Sony TFM-8100W User manual

Circuit System:
Frequency Coverage:
Intermediate Frequency:
Antenna System:
Maximum Sensitivity
Selectivity
at t10 kHz off-resonance:
Power Output
at 10% distortion:
maximum:
at 50 mW output:
SPECIFICATIONS
15-transistor (including 1-FET) super-
heterodyne,
1 transistor for auxiliary circuit,
and 7 diodes (including 1 LED)
FM 87.5 ~ 108 MHz (3.43 m ~ 2.78 m)
AM 530 ~ 1,605 kHz (566 m ~ 187 m)
VHF WB 162.55 MHz (1.85 m)
FM 10.7 MHz
AM 455 kHz
VHF WB 10.7 MHz
FM, VHF WB built-in telescopic
antenna
AM built-in ferrite bar
antenna
FM 1.25uV (2dB)
Mw 35.4uV/m (31 dB/m)
VHF WB) O.8pV (-2dB)
26dB at 1,400kHz
650 mW
WwW
Current Drain
at zero signal:
at 10% distortion:
Power Requirement:
AUX IN Jack
impedance:
MPX OUT Jack
impedance:
level:
Record Out Jack
impedance:
level:
Speaker:
Dimensions:
Weight:
FM 23mA, AM 19mA
300 mA
Three ‘’C’’ size flashlight batteries
4.5V in total, or
car battery by using SONY DCC-126
car battery cord.
5kQ
5kQ
-26 dB (38 mV)
1kQ
~60 dB (0.77 mV)
334” (9 cm) ¢, PM dynamic, 82
876" (W) x 7° (H) x 2346" €D)
(214mm x 178mm x 56nm)
2lb 150z (1,350g)
SON Ys
SERVICE MANUAL

FM-8100W -
TABLE OF CONTENTS
Section Title Page Section Title Page
Specifications ..........ccccccseeccceeeseccesceeeesereees 1 3-3. Voltage and Current
Adjustment .........cccccccceeceeseeeeeeeeaee 11
1 OUTLINE 3.00) chescdecssdet aheel chess eckedeceittents 2
1-1. Block Diagram 2.0.0.0... cee eeeeeeeees 2 4. MOUNTING AND SCHEMATIC
1-2. Circuit Description ....cccccccecccceeceooeee 3 DIAGRAMS) ssi. ieee ead 12
1-3. External View ..........cccceceeceeseseerenes 4 4-1. Resonance Indicator Circuit
1-4. Internal View .........cccceesccceeceeeeeeeees 4 Board ...2.c.siccccsseccssesesouasdiveestuedestect 12
4-2. Vhf WB Tuner Circuit Board....... 12
2. DISASSEMBLY ..............ccccccceeceeeeseeeesenees 5 2° “Main Gack Board
2-1. Rear Cabinet Removal ...........cceee 5 — Conductor Side — ................ 13
2-2. Chassis Removal Gutiosececaeceuetvesersieeress 5 4-4, Schematic Diagram ae Nibit sb neh 15
2-3. Printed Circuit Board : 4-5, Main Circuit Board
Removal sis iiickteecisteeatdstistete ined 6 — Component Side — .......... 17
2-4. Whf WB Block Removal.............. 7
2-5. Dial Cord Stringing .......ccecceeeee 8 S. EXPLODED VIEW AND PACKING ..... 19
3. CIRCUIT ADJUSTMENTS ...0..2...c.cssee. 8 5-1, Exploded View (1) -....sssseeeeoen 19
; 5-2. Exploded View (2) ..... cc eeeeees 21
3-1. Lf Alignment ....-ssesseessssseesseeseesseeey 8 5-3, Packing ..c.cecccccccsecsseceseseessecesscescaees 23
3-2. Frequency Coverage and
Tracking Adjustment .................05 10 6. ELECTRICAL PARTS LIST ................. 24
SECTION 1
OUTLINE
1-1. BLOCK DIAGRAM
OTEL ANT
| FM IF AMP 3 FM IF AMP 4 FM IF AMP 5
FM RF AMP FM CONV FM IF AMP 1 FM IF AMP 2 AM CONV AM IF AMP 1 AM IF AMP 2 FM IF AMP 6 FM DET
AFC
aot Q02 Q04 Qos Q06 Q07 Q08 DO5, 06
280710 2SK23 2SC710 2SC710 2SC710 28C710 28C710 1726
TCH
RF AMP MIX
0202 Q201 p04
Q101 Q102 GPR-1 28C633 18426
'
2SC668 2SC710 ; AGC
Q03
280710
AMIDET.
WG
POWER
AMP
VHF]
WB
We
iF
OSC
ii
AF
AMP
1
AF
AMP
2
BAR
ANT
2SB495
0103
Q0g9
Qio
|
SP
28C710
28C870
2SC870
O12
2SB495
POWER
AMP
NFB
Note:
LED;
Light
Emitting
Diode
Fig,
1-1

