HP 204B Service manual

OPERATING

AND

SERVICE

MANUAL

MODEL

SERIALS

PREFIXED:

2048

OSCILLATOR

416-

01369-4

Printed:

JUHE

1964

Mode1204B

Index

SECTION

I

GENERAL

II

INFORMATION

INSTALLATION

III

OPERATION

01369-1

SECTION

IV

PRINCIPLES

V

MAINTENANCE

VI REPLACEABLE

OF

OPERATION

PARTS

Iii

Model 204B

TAau

0'

CONTENTS

TableofContents

ListofIllustrations

ListofTables

Section

I GENERAL INFORMATION.

1'-1.

1-4.

1-6.

1-8.

1-10.

INSTALLATION

U

2-1.

2-4. 2-6. 2-8. 2-10. 2-12. 2-16.

OPERATION.

10

3-1. 3-3. 3-5. 3-10.

3-16. 3-20. 3-26.

PRINCIPLES

'V

4-1. 4-7. 4-13.

Introduction Power

Mercury Accessories Instrument

Inspection

Rack/Bench

Combining Adapter

Battery-Powered AC-Powered

Repackaging

Introduction

Procedure.

General

Operation

Batteries

Recharging

Batteries.

Cycle-LifeofNickel-Cadmium

Batteries.

Mercury

Introduction

Oscillator

Peak

Detector

. . .

Supply

and

Rechargeable

Available

Identification

.

Instructions

Frame.

Oscillators

lor

.

Operating

With

Battery

OF

OPERATION. Circuit

Case.

Oscillators

Shipment.

Rechargeable Nickel-Cadmiwn

. . . . .

Replacement.

Batteries

Considerations

Page

'-1 '-1

• -1

.

1-' 1-' '-1

2-1 2-1 2-' 2_'

2-' 2-' 2-1 2-2

3-1 3-1

3

_1

3-1 3-. 3-2 3-2

3

-2

4-' 4-' 4-'

4-2

SecUon V (Cont'd)

Performance

5-5. 5-7.

~-8

5-9. 5-10. 5_12. 5-14. 5-16. 5-18.

5-19. 5-23.

5-26, 5-28. 5-29.

5-3l. 5-32. 5-34.

5-36. 5-38.

5-40. 5-42.

5-45.

Dial

Frequency

.

Output

Distortion

Repair

Cover

Servicing Troubleshooting. Adjustment

AC Battery

Adjustment DC Distortlon Frequency

Adjustments

Replacement

Cam Frequency

Replacement.

Range Switch

Replacement Battery-Pack AC

Power

Rechargeable

Supply . ReplacementofRechargeable

Batteries

Accuracy

Voltage

.

Removal

EtchedCircuit

and

Power

Charger

B:41.

Adjustment

Cable

Supply

.•

Checks.

Check

Response

Check

CaUbration

Supply

.

Check

Calibration Procedures.

Replacement

Potentiometer

Assembly Power Battery

. • .

and

Check.

.

Checks.

Current

.

..•

Supply.

Power

..

Boards.

• .. . .

..

Page

5-1 5-1

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

5-4 5·4

5-5 5-5

5-5 5-6 5-6

5-6 5-7

5-6 5-8

5-8

.

5·8

MAINTENANCE

V

5-1. 5-3.

Number 1-1.

3-1. 3-2. 4-1.

4-2. 4-3.

Number 1-1. 5·1. 5-2.

2-1. 2-2.

2-3. 2-4.

5-1. 5-2.

Speciflcations Required Dial

Model 204B Combining StepstoPlace

Combining

Adapter

TwoSubmodule

Front

and

Rear

Mercury Block Simplified

RC

Test

Distortion Test

and

Introduction Required

Panel

Operating

View of Model 204B Showing

Diagram

Network

Setup Setup

Output

Accuracy

Test

OscUlator

Case

Instrument

Case

Frame

Instrument

UnitsinRack

Controls,

Instructions

Batteries

•..•.•....

Schematic

Characteristics

for

Dial

Checks

for

Frequency

Voltage

.....

Test

Equipment

. . . . ,

Equipment

.

....

Into

. . . . . . . . .

Combinations

Adapter.

Connectors

Installed. Diagram

Accuracy

...•...

Response

Check.

...

..

...

or

. . . •

LIST

5-1 5-1 5-1

O'

ILLUSTRATIONS

Page

1-0 2-0

2-0 2-1 2-2

3-0

3·2 4-'

4-2 4-2

5-1 5-2

LIST

0'

TAlLIS

Page

.-.

.

5-1

.

5-2

VI

REPLACEABLE 6-1, 6-2.

