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Model 970



l80l w. BELTE'PtAlNE AVE.,



606 t 3


t=l LJ t= =t L-..] LI






Radio Analyst


W3t Belle Plaine Avenue



Chicago, Illinois 6O613




W}lat the Modet 970 Radio Analyst Will Do. Controb and Jacks: Identification and
Power Supply: Sp
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Desciption..... .. .

-,.6? . . - .

Volt Otm Meter: Specificatjons and Dscdpaion.....

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RF and and Audio Sction: Specificaiion and Descdption-..
Using ttle

9?O . .


FM Recciver Aligdent

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WarEnlJ S"^icF INrruclionq

trIODEL 970 RADIO ANALYST Vht't the xlodel 970 Rodio Analyst ViIl Do
Some idea of the inherent versatility of ihe Model 970 can be sanred


an exahina_

Th. Model

970 provides:

provjdes roliascs from zero to 15 volts, Even radios.mploying idpped power supplies mar- be iully operated fmm this bnilt in bias sou.ce. The available cor!.nt ft 5 amperes

1. IIC power supply for pow.rins the mdio rnder lesl. This uniquc power gupply

at all DC POWEE swiich posiiios, 5 mperes calibratcd at 6 \' AUTO, and 12 V AUTO, dd 1 dpere calibraid at all other non-automotive DC PO\ aER toltases.

2. Volt-obm mitliammete. (VOM)- 'fhe meier measures voltase, curent, and retrasistor lealase as selected bl the lunction switch. The. arc four ranges for measuribe voltage and currant, md ihrce mnses for measuing resistance. The meter is fully protected agaiNt a.cidenlai overloadins.
sistance. transistor Beia or

3. Ac.uraie "Out of Circuit" test lor irasisiors. Leakage and Beta are individually iested and rcad on special s.ales on the face of VOM. IFatage is read on the l-IiAKAGE scale. Beta is read dircctly on a 0 300 BE1A scal. Clip leads and a socket are lrailable on ihe hont pael for traroistor teslins. An NPN PNP swikh selects con hections for iransistor poladty. For the iirst iine in a low cost tester, a switch position is provi.led for testine power iransistors at working currenis.
.1. Built in "In Circuii" lransistor te6ier- Thi6 s.ction may bc Ncd a6 a D.C, sisnal T$.er lor reDidly localizing a dcad stage. The iesi is hade bv usibg the Dyna Tce

shich is single probe.

5. Sisnal scncmtor thai tunes frcm 250 lo 2000 lc, 10 io r 1.4 h., and 88 to 108 hc in rour ban.ls. The outpui telel lrom the gen.raior is lariable and mar. be used tor Signal Ir.jaiion or RI and IF alislnent. The generator operales with an intrnal400 cr.le hodulntion or umodulaied. BaDd A provides 250 to 750 lc AM hodulated. Band B provides 750 to 2000 kc ANI modnlatcd Band C provi.les 10 mc A\I or nM modu llied. Band D pmv es 8a |o 108 mc F\I modulatcd. 6. 400 .ycle sisnal at ihe front panel fu Sisnal Ihjection inio the Audio scciion of a ladio. Th. signal level is adjustalle by a lront pdel control.

ld.entili.ation and Functio.L
The Model 9?0 Railio Analyst is a compleie instiuenf for se in tt.le servicins of t.ansi6tor radios, but is equally applicable io battery powered vilraior typc or 115V AC/DC tube lypes. When Eing this new insfruhent for the first time, the best way ta become fuiliar sith thc controls ad sisnats is to make a dry run" on a known mdio. Caretutly observe the fiects of ihe ontrols and sismls. Ii is the puryose of this scction to familialize ihc technician with all of the operatins .onirols of th Analyst-


(S.he,nati. Srnbol)




io the varioN circuits and iurN on pilot lightselcci outpul voltaga of r% volt steps from 1%

posiiion swiich which applies AC linc rrower

Ten position seikh ibich enables operator lo

ih. DC

Power Supply rn



BrAS (R.49)

Vadable .esistor which provides a vadable out put from zero to the voltase selected by the DC POWER selecior swilch. This bi6 conirol is con' ceniric wiih ihe DC POWER *lector switch, bui

only controls ihe voltage a.cessible at the BIAS

oriT-rN cKT (5w4)


t,.-irion .u iich shi.h o!-r.r, , in , onjunfl iun with other 1BANSISI OR TEST 6wit he6, OtlT position i6 lor testine a lransistor independentlyIN CKT Dosition G lor tcstins a transi6tor while ii is conDected in a ciroit.


Tso po.iiion -wrh *hich stpli, " !roper bids lularirJ b r}e en rrr, l\p end .ollF.ror ol a transistor urder lest for both OUT and lN CLT
T\'o position switch which id PO\NXR TRANSISTOR TEST pu,irjun applrp- I Ahar ofara ihg cuncntB and in SIGNAL TRANSISTOR TEST ouT of circuit ilansi6ior t4i.


position appli$ lower ope.afing orrents to 1lansisior under tesl. Thtu swikh is used with ihe

IN CItICt]I'f ADJLST coARsE-lI:W (R.47).(R..lil)

Two laliable resisto.s used io position the metef

poinie. to


on metr



Red jack at lower lelt comer which suppli.s cur rarr lor al]pl..ariun in rlo basa ot a 1rtu,i"lu n tbe IN CKT le6t.

PANEL IIARKING (s.hemari. srnt'ot)


Tro po,i,ioh -hir.h sl:.n sel-.ls r)pc of OUT uI ,ircd, lraBiJor r.sr. Tn LLAK fnoi'i,n. h;Eh leakase btseen coliecior and ehitter (I.s) read6
BAD (red) on mter. In Beta pDsition, true value

ol B.ta is read on the 0 300 scale.
S"cl, I

a.,"p'. r\p

aa,'- ^r a rh.inor OUT of


(Rd, Yellow, lnd BIu Clip T,eids)

Olip leads for connecting to a ir.nsistor for OUT ol.ir.uii rp.r' ral .li! lFsd--dlrF-. ) pllow, r:r, lead-base, blue clip leadasi

Br,lS (J.rk)

R u- j..1, ^rrnh.u|l'Ii". fon'rollpd Dr- b,as rol from power supply.