1-2. CIRCUIT DESCRIPTION
7. Resonance-Indicating Circuit
The model TFM-8100W resonance-indicating
circuit uses an LED (Light Emitting Diode).
i-f
section
Fig. 1-2
The circuit is shown in Fig. 1-2. Resistors
R201, R202, R203, and diode D201 keep a constant
bias voltage (VB) on the base of Q201. The bias is
set at the cut-off point of Q201. Here, D201
stabilizes the bias against a variation in source volt-
age or temperature.
ZERO collector current flows at no input signal,
but the transistor has a high sensitivity to an input
signal. When an i-f signal (of 455 kHz or 10.7 MHz)
is added to the base, collector current flows in pro-
portion to the signal strength. Thus, the LED (D202)
is illuminated by the collector current.
Ic Q201 |C ~— VB curve
~ illumina ting
current
—-—at ZERO signal
VB
Fig. 1-3
2, VHF WEATHER Tuner
In the model TFM-8100W, the local oscillator for
the vhf weather band uses a crystal resonator XTAL
as shown in Fig. 1-4 to obtain stable reception of
vhf weather broadcasting. The resonant frequency
of the crystal oscillator is 57.75 MHz. Transistor
Q103 uses the 57.75-MHz signal on its base to
TFM-8100
produce harmonic components at its collector.
Resonant circuits which contain inductor L104 and
capacitor C114, or L103 and C115 are connected to
the collector of Q103 and are tuned to resonance at
the third harmonic (173.25MHz). Transistor Q102
mixes the vhf weather band signal (162.55 MHz) and
local oscillator signal (173.25MHz) at its base
and applies the resulting intermediate frequency
(10.7 MHz) to the i-f stage.
to the base
of Q102
(+) B
= VHF WB
osc coil
Fig. 1-4
—— Hardware Nomenclature
~ Pan Head Screw
— Pan Head Screw
with Spring Washer
Round Head Screw
Flat Fillister Head Screw
Set Screw
Retaining Ring (E Washer)
W -—- Washer
SW — Spring Washer
LW — Lock Washer
N — Nut
— Example —
— Type of Slot
@ P 3x10 = -
re i
|
Lengthinmm(L)
1
L
Diameter
in
mm
(D)
hg
:
1.
|
Type of Head

