Motorola 52R12 Schematic

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Product Information:
Model:52R12
Manufacturer:Motorola (Galvin)
Description:HS-289

Schematics Content:

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Page 1:

MOTOROLA A -3
GENERAL INFORMATION
TYPE - Ac-Dc table model superheterudyne receiver with
"printed" circuit and Ferrite Magnetic iron core
MODELS 521111, 52R12,l
RECEIVER MODELS ~ MOdei COIOY
SZRII Walnut
521112 Ivory
52RI3 Maroon
521114 Gray
SZRI6 Red
TUBE COMPLEMENT - Type Function
IZBEG Converter "
lznne ir Amplifier
12-*T6 De* AVC 8- AF Amp TUNING RANGE - 535 to 1620 Kc IF _ 455 Kc
SOC5 Power Amplifier
35W4 Rectifier POWER SUPPLY - IIT volts AC O! DC; 35 watts
INSTALLATION I: OPERATING INSTRUCTIONS
POWER SWITCH ar VOLUME CONTROL. Operated with the
smail lower knob. NOTE: Reverse the line cord plug in
the wall outlet if radio does net operate from Dc. When
operating from Ac, reversing the line cord plug in the wall
outlet may sometimes improve reception.
TUNING. Stations are tuned in with the large upper knob.
TO REMOVE CHASSIS FROM CABINET:
I. Remove the four screws which hold the back cover, and
remove the cover and line cord.
2. Pull off the two control knobs irom the front of the re-
3. Remove the Phillips head ,screw under the tuning knob,
on the front ofthe receiver.
4. From the back, remove the screw which holds the line
cord plug.
1 5. Disconnect the leads from the speaker.
e. From the hack, remove the three screws which mount
the chassis. cAUT1oN; Do not lose the insulating washers
on the screws -they prevent damage to the printed circuit
ANTENNA. A bui1t>in Ferrite Magnetic Iron Core Antenna
eliminates the need for an outside antenna. When receiving
'a weak station, roteie the receiver slightly lor best signal
CAUTION: Never eonnect the radio chassis to awater
pipe, radiator, or other ground.
NOTES
by the heads of the screws. See Figure 1.
7. Slide the chassis from the cabinet.
CIRCUIT DESCRIPTION
i. The circuit of this chassis is conventional - there are
no`bui].t.-in resistors or capacitors. Leads are printed on
both sides ofthe chassis hase, thereby replacing the usual
connecting wires and making wiring more unilorm.
2. The metal printing extends through all the hdles on the
chassis, connecting circuits on the front with those on the
3. Reference to the schematic diagram and to Figures 3
and 4 win permit the circuit to be traced easily, Figures
3 and 4 shew the front and rear ofthe chassis, wired and
(C)John F. Rider

Page 2:

