I I I I I I I I ,

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[:;;d A

-IAIHPAllltlT i TlClllCAL IAIIAL

L ':>

KEYERS TG-lO-A,

G-lO-B, TG-lO-C, TG-lO-D,

G-lO-F, TG-lO-G, TG-lO-H,

AND TG-lO-J

I 'AR DEPARTMENT • 27 MARCH 1944

WAR DEPARTMENT TECHN I C A L M ANUAL

TM 11~441

TI ~ _..I ,.,..,ol" TM 11-441. C"., re_I"'} (.1_"",, 6IJ C .. J.,) _I C,-, TG-I ... .I, TG-1 ... 8, TG-It-C, TG-I ... D. re_I ... ' , JJ M., IHI _. II .1_,,,, 1\>/1, .,,101;., S. ,.,.~ ... N~ I, II .I .. ." ml,

KEYERS TG-IO-A.

TG-IO-B. TG-IO-C. TG-IO-D.

TG-IO- F. TG-JO-G. TG-JO-H.

A N D TG-JO-J •

•

WAR DEPA R T M ENT • Z7 MARC H 1 944

u.w..t _, c-.""" ".;.n .. ()~"

...... 1., ... , I""

~ -UN IV[RlfTY Of CALIfORNIA

, WAR DEPARTMENT,

W,\6HlNOTON26, D. C., 27 March 19-14.

TM 11447, Keyera TG-l{}-A, TG-l()-B, TG-IG-C, TG- tO- D, TO-tO-F, T(}-lo-G, TG- Io-H, and TO- lO-J, ill published for the information and guidance of all oonC(lmoo.

IA. o. _ 1 (JD Oct <3).J

By OROER or TlIl!: SECRETARY or WAR:

OrnClAl.:

O. C. MARSHALL, Ch.uf of Staff·

'J. A. ULIO, Major rkno-rd,

TM Adjukln! tkMral . DIIITRIIIUTION;

.M preacrihed in par: 9a, FM 21-6; Bo and Ii 1, 2, 4, 6, 7, II, 17,18 (2); Ie 11 (2) ,

10 II: TjO 11- 267, Sig Co, AAF T ID 11- 217 , Sig Co Avn T ID 11- 287, Sig Co Depot Avn TID 11- 77, Big Co Rat! lnt TID 11- 287 , Sig Co Sv Gp T ID 11-247, SigCa Wg TID 11-47, Sig 1'r Cay Div TID It-57 , SigQ) Armd Div TID 11- 7, Sig Co lnf Div T ID 11-317, Sig Co Mt Div T to 1 HI?, Sig Co Operation T/O 11- 18, Sig Co Operation Wire Annd T /O IH5, Sig Cc;I Hq Co Bn Sig Co Rad Armd &ig Co M~ Div Sig Fixed R&d St& Co

(For explanation of aymbo~ BOO !<'M 21-6.)

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Contents Tf1//: ?¢7

/<;--.1-1

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SECTION I. DI!:ScaIPTIOl'f <len~ _____ __ ___ . _____ _______ • _____ ___ •• ____ _

DiJfe..en< !1 ____ ______ .n ._ n . ___ .un __ n _____ _

ComponllDt., weight., and dlmenalo ..... _. _. __ , __ __ • Power oupply ____ __ ____ ___________ ____ ._._. __ "__ Controll ____________ _________ __________ __ __ . __ _

D. INSTA.LLATION AND OPEaATION

llli~iaI p...-lUl'fl ____ • ____ , __ __ ____ • • __ , ______ _ In~uoG _____ ______ ________________________ _ Preparation for u"", _ ____ _ _ __ +_. _____ ._ . _. __ _ _ Ope,"io". __ __ . ______ , __ __ _ , _. ___ ____ __ + •• _ _ ••

Adj U8tmento for 6eld upk""p __ __ _____ _____ ______ _

m. FUNCTIONING or PAaT!I Power .... it.cL. _____ ___ ___ ____ _______________ _ _ Vollqe amplifler. __ . ____ ____ ___ __ __ _____ __ __ _ _ ~.tor._ .. _____ . __ .. _. ___ _____ ______ . __ __ _ _ Po ... ..,. .",pli6e' ______ · _____ ___ __ _______ __ __ _

IV. H.uNTENANCE Prevenc.lve maln«on""001 __ ___________ _____ . ____ _ _ Setvicln« ____ . ___ ____ ______ __ __ __ . __ _________ __ _ l<ibrieation cha.I"\ . ________ ___ ___ _______ ___ ___ __ _ TrnuWe loeatlon ch~ ___ _______ ______ ____ _____ _ Pnint..to-pomt d..., voltag",, ___________________ ___ _ Pol nt.-to-point -"'~ ____ ___ ____ _ .. ___ ____ __ . __

lnotJv.ctJona lor IUlllliprnofillll ..... d iDOLstunoproollnc __

V. SU.PUHII:NTA&Y DA.TA.

T able of repl..,e.b(c pv\oI. __ n n_ •• n_ . _nn _ u.

N'meo ..... d ~ of manuf&<:tu ..... u un n n _ _

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M558576

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Destrudion Noti~e

WHY- To prevent the IlI)C1ny from ",ring or salvaging t.bia equip­ment for bis benefit.

•

WHEN-When ordered by your commander.

BOW-I. Sm'llb Use sioogtlll, II.XIlII, hud liLlU'JIJ, pickaxes, ham­men, crowbal1l , heavy tools, etc.

• %. Cut Use axes, hand axl'tl , machetell, etc . •• Burn Use ga.l!Olinll, kel'Ollene, oil, Bam!! throWlll1l, in_

cendiary grenlldeol, etc. &. t:lplosiftS Use firearms, grenades, TNT, etc. I. Disposal Bury in slit trenches, fox holes, other holes.

Throw in lI!.reams. Sc.tt,er.

Use InftMo, immediately ."aUable tor destruction or tbls equipment.

WHAT- I. Smash All vacuum t4be&, oontrole, diala, reels, kWH-

fonnenl, and relays. I. Cut All connecting wireR, cables, etc. I. Bend and lor break Jacu and plUg!!. , ,. Burn All of the above equipment, training mllDuals,

records, etc. I. BUI'J' or scatter Any or all ol.bove pieeee after wreck- '

ing th6IIl.

DES'J'RO¥ EVERl''J'R.NC

SAljjty NOTICE

Sinu tk ooltagu tmplcytd in tAil eqvi~ art ..ufficientlll h.igh. k> endanger life, twl' r~tmabk pruaution Iuu Iulen 006trwl in tk~ to ao:/tguartl 1M operating perlOnnd. Cart m1Ut Iu taken, ~, to aroid bodily Mrnl thr01Jf1h, C01IIact 10itA high-wlmge pWk circum, (]I' with ~ prMer ptanl utdput li~.

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T~'" ... n ....... ~_""""" TJI 1I-ut, K.,..... IT_If-} ( ....... , ..... ,/0-, ... r..,. .... ) wn" K.,..... TC-I ........ , TC-I-. 7T._I .... ~ TC-If-". TG-,f-F, IJ JI ... l'U-.llJ ... ~ .... , Ius. low' ........ "~g"_' ."'~,." ...... _. J~

Section I Desuiption

1. GENEItAL. ., Purpose. K"yer TO-IO--(&) is ftn aUwmftti(' unit for providin~ audible oodl" pnu\tic,(\ signals from an inkf'(l-ta~ recording, and is included in and is a part of Code Practice Equipment E"&-94-B, EE--95--B, and EE-OO- B. The Bymbol (&) !"(Ofer1l to all modeJB of Keyer TO-IO, that is, models A, B, C, D, F, G, H, and J. There is no model E or model I. For Bimplicity, models A, B, and C a!"(O referred to as Keyer TO-to-(l ), and models D, F, G , H, and J a re referred to &8 Keyer TO-I0--(2). The output of Ksyer TO-IO- (d-;) is an audio frequency nolAl of 800 cycles per 8000nd with Bufficient power to 8upply a number of headsets, 500 to 1,000 if necaSf"ry, or practice tables dirootly. Thl" keyer, a self-contained unit, ill ready for operation when connected to power maillS and headsets dirootly or through praetice I.8.blllll.

b. EJ;~rnal keytn,. Keyer TO-to-(&) mBy also be open.ted by an exlAlrnal tel~ph key, eitJler manual or automatic, supplying 500 W 1,000 headsettl with an SOO-cycle nOIAl. When SII exlAlrnsi key is used, tlle I.8.pe mechanism should not he operated.

c. Ink recordln,. Except for Keyer TO-tO-A, Keyer TO-IO-(.t) ill equipped with suil.8.bls guide and pre88ure rollers, which pennit its use witJ, anyone of several type8 of ink recorders when nODe is furnished with the I.8.pe-pulling mechanism (par. 9d). 2. DlFFERENcm. All models of Keyer TG--Io-(.t) .re mechBni­cally and eiootri('8IJy similar. Di1ferences &nl explained below and ehlewhere in this mlln ual .

•• Keyer1l TG-Io--B lind TG-IO--C are idf'ntical. ~ Keyers TG- Io-A, TG- Io--B, and T G-IO--C are identical except

thllt the power and IillUDent trlUlsfol"IIletS and the motor of Keyer TG- IO--A are wound for 26-cycie instead of 6!M:ycie cu r!"(Ont.

c. Keyer TG- Io-(2) di1fers from olJJ.er models in the following IllIIpooltil:

( I) The motor, cone, driving Jl.98Bmbly, and relllted pa.rI.8 &nl mounted differently. (2) The speed indicator 8 896mbly ill difl"enmt.

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}",,,, u 1. K,,,.. Tf'.-/tJ-(IJ.JrMll "" r.

F,,:n;RI 2. ,..~ TQ-I I)-('). JroRl .i,",.

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<.. H I

(3) A di&llarnp haa bean added. (4) A slotted, screw-driver bias adjustment ·(26) - (fig. 4) haft been added, giving two bias adjustments (26) and (40) (fig. 6). • (5) A mot(lr switcil (43) (fig . . 2) has been added. . (6) An additional roller (99 (T» (fig. 2) haa bt>~n sdded. (7) Reeist(lr (39) (figs. 8 and 11 ) (4,OOO-ohm) replaces resistor (27- 1) (figs. 7 and 11 ) (4,700-ohm). . (8) Resistor (27) (figs. 8 and] l) (2,500-ohm) replaces resistor (27- 2) (figs. 7 and] I) (4,700-ohm). (9) Resistor (40) (fig. 8) (200-0hm) hIlS hoon added.

d. Resistors (36-1) (250-0hm) and (36-2) (250-0hm) have bGAn added (fig. 8) on Keycr TG-Io-J.