Number

5-3.

Cover

5-4.

Model 204B, Exploded View . 5-4

5-5.

Cams

5-6.

Range

5-

'7.

Rear

5-8. 5-9.

5·10.

5-11.

5-12.

Number 5-3. 6-1. 6-2,

Model 204B AC Rear

Battery

Oscillator

Pack

Option 02

Rechargeable

Option01AC

Troubleshooting Index by Replaceable

PARTS Introduction Ordering

Removal.

and

Switch

ViewofBattery-Powered

Power

Internal

Power

Information

Cable

Detail.

.......•..

Supply

ViewofRechargeable

Power

and

AmpUfler

Supply

Power

Batteries

Power

Reference

Parts

..

. . . .

..

.. . .

Relationship.

....

Installation.

Supply

Summary

.••..

Supply

Supply.

Designator

.....

...•....

with

..

Battery

,

6-' 6-'

6-'

Page

5-3 5-6

5·7 5-8

5-8

· 5-10

· 5-11

· 5-12

· 5-13

Page

5

-5

6-2 6-5

v

Model204B

SECTION I

Paragraphs

Section I

1-1to1-11

1-1.

INTRODUCTION.

1-2.

The

Model 204B

transistorized

battery-powered

duces sine_wave

The

outputis10milliwatts tinuously' the within from

1-3.

adjustable

rated

load of 600

±3%,

The

power

line ground and

The800-ohm

signalsinthe

oscillator

Oscillator

overatleast

ohms,

output makesitcompatible with distribution oscillatorisuseful for Model403A/B makes

systems.

isolated

AC

Voltmeter.

an ideal companion

204B.

1·4,

POWER

1-5.

Normally

tery

pack

batteries.

which

If

SUPPLY.

the

oscillator

consists

operation

from power supply (Option1)or chargeable of

these

areinkit

and packisalso

suppl1es mount

and can be

1-6.

1-7. ventedtoprevent

batteries

power

supplies

form

in kit

in

easily

MERCURY BATTERIES.

Mercury

batteries

(Option2)may

operate

for field

form.

the

same

interchangedinthe

AND

excessive

GENERAL

(f1gure

instrument

5-cps

to

560_kc

into 600

outputisfloating,

instrument

impedanceofthe transmission When

instrument

of four 6. 75-volt

a power supply with

AU

location

RECHARGEABLE

usedinthe

internal

ohms

a 40-db

frequency

lines

battery-powered,

applications.

also

battery-powered,

for

is equipped with a

AC

is

desired,

be

from

115or230 volts,

installation.

three

types

inthe

field.

Battery

pressures

1-1)

which

range.

andiscon-

range.

response

isolated

chassis.

oscillator

and many

The ~

the

Model

mercury

an

used. Both

Thebattery

of power

instrument

Pack

INFORMATION

developing.

ed

but

presentnoproblemifproperly

is

a

pro-

Into

is

the

bat-

AC

re-

are

from

III). The

either

type of

a.

DO

b.

Disposeofbatteries exhausted

specifications.

c.

Never

d.

Turn in

e.

Store

1-8.

OPTIONS

1-9.

The

ableinkit

Battery AC

Operated

Rechargeable

1·10.

1-11.

Hewlett-Packard

digit

serial digitsofthe agree change differences 204B

describedinthis

The

nickel cadmium

follOWing

battery:

NOT

short

or

disposeofbatteries

off

battery

use.

batteriesina cool

following form

for

Pack

Power

Battery

INSTRUMENT

number

serial

with

those

sheets

supplied with

between your

batteries

used

(see

precautions

circuit

shouldbefollowedior

either

type of

battery.

promptly when

will not

operate

by

equipment up

fire.

powered equipment when not

well-ventilated

AVAILABLE.

three

power suppUes

field

installation:

Supply - 204B-64B

Supply -

Power

IDENTIFICATION,

204B-llA

Supply.

204B-llC

usedatwo·section,

(000-00000). numberonyour on

the

title

instrument

If

the

first

instrument

pageofthis

the

manual will define

and

manual.

are

they

are

manual,

the

seal-

Section

have

to

place.

avail-

eight-

three

do not

Model

FREQUENCY RANGE: 5 cps

vernier

DIAL ACCURACY:

control

±3%

FREQUENCY RESPONSE: OUTPUT IMPEDANCE: 600 OUTPUT:

5

vrms

10

milliwatts

open

clrcuit,

(2. 5

completely floating

OUTPUT CONTROL: Continuously

"TOO

attenuator

with at

least

01369-4

to

±3%.

ohms

vrms)

40-db

Table

560 kc in 5

with

rated

into

600

variable

range

I-I.

ranges.

load

ohms,

bridged

Specifications

DISTORTION: NOISE:

Less

POWER SOURCE: 4

7-ma

drain,

DIMENSIONS: Module

wide,

8

NET WEIGHT:

EQUIPMENT

Kit for field able

Battery

2048-64B.

