

to

power

line

frequency

and

adjust

foramaximum

MILLIVOLTS

meter

indication.

Adjust

control

"G"

as

required

to

keep

the

MILLIVOLTS

meter

on

scale.

17.

Adjust

control

"G"

for

exactly

500

millivolts

(full

scale

on

MILLIVOLTS

meter).

18.

Flip

switch

"S"tothe

left,

METER

SENSITIVITY

switch

to

25,

and

adjust

main

tuning

dial

at

o

foramaximum

indication

on

the

MILLIVOLTS

meter.

If

MILLIVOLTS

meter

reading

is

off

scale,

adjust

"C"

and

"R"

foraminimum

meter

reading.

19.

Repeat

steps

13

through

17.

20.

Set

HALF

BAND

WIDTH

to

"30"

and

adjust

FINE

TUNING

foramaximum

MILLIVOLTS

meter

reading.

21.

Adjust

NEGATIVE

FEEDBACK

control

forafull

scale

MILLIVOLTS

meter

reading.

Rotate

control

clockwise

to

increase

reading

or

counterclockwise

to

decrease

reading.

22.

Set

HALF

BAND

WIDTH

to

"145"

and

adjust

FINE

TUNING

for

maximum

reading

on

MILLI-

VOLTS

meter.

If

reading

is

not

full

scale,

repeat

steps

13

through

17.

23.

Repeat

steps

20

through

22

untilafull

scale

MILLIVOLTS

meter

reading

is

obtained.

24.

Flip

switch

"S,,'to

the

left

and

close

the

bottom

door.

25.

Before

making

voltage

measurements,

set

front

panel

operating

controls

as

follows:

SET

TO

100

FOR

VOLTAGE

MEASUREMENT

full

clockwise,

METER

MULTIPLIER

to

proper

range

for

the

voltage

being

measured,

and

HALF

BAND

WIDTH

at

"145"

or

"30".

Main

tuning

dial

must

be

tuned

to

frequency

of

voltage

being

measured

and

the

FINE

TUNING

adjusted

for

a

maximum

MILLIVOLTS

meter

indication.

-

26.

The

following

precautions

must

be

observed

when

operating

the

-hp-

Model

300A

Harmonic

Wave

Analyzer:

A.

For

maximum

accuracy,

recheck

calibration

from

time

to

time

while

operating

instru-

ment.

B.

For

convenience,

set

the

HALF

BAND

WIDTH

control

to

"30"

when

measuring

voltages

below

300

cps

andto"145"

for

voltages

above

300

cps.

Any

desired

intermediate

points

may

be

selected

and

used

foraparticular

application

provided

these

points

are

used

in

steps

20

through

23ofPROCEDURE

FOR

CALIBRATION.

C.

To

make

voltage

measurements,

the

input

gain

control

(SET

TO

100

FOR

VOLT

AGE

MEASUREMENT)

must

be

full

clockwise

to

"100".

The

HALF

BAND

WIDTH

control

should

be

settothe

point

or

points

used

when

calibrating.

SeeBabove.

The

instrument

can

be

calibrated

and

used

with

the

HALF

BAND

WIDTH

control

set

to

provide

any

de-

sired

degree

of

selectivity

between

"30"

and

"145".

D.

The

main

tuning

dial

must

be

tuned

'to

the

signal

voltage

frequency

and

the

FINE

TUNING

control

adjusted

foramaximum

MILLIVOLTS

meter

reading.

E.

The

Model

300A

can

be

used

to

measure

huminthe

presence

of

other

signals

if

the

fol-

lowing

precautions

are

observed:

1.

The

modulator

must

be

balanced

to

10

millivolts

or

less

in

step

18ofthe

CALIBRATION

PROCEDURE.

2.

The

HALF

BAND

WIDTH

control

must

be

setto"30".

These

precautions

are

necessary,

since

this

measurement

is

ordinarily

made

on

the

ex-

tremely

sensitive

ranges

of

the

instrument

with

the

local

oscillator

tuned

to

20,060

cps.

If

the

modulator

is

not

balanced

very

closely,

the

signal

from

the

local

oscillator

may

feed

directly

into

the

selective

amplifier.

The

HALF

BAND

WIDTH

must

be

set

for

maxi-

mum

selectivity

to

provide

additional

reduction

of

the

signal

from

the

local

oscillator.

VJ

o

o

~

o
o

N

.....

.....

-

VJ

'?

-

\Jl

.,\Jl

13.

CALIBRATION

PROCEDURE

(Cont'd.)

PROCEDURE

FOR

CALIBRATION

-

(Co.l.t'd.)

F.

A

20

KC

external

signal

source

operating

near

the

300A

may

radiate

a

signal

directly

into

the

selective

amplifier

of

the

300A

and

produce

an

erroneous

MILLIVOLTS

meter

reading

orabeat.

RANGE

OF

REALIGNMENT

APPROXIMATE

AMBIENT

TEMPERATURE

AMBIENT

TEMPERATURES

MAY

REOUIRE

THIS

INSTRUMENTISACCURATE

WITHIN

THE

55

TO95DEGREES

FAHRENHEIT.

OTHER

OF

THE

SELECTIVE

AMPLIFIER.

TEST

PROCEDURE

INSTRUMENTS

REQUIRED

FOR

TEST

PROCEDURE

-

•

1.

A

constant

frequency

and

voltage

sine

wave

source

delivering

20

KC

with

not

more

than

1%

distortion.

The

-hp-

Model

200CD

''vide

Range

Oscillator

is

recommended.

A

signal

gen-

erator

with

an

output

attenuator

such

as

-hp-

Models

205A,

205AG, 205AH,

or

650A

can

al-

so

be

used

•

2.

A

frequency

measuring

device

such

as

an

-hp-

Model

521,

522,

523,

or

524

Electronic

Counter

is

recommended.

An

-hp-

Model

lOOCor100D

Secondary

Frequency

Standard

used

in

conjunction

with

an

oscilloscope

will

also

serve

the

same

purpose.

3.

A

pure

sine

wave

source

covering

the

approximate

range

from

100to6,300

cps

with

extremely

low

distortion

is

needed.

The

-hp-

Model

206A

Audio

Signal

Generator

followed

byapure

wave'

filter

is

recommended.

4.

Adcvoltmeter

such

as

-hp-

Model

410B.

5.

A

constantly

variable

transformer

for

line

voltage

control.

6.

Anacvoltmeter

such

as

-hp-

Model

330,

400AB,

or

400D.

7.

An

oscilloscope

with

response

upto36

KC.

IMPORTANT

TEST

PROCEDURES

MUSTBEPERFORMEDINTHE

SE~UENCE

GIVEN.

PRELIMINARY

TESTS&ADJUSTMENTS

-

The

instrument

should

be

turned

onatleast

an

hour

before

making

these

adjustments.

Set

the

line

voltage

to

115

volts

for

all

tests

unless

otherwise'instructed.

Unless

otherwise

designated,

refer

to

Figs.

3

and4for

circuit

references.

1.

Set

the

regulated

dc

voltage

at

cathode

pin8of

Vl09

to

240

volts

by

adjusting

control

potentio-

meter

R152.

This

control

will

not

be

found

in

some

older

instruments

anditwill

be

neces-

sary

to

pad

resistor

R50orR5l

shown

in

Fig.

7Ctoadjust

for

240

volts.

The

output

of

the

regulated

supply

should

stay

within

the

limits

of

238

and

242

volts

when

the

line

voltage

is

varied

between

102

al]-d

128

volts.

2.

Set

main

tuning

dial

to

zero

and

engraved

line

on

FINE

TUNING

knobina

vertical

position.

Measure

local

oscillator

injection

voltage

at

cathode

pin5of

Vl02

or

Vl03.

The

20

KC

volt-

age

measured

should

be2volts.

Adjust

potentiometer

R

143

until

a 2

volt

reading

is

obtained

on

the

voltmeter.

If

necessary,

selectacathode

lamp

(R140)tobring

the

oscillator

level

within

the

adjustment

range

ofR143.

Older

instruments

haveafixed

resistor

in

place

of

this

control

and

adjustment

is

made

by

padding

the

value

of

the

fixed

resistor.

14.

TEST

PROCEDURE

(Cont'd.)

PRELIMINARY

TESTS&ADJUSTMENTS

-

(Cont'd.)

3.

Set

main

tuning

dial

and

FINE

TUNING

controls

to

the

same

position

used

in

step

2.

Connect

frequency

measuring

equipment

and

ac

voltmeter

at

cathode

pin5of

Vl02

or

VI03.

Tune

local

oscillator

to20KC

by

means

of

sub-panel

"F"

control.

If

the

oscillator

cannot

be

tun_ed

to

20

KC

with

the

"F"

control

orifthis

control

does

not

tune

at

approximate

mechanical

cen-

ter

with

plates

half

meshed,

adjust

variable

capacitor

C

123,

orifnecessary

change

values

of

fixed

capacitors

Cl12

and

Cl13.

Some

early

instruments

do

not

have

variable

capacitor

C123

which

is

mounted

on

the

underside

of

the

lower

deck.

4.

Check

oscillator

for

stability.

Watch

pattern

on

oscilloscope

for

any

sudden

changes

in

fre-

quency

or

amplitude.

Change

oscillator

tubes

(Vl05

and

Vl06)

to

correct

trouble

ifitoccurs.

SELECTIVE

AMPLIFIER

ALIGNMENT

-

The

selective

amplifier

consists

of

four

stages

with

two

tubes

in

each

stage.

All

four

stages

are

aligned

in

the

same

general

manner.

The

alignment

procedure

for

instruments

with

Serial

No.

1330

and

above

or

older

instruments

which

have

been

modernized

varies

slightly

from

the

procedure

for

the

older

instruments

which

have

Serial

No.

1329

and

below

and

have

not

been

modernized.

These

alignment

differences

are

given

in

the

alignment

procedure.

The

type

of

circuit

thataparticular

instrument

has

should

be

determined

before

starting

alignment

of

the

selective

amplifier.

The

MODERNIZING

OLDER

IN-

STRUMENTS

section

of

this

manual

will

aidinthis

circuit

identification.

Input

and

output

voltages,

when

mentioned

in

the

following

procedure,

are

measured

between

the

indicated

pointinthe

circuit

and

the

chassis.

All

circuit

references

refer

to

Fig.3unless

other-

wise

noted.

The

amplifier

stage

or

section

being

aligned

can

be

determined

by

theprefix

number

I,

2,

3,

or4in

the

steps

of

the

following

alignment

procedure.

The

selective

amplifier

stages

normally

operate

with

signal

levels

of

very

low

amplitude.

All

four

stages

are

basically

the

same

and

are

each

capable

of

delivering

an

output

signal

of4volts.

Hence,

for

convenience

in

testing,

the

input

test

signal

is

adjusted

so

that

the

stage

output

voltage

does

not

exceed4volts.

lAo

Unplug

the

two

prong

connector

from

the

top

deck

and

remove

the

third

amplifier

tube

V3.

Remove

bottom

plate

on

top

deck.

lB.

Feedasignal

of

exactly

20

KC

(±5

cps)

from

an

external

source

into

the

upper

deck

two

prong

connector.

The

20

KC

source

must

meet

specifications

givenatthe

beginning

of

this

TEST

PROCEDURE

section.

Once

set,

oscillator

frequency

must

be

monitored

and

not

al-

lowed

to

vary

more

than1cps.

See

above

for

instructions

on

setting

input

signal

level.

lC.

Connect

anacvacuum

tube

voltmeter

to

the

junction

of

C7

(0.05

1Ji)

and

Rll

(68,000

ohms)

in

the

plate

circuit

of

V2.

Adjust

external

signal

source

as

required

to

maintain

a

voltmeter

reading

no

higher

than4volts.

lD.

Set

the

NEGATIVE

FEEDBACK

control

at

"-10".

This

control

remains

in

this

position

for

the

balance

of

the

alignment

procedure.

IE.

With

the

HALF

BAND

WIDTH

control

setat"30"

adjust

trimmer

Cl

across

toroid

coil

Ll

foramaximum

indication

on

the

external

vacuum

tube

voltmeter.

The

trimmer

capacitor

across

the

toroid

coil

must

not

be

tuned

with

the

lates

full0enorfull

closed.

To

do

so,

will

cause

a

alse

resonance

peak

an

when

the

ee

ac

control

isaJuste

ater

for

normal

operation,

oscillation

will

occur.

Change

the

value

of

fixed

capacitor

C2inparallel

with

the

trimmer

to

center

the

trimmer

when

tuned

forapeak.

Use

silver

mica

or

ceramic

capa-

citors

with

low

or

zero

temperature

coefficients.

IF.

Set

the

HALF

BAND

WIDTH

control

at

"145"

and

adjust

forastage

gain

of19db,

±1/2

db

by

padding

the

lower

cathode

resistor,

R2,

for

the

first

tube

in

the

stage.

Set

older

instruments

(unmodified

Serial

No.

1329

and

below)

foragain

of19to

19-1/2

db.

The

schematic

in

Fig.

3

shows

this

resistor

and

the

corresponding

resistor

in

the

following

stages

as

havinganominal

value

of

900

ohms.

The

factory

adjusted

values

of

these

resistors

will

range

from

approximately

600

ohms

upto900

ohms.

lG.

Note

the

external

voltmeter

reading

and

then

turn

the

HALF

BAND

WIDTH

control

to

"30".

Adjust

potentiometer

R8,

in

the

feedback

circuit,

to

obtain

the

same

external

voltmeter

reading.

lH.

Check

trimmer

setting

and

stage

gain

by

repeating

steps

IE

and

IF.

Ifachange

is

made,

repeat

step

lG.

Replace

tube

V3.

VJ

o

o

~

o

o

N

......

.......

-

VJ

o

-

JJt

U1

N

o

o

~

o

o

l""'l

15.

TEST

PROCEDURE

(Cont'd.)

SELECTIVE

AMPLIFIER

ALIGNMENT

-

(Cont'd.)

2A.

Remove

amplifier

tubes

V2

and

V5.

Disconnect

voltmeter

and

connect

output

from

external

20

KC

source

to

this

same

point

(junction

of

C7

and

Rll)

in

plate

circuit

of

V2.

Reconnect

voltmeter

to

junction

of

C16

(0.05

fli)

and

R29

(68,000

ohms)

in

V4

plate

circuit.

2B.

Repeat

step

IE

except

adjust

trimmer

C9

across

toroid

coil

L2.

Change

the

valueoffixed

capacitor

C 10ifnecessary

to

center

C9

tuning

range.

2C.

Repeat

step

IF

except

adjust

the

valueofcathode

resistor

R20.

Set

older

instruments

(un-

modified

Serial

No.

1329

and

below)

foragainof17-1/2

to18db

instead

of19db,

±1/2

db.

2D.

Repeat

step

IG

except

adjust

potentiometer

R27.

2E.

Check

trimmer

setting

and

stage

gain

by

repeating

steps

2B

and

2C.

1£

a

change

is

made,

repeat

step

2D.

Replace

tubes

V2

and

V5.

3A.

Remove

amplifier

tubes

V4

ana.

V7.

Disconnect

voltmeter

and

connect

output

from

external

20

KC

source

to

this

same

point

(junction

of

Cl6

arid

R29)inthe

plate

circuit

of

V4.

Recon-

nect

voltmeter

to

junction

of

C24

(0.05

fli)

and

R45

(68,000

ohms)

in

V6

plate

circuit.

3B.

Repeat

step

IE

except

adjust

trimmer

C17acrosstoroid

coil

L3.

Change

the

valueoffixed

capacitor

Cl8ifnecessary

to

center

C17

tuning

range.

3C.

Repeat

step

IF

except

adjust

the

value

of

cathode

resistor

R36.

Set

older

instruments

(un-

modified

Serial

No.

1329

and

below)

foragainof17-1/2

to

18dbinstead

of19db,

±1/2

db.

3D.

Repeat

step

IG

except

adjust

potentiometer

R43.

3E.

Check

trimmer

setting

and

stage

gain

by

repeating

steps

3B

and

3C.

1£

a

change

is

made,

repeat

step

3D.

Replace

tubes

V4

and

V7.

4A.

Remove

amplifier

tube

V6.

Disconnect

voltmeter

and

connect

output

from

external

20

KC

source

to

this

same

point

(junction

of

C24

and

R45)inthe

plate

circuit

of

V6.

Reconnect

voltmeter

to

junction

of

C32

(0.05

fli)

and

R60

(68,000

ohms)

in

V8

plate

circuit.

4B.

Repeat

step

IE

except

adjust

trimmer

C25

across

toroid

coil

L4.

Change

the

value

of

fixed

capacitor

C26

if

necessary

to

center

Cl7

tuning

range.

4C.

Repeat

step

IF

except

adjust

the

value

of

cathode

resistor

R52.

Set

older

instruments

(un-

modified

Serial

No.

1329

and

below)

foragain

of19to

19-1/2

db

instead

of19db,

±1/2

db.

4D.

Repeat

step

lG

except

adjust

potentiometer

R58.

4E.

Check

trimmer

setting

and

stage

gain

by

repeating

steps

4B

and

4C.

1£

a

change

is

made,

repeat

step

4D.

Replace

tube

V6.

5.

Replace

bottom

plate

on

top

deck

and

reconnect

plugs

for

two

cables

connecting

top

and

lower

decks.

Turn

instrument

upr

ight.

6.

Balance

the

modulator

as

previously

explained

under

CALIBRATION

PROCEDURE.

Adjust

the

"V"

control

forareading

of5volts

on

the

VOLTS

calibration

meter.

Flip

switch

"S"

to

the

right.

7.

Set

HALF

BAND

WIDTH

control

to

"145",

tune

in

60

cps

and

settoa

reference

point

on

the

MILLIVOLTS

meter

with

the

"G"

control.

8.

Turn

HALF

BAND

WIDTH

control

to

"3D"

and

retune

foramaximum

reading

with

the

FINE

TUNING

control.

9.

Adjust

the

NEGATIVE

FEEDBACK

control

to

obtain

the

same

reference

reading

on

the

MILLI-

VOLTS

meter.

1£

the

NEGATIVE

FEEDBACK

control

is

between

"-15"

and

"+5",

the

selec-

tive

amplifier

is

correctly

aligned.

Repeat

alignment

procedure

until

this

test

can

be

passed.

10.

Place

instrument

in

its

cabinet

and

allow

to

operate

for

several

hours

before

proceding

with

the

HEAT

RUN

CHECK

that

follows.

1£

new

coils

have

been

installed,

instrument

should

be

operated

continually

for

at

least

24

hour

s.

Upto3or4

days

heat

runisre

commended.

16.

TESTPR

OCED

URE

(Cont

'd.

)

HEA

T RUNCHECK

-

1.

Allow

instrument

to

operate

for

several

hours.

Check

the

position

of

the

NEGATIVE

FEED-

BACK

control

as

directed

in

steps

6, 7,

8,

and9of

the

SELECTIVE

AMPLIFIER

ALIGNMENT

procedure

and

record

the

control

setting.

2.

Turn

instrument

off

and

letifcool

over

night.

Repeat

last

step

when

instrument

has

been

on

forafew

minutes

and

again

record

the

NEGATIVE

FEEDBACK

control

setting.

3.

Repeat

steps1and2until

the

instrument

is

stabilized

as

indicated

by

the

NEGATIVE

FEED-

BACK

control

not

requiring

excessive

adjustment

between

"hot"

and

"cold"

operating

temper-

atures.

The

adjustment

required

may

drift

outside

the

limits

of

this

control.

In

this

case,

the

ampli-

fier

should

again

be

aligned

and

the

unit

put

on

heat

run.

This

realignment

may

be

required

a

third

time.

If

the

instrument

will

not

stabilize,

it

may

be

necessary

to

replace

one

or

more

of

the

toroid

coils.

The

defective

coil

can,

in

most

cases,

be

located

during

realignment

of

the

selective

amplifier.

Change

the

coil

in

the

amplifier

section

that

requires

excessive

retuning

and

re-

adjustment

of

the

internal

feedback

potentiometer

(R8,

R27, R43,

or

R58).

Once

the

instrument

is

stabilized

it

is

ready

for

the

final

test.

FINAL

TEST

-

1.

Check

regulated

output

voltage

in

power

supply

as

directed

in

the

PRELIMINAR

Y

TESTS

&:

ADJUSTMENTS

section

of

this

manual.