PAGE 23-3 e i OTOROLA
MODELS 52R11, 52R12,
SAFETY PR ECAUTIONS
l. The chassis of this receiver is connected directly to the
power line. However, the power cord circuit is broken by
an interlock when the cabinet back is removed for replacing
tubes. When aligning or servicing the chassisffrom AC, an
isolation transformer should be inserted between the power
line and the chassis.
Z. D0 not service the chassis on a metal plate, because of
the possibility of a short circuit.
1. Use caution when handling the chassis with power ap-
plied, because all high voltage leads are exposed.
4. The outer edges of the chassis and the large printed
areas in the center are at ground potential.
COMPONENT REPLACEMENT
lu To prevent tube breakage, remove them before replac-
ing components. CAUTION: Remove the tubes only by pull-
ing them straight out, Wiggling a tube may bend a socket
clip causing poor contact with the tube pin,
Z' WHEN REMOVING DEFECTIVE COMPONENTS USE
ONLY A SMALL SOLDERING IRON (60 WATTS OR LESS)
TO AVOID DAMAGE TO Tl-IE WIRING. DO NOT USE A
SOLDERING GUN. WARNING: THE LEADS ARE VERY
THIN, AND EXCESSIVE HEAT WILL BURN THEM OR
LOOSEN THEM FROM THE BASE MATERIAL.
3. Printed connections or leads, if damaged, may be re-
placed with a jumper of regular hookup wire,
4. It is recommended that IF transformers, the volume
control, or the electrolytic capacitor he removed by im-
mersing all the lugs simultaneously into a small soldering
pot. The component may then be lifted off the chassis
easily. lf a soldering pot is not available, heat each lug
individually with a small soldering iron, and shake on as
much molten solder as possible. Then, by alternately heat>>
ing and loosening each lug, the entire component will be
freed. The disadvantage of using a soldering iron instead
of a soldering pot is that the printed connections may be
pulled loose from the chassis.
5. An individual tube clip may be removed by squeezing it
with a pliers and then unsoldering it. The new clip snaps
into the hole.
6. Resistors or capacitors may be removed by unsoldering
one end at a time.
CAUTION: Clean all the solder from the holes before in-
stalling a new component. no not let the solder run onto an
adjacent lead, as a short circuit will be created,
1. Be careful, when removing or replacing the volume con-
trol mounting nut or gang mounting screws, that the print-
ing around the holes is not damaged.
8. When the chassis is fastened into place in the cabinet,
he sure the insulating washers are on the mounting screws,
otherwise the heads of the screws may damage the printing.
ANTENNA
1, A Ferrite Magnetic Iron C0re Antenna replaces the con-
ventional "pancake" loop in this receiver. This newer loop
is more compact and efficient than the previous type. Its
inductance has been pre-set at the factory and requires no
adjustment in the field.
Z. Under Certain circumstances, in early models, AC hum
was induced into the _loop antenna. This condition was cor-
rected in later models by repositioning the loop. Figure 3
shows the revised location.
3. The service man may convert early models, if neces-
sary, by replacing the loop mounting insulator with the later
type, shown in Replacement Parts List. The loop coil it-
self remains the same.
NOTE; If AC power is used, insert anisolation transformer
between the power line and the receiver to avoid hum and
electrical shocks. lf an isolation transformer is not avail-
able, connect the low side of the signal generator to ground
(the outer edges of the chassis) through a .l mf capacitor.
1. Connect a low range output meter across the speaker
voice coil. '
2. Connect the low side of the signal generator to ground.
3. set the signal generator for 400 cycle, 30?/1, modulation.
4. Turn the receiver Volume Control to maximum.
5. Use a small fibre screwdriver for aligning the IF and
diode transformers (a -'R-Tran" alignment tool is recom-
fi. As stages are brought into alignment, reduce the signal
generator output to a level which produces less than .40
volts (.o5 watt) across the voice coil to avoid overloading
the receiver.
1. see Figure z for adjustment locations and the following
chart for procedure.
ALIGNMT-:NT CHART
DUMMY GENERATOR GENERATOR GANG
f STEP ANTENNA CONNECTLON FREQUENCY SETTING ADJUST REMARKS
IF ALIGNMENT _ _
1. .l mf Grid ol conv. 455 Kc Fully 1, 2, 3 ti 4 Adjust [or maximum.
(pin 1, lZBE6)> open (IF cores)
RF ALIGNMENT
z. .1 mf Grid of conv. lezo Kc Fully 5 (osc) Adjust for maximum.
(pin 1, IZBEB) Open
3. Radiation loop* 1400 Kc Tune for 6 (Ant) Adjust for maximum.
_ max .
*Connect generator output across 5" diameter, 5 turn loop and couple inductively to receiver loop. Keep loops at least
(C)John F. Rider

Page 3:

___ __ MOTORQLA PAGE 23 37
MODELS 52R11 52R12
A CHASSIS MOUNTING SCREW
Pwa AMP \J DET-AVC-AF
FIGURE 1. REAR VIEW OF RECEIVER (LATE MODEL)
AMP
Y FIGURE 2. TUBE AND TRIHHER LOCATIONS (LATE MODEL)

Page 4:

PAGE 23- MOTOROLA
MODELS 52R11, &R12,
FIGURE 3. FRONT VIEW OF CHASSIS - WIRED AND BLANK (LATE MODEL)
IF AMP
6 'John F. Rider

Page 5:

MOTOROLA PAGE 23 39
35w4 f=2==:?Hi?> guy '_, -A
socs iam R R 5; \ _ ;
IF AMP
FIGURE 4. REAR VIEW OF CHASSIS - WIRED AND BLANK (LATE MODEL)
O John F. Rider

Page 6:

PAGE za-4o Moronoux
PWR AMP
9 John F. Rider

Page 7:

MOTOR LA PAGE 23 41
MODELS 521211, 52R121
Q John F. Rider

Page 8:

PAGE 23-42 Mor Roux
MODELS 52R11, 52R12,
PARTS LIST
NOTE: When ordering parts, specify model and chassis numbers of set in addition to part number and description oi p81'7~~
Ref . Part List Part List
NO. Number Description Price Number Description Price
CHASSIS PARTS - ELECTRICAL 2S7051 Nut, hex: Palnut; 3/8-32 x 9/16
(volume control mtg) .......... doz .15
Capacitors 2811610679 Plug, line cord (interlock) ....... .15
C-1 1913610626 Variable: 2-gang ..... . 2.75 463480108 Stud, trimount (ant insulator
C-2 8119821 Paper; .05 mf 200V ......... .20 mtg) ........ .. ................ doz .15
C-3 2111115905 Ceramic: 220 mmf 500V ....... .25 2911620057 Terminal, pin (on spkr 1eads)..doz .20
C-4 SR490232 Molded paper: 47,000 mmf 400V .30
C-5 21114827260 Ceramic disc: 10,000 mmf 450V .30
C-7 2111482726 Ceramic disc: 10,000 mmf 450V .30
.CABINET PARTS
L-1 2411610646 Antenna Loop; with core .... .50-* 160611255 Cabinet, table mvdelz walnut
L-2 2418520875 Oscillator coil .......... .90 (521111) ..... ................ . . 3.60*
16K611256 Cabinet, table model: ivory
Speaker (521112) .................. . . . . . 4 .SOX
LS-1 50K620141 l6K61l258 Cabinet, table model: maroon
or 50K620142 Speaker: 4" PM; 3.2 ohm VC; (521113) ..... . ............... .. 4.80*
indudes 1_3 and ?_9 ____ 4,951 l6l(6l1259 Cabinet, table model; gray
16K61l260 Cabinet, table model: green
Resistors (521115) .... ..... . ........ ........ 4.S0*
16K61l2Gl Cabinet, table model: red (52Rl6). 4.S0*
Note: All resistors are insulated carbon type 3011610538 C?\'d>> 111191 with Plug 3? I`eCEURPt3C19 ~95
unless 9151191-wi5e Specified, 1X6l0655 Cover, cabinet back: with line cord 1.40
15K620103 Cover, speaker: walnut (521211) .... .70
R-1 6116028 22,000 2041, 1/2w___ _,,, do; 1,20 15K620104 Cover, speaker: ivory (521112) ..... .70
11-2 6R6018 100 201, 1/zw __,__,_____ dog 1,20 15K620105 Cover, speaker; maroon (521113) .... .70
R-3 6112118 3.3 meg 20% 1/ZW ....... doz 1.20 1511620106 C?V9?'| 5Pe3k91`i ?l`3Y (5ZR14)--U .70
R-4 1811610857 Volume control: 1 meg; with 1514620107 Cvver, SP93k9l'2 Sree!! (521115) ..... .70
swingh ____ _ ________ _ _ _ _ _ _ _ _ 1,00 1511620108 Cover, speaker: red (521115) ..... . . .70
R-5 6112109 10 meg 20% 1/2W ........ doz 1.20 36K6ll308 Knob, tuning: black (52R11, 52Rl3,
R-7 6116032 470,000 20% 1/2W ..... ..doz 1.20 3611620090 Knob, tuning: ivory (521112) ..... .. .40
R-8 6115683 27 10% 1/2W ....... .... d OZ 1.20 3611620156 Knob, volume control: black (52R11,
R-9 6113992 150 20% l/2W... .... doz 1.20 521213, 52Rl4, 521215, 521116) ..... . .10
R-10 6113953 1000 201, 1w ,,,, _,___ _20 36K610642 Knob, volume control: ivory (521112) .10
Transformers Phillips flat head; cad pl (chas-
T-l,2 24K610639 IF and Diode Transformer: sis mtg - through front of cabi-
455 Kc; comp1ete........ . 1.35 net).... .......... ....... ..... doz .20
1'-3 25K6l0631 Dutput Transformer-...... . 1.05 35115237 S?l'ew, thread wiring: 6-20 X 5/16
pl hex head; cad pl (spkr mtg)doz .40
Part List 3S48B009 Screw, thread cutting: 6-20 x 3/8
Number Description Price pl hex head; cad pl (power plug
mtg) .......................... doz .15
CHASSIS PARTS - MECHANICAL 3S115240 Screw, thread cutting: E-20 x l/2
, pl hex head; cad pl (chassis mtg
}42A610632 Clip, tube pin .......... . . . . .Per/C .50 8: back cover mtg) ........... . .... .05
1X620210 Insulator, antenna loop: fibre; 25400014 Speednut (spkr cover mtg) ......... .05
with lug (replaces 51A6l0757 in- 4K611121 Washer, flat: paper (chassis mtg
sulator shown in Fig. 5). .... .20 screws) .... ...... .......per/c .50
PRICES SUBJECT TO CHANGE WITHOUT NOTICE
*Plus Federal Excise Tax A; currenz Rate

Page 9:

Ill
set in addition to part number and description of part.
rts, specify 'model and chass
When ordering
NOT
revisions oi or additions to the original items listed in the HS-Z89 Service 174% A.
The following parts are
n Price
Number
484337 Ceramic: dual 250
0
places C-3 ,
MODELS 52R11, 52R12,
can
._| _n SEQ >>- 5 "J: a: 8
6 John F. Rider

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