Heathkit GR-61 User manual

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FM PORTABLE RADIO
MODEL GR.6I
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TYPICAL COMPONENT TYPES
This chart is a guide to commonly used types of elec- tions should prove helpful in identifying most parts and
tronic components. The symbols and related illustra- reading the schematic diagrams.
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RESISTOR
aAA/v!- ffi ;l^"o"'-o"Rr@ PLATE
SUPPRE$OR
lilo'* ruBE
CATHOOE
F ILAM EN T
POTENTIOMETER
( coNrRoL )
cELECTROLYTIC
CAPACITOR
+ll-
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COLLECTOR
TRANSISTOR
EMITT ER
COLLECTOR
EM ITTER
m
f-lpaxsroRuER
f'..'o"'| RECTIFIER
(DloDE)
c-emi":,l3PER <>
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Lrh'i^H'$*nM
BATTERY
Il- NEON
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PHONO
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lf
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PHONE
JACK
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(colL) RECEPTACLE
q--{> sPsT .swlrcH -
( TOGGLE )
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DPDT
nlF''39!+fI^'fl S PEAKER 'd swrTcH
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BINDING
POST t
M ICROPHONE FUSE
ANTEN NA
GENERAL LOOP
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EARTH GROUND
CHASSIS GROUND
CONOUCTORS

Assembly
and
Operation
of the
FM
P O RTAB LE
RAD IO
MODEL GR-61
'===*=,
HEATH COMPANY
BENTON HARBOR,
MICHIGAN
TABLE OF CONTENTS
Specifications. . . .
Introduetion.
Circuit Description.
Parts List.
Step-By-Step AssemblY
Circuit Board AssemblY. . .
Right End Plate Parts Mounting.
Left End Plate Parts Mounting.
Circuit Board Mounting. . .
Wiring Circuit Board To End Plates. . ..
Final Wiring
Final Assembly. . .
Initial Test And Adjustment. . .
Cabinet AssemblY.
Operation.
In Case Of DifficultY
Troubleshooting Chart.
Introduction To Transistors. . .
Glossary Of Radio Terms.
Circuit Board X-RaY View.
(fold-out from Page). . . . .
Cqyrlghto t962 12/3O/66
2
3
3
D
30
31

SPECIFICATIONS
Tuning Range.
Intermediate Frequency (IF'). . .
Sensitivity.
Controls.
Transistors.
Antenna.
Speaker.
Batteries.
Normal Battery Life. .
Accessory Jack. .
Size. .
Net Weight.
The Heath Company reserves the right to discon-
tinue instruments and to change specifications at
any time without incurring any obligation to
88 to 108 megacycles.
10.7 megacycles.
3 uv for 20 db quieting (average), 5 uv for 20
db quieting (maximum). (Measurements takenin
aligned condition. )
Volume, Tone, and AFC.
3 - 2N174?
4 - 2Nt274
1 - 2N24e5l
1 - 2N26711 in FM tuning unit
1 - 2N26541
Collapsible whip with provisions for external
300 Q antenna.
4r x 6t' oval, permanent magnet type.
Six l-l/2 volt size C cells.
300-500 hours.
Earphone or hi-fi output.
9-L12" wide x 1-l/Q,,high x 4" deep.
3 lbs.
incorporate new features in instruments pre-
viously sold.
I*
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INTRODUCTION
Your new FM Portable Radio featuresadepend-
able 10-transistor circuit, housed in an attractive
imitation-leather case. The front of the case is
made of durable high-impact plastic.
Exceptionally high quality is designed into this
Radio, as evideneed by ttre preassembled and
prealigned FM tuning unit, and the prealigned
IF and ratio detector transformers. -ThreJIF-
limiter stages, plus a ratio detector combina-
tion with AFC, provide stable FM reception. The
push-pull audio power amplifier circuit delivers
more than adequate power for the 4" x 6"
speaker to give large-room sound coverage.
CIRCUIT DESCRIPTION
The preassembled and prealigned FM tuning
unit contributes to ease of assemblyandinsures
consistently good FM performance. A heavy-
duty circuit board is used to further simplify
assembly of the kit.