Less

than

1%

than

Ufe at

in.

deep

6 lb

AV

installation,

0.05%.acor batteries

least

6-3/32

AlLABL'E:

Supply Kit

battery

at

8.75

300

hours.

In. high,

204B-llA.

204B-llC

for

field

Battery Kit for field installation.

operated

volts each,

5-1/8

in.

AC

Supply

Recharge-

installation,

1-1

Model204B

2-1.

INSPECTION.

SECTION II

INSTALLATION

Paragraphs

Section

2-1to2-14

II

2-2.

Unpack the

it

for

signsofphysical

surfaces, proceed Shipment" manual.

2-3.

as

soonaspossible for dures

2-4.

2-5.

a

tilt

instrument.

ing,

following the

2-6.

2-7. full-module of submodule units full-module a bench model for figure a

1/3-module

either the

2-8. ADAPTER FRAME.

broken

as

sectionofthe

An

electrical

performance

for

incoming qual1ty-control

RACK/BENCH

The

Mode1204B1sshipped with

stand

remove

COMBIN1NG The

useofthe

2-Z

the

divider

instrument

knobs.

described

after

checks.

attached.

To

adapt

the

plastic

procedure

CASE.

combining

unit which

suchasthe

unit,

the

oritcanberack

combining

for

liZ-module

Wlit.

thereforeitis

right

or

left

assembly.

inspection shouldbeperformed

ready

the

case

combining

upon

receipt

damage

etc.Ifdamageisapparent,

in

the

warrantyinthe

receipt;

These

INSTRUCTIONS.

Model204Bfor

feet identifiedin figure 5-3 by

given in

accepts

case

units.

divider

suchasscratched

"Claim

see

are

inspection.

for

useasa

paragraph

showninfigure

varying

Model 204B. Being a

case

mounted.

are

given graphicaUy in

The

latch

and

for

Damage in

rearofthis

paragraph

good

test

plastic

bench-type

rack

combinations

canbeused

Instructions

Model 204B

necessary

when

inspect

proce-

feet

mount-

5-13

2-1isa

to

installing

5-5

and

(c).

as

use

2-10.

2-11. plied There placing To a graph

2-12.

2-13. POWER REQUIREMENTS, When 2048 battery ::1:10%.50to sourceis115 rear 230-volt number

2-14. POWER CABLE. ting Association panel fromanac supply equipped with a

cable

tacle,

is

power

BATTERY-POWERED

Power

from

are

convert

rechargeable

5-35.

has

panel,

personnel,

and

which, when plugged

grounds cable

for

four6.

no

special

battery-powered

for

operation

battery

AC-POWERED

anacpower supplyorthe

power

230

or

supply. a

IWO

volts.

so

that the

sourceisused,

appears.

the

(NEMA)

cabinet

power rechargeable

the

three-prong

FILLER

i \

OSCILLATORS.

battery~poweredoscillators

7:i-volt

be

line.

detachable.

Mallory

installation

oscillators

fromanac

power

OSCILLATORS.

sourceof115or230

cps

wtIl

set

the

number

place

For

National

recommends

groWlded when being

Instruments

battery

intoanappropriate

instrument.

connectoristhe ground pin.

PANEL

mercury

instructions power supply

supply.

be

required.

switch.

115

appears.

the switchsothat

the

protectionofopera-

Electrical

three-conductor

Manufacturers'

that

with

power supply

The

offset pin on

into

refertopara-

located on

the

is

sup-

batterles.

for

operation.

the

Model

rechargeable

volts

When the

the

If

the

instrument

operated

the

acpower

are

power

recep-

the

or

a

I

,

I (0

2-9.

The

adapter accepts ure areasfollows:

01369-3

any combinationofsubmodule

2-3);itcan only

a.

Place

adapter

as

shown in

b.

Stacksubmoduleunitsinframeasshown in

2 .

Place

c.

Place

two end

4 • and push submodule

d.

Insert and tighten frame.

e.

