Motorola 55C1 User manual

Motorola
SERVICE MANUAL
MODELS
SSC1 MAHOGANY
S5C2 WHITE
SSC3 MINT GREEN
SSC4 CLOVER PINK
CHASSIS
HS-456
GENERAL INFORMATION
TYPE - AC table model superheterodyne receiver with plated
circuit chassis and loop antenna,, This receiver
has a self-contained electric clock for automatically
controlling the operation of the radio and the ap¬
pliance outlet.
TUNING RANGE - 535 to 16Z0 Kc IF - 455 Kc
TUBE COMPLEMENT - 1ZBE6 conv; 1ZBA6 IF amp; 1ZAT6
Det, AVC, 1st AF amp; 50C5 pwr
amp; 35W4 rect.
POWER SUPPLY - Operates from 117 volt, 60 cycle, al¬
ternating cur rent only. Power consump¬
tion 35 watts.
APPLIANCE OUTLET - For use with 117 volt AC appliances
rated only at 1100 watts or less.
CLOCK - Duplex self-starting electric clock. See Service
Notes for clock repair information.
INSTALLATION & OPERATING INSTRUCTIONS
Your Motorola is ready to operate when you plug it into
any 117 volt, 60 cycle AC power line. Do not attempt to op¬
erate on DC as the clock motor will be damaged.
The clock is self-starting and will operate when power
is plugged into the power outlet. The sweep second hand
will indicate when the clock is running. To set the hands
on the clock to indicate the correct time, pull out AUTO¬
TIME SET knob (on rear of radio) and turn in a clockwise
direction only. The self-starting feature, in the event of a
temporary electric power interruption, will re-start the
clock but it will be necessary to correct for time lost by
means of the AUTO-TIME SET knob.
Radio reception can sometimes be improved by revers¬
ing the power plug in power outlet. Try it both ways and
leave it in position giving best reception.
A built-in loop antenna eliminates the need for an out¬
side antenna. The antenna is somewhat directional, there¬
fore, when receiving weak stations, reception may some¬
times be improved by rotating the receiver slightly in either
direction.
MANUAL RADIO OPERATION
1. Turn OPERATION SELECTOR knob to ON. Allow a
short period of time for tube warm-up.
Z. Tune to desired station with the STATION TUNING knob.
3. Adjust volume control to desired level.
4. The radio will play until OPERATION SELECTOR is
turned to OFF.
AUTOMATIC CLOCK-RADIO OPERATION
1. Turn OPERATION SELECTOR knob to ON. Allow a
short period of time for tube warm-up.
Z, Set the radio dial to the station you would like to hear
at any pre-determined time, up to twelve hours in advance.
Adjust volume to desired loudness.
3. Push in AUTO-TIME SET knob (on rear of radio) and
turn in a clockwise direction until RADIO ALARM SET
POINTER indicates the radio is to be turned on automati¬
cally.
4. Turn OPERATION SELECTOR to OFF and then to AUTO
position. Leave it in AUTO position.
5. The radio is now set to turn on automatically at time in¬
dicated by RADIO ALARM SET POINTER. It will continue
to play until OPERATION SELECTOR is turned to OFF.
BEDTIME CONTROL
The bedtime control feature is a timing device for turn¬
ing the radio and appliance off after any pre-set interval of
time up to one hour. This feature allows you to listen to
the radio while you are in bed, with the assurance that it
will shut off automatically after you are asleep. Or F you
may turn off a lamp or appliance, if desired.
If appliance is not desired during the time the bedtime
control is in operation, disconnect appliance from recep¬
tacle.
TO SET BEDTIME CONTROL
Turn BEDTIME CONTROL knob clockwise. The farther
the control is turned, the longer the radio will play, up to a
maximum of 60 minutes.
MOTOROLA, INC. 4 54 5 AUGUSTA BLVD. CHICAGO 51, ILLINOIS
Part No. 68P633301
Price 5 Cents
Printed in U.S.A.

BEDTIME CONTROL AND AUTOMATIC OPERATIONS
COMBINED
By combining the bedtime control and automatic radio
operation, it is possible to turn the radio off automatically
and to turn it on again automatically. Thus, you may go to
sleep at night with music and be awakened with music again
the following morning.
TO USE THIS FEATURE, SET CONTROLS AS FOLLOWS:
1. Push in AUTO-TIME SET knob (on rear of radio) and
turn in a clockwise direction until RADIO ALARM SET
POINTER indicates time radio is to be turned on automati¬
cally.
2. Turn OPERATION SELECTOR to OFF and then to AUTO
position. Leave it in AUTO position.
3. Turn BEDTIME CONTROL clockwise to any period of
time from 0 to 60 minutes.
4. Tune in desired station and adjust volume.
APPLIANCE OPERATION
The APPLIANCE OUTLET is located on the rear of the
set. .Coffee-maker, heating pads, lamps, or any other elec¬
trical appliances which operate from 117 volt AC and do not
consume more than 1100 watts may be plugged into the AP¬
PLIANCE OUTLET. They will turn on automatically with
the radio.
