Motorola VWM6O User manual

AUTO RADIO
MO DEL
VWM6O
GENE RAL I NFO RMAT I ON
TYPE - Automotive type 6 volt superheterodyne receiver
designed for qustom installation in 1960 Volkswagon
cars. This receiver contains a transistqr output
stage, a transistor power oscillator (for B+ suppt-y)'
and four miniature tubes.
TUNiNG RANGE - 540 to 1610 Kc IF - 262.5 Kc
OPERATES FROM - 6 volt storagebattery (negative ground)
TUBE AND TRANSISTOR COMPLEMENT
bt'llo Lonv
blJAb l.t, amp
6CR6 DeI-AVC-AF amp
5BF6 Driver
MN-73
or 2N176 Transistor Pwr amP
MN-73
or 2N1?6 Transistor pwr osc (for B+ supply)
DIAL SCATI BACKGROU R CALIBRATION MARK
I
MOTOROLA AUTO RAD IO WARRANTY SERVICE
I. The definition of a Motorola Branded Model is one that
is branded with the Motorola name, and distributed to deal-
ers through authorized Motorola Distributors"
Z. Before perlorming a warranty repair on a Motorola
Branded Auto Radio, you must first receive from the cus-
tomer the Customerrs Warranty Policy. This policy must
be filled in by the selling dealer at tJ.e time of retail pur-
chase. The Customerrs Warranty Policy must show tJre
radio to be within th. oio"tv-dav *.""arfv p f the re-
pair is to be handled offidio war-
ranty Plan.
3. The removal or reinstallation of the radio, the elimina-
tion of motor.noise, tire static, electrical interference' or
faulty installation and aerial repairs are not considered as
warranty repairs. Consequently, charges for these serv-
SERVICE
1. RADIO POLARITY - WHEN SERVICING THIS RECEiV-
ER, THE "A" LEAD MUST BE CONNECTED TO THE POS-
ITIVE SIDE OF THE POWER SOURCE. IF CONNECTED
OTHERWISE, RECEIVERWILL NOT OPERATE AND DAM-
AGE TO COMPONENTS MAY RESULT.
Z. POWER qUEPLf AEOUIREMENTS - lt is preferable to
chargei) in place of
a battery eliminator. If a battery eliminator is used, it
must be well regulated and filtered.
3. POWER TR.ANSISTOR REPLACEMENT -When replacing
TUOTOF'OLA
STATION PROCEDURE FOR BRANDED MODELS
ices are to be borne by the customer.
4. Fill in tle Motorola Auto Radio Warranty Labor Claim,
Part No. 54P480884, and mail white and green copies to the
MotorolaDistributor serving your area. The yeliow copy is
to be retained by the Warranf,y Service Station for his files"
5. Delective parts for warranty repairs made on Motorola
Branded Auto Radios are to be sent to your Motorola Dis-
tributor for free replacement, supported with the defective
parts return form which you are now using.
6, Only tlose service shops authorized by their Motorola
Distributor can perform repairs within the warranty period
on a no-chargebasis tgthe customer. If you are not already
authorized as a Motorola Auto Radio Warranty Service Sta-
tion, and you are interested in handling this service, please
contact your Motorola Distributor for complete details.
POINIER . WIIH TUIUR STT TO
1610 KC, SET POINTER TO MARK SET TUNER SO CORES ARE
AND CEMENTTO DIAL STRING. OUTOF COILS (1610 KC)
DIAL STRINGING DETAIL
IURNS
I TURN
TUN I NG
SHAFT
CHICAGO 51, tLLlNols
NOTE S
a power transistor, be sure transistor insulator is in place
and well greased andthat the mounting screws are securely
and evenly tightened. Use only the transistor specified in
the ReplacementParts Listfor replacement. SeeNotes 4 & 5.
4. POWER TRANSISTOR INSULATOR - When replacing a
@er transistor insulator, be sure to
ioatbothsidea of insulato! withDC-4 grease (Motorola Part
No" 11M49048?) to insure ProPer heat dissipation.
5. POWER TRANSISTOR CURRENT ADJUSTMENT - After
a powsr transistor has been replacedr the collectorcurrent
Tll,(C.4545 WEST AUGUSTA BLVD.
Price 1O Ceuts Prihted in U.S.A.
Part No. 68P543946 11-59

shouLd be checked and adjusted for proper operation.
a" Insert.a low range (0-1 or 0-Z amp) DC ammeter ire
the primaryground returnlead of the output trangformer
(T4). Connect tl.e negatiwe post of the meter to ground.
(s ee Schematic).
b. Turn the radio on and allow it to heat up for about 15
minuteg.
c. Adjust Rl3 for a reading of 560 ma with 6.3volts input
to the radio [A" lead.
NOTE: Two values of radio input voltage are given as a
convenience to service personnel in order to accomodate
different powet sources. The current value stated on the
Schematic Diagram is for 7 volts input to the radio trAt'
Iead.
ALIGNMENT
Connect an output meter across the speaker voice coil. Set volume control to maximum. Attenuate signal generator output
to maintain 1.79 volts on output meter at all times to prevent overloading receiver.