3. COMPONENTS, WEIGHTS, AND DIMENSIONS. a. Com­poneni.ll, weighi.ll, and dimllmrioIlll of Keyer TG-Jo-(d:) are IiaWcl h~low:

-, .. MulmlLlD •• ......u d __ 1Ddudll>!

-----,---~

I Keyer TG-- IQ-(&): Keye. TG--IQ-A __ __ __ _ Key". TG-- IQ--B. C •• ••. Keye. TG--IQ-(2) ••• ••

I Set vacuum tul>"'l:

:'~f!' , ,

--,~ 2 tu~_. ___ ••••• _. _ ____________ __ _ VT--t16 2 tul>"'l _____ _ _ __ ____ __ ____ _________ VT- 1I5 2 tube. . _. ___ _ • _. _ . __ _ • _ ___ •• ______ VT-116 I tube ______________________ ___ _ ___ VT-:H~ 1 tube ___ ____ _ __ ____ • ___ ___ _______ _ VT- 252

2 Tapes, Inke<! 1"-"'" 3 Reel_, tak .... llp

'" " " ~-~ -'" "" .."

5U4-0

'" NOT~: A"""""" ..... nlqllired are a monlt<lri~, he&d.oet aad an ""ternal key.

b. Keyer TG-Io-(&) is mounted in a cabinet, /L9 shown in figlU'es I and 2.

c. Removed from the cabinet, the keyer fit. a standard Ill-inch relay rack. The height of the panel is 8Y. inches. Keyer TG-lO-{&), eJ[cept Keyer TG-IO- A, weighs 40 pounds without ita cabinet. Keyer TG-Io-A, without the cabinet, weighs 47 pounds.

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·N""" ..... 1n __ .-"' .... 01lIII0 OOl"l_' .. _. IRI'''''''''''pbo''''' "'P'= 'IlL "b . .... t.bIo - - .uol.

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4. POWER SUPPI. \". KI'~w TG- Hl- (& ), C)(CCI)t Keyer TG-IO-A, oJl(!J'atC!l on 115-volt, G()...(:ydc alternat ing currcnt. A ,'oittlgc \'II.ri ­at ion within the ranI;C of 95 to 120 \'oh~ ",ill not eubstllntially affect t ho operation of tl\e illlltrument. Keyer TG-LO- A oJl(!ratC!l on 110-volt, 25-cyclc alternating ... urrent.

5. CONTROLS. Controi~, adjustments, 5witches, and other pftrts on the fron t panel a re---

a. A mlmitor jftck (8) (figg. 1 lind 2) for plugging in II headset when ad justing the bias and phototuoo aJl(!rture, o r for monitoring whl'n keyer is in o l)('nltion,

b. A ~olum~ cOlltrol (20) (figs. 1 ~Ild 2) with sloHed &hftft for serew driver Il.dju~tmellt .

.... A hi"" I.. control (105 (L)) (figs . I ftnd 2), to provide II fi ne ".1-jWltment of bias afler bi llS control (26) . (fi g. 4) on the chllSBis hM ~Il adjusted.

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d. A powt,'-<JjJ-luy-4l1pt switch (1M (R )) (figs. I ftnd 2). e. I'hototube and aperture IIdjustrnellt (59) (fi gs. 1 and 2). I. J>hototuhe housing (56) (figs. 1 lind 2). g. T ap!'-rcwind mechllnism (103) (fib"" L /lnd 2) .

0.'9' .r I<om UNIVE~SITY Of CALIfORNIA

h. T"I)C rre[~ ( 123 (U )) Hud (123 (L» (fib'>! . 1 Hud 2 ). I. Mirror housing (62) (fib'"$. I li nd 2). J. T ,,[»-speed iudieat-or d illl (94 ) (figs. I !Iud 2)~ k. TIII)C-SI)Ccc.i indiellt.-or control (100) (fib'"!! . I lind 2). I. Ta.pe-puller roller (79) (figs. I find 2 ). m . Tllp-e~ontent preMure roller (85) (figs. I lind 2). n. T flke-u [l r()(!1 d rive belt (98) (figs. I flud 2 ). o. T llke-up reel sh.ft IIssembly (96) (fi gs. I lIud 2). p. ~ Iotor O FF-ON swit("h (43) (fig. 2) (;", Kl'yer T G- 10-(2) \lnly ). q . TS!}e guide ':Oilers {99 (1..» IIIl1I (9!) (H)) (fib'll. I Klld 2). r . Tfll)C guide roller (99 (T)) (fig. 2).

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• Sedion II

Installation and Operation

.. INITl.U. PIlOCEDUBE. ... Unpacklng. Kayer TG-l(}-(4:) ill packed in an indiv:idual carton. The unit may be removed by opening the carton at the top, c&refully removing the cardboard blocking pieces from the front MId &idee, and lifting the cabinet from the carton.

b. Tubes. A set of vacuum tubee, exelusive of the photoolootric cell and exciter IalXlP, is in a l!eplLI'&te cardboard oonte.uleT isaued with the byer and marked "Tube Set for Keyer TG-to-(ol)." Inside the carwn are seven vaeuwn tubes, each sePaTately packed and marked with itll tube number. A IiBt of these tubeR ill given in p&rfl_ graph 3a. MUIr the tubes have been UIlpack~, insert them in the proper IIOcket8 on the cbueis. The keyer is IIhlpped with the photo­e100trie cell and exciter lamp already irustaDed.

7. INST.4.U ·4.T10N. •• SeledloD or output. Three output impedances are provided at the output terminal board ~35) (figB . 3 and 4) on the ro&I' of the chS98iB. Impedance of ., 8, or 15 ohlllll may be selootad by oonnecting to the oornrnon tenninal and the Wrminal with the deeired impedance. The moat auitable ma~hiDg impedanw may be detonnined from the number of headllOts w be oonnooted w t he keyer and the impedance of each. If many hoadaetiJ are U86d., the 4-ohm output termin&l. ill most Buitable. If only a few headsets II.fO oonnooted, the 15-0lun output wnmn&l. is preferable. Try aJ.l output Wrmin&I.B and use the one giving most 118.ti6Ia.ctory operation. The power used by one head!!et iB oonsidered about 5 milliwlI.tl.!!.

b. Wlrlng. (I ) TABLE MOUNTING. If the keyer is to be oporetod from a table or bench, place it in JIOIIition and run a pair of leadB from the output wrminals (35) (figs. 3 and 4) to the vohune­control board (sometimOll called & pat<::hing board). (lnfonnation on wiring of the volume-oontrol board mlly be found in TM 11-432.) Plug the power oord into the rooepte.cle (1I) (figs. 3 and 4) on the rear of the chlllllliB, and'inoo a convenient power outlet. (2) RACK MOUNTING. If I16ver&l. byers are to be mount.ed oogether on a standard rolay rack, remove the unit from the cabinet by firIIt rEllllOving the &creW!! (134) (figa. I and 2) on the endB of the

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PfUlei, and then the three !ICl'eWII holding the rear of the ch"eie to the bottom of the cabinet. The panel and chappip ILt6 f&awned together 110 that the kflypr CIIll be mounted, using the pfUlpl ~, to the relay rack. lnBtaU external wiring as deecribOO in (1) above.

&. PREPARATION FOB USE. a. Adjustment of IIcbt pte. The removable cov.lr (69) (.6~. 1 fUld 2), inclosing the phototube, contains a ama.ll aperture or opening, through whicll light pll8llee. The position of the aperture under the tape ie adjusted by eliding thfl oo,'er in or out, fUld locking it in position with the knurled nut (165) (figs. 5 a.nd 6) below it. To adjust the position of thia aperture, fold the tape at a point COlTCBponding to a epaee between dots and dMhllll , which BII a rule is at the point where the inked . line is oJ.f the eenter of the tape. By plfl(:ing the end of the tape nen 00 the light aperture, the oover can be manipulated until the hole is opposite the middle of the inked line.

b. Tbreadlng. When the rewind mechfUlism (103) (fi~. 1 lUld 2) is pulled forws.rd , it will allow a full reel of tape (123 (R» (figs. I and 2) 00 be put in place. (Wind the reel 110 t.hat the ink....:! aide of the tape faeca the hub of the reel. ) Hole the reel, with tbe square driving hole ffl(:ing the operfltor and the free end of the tape PU8pended at the operlltor 's right aide. Snap the reel in .plo.ce over the ball Cfl.t.ch, witb thll square driving bole W .... llrd the emnk, af!d return the rewind mechanism 00 itIJ original position wit.h the reel vertical. Di8('n~ the pressure roller (85) (figs. 1 fUld 2) from tho puller roller (79) (fi~. 1 and 2) and J>iIN' the t.ap", inked side up, under guide roller {99 (R» (figs. I and 2), over the light gate (59) (figs. 1 and 2), under guide rollor (99 (1..» (figs. I and 2), 00 the left of guide roller (99(T» (fig. 2) (nolr on Keyer TO-Io-(I)) and over the puller roller (79) (figs . 1 and 2). Insert the end of the tape in one of the 810~ in the huh of the take-up reel (J 23 (L)) (figs . I fUld 2) and, turning the wheel by bfUld to the right, wind on II. few layenl of tape.

t.OPElLATION. a. Tape keying. (1) START. Turn the rotary 8witch knoh {los (R» (figs. I and 2) to TAPE, 00 start the motor and amplifier. Allow the seL to warm up fOf a few minutetl. To '~ngage the drive, lo .... er the pressure roller (85) (figs. I and 2) . The tape will then be forced tlgll.inat the puller (79) (figs. I MId 2), IUld the keyer will reproduce the signal rooorded on the tapa.