If you are not familiar wlth electronic circuitrv
and terminology, you may find it helpful to reai
the I'Introduction To Transigtorsr and "Glossary
Of Radio Terms" beginning on Page 2? of ttre
manual. This information should prove helpful
in understanding how your Radioworkswhenyou
read the following Circuit Description.
The circuitry of the FM Portable Radioconsisrs
of the RF, IF-limiter, ratio detector, and audio
sections. For simplicity, each section will be
discussed separately, Refer occasionally to the
Schematic Diagram while reading tris descrip-
tion.
To help in reading the Schematic, the letter-
number designations for t}e circuit parts are
number coded as follows: #1 to gg for the FM
tuning unit, and #100 to 200 forthecircuit board
and chassis. For example, resistor R3 ig in the
FM tuing unit, and resistor R,103 is onthe cir-
cuit board.
NOTE: Refer to the "Kit Builders Guide" for
complete information on unpacking, parts identi-
fieation, tools, wiring, soldering, and step-by-
e
RF SECTION
The RF section contains the RF amplifier,
oscillator, and mixer stages, all in i pre-
assembled and prealigned tuning unit.
FM signals from the antenna are applied to
transformer T1 , which matches the antenna to the
first section of the tuning capacitor, C1A. This
portion of the tuning capacitor tunes ttre emitter
circuit of RF amptifier Ql to the desired FM
station frequency. C1B, the second section of tlte
tuning capacitor, tunes the collector circuit of
Q1 to the same station frequency.
Q2 is operated as a feedback tuned-collector
oscillator at 10.? megacycles above the fre-
quency of the desired FM station. The ampli-
fied FM station frequency from Q1, and the
oscillator frequency from Q2 are mixed in Q3
to provide a difference frequency of 10.7 meg-
acycles. This difference frequency is coupled
tirough transf orme r T2, out of the preas se mble d
tuning unit, to the first IF amplifier, Q4.
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The circuit of the P.E.C. includes a de-empha-
sis network to compensate for high frequency
pre-emphasis that was added to the transmitted
audio signal; it thus provides a flat audio fre-
quency response. This network also attenuates
frequencies above the audio range.
The audio output signal of the ratio detector is
applied both to Q7, the emitter follower and, as
an AFC voltage, to Q2 oftheFMtuning unit. Any
shift of the IF from the 10.7 megacycle center
frequency appears as a DC voltage which is ap-
plied to diode D1; this is commonly called AFC
voltage. The DC voltage shift on D1 in turn
changes the oscillator capacity, thereby ef-
fectively retuning it and causing it to track the
particular station that is being received.
AUDIO SECTION
The audio signal from the ratio detector is
applied to Q7, the emitter follower, which acts
as a matching networkbetween the ratio detector
and the Volume control. After the Volume control,
the audio signal is amplified bydriver amplifier
Q8 and then to the Tone control and to driver
transformer T6. Transformer T6 couples the
audio signal to Q9 ahd Q10, ttte push-pull audio
amplifier stages. From Qg and Q10 the signal,
is coupled to the speaker and earphone jack
through T?, the audio output transformer. When
an earphone is plugged in, the built-in speaker
is automatically disconnected from the circuit
and the audio signal goes instead to the ear-
phone.
Operating power is supplied by six 1-1/2 volts
size C flashlight batteries.
IF-LIMITER SECTION
The 10.? megacycle signal from the FM tuning
unit is appliedto Q4, the first IF amplifier. From
Q4, the IF signal passes through transformer T3'
which passes only the difference frequency of 10.?
megacycles, to Q5, the second IF amplifier. After
additional amplification in Q5, the signal is
applied through T4, the second IF transformer,
to limiter stage Q6, which limits on all but the
weakest signals.
Stages Q4 and Qb act as IF amplifiers for weak
signals, and as limiters for strong signals.
Limiter stages are used to remove any AM
(amplitude modulation) of the IF signal, and to
limit the signal to the proper level for the ratio
detector. The IF signal from limiter Q6 is next
applied to ratio detector transformer, T5.
