C O P Y r O F 5 0 0

L 1 2 7

OPERATING AND MAINTENANCE MANUAL

F O R

T R A N S M I T T E R S T- 2 A

T A B L E O F C O N T E N T S

PageS e c t i o n

1 . I N T R O D U C T I O N

1 - 2Scope1 . 1

1 - 2G e n e r a l D e s c r i p t i o n1 . 2

1 - 2G e n e r a l S p e c i fi c a t i o n s1 . 5

1 - 31 . 4 A u x i l i a r y E q u i p m e n t

2 . P R I N C I P L E S O F O P E R AT I O N

2 - 1G e n e r a l2 . 1

2 - 1D e t a i l e d D e s c r i p t i o n

a.' Audio Amplifier and Modulator Circuit

b . O s c i l l a t o r a n d A c i p l i fi e r - D o u b l e r C i r c u i t

2 . 2

2 - 1

2 - 1

2 - 2c . P o w e r S u p p l y

3 . OPERATION

3 - 1G e n e r a l5 . 1

5 - 1O p e r a t i o n5 . 2

5 - 1I d e n t i fi c a t i o n o f T u n i n g R a n g ea .

5 - 1b . I d e n t i fi c a t i o n o f A d j u s t m e n t s

5 - 1Set t ing the Pr imary Vo l tagec .

5 - 2d . O s c i l l a t o r T u n i n g

5 - 5e . F r e q u e n c y C h e c k

3 - 4f . A m p l i fi e r - D o u b l e r T u n i n g

4 . M A I N T E N A N C E

4 - 14 . 1 G e n e r a l

4 - 14 . 2 Te s t E q u i p m e n t

4 - 1a . R e q u i r e d

4 - 1b . O p t i o n a l

P a g eS e c t i o n

k - 1G e n e r a l P r e c a u t i o n sh . 3k - 2Sectionalizing and Localizing aPaiolt4 . U

k - 2T r o u b l e s h o o t i n g C a i a r t4 . 5

4 -5Vo l tage-Res is tance Char t4 . 6

5 - 15. PARTS LIST

LIST OF ILLUSTRATIONS

P a g eF i g u r e H o .

1 - 1Photograph -Transmitter ST-2A

Power Transformer Wiring Diagram

A.F. Board Assy -Component Layout and Test Points

R.F. Board Assy -Component Layout and Test Points

High Voltage Board Assy -Component Layout andT e s t P o i n t s

Low Voltage Board Assy -Component Layout andT e s t P o i n t s

1 - 1

5 - 25 - 1

4 -74 - 1

k - Q4 - 2

4 -5 4-9

4 - 44 - 1 0

4 - 11S c h e m a t i c D i a g r a m4-54 - 1 2I n t e r c o n n e c t i o n D i a g r a m4 - 6

M i c r o p h o n e a n d C a b l e '

«

S T - 2 A

1 . H y E R O D U C T I O N

1 . 1 S C O P E

This instruction nmniift i contains information for the installation, operation,and maintenance of the transmitter. Model ST-2A. ®he equipment is ^wn inF igure 1 -1 .

1 . 2 G E K E R A L D E S C R I P T I O N

Biis PM trans- "The transmitter ST-2A is an improved model of the ST-2,mltter is intended primarily for surveillance applications where it is desired

T r a n s i s t o r s a n dt o t r a n s m i t i n f o r m a t i o n t o a r e m o t e p o i n t f o r m o n i t o r i a g .suhminiature components have been used wherever possible, to minimize size andreduce power consumption. Within the limiiations of the size requirements, the\inlt has been designed to provide reliable, unattended operation under adversec o n d i t i o n s .

1.5 CaSKBRAL SPECIFICATIONS

Tunable over aminimum range of 6bicbetween 56mc to 8limc

F r e q u e n c y

Frequency modulat ion

Adjustable from 5kc to 50kc/l00(jivoltsi n p u t s i g n a l

50 mwatts minimum (into 50 ohm load)

115V or 230V, 50-60 cps.

1.5 va at 190 vac, 2.0 va at 2J0 vac,2 . 5 v a a t 2 5 0 v a c

not more than 6db down at 400 ops. and5500 cps when referred to oui^ut at1000 cps

Shure MC-11 or an equivalent 1000 ohmr e l u c t s j a c e m i c r o p h o n e

40" length of Aniphenol Ho. 14-500 cable

55 /8 " X5" X11 /4 "

1 9 o z .

M o d u l a t i o n

D e v i a t i o n S e n s i t i v i t y

Power 0u l5 )u t

I n p u t v o l t a g e s

Input power (volt-amperes)

Aud io F requency Response

M i c r o p h o n e

A n t e n n a

D i m e n s i o n s

W e i j ^ t

1 - 2L12T

S T - 2 A

1.4 EQUIPMENT LIST

a . E q u i p m e n t s h i p p e d :

The unit is shipped contBlete with -

T r a n s m i t t e r u n i t

A n t e n n a

M i c r o p h o n e a n d c o n n e c t i n g c a b l e

T u n i n g t o o l .

h . A u x i l i a r y E q u i p m e n t

An PM receiver (tunable from 56mc to 84mc) is required for use witht h e t r a n s m i t t e r S T - 2 A .

L 1 2 7 1 - 5

S T - 2 A

2 , P R I K C I P L E S O F O P E R AT I O N

2 o l O E H E R A L

'T'hta eoniplete transnitter (ST-2A) circuit is shews, in Figure B i e c i r ¬c u i t c o n s i s t s o f a t u n e d p l a t e o s c i l l a t o r , a f r e q u e n c y d o u b l e r , a t h r e e s t a g eaudio aaplifier, and associated built-in power supplies» Two subodniaturevacuum tubes are tised in the r.f» section, while the audio circuitry employsthree junction transistors. Transistors have been used in the audio sectionto achieve minimum power dissipation, :6educe size, and insure maxiisum relia¬b i l i t y .

2 . 2 D E T / L I L E D D E S C R I P T I O H

a . A u d i o A a p l l fi e r a n d M o d u l a t o r C i r c u i t

T r a n s i s t o r Q 1 i s t h e fi r s t a u d i o a i ^ l i fi e r s t a g e , u t i l i z i n g a l o w - n o i s ePUP transistor (Philco 2N207B) in the coassHon emitter configxiration. The outputof the microphone is coupled to the base of Q1 by C9« R5 f o r m a v o l t a g edivider network to provide base bias for Ql. 'Hie combination of R5, R8 and theemitter resistor R12 provides teng^rature stable d.e. bias for Ql. C15 <tucL C20a r e r. f . b y p a s s c a p a c i t o r s ,c o l l e c t o r l o a d r e s i s t o r .