To turn on the appliance automatically at some pre¬
determined time, follow the AUTOMATIC CLOCK-RADIO
OPERATION instructions. The radio will also come on
with the appliance, serving as a reminder that the appliance
has been turned on. If radio reception is not desired to¬
gether with appliance operation, just turn VOLUME knob to
minimum.
Appliances may also be operated manually, by following
MANUAL RADIO OPERATION instructions. If radio recep¬
tion is not desired with appliance operation, just turn VOL¬
UME knob to minimum.
If radio is to be used alone, be sure to remove appliance
plug from APPLIANCE OUTLET.
SERVICE NOTES
TO REMOVE RADIO CHASSIS FROM CABINET
1. Remove the four screws which hold the rear cover; dis¬
connect the antenna and appliance outlet leads and remove
the cover.
2. Pull off the two control knobs from the front of the cabi¬
net.
3. Remove the Phillips head screw under the tuning knob on
the front of the receiver.
4. Disconnect the chassis power leads from clock.
5. Disconnect speaker leads from chassis.
6. From the back, remove the three screws that mount the
chassis to the cabinet,
7. Remove the chassis from the cabinet.
TO REMOVE CLOCK FROM CABINET
1. Remove the two speaker mounting screws and remove
speaker.
2. Pull off the operation selector knobs on front of cabinet.
3. Remove the four screws that hold the clock bracket to
the cabinet.
4. Carefully remove the clock and clock bracket from the
cabinet.
5. Unsolder leads and remove the two small nuts and
washers mounting the clock to the clock bracket.
CLOCK REPAIR INFORMATION
Duplex timers can be repaired at Duplex Clock Co. , Inc.
29 Cherry Avenue, Waterbury, Connecticut.
The timer should be removed from the radio cabinet and
packed carefully in order that no further damage results in
shipment.
An acknowledgement with a quotation and a request for
payment will be sent to the dealer before the repair is made.
The timer will be returned to the dealer on receipt of pay¬
ment. If the timer is within warranty, repairs will be made
on a no-charge basis.
USE OF ISOLATION TRANSFORMER
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 rear cover is removed. When
servicing or aligning this chassis from AC, an isolation
transformer should be inserted between the power line and
the chassis.
CIRCUIT DESCRIPTION
1. The circuit of this chassis is conventional - there are
no built-in resistors or capacitors. Leads are plated on
both sides of the chassis base, thereby replacing the usual
connecting wires and making wiring more uniform.
2. The metal plating extends through all the holes on the
chassis, connecting circuits on the front with those on the
rear.
3. Reference to the schematic diagram and to chassis will
permit the circuit to be traced easily.
SAFETY PRECAUTIONS
1. Do not service the chassis on a metal plate, because of
the possibility of a short circuit.
2. Use caution when handling the chassis with power ap¬
plied, because all high voltage leads are exposed.
3. The outer edges of the chassis and various plated areas
are at ground potential.
COMPONENT REPLACEMENT
1. To prevent tube breakage, remove them before replac¬
ing components.
2. WHEN REMOVING DEFECTIVE COMPONENTS USE
ONLY A SMALL SOLDERING IRON (60 WATTS OR LESS)
TO AVOID DAMAGE TO THE 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. Plated connections or leads, if damaged, may be re¬
placed with a jumper of regular hookup wire.
4. It is recommended that multiple lug components be re¬
moved by immersing all the lugs simultaneously into a con¬
trolled temperature soldering pot. Motorola Part Number
66T632703. The component may then be lifted off the chas¬
sis easily. If a soldering pot is not available, heat each lug
individually with a small soldering iron and shake or brush
off as muchmolten solder as possible. Then, by alternately
heating and loosening each lug, the entire component will be
freed.
5. An individual tube clip may be removed by squeezing it
it with 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. Do not let the solder run onto an
adjacent lead, as a short circuit will be created.

ALIGNMENT
Use an isolation transformer between the power line and
the receiver. If not available, connect low side of genera¬
tor to ground (outer chassis edges) through a . 1 mf capaci¬
tor.
Connect a low range output meter across speaker voice
coil and set volume control to maximum.
Set signal generator output to produce .40 volts across
voice coil. As stages are aligned, reduce generator output,
to maintain the .40 volt level to avoid overloading receiver.
STEP
DUMMY
ANTENNA
GENERATOR
CONNECTION
GENERATOR
FREQUENCY
(400 cycle mod)
GANG
SETTING ADJUST REMARKS
IF ALIGNMENT
1 . . 1 mf
RF ALIGNMENT
. 1 mf
3 .