RATIO DETECTOR
Ideally, the IF signal applied to the ratio de-
tector should be of constant amplitude, but con-
tain variations in frequency which correspond to
tfie audio signal being transmitted by the FM
station. The amount of frequency deviationfrom
the center frequency of 10.7 megacycles de-
termines the amplitude of the resulting audio
signal. The number of times per second thatthe
IF signal deviates from 10.? megacycles de-
termines the resulting audio frequency. The
combinatlon of diodes D3, D4, and transformer
Tb detect frequency variations in the IF signal,
and change these variations into anaudiosignal.
Most of the resistors and capacitors used inthe
ratio detector are encapsulated in a P.E.C. (pack-
aged electronic circuit). The use of this P.E.C.
eliminates any variations in performance that
could result from different wiring techniques.

@EE@l P"e"s
PARTS LIST
The numbers in parentheses in the Parts List
are keyed to the numbers in the Parts drawings
to aid in parts identification.
PART
No. PARTS
Per Kit DESCRIPTION
4.7 Q (yellow-violet-gold)
10 Q (brown-black-black)
68 A @Iue-gray-black)
220 Q (red-red-brown)
820 A (gray-red-brown)
1 KO (brown-black-red)
1.2 KO (brown-red-red)
2.? KO (red-violet-red)
3.3 KO (orange-orange-red)
4.1 KA (yellow-violet-red)
6.8 Kft (blue-gray-red)
10 KO (brov'n-black- orange)
t2 KQ (brown'red-orange)
15 KO (brown-green-orange)
18 KO (brown-gray-orange)
22 KA (red-red-orange)
68 Kf) (blue-gray-orange)
1 00 KO (brown- black- yellow)
1 megohm (brown-black-
green)
PART PARTS
No. Per Kit
Controls-Switch
(5) 10138- 1- "
(6) 1e-81
(?) 60-18 1
Choke- Transf ormers- Diode
DESCRIPTION
100 KO linear control
10 KQ control with SPST
switch
SPST switch
Resistors
(1) 1:T20
t-4L
L-2
t-45
1-8
1-9
1- 10
1- 13
t-r4
1- 16
1- 19
L-20
1-109
L-21
1-69
t-22
1-60
r-26
1- 35
Capacitors
(2)2 -
2t-46
2t-94
(3) 25-54
(4) 25- 11 5
25-116
25-tl?
25-11 1
(8) 45-35
(e) sr-sz
51-98
(10) 52-57
53-6
(11) 56-26
(81
(10)
2
1
1
2
1
I
1.? ph choke
Driver transformer
Output transformer
IF transformer
Ratio detector transformer
Crvstal diode
1
I
I1
4
I
2
1
210 ttttf disc ceramic
.005 pfd disc ceramic
.05 pfd disc ceramic
10 pfd 15 V tubular electro-
lytic
10 pfd 15 V electrolytic
50 pfd 15 V electrolytic
100 pfd 15 V electrolytic
1000 pfd 15 V tubular elec-
trolytic
tzt 1-7
\\=t-/-
{4r lf-----------v
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PART
No. PARTS DESCRIPTION
Per Kit PART
No. PARTS DESCRIPTION
Per Kit
Transistors
4t7 -10 1
411 -7t 1
411 -72 1
411 -57 3
tt7-2 1
2N2671 transistor
tuning unit)
2N2654 transistor
tuning unit)
2N2495 transistor
tuning unit)
2Nl74? transistor
Transistor package contain-
ing four part no.417-21, type
2N1214 transistors
3-48 x 1/4" screw
4-40 x 1/8" setscrew
6-32 x 3/16" screw
6-32 x l/4" screw, phillips
head
6-32 x L/4" sctew, binder
head
6-32 x 3/8" screw
6-32 x 3/8" self-tapping
screw
6-32 x l/2" screw
(in
(in
(in
Hardware (cont?d.