Red and blacl jacks which supply DC voliage sel.led frcm the power supply.



seleci function ol the VOM.


"urLl \hi.l






Variable resistor which codtrcls meier cur.ent for adjrsting zro readins ol rcsistance scale.
Faciory set, requires no furlher adjstment.
Rcd and black jacks which provid. input connec'
Six position switch whjch enablcs operaior to turn ofi signal generator or select desned sigml band

(Socldrirer Adjustmnr) (n.36)

voll +


u4ND StrLtrCTOR (SV-l)


\ r|Jh ' Ba i rr'a.rro . 4 rl loin" I dn., oial fuf ri , .rin8 'B-o on,, bands. COARSI coDtrol sets approximatc f..

q(ency and concent c FINE control cires a


LEVEL (R-15)

Vsriable resistor which contrcls sirensth of signal appea ns at RF OIIT prob..

T\.u ronn-.ri.n
from AUDIO LEVDL (n-2r and S\1-2)

Rl' si$al


l"ub *l .h frurid"".om..lior"

VJriablc rc6i8ro- anJ oa off s$i(ch $hich codrrol audio output and RF modulation l.vcl.
Red and black jacks which providc outpnt con .ectian6 frcm audio oscillator,




^oor,NA"ro I.YsI

o L*n




o o
2-Pow.r sUpply Sedion, Fronr Pon.l.


OltTPltT: The DC POWER supply is adjustable in steps of 1.5 volts from 1.5 to l5 volb. {ivc ampercs is available at all setiings ot the DC POWER supply. At seilingg of 6 V AU1-O, ad 12 V AUTO, the clrlcrt js 5 mperes calibraied. Ai ail non auiomoi.ive voltage setlinss the currenl is 1 ampere calibraled. Across th. D(l OUT t.rminals is a BIAS conirol which provides a biasins voltasc that
caD be varied lrom 0 to 100% ol the value indicaied on the DC POWER seleciol switch by rotatins i.he contml countercloclwie. Clo.Lqise rotation varies the BIAS froh 100 io 0% of the DC POWER swit.h setiing.

RIPPI-E: Malimrm ripple

does not erceed 5%.

IUSFj: A 3 ampere Iuse protects lhe circuits at the primry of lhe power translormer. A 5 ampere luse proiects thc diodcs in th. pow.r sxpply-

l'he power supply seciion of Radio Analyst 970 provides the dc voltages for lransislof iestins and complctc opcratins and bias voltases fol a radio under tesi. For car radios use ihe 6 V AUTO or 12 V AUTO DositioN of the DC POWER s.lcctor sqitch. derrendils on lhe eleci.ical sJstem $.d in th. car. In some cases ihe dmin of ihe car Fdio may be lowcr or higher than average. The DC POWER scl.ctor 6witch can be used 1o change the voltaa. .ith.r np or down,



fis. 3-VON\ Sedion, rronr P.nel. 2V. 20V, 200V, 500V.



Within 5% ot lull
20 ma, 200 ma. 2

lvilhin 79i ol tutl scale. x t, x 10, x 100.



5 amp.

Within 20% of midscale. For zeroiDg heter on resislahce

T.a6lers met.! for transistor tesiins.


measuins voliage, drreni, and r$i6tance in a radio under test, tlle VOM can be used to check ihe voltaee of the analyst power supply or drrent supplied to th radio. A 6 inch patch cod is supplid ior .onnectiDg the VOM to the DC OUT for moniloring the current supplied. (Refer io Cureni Measurements in ihe setion titled USING

The VOM h3 four switch positions for measuring volilge, lour for measudng cur, ent, lhree for heasuring resistance, and one for transi6ior testing. In addiiion to



Proteciion for ihe meier moremeDt asainst overloads is built into the instrunnt. The test lead jacks aie spac?d wiih 11 inch.entN to allow the se of the onepiece Gcncral Radio type connector.





auiio s.dion,

Fronr P,nal,



bands of frequencies

Band A 250 KC to 750 KC Band B ?50 KC to 2 MC Band C-10.0 Mc to 11..1 MC Band D 88 MC to 10a MC

AM modulat.d
ANl modulated

AM or FM modulated

INI modulated (70KC



Wiihin 2% at i!55 KC,

KC and all fEquehcies on band D. All other frequencies are within 5% ol indicaied vatue.


Minimum oulpul of 0.025 volts fms onBands A, B, and C. Minimum outDul of 0.010 volis


on Band D.


400 cycle tone. Supplie a midmum of 30% modulaiion and ?0 kc deviation in FM.

in AM

AUDIO OUTPUT: A minimum ol 50 hv rhs at,loo .ycles across a 3 olm load, a minihum 01 1.25 volts at .100 cycles across a 72 ohh load.

sisnal at the AUDIO OUTPUT jacks. The RI bvel variable rsistor contmls the strensih oI ihc RF signal ud ihe AUDIO IEVEL variaue resistor controls the per, centase ot hodulation as well as ihe slrengfh of thc audio sisnal available a1 the AUDIO OUTPUT jacks. The BAND SnLnCTOR swiich and thc EF TUNING conlrol select the dcsird frequency. Sisnal injection i6 the hain use of ihe RF and AUDIO scciion. A known signal is injected into the radio to locate a defectjve stage.

Th. RF and Audio seciion of th. Radio Analysl provides eiiher an unmodulated RI sisnal at lhe RF OUT probe. a hodllated RF signal ai ih. RF OUT probe, or ah audio

Lising the Pouet Suppl-r

thc voliage iequirements of the radio). Soherihes defects are lacated by raising or
lowefng th DC POWER supply vollge which is possible lince 5 smperes is available at all position6 of lhe DC POWER selector swiich.

1. Rotate the poner supply rans. sqit.h 10 ihe desired voliasc. If you are eoing power a car mdio, 6.lcct either the 6 V AUTO of r2 V AUTO posiiion (dependins on

2. Insert a .ed and bla.k alligaior cabl. in each of the DC OUT jacks, color to color. Obsering FroDer polaliiy, c.nnecl the alligator clips to the power inDuts (or oiher test poihis) of the radio under icsteatrem. lisht of ihe fmnt panel. The pilot lamp will light.