(2) BIAS. With the tape running, plug a headset inw the MONITOR jack (8) (figs. 1 and 2). With the BLAS knob {l05 (L» (figs. 1 and 2) vertical, use a IICfew driver to rotate the hiBII control (26) (fig. 4) (located. on the ehll8llie 00 the left of mowr (42) (fig. 4» on Keyer TG-lo-(2) until a clear signal is heard. (On Keyer TO-I (}-(I) rotate the bias oontl"ol knob (105 (1..» (fig. 1).) If the oontrol is turned too

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far to the left, no signa.! will be hew, or if it is turned too far to the right IlIIte&d.y ~ign.1 will reIIult. The COlTOOt position is between these erlremes. The adjustment lIhould not be critical. If the bi .. control require& II very elOBe III)tting, mcbeck the adjustment of tbe light gate. Sine(! the line voltage supplying the keyer ch"nges, it may be nece:!flry to reset the biae control. The BIAS knob (10:1 (1..» (figs. 1 and 2) provides .. fine adjustment of tbe bi .. , and is used in nonnlll operatioD of the keyer, after the biae control (26) (fig. 4) on the cbuf!iB haa boon properly adjUlltOO.

(3) VOLUM:E. The vohllDe of the signa.! delivered to the practice tables may be varied by the &Crew driver adjWltm(lnt (20) (figs. 1 and 2) marked VOLUME. Turning to the right Wcre&I!eII the volume.

(4) TAPE SPEED. The speed control knob (100) {figs. 1 and 2) controiB the rate of speed of the tape and the speed of the tranarniasion. Before turning the epood oontrol knob , d~ tJw tapt-fud Uv lifting tJw preuw-t roller (85) ·(1ig8. I and f). Tbe indiClltor dilll (94) (figB. 1 and 2) is ealibrated in feet per minute to indicate the linear speed of the tape.

NOT",.-h ""'Y !:>ol DC~ ' T ry 10 imp ....... in order 10 t..,p the t&Pft taut while tbe wlit ~ h. ope .... tlon. ~ ... y ill 10 plaee • Jl"'Pftr ollp unoo t!:>ol top JI"'""I lI(l~" (lip.. I BI>Ii 'Z) and bendin, It., It My &I. bnob on t.be I"I'!oCl (123 (ft») (lip. I and 2).

(:I) MOTOR SWITCH. On Xeyer TQ-Io-(2), when wring the keyer as a tape puller with II. eeparat.e inker, tbe motor switch (43) (fig. 2) will permit turning the motor on rogardlC88 of th,· position of the rotary swilA:h (105 (R)) (fig. 2).

b. Bewlodlnl. To return the tape to the m&gazine rool (123 (R)) (figs. 1 and 2)- .

(I ) Di8engage the drive by moving the prell8urc roll..,. (85) (figs. 1 II.lId 2) upward and away from the puller roller (79) (figs. 1 and 2).

(2) Remove the tape from the puDer roller tIO that it feeds from the reel (123 (L)) (figs. 1 and 2) to the gliide roller (99 (L ») (figs . I and 2) under the phototube hOWling and dirootly to the guide roller (99 (R)) (figs. 1 and 2).

(3) To return the tape, tum the handle of the rewind mechanism to the right. .

NOTII.- Do I10t ~"';Dd tbe tBp" 100 rut. Or It IIIAJ" !:>olio .... and tllo nowhld!n@ ,....,. dBJnA86d. K .. " lIw /<JIH /<Jill.

e. Elteroal key:l0l' To tranam.it the signal of & mllllually oper. atOO key to the pl"8.(".tiee t.ftbICll , turn t he rot.ftry switch knob (105(R» (figs. 1 and 2) to KEY {eonnectOO to the KEY tenninals (10) (figs. 3 and 4) on the rear of !.he oh"·il). With mllDual kuying the bias

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cOlltrol is out of the circuit., hut Ihp volume control rnnclion~ e:mctly 11K it does with tallC keying.

d. Tape pul,lIng ror Ink r~order. To open.te the puller me­ciumisrn with II IICpara te luker, fil'1lt locale Ul!! ink"r to lhe right of the key .. r. Remove the magazine reel (123(R» (figs. I lind 2) . Thread t he tllpe on the iuker reel under tho b.,lide roller (99(H» (figs. I lind 2) , under the phototube housing (our the phototube housing in Key .. r 1'G- Io-O », undt r the guide rollcr (99(L)) (figs. I lind 2), 1.0 the hJ~ of the guide roller (99(1'» (figs. 1 lind 2), lind over the puller roller (79) (figs. I lind 2), The part of the rollcl"9 coming in oontact with tho lop, or inked lIido of the t8.pe, 1111. \'0 their ccnters recessed lind will not smear frl'Shly inked characters. The tape may fall freely into II. basket on the floor. Whf!1l us ing Keyer 'I'G-10-(2) with lin ink recorder, turn the motor switch (43) (fig. 2) ON,IIO that tht) motor is Op.:.r·1l1.OO indepmuicntiy of the rotary switch knob (105(U)) (fig. 2). If the ink recorder requiTCII an o!ICiIlator to aetllate the ink s tylus, turn tht) rota ry switch knob (105{R )) (fig. 2) to KEY, connect a manually opersl.OO key to the KEY terminals (10) (figs. 3 and 4) , and connect tht) ink rt'COr<ler sib'1UIJ inJlllt ten uinllJs to the ouqmt lemlinals (35) (figs. 3 ami 4) of the keyer.

e. Pressure roller. When the kayer is no t in UlW, ii<'t thll pressure roller (85) (figs. I and 2) up wilh the feed disengaged, to noid IlamHging t he drh'e roller (i9) (figs. I H))d 2).

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to. ADJUST ,UENTS .'OK FIELD UPKEEP. •• Tubes. A poll'

sible souroc of trouble i~ a def.dive tuoo. C hook 1111 tubt~ e,'ery 500 Iioul'll o f operation (par. ]Gf). .

b. Photoeledric cell. Should it IJecorne IIllCil8!1ary to re llIs(lfl thl' photoelectric ~II , refer to p&ragraph 16g.

c. Exciter lamp. T he exci ter lIunp (9) (figs. 3 and 4) oontains two filamenl.8, only one of \\<hich is usOO at a lime. If the lamp fai l~ to light when the rotary swiu:h ill at TAPt<:, 800 paragrallh ]6h.

d. Fuse. T he kcyer is shipped with" fnse in ]l1,,('e in il.8 ho lder (45) (figs. 3 find 4) on the rt'tH of t he challl! is. If tho keyer fa ils to operde when turnt'<i on, chock the (use. If hUM1(!(1 out, n:-plnt·(, (U!Ie

lUI outlined in paragraph ]6i. e. Operatur malntenallce. PNWl'nti\"(' mainlenanC(l I'('rfornu'(i

hy the operator is d iscltSM'(1 in pal'agraph ] 5.

" 0.'9' .11<om

UNIVE~SITY Of CALIfORNIA

Section III

Functioning of Parts

U. POWER SWITCH. Th" power switch (31) (figs. 5 and 6) is II.

thl'f!e-position rotary switch with the positiollll marked OFF, KEY, IlJld TAPE. At OI<' F the entiro unit doe!! Dot operate. The pullel moklr of Kayer TG-1Q-(2) is turned on fUld oft' independently by a morer switch (43) (fig. 2) when used lUI II t&pe puller. At KEY, the O&cillator-amplitier 8OOtion is turned on and the htmd key controJa the tone output (p&!'. lie); both the puller motor (42) (tip. 3 and 4) and the e.xciter lamp (9) (figs. 3 a.nd 4) are inoperative. At TAPE" the mooor and the ilLlllp aN! turned on, in addition to the oscillator­amplifier, and .the unit functiollll 8011 8. full automatic tape kayer .

•

1%. VOLTAGE A.MPLIFIEB (figB. 7 and 8). a. When the main switch is set a t TAPE, light falling on Tube VT~252 (phototube V,) ea\W?J!l thll Current to flow through i18 p late resiston, making the volt&ge potIitive at tho upper end of ~istor (13-1) and negative a t tho lower end of res.iJ!tor (13-2) (figs. 7 and 8). The voltage flCl'Ot!8

the bi¥ controls developed by the rootmm- bleeder clll'nlnt call3e8 a positive potential at the cathode of Tube VT-1l6 (V,) with retlpoot t.o the lower end of resistor (13-2). From the cathode of tube (Vo) to ite grid, the bias voltage is from plue to minU3, and the phototube load voltage is from minus to plU3. These two voltages are in opP'> !!ition; and the difference Cumiehee the trigger voltage, 110 that with II. greater light intonsity, the grid voltage is more positive with re­IIpect to the cath~e, and with leas light inteilliity, it is more negative.

b. Resilltor (l5-I) is the plate load for (V,) as well fUI the grid resistor for Tube VT- 116 (V,) . This tube and tube (V,) fonn a two-stage d-c amplifier. As the grid of tube (V.) bocometlsufficiently negative, there will be no plate current in tube (V.) and no voltage aeroas ita plate loRd . Tube (V,) will then have no grid bia9. When the grid bia9 of tube (V,) becomes zero (or positive with respect to ita cathode), plate current Bows through ite plate load resistor (15-1). Tube (V,) will then have a high negative biu.

t. As in the case of tube (V,), when the grid of tube (V,) becomes sufficiently negative, Tube VT- 96 (V.) will have no bias. When the grid voltage on tube (V,) tlpproaches ;&(Iro, tube (V.) will bave a high

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negative hilla, and the plate current in one section win be cut off. When the grid voltage approaches zero, the plate eu~nt !)f tube (V,) will cause a voitllg'e to be developed a.cro8II resistor (l6) in luch a direction that the upper end will be neglltive with rtlIiIpect to the lower end, which is connected to a rtlIiIiltor (27-2) (fig. 7) or (39) (tig. 8). This voltage is impressed directly ael"088 the grid and catbtv!e of t.hiI left-hand section of tube (V. ) and &ets 88 the control voltage for thia tube.