2.

Check

oscillator

voltage

as

directed

in

PRELIMINARY

TESTS

&:

ADJUSTMENTS.

3.

Check

oscillator

stability

and

response

to

line

voltage

change

as

follows:

A.

Applya400

cps,

1/2

volt

signal

to

input

terminals

and

tune

instrument

to

same

frequency

with

HALF

BAND

WIDTH

control

setat"145".

B.

Adjust

MILLIVOLTS

meter

to

full

scale

with

control

"G".

C.

Turn

HALF

BAND

vvIDTH

control

to

"30"

and

repeak

signal

with

FINE

TUNING

control.

Adjust

NEGATIVE

FEEDBACK

control

forafull

scale

MILLIVOLTS

meter

reading.

D.

Turn

the

line

voltage

down

to

105

volts

with

the

variable

transformer.

The

meter

read-

ing

normally

drops

to

half

scale.

When

the

meter

has

stopped

drifting,

retune

with

the

FINE

TUNING

control.

The

meter

should

read

within

15%offull

scale.

A

change

of

greater

than

15%isusually

caused

byaweak

tube.

Tubes

VI05

and

VI06

in

the

local

oscillator,

as

well

as

tubes

V9

and

VIOinthe

meter

circuit

should

be

checked

fir

st.

4.

Repeat

the

SELECTIVE

AMPLIFIER

ALIGNMENT

procedure

asafinal

selective

amplifier

alignment.

5.

With

no

input

to

instrument,

set

frequency

dial

to

midscale

and

the

SET

TO

100

dial

to

zero.

Set

the

mechanical

zero

on

the

MILLIVOLTS

meter

to

zero.

The

instrument

must

beatnor-

mal

operating

temperature

when

this

adjustment

is

made.

6.

Balance

the

modulator

as

explained

in

steps1through

11ofCALIBRA

TION

PROCEDURE.

Check

control

"C"

butterfly

capacitor,

CI07,

to

see

thatitis

meshed

equally

on

both

sides.

An

unbalanced

setting

of

this

capacitor

is

an

indication

that

modulator

tubes

Vl02

or

VI03

are

unbalanced,

modulation

transformer

(T101)isdefective,

or

there

are

other

defective

parts

in

the

modulator

circuit.

Refer

to

the

TROUBLE

SHOOTING

section

of

this

manual.

7.

Check

for

carrier

leakage.

Balance

modulator

with

HALF

BAND

WIDTH

control

at

"145

",

METER

SENSITIVITY

control

at

"500",

and

frequency

dial

at

"0".

Turn

METER

SENSITIV-

1Tyto"25",

rebalance

modulator,

turn

control

back

to

"500",

and

note

MILLIVOLTS

meter

reading.

Carrier

leakage

caused

by

the

20

KC

signal

from

the

local

oscillator

feeding

through

the

power

supply

into

the

top

deck

will

result

inahigher

MILLIVOLTS

meter

reading.

Cor-

rective

steps

are

given

in

the

TROUBLE

SHOOTING

section

of

this

manual.

•

..

....

....

-.

l>'

o

.......

U1
U1

..

17.

TEST

PROCEDURE

(Cont1d.)

FINAL

TEST-(Cont'd.)

8.

Check

for

hum

as

follows:

A.

Balance

the

modulator.

B.

Set

METER

SENSITIVITY

control

to

"500"

and

HALF

BAND

WIDTH

control

to

"145".

C.

Set

the

sub-panel

meter

to5volts

with

control

"V".

Flip

lever

switch

"S"tothe

right.

D.

Tune

instrument

at60cps

foramaximum

MILLIVOLTS

meter

reading.

Adjust

control

"G"toobtainafull

scale

MILLIVOLTS

meter

indication.

E.

Turn

HALF

BAND

WIDTH

control

to

"30"

and

retune

instrument

foramaximum

MILLI-

VOLTS

meter

reading.

Adjust

NEGATIVE

FEEDBACK

control

to

obtainafull

scale

MILLIVOLTS

meter

reading.

F.

Flip

lever

switch

"5"tothe

left

(vertical

position)

and

turn

the

METER

SENSITIVITY

switch

to

"1".

G.

Balance

hum

potentiometer

(R159)inlower

deck

foraminimum

MILLIVOLTS

meter

reading.

The

reading

obtained

should

notbemore

than

0.08

millivolts.

H.

Retune

instrument

to

120

cps

and

then

180

cps.

The

MILLIVOLTS

meter

reading

again

should

notbemore

than

0.08

millivolts.

Refer

to

the

TROUBLE

SHOOTING

notes

on

hum

removal.

9.

Check

resonance

curves

as

follows:

A.

Check

resonance

curve

fora60

cps

"hump".

Set

HALF

BAND

WIDTH

control

to

"30";

METER

SENSITIVITY

at

"500";

METER

MULTIPLIER

at

".5";

SET

TO

100at"100";

and

connecta400

cps,

1/2

volt,

external

source

to

the

input

terminals.

Tune

instru-

ment

to

400

cps

and

adjust

control

"G"

forafull

scale

MILLIVOLTS

meter

deflection.

Gradually

shift

the

external

oscillator

frequency

and

switch

the

METER

SENSITIVITY

control

counterclockwise

to

maintain

a

MILLIVOLTS

meter

reading.

The

meter

indication

should

drop

gradually.

When

the

oscillator

is

60

cps

away

from

400

cps,

the

gradual

drop

may

showahesitation

orasmall

rise

whichisan

indication

ofa60

cps

"hump"

in

the

resonance

curve.

The

external

oscillator

must

be

tuned

on

both

sides

of

400

cps

for

this

test.

Refer

to

TROUBLE

SHOOTING

section

of

this

manual

for

methods

of

eliminating

this

"hump".

Plot

the

resonance

curve

on

the

broad

sample

curve

given

in

Fig.

8.

The

plotted

curve

should

fall

within

the

two

outside

lines

of

sample

curve.

Set

instrument

controls

and

connect

external

signal

source

asinstep

9A

except

set

HALF

BAND

WIDTH

control

at

"145".

Peak

instrument

forafull

scale

MILLIVOLTS

meter

reading

at

400

cps.

Set

external

oscillator

to

420,

460,

520,

545,

and

700

cps.

Record

millivolt

reading

obtained

at

each

frequency.

Repeat

this

same

process

after

recording

the

readings

obtained

by

tuning

the

external

oscillator

to

380,

340,

280, 255,

and

100

cps.

If

the

plotted

curves

fall

outside

the

sample

curve

limits,

it

will

be

necessary

to

change

the

value

of

anyone

or

all

four

resistors

R18,

R34,R74,

andR77

across

the

toroid

coils.

Increasing

a

resistor

value

will

sharpen

the

resonance

curves

in

both

broad

("145")

and

sharp("30")

HALF

BAND

WIDTH

control

positions.

Adjustment

of

the

broad

curve

must

be

completed

before

attempting

adjustment

of

the

sharp

tuning

curve.

B.

1.t'l

I."')

-

0

ri'f

-

.

..,.

-

N

0
0

<:

0
0

C.

<""\

The

selective

amplifier

must

be

realigned

after

changing

anyofthese

four

resistors.

D.

Set

HALF

BAND

WIDTH

control

to

"30"

(sharp)

and

plot

resonance

curve,

using

the

pro-

cedure

given

in

step

9B

except

take

readings

at

10,

20,

30,

40,

50,

60,

and

70

cps

above

and

below

400

cps.

Particular

attention

should

be

giventothe

frequencies

of

340

and

460

cpstobe

sure

thata"hump"

does

not

appear

as

explained

in

step

9A.

18.

..

TEST

PROCEDURE

(Cont'd.)

FINAL

TEST-(Cont'd.)

9D.

(Cont'd.)

If

the

plotted

curves

fall

outside

the

sample

curve

limits,

it

will

be

necessary

to

change

the

value

of

either

or

both

resistors

R75andR76inthe

feedback

circuits

of

the

two

center

stages.

Decreasing

the

value

of

these

resistors

will

sharpen

the

resonance

curve.

The

selective

amplifier

must

be

realigned

after

changing

either

resistor

values.

Changing

either

or

bothofthese

resistor

values

will

not

affect

the

broad

tuning

curve.

If

the

two

sides

of

the

resonance

curve

are

not

symmetrical,

repeat

this

step

after

very

carefully

peaking

the

instrument

to

400

cps

with

the

MILLIVOLTS

meter.

Refer

to

the

TROUBLE

SHOOTING

section

of

this

manual

if

the

resonance

curve

is

still

not

symmet-

rical.

10.

Check

harmonic

distortion

in

the

300Aasfollows:

A.

Balance

the

modulator,

set

HALF

BAND

WIDTH

control

to

"145",

and

switch

METER

SENSITIVITY

to

"500".

Connect

an

external

signal

source

with

pure

wave

filter

to

input

terminals

and

adjust

to

deliver

a

0.5

volt

signal

at

approximately

1600

cps.

The

external

signal

source

may

have

as

high

as

1.00/0

distortion

provided

a

pure

wave

filter

is

used

between

this

source

and

the

300A

input.

Refer

to

INSTR

UMENTS

REQUIRED

FOR

TEST

PROCEDURE

at

the

beginning

of

this

TEST

PROCEDURE

section.

B.

Peak

the

300Atothe

input

signal

and

adjust

the

MILLIVOLTS

meter

to

full

scale

with

control

"G".

Retune

instrument

to

the

second

harmonic

(32.00

cps)

and

set

METER

SENSITIVITY

switch

to

"1".

C.

Adjust

potentiometer

Rl17

in

the

grid

circuit

of

balanced

modulator

tubes

(Vl02

and

Vl03)

foraminimum

MILLIVOLTS

meter

reading.

Rebalance

the

modulator

and

again

adjust

Rl17

foraminimum

reading.

The

remaining

MILLIVOLTS

meter

reading

should

not

be

more

than

0.2

millivolts.

This

reading

is

an

indication

of

input

signal

distortion

by

the

300A.

Retune

the

300A

to-

the

third

harmonic

(4800

cps)

and

note

the

MILLIVOLTS

meter

read-

ing.

This

reading

should

again

not

be

more

than

0.2

millivolts.

D.

Repeat

steps

lOA

and

lOB

with

external

signal

source

tuned

to

approximately

6300

cps

and

check

second

harmonic

(12,600

cps)

only.

The

MILLIVOLTS

meter

readi~g

obtained

should

notbegreater

than

0.2

millivolts.

11.

Check

HALF

BAND

WIDTH

variable

selectivity

control

as

follows:

A.

Connecta400

cps,

0.5

volt,

sine

wave

signal

to

the

300A

input

terminals.

Tune

instru-

ment

foramaximum

reading

with

HALF

BAND

WIDTH

control

at

"145".

Set

MILLI-

VOLTS

meter

toareference

point

of

".8"

with

control

"G".

The

METER

SENSITIVITY

switch

should

be

on

"500".

B.

Set

HALF

BAND

WIDTH

control

to

"30"

and

repeak

the

instrument

with

the

FINE

TUNING

control.

Adjust

NEGATIVE

FEEDBACK

controlfor

same"

.8"

MILLIVOLTS

meter

ref-

erence

reading.

C.

Turn

the

HALF

BAND

WIDTH

controlfor

a

maximum

reading

on

the

MILLIVOLTS

meter

and

repeakthesignalwith

the

FINE

TUNING

control.

The

resultant

MILLIVOLTS

meter

read-

ing

should

benogr

eater

than"1•0".Ifthe

readingifoff

scale,

refer

to

the

TR

OUB

LE

SHOOTING

section

of

this

manual.

12.

Check

MILLIVOLTS

meter

tracking

as

follows:

A.

Check

mechanical

zero

as

described

in

FINAL

TEST

step

5.

B.

Set

the

300Atoread

voltages

accurately

as

explained

in

steps

26A

and

26B

of

PROCED-

URE

FOR

CALIBRATION.

Introduce

a

400

cps

signai

and

check

MILLIVOLTS

meter

tracking

against

a

meter

with

known

calibration

accuracy.

The

300A

voltmeter

readings

should

be

within

±20/0ofthe

full

scale

reading.

13.

Check

instrument

sensitivity

as

follows:

A.

Set

METER

SENSITIVITY

at

"500",

control

"G"

full

clockwise,

SET

TO

100

control

full

clockwise,

METER

MULTIPLIER

at

".5",

and

HALF

BAND

WIDTH

control

at

"145".

..

TEST

PROCEDURE

(Cont'd.)

FINAL

TEST-(Cont'd.)

13.

(Cont'd.)

19.

B.

Connect

400

cps

from

an

external

oscillator

to

input

terminals

and

tune

300A

foramaxi-

mum

MILLIVOLTS

meter

reading.

Adjust

external

os

cillator

forafull

scale

MILLI-

VOLTS

meter

reading.

The

input

signal,

as

measured

at

the

input

terminals

byanac-

curate

external

voltmeter,

will

normally

be

0.25

volt

or

less.

If

external

signal

is

0.5

volt

or

less,

sensitivity

is

satisfactory.

See

TROUBLE

SHOOTING

section

if

input

volt-

ageistoo

high.

14.

Check

main

tuning

dial

frequency

calibration

as

follows:

A.

Set

frequency

dial

at

"0"

and

FINE

TUNING

control

with

knob

indicator

straight

up.

Tune

control

"F"

foramaximum

MILLIVOLTS

meter

reading

which

will

indicate

that

the

in-

ternal

oscillator

frequency

is

20

KC.

Rotor

plates

of

"F"

control

trimmer

should

be

approximately

half

meshed

with

stator

plates

when

tunedto20

KC.

If

they

are

not,

orifinternal

oscillator

cannot

be

tuned

to

20

KC

with

control

"F",

it

will

be

necessary

to

adjust

variable

capacitor

Cl23

(See

Fig.

4).

If

necessary,

the

values

of

fixed

capacitors

Cll2

and

Cll3

may

be

adjusted.

In

older

instruments

having

fixed

capacitors

Cl12

and

Cll3

only,

adjustment

can

be

made

only

by

changing

these

capacitor

values.

When

oscillator

isonfrequency

in

approximate

center

of

tuning

range

for

control

"F",

balance

the

modulator.

Do

not

change

setting

of

control

"F"

or

the

FINE

TUNING

con-

trol

for

remaining

portion

of

this

step.

Check

frequency

dial

calibration

with

an

external

oscillator

andafrequency

standard

or

other

frequency

measuring

device

connected

to

the

300A

input

terminals.

Adjust

main

tuning

dial

foramaximum

MILLIVOLTS

meter

indication

and

note

the

dial

reading.

Re-

peat

this

processacross

the

instrument

frequency

range.

Frequency

dial

calibration

should

be

within

±3%atfrequencies

of

100

cps

or

higher

and

±5%atfrequencies

below

100

cps.

To

correct

poor

frequency

dial

tracking,

pad

Rl38

and

Rl39

precision

resistors

and

re-

adjust

variable

capacitor

Cl23

or

change

fixed

capacitors

CIl2

and

Cll3

to

bring

oscil-

lator

on

frequency.

Series

or

parallel

resistor

pads

may

be

used

depending

upon

the

tracking

error

to

be

corrected.

Increasing

either

or

both

these

resistor

values

will

de-

creaseos

cillator

frequency.

B.

Check

andifnecessary

adjust

oscillator

injection

voltage

at

VI02

and

Vl03

cathodes

as

directed

in

step2of

PRELIMINARY

TESTS&ADJUSTMENTS.

Turn

frequency

dial

from

toptobottom

while

measuring

cathode

injection

voltage

of

Vl02

and

VI03.

Ii

injection

voltage

is

not

constant,

reset

variable

capacitor

C123

and

bring

oscillator

on

frequency

with

control

"F".

If

range

ofC123isnot

wide

enough

or

C

123isnotina

particular

instrument,

change

capacity

ratio

of

fixed

capacitors

C

112

and

Cl13.

Increase

the

capacity

of

one

while

decreasing

the

capacity

of

the

other

an

equal

amount.

The

capacity

change

required

must

be

experimentally

determined.

Oscillator

injection

voltage

may

be

adjusted

foraslight

rise

at

topofdial

to

compensate

instrument

frequency

respons

e.

15.

Check

frequency

response

as

follows:

A.

Set

HALF

BAND

WIDTH

control

to

"145",

connect

external

voltrr.eter

and

audio

signal

generator

to

300A

input

terminals,

and

adjust

for

an

input

of

0.5

voltat100

cps.

Tune

forapeak

MILLIVOLTS

meter

reading

and

adjust

control

"G"

forareference

reading

of

0.9

on

the0to1.0

MILLIVOLTS

meter

scale

with

METER

SENSITIVITY

setto"500".

B.

Tune

generator

and

300Ato1

KC,

10

KC,

and

16

KC

while

maintaining

a

contstant

input

voltage.

External

voltmeter

must

be

flat

over

this

frequency

range.

The

MILLIVOLTS

meter

readings

should

not

vary

from

the

reference

point

by

more

than

±2%offull

scale.

Correct

a

slight

error

by

adjusting

the

internal

oscillator

frequency

response

as

explained

in

step

14B.

To

correct

a

large

error,

see

the

TROUBLE

SHOOTING

section.

20.

TEST

PROCEDURE

(Cont'd.)

FINAL

TEST-(Cont'd.)

16.

Check

voltage

calibration

as

follows:

A.

Balance

the

modulator,

set

HALF

BAND

WIDTH

control

to

"145",

set

METER

SENSI-

TIVITY

to

"500",

turn

SET

TO

100

control

full

clockwise,

and

set

METER

MULTIPLIER

control

to

" •

5".

B.

Intro:luce

a

measured

400

cps

voltage

of

exactly

0.5

volt

into

the

300A

input

terminals.

Tune

forapeak

and

set

MILLIVOLTS

meter

to

full

scale

with

"G"

control.

C.

Turn

control

"V"

full

counterclockwise

and

adjust

the

mechanical

zero

of

the

VOLTS

meter.

D.

Flip

switch

"S"tothe

right

and

adjust

control

"V"

forareading

of5volts

on

the

VOLTS

meter.

E.

Tune

instrument

forapeak

MILLIVOLTS

meter

reading

at

60

cps.

00

NOT

CHANGE

THE

"G"

CONTROL

SETTING.

F.

The

MILLIVOLTS

meter

reading

should

be

full

scale.

If

not,

adjust

the

60

cps

signal

forafull

scale

reading

by

padding

either

RI06

orR107inthe

voltage

divider.

Maintain

a

VOLTS

meter

reading

of5volts

with

control

"V"

and

pad

RI06

or

RI07

to

obtain

a

full

scale

MILLIVOLTS

meter

reading.

G.

Recheck

forafull

scale

reading

at

400

cps

asinstepBexcept

do

not

change

the

"G"

control

setting.

H.

Repeat

stepsBthrough

G

untilafull

scale

reading

is

obtained

for

steps

F

andGby

set-

ting

control

"V"

for5volts

and

tuning

forapeak

MILLIVOLTS

meter

reading.

17.

Check

the

METER

SENSITIVITY

control

as

follows:

A.

Set

METER

MULTIPLIER

to

".5",

SET

TO

100

control

full

clockwise,

HALF

BAND

WIDTH

control

to

"145",

and

METER

SENSITIVITY

control

to

"500".

B.

Connect

output

terminals

ofaprecision

attenuator

to

300A

input

terminals.

Use

the

cor-

rect

value

of

attenuator

load

as

specified

by

the

attenuator

manufacturer.

This

load

may

be

connected

across

the

300A

input

terminals.

C.

Couplea400

cps

source

to

the

attenuator

input

and

adjust

both

attenuator

and

source

to

provide

a

0.5

volt

(500

millivolts)

input

signal

to

the

300A.

The

resulting

signal

level

at

the

attenuator

input

must

be

maintained

constant

for

the

balance

of

this

procedure.

D.

Peak

the

300A

foramaximum

MILLIVOLTS

meter

indication

and

set

control

"G"

for

a

full

scale

reading

of

500

millivolts.

DO

NOT

CHANGE

THE

SETTING

OF

CONTROL

"G"

FOR

THE

BALANCE

OF

THIS

TEST.

..

E.

Maintain

a

constant

attenuator

input

level.