NOTE: Do not perform steps 3* 4, 5 & 6 unless the tuner has been tampered with or components have been replaced. Be-
fore proceeding with step 3, back tuning cores as far as possible out of coils to minimize their effect on trimmer
adjustments.
Ant recept thru
dummy (s ee fig)
lt
Repeatsteps4&5
Iuntil no further increase, then cement tuning cores in place; step 5 should be last adjustment.
ANTENNA TRIMMER
3"
4.
5,
6.
1610 Kc
lZ00 Kc
1610 Kc
Hi end stop
Ttner carriage
9 /3Zt' tuom hi
end stop
Hi end stop
Weak station
around 1400 Kc
5,6 & 7
8,9 & 10
5,6 & 7
1
Adjust for maximum.
Adjust for maximum.
Adjust for maximum.
With radio installed in car and
antenna lully extended, adjust
antenna trimmer for maximum.
PLUG TO FIT RECEIVER
\-lrrerurua REcEPTAoLE
i-ooume---l\ TO REOEIVER
+ANTENNA
RECEPTACLE
iohr. l\ REoEPTAT
- i tueral sHTELD caN
| 'f i iiiistaE'iriicieo
orr ro esenozrr-o TO PLUG
STEP GENERATOR
CONNECTION
GENERATOR
FREOUENCY
(400 cycle mod) TUNER SET TO ADJUST REMARKS
IF
l.
RF
2"
ALIC
I
ALlI
NMENT
Ant recept thru
,1mf & chassis
;NMENT
Ant recept thru
dummy (s ee lig)
262.5 Kc
1610 Kc
Hi end stop
Hi end stop
1,2,3 &.4
5,6 &.7
Adjust for maximum.
Adjust for maximum.
(
I
ANT TRIM TR IM IST IF
262.5 KC
TRIM
osc coRE ANT
FRONT VIEW WITH ESCUTCHEON REMOIED CORE
ALIGIiTIENT I.oCATIO}IS
DIJXIY A}ITEI{I{A

MNR OR 2NI76
TRANS ISTOR
DET.AVC
DRIVIR CI6 -AF AMP T2
PARTS I,OCATION
68E6
CONV 6CR6 MN73 0R 2Nt7o
I
'fTll
u lr rlr
T2 CONN
*\)!;'o'u"o*
TRANSISTOR CONN
[1N73 0R 2N]/6
PWR 0SC
NOtrS:
CAPACIToRS - Decifral value5 in MF, all otturs in Mlff
unless otheruise specif ied.
VoLIAGI5 - \€.!Lred lrom poinr'_dicdted lo chass;s
with a WVM. Nb signal input. Tolerance +tM.
INPUI VOL]AGI .7V DC.
TUNINC RANGT - 540 KC lo 1610 (C.
lF FRIQUtNCY - 262.5 KC.
+ - lndicat€s cltrhise rolalion of control.
CAUTION
.A'' IfAD MUST BI CONNECIFD TO POSITIVI I+) SIDi OF
POI4ER SUPPLY, RADIO W ILL NOT OPTRATT AND DAI!1AGE
TO COMPOISNTS WIIL RiSULT IT CONNTCTED OTHERWISE.
EIAS CONTROL
RBI
r2i I
SCEEUATIC DIAGRAU

REPLACEMENT PARTS LIST
NOTE, When ordering parts, specify model number of set in addition to part number and description of part'
Electronic parts of equivalent rating are not necessarily of equivalent standards. The conponents listed
in this Service Manual have been chosen for reliability;nd applicability to the specific circuits lnvolved.
For maxinum custoner satisfaction and minimized call-backs, use the exact Motorola parts replacenent. l
Ref. Part
No. Nunber Descr ipt ion Ref, Part
No. Nunber
44A124332
MEC}iANICAL PABTS
43K543245
428733793
'15K543815
r3D543242
I 4A5438 10
25?O5 t
78543267
IKs43277
9K54199 1
5K 13896
348543390
3K560695
3S 129994
Iv543435
9A472148
9K543387
9K539 132
98542 339
257087
c-2 agt2229r
c-3 2DK54rOr4
c-5 8R121005
c-6 20A485708
c-7 2lR115593
c-8 2tR4A2726
c-9 2lRr227a9
c- 10 2 ]R 125 165
c-11 21A542344
c-rz 2\R1a2',726
c-13 21R410118
c-14 64K530177
c-15 23B543394
c-16 238s43393
c-17 21A542384
c-18 64K5301',77
c..19 aK122016
c-20 2rK740A06
C-21 21A542344
E-1 24K539955
E-2 50C543225
E-3 48K543405
B-4 65R10867
E-5 65R16248
L-1, 2, & 3
L-4 258543396
Resistors - Note:
R-1 6KI22324
R-2 6K12 1687
R-3 6Kf28952
R-4 6K1223 13
R-5 18K544000
R-6 6K119407
R-7 6K119407
R-8 6Kr22324
R-9 6R6015
R-10 6K119408
R-11 6Kr22324
R-12 6Kt22324
R-13 78K542493
R-14 6K543800
R-15 6A488139
R-16 6K127960
R-17 ],7K4aa266
R-18 6R5614
R-19 6K119926
R-20 6A543419
ELECTRICAL PARTS
C-l 2085,14017 Capacitor, nica trimj 40 mf to 430 nmf
(inc1 brkt)
Capacitor, paPer tub: .002 mf 1OO0V
Capacitor, nica trin: 20 nnf to 120 mnf
Capacitor, Paper tub: .O5 mf 2OOY
Capacitor, nica trim: 395 mnf to 47o nml
Capacitor, cer disc: 47 nnf sOOV
capacltor, cer disc: .01 mf 500v
Capacitor, cer disc; .01 mf 500V
Capacitor, cet disc: .0o2 nf 500v
Capacltor, cer disc: .05 nf sOV
Capacitcr, cer disc: .01 nf sOOV
Capacitor, cer disc: 330 nnf 50OV
Si,arkPlate: tx 1-318
C;pacitor, electrolytic; 5a/lsOY
Capacitor electrolytic: 50,/150v-looo/8v
Capacitor, cer discS .05 nf 5OV
SparkPlate" 1xl-3,/8
Ctpacitor, paper tub: .5 mf 10ov
Capacitor, cer dlsc: .025 MF 200V
Capacitor, cer discr .05 MF sOV
Choke, ant spark
Speaker, PII: 5"; 3.20 vC
Rectifier, selenium
Bulb, dia I light : 6\ i #44
Fuse, 9 anp
See Tuner Parts List
Choke, filter
A11 resistors are insulated carbon type,
unless otherwise sPecif ied.