-13. OSCILlATOR (figa . 7 and 8). a. Tube (V.) is a double-triode functioning 88 a tone oecillator (of the multivibra.1or type) at a frequency of approximately 800 cycles. Thil frequency is detennined mainly by the values of the tank circuit made up of inductor (S) and capacitor (2-2). The feedback circuit, composed of capacitor (1) and refJistor (1 7), also hll.8lOme IIffect on thelrequency. Any 1Iffi811 voltage variation in the pla te circuit of the right-hand 8eCtion of tube (V.) is fed 10 the grid of the left-hand section througb capacitor (1) and resistor (17). This i8 amplified by the left-hand section and fed back 10 the grid circllit of the right-hand .eection through the capacitor (2-1). Thus energy ill fed from each !l6Ction of the tube to the other section in the proper phMII, and 08Cillation takes place. In order to keep the wave shape of the lignal from squaring, it ill neccgary to prevent too great a flow of voltagll baek to the grids. To do trul, the plate loads of each section are center-tapped at the junction of l"flIIist-01""8 (19-1 ) and 19-3) and reSistor!! (19-2) and (19-4) . The a-c retill"Illl to the. grid.!! are brought to these junction points.

b. When the light IlOllroe and tape reduce the left-hand grid voltage of tube (V.) to iero, oecillatioD takes place. No light on tube (V,) C&WIIIII the grid voltage of tube (V.) to be highly negative, which l"flIIult.s in the plate current being cut off through the left-hand section of tube (V.) 80 that there can be no oacillation .

. c. When the main control switeh is thrown to KEY, the grid of tube (V,) is connected to ground through ths key. When the key is open, the grid voltage of tube (V.) is zero an<.\ the oscillator ill inop" erative. When the key ill pressed, connecting the grid of tube (V,) 10 ground, a high negative voltage appea1""8 on it.s grid and the tube (V.) oecilla tea.

14. POWEll ~MPLl"1EB (fig!!. 7 and 8). a. The 8~ycle voltage developed &croea the tank circuit is foo &CJ"088 resistor (20), the vol­ume control. This voltage is impf"f!8scd on the grid of the left-hand section of the double-triode, phlllJe-inverter Tube VT- 96 (V.). The Bignal voltage is then amplifioo and appear!! acn'l88 the plate load resistor (22- 2); then, through ita coupling capacitor, it is impr : ssed on the grid of Tube VT- llS (V,). At the same time, the grid l"IIBistor

U

0.'9' ~11n>m UNIV[RlfTY Of CALIfORNIA

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for tube (V,) acts u a voltage divider. The portion of the voltage developed across resistor (23) is fed to the right-hand grid 'of Tube VT~96 (v..l - The output from this half of tube (V.) is fed to the grid of Tube VT- IIS (V,), Tbis producee the ne<:ooaary 180° phase difference between the signals appearing on the grid of tubO!$ (V,) and (YT) .. The voltage divider, resisoors (15-2) and (23), is properly proportioned to make these voltages equal in value. On Keyer TG-I().,J (fig. 8) resistors (36- 1) and (36-2), in seriee with the con· trol grid of tubell (v..l and (V.), act fill bigh·frequency chokee to pre-­veut par&9itic OHciI.Iationa when giIUIII tubt,i are lHIIld instead of meW tube!! in the keyer.

b. The output voltage from tubes (V.) and (V.) appe&nl &trOfIII

tranllfonner (34). The low impedance IIOCOndary of this transfonner baa a resistor connected 1I.Cr0&8 the l5--0hm output winding, in order to keep tubell (V,) and (VT) partially loaded when externa.lloadJl are removed from the keyer.

c. The rectifier circuit of Tube VT- 244 (V.) baa a resistor (29) con­nected in aeries with the load which servee to limit the peak and surge currents to capacitor EleCtion (4-3). Reeil!tor (30) iI! connected in serie!! with inductor (6), in order to provide the proper voltage for the IICreeD. grids of the output tube!! (V..l and (V,) .

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,

Sution IV

Maintenantt

Caution: Read and carefully observe the preeautions given in the .fety notice at the front of thie manual.

II. PUVENTIVEMAJNTENANCE. a. Sdtedu1ed IDipecUODL The operator should set up. regular preventivll maintenanei! lICbedule covering the poin tll listed below and any additional points needing regular atte'ntion. A check-up bu&d on thls echedule would be made daily, if the byer i8 U&ed daily. or at regular intervals, if the keysr is not UBOO. every day. Thill check-up will reduce repainl and del.y.

NOTa. Do II<>t abUM! or handle "'''Ihl,. ""Y 01 the control. nr Mmponenr. on the front ~neL

b. InspectioD JOInt&. T he check-up ehould include the fotlolll'­ing: 0) See that the exciter lamp and di&l lamp light . (2) Check the (UlI6. If a blown (OIM! i8 replaced and the new fUM! hums out, check for short circuita in the unit. Ntver ~plau a fine wiJR QM of higher fflling. (3) Impact all tube!! to &00 if filaments light. For metal tubes, touch. moilltened finger tip to the shield after the llet hu been on for • few minutes. The shield should be warm. (4) Make .a visual inspection of the unit. (Ii) Inspect all pluga, cable.. and connectol'8. (6) Keep the equipment lUI clean and 11.8 free of dUllt lUI possible. (7) See that aU roller shafts, geare, and related parts are properly lubricated at all times. For detailed instructions on lubrication see paragrapb 17. (8) See that the light aperture is clean. (9) See that tbe mirror lens is clean (par . 1611.(1». (10) See that rollere and shaft eollare are not 110 tight on the shafts that they bind, or 80 loose that they cause IlJ[c888ive weu. (11) See that all collar and roUer keya are tight .

• 1. SERVICING. •. Lenl and mirror system. (1) Clean the exposed side of each lens (60) (figs. 3 and 4) daily with a 80ft cloth or clealUlIDg tmue .

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Caution: Do not use a tissue, cloth, or allY material t.hat 0011-

taiM dirt, grit, or any abrasive or the lens surface will be !!Cratehed. (2) At l6a8t ollce a week, remove the mirror housing C8.8ting (62) (figs. J and 2), and clean the mirror lenB. (3) Remove the phototube cover (59) (figs. I and 2) once a week and clean the light aperture carefully with a piece of fine wire to remove any accumulation of grit or lint. (4) The poei tion of the leUB and mirror housing ill adjustable to per­mit positioning the light beam on the small aperture in the phototuhi! cover (59) (figs. I, 2, 5, and 6). By turning the lower screw (165) (figs. 5 and 6) on the housing, which is provided with a spring tension holding arrangement, the housing may be moved away from, or brought closer to the panel. L&teral adjustment of the lens and mirror housing i8 obtained by loosening the upper screw, moving the housing to the dllllired position, and retightening the !!Crew.

b_ BrITe eone aad roUer. A supply of neoprene rings is included in the spare parta kit. To replaoo the rings--(I) Release the setecrew in the. collar. (2) Remove the puller-e.haft retaining collar (72) (fig. 4) 1\8 follows: grasp the taporpuller roller (79) (figs. ] and 2) and pull the Bhaft forward. This releaB611 the cone-ddven roller uBernbly, which is keyed to the $haft. . (3) To remove and replace the neoprene ring on Keyer TG-IO--(2), remove the nut and outer wMher of the cone-driven roller a88embly. Afur the shaft of Keyer TG-IO--(l ) has hi!en pulled forward , the old neoprene ring can hi! rolled off il8 metal pulley and the new one installed. (4) In reB86l!mbling, be sure to set up the retaining collar (72) (fig. 4) 90 that 6JlC68S end play of the puller shaft is prevented; but he eure that this adjustment is not tight anough w cause binding. (5) About ouce a month clean the neoprene ring (77) (figs. 3 and 4) and the driving cone (74) (fig. 4) with hi!nzene and a soft cloth to remove any oily film which may ha\'e aceumulated. Do!W!-rue oo~, wu.cII. a8 .ronapapu, on IN drimng ~.

c. Puller roller: A supply of puller rollers (79) (figs. I and 2) ie included in tba spara parte group. To replace tbe rubher portion, remove the acorn nut on tbe front of the roller and take off the outer washer . Remove the rubhi!r puller , install a now one, and raassemble.

d _ Tra n sror mers. Oue epare transformer of each type required by Keyer TG-lO- (&) is included in the spate parts group.

e. AmpUfter . Figures 7 and 8 are circuit diagrams of the amplifier and OIICiIlator. Tbe same diagram is at.tached to the bottom plu!! of the chaaais. Paragraphs 18, 19, and 20 give the nece86ary infonlla­tion for checking and servicing th~ amplifier.

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r. Tubes. Tubal! in the keyer may be checked in a standard tube te8tet. Replaee all defective tubell.

,. Pbotoeleetrlc OO!. To replace the photoelectric ceU (V,) (figs. 7 and 8), fint loosen the knurled nut (165) (figs . :; and 6) under the protruding housing and, remove the housing covor (59) (figs. :; and 6). Replace tube and hOUSing cover.

b. ExcIter lamp. The exciter lamp (9) (figs. 3 and 4) containe two filamenUi. To chllnge from ODe filament to the other, first remove the bulb from its eocket lind then reinaert it afUlr turning it through 1800 or hallway around. This will connect the spare filament. II both fillWlenUi are burned out, replace the bulb. II DO apare exciter lamps arc available, replace it with a st.a.ndard 32- 32 candlepower,

. No. 1000 automobile headlight bulb. To adjust the focUII of the light beam, looseD the two screws holding the exciter lamp 8OCket, move the lamp Il.D.d socket to the optimum position, Il.D.d retighten the two !!Crews.

I. Fuse. To check the fWlO locsted st t.he rear of the cha.ssis, uo­!!CrBW the red portion of the fWlO holder (45) (figs. 3 Il.D.d 4) with 8.

!!Crew driver. The fuse will come out with the screw cap. II it is defective, insert a new one. If fU8(!t. are not available from spare stock, the keyar may be fusod witb a standard 3AG automotive fuse baying a rating of 3 a.mper68 at 250 volts.

"

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18. ~UBLE LOCATION CU .... T ••• TAPE po81Uoo. Symp­toDlll (I), (2), and (3) below apply when the amplifier, exciter lamp, or motor are completely dead. If thll amplifillr is appare.lltiy ON and thll eJ.:citar lamp awl motor Op8ft.te, but no signal is recBived from the keylU', look for tbll f'AIll"ining IIYIIlptoIIlB, b(l ) to (11), inclusive, below. Tubtl (VI) (figa. 7 and 8) will light and lOme heat will be radiated by the other tube., IlIIpecially tube. (V.) (figa. 7 and 8) and (V,) (figs. 7 and 8) , if the amplifiar is dra,wing power, even though it is not working properly. ,

SV"'""",, Co"", (I) Amplifier dead, e:a:- No IL-Clline volt&gl.l. citer lamp O.l<'F, motor Open power lead. not nmning. P oor plug (11) (lip. 3 and 4) contact.