Refer

to

the

table

on

the

right.

Adjust

the

attenuator

to

introduce

amount

of

attenua-

tion

given

in

column

one,

set

the

METER

SENSITIVITY

control

to

the

position

given

in

column

two,

and

adjust

the

FINE

TUNING

control

foramaximum

MILLIVOLTS

meter

indication.

In

each

case,

the

resulting

MILLIVOLTS

meter

reading

should

be

with-

in

±2%offull

scale.

This

check

is

accurate

only

when

the

input

level

is

maintained

constant

andaproperly

terminated

precision

attenuator

is

used.

Attenuation

METER

SENSITIVITY

in

db

Control

Setting

0

·

·

·

·

· · ·

500

6

···

·

···

250

14

· · · ···

·

100

20

·

·

·

· · ·

50

26

··· · · · ·

25

34

··· · · · ·

10

40

· · ·

·

· · ·

5

46

·

· ·

· · · ·

2.5

54

· · · ·

·

·

·

1

The

external

audio

oscillator,

ac

voltmeter,

attenuator,

and

300A

should

be

grounded

through

the

input

test

cable

only.

One

side

of

the

audio

oscillator

output

cable

should

be

grounded

to

oscillator

chassis

at

the

output

terminals.

A

ground

loop

may

cause

erroneous

readings

when

measuring

low

ac

voltages.

N

o

o

«

o
o

M

21.

TEST

PROCEDURE

(Cont'd.)

FINAL

TEST

-

(Cont'd.)

18.

Check

the

METER

MULTIPLIER

control

as

follows:

A.

Set

METER

MULTIPLIER

to

".5",

SET

TO

100

control

full

clockwise,

HALF

BAND

WIDTH

control

to

"145",

and

METER

SENSITIVITY

control

to

"500".

B.

Apply

exactly

0.5

volt

(500

millivolts)

at

approximately

400

cpstothe

300A

input

ter-

minals.

Peak

the

300A

foramaximum

MILLIVOLTS

meter

indication

and

set

control

"G"

forafull

scale

reading

of

500

millivolts.

DO

NOT

CHANGE

THE

SETTING

OF

CONTROL

"G"

FOR

THE

BALANCE

OF

THIS

TEST.

C.

Set

the

METER

MULTIPLIER

and

METER

SENSITIVITY

controls

to

the

positions

given

in

the

following

chart

and

note

the

MILLIVOLTS

meter

reading

which

should

beasin-

dicated

in

this

same

chart.

Maintainaconstant

input

signal

level.

METER

MULTIPLIER

METER

SENSITIVITY

MILLIVOLTS

Meter

Control

Setting

Control

Setting

Reading

• 5

500

Set

level

to

full

scale

•

5

50

Full

Scale,

±l%.

50

5

Full

Scale,

±l%.

500

1

Half

Scale,

±2%.

19.

In

some

older

instruments,

random

noise

may

causeaslight

erratic

movement

of

the

MILLI-

VOLTS

meter

pointer.

Installation

of

resistor

R73(220

ohms,

±10%,1watt)

and

capacitor

C36

(500~,

15

vdcw,

electrolytic)

in

the

voltmeter

circuit

will

eliminate

this

erratic

move-

ment.

This

network

may

be

added

on

the

top

deck

behind

the

MILLIVOLTS

meter

onatie-

point

installed

for

that

purpose.

These

components,

when

factory

installed,

are

mounted

on

the

underside

of

the

top

deck.

20.

Install

"CALIBRATION

PROCEDURE"

labels

on

the

inside

of

the

sub-panel

doorifthey

are

not

alreaay

there.

These

labels

are

available

asaset

from

the

factory

under

-hp-

Stock

No.

3A-43A.

21.

Give

the

instrument

a

complete

mechanical

inspection.

Check

for

missing

or

loose

screws,

poor

solder

connections,

and

missing

or

loose

shields.

Install

bottom

plates

and

replace

in

cabinet.

22.

The

metal

bottom

plate

was

fastened

to

the

inside

of

the

cabinet

in

some

older

instruments.

Solderaflexible

lead

from

this

platetoa

solder

lugonthe

backofthe

lower

deck.

This

is

necessary

to

reduce

lower

deck

hum

pick

up.

In

later

instruments,

this

plateisfastened

directly

to

the

chassis

bottom.

23.

Replace

ventilating

screen

over

instrument

back.

Turn

instrument

on

and

letitrun

for

a

few

hours.

Check

NEGATIVE

FEEDBACK

control

setting

from

time

to

time

during

this

time.

No

great

change

should

be

required

in

this

setting

as

explained

under

HEAT

RUN

CHECK

in

this

.same

section.

,~

LQ

-

o

r"'l

-

-

-

N

o
o

<

o

o

r"'l

23.

CIRCUIT

MODIFICATIONS

GENERAL

-

The

circuit

modifications

that

follow

provide

greater

instrument

stability;

longer

component

life;

ease

of

adjustment,

testing,

and

repair;

and

better

manufacturing

procedures.

Electrical

perfor-

mance

specifications

of

the

Model

300A

have

not

changed

and

an

older

instrument

will

provide

the

same

results

asanew

instrument.

If

an

older

instrument

is

functioning

properly,

there

is

no

rea-

sontomake

any

circuit

modifications.

WARNING

MAJOR

MODIFICATIONS

SHOULDBEATTEMPTED

ONLY

WHEN

THE

NECESSARY

TEST

EOUIPMENT

IS

AVAILABLE

FOR

FINAL

TESTING

AND

ADJUSTMENTOFTHE

MODIFIED

INSTRUMENT.

INSTRUMENT

REOUIREMENTS

FOR

FINAL

TESTING

ARE

GIVENINTHE

TEST

PROCEDURE

SEC-

TION

OF

THIS

MANUAL.

Instruments

with

Serial

No.

1330

and

above

require

no

top

deck

modifications.

Instruments

with

Serial

No.

1610

and

above

require

no

modifications

in

either

the

toporbottom

decks.

The

top

deck

in

instruments

with

Serial

No.

1610

and

above

is

the

same

as

thatininstruments

with

Serial

No.

1330

and

above.

With

certain

exceptions

in

early

instruments

as

noted,

the

modifications

that

follow

will

convert

any

Model

300Asothat

the

top

deck

hasacircuit

equivalent

to

instruments

with

Serial

No.

1330

or

above

and

the

lower

deck

hasacircuit

equivalent

to

instruments

with

Serial

No.

1610orabove.

Components

necessary

for

making

circuit

modifications

are

available

from

Hewlett-packard.

How-

ever,

the

quantity

required

will

vary

depending

upon

the

ageofthe

particular

instrument

involved.

IMPORTANT

SCHEMATIC

NOTICE

ALL

CIRCUIT

REFERENCES

ARE

FOR

SCHEMATIC

DIAGRAMS

GIVENINFIGURES3OR4UN-

LESS

OTHERWISE

NOTED.

TOP

DECK

MODERNIZING

PROCEDURE

-

The

following

circuit

changes

will

convert

top

decks

in

all

instruments

with

Serial

No.

1329orbe-

low

into

the

circuit

giveninFig.

3.

A

complete

listofparts

for

this

modernization

follows

the

last

stepinthis

procedure.

There

are

some

instruments

in

the

field

havingacombination

of

toroid

coils

for

the

first

and

fourth

selective

amplifier

stages

and

solenoid

type

coils

for

the

second

and

third

stages.

These

solenoid

type

coils

are

wound

onaround

bobbin.

Instruments

with

this

coil

combination

usually

have

large

rectangular

shaped

coil

shields.

Such

instruments

should

be

returned

to

the

factory

as

field

mod-

ernization

is

not

practical.

1.

Remove

the

four

toroid

coil

shield

cans.

Install

one

watt,

precision,

carbon

film,

resistor

of

479,

000

ohms

forR74,

R18,

R34,

andR77inparallel

with

Ll,

L2, L3,

and

L4

respec-

tively.

Add

this

resistor

to

all

four

toroid

coils.

Any

other

resistors

found

across'acoil

must

be

removed.

Replace

coil

shields

by

pressing

them

firmly

over

base

on

chassis.

2.

In

some

older

instruments

it

will

be

necessary

to

replace

anyone

or

all

four

toroid

coils.

Drift

will

causealoss

in20KC

selective

amplifier

gain.

It

will

be

necessary

to

advance

the

NEGATIVE

FEEDBACK

control

farther

and

farther

clockwise

to

obtain

sufficient

gain

when

the

HALF

BAND

WIDTH

control

is

setto"30".

Amplifier

alignment

will

be

required

when

the

NEGATIVE

FEEDBACK

control

adjustment

limit

is

reached.

If

the

drift

reoccurs

repeatedly

after

amplifier

alignment,

coil

replacement

is

required.

Refer

to

TROUBLE

SHOOTING

section

andtoHEAT

RUN

CHECK

in

the

TEST

PROCEDURE

section

for

tests

to

determine

if

coil

replacement

is

necessary.

3.

Install

resistors

of

80,000

ohms,

±l%,1watt

(-hp-

Stock

No.

31-80K)

forR10

and

R59inthe

negative

feedback

circuits

for

VI

and

V7

respectively.

Install

resistors

of

56,000

ohms,

±l%,

1

watt

(-hp-

Stock

No.

31-56K)

for

R28

and

R44inthe

negative

feedback

circuits

for

V3

and

V5

respectively.

The

precision

resistors

available

under

the

-hp-

Stock

numbers

given

a-

bove

are

the

only

ones

recommended

for

this

replacement.

4.

Install

-hp-

Stock

No.

24-68K

resistors

(68,000

ohms,

±lO%,1watt,

composition)

for

RIl,

R29,

R45,

and

R60inthe

negative

feedback

networks

for

all

four

stages.

2.4.

CIRCUIT

MODIFICATIONS

(Cont'd.)

TOP

DECK

MODERNIZING

PROCEDURE

-

(Cont'd.)

5.

Install

-hp-

Stock

No.

3l-2M

resistors

(2.0

megohms,

±l%,1watt,

carbon

film)

for

R9

and

R57inthe

positive

feedback

circuits

of

VI

and

V7

respectively.

Replace

R4

and

R5l

(shown

in

Fig.5as

being

in

series

with

R9

and

R57)

with

wire

jumpers.

6.

Install

-hp-

Stock

No.

3l-1.63M

resistors

(1.63

megohms,

±l%,1watt,

carbon

film)

for

R26

and

R42inthe

feedback

circuits

for

V3

and

V5

respectively.

Install

-hp-

Stock

No.

23-l50K

resistors

(150,000

ohms,

±lO%, 1/2watt,

composition)

forR75

andR76inseries

with

R26

and

R42

respectively.

These

1/2

watt

resistors

should

be

temporarily

mounted

since

their

value

will

probably

be

changed

during

alignment

of

the

selective

amplifier

system.

7.

ReplaceR1,R17,

R33,

and

R50

with

-hp-

Stock

No.

3l-830K

precision

resistors

(830,

000

ohms,

±l%,1watt,

carbon

film).

These

resistors

are

in

the

grid

circuits

of

VI,

V3,

V5,

and

V7

respectively.

8.

Replace

R3,

R2l,

R37,

and

R53

with

-hp-

Stock

No.

31-5000

precision

resistors

(5000

ohms,

±l%,1watt,

carbon

film).

These

resistors

are

in

the

cathode

circuits

of

VI,

V3,

V5,

and

V7

respectively.

9.

Replace

R2,

R20,

R36,

and

R52inthe

cathode

circuits

of

VI,

V3,

V5,

and

V7

respectively

with

-hp-

Stock

No.

31-900

precision

resistors

(900

ohms,

±l%,1watt,

carbon

film).

Shunt

each

of

these

four

resistors

with

an

-hp-

Stock

No.

24-3900

resistor.

These

shunt

resistors

(3900

ohms,

±lO%,1watt,

composition)

should

be

temporarily

installed

as

their

final

values

are

determined

during

alignment

and

adjustment

of

the

selective

amplifier

stages.

10.

Install

C37, C38, C39,

and

C40

(10

fl~,

±100/0,

500

vdcw,

mica,

-hp-

Stock

No.

14-10)

in

parallel

with

Rll,

R29, R45,

and

R60

respectively.

11.

Replacement

of

NEGATIVE

FEEDBACK

and

HALFBAND

WIDTH

four

gang

control

potentio-

meters

and

their

shielded

connecting

cables

is

recommended

for

complete

modernization.

This

is

particularly

important

in

instruments

with

shielded

cables

that

do

not

have

an

insu-

lating

outer

cover.

12.

In

instruments

with

Serial

No.

1106orbelow,

installR73

resistor

(220

ohms,

±lO%,1watt)

in

series

with

the

MILLIVOLTS

meter

movement.

Connect

C36

(500~,

15

vdcw

electrolytic)

capacitor

in

parallel

with

this

series

combination.

The

circuit

before

this

modification

is

,showninFig.

7A

and

afterwards

in

Figs'.3and

7B.

This

network

is

mounted

on

the

top

deck

behind

the

MILLIVOLTS

meter

onatiepoint

installed

for

this

purpose.

The

addition

of

this

network

minimizes

meter

pointer

unsteadines

s

due

to

random

noise.

These

components

when

factory

installed,

are

mounted

on

the

underside

of

the

top

deck.

PARTSREQUIRED

FOR

COMPLETE

MODERNIZATION

OFATOP

DECK

-

The

exact

number

of

parts

required

will

be

dependent

upon

instrument

age.

Maximum

quantities

are

given

below.

v.

c

c

:x:.
c
c

[\,

DESCRIPTION

Resistors,

Precisionj

fixed,

leads,

±l%,1watt,

900

ohms

••

5000

ohms

56,000

ohms

80,000

ohms

479,000

ohms

830,

000

ohms

1.63

megohms.

2.0

megohms

• •

carbon

fil

m,

axial

QUANTITY

4
4

2
2

4

4

2
2

-hp-

STOCK

NO.

31-900
31-5000
3l-56K
3l-80K
3l-479K
3l-830K
3l-1.63M
3l-2M

....

....

.....

v.

c

.....

lJ
lJ

Resistorj

fixed,

composition,

150,000

ohms,

±lO%,1/2

watt

2

23-l50K

25.

CIRCUIT

MODIFICATIONS

(Cont'd.)

PARTS

REQUIRED

FOR

COMPLETE

MODERNIZATION

OFATOP

DECK-(Contrd.)

DESCRIPTION

Resistors;

fixed,

composition,

±lO%,

220

ohms

••

3900

ohms

68,

000

ohms

• • • •

Capacitor;

fixed,

mica,

10

flfli,

±lO%,

500

vdcw

Capacitor;

fixed,

electrolytic,

tubular,

500

1Ji,

15

vdcw

••••••••

watt,

QUANTITY

1

4
4

4

-hp-

STOCK

NO.

24-220
24-3900
24-68K

14-10

18-5

NEGATIVE

FEEDBACK

and

HALF

BAND

WIDTH

control

assemblies

with

shielded

and

insulated

connecting

harness

Toroid

coil

tuned

circuit

assembly;

20

KC

BOTTOM

DECK

MODIFICATION

PROCEDURE

-

4

3A-15

3A-62

U"\
U"\

.....

o

~

........

.....

-

Modifications

that

follow

are

divided

into

separate

procedures

since

it

may

not

be

necessary

or

desirable

to

incorporate

all

modifications

unless

required.

After

some

modifications

have

been

completed,

little

or

no

instrument

adjustment

is

required

while

after

other

modifications

extensive

instrument

adjustments

are

required.

Instrument

age

will

determine

parts

requirements

foraparticular

modification.

All

possible

parts

required

are

identified

by

-hp-

stock

number

as

well

asacomplete

description.

Determine

parts

requirements

by

reading

throughamodification

while

referring

to

i.nstrument

tobechanged.

Parts

required

can

then

be

secured

from

-hp-

oralocal

source.

MODIFICATION

TO

REDUCE

CARRIER

LEAKAGE

-

When

incorporated

in

instruments

with

Serial

No.

1369orbelow,

this

modification

will

pro-

vide

reduced

carrier

leakage.

Step7of

the

FINAL

TEST

procedure

gives

the

method

of

checking

carrier

leakage.

Instruments

with

Serial

No.1370

and

above

had

this

modification

included

dur

ing

manufacture.

This

modification

can

be

incorporated

at

any

time

and

requires

no

special

instrument

adjust-

ments

following

completion.

Any

instruments

withasingle

three

section

capacitor

for

C 12

5,

C126,

and

C127

should

have

this

modification

incorporated

before

or

when

replacement

of

this

electrolytic

is

necessary.

Basically

three

mechanical

changes

are

made

in

the

instrument

wiring

when

incorporating

this

revision.

Coupling

in

the

common

electrolytic

capacitor

for

Cl25,

Cl26,

and

Cl27

is

eliminated

in

older

instruments

by

installing

separate

capacitors.

Leads

carrying

B+

are

eliminated

in

any

cabling

crossing

the

front

of

the

chassis.

Resistor

Rl54

is

moved

to

a

new

mounting

location

to

provide

better

circuit

isolation.

N

o

o

ex:

o
o

:"'l

1•

Chassis

With

a

Sin~le

3

Section

Capacitor

-

Disconnect

all

wires

(usually

five)

connecting

to

poslhve

termma

softhree

sechon

electrolytic

capacitor

for

Cl25,

C126,

and

C127.

Trace

allofthese

wires

through

the

instrument

cabling

and

disconnect

other

endofwire.

Remove

wires

completely

or

clip

them

offatpoint

of

entry

into

cabling.

Chassis

With3Separate

Capacitors

-

Potentiometer

Rl23

(control

"R")

will

have

two

wues

connected

to

ltS

center

termlnaI.

Oneofthese

wires

goes

through

the

cabling

to

screen

grid

pin6of

VI02

and

VI03

as

well

as

transformer

TIOl.

This

wire

must

re-

main

in

the

instrument

as

is.

Trace

the

other

wire

connecting

the

center

terminal

of

Rl23

to

one

endofR154.

Disconnect

both

endsofthis

second

wire

and

remove

completely

or

clip

off

ends

at

point

of

entry

into

cabling.

Locate

the

common

junction

of

power

resistors

Rl48,

Rl49

(both

10,000

ohms),

and

two

wires.

The

other

endofoneofthese

wires

connects

toatie

lug

junction

ofR144,R145,

and

Cl27

near

the

VI05

tube

socket.

The

second

wire

terminates

at

the

cathode

of

series

voltage

regulator

tube

VI09.

26.

CIRCUIT

MODIFICATIONS

(Cont'd.)

BOTTOM

DECK

MODIFICATION

PROCEDURE

-

(Cont'd.)

MODIFICATION

TO

REDUCE

CARRIER

LEAKAGE-(Cont'd.)

1.

(Cont'd.)

..

".

If

this

second

wire

enters

step4can

be

eliminated.

ment,

disconnect

and

clip

cabling

across

rear

of

instrument,

it

need

not

be

changed

and

However,

if

this

wire

enters

cabling

across

front

of

instru-

off

both

ends

of

wire

at

point

of

entry

into

cabling.

2.

Add

or

move

capacitors

CI25,

C126,

and

Cll7

so

that

they

are

connected

electrically

as

shown

in

Fig.

4

and

as

described

below.

The

required

tubular

electrolytic

capacitor

(10

~,

450

volts)

is

available

under

-hp-

Stock

No.

18-10.

These

three

capacitor

s

have

their

negative

terminals

connected

toaconvenient

chas

sis

ground

and

their

positive

terminals

connected

as

follows:

C

125-to

tie

point

junction

ofR121,

T 10 1

transformer,

and

screen

grid

pins6for

Vl02

and

Vl03.

C

126-to

tie

point

junction

ofR136and

R 13 7inVI04plate

cir

cuit.

C127-to

tie

point

junction

of

R144

and

R145

in

Vl05

plate

circuit.

Refer

to

Fig.

11

for

approximate

mounting

positions.

It

will

be

necessary

to

add

all

three

of

these

capacitors

to

any

instrument

from

which

a

single

triple

section

electrolytic

capacitor

is

removed

as

directed

in

step

1.

3.

Remove

R154

(15,000

ohms,

±lO%,2watts,

-hp-

Stock

No.

25-l2K)

from

present

mounting

terminals

and

reconnect

as

directed

in

the

procedure

that

follows.