R l l i s t h eC12 is the emi t ter bypass capac i tor.The output of Ql is coupled to Q2 by GIO.

Transistor Q2 is the second aMio amplifier stage, uti l izing alow-noisePKP transistor (Philco 2N207B) in the coaamon emitter configuration. r8, r6, andR26 form avoltage divider network to provide base bias for Q2. R6 is ad.so theDeviation Sensitivity Adjustment for the \mit. Hie combination of r8, R6, R26,

the emitter resistor Rl^i- provide tea^erature stable d.c. bias for the stage.R I 5 i s t h e c o l l e c t o r l o a d r e s i s t o r ,t h e e m i t t e r b y p a s s c a p a c i t o r .

Transistor Q5 is the third audio aa^l ifier. 'Di is stage also ut i l izesalow-noise PKP transistor (Philco 2K207B) in the coamon emitter configuration.R7 *r>(^ RIO form avoltage divider network to provide base bias for Q3« Thisstage differs from the first two audio stages in that the base bias resistorRIO is returned to the collector of Q5 rather than B-, in order to iaprove thestability of the circuit. R7, RIO, RI5, and the emitter resistor RI6, providetea^ je ra tu re s tab le d . c . b ias fo r t he s tage ,r e s i s t o r . C I 7 i s a n r . f . b y p a s s c a p a c i t o r .The output of the audio section is cor^led to the grid of the oscillator (Vl)b y C 7 .

C l 6 i s a n r . f . b y p a s s c a p a c i t o r . C I 3 i sThe output of Q2 is coupled to Q3 hy CU.

R I 5 i s a l s o t h e c o l l e c t o r l o a dd k i s a n e m i t t e r b y p a s s c a p a c i t o r .

b . O s c i l l a t o r a n d A B ^ l i fi e r - D O u b l e r C i r c u i t

V I i s t h e r . f . o s c i l l a t o r t u b e . O s c i l l a t o r f e e d b a c k i s a e c o n 5 ) l i 8 h e dthrough the secondary of T-2. R^i- is agrid leak resistor for VI. C6 is agrid leak bypass capacitor for Rl^. R2 is ascreen grid dropping resistor and

2 - 1L I 2 7

S T - 2 A

C3 tlie screen grid "bypass capacitor for Vlo C4 is afilsaaent "bypass capacitor.C8 is an r.f. bypass capacitor.

V2 is the r. f . aaipl ifier doubler tube. R3 is agrid leak bias resistorfo r V2 . R1 i s asc reen g r id d ropp ing res i s to r, bypassed by G2 .ment bypass capacitor, fflae output of 'the transnsitter is transfoimer coupled tot h e a n t e n n a b y 5 3 .

d i s a fi l a -

P o w e r S u p p l yc *

The transmitter may be operated on 1152 3 O v a c , d e p e n d i n g o nwhether the two primary power tiansformer windings ax*e in series or in parallel.T3ie power transformer (EL) has three secondary windings each feeding into aseparate rectifier circuit, one providing transistor voltage, one tube platev o l t a g e , t h e o t h e r fi l a m e n t v o l t a g e .

1 . F i l a m e n t S u p p l y

Terminals No. 8and No. 10, eentertapped at tenuioal No. 9, stj^plyeight vo3.ts ac at 100 ma. This is full wave rectified by diodes

and D5. R23 and R25 are used to st^press switching transientsin the diodes. 0u1p)ut ripple is reduced to svifficlently low levelsby the R-G filtef.section, consisting of C22 and C23 in conjunctionwith R25. The dc drep in R25 sets the correct voltage (2.5"vfor the filaments of tubes VI and V2. (Each filament has a1.25Vdrop to ground.)

2 . P l a t e S u p p l y

Otermlnals No. 5and No. centeitapped at terminal No. 6, stpply65 volts ac at 6ma, each side of ceaterbap. Bie full wave recti¬fier cons is ts o f d iodes D1 and D2 and t rans ien t suppressor res is to rs ,RI7 and R20. The R-G filter section consists of RI8 and RI9 inconjunction with the three section electrolytic capacitor, Cl8,a,b,c.Approximately 65 volts dc is supplied to the plates of VI and V2.The screen grids are also supplied by this section through droppingr e s i s t o r s R 1 a n d R 2 .

3 . T r a n s i s t o r S u p p l y

Oferminals No. 11 and No. 12 supply 7v at 2ma necessair for theaud io sec t i on . D3 ha l f wave rec t i fies t he Jv ac supp l i ed byR21 in conjxmction with 010 and C20 provide the first section offi l t e r i n g . R 2 2 a n d C 2 1 p r o v i d e a d d i t i o n a l fi l t e r i n g .

Ifeder normal qpeia,ting conditions, 6v de is available for Q2 andQ3» Both lower voltage and additional filtering are necessary fort r a n s i s t o r Q l .

Uhder normal operat ing condit ions, dc i® avai lable for t ransistorsQ2 and Q3. Both the lower vo l tage and add i t iona l fi l te r ing are neces¬sary for Ql. This voltage is minus (-) 3vdc normal.

2 - 21 1 2 7

AMEnSDMENT NO. 1

Sec t i on 5 .2 .a I den t i fica t i on o f Tun ing Bange shou ld read :

Each uni t is shipped f rom the factory pre-tuned on one of three centerfrequencies. One corner of the transmitter case is colored in order to identifyi t s f requency range , as fo l l ows :

T u n i n g R a n g e

+ 4 k c+ i ) - k c+ 4 k c

C e n t e r F r e q u e n c yC o l o r

59 me68 me77 me

G r e e nB l u eW h i t e

S T “ 2 A

O P E R A T I O N

5.1 GrENERAL

Since the t ransmi t ter ST-2A is des igned to operate cont inuous ly and wi thoutattention (whenever proper ac line voltage is applied to the unit), this sectionwi l l he concerned main ly wi th prepar ing the uni t for use. This may best be ac¬c o m p l i s h e d i n a l a b o r a t o r y , p r i o r t o fi n a l i n s t a l l a t i o n .