FM (18) 254-? I
(1e) 254-e 2
FM (20) 254-1 1
(2r) 254-14 2
FM (22)254-4 1
#3 lockwasher
#4 lockwasher
#6 lockwasher
Small control lockwasher
Large control lockwasher
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Hardware
(1) 250-4e
(2) 250-156
(3) 250-138
(4) 250-22s
(5) 250-56
(6) 250-8e
(?) 250-106
(8) 250-10
343-?
344-50
344-1 6
344-t5
346-1
[ ] ${ilrlr (2) fo (3} frfril ro flinm ,rr,-rz+rQ2
,-,F (16)@ e7l I
^ (5) ^ (61 ^ (71 , (8)
fl,',ii',',i l,p,i,'*rr gF** t}.**t
I
2
8
3
d
2
n
4
@
@
4
2
1
1
2
4
10
4
2wire
wire
wire
(s) 252-r
(10) 252-15
(11) 252-3
(L2) 252-22
3-48 nut
4-40 nut
6-32 nut
6-32 speednut
(ls)
@(16)
(l z1 @
g
(r a1 (l e) (20) (21 ) ezl
@@@@@
. r3) 255-11
(24) 25e-rt
(25) 25e-12
(26) 455-31
(2?) 258-30
Metal Parts
(Zg) tOO-rr,rarO r
(2e) 1oo-M41? 1
(30) zo4-Mb1? 1
Cable-Wire-SleevinE
Tapped spacer
Spade lug
Large solder lug
Antenna bushing
Battery spring
Length shielded cable
Length black hookup
Length stranded red
Length stranded black
Length sleeving
Switch lever
Bottom circuit board bracket
Top circuit board bracket
ota:lno)g rlr). urt&
Small control nut
Large control nut
Flat washer
Thin nylon shoulder washer
Thick nylon shoulder washer
(13)
(14)
(13) 252-3e
(r4) 252-7
(15) 253-45
(16) ?5-18
(1?) 2b3-Eo
3
1
2
1
I

r* Page T
PART
No. PARTS DESCRIPTION
Per Kit
Metal Parts (cont'd.)
(1) mA:IFI0--T------Tntenna bracket
(2) 205-M391
(3) 205-M392
(4) 46e-Ml3
85-51F831
92-9
93-8
110-14
391 -23
401-19
(6) 431 -6
(?) 434-110
(8) 436-16
462-81
462-r8r
462-89
462-175
490-1
490 -2 3
tr42-42
390 -1 58
(e) 214-30
(10) i214-31
(1 1) ?3-4?
331 -6
595-593
Right end plate
Left end plate
Batterv contactor
1
1
1
I
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1
1
I
1
1
1
7
I
1
I
1
2
1
1
1
1
1
2
3
1
P.E.C. (packaged electronic
circuit)
Circuit board
Cabinet front
Leather case
FM tuning unit
Nameplate
Spealer
2-screw terminal strip
Transistor socket
Earphone jack
Small tuning larob
Large tunlng knob
Volume knob
Tapered knob
Alignment tool
Allen wrench
Collapsible antenna
Battery label
Battery holder
Battery holder end
Sponge rubber pad
Solder
Manual
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_.-TOP SIDE
,f NOTE: SOCKETS MUST
@@
11. ( ) Conn
AFC.
circr
( ) Referring
length of
CUT THE CAE
BELOW. PRE
TAKING CAR€
OF THE SHIEI
INSULATION.
PEEL OFF TI'
THIN WIRES (
Defoi
Detoil lA
dj, BE INSERTED FROM
THE TOP (LETTERED}
SIDE OF THE CIRCUIT
BOARD. THIS IS THE
SIDE OPPOSITE THE
METALIC FOIL.
,,1,::
ir
REMOVE THE
SMALL IYIRES
AMOUNTS OF
LEAD ANO TH
SOLDER --{
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w'ire
(s-1)
othe:
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may
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KEYWAY

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Detqil lC
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Page 8
Before starting
Builders Guide
wiring, solderit
procedures.