L

ocate

the

junction

ofR144

andR145

which

is

usually

a

terminal

on

one

endofa

dual

tie

lug

strip.

The

opposite

endofthis

tie

lug

strip

may

be

vacant

or

have

other

compo-

nents

and

wires

connected

to

it.

Any

such

connection

to

this

second

terminal

must

be

moved

to

an

electrically

equivalent

point

elsewhere

in

the

instrument.

If

this

is

not

convenient,

mountanew

tie

lug

close

enough

to

provide

a

mounting

terminal

for

one

end

ofR154

when

the

other

endisconnected

to

the

tie

lug

junction

ofR144

andR145.

Mount

R154

between

the

two

tie

lugs

just

identified.

This

connects

one

resistor

end

to

the

junction

of

R144

and

R145

and

the

other

endtoa

vacant

insulated

tie

lug.

Connect

a

wire

between

this

vacant

tie

lug

and

circuit

point

to

which

screen

grids

(pin6)of

Vl02

and

Vl03

are

connected.

4.

Connect

a

wire

between

power

supply

series

regulator

tube

(Vl09)

cathode

and

junction

of

R144,

R145,

and

R154.

This

wire

need

not

be

added

if,

in

step

I,itwas

not

neces-

sary

to

remove

a

wire

connecting

these

two

points

together.

If

in

doubt,

add

this

sec-

ond

wire

as

no

harm

can

be

done

by

doing

so.

POWER

SUPPLY

MODIFICATION

-

The

power

supply

for

all

instruments

is

fundamentally

the

same.

However,

there

have

been

minor

circuit

changes

and

different

tube

types

used

for

power

supply

circuitry

as

shown

by

Figs.

4,

6,

7C,

and

7D.

As

long

asapower

supply

is

functioning

properly

as

determined

by

tests

given

in

the

FINAL

TEST

procedure

section,

there

is

no

need

to

attempt

any

type

of

power

supply

modernization.

Replace

power

supply

tubes

with

the

same

types

found

inaninstrument.

If

the

power

supply

inaparticular

instrument

becomes

erratic

or

fails

repeatedly,

dismantle

the

power

supply

and

rewire

according

to

Fig.

4

schematic

diagram.

Install

new

parts

throughout,

change

tube

sockets

as

required,

andifnecessary

change

the

power

transformer.

The

power

transformer

change

will

beamust

when

modernizing

extremely

old

instruments

havingatype

2A3

tube

for

the

series

regulator

tube.

After

rebuilding

a

power

supply,

complete

steps1and2.of

PRELIMINAR

Y

TESTS

&

ADUST-

MENTS

and

check

harmonic

distortion

as

described

in

step

10ofFINAL

TEST

procedure.

Measure

local

oscillator

frequency

with

main

tuning

dial

at

"0"

and

FINE

TUNING

control

vertical.

The

local

oscillator

should

tune

to20KC

with

control

"F"

in

the

approximate

cen-

ter

of

its

tuning

range.

VJ

a

o

~

o

o

N

'-'
'-'

-

VJ

o

-

(]l
(]l

•

It''l

~

o

C"'\

-

.....

.....

N

o

o

<

o

o

C"'\

27.

CIRCUIT

MODIFICATIONS

(Cont'd.)

BOTTOM

DECK

MODIFICATION

PROCEDURE

-

(Cont'd.)

OTHER

LOWER

DECK

MODIFICATIONS

-

The

following

changes

should

be

incorporated

in

instruments

only

when

required

or

applic-

able.

Replacement

of

any

frequency

determining

components

such

as

Cl12,

Cl13,

R138,

or

R139

in

steps2and3will

necessitate

a

complete

frequency

calibration

according

to

step

14

and

15ofFINAL

TEST

procedure

in

this

manual.

1.

This

modification

applies

to

instruments

with

Serial

No.

947

and

below.

Instruments

with

higher

serial

numbers

had

this

component

change

made

during

manufacture.

Replace

the3watt,

115

volt

lamp

(R140)inVI05

cathode

circuit

with

a 10

watt,

230

volt

lamp

available

under

-hp-

Stock

No.

211-29.

Complete

step2of

PRELIMINARY

TESTS

&

ADJUSTMENTS.

Resistor

R143

will

beafixed

resistor

in

instruments

requiring

this

change.

The

series

padding

resistor

value

will

be

from0to

1000

ohms.

If

this

adjust-

ment

range

is

not

adequate

foraparticular

lamp

bulb,

reject

the

bulb

and

tryadifferent

one.

2.

Local

oscillator

frequency

determining

capacitors

Cl12

and

Cll3

should

be

silver

mica

or

ceramic

type

units

with

low

or

zero

temperature

coefficients.

Silver

mica

capacitor

-hp-

Stock

No.

15-27

is

recommended

for

replacement

ofC112

and

Stock

No.

15-90

for

replacement

of

Cl13.

3.

Os

cillator

frequency

stability

can

be

improved

in

some

older

instruments

by

replacing

frequency

determining

resistors

R138

and

Rl39.

If,

inaparticular

instrument,

these

special

precision

resistors

(7000

ohms,

wire

wound)

are

found

to

haveastamped

mark-

ingof"7K",

they

should

be

replaced

with

new

type

-hp-

Stock

No.

3A-26A

which

have

the

same

resistance

but

no

stamped

markings.

These

are

wound

withanew

type

wire

having

an

improved

temperature

coefficient.

GENERAL

-

29.

TROUBLE

SHOOTING

CAUSE

AND/OR

REMEDY

TROUBLE

SYMTOM

The

notes

giveninthe

TROUBLE

CHART

that

follow

are

based

on

-hp-

experience.

The

more

common

troubles,

their

symptoms,

and

remedy

are

given.

Itisbeyond

the

scope

of

this

manual

to

include

all

possible

or

obscure

and

rare

troubles.

If

an

instrument

develops

trouble

symptoms

not

covered

by

this

chart,

repair

analysis

will

be

simplified

if

the

CIRCUIT

DESCRIPTION

giveninthis

manual

is

usedtoobtainacomplete

understanding

of

the

instrument

circuitry.

All

circuit

references

refer

to

Figs.3and4unless

otherwise

noted.

Signal,

ac,

or

dc

voltages

when

mentioned

here,

are

measured

between

the

indicated

points

and

the

chassis

unless

specified

otherwise.
Any

tubes

with

standard

RETMA

characteristics

may

be

used

for

tube

replacements

as

explained

in

the

TUBE

COMPLEMENT

&:

TUBE

REPLACEMENTS

section.

Inagreat

number

of

cases,

in-

strument

trouble

can

be

traced

toadefective

tube.

Modulator

tubes

VI02

and

VI03

must

be

se-

lected

for

balance

and

freedom

from

hum,

noise,

and

distortion.

Oscillator

tubes

VI05

and

VI06

or

meter

tubes

V9

and

VIO

occasionally

must

be

selected

for

minimum

effect

with

line

voltage

changes.

TROUBLE

CHAR

T -

Measurement

of

power

supply

dc

current

will,

in

many

cases,

aidinlocalizing

the

cause

of

in-

strument

failure.

The

total

B+

current,

measured

at

the

power

transformer

center

tap,

will

nor-

mally

be

approximately

75

mao

The

upper

deck

B+

current,

measured

on

either

sideofRl57,

will

normally

be

approximately

ZO

mao

Measure

the

combined

plate

and

screen

current

for

the

series

regulator

tube

VI09to

determine

the

regulated

B+

current

delivered

to

the

lower

deck.

This

lower

deck

current

will

normally

be

approximately

55

mao

These

current

figures

are

shown

on

the

schematic

diagram

of

Fig.4at

the

points

of

measurement.

Fuse

FIOI

burned

out.

Rectifier

tube

VIIO

defective.

Nodcvoltage

from

power

Filter

capacitor

s C 119

CIZO

or

CIZI

and

CIZZ

shorted

supply.

Short

circuit

in

power

supply

distribution

system.

Choke

LIOZorLI03

open.

Power

transformer

T I03defective.

Nodcinputtoregulated

supply.

Tubes

VI07,

VIOa.

or

VI09

defective.

NoB+from

regulated

portion

Power

transformer

T 103defective.

of

power

supply.

Capacitor

CIZ7

defective.

Short

circuit

in

regulated

power

supply

dlstribution

system.

Regulated

B+

outputishigh

and

Anyone

or

all

tubes

VI07.

VIOa,

and

VI09

defective.

cannot

be

settoZ40

volts

with

R 15Z

control.

Supply

also

Anyone

of

several

resistors

in

voltage

regulator

cir-

will

not

regulate.

cuit

have

increased

in

value

or

opened

up.

Regulated

B+

outputisnormal

Tube(s)

VI07,

VIOa,

and/or

VI09

defective.

(Z40

volts)

but

power

supply

Defective

rectifier

tube

VIlO.

will

not

regulate

withachange

Power

transformer

TI03

defective.

in

line

voltage.

Electrolytic

capacitors

C

119.

CIZO,

CIZ

1.

CIZZ,

or

CIZ7

defective.

Regulated

B+

outputislow

and

Tube(s)

VI07,

VIOa,

and/or

VI09

defective.

cannot

be

settoZ40

volts

with

Rectiller

tube

VIIO

defective.

Rl5Z

control.

Supply

also

Power

transformer

TI03

defective.

will

not

regulate.

Electrolytic

capacitors

C119.

cno.

CIZI,

CIZZ,

or

Cl27

defective

Capacitor

CIZ4

(0.05

uf)

defective.

Shorted

B+

wirinl:(inlower

deck.

Shorted

tube

anywhere

ln

lower

deck.

Tubeinlower

deck

drawing

excessive

plate

current

due

toadefective

coupling

capacitor.

N

o

o

<

o

o

~

l.t'l

lll'

-

o

~

-

-

-

30.

TROUBLE

SHOOTING

(Cont'd.)

TROUBLE

CHART-(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

Tube

VIOS

(617)

or

VI06

(6F6)

defective.

Cathode

lamp(R140)

unscrewed

or

open.

Grid

cap

for

VIOS

disconnected.

Shorted

plates

in

tuning

capacitor

CIII.

Oscillator

dead

when

measured

Trimmer

capacitors

C114,C115,

or

Cl23

shorted.

at

junction

of

R138,

R142,

Capacitors

C

112,

C

113,

C

116,C117,

C1I8,

orC127

andC117.

shorted.

Resistors

R138

or

Rl39

defective.

Capacitors

C116,

orC117

open.

Resistors

R144,

R14S,

R148,

orR149

open.

Failure

of

plate

or

heater

supplies

for

tubes

VIOS

and

VI06.

Nooscillator

voltage

at

cathodes

See

preceding

trouble

symptom.

of

modulator

VI02

and

VI03.

Capacitor

C

lIB

open.

Tube

VI02

or

VI03

shorted.

Excessive

oscillator

voltage

Control

Rl43

or

resistor

Rl42

open.

with

controlR143

not

effective.

Socket

forR140

lamp

shorted.

Lamp

Rl40

resistance

may

be

too

low.

Replace

with

10

watt,

230

volt

lamp.

Os

cillator

output

is

distorted.

Tube

VIOS

(617)

or

VI06

(6F6)

defective.

Resistor

R141

defective.

Incorrect

dc

voltages

on

these

tubes

duetodefective

resistors,

leaky

feedback

capacitor

C

117orcoupling

capacitor

C

116.

Oscillator

operating

at

wrong

Fixed

capacitors

CIl2

or

CIl3

defective.

frequency

for

some

reason

Variable

capacitor

C

114

orC123

disconnected.

other

than

mal-adjustment

Frequency

determining

resistors

Rl3B

or

R139

defec-

of

frequency

determining

tive.

A

drop

of

solder

can

very

easily

short

out

a

components.

section

of

these

wire

wound

resistors.

Defective

tube

anywhere

in

upper

deck.

Defective

meter

movement.

MILLIVOLTS

meter

dead.

Defective

coupling

or

by-pass

capacitors

in

upper

deck.

No

heater

or

B+

voltage

in

upper

deck

duetodefectlve

cable

or

connecting

plug,

Shorted

or

open

signal

cable

from

lower

deck.

Defective

tube

for

anyone

or

all

stages

VIOl

through

VI06.

Transformer

TIOI

defective.

Local

os

cillator

not

functioning.

Defective

coupling

or

by-passcapacitor.

Power

supply

failure.

Control

potentiometer

R 1OBdefective.

Switch

Sl02

defective.

METER

MULTIPLIER

and/or

METER

SENSITIVITY

attenuator

defective,

Defective

tube

in

selective

amplifier.

Low

B+

from

power

supply.

Low

gain

in

selective

Defective

coupling,

feedback,

and/or

by-pass

capacitor

amplifier.

in

amplifier.

Open

10

fJi

decoupling

capacitor

for

CB,

CIS,

C20,

and

lor

C31

which

will

cause

degenerative

feedback.

Tuned

circuits

outofalignment.

Low

gain

in

selective

Tuned

circuits

outofalignment.

amplifier

onlyinthe

sharp

Potentiometers

RB,

R27,

R43,

and

RSBinfeedback

(30)

position.

circuits

are

outofadjustment.

.....

.....

-

w

o

-

U1
U1

Potentiometer

s

RB,

R27, R43,

and

R5B

in

feedback

circuits

are

outofadjustment.

Grounded

terminal

on

potentiometer

RB,

R27,

R43,

or

R5B.

Amplifier

gain

too

high

in

Grounded

terminal

on

anyone

section

of

either

of

the

sharp

tuning

(30)

position

two4gang

potentiometers

for

NEGATIVE

FEED-

only.

BACK

and

HALF

BAND

WIDTH

controls.

In

some

older

instruments,

the

top

deck

bottom

plate

did

not

have

an

insulating

strip

and

occasionally

the

control

terminals

short

out

on

the

bottom

plate.

One

or

more

of

the

shielded

cablesto

either

of

the

4

gang

potentiometer

s

may

be

shorted

inte

rnall

y.

This

is

more

likely

to

happen

in

older

cables

having

rubber

insulation.

Poorly

grounded

toroid

coil

shield

cans.

Scrape

paint

or

trim

off

insulating

paper

as

required

to

obtain

a

good

contact

between

can

and

lid.

Improperly

tuned

and

adjusted

amplifier

stage

as

ex-

Top

deck

oscillating.

Oscilla-

plained

in

Alignment

ofSele

ctiveAmplifier

under

tion

usually

more

pronounced

Test

Procedure.

with

HALF

BAND

WIDTH

con-

Potentiometer

RB,

R27,

R43,

and/or

R5B

in

feedback

trol

in

the

sharp

position.

circuit,

outofadjustment.

Component

in

any

feedback

circuit,

open

or

shorted

to

ground.

Capacitors

C37,

C3B,

C39,

and/or

C40

(10

~1Ji),

de-

fective

or

missing.

Shorted

terminal

or

open

section

in4gang

potentiom-

eters

for

NEGATIVE

FEEDBACK

and

HALF

BAND

WIDTH

controls.

One

or

more

of

the

shielded

cables

to

either

of

the

4

gang

potentiometer

s

may

be

shorted

internally.

This

is

more

likely

to

happen

in

older

cables

having

rubber

insulation.

Modulator

tubes

VI02

and

Vl03

must

be

selected

so

thatabalance

canbeobtained

with

controls

"C"

and

"R"

in

the

approximate

center

of

their

tuning

range.

Potentiometer

R

117

should

also

beinthe

approximate

center

of

its

range

for

this

check

and

will

then

have

to

be

readjusted

according

to

instruc-

tions

in

FINAL

TEST

step

10.

Modulator

will

not

balance

according

to

CALIBRATION

If

capacitor

"C"

(CI07)

or

resistor

"R"

(R123)

bal-

PROCEDURE

instructions.

ance

away

off

center,

temporarily

transpose

tubes

VI02

and

VI03

and

note

position

of

controls

when

balanced.

If

control

position

has

shifted

to

the

other

side

of

center,

tubes

VI02

and

VI03

are

at

fault.

If

there

is

no

change

in

control

position,

check

com-

ponents

in

modulator

circuit

other

than

tubesV102

and

VI03.

Modulation

transformer

TIOl

defective.

Open

or

off

value

resistor

forR122orR

124

which

are

normally

10,

000

ohms.

capacItor

C 1U(for

control

"C"

shorted

duetodamaged

plates

or

foreign

conductive

material

between

plates.

Potentlometer

R

123

for

control

"R

",

open.

Potentiometer

R

117

open

or shorted.

Open

or

off

value

resistorfor

Rll6

or

RllB

which

are

normally

B2,

000

ohms.

I.t'l

~

o

~

-

-

-

N

o
o

<

o
o

~

TROUBLE

SHOOTING

(Cont

'd.)

TROUBLE

CHART-(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

31.

32.

T R

OUBLESHOOTING

(Cont

'd.)

TROUBLE

CHAR

T -

(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

No60cps

calibrating

signal

with

Resistor

R

106

open.

"S"

lever

switch

(Sl02)

flip-

Defective

"S"

lever

switch

(Sl021.

pedtothe

right

andaVOLTS

Contacts

dirty

in

"S"

lever

switch.

meter

reading

of5volts.

Short

circuit

across

resistor

R

107.

The

60

cps

calibrating

signal

Resistor

RI07

open.

measures

5

volts

instead

of

Short

circuit

across

resistor

RI06.

0.5

volt

on

MILLIVOLTS

meter.

Hum

balance

potentiometer

R

159orground

strap

to

to

this

potentiometer

may

be

open.

By-pass

capacitor

C

109onVI04

cathode

may

be

grounded

to

ground

side

of

peaking

coil

LIO1ortothe

chassis

at

the

tube

socket.

Connect

to

point

providing

mini-

Excessive

carrier

leakage

as

mum

carrier

leakage.

explained

in

FINAL

TEST

Single

ground

wire

from

METER

SENSITIVITY

attenu-

step

7.

ator

maybe

grounded

atV104

tube

socket

or

ground

side

of

LIOl.

Connect

to

point

giving

minimum

carrier

leakage.

Instruments

with

Serial

No.

1369

and

below

should

be

modernized

to

reduce

carrier

leakage

as

given

in

the

CIRCUIT

MODERNIZATIONS

section

of

this

manual.

If

V9

and

VIOinthe

MILLIVOLTS

meter

circuit

are

weak,

the

meter

reading

will

drop

off

when

the

line

voltage

drops.

Select

tubes

for

replacement

that

produce

minimum

change

in

the

meter

reading.

Poor

line

voltage

response

Tubes

for

VIOl,

Vl02,

Vl03,

and/or

Vl04

may

be

weak.

as

explained

in

FINAL

Changes

in

line

voltage

have

little

effect

on

the

selec-

TEST

step

3.

tive

amplifier

stages.

If

tubes

for

VIaS

andV106inthe

oscillator

are

weak,

excessive

oscillator

frequency

change

andaloss

in

injection

voltage

will

result

when

the

line

voltage

is

reduced.

Select

tubes

for

replacement

that

pro-

duce

minimum

change

in

the

MILLIVOLTS

meter

reading.

Loss

of

power

supply

regulation

will

have

the

same

ef-

fect

as

weak

tubes

for

the

oscillator.

Instruments

with

Serial

o.

1329

and

below

should

be

modernized

according

to

the

TOP

DECK

MODERN-

Excessive

drift

of

the

tuned

IZI

G

PROCEDURE

given

in

the

CIRCUIT

MODIFI-

circuits

as

indicated

by

the

CATIONS

section

of

this

manual.

necessity

of

making

re-

Defective

toroid

coil

for

Ll

L2

L3

and/or

L4.

peated

adjustments

of

the

Selective

amplifier

improperly

aligned.

NEGATIVE

FEEDBACK

Replacement

toroid

coil

not

aged

long

enough.

See

control.

HEAT

RUN

CHECK

given

under

TEST

PROCEDURE.

Toroid

coils

will

occasionally

deteriorate

with

age,

particularly

in

older

instruments,

and

become

un-

stable.

It

may

be

necessary

to

replace

anyone

or

all

four

coils.

Excessive

hum

as

determined

Defective

tube

for

anyone

of

VIOI

through

Vl06

in

the

by

FINAL

TEST

step8in

lower

deck

or

any

6SJ7

tube

in

the

selective

ampli-

TEST

PROCEDURE

section

fier.

of

this

manual.