Grid of conVo
(pin 7, 12BE6)
Grid of conv 0
(pin 7, 12BE6)
Radiation loop*
455 Kc
1620 Kc
1400 Kc
Fully open
Fully open
Tune for max
1, 2, 3 & 4
(IF cores)
5 (Osc)
6 (Ant)
Adjust for maximum. Use
insulated screwdriver.
Adjust for maximum.
Adjust for maximum.
^Connect generator output across 5" diameter,. 5 turn loop and couple inductively to receiver loop. Keep loops at least
12" apart.
ALIGNMENT DATA
Front
1620 Kc
1400 Kc
12BA6 R8
Power
Interlock
c
]—
R1 C
I ■ T
3
¥
J
gsa \
50C5
»e ■
• _ . . ___

NOTE: When ordering parts, specify model number of set in addition to part number and description of part.
Ref. Part
No. Number
ELECTRICAL PARTS
Capacitors
Description
List
Price
Part
Number
MECHANICAL PARTS
Description
C-l
C-2
C-3
C-4
C-5
19K630263
8A120842
21R120853
23B630155
8K490232
Variable, 2-gang............ 2.85
Paper, tubular:
Ceramic Disc;
Electrolytic s
Molded, paper;
.05 mf 200V
.01 ml 450V.,
50-30 mf/150V
.047 mf 400V
.40
.25
1.90
.30
42B610632 Clip, tube pin.per/c
29A630230 Lug, terminal; AC connector...doz
28A631078 Plug, line cord (interlock)...,...
29A631120 Terminal, pin (on spkr & ant leads)
..... ,doz
CABINET PARTS
CR-1 21B630180
E-l
72D632676
L-l *1V632714
L-2 24B630327
LS-1 50C630287
or 50C631455
Resistors - Note:
Multiple Capacitor Resistor
Plate......................
Clock Assembly; Duplex
NOTE: SEE SERVICE NOTES
FOR CLOCK REPAIR INFORMATION
Antenna Loop & Back Cover
Assembly: incl AC recept &
line cord............... ■
Coil, oscillator......... t
.85
3.70**
.85
Speaker, PM; 4"; 3.2 ohm
VC; incl T-3.. 4.70**
exch 3.55
All resistors are insulated carbon
type unless otherwise specified
*16K632657
♦ 1 6K632659
*16X632660
*16K632661
30B630227
61A622114
♦ 36K632662
*36X632663
*36X632667
*36X632668
*36X632665
*36X632666
1V630275
*34X632664
mahogany (55C1)
white (55C2)...
mint green
Cabinet, plastic:
Cabinet, plastic:
Cabinet, plastic:
(55C3)....
Cabinet, plastic: clover pink
(55C4)....
Cord, line: with plug
recept ...
Crystal, plastic.........
Knob, operation selector:
(55C1,3,4).....................
Knob, operation selector: white
(55C2) .
gray (55C1,3,4),. . .
white (55C2).......
gray (55C1,3,4)....
white (55C2).......
with lugs.
interlock
gray
a O • • «
Knob, tuning:
Knob, tuning:
Knob, volume:
Knob, volume:
Receptacle, appliance:
R-l
6K119405 22,000 20% 1/2W.. ,
« « « •
.doz
1.20
3S115138
R-2
6K119407 3.3 meg 20% 1/2W.
• 0*0
.doz 1.20
R-3 6K119402
100 20% 1/2W.
P • O •
.doz 1.20
R-4
6K119407 3.3 meg 20% 1/2W.
o • o o
.doz 1.20
3S121050
R—5 18A630279
Volume Control: 1
meg.
« « o «
.95
R-6 6K119403 150 20% 1/2W ... , .
O 0 0 0
,doz
1.20
R-7
6K121276
1000 20% 2W......
• OOP
.25
3S115237
R-8
6B119401
27 10% 1/2W......
o o o •
.doz
1.20
15A630871
T—1
♦ 2 4K632782 Trans, 1st IF: 455
Kc. 1.40
31A630229
T-2
24K632039 Trans, 2nd IF: 455
Kc. 1.30
T-3 25B630280 Trans, output......
• • • •
1.00
29A620057
PRICES SUBJECT TO CHANGE WITHOUT
♦ New Item , Appears in any List for !
Scale, clock dial.,..,..,......,..
Screw, machine: 6-32 x 1-9/16
Phillips flat head (chassis mtg -
through front of cabinet)....»doz
Screw, thread-cutting: #% x 1/2
plain hex head (chassis & spkr
mtg)..........................doz
Screw, thread-cutting: #6 x 5/16
plain hex head (clock mtg)....doz
Shell, appliance recept mtg..,.,,.
Terminal Strip (AC connector on
clock mtg brkt)..................
Terminal, pin (on ant loop leads)
..............................doz
**Plus Federal Excise Tax at Current Rate
***Prices Furnished Upon Request
List
Price
.50
.35
.10
.20
***
***
***
***
1.35
.15
.15
.15
,25
.25
.15
.20
.35
.60
.20
,25
.40
.05
.25
.25