CIRCUIT BOARI
( ) Referring t
mount the I
circuit boal
lettered si<
socket Posi
of the circu
align ProPe
all four Pir
lrcard. Be r
unused hole
( ) Referring
tapped spa
the circuit
These spac
keep it le'
rePositione
Proceed to Pic
steps surroundi
Refer to Picto
( ) Remove th
lettered sit
them on th
using tlte s
PICTORIAL 3
PICTORIAI I
PROCEED TO PICTORIAL 2

STEP.BY.STEP ASSEMBLY |@E
11. ( )c
A
ni
Before starting to assemble this kit, readthe Kit
Builders Guide for complete information on
wiring, soldering, and step-by-step assembly
procedures.
CIRCUIT BOARD ASSEMBLY
( ) Referring to Detail 1.{ (on Pictorial 1),
mount the seven transistor sockets on the
circuit troard. Insert the sockets from the
lettered side of the board. Be sure each
socket positioning tab fits into the keyway
of the circuit board, and thatthe socketpins
align properly with the foil pattern. Solder
all four pins of each socket to the circuit
board. Be careful not to solder any of the
unused holes in the circuit board.
( ) Referring to Detail 18, mount the four
tapped spacers on the lettered side of
the circuit board. Use 6-32 xg/g,,screws.
These spacers will support the board and
keep it level. They will be removed and
repositioned later.
Froceed to Pictorials 1 and 2 and perform the
steps surrounding the illustrations.
Refer to Pictorial 3 for the following steps.
( ) Remove the four tapped spacers from the
lettered side of the circuit board. Then mount
them on the foil side of the circuit board
using tlle game screws.
PICTORIAL 3
NOTE: When using hookup wire in the following
steps, cut the required length of wire and strip
l/4 of. insulation from each end.
Connect one end of thefollowingwirestottre eir_
cuit board. The correct length is given at the
beginning of each step. The free ends of tlese
wires will be connected later.
1. (
2.(
3.(
4.(
5.(
6.(
t. \
8.(
e.(
10. (
)5"
)3"
)2"
) 4-t/4"
)4"
) r-3/4,'
I L-3/4"
) 3-r/2,,
)2"
) 2-3/4"
LENGTH FROM
TONE-3 (S-1)
vol-z (s-1)
vol-1 (s-l)
TONE-1 (S-1)
TONE-2 (S_1)
BATT + (S-1)
vol-3 (s_1)
AFC-z (S-1)
rF - (s-1)
IF + (S-1)
( ) Referr
Iength
CUT THE
BELOW. I
TAKING C,
OF THE SF
INSULATII
PEEL OFF
THIN WIRI
REMOVE TI
SMALL WIF
AMOUNTS (
L E A D A ND
SOLDER
12.() At
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11. ( ) Connect a 4-3f4,' wire between points
AFC-1 (S-1) to AFC-I (S-1) on tne
circuit board. Position as shown.
( ) Referring to Detail 3A, prepare a J-t/Z',
length of shielded cable as shown.
12. ( ') At oneendofthecable.connecttheinner
wire to AGC (S-1) andtheshieldtoGND
(S-1) of the circuit board. Leave tlre
other end free. Be careful not to over-
heat the cable conductors since this
may cause the inner insulation to melt,
resulting in a short circuit. Grip the
leads with pliers between the solder
connection and the insulation.
13. ( ) Remove l/4t' of insulation from each
end of a 9" Iength of stranded black
wire. Twist the separate strands to-
gether tightly at each end of the wire.
Then apply a small amount of solder
to each end toh6iTifre strands tosether.
( ) Connect one end of this g" black wire to
BATT- on the circuit board (S-1). The other
end will be connected later.
14. ( ) RFC-1. Cut one lead length of a RF
choke (#45-3b) to 1", place B/4,' of.
sleeving over this lead and connect it
to RFC-I on the circuit board (S_1).
Leave the other end free.
( ) Ctip off all excess leads at the soldered
joints on the foil side of the circuit board.
NOTE: When mounting transformers in the fol-
lowing steps, carefully align the pins of each
transformer with the holes of the circuit board.
The spacing of the transformer pins and the holes
of the circuit board are such that when alisned
properly ttrey will mount easily, withoutforJing.