Stray

coupling

between

CI02

(0.5

pi)

in

VIOl

cathode

circuit

and

heater

leads.

Separate

lead

sand

capa-

citor

as

far

as

possible.

Pin1of

some

tube

sockets

are

grounded

to

the

chassis.

Check

these

grounds

forapossible

loose

connection.

Check

all

cable

and

attenuator

ground

connections.

In

some

older

instruments,

the

lower

deck

bottom

plate

was

fas

tened

to

the

ins

ideofthe

cabinet.

Connect

a

flexible

wire

between

this

plate

and

the

bottom

chassis.

•

v.>

~

o

>

o
o

N

......

......

-

v.>

o

-

U1
U1

Excessive

hum

as

determined

Defective

power

supply

filter

capacitors.

by

FINAL

TEST

step8in

Check

ground

connections

of

electrolytic

capacitors.

TEST

PROCEDURE

section

Hum

balance

potentiometer

(RI59)

is

not

properly

of

this

manual.

(Cont'd.

)

adjusted.

The

METER

MULTIPLIER

ground

lead

should

be

con-

nected

to

the

ground

sideofthe

input

gain

control

RIOS.

A

second

insulated

wire

from

RIOS

ground

terminal

should

then

run

down

through

the

chas

sis

hole

and

connect

toaground

lug

on

VI02

socket.

Remove

any

panel

ground

connection

at

the

ground

sideofRIOS.

Resonance

curve

has

60

cps

Defective

tubeinVIOl,

VI02,

VI03,

VI04,

VI05,

and/

"hump"

as

determined

by

or

VI06

positions.

A

defective

type

6SJ7

tube

for

FINAL

TEST

step

9A

in

first

two

or

three

tubes

in

the

selective

amplifier

TEST

PROCEDURE

section.

can

also

produce

the

60

cps

"hump".

The

braided

shielding

on

the

cables

connecting

to

the

two

four

gang

potentiometer

sisnot

insulated

in

some

older

instruments.

Ground

loops

resulting

from

this

exposed

shieldin-g

may

causeanonsym-

Resonance

curve

not

sym-

metrical

response

curve.

Replace

complete

as-

metrical.

sembly

consisting

of

controls

with

insulated

cables.

Peaking

coil

LIOI

may

be

open.

Defectivefour

gang

potentiometer

for

NEGATIVE

FEEDBACK

control.

Top

deck

oscillating.

See"

Top

deckoscillating".

in

this

chart.

Anyone

or

all

tubes

VIOl

through

VI06

may

be

de-

fective.

Pin1of

VIOl

tube

socket

may

notbegrounded.

Excessive

harmonic

distortion.

Modulator

tubes

VI02

and

VI03

may

be

mismatched.

See

step

10ofFINAL

TEST

Modulation

transformer

T 101

may

be

unbalanced,

re-

in

TEST

PROCEDURE

sec-

place.

tion.

Potentlometer

R

117

may

be

incorrectly

adjusted.

Re-

fertostep

10ofFINAL

TEST

in

the

TEST

PRO-

CEDURE

section.

Peaking

coil

LIOI

may

be

open.

Leaky

coupling

capacitor

or

open

by-pass

capacitor

in

lower

deck.

Variable

selectivity

will

not

Replace

the

four

gang

potentiometer

which

functions

as

pass

test

giveninstep

11

the

HALF

BAND

WIDTH

control.

Thecontrol

only,

of

FINAL

TEST

in

TEST

oranassembly

which

includes

both

four

gang

po-

PROCEDURE

section.

tentiometers

and

all

shielded

connecting

cables

can

be

obtained

from

the

factory.

Check

and

adjust

mechanical

zero

on

meter.

Excessive

MILLIVOLTS

High

residual

emission

of

type

bHb

tube

used

for

V18.

meter

tracking

error.

Replace

this

tube.

Heater

to

cathode

leakage

in

6SN7GT

tube

used

for

V9.

Replace

tube.

Capacitor

C35

(0.05

JJi)

leaky.

Low

instrument

sensitivity

Low

injection

voltage

from

local

oscillator.

See

as

determined

in

step

13

FINAL

TEST

step

2.

of

FINAL

TEST

in

TEST

Weakor

defective

tubes

for

anyone

or

all

tubes

VIOl

PROCEDURE

section.

through

V104.

Adjust

regulated

B+

voltage.

See

FINAL

TEST

step

1.

De1ectlve

T 10 1

modulation

transformer.

Capacitors

CI03,

C lOS,

and

lor

CliO

may

be

defective.

•

TROUBLE

SHOOTING

(Cont'd.)

TROUBLE

CHART-(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

33.

34.

TROUBLE

SHOOTING

(Cont'd.

)

..

TROUBLE

CHART-(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

Low

instrument

sensitivity

Check

all

tubes

for

abnormal

plate,

screen,

grid,

as

determined

in

step

13

cathode,

and

heater

voltages.

of

FINAL

TEST

in

TEST

Defective

attem:.ator

for

METER

MULTIPLIER

or

PROCEDURE

section.

METER

SENSITIVITY

control.

(Cont'd.

)

Tubes

V9

and/or

VlO

defective

or

weak.

Defective

MILLIVOLTS

meter

movement.

Peaking

coil

LlO1may

be

open.

Low

gain

in

selective

amplIfier.

This

is

covered

else-

where

in

this

TROUBLE

CHART.

Main

frequency

dial

off

calibra-

Variable

"F"

control

capacitor

C

114

may

be

disconnected.

tion

as

determined

in

step

Variable

capacitor

C123

may

be

disconnected.

14ofFINAL

TEST

in

TEST

Defective

fixed

capacitors

CIl2

and/or

Cll3.

PROCEDURE

section

of

this

Tubes

VIOS

and/or

VlOt>

defective.

manual.

Wire

wound

frequency

determining

resistor

R138

or

R

139

off

value

duetoshorted

turns.

Look

for

a

drop

of

solder

on

resistor.

Oscillator

output

not

flat

over

the

range

of

the

instru-

ment.

See

step

l4BofFINAL

TEST

in

TEST

PRO-

Poor

frequency

response.

CEDURE

section.

Coupling

capacitors

C101,

C

103.

and/orClOS

defective.

Check

for

defective

component

in

cir

cuits

ahead

of

input

to

modulator

tubes

Vl02

and

VI03.

Operator

failed

to

turn

input

gain

control

(SET

TO

100)

full

clockwise

to

MAX,

ortoset

the

HALF

BAND

WIDTH

control

to

same

position

used

for

calibration.

Operator

failed

to

adjust

to

the

same

refer

ence

level

Voltage

calibration

error.

See

with

the

NEGATIVE

FEEDBACK

control

when

chang-

step

16ofFINAL

TEST

in

in!:!

selectivity.

TEST

PROCEDURE

section.

Defective

VOLTS

meter

movement.

Wirewound

resistors

for

Rl06

and

Rl07

have

changed

value,

opened

up,

or

are

shorted.

Pad

to

proper

ratio

by

connecting

resistor

in

parallel

with

Rl06

orR107.

A

drop

of

solder

can

short

outasection

in

oneofthese

resistors.

Adjust

VOLTS

meter

to

zero

with

instrument

turned

off

or

control

"V"

full

counterclockwise.

Check

for

noise

in

main

and

regulated

power

supplies.

Check

power

supply

electrolytic

capacitors.

tubes

and

resistors.

Check

local

oscillator

forasteady

output

as

directed

Unsteady

MILLIVOLTS

in

step4of

PRELIMINAR

Y

TESTS

&

ADJUSTMENTS

meter

indication.

in

the

TEST

PROCEDURE

section

of

this

manual.

Check

electrolytic

decouplin!:!

capacitors

in

top

deck.

Check

coupling,

feedback,

and

by-passcapacitor

s

ln

both

chassis.

Check

foranoisy

tube

anywhere

in

instrument.

Refer

to

step

12ofTOP

DECK

MODERNIZATION

PRO-

CEDURE

in

the

CIRCUIT

MODIFICATIONS

section

of

this

manual.

A

20

KC

external

signal

source

operating

near

the

300A

may

radiate

a

signal

directly

into

the

selective

ampli-

fier

of

the

300A

and

causeabeat

effect.

Mechanical

zero

set

on

MILLIVOLTS

meter

is

out

of

Residual

MILLIVOLTS

adjustment.

meter

reading.

Residual

emission

or

hum

in

VlO

type

6H6

tube.

Re-

place

with

selected

tube.

Hum

in

V9

tvoe

6SN7

tube.

Top

deck

oscillating.

See

"Top

deck

oscillating"

in

this

same

section.

VJ

~

o

>

o
o

rv

......

......

-...

VJ

o

-...

\.Jl
\.Jl

TROUBLE

SHOOTING

(Cont'd.)

TROUBLE

CHART-(Cont'd.)

TROUBLE

SYMPTOM

CAUSE

AND/OR

REMEDY

35.

L{)
L{)

-

o

l""'l

-

.....

.....

N

o
o

<

o
o

l""'l

Residual

MILLIVOLTS

Type

6Y6

tube

for

Vl09

in

power

supply

is

oscillating.

meter

reading.

(Cont'd.)

Install

resistor

R

164inseries

with

the

screen

2rid.

Oscillating

reference

tube

for

Vl07

(OA2

or

neon

bulb)

in

power

supply.

Replace.

Excessive

hum.

See

corrective

steps

given

under

this

heading

elsewhere

in

this

chart.

Leaking

O.

05~coupling

capacitor

for

C35inthe

meter

circuit.

A20KC

external

signal

source

operating

near

the

300A

may

radiate

a

signal

directly

into

the

selective

ampli-

fier

of

the

300A.

Hum

balance

potentiometer,

Heater

lead

or

tube

socket

heater

pin

shorted

to

the

R

159,

smoking

or

bur

ned

chassis.

out.

Microphonics

Microphonic

tube

anywhere

in

instrument.

Modulator,

oscillator

and

output

amplifier

tubes

in

lower

deck

as

well

as

first2or3tubes

in

selective

amplifier

should

be

checked

first.

Cathode

lamp(R140)inoscillator

may

be

microphonic

or

loose

in

socket.

Loose

center

contact

in

lamp

socket

for

R140.

Replace

socket.

Poor

ground

connection

at

negative

terminal

ofanelec-

trolytic

capacitor.

Modulation

transformer

T

101

defective.

Poor

ground

connection

or

solder

joint

anywhere

in

instrument.

Intermittant

short

circuit.

Loose

connection

to

MILLIVOLTS

meter

or

defective

meter

movement.

Defective

resistor

anywhere

in

instrument.

300A002

11/10/55

•

..

I MILLIVOLTSI

VTVII

V9.

VIO

~

UNREGULATED

POWER

SUPPLY

VIIO

4

STAGE

20

KC

SELECTIVE

I F

AMPLIFIER

VI,

V2.

V3,

V4

V5,V6.

V7,V8

i

QINEGATIVE FEEDBACK I

" 0 IHALF BANDWIDTH I

\ \

240

VOLT

REGULATED

POWER

SUPPLY

VIOl

VI08

VI09

AMPLI

FIER

VI04

VOLT

METER

RANGE

SI!

TCH

All

REMAINING CIRCUITS

OF

WAVE

ANALYZER

VOLT

METER

GAl

N

CONTROL

BALANCED

MODULATOR

VI02,

Vl03

i

LOCAL

0

SCI

LLATOR

VI05

VI06

10

TO

1

VOLTAGE

DIVIDER

INPUT

GAIN

I.--o.-r-I

PHASE

INVERTER

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I - ! I V tOt

VOLTMETER

q

IMETER

MULTIPLIER I

q

~

(CAPACITY

BALANCE

qIMETER SENSITIVITY I

ADJUSTMENT)

\

\

\

\

Q

SET

TO

tOO

FOR

\

o

~

(RESISTANCE BALANCE

\

VOLTAGE

MEASUREMENT

ADJUSTMENT)

\

\

\

\

\

\

\

\

\

q~

\

\

\

\

\

\

\

\

\

\

\

\

\ \

6.3

VAC

~

VOLTAGE

CONTROL

I • ,

FROM

POWER

SUPPLY

I

I

O~

I

/

/

I

00

(METER

(SET

TO

5 VOLTS)

CALIBRATE)

/ /

I I

/ /

/ I

/ 0IFINE TUNING I

OIO-

16KC

I

(COARSE TUNING)

115/230

VAC

50/60

CYCLE

LINE

Fig.

1.

Model

300A

Block

Diagram

loU

--J

.

38.

10

20

50

60

70+-0---11"--..,...-_--..,...

......

_-

......

..,...-__.--..,...-"""""---

t400'\, t300'\,

+200'\,

tlOO'\,

20Ke

-IOO'\,

-200'\,

-300'\,

-400'1.

FREQUENCY

Selectivity

Char

acteristics

of

Model

300A

Amplifier

h I-h- '--c--

"

"i

,

In

1

10

I

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10

20

30

50

CYCLES

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100

200

300

500

Half

Band

Width

Characteristics

of

Model

300A

Amplifier

Fig.

2.

Characteristics

of

Selective

Amplifier

System

•

•

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900

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o I

PANEL

CONTROl I

~

ISCREWDRIVER CONTROLI

NOTES:

!THESE

NOJI:S

ALSO

APPLY

TO

THE SCHEMATIC

OF

MOOEl

300A

MODJLATOR, OSCIlLATOR, 8 POWER SUPPLY SECTIONS.)

CONDITIONS

rs

DC

VOLTAGE

MEASUREMENT:

l.

115f2301I,

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POWER

SUPPLY

2.

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r!jJ

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SERIAL 1330 8 ABOVE

FIG.3

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SCHEMATIC DIAGRAM OF

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1000

5000

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NOTE'

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2

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INPUT

r!jJ

MODEL

300A

MODULATOR,

OSCILLATOR

8

POWER

SUPPLY

(BOTTOM

DECK)

SERIAL

1610 a ABOVE

FIG.4

THIS

C'''CUIT

1$

BASICALLY CORRECT, BUT

SMALL

DIFFERENCES

M1I.Y

EXIST

FOR

ANY

PMHICULAR

INSTRUMENT COMPARISION

AND

CROSS-CHECKING

WILL

ENABLE

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NOTES:

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MODEL

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a

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1I!lIZ3OV, 60'\.0 POWER SUPPLY

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FIG. 6

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3000

Fig.7A.

Early

Amplifier

&

Meter

Circuits

Fig.

7B.

Late

Amplifier

&

Meter

Cir

cuits

REGULATED

B+

OUTPUT

R51

e2K

R50
22K

T5

6L6G

R54

270K

L2

6H

.-

__

.,.-_-,-~

TR

3

~:

~ffjJJ

III

~:

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~

o 10FF-ONI

52

F

125A

IFUSE I

Fig.

7C.

One

of

Earliest

Power

Supplies.

Series

Regulator

Tube

T5

May

BeaType

2A3.

IS'l

Ll"\

-

0

VI09

,V)

6L6GA

-

-

REGULATED

-

e+

OUTPUT

RI55
560K

N

0

RI56

0

10K

~

RI53

0

33K

0

M

RI52
25K

RI51
47K

::

~Rl:±il'lr

~:

VI09

-1'

~

o

IOFF-oNI

5104

F

101

1.25A

IFUSEJ

Fig.

7D.

Later

Power

Supply

Circuit.

Same

Basic

Circuit

as

Fig.

7C

WithaChange

in

Tube

Complement

&

Control

Rl57

Added.

44.

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Fig.

8.

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for

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Selectivity

Curves

45.

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30

40

DECIBELS

50

60

70

Fig.

9.

Graph

for

Converting

Attenuation

In

Decibels

to

Voltage

Ratio

..

CI22

MI

CI04

AS

*'"

0"-

.

Fig.

10.

Top

View

of

Typical

Bottom

Deck

and

Back

of

Control

Panel.

Top

Deck

Removed.

•

•

300A002

11/30/55

•

•

'._-

,

Fig.

II.

Bottom

View

of

Typical

Bottom

Deck

~

-.I

.

,.j:>.

00

.

v

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v

L2

010

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r:J

LI

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12.

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View

of

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Top

Deck

With

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Removed

to

Show

Details

of

Torroid

Coil

Assembly.

Top

Deck

Separated

From

Control

Panel.

"

•

Fig.

13.

Bottom

View

of

Typical

Top

Deck

With

Control

Panel

and

Bottom

Plate

Removed

•

*"

....0

.

LIST

OF

CODE LETTERS

USED

IN

TABLE

OF

REPLACEABLE PARTS

TO

DESIGNATE THE MANUFACTURERS

CODE

CODE

LETTER

MANUFACTURER

ADDRESS

LETTER

MAN

UFACTU

RER

ADDRESS

A

Aerovox

Corp.

New

Bedford,

Moss.

AK

Hommerlund

Mfg.

Co.,

Inc.

New

YorkI,N.

Y.

B

Allen-Bradley

Co.

Milwaukee4,Wis.

AL

Industrial

Condenser

Corp.

Chicago

18,

III.

C

Amperite

Co.

New

York, N.

Y.

AM

Insuline

Corp.ofAmerica

Manchester,N.H.

D Arrow,

Hart&Hegeman

Hartford,

Conn.

AN

Jennings

Radio

Mfg.

Corp.

San

Jose,

Calif.

E

Bussman

Manufacturing

Co.

St. Louis,

Mo.

AO

E.F.Johnson

Co.

Waseca,

Minn.

F

Carborundum

Co.

Niagara

Falls, N.

Y.

AP

Lenz

Electric

Mfg.

Co.

Chicago

47,

III.

G

Centralab

MilwaukeeI,Wis.

AQ

Micro-Switch

Freeport,

III..

H

Cinch-Jones

Mfg.

Co.

Chicago

24,

III.

AR

Mechanical

Industries

Prod.

Co.

Akron8,Ohio

HP

Hewlett-Packard

Co.

Palo

Alto,

Calif.

AS

Model

Eng. &

Mfg.,

Inc.

Huntington,

Ind.

I

Clarostat

Mfg.

Co.

Dover,N.H.

AT

The

Muter

Co.

Chicago5,III.

J

Cornell

Dubilier

Elec.

Co.

South

Plainfield, N.

J.

AU

Ohmite

Mfg.

Ca.

Skokie,

III.

K

Hi-Q

DivisionofAerovox

Olean,N.Y.

AV

Resistance

Products

Ce.

Harrisburg,

Po.

L Erie

Resistor

Corp.

Erie b, Po.

AW

Radio

Condenser

Co.

Camden

3, N.

J.

M

Fed.

Telephone&Radio

Corp.

Clifton,N.J.

AX

Shallcross

Manufacturing

Co.

Collingdale,

Po.

N

General

Electric

Co.

Schenectady

5, N.

Y.

AY

Solar

Manufacturing

Co.

Los

Angeles

58,

Calif.

0

General

Electric

Supply

Corp.

San

Francisco,

Calif.

AZ

Sealectro

Corp.

New

Rochelle,N.Y.

P

Girard-Hopkins

Oakland,

Calif.

BA

Spencer

Thermostat

Attleboro,

Mass.

Q

Industrial

Products

Co.

Danbury,

Conn.

BC

Stevens

Manufacturing

Co.

Mansfield,

Ohio

R

I

nternational

Resistance

Co.

Philadelphia

8, Po.

BD

Torrington

Manufacturing

Co.

Van Nuys,

Calif.

S

Lectrohm

Inc.

Chicago

20,

III.

BE

Vector

Electronic

Co.

Los

Angeles

b5,

Calif.

T

Littlefuse

Inc. Des Plaines,

III.

BF

Weston

Electrical

Inst.

Corp.

Newark

5, N.

J.

U

Maguire

Industries

Inc.

Greenwich,

Conn.

BG

Advance

Electric&Relay

Co.

Burbank,

Calif.

V

Micamold

Radio

Corp.

Brooklyn 37,N.Y.

BH

E.I.DuPont

San

Francisco,

Calif.

W

Oak

Manufacturing

Co.

Chicago

10,

III.

BI

Electron

ics

Tube

Corp.

Philadelphia

18,

Po.

X

P.R.Mallory

Co.,

Inc.

Indianapolis,

Ind.

BJ

Aircraft

Radio

Corp.

Boonton,N.J.