The

complete

mounting.

frameissimplyarack

be

rack

frame

vertically

step

1 •

spacer

screwsoneither

until

clamp

spacer

8ubmodule Wlits

assemblyIsnow

mounted.

flgure

between

clampsasshown in

units

sideofframe,

frame

that

units

(see

fig-

Instructions

on edge of bench 2-4.

step

units,

step

into

frame.

step

5

are

tight

ready

for

rack

3

in

0

10 10

10

I

Figure

2-3. Adapter

Combinations

Frame

~.!_,_u

Instrument

I (

Ie

0

I

2-1

Section Paragraphs

2-15.

ating three-prong pigtailOnthe

2-16.

II

To

preserve

the

instrument

REPACKING

2-15to2-17

the

protection

fromatwo-contact

to

two-prong

adaptertogrOWld.

FOR

feature

adapter

SHIPMENT.

and

when

outlet.

cannect

oper-

use

the

Model 2045

a

CD

ADAPTER

FRAME

2-17. aginganinstrument questions. facility.

able.Iforlglnai

purchased

and

ment in heavy inner

instrument metal

The

a.

Service

b.

container.

c.

bandstoseal

d.

ment",

If

Packard to number,

service

correspondence

model

serial

followingIsa

contact

Proceedasfollows:

Place

instrument

containerisnot

from

your

Office

If

original

paper

Usea

heavy

and

inner

Mark

shipping

"Fragile",

instrumentisto be

{or

Instrument

serial

or

repair

number

general

for

shipment.

your

local19sales

lnoriginal

nearest

(refertomaps

containerisnot

or

plasUc

cartonorwooden box to

container

the

shipping

container

etc.asappropriate.

Note

shippedtoHewlett-

serviceorrepair,

Identifying

number,

to be

identify

and

prefix.

serial

guide

If

officeorrepair

containerUavai-

available,itcan

Hewlett-Packard

in Appendix). used.

before

and

use

container.

with

"Delicate

atracha

owner,model

and

performed.

indicating

instrument

number,and

for

you

.....

rap

strong

In any

repack-

have

Sales

instru-

placing

house

tape

Instru-

tag

by

any

be

in

the

or

=---

~.

~-~

@ SPACER CLAMP

RETAINING SCREWS

Figure

2

-4.

in

Two

Rack

o

Submodule

Adapter

o

...----@

liZ

MOOULE

INSTRUMENT

Units

4

2-2

01369-3

Section

Figure

IJ]

3-1

Model 2048

Controls and COlUlectors

1.

For

selecting

frequency

osclllatorisinoperative.

On

indicator;

2. switch except

3.

For

selecting Dial position

calibration

OFF.

gives

second.

4.

5.

6. Output

7.

3

-0

Provides calibrated

For imum

~

is

fine frequency

with

selecting

desired

into 600 ohms).

terminals,

cabinet

groW1d

range.

glows in

all

frequency within

multiplied

InOFF

positions of RANGE

desired

by

RANGE

output frequency in

adjustment.

arrow

in verUcal position. output level

(10

floating; impedance, 600 O.

terminal.

Figure

3-1.

Front

position

range.

switch

cycles

Dial

mw

max-

Panel

Operaling

per

is

Operation

a.

Connect loadtoOUTPUT

b.

Select (3). Example: RANGE to XIK. quency1s20kc(20

c. Set AMPLITUDE

If

oscUlatoriseqtdpped with

ply turning AC

D1sconnect power two

Controls,

Connectors,

Instructions

frequency with

or

Rechargeable

RANGE

Power

power

Supply

supplies

RANGE

If

FREQ.

the

oscillator's

cpsxlK=20

(5)

for

desired

Note

Battery

switchtoOFF

or

Battery

cordtolurn

off.

and

600Q(6)terminals.

(1)

and FREQ.

is

set

to

20

and

output

fre-

kc).

power level.

AC

Power

does not

Charger

Sup-

Supply,

turn

off.

eitherofthese

Model 2048

paragraphs

SectionIII

3-1 to

3-15

3·1.

INTRODUCTION.

3-2. The Model 204B has four

one output

signal in the

connector

5-cps

positioning the FREQ

trols.

AMPLITUDE

Output power level

control

(see

to 560-kc rangeisselected

.•

which has A 115/230 volt switchison the llalors chargeable

3-3.

3-4. given in figure

3-S.

3-6, To lator, a blocking

are

equipped withanac

battery

PROCEDURE.

Operating

power supply.

instructions

3-1.

GENERAL CONSIDERATlON

prevent

OPERATING

damage to capacitor

operating

figure

3-1). A sinewave

RANGE, and VERNIER con-

is

controlled

atleast

rear

panel

power supplyorre-

for

the

Model 204B

S.

transistors

should be with the output when connecting to a load thereisa dc potential Is used, Initial capacitance-voltageproduct volts. exists

For

example, if a 20-voH potential

across

thp.

20v=200j..l.fv).