15.()
16.()
1?.()
T7. Install the outputtransformer (#b1-
98) at T?. Solder all 5 pins.
T6. Install the driver transformer
(#51-97) at T6. Solder all 5 pins.
T3. Install one of the IF transformers
(#52-51) at T3. Solder all 8 pins.
18, ( ) T4. Install the remaining IF trans-
former (#52-51) at T4. Solder all 8 pins.
19. ( ) T5. Install the ratio detector trans-
former (#53-6) at TF. Solder all?pins.
( ) Check to see that all the connections made
on the circuit board have been soldered.
Set the board aside temporarily.
ll
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CUT THE CABLE ACCORDING TO THE DIMENSIONS
BELOW. PREPARE EACH END A5 SHOIVN.
IAKING CARE NOT TO CUT THE VERY THIN WIRES
OF THE SHIELD LEAD, REMOVE THE OUTER
INSULATION.
PEEL OFF THE FOIL AND STRAIGHTEN OUT
THIN WIRES OF THE SHIELO LEAD.
REMOVE THE INNER INSULATION AND TIVIST THE
SMALL IYIRES OF THE SHIELO LEAD. APPLY SMALL
AMOUNTS OF SOLDER TO THE ENO OF THE SHIELO
LEAO AND THE INNER LEAO.

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Page 10
6-32 SPEEDN
FLAT SIDE
6-32 NUT-\
LOCKWASH ER -
T ER MIN/A
RIGHT END PLA'
Refer to Detail
( ) Mount two 6-
plate. Be surr
is positioned
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Deloil 1F
PICTORIAT

6-32 X3lt6"scREW
6-32 SPEEDNUT
AFC SWITCH
*T 6 LOCKWASHER
6-32 NUT
THIN NYLON
SHOULOER WASHER
AN TE NNA
BUSHING
SOLDER
SMALL CONTROL
T HICK NYLON
SHOULDER WASHER
RIGHT END PLATE PARTS I,IOUNTING
Refer to Detail 44, for tfie following steps.
( ) Mount two 6-32 qreeftruts on &re right end
plate. Be sure ttre flat side ofeachspeednut
is positioned as shown.
Detdil 4A
Mount the antenna bracket to the end plate.
Use 6-32 x 1/4"binder head screws, #6 lock_
washers, and 6-32 nuts.
Mount the 2-screw terminal strip to the
antenna bracket. Position it as shown. Use
6-32 x 1/4" binder head screws. #6 lock_
washers, and 6-32 nuts.
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( )Mc
bri
thi
slr
sol
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( )Mc
an(
pol
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#6
Set thr
LEFT E
Refer
( )Mo
RIGHT END PLATE
6 -32X1/4'
B IN OER
/^(t\ v i
VorurEN*e
BRAC KET
TERMINAL STRIP
6-32xt/4 BTNDER
HEAD SCREW

@EE@l Pagell
TROL NUT
CONTROL NUT
LEFT ENO PLATE
LARGE
CONTROL LOCKWASHER
VOLUME CONTFIOL
Detqil 48
EAFIPHONE ,O.**ffi
TONE CONTROL
( ) Mount the antenna brtrshing to the antenna
bracket. Use the thicknylon shoulder washer,
thin nylon shoulder washer, solder lug, and'
small control nut. position and ben-d the
solder lug as shown. Tighten securely with a
Iarge screwdriver.
( ) Mount the AFC switch with #4 lockwashers
and 4-40 nuts. Be sure the switch lugs are
positioned as shown. See pictorial 4.
( ) Mount the preassembled FMtuningunitwith
#6 lockwashers and 6-82 x B/16n screws.
Set the right end plate aside temporarily.
LEFT END PLATE PARTS MOUNTING
Refer to Detail 48 for the following parts.
( ) Mount two 6-32 speednuts on the left end
plate. Be sure the flat side ofeachspeednut
is positioned as shown.
( ) Mount the Volume control (#19-g1) with a
large control lockwasher and large control
nut. Position th€ lugs as shown.