5 ,2 OPERATION

a . I d e n t i fi c a t i o n o f T u n i n g R a n g e

Each uni t is shipped from th.e factoiy pre-tuned on one of three centerfrequencies. Adot of paint on the transmitter ease identifies its frequency range,a s f o l l o w s :

T u n i n g R a n g eC e n t e r f r e q u e n c yC o l o r

+ 4 k c+ 4 k c+ 4 k c

60 me70 me80 me

G r e e n

B l u eW h i t e

b . Ident ificat ion of Adjustments (F igure 3- l )

There are two timing adjustmeats and adeviation sensitivity adjustmentin the tiransmitter, as outlined below: T h e y a r e n o t c o l o r c o d e d .

R e f . S y m b o lL o c a t i o nN a m e

T h e r e a r e t w o a c c e s s h o l e so n t h e s i d e ® f t h e t r a n s ¬

m i t t e r . T h e a d j u s t m e n t n e a r e rt h e u n i t c o v e r i s t h e O s e .Tuning Adjustment ,

T - 2O s c . T u n i n g A d j .

T h e a c c e s s h o l e b e l o w t h e O s c .Tun ing Ad j . i s fo r Ton ing theA m p . D o u b l e r .

T - 5A u r p - D o u b . Tu n i n g A d j .

R - 6T h i s i s l o c a t e d w i t h i n t h et r a n s m i t t e r i n t h e c e n t e rof the audio board, and isi m m e d i a t e l y a c c e s s i b l e a f t e rt h e t r a n s m i t t e r c o v e r h a sb e e n r e m o v e d .

D e v i a t i o n S e n s i t i v i t yA d j u s t m e n t

c . S e t t i n g t h e P r i m a r y V o l t a g e

D e t e r m i n e w h e t h e r t h e t r a n s m i t t e r w i l l b e o p e r a t e d o n I I 5 v a c o r 2 5 OTo se t t he p rope r p r ima ry vo l t age f o r t he t r ansm i t t e r, t he f o l l ow ingv a c .

p r o c e d u r e i s r e c o m m e n d e d ;

1. Remove the two (2) 4-40 x3/I6 B.H.M.S. from both ends of thet r a n s m i t t e r c o v e r a n d l i f t t h e c o v e r o f f .

5 - 1L12T

S T - 2 A

2. I t w i l l be noted that each wi re f ro ia t ransformer T~1 has anidentification tag attached to it^ By viewing Figure 3“1 orFigure h-'^, it can be determined whether the transformer isw i r e d f o r t h e c o r r e c t v o l t a g e o

^ ^ ^3. If achange in wiring is neeessaxy, I'ecoxjnect wires 1, 2, 3> ahd

in the desired configuration, as sho^ru in Figure 3-1 (below) orF i g u r e

!»●. Place insulating tape over each solder Joint to prevent anys h o r t i n g .

2 3 0 v a c11 5 v a c

O 1

0 2■0211 5 v a c230 vac

* - 0 4L 0 4

OO 5

WIRING DTAGR.^14 mR PEB^ARY OF T-1F i g u r e 3 - IC A i i n o w

Make sure the proper wires are soldered to¬gether, since solderirtg iiie wrong primarywires together may cause either the primarytransformer windings or -fi ie r. f . vacuum tubest o b u m o u t .

d . O s c i l l a t o r T u n i n g

The osc i l l a to r tuned c i r cu i t shou ld be se t to the des i red f requency.(The oscillator can be tuned +4mc in the 28 to 44mc range.) 'Ihe procediurefor sett ing the oscil lator frequency is as fol lows;

1. Remove the access plate located on the side of the transmittercase. F igure 1-1 .

2. Locate the oscil lator Tuning MJustmentj it is the adjustmentc l o s e s t t o t h e t r a n s m i t t e r c o v e r .

Startirig with the slug in its couircer-clockwise extremity (thehipest frequency is obtained witli the slug in this position)rotate the slug clockwise unt;ll -the desii-ed frequency is ob¬ta ined . I t i s no t recommended to con t i nue c lockw ise ro ta t i onfurther than the point where the frequency s'barts to increase.

3 .

3 - 2L I 2 7

S T - 2 A

N O T E

C a r e m u s t b e t a k e n n o t t o r o t e t e t h e s l u g t o o f a ri n t h e c l o c k w i s e d i r e c t i o n s i n c e t h e t u n i n g t o o lmay become disengaged from the flats on the slugs h a f t . I f t h i s o e e u r s , i t i s n e c e s s a r y t o r e m o v et h e t r a n s m i t t e r c o v e r ^ p u l l o u t t h e r. f . c h a s s i sand turn the core back into the coi l form^, fromt h e o p p o s i t e s i d e .

e . F r e q u e n c y C h e c k

The osc i l l a to r f requency i s exac t l y one ha l f o f the t ransmi t ted f requen¬cy. The following two methods may be used to determine whether the transmitteris operating at the desired^frequency.

M e t h o d N o . 1

C o n n e c tAttach the microphone and antenna to the unit ,t he power co i ^ t o a . c . l i ne .

Operate the unit in the vicinity of areceiver^ tuned tot h e d e s i r e d f r e q u e n c y .

1 .

2 .

R o t a t e t h e o s c i l l a t o r s l u g u n t i l a m a x i m u m s i g n a l i so b t a i n e d o n t h e r e c e i v e r. F o r c l o s e r t u n i n g , i t m a yb e n e c e s s a r y t o a l t e r n a t i v e l y t u n e o s c i l l a t o r, t h e nt h e a m p l i fl e r ~ 4 d u b l e r , t h e n o s c i l l a t o r , e t c .

5 .

M e t h o d N o . 2

Th is method requ i res tha t agr id -d ip meter be used as an r. f .absorpt ion meter. Apply power, connect antenna, as above.

1. Remove the transmitter cover, after removing the l)-40 x3/16 B.H.M. screws.

2 . P lace t he g r i d d i p co i l pa ra l l e l and as c l ose as poss ib l eto the oscillator coil (that may be seen nearest the topo f t h e r . f . b o a r d ) .

R o t a t e t h e o s c i l l a t o r c o i l s l x i g u n t i l a p e a k i s o b s e r v e don the gr id d ip meter. Dae read ing o f the gr id meter in¬d i c a t e s t h e f r e q u e n c y o f t h e o s c i l l a t o r.

