Kenwood AG-252 User manual

OSCILLATOR
/v:-;-252
INSTRUCTION MANUAL
KENWOODCORPORATION
©PRINTED ll\PAN

CONTENTS
1. FEATURES 3
2.SPECIFICATIONS3
3.PANELEXPLANATION5
FRONTPANEL6
REAR PANEL. 7
4.PRECAUTIONSFORUSE7
5.OPERATING PROCEDURES 8
6.APPLICATIONS10
7.MAINTENANCE14
2
A product of
KENWOODCORPORATION
17-5, 2-chome, Shibuya, Shibuya-ku, Tokyo 150,Japan

1. FEATURES
1. FrequenciesgeneratedbytheAG-252rangeover
a broad bandwidth of10Hzto1MHz, with a low
distortion of0.004%(Typical)(1kHz,x100range).
2. Output voltageis5Vrmsor more at60012load.
Desiredvoltagescanbetakenoutcontinuously
with an attenuator (10dBsteps,6 ranges)anda
controller.
3. Output impedanceislow(600O).The attenuator
is guaranteedfora high accuracyof+ 1.0dBat
60012 load.
4. A selectorswitchallowsan easy selectionbetween
sineandsquarewaveforms.
5. Anaccuratefrequencysignalis obtained by syn-
chronizing with anexternalsignalusinganexter-
nalsync input terminal.
2. SPECIFICATIONS
3
[Sinewavecharacteristics]
Oscillationfrequency:
;x 1 range: 10Hz~100Hz
x 10range: 100Hz~lkHz
xlOOrange: 1kHz~10kHz
x Ikrenge: 10kHz—100kHz
x10krange: 100kHz~1MHz
Frequencyaccuracy: ±(3%+lHz)
Output impedance: Approx.60012
Output attenuator :
OdB, -10dB,-20dB,-30dB,
-40dB, -50dB(6levelsselectable;
(Accuracy at600Oload:±1dB)
Output voltage: ^5Vrms
(at600X1load)
Frequencyresponce: 30Hz~50kHz,±0.2dB
10Hz~1MHz,±0.5dB
Distortion : 1kHz0.004%(Typ)
(xlOOrange)
200Hz-20kHz0.008%
20Hz~ 100kHz0.04%
(100kHz:1krange)
10Hz~1MHz1.5%

4
Output voltage: ^10Vp-p
(at 600Oload)
Rise/fall time : ^200ns(atmaximum
output)
Duty ratio :
48 : 52
(at 1kHz,maximum output)
Sync range: ^± 1%/Vrms
Maximum input voltage:
15V (DC+ACpeak)
Input impedance Approx.100kO
Within specificationtemperature/humidityrange:
10~35°C,85%RH
Operationtemperature/humidityrange:
0~40°C,85%RH
Power voltage/frequency:
100/l20/220/240Vac ±10%
(Max. 250Vac), 50/60Hz
Power consumption: approx.5W
Casing :
212(W) x 133(H)x 272(D)mm
Max.:
212(W) x 156(H)x 312(D)mm
[Weight] Approx.3.8kg
[Accessories]
Output signalcable(CA-48):1
Power cable: 1
Instructionmanual: 1
Replacement fuse: 2
[Squarewavecharacteristics]
[External sync characteristics]
[Environmental]
[Powersource]
[Dimensions]

3. PANELEXPLANATION
Fig. 1 Front Panel
Fig. 2 RearPanel

Frontpanel
®Indexmark
Indicatesdialdivisions.
© Scale plate
Calibrated with 10—100divisions.
@ Frequencydial
Adjustsoscillation, frequency.
Frequency canbereaddirectlyby multiplying the
indication onthescaleplatebythemagnification
ofthe FREQ. RANGE switch.
© POWER
The powerswitch.Whendepressed,thepoweris
appliedtotheAG-252.Pressingtheswitchagain
makes itreleasedandturnsthepoweroff.
©Pilotlamp
Indicates that thepowerisapplied.
© FREQ. RANGE (Hz)
These switchesprovidefiveselectionsofoscillation
frequencyrange:
x 1 : 10Hz~100Hz
xlO: 100Hz~lkHz
xlOO: 1kHz~l0kHz
x 1k: 10kHz-100kHz
xlOk: 100kHz-1MHz
®WAVEFORM
Selects a waveformof output signal.When
depressed, itselectssinewave(— ).
Whenreleased,itselectssquarewave(Ij).
© OUTPUT
Delivers output signalinsineorsquarewaveform
whicheverisselected.Theonelabeled£ isthe
GND (case GND)terminal.
© ATTENUATOR (dB)
Attenuatesthe output tooneofsixlevels:
0to-50dBinstepsof10dB.
©AMPLITUDE
A controller continuouslychangingthe amplitude
of output voltage.
6