(2) Exciter lamp not lighted, motor runa, amplifier ON.

Burned-out fuse (par. 16i). Defective power lIWitch (31) (figa. 5 and 6). Loose ooIlllection from power receptacle (1 1)

(figa. 5 and 6) to fuse holder (45) (tip. 3 and 4), to switch (31 ) (tigs. [) and 6), to tranefonnen (32) and (33) (figs. 5 and 6) and receptable (12) (tip. 5 and 6).

Burned out e:a:citar lamp (9) (figs. 3 and 4) . Loose oonnection or defective lOCket for

exciter la.mp (9) (figs . 3 and 4) . . Defective power switch (3 1) (figs. 5 and 6). l.oo8e connection on power switch (3 1) (tip.

Sand 6). Defective e:a:eitar lamp tr8.n6former (32)

(fip. 5 and 6). Loose connection from power 8wik:h (31)

(lip. S and 6) to tl"ailllfonner (32) (figs. 5 and 6) to !lOCket of e:a:citer l.a.mp (9) (figs. 3 and 4) .

(3) ).{otor dead, exciter Defective motor receptacle (12) (ligs. 5 and lamp and amplifier ON. 6) or plug.

Defective motor receptacle (12) {fig. 6} or plug (41 ) (fig. 4) .

LoosII connection from power 8wit(:h (3l) to motor receptacle (12) (figs. 5 and 6) .

Loose connection from motor plug (41) (fig. 4) to switch (43) (fig. 2), to motor (42) (fig. 4) on Keyer TG-IQ-(2).

Defective motor (42) (figs. 3 and 4). b. KEY posItloo---key termloals shorted. For check of the

operation of th~ amplifier alone, it is efl8ier to start with the switch set at KEY position, since tWa narrows the preliminary search to t.hll

0.'9' ~11n>m UNIV[RlfTY Of CALIfORNIA

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oscillator a.nd power amplifier. Th_ components are common to both KEY and TAPE opel'lt.tion. Test all tubes on a s tandard tube chooker before starting on a cirouit lWaly.ia.

s~ ... piom

(1) No filament volt­.... (2) No pIau or screen voltage 01} tubes (V.) and (V?) (figs. 7 and 8) .

(3) Higb plate and screen voltage tubes (V.) and (V?) (figs. 7 and 8). (4) Low plate and screen voltage tubes (V.) and (V?) (figs. 7 and 8).

(5) Low or no plate voltage tube (V,) (figs. 7 and 8) .

•

Defective power transformer (33) (figs. 5 and 6) .

Loose connection from power tr&.Illlformer (33) (figs. 5 and 6) to tuoo lIOCkete.

Burned-out rectifier tube. Open res.iator (29) (figs. 5 and 6). Open filter choke (6) (figs. 3 and 4) (no

screen voltage). -Shorted filter e&.pacitor (4- 3) (figs. 7 and 8)

or (4-4) (figs. 7 and 8). Loose oonnection or open lead from rectifier

tube (V.) (figs. 7 and 8) to re9istor (29) (figs. 5 and 6) to output transformer (34) (figs. 3 and 4), to pla tes of tubes (V.) and (V,) (figs. 7 and 8); or from resistor (29) (figs. 5 IWd 6) to filter choke (6) (figs. 3 and 4), to reBistor (36) (on Keyer TG­Io-J) , to IICTOODS of tubes (V.) and (V,) (figs. 7 and 8).

Open primary of output traDllformer (34) (figs.3and4).

Open resiBwr (24) (fig. II ) . Open lead or loose oonneetion from re9istor

(24) (fig. 11) to tube 8OOkct.

Shorted resistor (24) {lig. IlJ. Shorted capacitor (4- 2) (figs. 7 and 8). Shorted grid reaistor (15-2) or (15-3) (fig.

11). Shorted coupling capacitor (3- 2) or (3- 3)

(fig. 11) . Open lead or loose connepion from re9istor

(15-2), (15-3), or (23) (fig. 11) to tube socket or ground .

Defective or open resistor (22- 1) or·(22- 2) (fig. 11).

Defective or open r(lllistor (23) (lig. 11 ). Defective resistor (21) (fig. 11). Loose connection or open lead from resistor

(2Q) (liB". 5 and 6), (22- 1), or (22- 2) (lig. 11 ) to tube soeket.

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S,"'P'<>'" (6) High plate voltage tube (VI) (figs. 7 and 8). (7) Lo ... or no plate voltage tube (V.) (figs. 7 and 8). (8) High plate voltage tube (V.) (figs. 7 and 8) . (9) No audio frequency output.

(1 0) A-<: ri pplf in out­put.

( II ) Low audio fre-qu .. ney output.

Co_

Open I : Iistor (21 ) (fig. II ) . I..oo&a connection or open lE'ad from l'I:'$ietor

(21 ) (fig. II ) W tube socke t or ground. -Defective or open ree.iewr (19-1 ), (19-2),

(l9-31, or(l9-4) (6g.11 ), Defeetive resistor (28) (fig. 11). Open reBiawr (18) (fig . II) . Looee connection or open lead from re8il1tor

(18) to tube BOCket or ground. Head&et plug not completely llilerted in

jr.elr.: (8) (figs. 1 and 2). Defective headlll'lt , bea.d5et plug, or headset

00«1. Loose OOD.llectioIlll from transformer (34)

(flg.. 3 IUld 4) or jack (8) (fige. I and 2) to tenninlli lltrip (35) (figs . 3 and 4).

Defect ive IIOOOndary on output trall8fOnDeT (34) ffigI. 3 and 4) .

Sborwd external leadll from tenninal amp (35) (figs. 3 and 4).

Damaged capaci tor (2-2) (tip. 5 and 6), O J (fig. 11), or (3-1 ) (fig. Il l,

D efeetive or damaged ll'l8iator (IS) or (17) (fig. 11),

Defective or damaged OIICillator choke (5) (figs. 3 and 4).

Defective filter choke (6) (figB. 3 and 4) . Defective filter capacitor (f.-3), (4-4), (4- 2),

or (4- 1) (figi'. 7 and 8). D .. r(!ctive tuoo (V.). (VI). (VO). Of (VT),

(figs. 7 and 8) . Defective output tr&n6fonner (34) (figi'. 3

and 4). Shorted external leads from terminal strip

(35 ) (6gB. 3 and 4) . Shorted or damaged resiBtor (Ui) (figs. 7 and

8) . OPlln or defective resistor (23) (fig. 11 ). Open or damaged capacitor (3--1), (3- 2) . or

(3-3) (fig . 11). . l.ooBe connectiolllllrom any of the8(\ part8.

c. TA.PE position- tape operatl0l. Aft .. r the troubll'Jll indi­cated by symptoms ( I ) to (3) in a above and (I) to (11 ) inclU$ive in

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b above have been COlTOOted, check opllJ'&tion at TAPE ae folloW1l: satisfacwry operation at KEY and no operation at TAPE limite the trouble t.o tubell (V,), (V,), and (V.) (figs. 7 and 8), and their ~ ciated mechanical and electrical parte. Make these teBUI only after it has been definitely aMured that the phowtube aperture, lem and mirror, controls, ek:., are set according t.o the operation instructions in paragraph 9. The point-to-point resistance check IIhouid indicate nil probable defecte.

S~mplom

( I) No plate voltagr tubell (V. and V,) (figs. 7 and 8).

(2) No keyi~ with "'p'.

""_ Shorted capacitor (4-1) (figs. 7 and 8) . Open resist.or(27- 1) « 27- 2) (fig. II ) on

Keyer TG-1O--(I », (27) « 39) (fig. 11 ) on Keyer T{}-lo-(2», {(26) (figs. 7 and 8), or ("O) (fig. 8) (not on Keyer TG-Io-(l».

Loo&e oonnection to tube aooket. Open resistor (13- 1) or (13-2) (figs. 7 and

8) . Resistor (13-1) or (13-2) lIhorted to weld

ground (figs . 7 and 8). Looee connection to tube aookl!t.

1'. POINT-TO-POINT D-C VOLTAGES. The tube aooket pins from which the meuuremente shown in the follOwing table are made are identified hy numbel'll appearing on the botwm of the aookeUl. The readinga are taken with line voltage of 115 ~olte; both bias con­trol8 at extreme right; volume control advanced one-ball of ita wtal rotation ; main IIwitch turnl"d alternately from KEY w TAPE, as noted ; photocell adjustable cover in normal operating position with­out paper tape or other Bubteance inten'upting light beam; and with nothing connected to OUTPUT terminalB or KEY terminals. The location of the tubel! from the botwm of the ehaseia is shown in figure$ 9 and 10 where they are identified by the type and tube number. The following readings should be ehecked with a 2O,OOO-ohm-per-volt meter only.

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- .... (Vil. __________ • VT- 2S:l •••• • __ ••••• (vil ____ ...•• _._ VT- 2,)2 ••.••••• •••• (v.}.. _ ••••• • • •• VT_11II •••• _______ •

(v. ) ........•..• VT- I III. _____ . ____ • (VI) ___ ••••• ____ VT- IIII .....•...... ( va} ••.••• ___ ••• Vir- IIG •••••••.••.• (VJ •.•••••• __ •• VT- M ••••••.•••••• eVil ............ VT· II6. ____ ._ • _____ (V. ) ____________ VT- M _____ __ ______ (VJ _ __________ _ VT- M ____ ._. _ •• ___ (V,) •• ____ • • ____ VT- M ._ • • _._._ •• • _ (V,) ______ • ___ . _ VT-M _____________ (V,) . ________ ___ VT- ge ________ __ ___ (V,) ______ _____ , VT-M __ • ___ ._._ . _. (V,) _____ ._._ ••• VT- 116 • • •• • •••••• _ (V,) •• _ •• • •••••• VT- 115 ••••• _ •••••• (V. ) ....... _ .. _. VT- 1I6 •• _._ ••• _ •• _ (v.) ___ •• _ •••• • • VT- 1I6. __ •• _. __ ••• (Vol _ _ •• __ •• _._. VT- 244 • • _ • •••••• _. E~ell.o!tr l-.mp_ • ••••••••• _ • ••••••• • __ ._

·OD _""_Io.