5 -

N O T E

I f d i f fi c x i l t y i s e n c o u n t e r e d i n p l a c i n g t h e g r i d - d i p c o i lc l ose enough t o t he osc i l l a t o r co i l , t he r. f . boa rd mayb e m o v e d o u t o f t h e e a s e w i t h o u t d i s c o n n e c t i n g a n y w i r e s .

5 - 5L I 2 7

S T - 2 A

f . A n r p l l fi e r - D o u b l e r T u n i n g

T h e M p l i fi e r - D o u h l e r n a y b e t m e d a s f o l l o w s ;

M e t h o d N o . 1

O p e i a t e t h e t r a n s m i t t e r I n t h e v i e i n i t y o f a r e c e i v e r .D e t a c h t h e r e c e i v e r a n t e n n a a n d t i m e t h e i h s p l i fi e r -D o u b l e r ® m i n g C o i l f o r i c a x i m i a a r e c e i v e r q u i e t i n g .T h e t r a n s m i t t e r s h o u l d n o w b e r e a d y f o r o p e r a t i o n .

1 .

Another approach to tuning^ and the one that is mostacc i rmte^ is to measure the d.c . vo l tage of the F.M.l l x a i t e r s t a g e i n t h e r e c e i v e r . T h e n t u n e t h e a a 5 ) l i fi e r -doub le r s tage un t i l amax imum d .c , vo l tage i s ob ta inedo n t h e v o l t m e t e r .

2 .

M e t h o d N o , 2

G r i d - d i p M e t h o d - T h i s m e t L i o d i s u s e d w i t h o u t a p p l y i n g a , c . p o w e rt o t h e t r a n s m i t t e r .

1 . R e m o v e t h e t r a n s m i t t e r c o v e r .

P l a c e t h e g r i d - d i p c o i l p a r a l l e l a n d a s c l o s e a s p o s s i b l et o t h e a m p l i fi e r - d o u b l e r c o i l ; , s e t t i n g t h e m e t e r a t e x a c t l yd o u b l e t h e o s c i l l a t o r f r e q u e n c y .

2 .

R o t a t e t h e a s ^ l i fi e r - d o u b l e r c o i l s l u g u n t i l a s h a r p d i pis observed on the gr id-dip meter. When the meter reachesi t s l o w e s t r e a d i n g , t h e a m p l i fi e r - d o u b l e r i s t u n e d t o t h es e c o n d h a r m o n i c o f t h e o s c i l l a t o r .

5 .

N O T E

T h i s x o fi t h o d i s o n l y a s a c c u r a t e a s t h e c a i . i b r a t i o no f t h e g r i d - d i p a r i e t e r .

L 1 2 7 5 - 1

S T - 2 A

1 | . M A I H T E N M C E

4 . 1 G i l H E R A L

The transmitter ST-2A, is designed to require minimum maintenance. Sincetransis tors are so ldered in p lace and submin iature techniques are used in theconstruct ion of the unit , l i t t le field maintenance is possible. I t is recom¬mended that, with the exception of minor repairs, such as broken leads andloose connections, etc., all mintenanee and troubleshooting be conducted inalaboratory. Sectional construct ion is used, where pract ical, in order tomake each component easi ly accessib le for serv ic ing.

4 . 2 TEST EQUIFMEHT

R e q u i r e da .

Simpson Model 260, or equivalent.RCA Vol tohmyst , or equivalent .

Kerns Clarke 1501^ e q u i v a l e n t .

V o l t - o h m - M e t e rV a c u u m T u b e V o l t m e t e rR e c e i v e r

O p t i o n a lb .

-Hew le t t Packard , Mode l 200AB, o r equ iva len t .General Radio, Type Ko. 546-C, or equivalent.-Measurements Corp . , Mode l No. 59 , o r equ iva len t .

Genera l Radio , or equ iva lent .

A u d i o o s c i l l a t o rM i c r o v o l t e r -

G r i d d i p M e t e rV a r i a c

4.3 GENERAL PRECAUTIONS

Whenever the unit is serviced, carefully observe the precautions listed(careless replacement of parts makes new faults inevitable)

Before apart is unsoldered, note the position of the leads,part, such as atransformer, has anumber of connectors, tag each oft h e l e a d s t o i t .

b e l o w :

I f t h e8> ●

Be careful not to damage other connections by pulling or pushing thel e a d s o u t o f t h e w a y.

Do not a l low drops o f so lder to fa l l in to the un i t j they may causes h o r t c i r c i u t s .

b .

c .

I t i s i m -Aca re less l y so lde red connec t i on may c rea te anew fau l t ,portant to use care in soldering^ since apoorly soldered joint iso n e o f t h e m o s t d i f fi c u l t f a u l t s t o fi n d .

d .

When apart is replaced in the r.f. section, it should be replacedexact ly as the or ig ina l on«| o therwise , changes in lead capac i tancem a y a f f e c t t u n i n g .

Use appropriate ranges on meters and test sets used for troubleshooting.

e .

f .

4 - 1

S T - 2 A

In rep lacement o f the osc i l la to r t rans fo rmer, care must be exerc isedi n t h e o r i e n t a t i o n o f t h e w i j i d i n g s .

g ”

h . I n r e p l a c i n g t r a n s i s t o r s , u s e a s o l d e r i n g i r o n w i t h a l o w p o w e rrating (22 l/2 watts). Excessive heat applied to atransistor leadm a y d a m a g e t h e t r a n s i s t o r .

4 . 4 S E C T I O I A L I Z I I G M D L O C i U : . I Z I H S A FA U LT

T h e fi r s t s t e p i n s e r v i c i n g a d e f e c t i v e u n i t I s t o s e e t i o n a l i z e t h ef a u l t ; i . e . , t o t r a c e t h e f a u l t t o t h e s t a g e o r c i r c u i t r e s p o n s i b l e f o r t h ea b n o r m a l o p e r a t i o n o f t h e s e t .