Rear panel
© SYNC
An input terminalforanexternal sync signal.
When synchronizingtheAG-252 with anexternal
signal, applythe sync signaltothisterminal.
The terminallabeled1 istheGNDterminal.
© Fuse holder/Linevoltageselector
The fuseinthefuseholderisratedat0.3Afor
100/120V type,or0.2Afor220/240Vtype.
To changethepowervoltage,unplugthepower
cord from thepowersocket,thenswitchtothe
requiredvoltage.(See "MAINTENANCE" for
details.)
4. PRECAUTIONS FORUSE
1. Ensure that10Vrmsorhighervoltageisnot
appliedtothe OUTPUT or SYNC terminals.
When DCvoltageisapplied,makea connection
via a capacitor.
2. Useshortconnecting leads. Longshieldwires
would cause amplitudecharacteristicstobe
changed bythecapacitybetweenshieldwires.
Ordinary leads, iflong,alsotendtopickup
inducednoise.Longleadsofanytype cause
various troubles.
3. Connectthepowercordaftercheckingthatthe
powervoltagetouseiscorrect.Thepower
voltageshouldbe within ± 10%oftherated
voltage.
4. Oscillationlevelmaychangesoonafter turning
the FREQ. DIALorpressinga FREQ. RANGE
switch. Itisnotanaccident.
5. Besureto press one FREQ. RANGE switchat
a time.Notethatthefunctionwillnotoperate
correctlyifmorethanone button ispressedat
a timeorallthebuttonsare released.
7

5.OPERATING PROCEDURES
Whenconnectinganinstrumenttothe OUTPUT
terminal,firstmatchit with the output imped-
ance (600O)ofthe AG-252.-
Whenthe SYNC terminalisunused,always
attacha shortbartotheterminal.
Otherwise, externalnoisemaybedrawn from
the SYNC terminalandsuperimposedonthe
output.
The ON/OFF switchof unit isdesignedtoact
onthesecondarysideofthepowertransformer.
The primarysideofthetransformerremains
energizedevenifthe ON/OFF switchissetto
OFF. Therefore,ifthe unit istobeunusedfor
a longtime,thepowercordshouldbeunplugged
from thereceptacle outlet.
1. Starting
Connect theaccessorypowercabletotheAC
socket aftercheckingthatyourpowervoltageis
within ±10%of 100Vac. Thenpressthe POWER
switch® toapplythepower.Oncethepower
is applied,the pilot lampisonandtheAG-252
is inactivestate.Agetheinstrumentfor20to
30 minutes until theoperationbecomesstable.
2. Selectingan output waveform
If output ofsinewaveisrequired,pressandlock
the WAVE FORM switch©.If output ofsquare
wave isrequired,pressagainandreleasethe
switch.
3. Settinga frequency
Select a requiredfrequencyrange with the FREQ.
RANGE switches©.Then turn the FREQ. DIAL
(3) toadjustthedesiredfrequencytotheindex
markCD.
.Example: Settingfrequencyto1.5kHz
1) Selectthe FREQ. RANGE switches© labeled
X100.

2) Turnthe FREQ. DIAL© toalign"15"on
the scale platetotheindexmark®.
Now1.5kHzhasbeenselected.
15 x 100= 1500Hz= 1.5kHz
4. Adjustingthe output voltage
The voltage output tothe OUTPUT terminal@,
whethersineorsquarewave,canbecontinuously
varied with the AMPLITUDE © andsteppeddown
with the ATTENUATOR ®.
Example : Adjusting output voltagetolOmVrms
1) Connecta voltmetercapableofmeasuring
1Vrms ofACvoltagetothe OUTPUT
terminal®.
2) Setthe ATTENUATOR © OdBandadjust
the AMPLITUDE © sothatthevoltmeter
may indicate1Vrms.Nowa IVrmsvoltage
is output tothe OUTPUT ®.
3) Setthe ATTENUATOR © to-40dB.The
voltmeterindicatesnearly0V,butinfact
thevoltageof10mVrmsiscorrectly output
tothe OUTPUT ®.
5. Howtousethe sync input terminal
OscillationfrequencygeneratedintheAG-252can
besynchronized with anexternalsignalbyapplying
an externalsinewavetothe SYNC terminal©
ontherearpanel.The sync rangeismorethan
1% per1Vrms input, with thecharacteristicsas
shownbelow:
External sync input voltage[Vrms]
Notethathighervoltagesof sync signal(^2Vrms)
results inlargeramplitude,whichmay cause
clippingofwaveformorlargerdistortion.
9
Oscillation
frequency
deviation
[%]
Fig. 3

6. APPLICATIONS
Also remember thattheinstrumentmaybedam-
aged ifvoltageofmorethan10Vrmsisapplied.
Ifa DCcomponentismixedinthesinewave
inputfromoutside,removeitwitha capacitor.
6-1Usingas Sine WaveOscillator
AG-252 canbeusedasa sinewaveoscillatoras
outlinedbelow.
1. Since theunitfeatureslowdistortionfactor,it
can beusedformeasurementofdistortionchar-
acteristic ofamplifier.
2. Since theunitfeatureswidebandwidth,itcan
be usedformeasurementoffrequencycharacter-
istic ofamplifier.
3. The built-in high accuracy attenuatorpermits
measurement ofamplifiergain.
4. Canbeusedasa signal"sourceofimpedance
bridge.
6-1-1MeasurementofAmplifierGain
An exampleofmeasurementofamplifiergainis
described below.
First connect AG-252, amplifiertobetestedand
AC volt-meterasshowninFig.4 .
1)Adjust ATTENUATOR ® and AMPLITUDE ©
so thatACvolt-meterindicatestherated output