Y

Radio

Corp.ofAmerica

Harrison,N.J.

BK

Allied

Control

Co.,

Inc.

New

York 21,N.Y.

Z

Sangamo

Electric

Co.

Marion,

III.

BL

Augat

Brothers, Inc.

Attleboro,

Mass.

AA

SarkesTarzian

Bloomington.

Ind.

BM

Carter

Radio

Division

Chicago,

III.

BB

Signal

Indicator

Co.

Brooklyn 37, N.

Y.

BN

CBS

Hytron

Radio&Electric

Do nvers,

Mass.

CC

Sprague

Electric

Co.

North

Adams,

Mass.

BO

Chicago

Telephone

Supply

Elkhart, Ind.

DD

Stackpole

Carbon

Co.

St.

Marys,

Pa.

BP

HenryL.Crowley

Co.,

Inc.

West

Orange,N.J.

EE

Sylvania

Electric

Products

Co.

Warren,

Po.

BQ

Curtiss-Wright

Corp.

Carlstadt,N.J.

FF

Western

Electric

Co.

New

York5,N.

Y.

BR

AllenB.DuMont

Labs

Clifton,N.J.

GG

Wilkor

Products,

Inc.

Cleveland,

Ohio

BS

Excel Transformer

Co.

Oakland,

Calif.

HH

Amphenol

Chicago

50,

III.

BT

General

Radio

Co.

Cambridge

39,

Mass.

II

Dial

Light

Co.ofAmerica

Brooklyn 37, N.

Y.

BU

Hughes

Aircraft

Co.

Culver

City,

Calif.

JJ

Leecraft

Manufacturing

Co.

New

York, N.

Y.

BV

International

Rectifier

Corp.

EI

Segundo,

Calif.

KK

Switch

craft,

Inc.

Chicago

22,

III.

BW

James

Knights

Co.

Sandwich,

III.

LL

Gremar

Manufacturing

Co.

Wakefield,

Mass.

BX

Mueller

Electric

Co.

Cleveland,

Ohio

MM

Carad

Corp.

Redwood

City,

Calif.

BY

Precision

Thermometer

& Inst.

Co.

Philadelphia

30, Po.

NN

Electra

Manufacturing

Co.

Kansas

City,

Mo.

BZ

Radio

Essentials Inc.

Mt.

Vernon, N.

Y.

00

Acro

Manufacturing

Co.

Columbus

Ib,

Ohio

CA

Raytheon

Manufacturing

Co.

Newton,

Mass.

PP

Alliance

Manufacturing

Co.

Alliance,

Ohio

CB

Tung-Sol

Lamp

Works, Inc.

Newark

4, N.

J.

QQ

Arco

Electronics, Inc.

New

York 13, N.

Y.

CD

Varian

Associates

Palo

Alto,

Calif.

RR

Astron

Corp.

East

Newark,

N. J.

CE

Victory

Engineering

Corp.

Union, N.

J.

SS

Axel

Brothers

Inc.

Long

Island

City,N.Y.

CF

Weckesser

Co.

Chicago

30,

III.

TT

Belden

Manufacturing

Co.

Chicago

44,

III.

CG

Wilco

Corporation

Indianapolis,

Ind.

UU

Bird

Electronics

Corp.

Cleveland

14,

Ohio

CH

Winchester

Electronics,

Inc.

Santa

Monica,

Calif.

VV

Barber

Colman

Co.

Rockford,

III.

CI

Maleo

Tool & Die

Los

Angeles

42,

Calif.

WW

Bud

Radio

Inc.

Cleveland3,Ohio

C.J

Oxford

Electric

Corp.

Chicago

15,

III.

XX

AllenD.Cardwell

Mfg.

Co.

Pla'r.ville,

Conn.

CK

Co

mloc-Fastener

Corp.

Paramus,N.J.

YY

Cinema

Engineering

Co.

Burbank,

Calif.

CL

GeorgeK.Garrett

Philadelph'a

34, Po.

ZZ

Any

brand

tube

meeting

CM

Union Switch &

Signal

Swissvale, Po.

RETMA

standards.

CN

RodioReceptor

New

York

II,N.Y.

AB

Corning

Glass

Works

Corning,N.Y.

CO

Automatic

& Precision

Mfg.

Co.

Yonkers, N.

Y.

AC

Dale

Products,

Inc.

Columbus,

Neb.

CP

Bassick

Co.

Bridgeport2,Conn.

AD

The

Drake

Mfg.

Co.

Chicago

22,

III.

CQ

Birnbach

Radio

Co.

New

York

13,N.Y.

AE

Eleo

Corp.

Philadelphia

24, Po.

CR

Fischer

Specialties

Cincinnatib,Ohio

AF

Hugh

H. Eby

Co.

Philadelphia

44, Po.

CS

Telefunken

(c/o

MVM,

Inc.l

New

York, N.

Y.

AG

Thomas

A. Edison, Inc.

West

Orange,N.J.

CT

Potter-Brumfield

Co.

Princeton,

Ind.

AH

Fansteel

Metallurgical

Corp.

North

Chicago,

III.

CU

Cannon

Electric

Co.

Los

Angeles,

Calif.

AI

General

Ceramics&Steatite

Corp.

Keasbey,N.J.

CV

Dynoc,

Inc.

Polo

Alto,

Calif.

AJ

The

Gudemon

Co.

Sunnyvale,

Calif.

CW

Good-All

Electric

Mfg.

Co.

Ogallala,

Nebr.

•

•

51.

TABLE

OF

REPLACEABLE

PARTS

GENERAL

-

The

following

parts

list

may

be

used

to

determine

replacement

parts

for

all

-hp-

Model

300A

Harmonic

Wave

Analyzers.

To

determine

the

required

replacement

part,

refer

to

the

schematic

diagrams

giveninFig.3and

Fig.

4.

Use

the

circuit

reference

obtained

from

the

schematic

dia-

grams

to

identify

correct

component

in

the

Table

of

Replaceable

Parts.

To

assure

receiving

the

correct

replacement

part,

be

sure

to

include

instrument

Model

and

Serial

numbers

as

well

as

the

-hp-

Stock

Number

and

Description

of

the

desired

part.

Failure

to

include

this

information

may

result

in

delay

duetoa

wrong

part

being

received

or

additional

correspond-

ence

being

required

before

proper

part

identification

is

possible.

The

Model

300A

has

been

manufactured

overaspan

of

several

years

with

no

major

change

in

spec-

ifications

orinbasic

circuitry.

The

components

used,

however,

have

changed.

Different

tube

type,

improved

toroid

coils,

and

other

miscellaneous

components

of

higher

quality

have

been

in-

corporated

whenever

they

became

available.

The

componeJ;lts

given

in

this

parts

list

are

those

used

in

the

latest

instruments.

Some

older

instruments

must

be

completely

modernized

before

these

new

parts

can

be

used.

Re-

fer

to

the

TUBE

COMPLEMENT

&

TUBE

REPLACEMENTS,

CIRCUIT

DESCRIPTION,

and

CIR-

CUIT

MODIFICATIONS

sections

of

this

manual.

Factory

modernization

is

recommended

for

older

instruments

not

covered

under

CIRCUIT

MODIFICATIONS.

Field

modernization

of

these

older

in-

struments

is

not

practical.

It

is

necessary

in

some

instances

to

substitute

parts

in

this

instrument.

These

substitutions

do

not

impair

instrument

performance.

Either

the

substitute

part

or

the

part

specified

in

the

Replace-

able

Parts

Table

may

be

used

for

replacement

purposes.

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

$ STOCK

REF.

DESCRIPTION,

MFR.

• &

MFR.

DESIGNATION NO.

*

TOP

DECK

Cl

Capacitor:

variable,

air

dielectric,

12-ll

5

100

J.LJ.Lf,

(partofToroid

Coil

Assembly)

All

Star

C2

Capacitor:

Value

selectedatfactory.

4

C3

Capacitor:

fixed,

paper

dielectric

16-15

14

.047

J.Lf,

±1O%,

600 vdcw, 125°C

CC*

C4

Capacitor:

fixed,

paper

dielectric,

16-21 7

.001

J.Lf,

±1O%,

600 vdcw, 125°C

CC*

C5

Capacitor:

fixed,

paper

dielectric,

16-1

9

0.1

J.Lf,

±1O%,

600 vdcw, 125°C

CC*

C6,

7

SameasC3

C8

Capacitor:

fixed,

electrolytic,

18-10

7

10

J.Lf,

±50%, 450 vdcw,

85°C

X*

C9

SameasCl

ClO

SameasC2

*

See"

ListofManufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

*

Total

quantity

usedinthe

instrument.

52.

TABLE

OF

REPLACEABLE

PARTS

cmcurr

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION NO. #

TOP

DECK

(CONTINUED)

Cll

Same

as

C3

C12

Same

as

C4

C13

Same

as

C5

C14

Same

as

C3

C15

Same

as

C8

C16

Same

as

C3

C17

Same

as

Cl

C18

Same

as

C2

C19

Same

as

C3

C20

Same

as

C8

C21

Same

as

C4

C22

Same

as

C5

C23,24

Same

as

C3

C25

Same

as

Cl

C26

Same

as

C2

C27

Same

as

C3

C28

Same

as

C4

C29

Same

as

C5

C30

Same

as

C3

C31

Same

as

C8

C32

Same

as

C3

C33

Same

as

C4

C34

Capacitor:

fixed,

paper

dielectric,

16-22 1

.0022

J.1f,

±1O%,

600

vdcw,

125°C

CC*

C35

Same

as

C3

C36

Capacitor:

fixed,

electrolytic,

18-5 1

500

J.1J.1f,

15

vdcw,

85°C

X*

*

See

"LIst

of

Manufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

#

Total

quantity

usedinthe

instrument.

•

•

..

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

*

TOP

DECK

(CONTINUED)

C37, 38,

Capacitor:

fixed,

mica,

14-10

4

39,40

10

J.1J.1f,

±1O%,

.500 vdcw

v*

Jl

Connector,

female:2contact

H*

125-14 1

Ll,

2, 3, 4

Coil,

part

of

Toroid

Coil

Assembly

(not

separately

replaceable)

Ml

Meter,

indicating:

1 rna

movement

112-4 1

PI

This

circuit

reference

not

assigned

P2

Connector,

male:

4

contact,

125-10

}

cable

type

H*

Rl

Resistor:

fixed,

deposited

carbon,

31-830K

8

830,000

ohms,

±l%, 1 W

NN*

R2

Resistor:

fixed,

deposited

carbon,

31-900

4

900

ohms,

±l%, I W

Electrical

value

adjustedatfactory.

NN*

R3

Resistor:

fixed,

deposited

carbon,

31-5000

4

5000

ohms,

±l%, I W

NN*

R4

This

circuit

reference

deletedinlater

instruments

R5

Resistor:

variable,

composition,

210-23 1

linear

taper,4sections,

10,000

ohms/

sect.

G*

R6

Resistor:

fixed,

composition,

24-1M 6

1

megohm,

±1O%,

1 W

B*

R7

Resistor:

fixed,

composition,

24-100K

11

100,000

ohms,

±1O%,

1 W

B*

R8

Resistor:

variable,

composition,

210-18 5

linear

taper,

50,000

ohms

1*

R9

Resistor:

fixed,

deposited

carbon,

31-2M 2

2

megohms,

±1%,

1 W

NN*

RIO

Resistor:

fixed,

deposited

carbon,

31-80K 2

80,000

ohms,

±1%,

1 W

NN*

RI1

Resistor:

fixed,

composition,

24-68K

4

68,000

ohms,

±10%,

1 W

B*

RI2

Resistor:

fixed,

composition,

23-470K

4

470,000

ohms,

±1O%,

1/2 W

B*

*

See"

LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

*

Total

quantity

usedinthe

instrument.

53.

54.

TABLE

OF

REPLACEABLE

PARTS

cmcurr

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

#

TOP

DECK

(CONTINUED)

Rl3

Resistor:

fixed,

composition,

24-560

4

560

ohms,

±1O%,

I W

B*

Rl4

Resistor:

fixed,

composition,

24-470K

6

470,000

ohms,

±1O%,

I W

B*

Rl5

Same

as

R7

Rl6

Resistor:

variable,

composition,

210-24 I

4

sections,

100,000

ohms/sect.

G*

Rl7

Same

as

Rl

Rl8

Resistor:

fixed,

deposited

carbon,

31-479K

4

479,000

ohms,

±l%, I W

Electrical

value

adjustedatfactory

NN*

Rl9

Resistor:

fixed,

composition,

24-5600

I

5600

ohms,

±1O%,

I W

R20

Same

as

R2

R21

Same

as

R3

R22

Same

as

R6

R23

Same

as

R7

R24

Same

as

Rl2

R25

This

circuit

reference

deleted

in

later

instruments

R26

Resistor:

fixed,

deposited

carbon,

31-1. 63M 2

1.63megohms,

±l%, I W

NN*

R27

Same

as

R8

R28

Resistor:

fixed,

deposited

carbon,

31-56K

2

56,000

ohms,

±l%, 1 W

NN*

R29

Same

as

Rll

R30

SameasR13

R31

Same

as

R14

R32

Saine

as

R7

R33

Same

as

RI

R34

Same

as

Rl8

*

See

"List

of

Manufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

#

T,tal

Quantity

usedinthe

instrument.

..

..

•

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

#

TOP

DECK

(CONTINUED)

R35

Resistor:

fixed,

composition,

24-4700

2

4700

ohms,

±1O%,

1 W

B*

R36

Same

as

R2

R37

Same

as

R3

R38

Same

as

R6

R39

Same

as

R7

R40

Same

as

Rl2

R4l

This

circuit

reference

deletedinlater

instruments

R42

Same

as

R26

R43

Same

as

R8

R44

Same

as

R28

R45

Same

as

Rll

R46

Same

as

Rl3

R47

SameasRl4

R48

Same

as

R7

R49

Same

as

R35

R50

Same

as

Rl

R5l

This

circuit

reference

deletedinlater

instruments

R52

SameasR2

R53

Same

as

R3

R54

Same

as

R6

R55

Same

as

R7

R56

Same

as

Rl2

R57

Same

as

R9

R58

Same

as

R8

R59

Same

as

RlO

*See

"LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

#

Total

quantity

usedinthe

instrument.

55.

56.

TABLE

OF

REPLACEABLE

PARTS

cmcurr

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

#

TOP

DECK

(CONTINUED)

R60

Same

as

Rll

R61

Same

as

R13

R62

Same

as

R14

R63

Same

as

R7

R64

Same

as

R6

R65

Resistor:

fixed,

wirewound,

26-3000

2

3000

ohms,

±5%, 1 W

R*

R66

Resistor:

fixed,

composition,

24-1000 3

1000

ohms,

±1O%,

1 W

B*

R67

Same

as

R6

R68

Resistor:

fixed,

composition,

24-270K

3

270,000

ohms,

±1O%,

1 W

B*

R69

Resistor:

fixed,

composition,

24-33K

1

33,000

ohms,

±1O%,

1 W

B*

R70,

71

Resistor:

fixed,

composition,

24-22K

4

22,000

ohms,

±1O%,

1 W

B*

R72

Resistor:

fixed,

wire

wound,

26-18 1

7

ohms,

±1O%,

2 W

1*

R73

Resistor:

fixed,

composition

24-220

1

220

ohms,

±1O%,

1 W

B*

R74

Same

as

R18

R75,76

Resistor:

fixed,

composition,

23-150K

2

150,000

ohms,

±1O%,

1/2

W

Electrical

value

adjusted

at

factory

B*

R77

Same

as

Rl8

R78,

79,

Same

as

Rl

Electrical

value

80,81

adjusTedatfactory

VI

thru

Tube,

electron:

68J7

zz*

212

-6SJ7

12

V8

*

See"

LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table".

#

Total

quantity

usedinthe

instrument.

..

•

57.

TABLE

OF

REPLACEABLE

PARTS

CmCUIT

~

STOCK

REF.

DESCRIPTION,

MFR.

*

&

MFR.

DESIGNATION

NO.

41

TOP

DECK

(CONTINUED)

V9

Tube,

electron:

6SN7GT

or

6F8G

212-6SN7G'l

1

(replace

with

same

type

as

found

or

in

instrument.

See

TUBE

COM-

212-6F8G

PLEMENT

&

TUBE

REPLACE-

MENTS

section.)

ZZ*

VlO

Tube,

electron:

6H6

ZZ*

212-6H6 1

MISCELLANEOUS

Toroid

Coil

Assembly:

includes

3A-62

1

toroid

coil,

fixed

capacitor,

resistor,

and

trimmer

capacitor

HP*

BOTTOM

DECK

ClOl

Same

as

C5

C102

Capa.citor:

ii.xed,

paper

dielectric,

16-37

2

.

4'7

11f,

±1O%,

200 vdcw

CC*

C103

Same

as

C5

ClO'l

Capacitor:

fixed,

electrolytic,

18-3lHP

1

3

sections,

10

/If/sect.,

450

vdcw

CC*

CI05

Same

as

C5

CI06

This

circuit

reference

has

been

replaced

by

C125, C126, C127

CI07

Capacitor:

variable,

air

dielectric,

12-13 1

100

/l/lf

XX*

C108

Capacitor:

fixed,

mica,

14-47

1

1800

/l/lf,

±1O%,

500 vdcw

Z*

ClOg

Same

as

C102

ClIO

Same

as

C4

cm

Capacitor:

variable,

air

dielectric,

12-2

1

2

sections,

530

/l/lflsect.

AW*

C1l2

Capacitor:

fixed,

silver

mica,

15-27

1

510

/l/lf,

±5%, 500

vdcw

Electrical

value

adjusted

at

factory

A*

*

See

"List

of

Manufacturers

Code

Letters

For

Replaceable

Parts

Table"

•

#

Total

quantity

used

in

the

instrument.

58.

TABLE

OF

REPLACEABLE

PARTS

*

See"

LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table".

#

Total

quantity

usedinthe

instrument.

.

CIRCUIT

~

STOCK

IJ

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO. #

BOTTOM

DECK

(CONTINUED)

C1l3

Capacitor:

fixed,

silver

mica,

15-90

1

.470

fJ.fJ.f, ±5%, 500

vdcw

Electrical

value

adjusted

at

factory

V*

C1l4

Capacitor:

variable,

air

dielectric,

12-34

1

6 - 65

fJ.fJ.f

All

Star

C1l5

Capacitor:

variable}

air

dielectric,

12-33

1

3 -

11

fJ.fJ.f

All

Star

C1l6

Same

as

C4

C1l7,

118

Same

as

C5 .

C1l9, 120

Capacitor:

fixed,

paper

dielectric,

17-10

2

4

fJ.f,

600

vdcw

Z*

•

C12l,

122

Capacitor:

fixed,

electrolytic,

l8-20HP

2

20

fJ.f,

450 vdcw

CC*

C123

Capacitor:

variable,

air

dielectric,

12-11

100

Wf

All

Star

10

C124

Same

as

C3

C125, 126,

Same

as

C8

127

FlOl

Fuse:

1.

25

amp,

"Slo-Blo"

T*

211-58

1

1101

Lamp,

incandescent:

6-8V,

211-47 1

.15amp.,

#47

N*

.

LlOl

Coil,

R.F.:

30

mh

MM*

48-4

1

.

Ll02,

103

Filter,

reactor:

6H@125

rna,

911-4

2

240

ohms

Paeco

MlOl

Meter:

O-lOV,

"AC

calibrate".

This

112-8

1

meter

is

used

for

replacement

in

all

instruments

regardless

of

full

scale

calibration

of

original

meter.

Simpson

PlOl

Connector,

male:

2

contact,

125-22 1

cable

type

H*

P102

Connector,

female:

4

contact,

125-11 1

chassis

mounting

H*

~

•

•

•

•

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

~

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

4#

BOTTOM

DECK

(CONTINUED)

P103

Power

Cable

Elec.