- - -.

, .. PI!: , -- --- ••• - .-

4-CDO __ • ____ •• • ___

" --_._ . ------4-CD._ . • ______ ____

" -_. -- _. _.-&-~--.-.-.- -- . -. - -. .M H .. 8-6 •• _______ _______ , ,., , .. 8-6 _____ _____ ______ .. ,., •• 8-6 ________ __ . ____ _

"' H .. &-a. __ _ •••••••• __ . " ... , .. 8-3 .. . _____ _______ _

'" 2- ; .. &-e _____ ___________ .. 2-, .. 8-8. ___ __ ____ _____ _

" ... , .. &-3. _. ___ _______ ___

'" 2-> .. &-3_. _______ . ____ . _ ". ,., .. 8-8 ______ . ____ _____ . 1.50 ,., .. 8-8---.----- - --- ---1 1M 2-, .. &-3 ... _ •. _ ....... _. 370 ,., .. &-3 ••• _. __ •• • • • _ •• _ '" ,." .. 8-3. _. _____ ._. ___ .• 370 ,., 1 .. &-3. __ ___ _____ •• _. __ 862 2-, .. Pl&l.o!tto pt.'"" •••••• _ 7.50 ... ..

----. --. -----------·1- -.. -. -- .. --- ..

. ""'>,,, - 1,..",",_

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---- --- .. -----. ... _ .. ..... - x ----- , -- ----_ . .. -.... -...... . . -. -. ... . _. X

>-GO " ... " x ------.. GO .. ... '" o.-' ". X >-GO .. ... .. X -_ .. _ . ..aD " ... " -- --- - X .. , , .. ----_. ------ X -_ . . . -.. , ". ------ ------ ------ X .. , , .. X

. ------ -.-.-- ----. . .. , '" .. ---- ._. _-- --- --- X .. , .. -_._.- ------I x -----.., .. ------ ---- --,--_._- X .. , .. ------ ------ X .. -_ .. .. , .. ---- -. ------ -- -.-- X .. , " ... ." X . ... -. .. , " ... '" _ ... . - x .. , " ... '" X .. --_. .. , " ... 275 ______ X

• -_ .. -... -....... .. _ .. -............ .. .. -. ._-..... . .... ... .. .. _- ••• _ •• 1 •••••• ..... -

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28. POINT-TO-POINT RESISTANCES. a. Resistance In ohms from socket contacts to cbassls. The tube IIOCket pins [rom which the measurements shown in the following table@ are made are iden­tified by numben a.ppea.ring on the botI.Qm of the IIOCkets. The con­ditions for taking thll8e measurements a.re that: the plug be discon­nected from the power source, both bias oontrols at extreme left, the volume control be rotated I.Q extreme right; snd the main switch a.t TAPE. The location of the tubes from the bottom of the mll.SSis is shown ~ figure@ 9 and iO where they a.re identified by type and tube Dumber.

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(V ,) ..•. ____________ VT-252 .. ____ __ • • ____ - - - - .w m"l!. --------_ . 5, 700 (V,) ___ __ • __ .•••• __ ._ VT-JIII .• ___ • __ • ____ _ , 5, 700 >. 00<> ~O meg. ( V,) ____ __ _____ __ ___ _ VT- I 16. _______ . _____ , 5, 700 t., 700 275,000 (V,). ____ .• _ .• __ ___ _ _ VT- IIS. ____ • _________ , 6, 700 71), 400 78, 400 (V.) _ .. _ .. __ . _ .• ___ . J VT-96 __ ___ __________ , 6, 700 116,400 ..,. <>00 (V.}. ____ •.. __ ...... : VT- IU. _____ _____ __ _ , 6, 700 ". "'" 16,400 (V,) ____ _____ __ . __ . __ , VT- \ 16. ____________ _ , 5, 700 20. 400 16, 400

T G-IO-D, F, G, H, AND J , •

(V,) . __ . _._ . _. ______ _ VT- 2f>2 . _______ _____ • - - -- 4{) meg. -_ . . . _---- '. roo (V,) . _____ . ____ • ____ • VT- 118 . _ •. __ . _. __ . _. , •. roo '. "'" 40 m"fl;. (VOl ___ • _ ••• • • _______ VT- 116. __ . __ . _______ , '. roo • '00 "". 00<> (V.) . ____ • ____ __ ••.• _ VT- 96 . • . •. ___ ._. ___ . , 3, 700

'. <>00 78, 000

(V,l _____ • _____ • _ . _._ VT- 96. __ ___ _________ ~ , 3, 700 lit;, 000 000. 00<> (V.) •••• ___ .......... VT-115 . , ________ . __ . 1 ,

• '00 "' <>00 18,000

(V,) . _. ___ • __ __ .. _._. VT-115 . __ . _. ____ ... _ , , 3,700 ",000 18, 000

,,, .. - _. --_.

, •

---------- ._----- -- ->. <>00 275, 000 5, 700 78,400 6,400 10,400 9, 100 116,400

"'. 00<> (') 270, 000 (-)

,

----- ----- ---_ .. _--->. "'" ' . roo • '00 '. '"" '''''' n. <>00 9, 100 115, 000

"'.00<> m . <>00 "'.00<> '270,000

-------_ .. "----_ .. ::;, 700 ::;, 700 ,"00 "', 700 5, 700 1>,700

-- --------,,00

'. '"" 3, 700 3, 700 3, 700 8,700

"'. ,. '. >.

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"'" ;70

'"" '" '"

--.. .. "". 00<>

" 00<>

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b. Resistance from restsror aDd capacltor mouDtlDI card terminals to chassis. The t.enninal.$ of the re!!U1wr end cap&eiwr mounting e&rd (38), from which mellSurement6 of rel!istanee to ehaaais are made, are identified by color coding (figs. 9 and 10). - Resistance meaallffmcnUi from these terminals to chassis are indicated below in the order in which the terminals appear when the bottom of the keyer is viewed with the front toward the observer (f!%eept on Keyer TO-10-(1). The conditione for taking these melUlurement6 are that the plug be di&::onneeted from the power llOUrce, both biaa controls be at extreme left, the volume control be rotllted W extreme rigbt, and the main IIwitch at TAPE.

W"" 001<0- _ • , , ...... w ,," __ .:.::::r;::"," "'-'(obmo) oil 5 rob",," .

Black ... _ ................... , yell .... _ ...... '" Green .. _ ................... _ ""', 000 _ ........... _. llO. 000 BI'O ... n ......... _ .... _ ...... . " ... . ._ ..... . ..... , Blue • ••.•• • _ ••• . _ • ••• •• •••.• 115, 000 O ..... n .. ..... . """, 000 ..... . . _ ...... _ . . ........... 116, 000 Red .......... ,,000 y ellow .. .... _ .. __ .. _ ....... . >,000 . ,

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

0_0 ..... . _ ..... ........... S, .. BI...., ......... . .w. 000 Blue .... _ ................... ,", 000 .............. '" 000 BI'O .. n .. . .......... ... ...... 72,000 ... .. _ .... .. .. ,,000 ~ .. . . . . . - .......•... - ... . '. 000 .. _ .. .... _ .. . - .'" 000 y ellow .. ................... . • .. G ..... o ... _ .... 7, .. BI'O"'o .. _ ... _ ... _ ..... ....... " ". yello ...... .. . > , ,ro Oreeo ..... __ _ ............... "', 000 . ..... _ .... . .. " '00

%I. INSTRUCTIONS FOil FUNGIPROOFING AND MOIS­TUREPROOllNG_ The instructions contained herein are" guide for processing Keyer To-to-(&}.

a. UIllICrew and remove the six screws and washers holding the front plUlel to the cue.

b. Turn the unit over on -its side and remove the three screws, nuts, and wll8hers holding the chassis w the bottom of the case.

c. Tum the unit to original po!Iition and slide the ehlUlBis out of the ,~.

d. With a elean cloth; remove all dirt, dust, and rust or cOlTO!lion, from the eaee and eh&8Sis.

e. Remove the following tuhet! from ehassU!:

2 Tube!! VT-1I6. __ _ . ___ _ 1 Photocell (RCA 923). 2 Tubllll VT-9~1.. __ .. _. __ I Tube 5U40. 2 Tubea VT-115 ___ . __ . __ 1 Exciter lamp (Muda No. 1000).

0.'9' ~11n>m UNI V[RlfTY Of CALIfORNIA

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r. With mAsking tape, oover--­(I) Nine tube sockeUi (lop). (2) [MR of exciter lamp, rear and front of panel. (3) Around b&llE! of motor plug and socket. (4) All vent holllII around wp, sidllll, and bottom of mowr. (6) OilholllII and ahafUi in all ge&I"Il ud bearinga. (6) Neoprene ring for drive roller. (7) Batt<:lry connector lugs (at rear).

·C. Tum the ebnejs on iUi side and remove the four screW!! bolding the panel bBINI to the ch .. · j· Remove the panel.

h. Untie tbe lacing from the cable fonn ud allow the wiJ"8, to hug lOOf!e.

I. With mllBking tape, cover the jack contact and jack collar. J. Loosen the knurled nut at the bue of the photocell tube oover

and remove coyer. Maak the !lOCket with tape.

k. The unit is now ready for baking. P lace the component!! in a heating app&ratua and bake at a temperature of 160" F. Do f10t ucud tAu temperatuTe. Bake !.be unit for approximately 3 houn. Watch for indications of melted WH ; if thill OOcomllll evident, lower the baking temperature, adding 1 hour w the baking time for 6ach to" F. drop.

I. After baking, remove the oomponentll of the unit from beating app~rat\l$ and apply varnish to &II parts and exposed metal with a p&int brush or spTay. Follow the instructions provided with the kit.

m. After the varnillh has been applied, replaoo the unit in the heating apparatus ud allow it to remain there for approximAtely 30 minutes until the varnish has dried.