!. Apply ihe AC pow.r lo

the Model 970 via iho POWER ON OFE swiich at the

CAUTIONj Do nol short the DC output cables togeiher or you will blow the fuse. 4. To feed a bias voltase into the .irdii urdr tcsr, insed a red allisator cable into the bluc BIAS jack dd rotate thc BIAS control cohpletely count.rclockwise. Comect th alligator clip lo the desired point in th. radio and ldrance the BIAS controt for ihe
The hagniiude of ihc voliases and curenis deiivercd by ihe power and can b monitored b! usins the VOM or tbe 9?0.

bid slpplies

Yoltage Measurements,

1- INert s red ad black aligator cable jn each of t]le VOM jacks, color io color' 2. Rolate the power supply ranse s\titch 1o ur desired voltage. 3. Male thc necessary poner supply connections in a.cordoce wiib the instruciiohs
unde. Power Supply. ,1. CoDn..t the leads lrom the VOM ja.ks io the tcst points in the radio and read thc voltage diFcu)' trom the 2nd or 3d scalc on the meter' If the mt.r rcads down'
scale, reverse the lcads.

5. Monitor BIAS voli:ge by conn.cting the VOM leads bctwcen the bi6 lead and radio chassis grourd. Rotation oI the BIAS .ontrcl will alter ihe voli.ge.

CnrcLt trleasuretnen s:
To hea6ure the iotat currcnt dmwn by a baii.ry powcred radio, perform ile 1, In the interesi of salely, the 9?0 POWIR switch slbuld be OFF 2. Cornect urc 6 inch red paich cbrd belween the red DC OUl' jacL (+) dd the red VoM ja.k (+). 3. Conneci ihe black VOM lead to the Posiiive input ol the radio. 4. Conn cf the black DC OUT ( ) lead lo ure radio chassis ol nesative input. 5. Place th. METER FUNCTION s\titch in the 5A position



tis. s-curenr


eosuemenF, Front Ponsl.

6. Rotate

the pos'er supply ranse s$iich to the approDriaie input voliage ahd appl,\r

?. Read lolal .urr.nt drawn by thc radio directly lmm the correct scalc oD the VON{ meter. If the m.i.r rcads down{cale, relerse th. VOM leads, By applying a 6isna1 to ihe $dio from the sisnal gencEtor of ihe 9?0, the addition,l nnenl draM bv the radio can be m.asurcd at this time.
To measure ihe orreni dEsn from

th. BIAS

supply. perform the followins:


1. ADply po$E to the radio in tle nanner presoibed und.r Power Supplv 2. Rolate ihe METER FUNCTION swilch io ihe appropriatc .uucnt Ense. 3. Conn.t the e inch patch cord belweer ibe bluc BIAS jack and ihc red VOM



.1. Comect the lead from the black VOM jack

(-) to

the poini at which ihe bias

downscale rcverse ihe VOM ]dds.


Read ihe cuuenf direcllv lmm ihe 2nd

o. 3rd

6cale of ihe

meier. If betei


Curred heasurements udthout the power supply: {

If ihe ddio uhder iest is posered by an independent porer supply (batteiy, scn elator, etc.). ihen ihe VOM ol thc 9?0 is used in ih. sme mnner as any othcr VOM.
1. Roiate the METER IUNCTION switch to tne appropiate current raDge. 2. Inse the tea& ftom ihe VOM ja.ks in series sith the circuit beins lesled and lead the currcnt value directly from ihe 2nd or 3rd scale on the mctcr. If thc hctr
Rcsistarce M c6ur enenk I

reads down-scale, reverse ihe leads.

CAUTION: There hust be ho voltase present in the circuit or .omDoncnt lcing
rested when making resistahce heasurements,

t- Rotaie the METER FUNCTION switch io ihe aprrropdaie resistancc mns.. 2. Short the VOM leads logeiher and 'ZERO" the meier rrith the OHMS ADJUST
NOTE: Tl,c metd must be ZEROID" fo. elery resistancc mns.. 3. Separaie the leads and conncct thcm across ihc component of circuit to !e neasurcd. Read the resistance lal e direcily froh the ioD scale of ihc ncter.
Usine t}e low resi6iance ranse, lest capacitor for le"nage or shorts by connecl,ine ihe lesl leads acioss ihe suspecred caracitor. iwhcn icstins .loctmlytics tJe sure io observo polarity. Rcvcrse poladty across an ele.trolviic can destrov the capacito!. The ftd jack on the pmel is posilive iith resDe.t lo ihe black jacl.)

The fmnt to back Diio oi diodes crn also be mensured on ihe Ohmmct.r. The re sistanc. in thc forward direciion should be quiie low while in ihe rcverc. dircction the resisiahce should be quiie high. A froni io back raiio of about 100 to I js .olmon for a good diode. If the resistance of th. diode in both direciions is equal, lhat is very hish or vcrr low, lbcn the diod is defe.i.i\e and should be replaced.

tEt t=t t:tt:tt:lLJ LJ

lEl LJ









Fronr Poiel.

In Cirurit Test-Dyna Trarc: Tlis is perhaps ihe hosi useful test. Since oDlv a sinele probe is ne.ded when tht test is used for signal tracing or, in cirdit tcsting of iransistors, it is a veN rapid method


of locaiine a delective siag. or transistor. To usc this test the radio must be connected to the Analyst power supply dd no1 to m eliernal battery,
Whenever using the Dyna Trace test tuh the volume contrcl on the radio io miniTake i piece of bare coppr wire and w.np it around th. loopstick of the radio and short the ends logether.