Cords

812-56

1

RlOl, 102,

Re

sis

tor:

part

of

Mete r

Multiplie

r

103,104

Switch

Assembly

Rl05

Resistor:

variable,

wirewound,

210-2

2

linear

taper,

50

ohms,

±lO%

G*

R106,

107

Resistor:

fixed,

wirewound,

precision,

3A-26

2

900

and

100

ohms

Electrical

value

adjustedatfactory

HP*

Rl08

Resistor:

variable,

composition,

210-22

1

200,000

ohms,

±lO%

BO*

Rl09

Resistor:

fixed,

composition,

24-1. 8M

1

1.8megohms,

±1O%,

1 W

B*

RllO

Same

as

R7

Rlll

Same

as

R66

Rl12

Same

as

R70

Rl13

Resistor:

fixed,

composition,

24-15K

2

15,000

ohms,

±lO%,

1W

B*

Rl14

Same

as

R70

Rl15

Same

as

Rl4

Rl16

Resistor:

fixed,

composition,

24-82K

3

82,000

oluns,

±10%,

1 W

B*

Rl17

SameasR8

Rl18

SameasRl16

Rl19

SameasRl4

Rl20

Resistor:

fixed,

composition,

24-680

2

680

ohms,

±lO%,

1 W

B*

Rl21

Same

as

R70

Rl22

Resistor:

fixed,

composition,

24-10K 2

lO,

000

ohms,

±10%,

1W

B*

Rl23

Resistor:

variable,

composition,

210-15 2

linear

taper,

5000

ohms

G*

•

See

"List

of

Manufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

4#

Total

quantity

usedinthe

instrument.

59.

60.

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

If/J

STOCK

REF.

DESCRIPTION,

MFR.

* &

MFR.

DESIGNATION

NO.

#-

BOTTOM

DECK

(CONTINUED)

Rl24

Same

as

Rl22

Rl25

Same

as

R123

Rl26

thru

Resistor:

part

of

Meter

Sensitivity

Rl34

Switch

Assembly

Rl35

Same

as

R66

Rl36

Resistor:

fixed,

composition,

24-56K

4

56, 000

ohms,

±1O%,

1 W

B*

Rl37

Same

as

Rl22

Rl38,

139

Resistor:

fixed,

wirewound,

3A-62A

2

precision,

7000

ohms

HP*

Rl40

Lamp:

10W(see1under

OTHER

211-29

1

LOWER

DECK

MODIFICATIONS in

the

CIRCUIT MODIFICATIONS

section)

N*

Rl41

Same

as

Rl36

Rl42

Same

as

R65

Rl43

Resistor:

variable,

wirewound,

210-5 1

linear

taper,

1000

ohms

G*

Rl44

Same

as

R116

Rl45

Same

as

Rl36

Rl46

Same

as

R68

Rl47

Resistor:

fixed,

composition,

24-820

1

820

ohms,

±1O%,

1 W

B*

Rl48

Resistor:

fixed,

wirewound,

26-10 2

10,

000

ohms,

±1O%,10W S*

Rl49

Resistor:

fixed,

wire

wound,

27-4

1

10,

000

ohms,

±1O%,20W

S*

Rl50

~

Resistor:

fixed,

composition,

25-15K

1

15,

000

ohms,

±1O%,

2 W

B*

Rl51

<.

Same

as

Rl36

Rl52

Resistor:

variable,

composition,

210-11

1

linear

taper,

25, 000

ohms

G*

*

See"

LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table".

#

Total

quantity

usedinthe

instrument.

..

..

cmCUIT

REF.

TABLE

OF

REPLACEABLE

PARTS

I$j;

STOCK

DESCRIPTION,

MFR.*&MFR.

DESIGNATION NO. #

BOTTOM

DECK

(CONTINUED)

61.

Rl53

Resistor:

fixed,

composition,

27, 000

oluns,

±1O%,

1 W

B*

24-27K

1

Rl54

Same

as

Rl13

Rl55

Rl56

Resistor:

fixed,

composition,

560,000

ohms,

±1O%,

1 W

Resistor:

fixed,

composition,

1O,000oluns,

±1O%,

2 W

B*

B*

24-560K

1

25-10K 1

Rl57

Same

as

Rl48

Rl58

Rl59

Rl60,

161

Rl62
Rl63

Resistor:

fixed,

composition,

33

ohms,

±1O%,

1 W

SameasR105

Same

as

R7

Same

as

R68

Resistor:

fixed,

composition,

150

ohms,

±1O%,

2 W

B*

B*

24-33

25-150

1

1

Rl64

Same

as

Rl20

..

S101

S102

Input

Meter

Multiplier

Range

Switch

Assembly

Calibration

Switch

Assembly

SWitch,

calibration:

DPDT,

lever

type

HP*

Hp·

G*

3A-19I

3A-19C

310-156

1

1
1

S103
S104

T101
T102
T103

VlOl, 102,

103,104

Meter

Sensitivity

Switch

Assembly

HP*

Switch,

toggle:

SPST

D*

Transformer,

modulation

HP*

Transformer,

heater

BS*

Transformer,

power

(power

trans-

former

replacement

may

require

instrument

modernization.

See

CmCUIT

MODIFICATIONS

section)

BS·

Same

as

VI

3A-19M
310-11
3A-61
910-65
910-69

1
1

1

1

1

•

•

See"

ListofManufacturers

Code

Letters

For

Replaceable

Parts

Table"

.

#

Total

quantity uSedinthe

instrument.

G2.

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

<Fj;

STOCK

I~

REF.

DESCRIPTION,

MFR.

• &

MFR.

DESIGNATION

NO.

#

BOTTOM

DECK

(CONTINUED)

V105

Tube,

electron:

6J7

ZZ*

2l2-6J7

1

V106

Tube,

electron:

6F6

ZZ*

2l2-6F6

1

Vl07

Tube,

electron:

OA2

ZZ*

2l2-0A2

1

V108

Tube,

electron:

6SQ7

ZZ*

2l2-6SQ7

1

V109

Tube,

electron:

6L6GB

ZZ*

2l2-6L6G

IS

1

V110

Tube,

electron:

5U4GA/B

ZZ*

2l2-5U4GA/

1

B

4

MISCELLANEOUS

.

Binding

Post

Assembly:

black

HP*

AC-lOC

1

Binding

Post

Assembly:

red

HP*

AC-lOD

1

Coupler,

insulated

HP*

M-25

1

Capacitor:

assembly:

tuning,

3A-7

1

·~O

complete

HP*

Dial,

blank:

7"

diameter

HP*

3A-40

1

Drive,

planetary:

Natl.

Co.

149-11

1

Fuseholder

T*

140-16

1

Half bandwidth

control

HP*

3A-l5

B 1

•

Indicator,

dial

HP*

M-25

1

..

Indicator

Lamp

Assembly

11*

145-2

1

Insulator,

standoff:

1"x3/8"

AI*

34-1

I

Knob:

for

control

panel

door

HP*

G-74C

1

Knob:

engraved

R

HP*

G-74AG

1

Knob:

engraved

C

HP*

G-74AH

I

Knob:

engraved

F

HP*

G-74AJ

I

Knob:

engraved

G

HP*

G-74AK

I

Knob:

engraved

V

HP*

G-74AL

1

•

Knob:

engravedS(for

lever

switch)

HP*

G-74AM 1

*

See"

LIstofManufacturers

Code

Letters

For

Replaceable

Parts

Table".

#

Total

quantity

usedinthe

instrument.

"

•

TABLE

OF

REPLACEABLE

PARTS

CIRCUIT

cFjJ

STOCK

REF.

DESCRIPTION, MFR. * &MFR. DESIGNATION

NO.

#

MISCELLANEOUS (CONTINUED)

Knob:

METER

MULTIPLIER,

G-74N

2

METER

SENSITIVITY

HP*

Knob:

VOLTAGE

MEASUREMENT,

G-74S

2

FINE

TUNING

HP*

Knob:

tuning,

basic

diameter,

G-74Z

1

2

-3

ft±"

HP*

Knob:

NEGA TIVE

FEEDBACK,

G-74K

2

HALF BAND WIDTH

HP*

LampholC:er:

(for

R40)

A.D*

145-15

1

Label

Set:

"Calibrating

Procedure"

712-271

1

&

"Op~rating

Preca

tions"

HP*

Negative

feedback

control

assembly

HP*

3A-15A 1

Washer,

spring

HP*

3A-50

1

*

See"

ListofManufacturers Code

Letters

For

Replaceable

Parts

Table" .

# Total auantitv

used

in the instrument.

63.

SALES

AND

SERVICE OFFICES

IN

THE

U.S.

AND

CANADA

HEWLETT

~

PACKARD

•

..

•

ALABAMA

Huntsville,

35801

Hewlell-Packard

Southern

Sales

Division

Holiday

Office

Ctr.,

Suite

18

(205)

881-4591

TWX:

510-579-2204

ARIZONA

Scottsdale,

85251
Hewlell-Packard
Neely

Sales

Division

3009

No.

Scollsdale

Rd.

(6021

945-7601

TWX:

602-949-0111

Tucson,

85716
Hewlell-Packard
Neely

Sales

Division

232

So.

Tucson

Blvd.

(602)

623-2564

TWX:

602-792-2759

CALIFORNIA

Los

Angeles

Area
Hewlell-Packard
Neely

Sales

Division

3939

Lankershim

Blvd.

North

Hollywood

91604

(213)

877-1282

and

766-3811

TWX:

910-499-2170

Sacramento,

95821

Hewlett·Packard

Neely

Sales

Division

2591

Carlsbad

Ave.

(916)

482-1463

TWX:

916-444-8683

San

Diego,

92106
Hewlell·Packard
Neely

Sales

Division

1055

Shafter

Street

(714)

223-8103

TWX-714·276-4263

San

Francisco

Area
Hewlell-Packard
Neely

Sales

Division

501

Laurel

Street

San

Carlos

94071

(415)

591-7661

TWX:

910·376-4390

COLORADO

Englewood,

80110
Hewlell·Packard
Lahana

Sales

Division

7965

East

Prentice

(303)

771-3455

TWX,

303-771-3056

CONNECTICUT

Middletown,

06458
Hewlett-Packard
Yewell

Sales

Division

589

Saybrook

Rd.

(203)

346-6611

TWX:

203-346·7433

FLORIDA

Miami,

33125
Hewlett·Packard
Florida

Sales

Division

2907

Northwest

7th

SI.

(305)

635-6461

Orlando,

32803
Hewlell·Packard
Florida

Sales

Division

621

Commonwealth

Ave.

(305)

425-5541

TWX:

305-275·1234

St.

Petersburg,

33708

Hewlett-Packard

Florida

Sales

Division

41O·150th

Ave_,

Madeira

Beach

(813)

391-0211

TWX,

813-391-0666

GEORGIA

Atlanta,

30305
Hewlell·Packard
Southern

Sales

Division

3110

Maple

Drive,

N.

E.

(404)

233-1141

TWX:

810-751·3283

ILLINOIS

Chicago,

60645
Hewlell-Packard
Crossley

Sales

Division

2501

West

Peterson

-Ave.

(312)

275-1600

TWX:

910-221-0277

INDIANA

Indianapolis,

46205
Hewlell-Packard
Crossley

Sales

Division

3919

Meadows

Dr.

(317)

546·4891

TWX:

317·635·4300

KENTUCKY

Louisville,

40218
Hewlett·Packard
Southern

Sales

Division

Suite4,3411

Bardstown

Rd.

(5021

459-414D

TWX:

810-535-3128

MARYLAND

Baltimore,

21207
Hewlell·Packard
Horman

Sales

Division

6660

Security

Blvd.

(301l

944·5400

Washington,D.C.

Area
Hewlett-Packard
Horman

Sales

Division

941

Rollins

Avenue

Rockville

20852

(301l

427-7560

TWX:

710-828-9684

MASSACHUSETTS

Boston

Area
Hewlell·Packard
Yewell

Sales

Division

Middlesex

Turnpike

Burlington

01804

(617)

272-9000

TWX,

710-332·0382

MICHIGAN

Detroit,

48235

Hewlell-Packard

Crossley

Sales

Division

14425

West

Eight

Mile

Road

(313)

342-5700

TWX:

313-342-0702

MINNESOTA

St.

Paul,

55114
Hewlett·Packard
Crossley

Sales

Division

842

Raymond

Avenue

(612)

646-7881

TWX:

612·551·0055

MISSOURI

Kansas

City,

64131

Harris·Hanson

Company

7916

Paseo

Street

(816)

444-9494

TWX:

816-556·2423

SI.

Louis,

63144

Harris·Hanson

Company

2814

South

Brentwood

Blvd.

(314)

647-4350

TWX,

314-962·3933

NEW JERSEY

Asbury

Park

Area
Hewlell·Packard
Robinson

Sales

Division
Shrewsbury
(201l

747-1060

Englewood,

07631
Hewlell-Packard
RMC

Sales

Division

391

Grand

Avenue

(201l

567-3933

NEW MEXICO

Albuquerque,

87108
Hewlell·Packard
Neely

Sales

Division

6501

Lomas

Blvd.,N.E.

(505)

255-5586

TWX:

505·243-8314

Las

Cruces,

88001
Hewlett·Packard
Neely

Sales

Division
114S.Water

Street

(505)

526-2486

TWX,

505·524-2671

NEW YORK

New

York,

10021
Hewlell-Packard
RMC

Sales

Division

236

East

75th

Street

(212)

879-2023

TWX,

710-581·4376

Rochester,

14625
Hewlell-Packard
Syracuse

Sales

Division

800

Linden

Avenue

(716)

381-4120

TWX,

716·221-1514

Poughkeepsie,

12601
Hewlett·Packard
Syracuse

Sales

Division

82

Washington

SI.

(914)

454-7330

TWX,

914-452-7425

Syracuse,

13211
Hewlett·Packard
Syracuse

Sales

Division

Pickard

Bldg.,E.Molloy

Rd.

(315)

454-2486

TWX:

315-477-1375

NORTH CAROLINA

High

Point,

27262
Hewlell-Packard
Southern

Sales

Division

1923N.Main

Street

(919)

882-6873

TWX,

510·926-1516

OHIO

Cleveland,

44129
Hewlell-Packard
Crossley

Sales

Division

5579

Pearl

Road

(216)

884·9209

TWX,

216·888-0715

Dayton,

45409

Hewlell·Packard

Crossley

Sales

Division

1250W.Dorothy

Lane

(513)

299·3594

TWX,

513·944-0090

PENNSYLVANIA

Camp

Hill

Hewlell-Packard

Robinson

Sales

Division

(717)

737-6791

Philadelphia

Area
Hewlell-Packard
Robinson

Sales

Division

144

Elizabeth

Street

West

Conshohocken

19428

(2151

248-1600

and

828-6200

TWX,

215-828-3847

Pillsburgh

Area
Hewlell-Packard
Crossley

Sales

Division

2545

Moss

Side

Blvd.

Monroeville

15146

(412)

271-5227

TWX:710-797

-3650

TEXAS

Oallas,

75209
Hewlell-Packard
Southwest

Sales

Division

P.O.

Box

7166,

3605

Inwood

Rd.

(214)

357-1881

and

332-6667

TWX:

910-861-4081

Houston,

77027
Hewlell-Packard
Southwest

Sales

Division

P.O.

Box

22813,

4242

Richmond

Ave

.
(713)667·2407
TWX,

713·571-1353

UTAH

Salt

Lake

City,

84115
Hewlett-Packard
Lahana

Sales

Division

1482

Major

SI.

(801l

486·8166

TWX:

801-521-2604

VIRGINIA

Richmond,

23230
Hewlett-Packard
Southern

Sales

Division

2112

Spencer

Road

(703)

282-5451

TWX:

703-282-9986

WASHINGTON

Seattle

Area
Hewlell-Packard
Neely

Sales

Division

11656

N.E.8th

SI.

Bellevue

98004

(206)

GL4-3971

TWX,

910-443-2303

CANADA

Montreal,

Quebec

Hewlett-Packard

(Canada)

Ltd.

8270

Mayrand

Street

(514)

735·2273

TWX:

610-421-3484

Ottawa,

Ontario

Hewlett-Packard

(Canada)

Ltd.

1762

Carling

Avenue

(613)

722-4223

TWX,

610·562-1952

Toronto,

Ontario

Hewlett-Packard

(Canada)

Ltd.

1415

Lawrence

Avenue,

West

(416)

249-9196

TWX,

610-492-2382

1-65

INTERNATIONAL SALES AND SERVICE OFFICES

..

ARGENTINA

MauricioA.Saurez

Telecommunicaciones

Carlos

Calvo

224,

Buenos

Aires

Tel:

30-6312

AUSTRALIA

Sample

ElectroniCs

(Vic,)

Pty

ltd.

9·11

Cremorne

Street

RichmondE.1.

Victoria

Tel:

42·4757(3lines)

Sample

Electronics

(N.S.W')

Pty.

ltd.

4

Grose

Street,

Glebe,

Sydney

New

South

Wales

Tel:

69-6338(6lines)

AUSTRIA

Unilabor

G.m.b.H.

Rummelhardtgasse

6/3
Vienna
Tel:

426.181

BELGIUM

Hewlett·Packard

Benelux

SA

20-24

RuedeI'Hopital,

Brussels

Tel:

11.22.20

BRAZIL

Ciental

ImportacaoEComercio

ltda.

Rua

Cons.

Crispiniano,

69,

8.0And.,

Conj.

81,

Sao

Paulo

Tel:

32-4332

CANADA

Hewlett·Packard

(Canada)

ltd.

8270

Mayrand

Street

Montreal,

Quebec

(514)

735-2273

Hewlett-Packard

(Canada)

ltd.

1762

Carling

Avenue

Ottawa,

Ontario

(613)

722-8162

Hewlett-Packard

(Canada)

ltd.

1415

Lawrence

Avenue

W.

Toronto,

Ontario

(416)

249-9196

CHILE

Hector

Calcagni

Casilla

13942

Santiago

Tel:

6.42.26

DENMARK

Tage

Olsen

A/S

Ronnegade

1

Copenhagen

~

Tel:

29.48.00

FINLAND

INTO

0 Y

P.O.Box

153

Meritullinkatu

11,

Helsinki

Tel:

66.39.09

and

35.125

FRANCE

Hewlett·Packard

France

150

Boulevard

Massena

Paris

13e

Tel:

707.97.19

GERMANY

Hewlett-Packard

V.m.b.H.

Steindamm

35,

Hamburg

Tel:

24.05.51

Hewlett·Packard

V.m.b.H.

Kurhessenstrasse

95

FrankfurtamMain

Tel:

52.00.36

Hewlett-Packard

V.m.b.H.

Reginfriedstrasse

13

Munich

9

Tel:

49.51.21

22

Hewlett-Packard

Vm.b.H.

Technisches

Buro

Herrenbergerstrasse

110

703

Biiblingen,

Wurttemberg

Tel:

6971

GREECE

K.

Karayannis

Klaftmonos

Square,

Athens

124

Tel:

230.301(5lines)

INDIA

The

Scientific

Instrument

Company,

Ld.

6,

Tej

Bahadur

Sapru

Road,

Allahabad

I

Tel:

2451

The

Scientific

Instrument

Company,

Ld.

240,

Dr.

Dadabhai

Naoroji

Road,

Bombay

I

Tel:

26·2642

The

Scientific

Instrument

Company,

Ld.

11,

Esplanade

East,

Calcutta

I

Tel:

23·4129

The

Scientific

Instrument

Company,

Ld.

30,

Mount

Road,

Madras

2

Tel:

86339

The

Scientific

Instrument

Company,

Ld.

B-7,

Ajmeri

Gate

Extn.,

New

Delhi

I

Tel:

271053

IRAN

Telecom

ltd.

P.O.Box

1812,

Tehran

Tel:

43850,

48111

ISRAEL

Electronics&Engineering

Ltd.

16

Kremenetski

St.,

Tel

Aviv

Tel:

35021(3lines)

ITALY

Hewlett-Packard

Italiana

S.p.A.

Viale

Lunigiana

46,

Milan

Tel:

69.15.84/5

6

Hewlett-Packard

Italiana

S.p.A.

Piazza

Marconi,

25
Roma-Eur
Tel:

59.25.44/5

JAPAN

Yokogawa-Hewlett-Packard

ltd.

2270

Ishikawa-cho

Hachioji,

Tokyo

Tel:

Hachioji

0426-3-1231

(19

lines)

Yokogawa-Hewlett-Packard

Ltd.

No.3,

6-chome,

Aoyama-Kitamachi

Akasaka,

Minato-ku,

Tokyo

Tel:

403-0073,

403-0074,

403-0075

Yokogawa·Hewlett-Packard

Ltd.