T h e f a u l t m a y t h e n h e i s o l a t e d w i t h i n t h a t s t a g e b y a p p r o p r i a t e v o l t a g e ,res is tance , and f requency meas t i rements . The tes ts l i s ted be low w i l l a id ini s o l a t i n g t h e s o u r c e o f t r o u b l e .

a . V i s u a l I n s p e c t i o n

The purpose of visual inspect ion is to locate any components whichshow evidence of mechanical breakdown. Through th is inspect ion, the repai r¬man may frequent ly discover the faul t or determine the stage in which thef a u l t e x i s t s . T h i s i n s p e c t i o n i s v a l m h l e i n f o r e s t a l l i n g f u t u r e f a i l u r e a n din avoiding damage to the uni t which might occur through improper servic ingm e t h o d s .

h . O p e r a t i o n a n d A l i g n m e n t Te s t

I t i s r e c o m m e n d e d t h a t t h e r e p a i r m a n t r y t o o p e r a t e t h e e q u i p m e n t ,as d i rec ted in Sect ion 3 , to de termine jus t what mal fuac t ion ex is ts and toc h e c k t u n i n g a n d a l i g n m e n t .

I n t e n a i t t e n t se .

I n a l l t h e s e t e s t s , t h e p o s s i b i l i t i e s o f i n t e r m i t t e n t s s h o u l d n o tbe over looked . I f p resen t , th i s t roub le my o f ten he made to appear byt a p p i n g o r j a r r i n g t h e u n i t . I t i s p o s s i b l e t h a t t h e t r o u b l e i s n o t i n t h et r a n s m i t t e r x m i t I t s e l f h u t i n t h e a u x i l i a r y a p p a r a t u s , o r c o n n e c t i o n s .

4.5 TROUBLESHOOTIIG GHART

The fo l l ow ing cha r t i s supp l i ed as an a id i n l oca t i ng t roub le i n t he un i t .Th is char t l i s ts the symptoms which the repa i rman observes, e i ther v isua l ly ora u d i b l y , w h i l e m a k i n g a f e w s i m p l e t e s t s . ! I l i e c h a r t a l s o i n d i c a t e s h o w t ol o c a l i z e t r o u b l e q u i c k l y i n t h e v a r i o u s s e c t i o n s .

Once t he t r oub le has been l oca l i zed t o as tage o r ac i r cu i t , vo l t age andr e s i s t a n c e m e a s u r e m e n t s o f t h i s s t a g e o r c i r c u i t s h o u l d s t i f fi c e t o i s o l a t e t h ed e f e c t i v e p a r t . N o r m a l v o l t a g e a n d r e s i s t a n c e m e a s t i r e m e n t s a r e g i v e n i n t h eVoltage-Eesistance Chart 4-6, which follows the Troubleshooting Ghairfc.

4 - 2

S T - 2 A

T R O U B L E S H O O T I N G C H A R T

S-YMPTOM P R O B A B L E T R O U B L E C O R R E C T I O N

T l , P r i m a r y v o l t a g en o r m a l . N o s e c o n d a r yv o l t a g e f r o m T l

P r i m a r y w i n d i n g s o f t r a n s -f o m e r w i r e d i n o p p o s i t i o n .

R e v e r s e c o n n e c t i o n

o f o n e p r i m a r y w i n d ¬ing. See F ig. L-5

O p e n T l p r i m a r y w i n d i n g Rep lace TL

C o n n e c t p r i m a r y w i n d ¬i n g s f o r 1 1 5 v o p e r a t i o n

F i l a m e n t v o l t a g ec o r r e c t v a l u e w i t h

1 1 5 v a p p l i e d t o i n p u t

U n i t i s w i r e d f o r 2 3 0 v .o p e r a t i o n

S o l d e r o r r e p l a c e i n ¬t e r c o n n e c t i n g w i r e .

L o w o r n o o u t p u tf r o m o n e p o w e r s u p p l ys e c t i o n , o t h e r p o w e rs u p p l y o u t p u t s n o r m a lo r h i g h .

O p e n i n t e r c o n n e c t i n g w i r e .

No aud io ou i5>u t S h o r t t o g r o i x n d o n a u d i oh o a r d c a u s e d b y e x c e s s s o l d e ro n f o i l , o r s h o r t e d b a s e - r fbypass CI5, CI6, or CI7.

C h e c k a u d i o b o a r d

r e s i s t a n c e s t o g r o i m da n d c o r r e c t s h o r t

Open coupling capacitor C9,CIO, or Gl l

F i n d o p e n c a p a c i t o rb y j i a n p i n g w i t h g o o do n e a n d r e p l a c e d e ¬f e c t i v e o n e .

Open transistor (col lectorvoltage same as supply voltage)

C h e c k c o l l e c t o r

v o l t a g e s a n d c o m p a r ew i t h s u p p l y v o l t a g e .C h e c k r e s i s t o r s

v i s u a l l y . R e p l a c ed e f e c t i v e t r a n s i s t o r .

V e r y l o w a u d i oo u t p u t w i t h o r w i t h ¬ou t d is to r t ion , (mayn o t b e a u d i b l e b u tw i l l s h o w o n o s c i l ¬

loscope) .

S h o r t e d e m i t t e r b y p a s scapacitor C12, CI3, or ClL.

C h e c k t r a n s i s t o r

v o l t a g e s . N o e m i t t e rv o l t a g e i n d i c a t e ss h o r t e d b y p a s s . C h e c kb y u n s o l d e r i n g s u s ¬p e c t e d c a p a c i t o r .V o l t a g e s h o x i l d r e t u r nt o n o r m a J . . R e p l a c ed e f e c t i v e b y p a s sc a p a c i t o r .

F i n d o p e n b y p a s s b yj i m 5 ) i n g w i t h g o o d o n e .R e p l a c e d e f e c t i v e b y ¬p a s s c a p a c i t o r .

L o w a u d i o o u t p u t w i t ho r w i t h o u t d i s t o r t i o n

O p e n e m i t t e r b y p a s s c a p a c i t o rC12, CI3, or Clk.

4 -3

S T - 2 A

C O R R E G T I O NS Y M P T O M P R O B A B L E T R O U B L E

P o o r o p e r a t i n g p o i n t o nt r a n s i s t o r c a u s e d b y ar e s i s t a n c e c h a n g e i nv a l u e o r o p e n r e s i s t o r .

C h e c k t r a n s i s t o r

v o l t a g e s t o fi n da b n o r m a l s t a g e .C h e c k r e s i s t a n c e s

o f a b n o r m a l s t a g e .R e p l a c e d e f e c t i v er e s i s t o r .

D i s t o r t e d a u d i o

o u t p u t

W o r . f . o u t p u t O p e n fi l a m e n t i n o n e t u b e C h e c k fi l a m e n t

v o l t a g e s . I f o n er e a d s I J v a n d o t h e rOv^ fi lament read ing1 3 v i s o p e n . R e p l a c ed e f e c t i v e t u b e .