( ) Mount the Tone control (#10-1gg) with a
small control lockwasher and small control
nut. Position the lugs as shown.
( ) Mount the earphone jack with a small con-
trol loekwasher and small control nur.
Position the lugs as shown.
Set the left end plate aside temporarily.

CIRCUIT BOARD MOUNTING
Page 12
Refer to Detail 4C for the following steps.
( ) Prethread the endholes ofthetopahdbottom
circuit board brackets with a-O-gZ xg/g,,
self-tapping screw.
( ) Mount the eircuit board to the tqp and bottom
brackets. Use B-49 x L/4,, screws. #3 lock_
washers, and B-4g nuts. Do not tighten the
serews.
( ) Re^ferring to Detail 4D, mount the right and
left endplates to the top and bottorn brickets.
Use 6-32 x 3/16" screws. position the
screws to the rear (away from the flange)
of the slotted holes in the end plates ind
tighten. Now tighten the sereu/sthatholdthe
circuit board to the top and bottom brackets.
WIRING CIRGUIT BOARD TO END PLATES
Refer to Pictorial 4 (fotd_out trom nage tO)
for the following steps.
Conhect the free endg of the wires comins from
the circuit board to end plate terminils as
directed in the folloWlng steps:
( ) Connect a .05 pfd digc ceramic capacitor
from lug 4 (S-2) to lug 1 (S-2)- of the
Volume control.
FROM CIRCUIT
BOARD POINT
( ) eart+
( ) TONE-2
( ) vol,-l
( ) vol,_z
( ) roNE-l'
( ) roNE-3
( ) vor,-s
( ) Arc-2
( )tr-
( )rr+
TO
lug 4 of Volume eontrol (NS).
Itig 2 of Tone control (S-1).
lug 1 of Volume control (NS).
lug 2 of Volurne control (S.1).
lug 1 of Tone control (S-1).
lug 3 of Tone control (S-1).
lug 3 of Volume control (S_l).
lug 2 of AFC switch (NS).
IF- of FM tuning unit (S-1).
IF+ of FM tuning unit (S-1).
3-46 x thil scREw
Detoll 4c

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I
6-32x 3,/t6rscREW
COMPONENT
SI DE
{
( ) at the free end of the shieldedcablecoming
from the circuit board, connect the inner
conductor to AGC (S-f) anO the shield to
GND (S-1) of the FM tuning unit. Grip the
inner conductor and shield between the
insulation and the solder connection with
long-nose pliers to prevent heat damage to
the insulation.
( ) Connect the free lead of choke RFC-1 to
AFC-1 of the FM tuning unit (NS). Use
sleeving.
( ) Connect a Bil wire from AFC_2 on the FM
tuning unit (S-f ) to lug 2 of ttre AfC s*ii"r,
(s-2).
( ) Connect a 3-L/4,, wire from AFC_1 of the
rM luqing unit (S-2) to lug 1 of the AFC
switch (S-1).
NOJ| : Where a wire goes through a connection
ancl men goes to another point, as in the next
step, it will count as two wires inthe solder in_
.i15t1ctio1q (S-2), one entering and one-leaving
me connection.
( ) Connect one end of a Z-g/4,,wire to ANT_I
ot$9 r{i tuning unit (S_1).Strip !/2,,o! in_
sulation from the other end ot tiis wireand
pass the wire through the solder luE at ihe
antenna bushing (s_2) to AltT_l of the Z_
screw terminal strip (S_1).
) Connect a 3-L/4,, wire from ANT-2 of the
2-screw terminal strip (S-1) to aNT_?oi
the FM tuning unit (S-i).
) Place a 2" length of sleeving on the plus
(+) lead of thJ 1000 pfd tub-ular eteciro_
lytic capacitor (#2b-111). Bend ttris-feaa
down against the side of the capacitor as
shown.
) Mount the capacitor to the circuit board
by placing the lead from the negative ;nJ
into the f ) hole of the circuit board. place
the plus (+) lead into the (+) hole ot tt e ci"_
cuit board. Solder both leads to t}e circuit
board and clip off the excess wire.
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