No.8,

Umeda,

Kita-ku,

Osaka

City

Tel:

361-3084,

341-2095

Yokogawa·Hewlett-Packard

ltd.

No.4,

3-chome,

Himeikedori,

Chigusa·ku,

Nagoya

City

Tel:

75·8545

KOREA

American

Trading

Company,

Korea,

ltd.

112·35

Sokong-Dong

SeoulP.O.

Box

1103

Seoul

Tel:

3-7049,

3-7613

NETHERLANDS

Hewlett-Packard

Benelux

N.V.

23

Burg

Roellstraat,

Amsterdam

W.

Tel:

(o20l

13.28.98

and

13.54.99

NEW ZEALAND

Sample

Electronics

(N.

Z,)

Ltd.

8

Matipo

Street

Onehunga

S.E.5,

Auckland

Tel:

565-361

NORWAY

Morgenstierne&Co.

AlS
Ingeniprfirma
6

Wessels

Gate,

Oslo

Tel:2016

35

PORTUGAL

Telectra
Rua

RodrigodaFonseca

103

P.O.Box

2531

Lisbon

1

Tel:

68 6072and686073and

686074

PUERTO RICO & VIRGIN ISLANDS

San

Juan

Electronics,

Inc.

150

PoncedeLeon,

Stop

3

P.O.Box

5167

Pta.deTierra

Sta.,

San

Juan

00906

Tel:

722-3342,

724-4406

SPAIN

ATAIO,

Ingenieros

A.

Aguilera,

NO.8,

Madrid

15

Tel:

223.27.42,

223.41.71,

and

224.84.97

SOUTH AFRICA

F.H.Flanter&Co.

(Pty,),

Ltd.

Rosella

House

Buitencingle

Street,

Cape

Town

Tel:

3-3817

SWEDEN

H-P

Instrument

AB

Centralvagen

28,

Solna

Centrum

Tel:

08·83.08.30

and

10-83.08.30

SWITZERLAND

Max

Pual

Frey

Wankdorffeldstrasse

66,

Bern

Tel:

(031)

42.00.78

TAIWAN (FORMOSA)

Hwa

Sheng

Electronic

Co.,

ltd.

21

Nanking

West

Road,

Taipei

Tel:

4·6076,

4·5936

TURKEY

TELEKOM

Engineering

Bureau

P.O.

Box

376-Galata,

Istanbul

Tel:

49.40.40

UNITED

KINGDOM

Hewlett-Packard

ltd.

Dallas

Road

Bedford,

England

Tel:

Bedford

68052

VENEZUELA

Citec,C.A.
Edit.

Arisan-Of

#4

Avda.

FranciscodeMiranda·Chacaito

Apartado

del

Este

10.837,

Caracas

Tel:

71.88.05

YUGOSLAVIA

Belram

SA

83

Av.

des

Mimosas

Brussels

15,

Belgium

Tel:

35.29.58

...

•

IN

EUROPE

Hewlett-Packard,S.A.
54

Route

des

Acacias

Geneva,

Switzerland

Telephone:

(022)

42.81.50

Telex:

2.24.86

Cable:

HEWPACKSA

1-65

For

Sales

and

Service AssistanceinAreas

IN

LATIN AMERICA

Hewlett-Packard

Inter-Americas

1501

Page

Mill

Road

Palo

Alto,

California

94304,

U.S.A.

Telephone:

(415)

326-7000

TWX:

910·373-1267

Telex:

033811

Cable:

HEWPACK

Not listed Contact:

ELSEWHERE

Hewlett-Packard
International

Marketing

Department

1501

Page

Mill

Road

Palo

Alto,

California

94304,

U.S.A.

Telephone:

(415)

326-7000

TWX·

910-373-1267

Telex:

033811

Cable:

HEWPACK

SALES AND SERVICE OFFICES

IN

THE

U.S. AND CANADA

HEWLETT

ili

PACKARD

•

•

ALABAMA

Huntsville,

35801

Hewlett-Packard

Southern

Sales

Division

Holiday

Office

Ctr..Suite

18

(205)

881-4591

TWX:

510-579-2204

ARIZONA

Scottsdale,

85251
Hewlett-Packard
Neely

Sales

Division

3009

No.

Scottsdale

Rd.

(602)

945-7601

TWX:

602-949-0111

Tucson,

85716
Hewlett-Packard
Neely

Sales

Division

232

So.

Tucson

Blvd.

(602)

623-2564

TWX:

602-792-2759

CALIFORNIA

Los

Angeles

Area
Hewlett-Packard
Neely

Sales

Division

3939

Lankershim

Blvd.

North

Hollywood

91604

(213)

877-1282

and

766·3811

TWX:

910·499·2170

Sacramento,

95821

Hewlett-Packard

Neely

Sales

Division

2591

Carlsbad

Ave.

(916)

482-1463

TWX:

916444·8683

San

Diego,

92106
Hewlett-Packard
Neely

Sales

Division

1055

Shafter

Street

(714)

223·8103

TWX·714-2764263

San

Francisco

Area
Hewlett-Packard
Neely

Sales

Division

501

Laurel

Street

San

Carlos

94071

(415)

591·7661

TWX:

910-376·4390

COLORAOO

Englewood,

80110
Hewlett-Packard
Lahana

Sales

Division

7965

East

Prentice

(303)

771-3455

TWX:

303-771·3056

CONNECTICUT

Middletown,

06458
Hewlett·Packard
Yewell

Sales

Division

589

Saybrook

Rd.

(203)

346-6611

TWX:

203·346·7433

FLORIDA

Miami,

33125
Hewlett-Packard
Florida

Sales

Division

2907

Northwest

7th

St.

(305)

635-6461

Orlando,

32803
Hewlett-Packard
Florida

Sales

Division

621

Commonwealth

Ave.

(305)

425·5541

TWX:

305·275-1234

SI.

Petersburg,

33708
Hewlett-Packard
Florida

Sales

Division

41O·150th

Ave.,

Madeira

Beach

(813)

391·0211

TWX:

813-391·0666

GEORGIA

Atlanta,

30305

Hewlett-Packard

Southern

Sales

Division

3110

Maple

Drive,

N.

E.

(404)

233·1141

TWX:

81D-751·3283

ILLINOIS

Chicago,

60645
Hewlett·Packard
Crossley

Sales

Division

2501

West

Peterson

-Ave.

(312)

275·1600

TWX:

910·221·0277

INDIANA

Indianapolis,

46205

Hewlett-Packard

Crossley

Sales

Division

3919

Meadows

Dr.

(317)

5464891

TWX:

317·635·4300

KENTUCKY

Louisville,

40218
Hewlett·Packard
Southern

Sales

Division

Suite4.3411

Bardstown

Rd.

(502)

459-4140

TWX:

810-535-3128

MARYLAND

Baltimore,

21207
Hewlett-Packard
Horman

Sales

Division

6660

Security

Blvd.

(301)

944-5400

Washington,D.C.

Area
Hewlett-Packard
Horman

Sales

Division

941

Rollins

Avenue

Rockville

20852

(301)

427-7560

TWX:710-828-9684

MASSACHUSETTS

Boston

Area

Hewlett-Packard

Yewell

Sales

Division

Middlesex

Turnpike

Burlington

01804

(6J7)

272-9000

TWX,

710-332-0382

MICHIGAN

Detroit,

48235
Hewlett-Packard
Crossley

Sales

Division

14425

West

Eight

Mile

Road

(313)

342-5700

TWX:

313-342-0702

MINNESOTA

SI.

Paul,

55114
Hewlett-Packard
Crossley

Sales

Division

842

Raymond

Avenue

(612)

646-7881

TWX:

612-551-0055

MISSOURI

Kansas

City,

64131

Harris-Hanson

Company

7916

Paseo

Street

(816)

444-9494

TWX:

816·556-2423

SI.

Louis,

63144

Harris-Hanson

Company

£814

South

Brentwood

Blvd.

(314)

647-4350

TWX:

314-962-3933

NEW JERSEY

Asbury

Park

Area
Hewlett-Packard
Robinson

Sales

Division
Shrewsbury
(20U

747-1060

Englewood,

07631
Hewlett-Packard
RMC

Sales

Division

391

Grand

Avenue

(201)

567-3933

NEW MEXICO

Albuquerque,

87108
Hewlett-Packard
Neely

Sales

Division

6501

Lomas

Blvd.,

N.

E.

(505)

255-5586

TWX:

505-243-8314

Las

Cruces,

88001
Hewlett·Packard
Neely

Sales

Division
114S_Water

Street

(505)

526-2486

TWX:

505-524-2671

NEW YORK

New

York,

10021
Hewlett-Packard
RMC

Sales

Division

236

East

75th

Street

(212)

879-2023

TWX,

710-581-4376

Rochester,

14625
Hewlett-Packard
Syracuse

Sales

Division

800

Linden

Avenue

(716)

381-4120

TWX,

716-221-1514

Poughkeepsie,

12601
Hewlett-Packard
Syracuse

Sales

Division

82

Washington

SI.

(914)

454-7330

TWX:

914452-7425

Syracuse,

13211
Hewlett-Packard
Syracuse

Sales

Division

Pickard

Bldg.,E.Molloy

Rd.

(315)

454-2486

TWX,

315-477-1375

NORTH CAROLINA

High

Point,

27262

Hewlett-Packard

Southern

Sales

Division

1923N.Main

Street

(919)

882-6873

TWX,

510-926-1516

OHIO

Cleveland,

44129

Hewlett-Packard

Crossley

Sales

Division

5579

Pearl

Road

(216)

884-9209

TWX,

216-888-0715

Dayton,

45409
Hewlett-Packard
Crossley

Sales

Division

1250W.Dorothy

Lane

(513)

299-3594

TWX,

513-944-0090

PENNSYLVANIA

Camp

Hill
Hewlett-Packard
Robinson

Sales

Division

(717)

737-6791

Philadelphia

Area

Hewlett-Packard

Robinson

Sales

Division

144

Elizabeth

Street

West

Conshohocken

19428

(215)

248-1600

and

828-6200

TWX:

215-828-3847

Pittsburgh

Area
Hewlett-Packard
Crossley

Sales

Division

2545

Moss

Side

Blvd.

Monroeville

15146

(412)

271-5227

TWX:

710-797-3650

TEXAS

Dallas,

75209
Hewlett-Packard
Southwest

Sales

Division

P.O.

Box

7166,

3605

Inwood

Rd.

(214)

357-1881

and

332-6667

TWX,

910-861-4081

Houston,

77027
Hewlett-Packard
Southwest

Sales

Division

P.O.

Box

22813,

4242

Richmond

Ave.

(713)

667-2407

TWX,

713-571-1353

UTAH

Salt

Lake

City,

84115
Hewlett-Packard
Lahana

Sales

Division

1482

Major

SI.
(80I)486-8166
TWX:

801-521-2604

VIRGINIA

Richmond,

23230
Hewlett-Packard
Southern

Sales

Division

2112

Spencer

Road

(703)

282-5451

TWX:

703-282-9986

WASHINGTON

Seattle

Area
Hewlett-Packard
Neely

Sales

Division

11656

N.E.8th

SI.

Bellevue

98004

(206)

GL4-3971

TWX:

910443-2303

CANADA

Montreal,

Quebec

Hewlett-Packard

(Canada)

Ltd.

8270

Mayrand

Street

(514)

735-2273

TWX,

61D-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

(416)

249-9196

TWX:

610492-2382

1-65

INTERNATIONAL SALES AND SERVICE OFFICES

•

ARGENTINA

MauricioA.Saurez
Telecommunicaciones

Carlos

Calvo

224,

Buenos

Aires

Tel:

30-6312

AUSTRALIA

Sample

Electronics

(Vic.l

Pty.

ltd.

9-11

Cremorne

Street

RichmondE.I,

Victoria

Tel:

42-4757(3lines)

Sample

Electronics

(N.S.W.l

Pty.

ltd.

4

Grose

Street,

Glebe,

Sydney

New

South

Wales

Tel:

69·6338(6lines)

AUSTRIA

Unilabor

G.m.b.H.

Rummelhardtgasse

6/3
Vienna
Tel:

426.181

BELGIUM

Hewlett·Packard

Benelux

SA

20-24

RuedeI'Hopital,

Brussels

Tel:

11.22.20

BRAZIL

Ciental

ImportacaoEComercio

ltda.

Rua

Cons.

Crispiniano,

69,

8.0And.,

Conj.

81,

Sao

Paulo

Tel:

32-4332

CANADA

Hewlett-Packard

(Canada)

ltd.

8270

Mayrand

Street

Montreal,

Quebec

(514)

735-2273

Hewlett-Packard

(Canada)

ltd.

1762

Carling

Avenue

Ottawa,

Ontario

(613)

722-8162

Hewlett-Packard

(Canada)

ltd.

1415

lawrence

Avenue

W.

Toronto,

Ontario

(416)

249-9196

CHILE

Hector

Calcagni

Casilla

13942
Santiago
Tel:

6.42.26

DENMARK

Tage

Olsen

A/S

Ronnegade

1

Copenhagen

~

Tel:

29.48.00

FINLAND

INTO

0 Y

P.O.Box

153

Meritullinkatu

11,

Helsinki

Tel:

66.39.09

and

35.125

FRANCE

Hewlett-Packard

France

150

Boulevard

Massena

Paris

13e

Tel:

707.97.19

GERMANY

Hewlett-Packard

V.m.b.H.

Steindamm

35,

Hamburg

Tel:

24.05.51

Hewlett-Packard

V.m.b.H.

Kurhessenstrasse

95

FrankfurtamMain

Tel:

52.00.36

Hewlett-Packard

V.m.b.H.

Reginfriedstrasse

13

Munich

9

Tel:

49.51.21/22

Hewlett-Packard

Vm.b.H.

Technisches

Bura

Herrenbergerstrasse

110

703

Boblingen,

Wurttemberg

Tel:

6971

GREECE

K.

Karayannis

Klaftmonos

Square,

Athens

124

Tel:

230.30I(5

lines)

INDIA

The

Scientific

Instrument

Company,

ld.

6,

Tej

Bahadur

Sapru

Road,

Allahabad

1

Tel:

2451

The

Scientific

Instrument

Company,

ld.

240,

Dr.

Dadabhai

Naoroji

Road,

Bombay

1

Tel:

26·2642

The

Scientific

Instrument

Company,

ld.

11,

Esplanade

East,

Calcutta

1

Tel:

23·4129

The

Scientific

Instrument

Company,

ld.

30,

Mount

Road,

Madras

2

Tel:

86339

The

Scientific

Instrument

Company,

ld.

B-7,

Ajmeri

Gate

Extn.,

New

Delhi

1

Tel:

271053

IRAN

Telecom

ltd.

P.O.Box

1812,

Tehran

Tel:

43850,

48111

ISRAEL

Electronics&Engineering

ltd.

16

Kremenetski

St.,

Tel

Aviv

Tel:

35021(3lines)

ITALY

Hewlett-Packard

Italiana

S.p.A.

Viale

lunigiana

46,MiIan

Tel:

69.15.84/5/6

Hewlett-Packard

Italiana

S.p.A.

Piaua

Marconi,

25

Roma-Eur

Tel:

59.25.44/5

JAPAN

Yokogawa·Hewlett-Packard

ltd.

2270

Ishikawa-cho

Hachioji,

Tokyo

Tel:

Hachioji

0426-3-1231

(J9

lines)

Yokogawa·Hewlett-Packard

ltd.

No.3,

6·chome,

Aoyama-Kitamachi

Akasaka,

Minato·ku,

Tokyo

Tel:

403-0073,

403-0074,

403-0075

Yokogawa-Hewlett-Packard

ltd.

No.8,

Umeda,

Kita-ku,

Osaka

City

Tel:

361·3084,

341-2095

Yokogawa·Hewlett-Packard

ltd.

No.4,

3-chome,

Himeikedori,

Chigusa-ku,

Nagoya

City

Tel:

75-8545

KOREA

American

Trading

Company,

Korea,

ltd.

112·35Sokong-Dong

SeoulP.O.

Box

1103
Seoul
Tel:

3-7049,

3-7613

NETHERLANDS

Hewlett·Packard

Benelux

N.V.

23

Burg

Roellstraat,

Amsterdam

W.

Tel:

(o20l

13.28.98

and

13.54.99

NEW ZEALAND

Sample

Electronics

(N.

Z.l

ltd.

8

Matipo

Street

Onehunga

S.E.5,

Auckland

Tel:

565-361

NORWAY

Morgenstierne&Co.

AlS

Ingenj~rfirma

6

Wessels

Gate,

Oslo

Tel:201635

PORTUGAL

Telectra
Rua

RodrigodaFonseca

103

P.O.Box

2531
lisbon 1
Tel:

686072

and686073and6860

74

PUERTO RICO & VIRGIN ISLANDS

San

Juan

Electronics,

Inc.

150

Poncedeleon,

Stop

3

P.O.Box

5167
Pta.deTierra

Sta.,

San

Juan

00906

Tel:

722-3342,

724-4406

SPAIN

ATAIO,

Ingenieros

A.

Aguilera,

No.8,

Madrid

15

Tel:

223.27.42,

223.41.71,

and

224.84.97

SOUTH AFRICA

F.H.Flanter&Co.

(Pty.),

ltd.

Rosella

House

Buitencingle

Street,

Cape

Town

Tel:

3-3817

SWEDEN

H-P

Instrument

AB

Centralvagen

28,

Solna

Centrum

Tel:

08-83.08.30

and

10·83.08.30

SWITZERLAND

Max

Pual

Frey
Wankdorffeldstrasse

66,

Bern

Tel:

(031)

42.00.78

TAIWAN (FORMOSA)

Hwa

Sheng

Electronic

Co.,

ltd.

21

Nanking

West

Road,

Taipei

Tel:

4·6076,

4-5936

TURKEY

TElEKOM

Engineering

Bureau

P.O.

Box

376--Gal~ta,

Istanbul

Tel:

49.40.40

UNITED

KINGDOM

Hewlett-Packard

ltd.

Dallas

Road

Bedford,

England

Tel:

Bedford

68052

VENEZUELA

Citec,C.A.
Edit.

Arisan·Of

#4

Avda.

FranciscodeMiranda·Chacaito

Apartado

del

Este

10.837,

Caracas

Tel:

71.88.05

YUGOSLAVIA

Belram

SA

83

Av.

des

Mimosas

Brussels

15,

Belgium

Tel:

35.29.58

•

IN

EUROPE

Hewlett·Packard,S.A.
54

Route

des

Acacias

Geneva,

Switzerland

Telephone:

(022)

42.81.50

Telex:

2.24.86

Cable:

HEWPACKSA

1-65

For

Sales

and

Service AssistanceinAreas

IN

LATIN AMERICA

Hewlett-Packard

Inter-Americas

1501

Page

Mill

Road

Palo

Alto,

California

94304,

U.S.A.

Telephone:

(415)

326-7000

TWX:

910-373-1267

Telex:

033811

Cable:

HEWPACK

Not Listed Contact:

ELSEWHERE

Hewlett-Packard

International

Marketing

Department

1501

Page

Mill

Road

Palo

Alto,

California

94304,

U.S.A.

Telephone:

(415)

326-7000

TWX·

910·373-1267

Telex:

033811

Cable:

HEWPACK

•

•

HEWLETT",

PACKARD

CERTIFICATION

The

Hewlett-Packard Company certifies

that

this instrument was
thoroughly tested and inspected and found to meet its published
specifications when

it

was shipped from

the

factory.

The

Hewlett-

PackardCompany further certifies

that

itscalibration measurements

are traceable to the

U.

S. National Bureau ofStandards to the

extent

allowed by theBureau's calibration facility.

WARRANTY

AND

ASSISTANCE

All

Hewlett-Packard

products

are

warranted

against

defects

in

materials

and

workmanship.

This

warranty

applies for oneyearfrom

the

date

ofdelivery,or,inthe

caseof certainmajor componentslisted

in

the

operating manual, for

the

specified period.

We

will repair

or

replace products which provetobe defective during

the

warranty

period.

No

other

warranty

is expressed or implied.

We

are

not

liable

for consequential damages.

For

any

assistance contact your nearest Hewlett-Packard Sales

and

Service

Office.

Addresses

are

proviaedatthe

back of this manual.