1 neg 20% l/2w
17 ,OOO 20% \/2W
180 ro% r/2N
100,000 20% 1/2\l
Ccntrol, dual & switchx RsA Vo1 2M;
R5B Tone 2M
3.3 neg 20% l/zN
3.3 neg 20% I/2tN
1 meg 20% I/2w
220,OOO 201a r/2\t
10 meg 20% I/2u
). nee 2o% l/2w
7 meg 2o7o I/2u
Bias Control: I25
Thernistor 3 10@ 25oC
5. 6 ro% lW
1000 20% t/2N
Wirevound ! .47 10% l/2\\
56 10% r/zw
2700 10% 7/2W
Varlstor, special
T-1 248543246 Transformer,
T-2 24K543287 Transformer.
T-3 258543386 Translornei,
T-4 25C543416 Transformer,
T-5 25C543395 Transforner,
648543874 Bracket, radj-o ntg (front)
7A543889 Bracket, radio ntg (rear)
88538244 Condenser, generato!
8A4491 Condenser, noisesuppression
32B543887 Gasket
36K542OO5 Knob, dunny
368522020 KDob, tone
36K542973 Ktrob, tuning & vo1
2513?6 Nut, hex: 3,/8-32 (radio ntg)
3Sl-28062 Screw, tappingi #10 x 3,/8 (spkr ntg)
6A414l Suppressor, noise
1v544037 Trinplate, chrome (inc1 rubber tubing)
4K481689 washer, felt (knobs)
TUNER 77K563O73 11UT-300) pARTS
L-1 24K562246 Coi1, antenna
L-2 24K562245 CoiI, RF
L-3 24K562244 Coi1, osc
77K563073 Tuner, MT-3O0; conplete
76K536535 Core, i!on
76K56o447 Core, iron
5A533933 Gronmet, core ntg
28533929 Nut, tension drive
22K534525 Pin, roll (tuning shaft)
47K563O75 Shaft, nanual tuning
26A535533 Sleeve. iron (ant & RF coil)
264535534 Sleeve, iron (osc coil)
418536529 Spring, retaining (tuning shaft)
Descr iP t ion
Transistor, Type MN73: PNP iunctj.on
(pwr anp & pwr osc)
Bushing, ntg (nanual tuning shaft)
Clip, IF ntg
Cove!, botton
Escutcheon, chrone
Insulator, transistol'
Nut, hex: 3/8-32 (voL & bushing mtg)
Plate, dial scale ret
Poirter
Receptacle, fuse
Rivet, shoulder
Sca 1e, dia 1
Screw, tapping: 6-20 x l/2 (trans ntg)
Screw, tappingt 6-20 x t (rect ntg)
slider, pointer: incl rivets
Socket, antenna
Socket, pilot light
Socket, tube: 7 Pin nin
Socket, 2 pln (transistot)
Speednut, dial scale ret
ACCESSORIES
E}4ENT PARTS
PARTS &
lst IF:
2nd IF:
dr iver
out put
pwr osc
262,5 Kc
262.5 Kc LIM I
44CI24246 Transistor, Type 2N176; PNP junction
(pwr anp & pwr osc)
Note: The volune of replacenent on the following parts is sna11,
consequently, it is suggested t,lat ordering be done only
as required.
l\544O42 Cover, rear: incl trans socket
1V544O36 Kit, radio ntg Parts
c2t 6BF6
DR IVE C8 RIO RII 6CR6 RIz R9 R7 R6 CII RI El DET-AVC-AF AIVIP
l1
\
68A6 MN73 OR
IF AMP TRANSISTOR 2N176
PWR AMP
PANTS LOCATION
CONV R2