DO

NOT ACROSS OFF

LOADS

GROUND(.....)BY

current

load,

difference.

surge

usea10-j..I.f

When the

mustbelimited

less

than 200

capacitor

CAUTION

CONNECT THE OSCILLATOR

WHICH

ARE

REFERENCED

MORE VOLTS;H1GHERVOLTAGESWILL BREAK DOWN

3-7, When the Model 2048 is RANGE cillatortostabilize; for

stabilization sltions.1f FREQ. dialissweptattoo put voltage fluctuations will

resistorisusedasthe element).Ifsweep stopped,

COMPONENT INSULATION.

switchissettoXl,

allow20seconds

only a few

when SWitching to

occur

variable

speedisdecreasedorsweeping

oscillator

output

will

initially

seconds

other

fastarate,

(Since a wlrewound

frequency

stabilizeatits

leveL 3-8, To obtain maximum amplitude

battery-powered turn-on effect may during the

3-9. When

lopermit

causeasmuchasa1%change in amplitude first20minutes

operating

Nickel-Cadmium) the

recharging (Nickel-Cadmium

maximum

rmS open

ohms.

to

paragraph

cadmium

3·10.

3-11. for an

oscillator

circuitorless

For

batteries

OPERATION

BATTERIES.

ThereIsno

instrument

the

mercury

3-26,

osCillators,

battery

of operation.

from

batteries

output

becomes

than

battery

Charging

are

given in

WITH

change in the

in which the

wait20minutes

voltagetostabilize.

batteries

require

batteries

less

2.5

volts

replacement

Instructions

paragraph

RECHARGEABLE

operating

rechargeable

SECTION

OPERATION

controls

by the

a 40-db

usedinseries

THAN

turnedonand

are

stability

(Mercury

replacement

than 5. 0 volts

range.

whenoscl-

in the

oscil·

across

which

capacitor

microfarad-

difference

(lOj..l.f

±25

for

necessary

RANGE

determining

normal

from after

This

only) when

rms

into 600

data,

refer

for

nickel~

3~16,

procedure

battery

and

by

are

to a

os- po-

out-

or or

III

supply has been

installed. plypermitseitheracoperatiOnfor (selected sourcesorbattery

Battery

by switch

operation

only (with c08nected)isrequired (0

£l

andisrecommended

104 F (400C), 3-12.

Is ment and a

When the

removed

RANGE

from the

resistorisconnected the power supply. The operate power

as

long

source,

as

The put of the power supply, oscillator through the prevents

connected 3-13,Itis

nected to a power

will

x

assure

operationisreqUired. not cord

3-14.

the

section

to maintain a constant

batteries.

battery

discharge

toapower

recommended that the

source

preventseIf-discharge

a fully

In

use, partiCUlarly when operating with the power

charged

disconnected.

When fully charged, the

oscillator

for apprOXimately uousorintermltteJlt opesation provided they temperatureof81

F ±10 .Ifthe atedathigherorlower is

reducedasthe

temperature ed; approximatelY2B imately beyond of supplying

20

hoursat-4 F

these

extremes

their

characteristic

voltage.

is

3-15. adequate in mind when nal obtainedifthe a be to avoid direct avoid placing the surrounding internal

The +1220Fto_4

for

temperatures

moderate

ambient

storing,

sunlight

temperature.

most

users,

operating

in

instrumentisleft in the sun, even with

temperature.

other

thanfor a

instrument

equipment might

THE HERMETICALLY SEALED CELLS THESE BATTERIES DAMAGED REDUCED

OR

IF

EXPOSED

THEIR

TEMPERATURES, THIS DANGER INCREASES UNDER PROLONGED CONDITIONS.

However, this power

115/230 vac

on

rear)

50

to 1000 cps power

for

portable

charger

at

temperatures

at

temperatures

switchisturned

oscillator

portion

across

charger

the

power

reSistor,

cordisconnectedtoa

placed

actsasa loadInplace

A diode in the output

when the

source,

power

whenever pOSSible,

of the

battery

Turn

battery

the

oscillator

whenever

batteries

40

batteries

temperatures

extrIemes

h0:-ors

at

12J F (50

(-20

C).