D. Remove the unit from the heating apparatue and repeat the application of varnish. Replace it in the heating apparatus. Shut off heat and allow unit 10 0001 for appro:nrnately 12 hOIlnl. When the unit h8.11 returned to normal temperature and varnish is absolutely dry (not tacky), remove &II masking tape.

o. Clean off any exOO86 varnish on those portions where it will impede electrical continuity or mechanic&l scuon. Extreme caution should be taken when varnishing around moving parUi, as varnish, whell dry, will impede the mechanical motiOIl.

p. UPOIl completioll of baking, remove the unit and spray three or four 0011.1.8 of v&n,ish on exposed element!! and iuri!l.CllII. Do not spray fIVnt panel of uni t . Spuy the inside of the ease. Wbetl var· nish has dried, remove muking tape.

q. Replace all parUi removed; oil al[ sbaft!!, geartl, and bearing!'-Check the unit when assembled and mark it MFP ____ (dat.e), __ • ___ _ w show it has been fungi proofed and Illoiatureproofed . ..

Or'9on.rln>m UNIV[RlfTY Of CALIfORNIA

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• Sedion V Supplementary Data

n. TA.BLE 010' REPLACEABLE PA.RTS. -

I\< ~ , .. " ~_c_ , .. " ' ..... Sa. _N ..

, 3 1~7~ ._. _. c..-hor._ ... O,ooos. .. I , :i: 10 pe_,,~ 300-v d..., ABCD' .. orkinl , 11468. FGIlJ ~ , 31)11.100-0 ••••• C"P&c!\OI _ ••• _ 0.1 . .. 1, .... pe,..,.nt - IO peroellt. ABCD 2(IO.v d-e worldn«, ,,",per, luOOI ..... ~'G HJ ~, 30 11.1 00-47. ___ _ Capacitor . _ • _ • 0,1 ___ ' , + 40 """",nl-]O per"'ml, ABCD IlOO- v d-e wo.kln!!. P&pe., tubular, FO IIJ "-, 3 011.10-149 C.p .. dtor . ___ . 0.01 .... 1. +.0 »eroen i - l0 perceM, ABCD ...... ,< .. orklng p.p et, . 'OIlJ ,n-.:il&-E, 3-Z, 3 3 011.10-1.3 • .••. c.p.,,!tor _. ___ 0.01 ... 1, + 40 peroe nt - IO P'l. cent, ABCD 60(}.. ... d-e wo.kl"8. p*per, W hit] •• , FGIIJ '27302.

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h_ Moo,' "",, M_II"" " ""'_Ne. -Qo.:malOr feed t-k. A • • _____ ___ , '","

o..:m.1ol f~~L .... -........ " ',," OtelU"tor tank ., ___ • --._---- --- -- " "I'

let audio Irk! eou- Si3nlll Corpo. , pUn. , Ip~c lfie._

tlon •. 2d .,,<110 ,rid oou- fn', ... _ ..• __ " '",' pll",.

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ABCD FO HJ

, 3CZ513 ______ __ .I COi!. _____ ___ .

ABCD FOHJ

Fou..-etion al uminum can. 10-10-10-1 0-~f. + «1 pet<)en~-jO per per«nt. 450-v d..., "'ortinll', rlry, et<tetrolyde. ,FPQ-4:U.

T&nt. 450-mh. air core. I T ...... Il005 . __

FiLter ___ _____ _ ~ ___ 1 MA ________ _

Ooc:mator tank _. __ '! TH ________ _

, 3C316-22 ______ .I COil ______ ___ .I 0 h at 80 rna. iMn (':Ore. tropical treat- 1 Filt.". ehoke _____ __ I TH ________ _

ABCD men\ and .pecial 1~1Od len~U"" ~'OHJ IT ...... 8008. , 3Z2603. 2 ___ ___ _ 1 Fuoe ____ _____ -I 3-amp, 250-v. gl .... lUbe. type 'HK8_1 Llne ___ ________ ___ 1 LF ________ _

ABCD FOIIJ , ABCD FOIIJ

, ABCD FOIIJ

" ABeD ~'OHJ

" ABCD FOHJ

2U5119 ____ ____ .1 Jack _________ .! Monitor . 2-<:ontact, in."lated. OpeD

circuit. 3".' long. II. including e:.trude<! fiber ... MlIe, '203, bake­lite ..... her '212. br .... .... her In5, ,'-32 nut '232.

6Z61lO6 _____ ___ .I r...tnp ____ _____ I 6- to S-v. 3:Hlp (2-filament ). bayouet

baIIe. ~h .• da.

2ZIH63. 1 ____ __ .1 Terminal . __ . __ I 2-oontacl, fiber_mounted . .. ,ew type. '2--50.

2Z713& 1. _____ .1 Receptaeh: _____ 1 2-pole, /lu.h, male, ljof " diameter. ,6HIlO.

, kU<n lad ...... _'" 10 wblob pot' oppJlH. , 800 par. Jan ""~Inp or .. , ..... ' I .... ~t. Elt. w ...... -. SolI . ......... m7l1. I ... ......... nmf. Nu. n llG.

Monitor _________ __ 1 M- y ______ _

Phototllbe ~~eiter __ ! OE ________ _ , Key ____ __ __ _____ .] HJB _______ _

A- e lupply--- --- --i HM _______ _

" ... 27293

"'" 27323

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~ %2. TABLE OF REPLACEABLE P"'&TS-Contlnued. ._- 8\n., ('orpo ,- 0-."', .... "- _N •.

" 2Z8681 I ... __ ._ 8oo1<et. • • __ _ • • Female, 4-eont&e~ mjnlAt~ polar. ABC lud eh"";. m"un~inl . ~ .. diam-

101. .... , '848.

" 2ZSG84. _._. ____ 8ooket. . ____ • .- Fem.le, '848 . . ___ . .. . . . __ .. . • _ . . _

DYGDJ 13-1, 2 3Z6820. ___ • • __ • Remol.or _. _____ -'"". .., pwoellt, .... ABeD carbon, 'BT-~. !'OHJ .. 3UilXli L . u __ ReI<is&or __ •••• _ ... 7-obm, ± 10 peioent, 1-., wire-ABe D ..:Iund,IBW- I. • • FGIIJ ,~ , 37.6777.. •..•• _. ... ~, 270,000-01110 , . ::I: 10 .....~. .... ABeD carbon, 'BT-}O. FOBJ 16-2, 3 3U172'L ____ ___ RM1.qor ... ____ 270,OOO-ohm, ::I: 10 ..... LEDt, .... ABeD carbon , 'BT- loS. FORJ

" 3Z61168 • • __ •• __ _ RMlltOr ••. ____ &8,OOO-obm, ±>O patEL!., ....

AB CD carbon,IBT- }i. FOHJ •

" 3Z673~1 ••• •• •• Reo.iotor ••••.•• 8g(),OOO-<>Iun, ±10 pe, ...... ~, .... ABCD carbon, fBT-J' . FOHJ

" 3Z&047-3 •••••• _ R ... I .............. . f70-0Iun, ± 10 per ...... t, 1._, earl>on, ABCD IBW- t. FOR' •

~- 101....,' ...... w __ d,w._, ,~

Motor _ket. __ ___ ------- ---.-. " " .

Moto • ...,kel. •• ___ AM. ________

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Phototube Iotwi. ____ IRC._ . . ____ " '"

Setle. tll&m~ot , lorr. IRC. _____ ._ " '" d.., ..."pliJIer.

2dd-oJTkI ••• . ___ _ IRC __ • ••• _ • " , 2d audio srid !'ell;' IRO ______ ._

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2Zge.aZ.Z5 ______ 1 Tran.lonn~r ___ 1 Output pri. 8,OQO-ohm C. T . ..,.,. 0-, OUtput ____________ 1 TH. _______ _

0&-, 8-. and l~hm, tropical t ..... t-men! .... ith .peei"lleo.d., ,T-I6004,

'2Z!H04.2. _____ .I TerminaL _. __ .I "-ooot..,t, 6be._rnount.ed , ..,.., .. type, I Output. ________ __ .1 BBJ. _____ ~_

14-50.

3Z602~3 ______ .1 ReAioto.," ____ __ 1 '2W-ohm. ± 10 percent, * .. , cubon,

-iA 1200A/406. __ I Moullting cartL

~," dl&meter, "I," long. 1ST-So

B&l<elito: card iDcluding ooldering I~. ...,d mounting .tudo, .peelal.

Ou tput tube •. pa. ..... . !tie oleHl"lion . UPP...,IIIIO • .

~.toT ."d eapa<l-

1(.0' mountlng.

UlO. ______ _

31.6400-3. _____ .I Re3;"tor ____ ~ _.I 4,OOO-ohm, :I: 10 percent, 2-... ,BT - 2 _I VoltaV' div ider ___ __ I IRC •• _____ _

ZZ7287.2 ___ ___ .I Potentiomete • .l200-0hm, 2- .. , U_. taper, ... 1* I Vern!erb .... ______ .I IRC _______ _ wound. with m<>i.tu ... oea! and ope-ela! .haft length. 11." diameter. 1:2181.

2Z7138.2 ____ ___ I PIUH __________ I Male. S-oontact ___ _____ __ _____ . __ .I Motor c<>n"eeUou _.I A M ___ _____ _

2Z7234-6 ______ .1 P IU B __________ 1 ~ntaet. polarited •• hlelded. mlnia- 1 Motor oonneetion __ .1 AM ________ _

tu .... 'MP48. SH3000-I.'- __ __ 1 Motor _______ .1 I [{I_v , 25-c:ye!e. ' CX-2 1321L ____ ___ I Tapo drive ____ ___ .! 0 1. _______ _ _

8USOOO-L ____ .1 Motor _______ .1 1100v, 6O-eycle. 'CX- 21325 ___ ______ I Tapo drive ____ ____ 1 Gr. ___ _____ _

SU3000-3 _____ .! Motor _______ .! ll .s-v, 6O-eyele, O.6»mp •• haded I Tapo drive _______ .1 01. ______ __ _

p<>1e. ph<>nograph-reoording motor. 0 1 type, RX with opeelal alW't, '23028.