The purpose ol thi6 shorted tuD js to load thc mtenm cimuit thereby keeping the radio from Dic}ing up a brcadcast staiion and disiurbins the test. In ihc case of a dead radio this would not be necessary. Perlorm the loltowins steps for In Circuit Tsting:

1. Conn.lthe

power supply of the 970 to the radio in accordacc with the insttuc

tions undcr Power Supply-

2. Rotale the METEIi IUNCTION si'itch i. TRANSISTOR TEST. 3. Set $e OUT'IN CK'f slide swiich io IN CKT. .1. Rotate the COARSE and FINE controls uniil the meid point.r is ai the IN CIRCUIT SET har!. 5. Place th. NPN.I'NI' slide switch in the posilior coftespondine to the Wpe tmn6. lnse th re.l lesl probe in tle rcd jack at the erireme l.ft of the fDnt panel. th. Dfobe to the base of the transisior beins checked. 7. If the meter 6winss up scale, the transisior is sood and can mplify a sighal. It furiher indicatcs thal ihe DC cirditry of ihe stage is sorkins propedy. lf th. meter indicates ro ch.nsc or seinss down-sca]e. reverse the NPN-PNP s$itch. If there i3 still
no indication, the traDsisior o! that portion ol the circuit is ai fault. Repeat lhis tesl on cach transistor in the radio. Each time the Dyna Trece is touched to the base of a tunsisto. the pointer $iU s\rins up scal. and out of the BLUE square, some stagcs will cause the pointer to go ofi scale white othcrs ma,\' just barely move th pointel out ol the BLUE square. As lons as the poiniel moves up scalc this indicaies that the 6iase is operating and that the DC circuitrv is O.K Wheo a 6taee i6 rachcd tbat does not make ihe poinicr read up the meter scate, a defectite stage or tradistor has been locatcd. A fen sidple voliage readinss will qoickly isolate th. dcfect io thc conlohent or to the iransistor itself.

Out ol Ciftuit Test-Ttansistor Tlting:
This test shoutd be Ned to confim whcthcr or not a iraNistor is defective. The test sho!1.I be made wiih tle tran6istor out 01 the circuit. A iest for hoth Lea}ag aDd Beld (Hm) is m.de. The true vahe ot Beta can be read on the 0 300 scale. 'I.hc Leahase test is the I."" tcsi which is the leul,dge bet{eeh lhe coliector and emitter. Hish lealase bciween baia and c.ll.ctor is amplifi.d by lhe transisior and shows up as BAD on the



The Beta tst is a DC tesi wh.re a lixed amount of current is applied to the base of lhe tracistor and the resultani colleclor .lrrcnt lead on the meter. A transistor whosc beta is lcss than 20 is genercllv not considered seful in a radio. Beiween 20 ahd 30 G considered quesiionable. From 30 to 110 is the area inio whi.h nost traNistors will lall and this is considercd a sood transistor. Sincc thc actual Bcta ol transistors found ir poriable radios is rarely knotn, thi6 GOOD (bluc)-bad (rcd) scale will tJe eatler.ly helDful in determining the qualily of a tnsisfo.. As a general nlc deleclive mdio traGistos nsuall,v have high leakage, shofted or open jun.tios. Low beia udis wil noi norhallv result in a dead radio, but misht rcsuli in low sain In hish Beta transistors it is possible ihal the readiDe hay so off or to tull scale and

ihe leakase not be ercessivc. In thai case ch.ck the manufactlreN specincaLioN. leakage is again checled alter thc Beta test allow thc leakase reading to go.lown



To perform Urc OIIT ot.ir.uit tcst. conreci the transistor io the clip leads marhed (ba6.) and C (coit.ctor). U the transistor has sl.itl wirc teads sinpry plug ihe tmnsistor ihlo the socL.t, ,^6 an aid i. i.l.ntilring the emittcr, base, anil collecbr lcads, the more common basiDss for trasistors is shos,n in Fig. 7A. The toca iion of lhe E- B and C 01 the tesl socket ol thc Anahst is shoivn in Fis. ?B.

E (.hil.iet, B

.tif. "1G) r+r4< T-E \r




Tron,isror Bo5hs ConJisurciionr.

7B-Tr.nsnior sockar Conn.di.ns.

can be iested with the 970, The tEtuistor will accomhodate low sisnal tra$bion. Protection is Dlovided lo pielent damase ii ihe trahsistor is inserted impioperly in this
sockel, locaied b$ide the DC OUT jacks,

Both low sisnal

sd poser trtusistors

Power tra6isioN are connccted b!' means of the E, ts, and O lerds beside the rransistor so.ket. Use the larse llue clip lead for the colletor oI porver transistors. .fbe small blue clip l.ad is for te6lina signal transistars,

1. Pla.e the OUl'lN CK'l'slide swit.h in the OUT Dosition. 2. Plac the NPN PNP slide swiich in the appropriaie posiiion. 3. Pla.e ihe POWER-SIGNAI- 6li.le swilch in ihe appropriaie posiiion.
CAUTION: This s$itch must nev.r be in ihe POWER Dositior when a low sighal transistor is beirs test.d. Damase 1,o ihe tEnsistor could easilv result. .1. Pla.e ihe LEAK-BETA slide swit h in the LEAK Dositi.n and read ihe leakage scalc on the meter. lf ihe meter indicates alyNbere in the BAD area. the tealage .urrent i6 l.o ligh and lhe tmnsistor should be replaced.

5. Plac. th swit.h in the BETA position and read the BEI'A scale on th. meter. Il $e met.r iddi.aies anvwhere in th. GOOD area, the b.ta ol tbe transisror is

II there is no deter indi.dlion, revc6. the NPN-PNP swiich and/or check ur. tra.sisior .onnections io the 970. It is not absoluiely necessarv that it be known whether thc transistor is NpN or PNP. By a process of eliminition the iransistor can be tesled wiurout rhis i.torhation.
Let us test an unlnown transistor, Test the tmnsistor with the NPN pNp swirch in the PNI' Dosition and the POWER SIGNAL swiich in the SIGNAI- Dosition. If the tlad6i6ror shoss iow lealage and rads on the B.ta scale the iransistor is sood and is now known io be a PNP. If th. tmnsistor shows no leakase and no Bcia, swjr.h to rhe NPN position. It tbe transistor iests good in this postion, the tEnsistor is now known to be sood and o{ lle NPN va.ieiy. If ihe traNistor tosrs BAD (red) in borh pqqitions ot

the NPN PNP swiirh lhe iransisior is defective and hust be rcplsced *ith the srme or .quivalcnt type- Certain fransisto4, thosc usuauy lound in high frequency ciroiis ol IM sets, ctc., may hav. vcry hish B.tas. U you not. a hish B.ta readins check the

hanutacturer6 srrocification.
The Anal'si
as shortcd or

tuy be used io tesi poser transistors, shich mly b good or bad, such op.n. Power [email protected] arc tGtcd at hish currenis. This G thc 6Ni irue po\rer test alailable in a low co6t iNtrumcni. It can al6o be used to balancc power iransi6io$ ih Dush Dull circuit6.


f;s. 3-audio s.dion, Fronr Pon.r.