At

the

batteries

stable

0

F

temperature

however, keep

under

field cOJlditiOns.

excess

of 122 F

Good

transporting,

very

short

in a location where

excessively

CAUTION

MAY

BE PERl\1ANENTLY

LIFE

TO

DRASTICALLY

EXTREMELY

sup~

±-10%

applications,

power

cord

diJi'-

below 32 F

above

OFF, power

of the

instru-

the output of

wlll continueto

across

the

out~

of the

charge

rate

circuit

oscillatorisnot

cord

be con-

This

cells

and will

portable

OFF

when

wilt

hours

power

of

contin~

areata

are

operp

their

capacity

are

approach-

0

C)orapprox-

temperatures

are

not capable

discharge

range

these

limits

Inter~

are

easily

practice

or

operating

period.

raise

would

Also

the

IN

HIGH

is

in

01369-4

3-1

Section III

Paragraphs

3-16

to 3-27

3-16. RECHARGING NICKEL-CADMIUM

BATTERIES.

3-17. discharged below 5. 0 volts

rms

much longer when

llator

sive

shorten

3-18.

connect power

batteries

hoursata

hoursata11milliampere

fully

be

20

charged,

time.

The

into

6000hms.

probably wHl not

discharge

their

To

recharge

will

discharged turnedonfor minutes.

the

The llatorisOFF CN!ase in

charging

mentisused

charge

current

adjustment maximum of charge. used high

3-19. ture ever,

Sho~ld

The

for

quick

rate

will

The

between

to obtain be

ione

(27C:1:5.6

batteries

should be

when maximum

rms

open

circuitorless

The

batteries

this

point Is

meet

of

batteries

lile.

batteries,turnoscillatorOFF

cord

to a

be

fully

chargedinapproximately

5.5

milliampeN!

at the beginning. use

alteraninitial

If

the

batteries

oscillator

charge

or

while the

circuit

canbeturnedonfor

rateisthe

operating;

time

will be

batteries

can

be

RI02

11

milliamperes

11

milliampere

charge

shorten

batterJes

+32

only. Repeated

battery

can

F to

+122

opthnum

atatemperature

C).

considered

oscillator

than2.5 volts

will not

reached

and

specifications.

may damage them

suitable

cllarge

power

charge

current currentifthey The

instrument

chargeofat

were

only

same

whether

therefore,

very

requiredifthe

are

being

increased

(refer

charge

to

with the

figure

provide

rate

life.

beochar&ed

at

an~

F (0 C to +50 C). How-

battery

life, techargl&g

of

80.6

CAUTION THE FOUR NICKEL-CADMIUM BATTERIES ARE

HERMETICALLY SEALED DAMAGED AT (500C). MENT

IF

CHARGED

A TEMPERATURE EXCEEDING 122 F

IF

THE CHARGE CURRENT ADJUST-

HAS

BEEN SET FOR A QUICK CHARGE

AT

AND

A FAST

RATE, PLACE THE INSTRUMENT

LOCATION WHERE THE

TE~PERATURE

(40 C),

3-20.

CYCLE-LIFE

DOES

OF

NOT EXCEED 104 F

NICKEL-CADMIUM

AMBIE~T

BATTERIES.

3-21. As the

cycle-Hfe

the

batteries h:.res decrease

may perature

3-22. ing charging than the maximum manufacturer,

3-23. The the 225 hour

extremesIntemperatures

(complete

Is reduced.

wHi

Increase

the

resultifthe

for

the

cycle-lUe.

batteries

a prolonged

Batterycycle-Hfe

before

the

and

discharging

batteries

and

by not

cycle-ltfe

manufacturerer,on

milliampere-hour

charge

and

discharge

charge-discharge

Storageathigh

self-discharge

Permanent

are

storedata high

period. canbe

extended by

are

completely

at a

ten·hour

rate

overcharging.

of

the

batteries

an

endpoint of

capacity.

currentof22.5

are

rate

battery

whichisslower

specified

80%

Thisiswith a

as

fully

output

drops

operate

the

osci-

Exces-

or

and

source.

The

60

and

30

were

can

least

partially

dis-

useatany

the

osci-

little

In-

instru-

recharged

charge

5-11) to a

a quick

should

chargingata

tempera-

F

:1:10

CAN

BE

RA!E

IN

A

approached,

cycles)

tempera-

and

also

damage

tern-

recharg-

discharged,

by the

is

based,

ofthe

rated

ten-

milliam-

be

F

of

by

peres

..vlth

discharge end voltage on

every

in

excess 3-24. When tor,

the

40

hour

if

they

cycle.

of 100

batteries

rate.

are

recharged

(t.

used

10

The

3-16. 3-25.

lowing a battery output cuit a quick erate connecting charging charging

3-26.

3-27. oscillator

circuitortess

vided the

batteries (Mallory 3-2,

(2.5Vrms

a.

cover

Optimum

simple

dischargebyrecharging

level

drops

into 600 ohms),2)keeping the

charge

to a minimum,3)0?erati.1Jatmod-

temperatures

power

with

oscillator

batteriesata quick

MERCURY

Battery

output

than2.5

DC

BALisadjusted

with

type TR235Rorequivalent).

and

proceedasfollows:

Remove top

from

instrument. b. Remove wing nuts c.