C h e c k fi l a m e n t v o l t a g e s .I f n o v o l t a g e a c r o s se i t h e r fi l a m e n t , b u t1 3 v a c r o s s fi l a m e n ts u p p l y j ) o i n t s b o t ht u b e s h a v e o p e nfi l a m e n t s . R e p l a c eb o t h t u b e s .

O p e n fi l a m e n t i n b o t h t u b e s

Wo bias on tube(s) C h e c k g r i d t o g r o u n dr e s i s t a n c e . I f s h o r t

c i r c u i t , c o r r e c t s h o r t .I f n o r m a l , s u b s t i t u t et u b e .

Low bias (approx. -O.l^v) Jump C6 with goodc a p a c i t o r . I f b i a sr e t u r n s t o n o r m a l ,C6 is open. ReplaceC 6

Low bias (approx. -0.5v) Jump R2 wi th goodr e s i s t o r . I f b i a s

r e t u r n s t o n o r m a l , R 2i s o p e n o r u n s o l d e r e dR e s o l d e r o r r e p l a c e R 2 .

High bias (approx. -20v) onV 2 c a u s i n g c u t o f f .

Jxmip R1 wi th good re¬s i s t o r . I f b i a s r e ¬

t u r n s t o n o r m a l , R 1 i so p e n o r u n s o l d e r e d .R e s o l d e r o r r e p l a c e R l .

C8 open Replace C8C a n n o t b e t u n e d t o

p r o p e r f r e q u e n c y .

S T - 2 A

k.6 VOLTAGE-EESISTMCE CHART

Voltages in the parenthesis are measured witJa an RCA Volt-ohmyst. Othervoltages are measured with aSimpson^ Model 260, Volt-ohraaeter» All resistancesa r e a l s o m e a s u r e d w i t h a S i m p s o n ,

a. Power Transformer (Refer to Figure 3-l)

T h e s e m e a s u r e m e n t s w e r e m a d e u n d e r " n o l o a d " c o n d i t i o n s . I n o r d e rto test any t iansfor raer wind ing, i t must be d isconnected f rom the un i t .

P r i m a r y W i n d i n g sparallel (ll5v operation), their resistance is 400 ohms. VJhenin series (230v operation), resistance is 1600 ohms. The primarywindings are identified by tags Ho. 1, Ho. 2, Ho. 3; No. 4.

When the primary windings are connected in

S e c o n d a r y W i n d i n g s

T a g H o . ' s

Ho. 5 to Ho. 6Ho. 6 to Ho. 7Ho. 5 to Ho. 7 (C.T. connected) l60vHo. 8 to Ho. 9Ho. 9 to Ho. 10Ho. 8 to Ho. 10(C.T. connected)H o . 1 1 t o H o . 1 2

R e s i s t a n c eA . G . V o l t a g e

8 0 v 675 ohms675 ohms

1550 ohms6 o h m s6 o h m s

1 2 o h m s1 0 0 o h m s

8 0 v

l O vl O v

2 0 v8 v

b. A.F. Board (Refer to Figure 4-1)

Vo l tage -10^R e s i s t a n c e

min \ ; i s to gd .P l u s t o g d .T e s t P o i n t s

0 1

M(Em) to ZH(Base)to Z0(Col l ) to Z

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8 k 5 .5k- 1 . 5

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P(Em) to Z0(Base)to ZR(Coll)to Z

0 . 7 5 k 2 . 3 k-0.6 ( -0 .8) 7 k3 k

7 . 5 k 5 k“ 3 - 5

9 ^S(Em) to ZT(Base)to ZU(Coll)to Z

k 2 . 3 k“ 1 » 3 5-1.2 ( -1 .4) k 7 k3-5»4 7 k 3 k

* Te s t P o i n t " Z " i s g r o u n d .

4 -5

S T - 2 A

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R e s i s t a n c e

Vo l tage -10^ P l u s t o g d . M i n u s t o g d .T e s t P o i n t s

V I a n d V 2*

P in 1 (P la te )Pin 2(Screen)P i n 3 ( F i l . g d )Pin 4(Grid bias) to Z

(Grid drive)P i n 5 ( F i l )

62 5 . 3 k 1 0 0 kU O k

t o Zt o Zt o Z

45 1 5 . 5 k0 0 0

(-13)(l5rms)- 1 . 2 5

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5 5 k 53k

(Filament cold)8 o h m st o Z

6 2 3 k5 k

500 ohms

1 0 0 k1 0 0 k

I t o JK t o ZL t o Z

7 080 8 0 k

e. Lov Voltage BoaM (Refer to Figure 4-4)

- 5 . 0 1 . 5 k3 k

50 ohms250 ohms

1 5 o h m s + m e t e r t o + c a p a c .1 1 o h m s + m e t e r t o - c a p a c .

3 . 5 k4 . 5 k

15 ohms

A o r B t o ZC o r D t o Z

E t o FG t o ZH t o F

- 2 . 56 . 0

- 8 , 0 5 k- 2 . 5

* Te s t P o i n t " Z " i s g r o i m d

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P A R T S L I S T

M a n u f a c t u r e r ' s

N a m e a n d N u m b e rR e f .

P a r t N a m e , D e s c r i p t i o n , F u n c t i o n a n d L o c a t i o nS y m b o l

Capacitor, Fixed, Mica -l800jj.|ifd, 200v, (MV -F i l a m e n t b y p a s s c a p a c i t o r f o r V 2

Capacitor, Fixed, Mica -iSOO^fxfd, 200v, GMV -S c r e e n g r i d b y p a s s c a p a c i t o r f o r V 2

Capacitor, Fixed, Mica -l800p,fifd, 200v, -Screeng r i d b y p a s s c a p a c i t o r f o r V I

Capacitor, Fixed, Mica -l800ji| i fd, 200v -Filamentb y p a s s c a p a c i t o r f o r V I

Capacitor, Fixed, (Ceramic ~ 5 0 0 v - C o t Q ) l i n gcapacitor between VI afad V2

Mucon Co ip .H i K

C l

Mucon Corp .H i K

C 2

M u c o n C o i p .H i K

C5

C 4 Mucon Co ip .H i K

Mucon Corp .H i K

C5

C6 Capac i t o r, F i xed , M i ca -50p , | i f d , 500v -G r i d l eakb y p a s s c a p a c i t o r f o r V I

Capacitor, Fixed, Mica -68fi|jifd, 500v -Couplingc a p a c i t o r b e t w e e n a u d i o a n d r . f . s e c t i o n s

A r c o E l e c . I n c .