Usine Audio Signal lnjection
Sjsnal Injection is lsed ro iest the perlom.nce of 1l\e various stases ol a radio.

In oder io be.ome familiar with audio sieEl inj.tion, Draciice siE:nal inje.iion on a lno$n good radio hd obse e ihe efiect of ihis sisnal- Sigml Injction in trasistor device6 i6 similar io ihat used in vadum tubc cirqits. 1'he sisnal in vacuum tube stases is norhally led into the srid. Ia tr.n6istor6 it i6 eenerally Ied into the base. In ihe lacuum tube circuil the output is Gually from the plaie- In tmnsisto$ ii is usrally from the coucctor. The main difierencc of coursc. is that the vacuum iube is a voltase hplifying derice whilc thc tunsisior is a orrcnt amDlilying device.
To inject a stDighi audio signal inio a radio, connct the leads lrom thc ATIDIO OUTPUT jacls to ihe.iroit beins tsted. Advance the AUDIO LEVEI- control to tbe desired valuc. rt the Rr OUT probe is connecied to the ndio, thc BAND SEI-ECTOR switch should be plac.d in thc RI OFF posilion. ll tho RF OllT.alle is hol conhecled, thc setiing of ur BAND SELECTOR swiich is unimpo ant.

CAUTION: It ibe circuit beins tcstcd by audio 6isnat injeciion has a DC .omponeni V) in 6.ries with tbe red AUDIO OUTPUT lead.
exccss of 400 volts, place a DC blockins capacitor (0.1 mf, 600

The ouiDut level at i.he AUDIO OUPUI jack is adjustable by means ot the contrcl marked AUDIO LEVEL. Wh.n this control is tumed lully counterclockwise to the I{OD OFF position, the audio sisnal is tu.ned ofi. Since th. sam. audio signal that is Ged for audio injection is abo used lor hodulatjon oI the R.F. LI., thi6 is a means ol turning tne hodulation off.

In oder to usc sisnal inj.ction the bla.t lcad lmm the AIIDIO OUTI'U'I jack musi be .onn.ct.d to tbe radio c.mmoD ground. Touch ihe tcst prod to thc hot 6idc of thc Ioudspeaker voice coil.
Thc AUDIO LEVEL control should be ir any posilion oiher than MOD OFF. You lhouid dow hear ihe 100 cycle audio ione in ihe loudsl)e.lthe loudspeaker is oleraiing properly. and so are ihe conta.ts of the earphone plug.

Thc nc:t stase io be testad by sigGl injeci,ion is tbe pu6h pull oulput st.ge. Tou.h the te6r prcd ro The primary ol the push pull driver iranstlrrrer. Adjusl the AUDIO LEVEL conirol tor an audibie sisnal ir i.he loudspeaker. Prcsen.e oI a sisnal indicrtes thsl the outpui stage is capable oI passing an audio signal and would noi be the soume of ituulle if the receiler were dead. Other troubles may however occxr nr rhe ouiDut stase. Distoriion js one sucl trouble.
Now shilt Ure te6t lrod io ihe base oI the audio drive. transislor. The levet of the sisnal heard in the loudspeaker will increase subsianiially [email protected] 10 the added sain pro' vided bv ]!e d.iver staee. The sisnai may be rslored to a lower level by reducins thc AUIIIO I-EVEL.onirol of ihe Analvst. For this and subsequent lests b surc the radn) voluhe .on|rol is !t maximum gain. Any trouble Urat might be present in t!. audio section oI the receiver can asily be isolat d to the sDecific stasc by m.ans ol this sighal

Action of the volume control can bc obsen'cd by injcctinc a sisnal at the output of ih deiccior. AdjrFtneni ot rhe volume control should cause the volume of the signal io cnanse at the loudsDeaker. Another use foi sisml injcction would bc ro checL rhe .ficcri,eness of rhe emiEer bypass capacitor by toxching the test Drobe to the transistor emitter. If the byDass capacitor is opcratins propcrly. ver), liltle sigral will be heard in |he loudspeaker. lf ihe bypas .apacitor is open. the sjgnal heard in the loudspeaker will be quitc ioud, as lou.l as the sisDal woutd !e \rhen ihe probe is b.ought to ure base oi the samc tunsistor.

Ust.g RF S;gzal l4ie.t;on

scal. on th. panel. S.e f.is,

Rf' Signal Injectio. is accomplish.d xsins the calibrated sisnal generator. 'Ihc tuing range of the sen.rator n lrom 250 kc io 108 mc. fou ranges arc .mploy.d nmeiy Bands A, B. C and D. Band A lunes trom 250 kc to 750 k.. 'lhis is th. upp.r

Il' fr.qu.rcy ransc ol an AM radio, ihe two most comrnon on t|e dial. These points are 262 kc and 455 kc. Band B tunes lroh ?50 k. io 2000 kc, or 2.0 mc. fhis range wonld be used most comorrly for siqnal injection into RF stases. Band (l tnn.s lrom l0 hc to 11.1 mc in two positions, Il' fr.qx.ncies are marked
Sin e Band A coveN the Sisnal Injection (IF) in FM radios, 10.7 mc is mark.d on Eand C. Band D lmh 88 h. to 108 m.. 'lhe RF signal g.rcrator .an be turned OFF. or BAND A, BAND B, BAND C, ol BAND D cnn be sele.ied tv means of the BAND SELECI'OR swiich. This swiich c located jusi lbore the RF LIVEL coniroL and is shoirn in ris. 4. The .utpui lroh ihe slsnat generator is iaken irom th. RF OUT prole. Se. lig. 4. No sfuund connection io th (--) minus VOM jack is n.c.ssarr and sh.uld not b. used.