Remove and

paragraph

d.

polarity

1-6.

Install

matches

replacement

clamps.

e.

Replace

£.

Replace top

D!SIGNATION

Figure

battery

'OLA"ITV

3-2.

Mercury

carried

volts/cet!

Under

cycles

canbeexpected. topowerthe are

dischargedatapproximately

batteries

as

battery

to the

x 5'"5.50

these

conditions a

$I;

Model

are

not fully

recommended

life

can

normal

be

routine of1)preventing

before

below

5.0Vrrns

whenever

cord

after

BATTERY

replacement becomes

less

volts

turned

charge

rms

intoanopen

possible

60

hours

OFF

rate).

REPLACEMENT.

is

reqUIred

than

5.0

into 600

correctly.

four

6.75-volt

cover

retaining

and

mercury

battery

disposeofbatteries

batteries

polarity

clamps

designation

and wing

cover.

8ATTE"Y

ClJ;M?

Rear

View of Model 204B Showing

Batteries

Installed.

Model204B

ten-hour

volts!battery)

cycle-life

204BOscHla-

discharged

in pa.ragraph

obtained by fol-

complete

the

oscillator

cir-

use

and4)by

dis-

of continuous

(30

hours

whEen

the

volts

rms

open

ohms

pro-

Replace the

batteries

Refer

to figure

screw

and

slide

clamps.

according

so

that

battery

on

battery

nuts.

WING

'"

a

of

if

to

3-2

01369-2

Model204B

SECTION IV

Paragraphs

Section

4-1to4-10

IV

4·1.

INTRODUCTION.

4-2.

The

Model204B

lator

circuit,apeak attenuator front

in

the

4-3. bridge,atwo-stageampl1fier, ers. whichis1) and2)appliedtothe

4-4. selective work. positive

frequencyofoscillation.

er

networksupplies The difference

4-5. bridge sion

thereby

The

the

RC

(bridged-T

panel

controls

block

diagram,

The

He

The

output of

returned

The

RC

network

The

RC

feedbacktothe

output of

between

The

peak

oscillator

ratio

of

changing

peak

detector

oscillator

bridge

the

consists

detector

type).

associated

figure

bridge

frequency-selective

detector

oscillator

this

circuitisa

to

the

output

consists

andaresistive

amplifier

The

negative

amplifier

the

feedback

output

voltage

resistive

the

amountofnegative

with

the

outputata

PRINCIPLES OF

of an RC

circuit.

These

with

4-1.

consists

and two

RC

bridgeasfeedback,

attenuator.

of

an

voltage

and

resistive

feedbacktothe

is

proportional

signals.

detects

voltage

divider

changesinthe

and

network

constant

bridge andanoutput

circuits

them

are

emitter

sine-wave

He

frequency-

divider

network

determines

voltagedivid-

amplifier.

changes

divider

level.

oscil-

and

the

shown

of an

HC

follow-

signal

net-

supplies

the

to

the

RC

the

divi-

network,

feedback,

maintains

OPERATION

4-6.

The

attenuatorisa

provides

voltage

4-7.

4-8.

of

anHefrequency-selective

voltage

networkissimilartoone

resistive

4-9. age to

maintain shipatthe componentsinthe

4-10. series

and which X = R in

posltive~eedback

and1sin tage

Rw1llbeamplified;atfrequencies equalR,the right oscillation. curve

and

continuous

while

OSCILLATOR

The

RCbridge1nthe

divider

voltage

As

in any

(from

the

oscillations.

desired

The

frequency-selective

branch,

H2,

as

shown in

phase

(figure

phase

below

4-3).

andisinsufficientinamplitudetosustain

Figure

and

phase

the

maintaining

network.

divider,

oscillator,

oscUlator

bridge.

CI and

the

voltagetothe

with

Only

positive

relationship

frequency

bridged-T

controlofthe

constant

CIRCUIT.

oscillator

network

The

frequency-selective

legofa Wien

the

other

an

in-phase

circuit

frequencyismaintained

RI,

figure

series

the

oscillator

that

feedback

4-3

shows

where

output)isnecessary

The

proper

network

andaparallel

4-2.