E lmenco DM- I5 -5OO-J

A r c o E l e c . i n c .

Elmenco DM-I5-68O-JC7

C8 C e n t r a l a b

DM-105Capac i t o r, F i xed , Ce ram ic - .O lu fd , I 5OVb y p a s s c a p a c i t o r

- r . f .

Capacitor, Fixed, Electrolytic -l|ifd, 60v -C o u p l i n g c a p a c i t o r b e t w e e n m i c r o p h o n e a n d b a s e o f Q 1

Ohmi te M fg . Co .IB-6OM

C9

Ij i fd, 60v Ohmi te M fg . Co .IB -6OM

C I O C a p a c i t o r , F i x e d , E l e c t r o l y t i cC o u p l i n g c a p a c i t o r b e t w e e n Q 1 a n d Q 2

Capacitor, Fixed, Electrolytic -l|j.fd, 60v -C o u p l i n g c a p a c i t o r b e t w e e n Q 2 a n d Q 3

Ohmi te M fg . Co .1B-60M

c n

C a p a c i t o r , F i x e d , E l e c t r o l y t i c - 2 5 j j , f d , 1 5 yE m i t t e r b y p a s s c a p a c i t o r f o r Q 1

P. R , M a l l o r yC 1 2ITHT

C a p a c i t o r , F i x e d , E l e c t r o l y t i c - 2 5 p f d , V y vE m i t t e r b y p a s s c a p a c i t o r f o r Q 2

P. R . M a l l o r yC I 3T N T

C 1 4 C a p a c i t o r , F i x e d , E l e c t r o l y t i c - 2 5 | i f d , 1 5 vE m i t t e r b y p a s s c a p a c i t o r f o r Q 5

P. R . M a l l o r yT N T

C a p a c i t o r, F i x e d , C e r a m i c - . C l j i f d , l ^ O v -r. f . bypass t2apaci tor in base of Q1

C e n t r a l a b

DM-103C I 5

5 - 1

S T - 2 A

R e f .

Symbo lM a n x i f a c t u r e r ’ s

H a m e a n d N u m b e rP a r t N a m e , D e s c r i p t i o n , F u n c t i o n a n d L o c a t i o n

C l 6 C a p a c i t o r, F i x e d , C e r a m i c - 5 0 0 ! i j i f d , ' ^ O O y - r. f ,b y p a s s c a p a c i t o r i n b a s e o f Q 2

Mucon Co ip .H i K

C17 Capacitor, Fixed, Ceramic - 5 0 0 " ' ^ ” ^ r ' . f .b y p a s s c a p a c i t o r i n b a s e o f Q 3

Mucon Corp .H i K

Cl8a,b , c

C a p a c i t o r , F i x e d , E l e c t r o l y t i c - 2 0 j i f d x 2 0 } i f d x2 0 ( i f d , I 5 O V - P o w e r s u p p l y fi l t e r c a p a c i t o r

S p r a g u e P r o d . C o .

C I 9 C a p a c i t o r , F i x e d , E l e c t r o l y t i cP o w e r s u p p l y fi l t e r c a p a c i t o r

lOOpifd, lOv - F a n s t e e l M e t .P P 1 0 0 B 1 0 A 2

C 2 0 C a p a c i t o r , F i x e d , E l e c t r o l y t i cP o w e r s u p p l y fi l t e r c a p a c i t o r

lOO^fd, lOv - F a n s t e e l M e t .P P 1 0 0 V 1 0 A 2

C 2 1 C a p a c i t o r , F i x e d , E l e c t r o l y t i c - l O O i i f d , l O v -P o w e r s u p p l y fi l t e r c a p a c i t o r

F a n s t e e l M e t .P P 1 0 0 B 1 0 A 2

C 2 2 C a p a c i t o r , F i x e d , E l e c t r o l y t i c - 2 5 0 | i f d , l O v -P o w e r s u p p l y fi l t e r c a p a c i t o r

F a n s t e e l M e t .

PP250B10A2

C23 C a p a c i t o r, F i x e d , E l e c t r o l y t i c - 2 5 0 | j . f d , l O v -P o w e r s u p p l y fi l t e r c a p a c i t o r

Capacitor, Fixed, Ceramic -800(j,p,fd, lOOOv -r.f.b y p a s s c a p a c i t o r i n P o w e r S u p p l y

Capacitor, Fixed, Ceramic -800jij4fd, lOOOv -r.f.b y p a s s c a p a c i t o r i n P o w e r S u p p l y

Capacitor, Fixed, Ceramic ~SOO^jifd, lOOOv -r.f.b y p a s s c a p a c i t o r i n P o w e r S x 5 ) p l y

Capacitor, Fixed, Ceramic -800jififd, lOOOv -r.f.b y p a s s c a p a c i t o r i n P o w e r S u p p l y

Capacitor, Fixed, Ceramic -800}i|ifd, lOOOv -r.f.b y p a s s c a p a c i t o r i n P o w e r S u p p l y

F a n s t e e l M e t .

PP250B10A2

C24 C e n t r a l a bDD-801

C25 C e n t r a l a bDD-8O1

C26 C e n t r a l a bDD-801

C27 C e n t r a l a bDD-801

C28 C e n t r a l a bDD-801

C29 Capacitor, Fixed, Ceramic - .005p, j i , fd, 25v, GMV -r . f . b y p a s s c a p a c i t o r b e t w e e n b a s e a n d c o l l e c t o r o f V I T O O 5 R

Mucon Corp .

D 1 Diode, Germanium -Rect ifier in P la te Vo l tage PowerS u p p l y

G.E . 1N93

D 2 Diode, Germanium -Rect ifier in P la te Vo l tage PowerS u p p l y

G.E . 1N93

5 - 2

S T - 2 A

M a n u f a c t u r e r ' sH a j n e a n d N u m b e r

R e f .