•

27291

27336

Z'7748P

,., .. Z'773 l

Z'77SS

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2769"1

Z'7Il S

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tI n. TABLE OF REPlACEABLE PA&TS-ConUnued. --- 8 ...... C""PI No_ -~-••• """. r<o. . .. 3ZlIS5S-li. _. ____ S.n'ch . . .... .. Motor, doubl&-po~, fIln,le- t hrow

OFOHJ togl~. .. 2Z~ __ _ ._. ___ Lamp ______ ___ 120-¥, -l- .. . candelabra bNe, m;ni ... ABe D ture bulb, Mud.& 11000. FGIIJ .. 3Z321S._. ______ rILle pOIt ______ 81aet W,kellt.e, 2,," long . lot " ."" .lIlt-. ABe D ill, bole, IncludM poot , n tnw:wr, FGRJ nut . and wa&b~r. '1076. . ., (AI200D/7UI. •• R_ tor _m_ l "cl!l1lM t .. " 2O-megnhm, I'-w ....... OVOII) '''. ton (13--1) ouut (13--2) , brMO Ihleld

tube 2W' long . b .... I ltield lube '"'' long. plLo,ic InouJat.l"ll be&de, .- . ., 6Z8368. ______ __ -SOCket . _______ MeuJ-lIanp<t. doubLe-oontact, !).ay-

ABe D o .... t ty P". with .older terminal .. FOIIJ 112. .. 228162.2 ••••••• Soc"' . .... ... ThO.. 8-pronS. -". 8-oont_. AB CD . retai .......... ;n!!: mounti .. g. mi.,.. FOIIJ • filled . for ~,." Atoek . 188-8.

'" 2Z865H .•• •••• SOCk~ •••• • ••• 4-oo .. !.&ct . _al".". •• !", mountinR. ABCD Steatitto. fSS4. FORJ

" 2ZMlSS-lfI • ...• • SOCks __ , _ •••• Candelabra tyP". ilUlulated .loned DFGH J bruket . bent do ...... UI4L--CH.

" 4A \200D/1 If1 •• • Reulneo- ring •• I"," OD ~ , .. 10 • ~." .Woel DFGHJ ..... her. , ...... !wIM 1&-82 • .---

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sist.". _mbly. •

F.~cit.!r lamp ___ ____ M. _________ 7 I

V...,uum tu~ •.•••• AM •••• •• _ • • , , PhOtol.ube ••••••.•• AM ••••••• •• 7 ". Di~ ~p ••• . •• • •• D • ••••. • ••• 7 .,

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4/o.1200DIUO. __ 1 AMembly _____ _

4A1200A/ IM ___ 1 Roller _______ •

~"diameter s '.14," long, br ...... ope­~I.I.

p,." .. "re roller, L"." I >1" I \l," oheet .teel. inch"I ... arm .t...ft and pl"eMure roller stud, lpeeilO.l.

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4/o.I200D/M6 __ .1 RoUe. _____ ___ .1 P ...... " ..... peelal ______ _______ ___ .. _1 Tape contaet p"",.

4/o.1200DI:;45 __ .1 c.m _mbIY _II" diameter I M.", .h""t .teel,_ oembled to hub, .pedal ,

4/0. I200 DI MO. __ I a ..... ket ...... m· Speed C<lnt rol. inelud"" ;UdieRtOT dial bl.... bearing, ol>OOiOl.l.

4AI2000f5M. _.1 Feed oere'" __ • • __ •• _ . _,',". ___ "" __ • __ . _____ _ .

4A I200D/62:L _ J Collar _~ ___ ___ _

4AI200.4./IM yoke ____ ~ __ ._

fA 1200D/ 5f15 _ •. yoke_, _____ __ •

fAl200D/ M7 __ .I Shaft_. ___ __ ._

4AI200A/246 __ .1 Speed ",mlrol di .. 1 ......,"'_ blr •

T .. ke-Ilp .... 1 shaft. S" OD. +\ , ' hole ; O.I~" ,·hick,o,,,,,I , f4- oW llet­""",w hole. "peeisl.

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Speed co .. trol ....... mbly • •.•• _. _.. . .

Speed Indlc.tor di .. l.hal1., ~." diam_ eter. , t ... I, 1.28" long, Inelude. b .... di .. l ","T, 32-pitch; 14 , ... th. ~." f."." Boot<>n Geo.r Works fO-1 &.~, opeei .. 1.

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2~822_7 _____ • .I K noo _______ _ _ Bl.ck, molded brohli"'. for W' ahaft ; W'di&meter knu.I...:I .im, ,&-292-16.

UI200All02 ____ ! a_ket _______ 1 Amplille-r, "haMil, "peei . !. . __ __ _ . . __

, 4AI200A/ I02 ___ • B.r.cket ___ ____ I Amplifier chaNlo, opeelaL • • .•• _ •• • _

I ZZI57l1.7 _____ J Cabl!let • ____ I 1011" x 21" ~ Ill", 'DL-I28 ___ ___ _ _

I 2Z1~73.7 __ ____ .1 Cabinet . •.• __ '! lOW' • 21" I 137>" st .... l .. b i....t,

• • 4A I 200D/600 ___ 1 C .. bl"et_m_ bly.

8A3240 ReeL ___ ___ __ _

'D1.- 128. C .. blnet .. I~h h ... d,,· ... e ..-mbled.

epedal. 16-mm, 400' c"p&eit~· film reel • • beet.

. t ;"'l. bl ... k "",,,ne l fini.h, .und_ B.d .

3A3511O- L. ____ ) Po,.er <><>rd __ __ 1_ . __ ._ _ _ _ _ _ _ ____ _____ • __ __ __ _ _

ABC I 124 __ ____ __ 1 3EMQIL _______ 1 Cord _________ _

DJo' OHJ

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2T1I6 ____ • _____ .I Tube VT-II6 __ •

2T1l6 ••••• _ •• _.1 Tube VT-115 _.

2...onduet-or . rubbe. _vere<!. 2_pole mAle plug one end , 2_pole femAle plull other end. 3' long •• r-iAI.

01_ B t",i n triode metal, I· ... "um. ,6N7.

Be. '" PO"'" AmpHfier w et.&!, v ... uum.

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Aropllft e r b ... "ket, ri~ht.h."d.

Ampli fte r b.o.eket, I~t_h&n<l ,

Keyer ~ .. binet _____ _

Keyer "abinf't __ -- --I P- M __ • • • __ •

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Ke~''''' e.t.inet ___ __ J . ___ ______ __ _ T .. pe __ ____________ : B"'H .. __ ___ _

A ... PO"'" linl ___ __ 1 ____ __ __ ___ _ _

A ... po ... ·e. line __ __ . 1 __ • __ ._ •• ___ •

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Pueh_pull output __ _ 1. _ •• •••• •••• _1

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• ~ n. TABLE OF KEPlACEABLE PARTS-Continued.

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I 2'l'U2 ••••• • • •• • TuIN VT- 2&2._

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6L~:L._n_t_ 1 SCO ... . . ... .. .

FuJl . ... ve . biJp:b, v..,,," ... f'tIOUAer, ,lui, UUfG.

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12, .w." drive , platfld, '2.

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aecUtler tube. __ , _ . ,. _. _. _. _ • __ t_

Phot.oI.ubot • • • •• • ••• RCA ••• • • •••

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panel ; dial tO lup-

"". PuLLer ret.JDe' ••••• j . ... . ....... .

61.310&-12,.0, •• : Nut ________ __ 1 ,/1--82 1r.nurltld, br .... , blae1r., DickeL- I Photo oGver .,,""'P t. ____ _____ , __ _

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&R6M9II .. _ • _ •• 1 Wreneh . • _ . __ J Allen .tet«rew, f4 . __ . _______ ___ ..• 1 ~mo\'e a nd repl_ .......... __ . _leo ........

IIRM488 ••. _ ••• 1 Wrueb •• _ ... -I A1w,n """''''''', U , '". _ • ______ • __ •• &mo .... nd ... ~ .... -........ ' .toe ....... .

4A 1201)1>/621 •• _I " ""ke • . __ • •••• I. _ .. ___ _ .... _ ........ ___ ... ___ .. __ 1 Tape-puller ollNl . __ • ____________ _

4AL200D/1I:U. _.1 "-mbly .. .... 1 Cooe-driffn roller _mbly ... _ .... . 1 V .. t a ble I p.., d , • • • • • •• _ ••••• drI« •. 4." 120001$30 •• 1 Aa.mbly ____ __ I Tape-puller .haI. _mbl,. _______ -.1 Tape puller __ • _ •• •• 1 •••• _ •• _ ••••• ,

4AI200D/ Mli . _.1 ('oUt •• _ •• ____ .1 Indiutor dial I G- IM ._. _. _____ ..•• 1 •.•...... ________ . .1 BOW ______ _

4AI2000/ 697 __ .1 A_mllly ___ • _.1 I ndlca.or diaJ., _ mhlf, .....•...•.• ___ _ • ______ • ___ • ___ ._. ___________ '

fA 12OO0 /M2. __ I ~.rin,. bro""' 1 8ron ... bMrin' __ __________________ • ___________________ • ____________ _

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%I. NAMES AND A..DDaESSES OF MANUFACTUBEItS.

A AIR AM ASC BGW B.H BUD D EBY GE G1 G-P BBJ IRC K -K LF M MA M-Y P-K P-M RCA SP TH

Aerovox Corp., New Bedford, M .... Atlantic India Rubber Worke, Inc., Chie&gO, Ill. American Phenolic Corp., Chicago, 1U. American Sc!'ew Co., Providence, R . I . Boston Gear Works, fuc., New York, N. Y. Bell d: Howell Co., Chicago, 1U. Bud Radio, Inc., Cleveland, Ohio. Drake Electric Works, Inc., New York, N. Y. Hugh H. Eby, Inc., Pb.i1adelphia, Pa. General Electric Co., Cleveland, Ohio. Oeneraiinduatrica Corp., Elyria, Ohio. Groove Pin Corp., Union City, N. J . Howard B. JODeII, Ine., Chiugo, III. International RllIIistance Co., Philadelphia, Pa.. Kurz-Kaaeh, Inc., Dayton, Ohio. Littlefuse, Inc., Chicago, Ill. "'rank W. Morse Co., New York, N. Y. P. R. Mallory, Inc., Indianapoli6, Ind. Mallory- Yaxley Co., Indianapolis, Ind. P&rker_K&lon Corp., New York, N. Y. Par-Meta] Producta Corp., Long bland City, N. Y. RCA Mfg. Company, HRITilIon, N. J . Sprague Specialties, North Adama, Ma88. Thordanon Electric Manufacturing Co., Chicago, Ill.

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0.'9' ~11n>m UNIV[RlfTY Of CALIfORNIA

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