Connect ihe black probe oI R.F. OUT cable to chas6is and th. red probe to the point of sisml injeclion. The RF level control for the sienal generator is located to the dsht of

The RF oscillaior i6 AII modulated with a 400 cycle audio tone in BANDS A, B and C (AM) md I'M modulated (70 KC devjation) in BANDS C (EM) and BAND D-

To supply an unmodulatcd


sisnal to a radio, peform the following:

1. Connci lhe RI OUT probe to the rdio circuit in question. 2. Rotate ihe BAND SELECTOR and RF TUNING dials to the desiled fr.quency. 3. Adjusi the RF LEVEL conirol for th. desired sisnal sirensth. 4. Tum the AUDIO LEVEI- conirol io the MOD OFF position. To supply a modulai.d RF signal to a mdio. perfom the fiist three steps listed above, ihen rotate thc AIIDIO LEVEL control to ihc d.sired percentage of modulation!-or normal RF and IF sisnal injeciion ihe hodulation would be lelt on. In thc cvcnt
ihat ihc local oscillaior of ure receiver is to be replaced wiih ihe hodulaiion sould bc tnmcd ofi.

ilt sisml

from the Analyst,

Placticc signal inje.tion on a knorrn sood AM mdio io becohe fahiliar with this te.hnique. The BAND SELECTOR swikh is set io BAND A. The pointer on the tunins dial is set so that ihe hairline on th. plastic pointer is on 455 kc since ihG is the L!'. frequency of urc radio wc are tlinc. Before sielll injeciion the dio nusl- he di6abled by wrappins a sinele 6horted turn oI wi.e aroud ih loopsiick antnna. This will preveht the mdio froh picking up any broadcast statiohs that would produc. faulty indications. The BAND SELEC1OR switch should be in the Band A posiiion dd the R.FTUNING set to,155 on ihe A diai. Touch rhc red RF OltT proh. to the input ot thc detetor stage. Io. injeci.ion at ihis point the level control6 would norhally le set to maximum. The 400 cycle test tone will Dow be head in ihe loudspeaker. Il the sound lails to appear in the loudspeaker be $re lo adva!.e ihe volume conirol uniil the sound

volme conirol appeals betw..n the source ol sisnal and the loudspeaker. control the amouni of sound heard in the loudspeakei. We wodld not norhally expect the intensity of lhc tst tone in ihe loudspaker to be very lond sinc. thcro is litile amllilicalion beins prolided for i]lc siflal.

jt will

Since the

Mov. thc tcsi Drod frod lhe deiector inpul and tou.h ii 10 the input of the last LFtransfomr. If the signsl is aeain head in ihe loudspeaker Fe have rJroved thai the transtomer is opcrating. If the Sigml Genemlor frequcncy is chanscd thc sisnal will set \reaker as it i6 dtuned lrom the proper LF. frequncy. R.set the ceneEior back to 455 kc. Shift the RF OUT p.od ftum the LF- translormer to tle input of the lst stase of the LF- mplification. We ar. now feedins tbe sis.al into th base of the LF. ampliffer. Since tbe sisnal is now |eihs ahplified by the LF. ampLificr, the levet of ihe signal heard in the loudspeaker will increase substantially. Reduc. the level control on the Analyst to.ompensate for this increa6. in sain. Always \'oik sith the minimrm mount ol sisnal in order to prevcnt ovelload of the implifier
slaces in ihe receiver.

We have now demon6iraied ihat fiom the bnse of ihe lasi LF- adplifr to the loud.tdio is operating rrroperlv. Shift the test prod to the input of th. n.lt I.F. ampliff.r- With doiher stage of sain presenl, ihe sienal shoxld asain incr.ase in level at the loud6peakel Again }educe the lvcl control of the Analyst to compeNate for this increase in gain. [email protected] ihe sisnal .an be heard wher injecied inio the b8e of th LF. amplifir t.aNistor, we havc dmonsirated that the LF. systam and audio system are
sDeaker, the

The inpui of tbc convelter js ihe next point lor sieDal injection. Thi6 is ihe base of the .oDverier lransistoi. Althoush some LF. sisnal will set ihtuush, the siBral at this Foint is in the R.F- range and the sisnal Genedtor musl be reiuned io an R.E. frequncy. Lt us use 1.0 mc. FDr thtu frequency tbc BAND SEI-ECTOR switch mwi b set io Band B and the R.F. TUNING dial set to r.0 nc (1000 kc). The radio musl also be luned io 1 mc. Touch the test prod to the base of ure con!rter tmnsistor. The sisnal should now be hard in ihe loudspcak r at full volum. since all ot the sain of the radio is now in use, The os.ilator section mry be iesid by measuring the base io cmiitcr voltasc. Thi6 voltasc should chang. 6lishtly as ihe variable tuning capaciloi is rotated through its
I-oose-couple the ANALYST to ihe oscillator coil or ihc input convortel. Sei ihe R.F.

Anolher tchnique for

tsiing tle

osciltaior is to tune the mdio to a

ln.wn station.

thc sei.


ro lhi r.n$r lrquir.\ tlL. rlF T.f lrrqLFn,j ^l the 6tation can bc h.ard, th.n the oscillator ot the sel i6 defeclive. This Darapproach uses ihe ANALYST as a replacemeht oscillaior-


R-F. Si$al Injection in an liM radio i6 accompli6lrcd br, lsins Band! C and D. For R.F. Sisnal Injection ot I.F. frequencies, use Band C, and position thc RIr TUNING conirol lo the 10.7 hark on the diat- Sef the BAND SEI-ECI'OR ssiich io ihe 10.7 r'M

SELECTOR seiich to Band

For sisnal inje.tion of R.F. IM lrequencies, use Bald D, and set urc BAND D (88 108 MC). Po6iiion the R.F. TUNING control nr tbe





' t'


*-" {"-.





Es. 9-rypi.ot Rorio Derodor cn.un.