For

and

parallel amplifierismaximum

frequencyatwhich X =

voltage

the

for

Xc =

attenuator oscillator

output

circuit

whereXdoes

frequencies

circuit

and a

bridge;

leg.

feedback

phase

consists

the

frequency

branches,

is

positive

R.

impedance.

consists

resistive

relation- bytheRC

branch,

output

bot

feedback

which

output

the

volt-

of a

C2

at

the

vol-

Rot

of

the

above

RC

BRIDGE

(RIQA,B,C2,c11

IVE

Q

,

k

,

Ci

RNIERI

, ,

"'>1

, ,

"

'

,

0

I

RANGEl

POSITIIIE

FEEDBACK

NEGATIVE

FEEDBACK

AMPLIFIERS

Figure

FEEDBACK

QI

,02

4-1.

Block

FOLLOWERS

Diagram

EMITTER

03,04

PEAK

DETECTOR

05

,CR6

~O.I-~·'.

!AMPLITUDE

ATTENUATOR

R40A.B If,

Q,

I

,

!OUTPUT I

h-<

,

, ,

,

r-'--<

•

01369-2

4·1

M.odel

204B

Paragraphs

Section IV

4-1to4-10

4·1.

attenuator Iront in the block

4-3. bridge.atwo-stageamplil1er, ers. whichis1) and

4-4. selective

work.

positive frequencyofoscillation. er The difference

thereby

The

the

INTRODUCTION,

4-2.

The

Mode1204Bconsistsofan

lator

circuit.apeak

(bridged-T

panel

The

Re

The

output of

2)

appliedtothe

The

RC

networkandaresistive

The

feedbacktothe

networksupplies

output of

between

4-5,

The

peak bridge sion

oscillator

ratio

peak

Re

oscillator

of

changing

detector

type). controls diagram,

returned

bridge

RC

the

associated

figure

bridge

frequency-selective

the

detector

oscillator

this

circuitisa

to

output

consists

amplifier

The

negativefeedback

amplifier

the

feedback

output voltage resistive

the

amount of

with

the

output at a

the

detects

PRINCIPLES OF

RCbridge

circuit,

These

4-1.

and two

RC

attenuator.

resistive

is

voltage

divider

constant

circuits

with

them

consists

emitter

sine-wave

bridgeasfeedback,

of

an RC

voltage

network

and

determines

tothe

proportional

signals.

changesinthe

and

changes

divider

negative

network

level.

SECTION

oscil-

and

an output

and

the

are

shown

of an RC

follow-

signal

frequency-

divider

voltagedivid-

net-

supplies

the

amplifier.

to

the

He

the

divi-

network,

feedback.

maintains

IV

OPERATION

4-6.

The

attenuatorisa provides voltage while

4-7,

4-8. ofanRe voltage

network

resistive 4-9.

age

to

maintain shipatthe components in

4-10. series and R2, which X positive andisin tage Rwiilbeamplified;atfrequencies equal R, the right oscUlation. curve and

continuous

maintaining

OSCILLATOR

The

RCbridgeinthe

frequency-selective

divider

is

voltage

As in any

(from

the

The

branch,

as

""

<feedback

phase

(figure 4-3), Only

phase

and

below

the

network.

similartoone

divider,

oscillator,

oscillator

oscillations.

desired

the

bridge.

frequency-selective

C1

and

shown in

R in

the

voltagetothe

with

positive

andisinsufficient in

Figure

phase

relationship

frequency

bridged-T

controlofthe

constant output impedance.

CIRCUIT,

osc1llator

network

The

legofa Wien

the

other

an

in-phase

circuit

The

proper

frequencyismaintained

R1, and a

figure4-2.

series

the

4-3

and

parallel

amplifierismaximum

oscillator

that

frequency at which X

feedback voltageisliot of

shows

for

where

Xc

attenuator oscillator

circuit

and a

frequency-selective

leg.

feedback

output)isnecessary

phase

network

parallel

For

amplitudetosustain

the

consistsofa

the

frequency at

branches.

circuit

where

positive

frequencies

=:

R.

consists

resistive

bridge;

relation- bytheRC

branch,

output

X docs

feedback

which

output

the

volt-

the

vol-

the

above

C2

::

Rot

RC

BRIDGE

(RI0A,B,e2,C7)

IVE

IfREQI

Q

(j

RNIERI

\

,

.

,

,>1

,

b

RANGEl

I

POSITIVE

fEEDBACK

NEGATIVE

fEEOBACK

AMPLIFIERS

Figure

FEEOBACK

01,02

4-1.

Block

FOLLOWERS

Diagram

EMITTER

03,04

PEAK

DETECTOR

05

,

00'-11>-1'"

lAMPLITUDEI

ATTENUATOR

,eRG

0,

R40A,B

,

m

10UTPUT I

h--<

, ,

,

.,r-<

01369-2

4-1