Part Hfljne, Descr ipt ion. Funct ion and Locat ionS y m b o l

G.E. 1E91Diode, Geimanium -Rectifier in Transistor VoltageP o w e r S u p p l y

Diode, Germanium -Rectifier in Filament VoltageP o w e r S u p p l y

Diode, Germanium -Rectifier in Filament VoltageP o w e r S u p p l y

Coil, r.f. -58|jh -r.f. choke in power supply

D5

G.E. 1N91Dl

G .E . M50 .D 5

W i l c o C o i p .3038-15

L I

W i l c o C o r p .3038-15

Coil, r.f. -38{ih -r.f. choke in power supplyL 2

W i l c o C o r p .3038-15

Coil, r.f. -38(jh -r.f. choke in power supplyL5

W i l c o C o r p .3058-15

Coil, r.f. -38|jh -r.f. choke in power supplyL l^

W i l c o C o r p .3058-15

Coil, r.f. -38|jh -r.f. choke in power supplyL 5

Resistor, Fixed Film -10k, 1/20W, 10^ -Screend r o p p i n g r e s i s t o r f o r V 2

Resistor, Fixed Film -10k, 1/2OW, 10^ -Screend r o p p i n g r e s i s t o r f o r V I

Resistor, Fixed Film -35k, I/2OW, 10^ -Gridl e a k b i a s r e s i s t o r f o r V 2

Resistor, Fixed Film -100k, 1/20W, 10^ -Gridl e a k b i a s r e s i s t o r f o r V I

Resistor, Fixed Film -10k, I/2OW, 10^ -Baseb i a s r e s i s t o r f o r Q 1

Res is to r, Var iab le -5k -Dev ia t ion Sens i t i v i t yA d j u s t m e n t

Resistor, Fixed Film -10k, I/2OW, 10^ -Baseb i a s r e s i s t o r f o r Q 3

Resistor, Fixed Film -l4k, I/20W, 10^ -Baseb i a s r e s i s t o r f o r Q 1

A m h o l d C e l t i c sStemag T^e R

R 1

A m h o l d C e r a m i c sStemag Type R

R 2

A m h o l d C e r a m i c sStemag TJpe R

R3

A m h o l d C e r a m i c sStemag O^ype R

R 4

A 3 m h o l d C e r a m i c sStemag Type R

R5

A l l e n B r a d l e y C o .F - I - 0 0 9 - U

r 6

A m h o l d C e r a m i c sStemag lype R

R7

A m h o l d C e r a m i c sStemag Type R

R8

5 - 5

S T - 2 A

M a n \ i f a c t x i r e r ' sN a m e a n d N u m b e r

R e f .

P a r t N a m e , D e s c r i p t i o a , F u n c t i o n a n d L o c a t i o nS y m b o l

Resistor, Fixed Film -10k, 1/20W, 10^ -Baseb i a s r e s i s t o r f o r Q 2

Resistor, Fixed Film -15k, 1/20W, 10^b i a s r e s i s t o r f o r Q 3

Resistor, Fixed Film -If.7k, l/20¥, 10^ -Collectorl o a d r e s i s t o r f o r Q 1

A n i h o l d C e r a m i c sStemag Type R

R9

A m h o l d C e r a m i c sStemag Ilype R

B a s eR I O

A m i i o l d C e r a m i c sS t e m a g T ^ e R

R l l

k.Tk, 1/20W, lOio -Emitter A m h o l d C e r a m i c sStemag OJype R

R e s i s t o r, F i x e d F i l mb i a s r e s i s t o r f o r Q 1

Resistor, Fixed Film -if.7k, 1/20W, 10% -Collectorl o a d r e s i s t o r f o r Q 2

Resistor, Fixed Film -2.7k, 1/20W, 10% -Emitterb i a s r e s i s t o r f o r Q 2

Resistor, Fixed Film -3.9k, l/20¥, 10% -Collectorl o a d r e s i s t o r f o r Q 3

Resistor, Fixed Film -Ik, l/20¥, 10% ~Emitterb i a s r e s i s t o r f o r Q 3

Resistor, Fixed Composition -I5 ohms, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Con5>osition -1.2k, l/2¥, 10% ~P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Composition -1.2k, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Composition -I5 ohms, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Composition -2.2k, l/2¥, 10% -P o w e r S i p p l y fi l t e r r e s i s t o r

Resistor, Fixed Con5)osition -4.7k, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Composition -I5 ohms, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

Resistor, Fixed Composition -I5 ohms, l/2¥, 10% -P o w e r S u p p l y fi l t e r r e s i s t o r

R 1 2

A m a h o l d C e r a m i c sStemag ^ype R

R I 3

A m h o l d C e r a m i c sStemag Type R

R14

A m h o l d C e r a m i c sStemag Type R

R I 5

A m h o l d C e r a m i c sS t e m g Ty p e R

R16

A l l e n B r a d l e yR I 7T R

A l l e n B r a d l e yR18T R

A l l e n B r a d l e yR I 9T R

A l l e n B r a d l e yR 2 0T R

A l l e n B r a d l e yR 2 1T R

A l l e n B r a d l e yR 2 2T R

A l l e n B r a d l e yR23T R

A l l e n B r a d l e yR 2 l fT R

5 - 4

S T - 2 A

M a m x f a c t u r e r ' sN a m e a n d H l n a b e r

R e f .

P a r t N a m e , D e s c r i p t i o n , F u n c t i o n a n d L o c a t i o n

Resistor, Wirewoimd -59 ohms, 5W, 5^ "PowerS v r p p l y fi l t e r r e s i s t o r

Trans is to r, PNP Gemnan ium -F i rs t Aud io Ampl i fie r

S y m b o l

SpragMB. Prod. Co.B l u e J a c k e t

R25

L a n d s d a l e T u b e

Philco 2N20?BQ1

L a n d s d a l e T u b e

P h i l c o 2 N 2 0 7 BTransistor, PHP Germanium -Second Audio Ampl ifierQ2

Transistor, PHP Germanium -Third Audio Amplifier L a n d s d a l e T u b e

P h i l c o 2 N 2 0 7 BQ5

S p e c i a lTransfo imer, Power -Power TransformerT L

Tr a n s f o r m e r, R . F. - O s c i l l a t o r Tr a n s f o r m e r S p e c i a lT 2

Tr a n s f o i m e r, R . F. - O u t p u t Tr a n s f o r m e r S p e c i a lT 3

R a y t h e o n1AD4 or equlv.

V I T u b e , E l e c t r o n - O s c i l l a t o r

Tu b e , E l e c t r o n - A n p l i fi e r - D o u b l e r R a y t h e o n1AD4, or equiv.

V 2

5 - 5