Aligning a Ratio Detector
VarialioB of
applied from the 6ienal senerator lo the .ircuit obse.ved on ihe VOM while tunins.

tuins is chascd is the basis lor ihis

d-c loltage ihat take plac in difierent parG of fhe receiver ci.cuit when

Dethod of alienmenl.


test, md changeB in voliase are

A sieadv cadcr


For alisrDni of the miio detcctor, use the VOM and Sisnal Genrator of the Radio Analyst. Connect ihe R.F. OtlT probe to the b.se of the last I.l'. amDlifier trdsistor. Turn the BAND SELECTOR switch to the 10.7 IM C posiiion and rotate the R.I.. TUNING coni.ol io the 10.? MC mark- Cohhe.i the VOM aooss resisiors R5 and R6 of fiElre 9- Adjusi the primary of tbe trdslormer for maximm deflc.,iion of the merer. This shows tbat haximnm curr.nt i6 dowins th.ough lhe lord rcsistors (R1 and R2) and

To align the secondary ol the transfoner. connect the VONI across C6 and iune foi dcflection iowards zero or ihe VOM. This shows ihat the secondarr is exactly centered in the I F pass band.




I.F. Stagea

fhe lliermeni of the I.F. stases in a rcceiler .oNists of measurins the loltage devel oD.d at th. delector circuii as ihe LF. amDlifiers are tuned. In ihe Elio detector. conn.ct the meter across thc load capiciior and connect tle signal g.ncrator to the input of the first LI- ahplifier Startins wiih ihe lasl lF., lune each I.I'- tor naximum deection of the
conneci: a low value resistor (200 to 500 olhs) with short 1.ad6 across the secondary ol the overcouDled transrormer. This rcduces ihe Q oI the translomer. Thc reduced Q sup'

mcio. Ir any of ihe LL ahplifie6 is ov.rcoupled, (i\ro

maximum deflections)

Dr.sses ihe double huhp.d charactristic of the overcoupled circuit rcsultins in a sinsle broad pcak. ObseNe the outDut met.rr carelutlv tune to the exact cenler ot tnis D.ak. Discon.cct the loadine resislo! when the srasc has been alisned.

Aliettment ol R.1., Miret, atd Os.illdot Thc aligmeni of R.F. aDd Dia.r 6tases rcqdre the adjusimeni of irimmer capacitors to ffequ.ncics in the low, high, and centFr portions ol thc rcccilcr dnge. The diaer
and lhe oscillator must track oler the desired ranse as ihe r.ceivcr is tuned. The mixer and tne oscillator timmeN are adjusted at the high frequency ehd oI the dd ihe osciuaior pad.lr is adjusted at the ]ow. Set the F.M. receiver tunirLe control to 106 mc. Connecl the R.I. t.ncrator to the antenna temindl. Set its frcquency to 106 nc and AUDIO LEVEL io \'IOD OFF. Vary the os.illator lrimmcr until th. signal is heard in the outpnt ciruit, or until the meir in the deteciion circuit

iunins ransc

nrdi.ales naximuD defleciion. Peak ihe mif,.r srid-circuit trimmcr lbr mimlm output. Ttne the FM recivcr to 90 n.. and iune the signal generaior io 90 hc, Adjust ihe os.illator padder uniil ih.6isnal is marimlm at the deteclor.

Check tl[ rcsDonse at 106 m. and leaajtst the oscillator trimmcr. il ncccssary, to ma}e the dial calibration of the recejver cor.esDond to Ure llequenq' ot the sen.rator. Rcp.at ihese steps until |oth th. lo$ an.l the high frequen.ies are on calibmtion. Sei ihe sisnal senerator lo a point midFay nr $. lrequen v rance, and check the calibra' tion. Wlen thesc stelN have been carried odt car.tully, urc calibration should }e con.ct-

To alisn ihe R.F. siage, ahicnna nois. or a weah exteDal sisnal supplicd by lhe lcakage from Ure sisnal scnerator or ahy other source, such as a fluorescehi labp, ele.iric

shav.r or a miaer will do lor the 6rst rcush initial alisment- Pesk ihe idmer for haximum sisnal al lle hish nd of thc lrcquncy range, and apply the noise gneraior technique at the highesl lreque.cy to obtain ihe maimum sisnal-to-noisa mtio.

Pedorh th. .quivalent of plotting.n s cuN. to chch ihc alisnment ol latio detector. lrse thc Analwsi Sicnal Gencrator and VOM. Ihseri a I0.? umodulaied sisMt into ihe re.eiver and comect ihe vOM across th. ouipui of ihe mtio detector. Thc VOM shoxld rcad zero. In.rease thc signai generaior trequeDcy by rotatins ihe FINE control on the R F.'ll \l\C .o.,'ol cl".L$ie . \uri,- lhel irr' .o"8ga r,adi.; r,1a.^q wrl' rrr' ilcrease ol lrequencv. When the matimum loltase point i6 found, record the voltage and record the fr.quen v indicaied by tle R.F. TIINING dial.
de.reasc the frcquency and record the frquency at which the meier asain indicaics a haximum loltage readins. Rccord this voltage. The iwo loltage p.alis 6hould be equal in dplilude and occur at the sahe distancc fron thc center tuequency.

R.tum the R.]r. TIINING conirol io the cenler frequency. From tiir null point.

The bandw th drle ot ihe I.I. ampliliers can bc found br. the same method s was ns.d to 6nd ihe S drve of the ratio detector. Connect the VO\'l lo the output of ihe lasl Lf . mplifier and ins.rt a 10.7 udodulaled siCnal.

Oberve ihat meler js readirg at a null Doini. Increasc the trequenc, ol the R.F. TUNING coni.ol slowly and notice thal the heter indication in reases slishily and thcn drops ofl shalp]y. 1'his is the upper limit ol ihe band$idth- Re.od th. \'ottage and Jrcquency at which tha pcak wa6 reached and dlso record thc trequcncy ai whi.h ih voltase dropped suddenlr'. The lower limit is found in the same way ex.ept that lhc trequency of the RF TUNING control is decr.ascd slowl\,. The sum or these two Irequency deviations is the LF. bandwidth.

Th analrs! 6chemaii. will aid you in trouble shootins the Rsdio Analyst. The mp line fuse ad a 5 amp power sulply fNe. which are lo.aied on ihe .ear apron ol ihe chssis, Replacement mu6l be made with idcntical types in
instrument .onlains a 3

order to reiain protection oi thc











v;6w of chdssis Apron shovins Tw6

snd 4 DioJ.s.