AG-252
AC voltmeter
Fig. 4
11
(supposed tobe1Vinthisexample)ofthe
amplifier.Tofacilitatethemeasurement,itis
advisable toset ATTENUATOR ® aslowas
possible. Assume that ATTENUATOR ® isset
-50dB fortherated output.
2) DisconnecttheamplifierandconnecttheAC
volt-meterto AG-252 tomeasurethe output
voltage. Notethattheuseof ATTENUATOR
® eliminatestheneedforconnectinga high
sensitivity volt-mater.If ATTENUATOR ® is
set toGdBandthevoltmeterindicates2V,it
means thattheinputvoltageoftheamplifier
is 50dBbelow2V.Therefore,thegainobtained
is asfollows:
IV
50dB + 20Iog10dB
= 50dB- 6dB
= 44dB
Amplifier
undertest

6-1-2Measurementof Phase Characteristic
Connect AG-252andanoscilloscopetotheampli-
fiertobetestedasshowninFig.5 . Ifthereis
nophaseshiftaboutthe output signalofthe
amplifier,theoscilloscopewilldisplaya straight
lineasshowninFig.5A. Ifthestraightlineon
theoscilloscopeiscurvedatitstopand bottom
sections asshowninFig.5B. itindicatesthat
the output signalofamplifierissuffering from
an amplitudedistortion.Inthis case, reducethe
output levelofAG-252a little tovarythefre-
quency. This causes thestraightlineontheoscil-
loscopetoexpandgraduallyto turn into anellipse.
By utilizingtheconfigurationofthisellipse,the
phase shiftcanbecalculatedasfollows:
First, measurethemaximumhorizontaldeflection
andsupposethatthisdeflectionis"X"andthat
thesectionatwhichtheellipse crosses thehorizon-
tal axis is"x",asshowninFig.6 . And,the
phase shiftangle6 isgivenbythefollowing.
Sin e =
A
Find 6 from thetableoftrigonometricfunctions
andthevalueobtainedgivestheangleofphase
shift.
Amplitudedistortion
onboth sides
Fig. 5 Measurementof Phase Characteristic
Fig. 6 Checkof Phase ShiftAngle
Amplifier
under
test
Oscilloscope
Noamplitude
distortion
0°45°90°135°180°
315°270°225°

6-1-3 UsingasSquareWarn Oscillator
AG-252 featuresexcellentrisingandfallingchar-
acteristics (120nsasstandardcharacteristic).
Ithasnocouplingcapacitorsinthe output stage,
so thesag(deflectionoftopsection)isaslow
as 5%at50Hz.Byapplyingsucha good square
wave toanamplifier input, variouscharacteristics
ofamplifiercanbeobservedonanoscilloscope.
To testanamplifier,proceedasfollows:
1) ConnectAG-252anamplifiertobetestedand
an oscilloscopeasshowninFig.7 ..
2) Press WAVE FORM ® tothe" " position
toobtainsquarewavesofappropriatefrequency
and: amplitude.
3) Duringthetest,changethefrequencyas neces
sary. Therelationshipbetweenwaveformsand
amplifiercharacteristicsisshowninFig.8 .
AG-252
Output
Waveform
Oscilloscope
Amplifier
undertest
.Fig. 7
Amplifier
.Characteristic
Flat frequencycharacteristic
over 10timestheinput
frequency.
Frequency ofabout10times
theinputfrequencyiscut
off.
Frequency ofabout1/10of
theinputfrequencyiscut
off.
Peak appearsonfrequency
ofabout10timestheinput
frequency.
Fig. 8
13

7.MAINTENANCE
Caution: Read thispagecarefullytokeepyoursafety.
For ElectricShockProtection: Besuretodisconnect
thepowercable from thesocketbeforeconductingthe
following operation.
REPLACING THE FUSE
In case thefusehasblown,locatethe cause. Ifthe
fuse itselfisthe cause, replaceitasfollows:
1. Pullthe plug ofthepowercord from thepower
outlet.
2. Removethefuseholderintherearpanelusing
a standardscrewdriver(seeFig.6 ).
3. Take outthe blown fuse,andinitsplace,insert
a newfuse.
4. Setthelabelofyourlinevoltagetothemark•,
then plug thefuseholdercontainigthenewfuse
into therearpanel.
CHANGINGTHE SUPPLY VOLTAGE
Remove thefuseholderintherearpanelusinga
standardscrewdriver.Thensetthelabelofyourline
voltagetothemark• and plug thefuseholder
back into place.Whenchangingthesupplysetting
from 100/120Vto220/240V,changethe0.3Afusefor
a 0.2Aone.(seeFig.6 ).
Fuse holder
Fig. 9
14