Trasisiors arc locatcd above the chrssis and are accessible when ihe chassis is rcmovad from tne cabinet. The powci irasisio! is nounted on the chssis. The oiher Transistors are mounted on the printed cjrcuit board above the BAND SELDCTOR

'lo remova i"he chassis lrom lhe cabinel, remove the four icrews on ihe bottom of thc .abinet nrt to the rublier feet and skle chassis forward and oui of .abhet.
U R.F. alicnment of thc ANALYST is needed an AM radio r.caiver nar be used


1. Turn AUDIO LEVEL knob io MOD OFF (turimm colnierclockwise rotaiion











tuned cdk, c4, wcfer swit.h cid ourliie 6l Iunins Ccpc.iroi

2. Place the RF. OUT

Drobe of thc Analysl close

to the antehDa ieminal of the

zero bears wiih ihe siation. If ihe relding on Bahd B is noi the same ftequency ds Urc staiion, set th R.F- TUNING lnob to the lrequency of the siation. If the R.F.


3. SFii.h ihe R.F. BAND SELECTOR sFitch to Band B 750-2000 KC. i|- Tune ihe re.eiver io a station aronnd 850 kc. 5. Startins at 800 lc rotaie the R.F- TUNING control until the sirral from ihe

TUNING tnob orisinally read hiehe. than the station frequency (when zero beai was heard) the iron coE of coil L-2 should be rotated out of the coil slishtlv hiil anourr zerD beat is heard. If the iunins knob orisnraly read lower ihan the station frequency. th iron cor should be rotated clockwise into the coil. Use a non metallic h.r head
Urc samc freqnncy as thc sialion. Adjust ihe

6. Tune the rceiver to a station aroud


kc. Set the R.F. TUNING knob io iimmcr on thc small lariahle .apa.ito}


Rcpcat sips


ihroush 6 until no turther adjustnent is neded.

When Band A alisment is hecessarv proceed as folows:

SELECTOR switch is ss'itched to Band

1, R.peat Steps 1,2,3 and 4 of R.F. alism.nt.rcept ilat the R.F. BAND A 250 750 KC and a station tued betwecn

2. Adjusr itr RF l.uNrNG knob ro the sme frequency as itre sratjoh. 3. Adjust ihe froht lrimmei (on ihe valiable capacitor closest to ihe panel) Ior


4. Wilhort changins the tunins of the radio re.eiver, roiste thc RF TUNING knob to % th. fr.q!enc,\. ol the siation. Adjust th powdered iron core on.oil L,3 lntil a

il until no further adjustheni is needed. For Band C and D. an FM radio Fceiv.r nay bc used as follows: 1. ReFaN Steps 1,2, 3 md i! of R.F. alisrment, ex.ept thai U,e BAND SDI-ECTOR is swii.hed io Band D 88-108 \IC and a station sele.id belween 9a-108 m.. 2. Adjusi R.F. TUNI^_G knob to the same lrequency as ihc station.
2 ihrough

5. liepeat st.ps

l() % the frquency oI the 6tation. Adjusi thc brass slus in coil L-4 until a z.ro bcat is heald on thc rcceiver-

3. Adjust irimmer .apacitor C.1 (mountcd on coil Il) 1or a zero bcat. 4. Wilhout.hansi.g the tunins ol ihe mdb receiver. rctrre the R.Ir. TUN1NG 5.
Repeal sicps 2 ihrcush i! uDiil no luriher adjustmenl is needed.


Whcn Band C aljgnnent is necessary, proc..d as lollows:

1. Repeat sieps l, 2 and 3 of R.F. aliglmenl ex.epi ihat thc F.F. BAND SELECTOR is switched io BaDd C 10.7 MC FM. 2- Selct an FNt stati.n in the 100 io 104 NIC lanse snd set the R.F. TUNING control to one.tenih oI the frequenc! ot the radio 6tation. Foi example, if the staiion 6e]ecled is 10t MC sei ihe R F. TUNING .ontrol ro 10.? mc on lhe dial. A.ljust powd.r pi\-'. :rcn r^-e in l. I rn., -."oba'.-h.rrJin,L..




Refer to the maintenance section ol the instruction manual lor adjust' ments that may be applicable. Check common electronic parts such as tubes, transistors, and batteries. Always check instruction manual for applicable adjustments alter such Delective parts rcmovcd from unih which are within the wauanty period should be sent to ihc factory prepa $'ith model and se al number of instrument lrom which rmoved and date oI instrument purchsse. These pa|r" s.Jl Lc e'.han;ed ar nn.harsc lf the above mntioned procedurcs do not couct tbc difliculty, pack the instrument securely (preferabl] double packed). A detailed list (r1 troubles encountered must he enclosed as \\cll as your name and addressFolward prepaid (express prelrred) to 1.he neafest B & K autho zed sewice agency.


nearest serYice agency, or B

Cortact your local B & K Distributor 1or the name and locatjon of your



Serxi.:e De?art,nent




l80l S.

Bellc Plaine





.iB &

x ru/uh

rhrt sch plo


our obltstion under


nelf, d'Ys

aitcr s Puchase


wmntt is ..dBiE ond in li.u al dL other uananri$ (indu'ti4 ant tutrntt ol herhanhbnn!), uh4rh.t dpres' ot inpLi.tt. such wlrmry sholr not apply conporan (j) rpailed or dbEd by alyone olhd th& ts & K o (exepi nomd iube repl&cbcni) [email protected] & Kt prjor *riibn apprcvsl Oi) lartleied wnb or dbEd iD lby uay or sbjatd io nisE, nlisence or aco&nl (in) whjch L the snar '@be. altEd, dcrded o. Ifrovedi or (iv) vhich has ben iDproFdy co.n&1ed, iDsbne.l or .djusied
The latesoinE

DthsNie than in leodaDco wi

6briart:6. The uddntt shalt be Daid .nd 1t2.e rhrll be no uatuntt ol ot! Pnaur .r 6n @nenrilaB&KuardnttE! B & K [email protected] uithin tue datr altet the purchBe o1 the prcd'ct tub l-tm an outhotaed


,( taANUFAcTuBtN(i cotlt PANY Drvrlrox or co*PorarroN

Copyr'Eht @1965