FM-8100W
1-3. EXTERNAL VIEW
~ Front View —
1-501-124-12
telescopic antenna
X-38376-84-0
left side cover ass’y
3-837-623
knob, VOL control
3-837-624
knob, TONE control
X-38376-8 1-2
front cabinet ass’‘y
— Rear View —
3-837-803
specification label
X-38376-82-2
rear cabinet ass’y
3-837-809 .
label, instruction
1-4. INTERNAL VIEW
1-401-429-
coil, ferrite bar
antenna
3-837-619
drum, dial
1-151-177
tuning capacitor,
fm/a-m 4 gang
3-837-660
contact plate “C’’,
battery negative
X-38376-82-2
rear cabinet ass’y
3-837-637
knob, band selector
3-837-668
pointer
3-837-623
knob, TUNING control
X-38376-83-0
right side cover ass’y
3-837-618
knob, AFC switch
Fig. 1-5
1-501-124-12
telescopic antenna
EXT, POWER (J05)
1-507-276-12
jack, 6 gang
DC OUT (J06)
record OUT {(J03)
MPX OUT (J01)
AUX IN (J02)
earphone (J04}
Fig. 1-6
1-§02-267
speaker
3-8.30-339-02
drum, volume indicator
1-507-276-12
jack, 6 gang
3-825-643
contact plate, battery positive
Fig. 1-7

SECTION 2
DISASSEMBLY
2-1. REAR CABINET REMOVAL
Left Side Cover Removal :
I. Remove the four screws labeled @) in Fig. 2-1.
2. Pull out the left side cover along with the
volume knob and tone knob as shown in
Fig. 2-1.
tapping screw
® P 3x10
knob, TONE
tapping screw
® P 3x10 7
Fig. 2-1
Right Side Cover Removal
3. Press down the antenna release button shown
in Fig. 2-2.
Pull out the telescopic antenna.
Remove the four screws labeled in Fig. 2-2.
Pull out the right side cover with the tuning
knob and battery lid as shown in Fig. 2-2.
nae
telescopic
antenna
button, antenna
release
tapping screw
@® P 3x10
knob, TUNING
battery lid
B) tapping screw
. ® P 3x10
Fig. 2-2
TFM-8100
Rear Cabinet Removal
ws
Remove
the
three
screws
labeled
©)
in
Fig.
2-3.
Lift
up
the
rear
cabinet.
screw, tapping screw, tapping
® P 3x45 4 ® P 3x45
Fig. 2-3
CHASSIS REMOVAL
Remove the rear cabinet.
Set the band selector to VHF WB (VHF
Weather Band) position as shown in Fig. 2-4,
Push the POWER switch button as shown in
Fig, 2-4.
Unsolder the pvc wire labeled (D) in Fig. 2-4.
Remove the screw labeled ® in Fig. 2-4,
Lift up the chassis.
€) tapping screw
®P 3x8
knob, band push
selector Jt button,
_ Power switch
Pve wire
(ORG)

TFM-8100W |
2-3. PRINTED CIRCUIT BOARD REMOVAL
1.
Remove
the
rear
cabinet
and
chassis.
2. Remove the four screws labeled @), the two
plates labeled G) and the slide switch shown
in Fig, 2-5.
screw
@ P2.6x6
_— zi
Fig. 2-5
3. Unsolder the following lead wires and the lug
terminal shown in Fig. 2-6.
a) three capacitor leads marked @
b) two tinned copper wires marked
c) lug terminal marked A
4. Loosen the green tie marked o
5. Detach the cement-contacted portions marked
* by using a sharp edge like a knife.
@ capacitor lead
e
capacitor
leads
ih eee areas ——
copper wires x A tug terminal
Fig. 2-6
6.
Ts
Push the back plate by a stick as shown in
Fig. 2-7.
Remove the back plate.
back plate,
dial scale
Fig. 2-7
Unsolder the four tinned copper wires shown
in Fig. 2-8.
Lift up the slide switch.
Remove the screw labeled (H) in Fig. 2-8.
tinned
copper wire
screw
(H) @ Pix6
slide
switch
Fig. 2-8

11.
12,
13,
14,
15,
16,
Remove the speaker.
Unsolder the four pve wires marked A in
Fig. 2-9,
Remove the screw labeled (1) and remove the
resonance indicator block.
Remove the screw labeled @) and remove the
power switch.
Pull out the tone control shown in Fig. 2-10.
Push down the printed circuit board squeezing
bar antenna holder.
2-4,
VHF WB BLOCK REMOVAL
Remove the screw labeled (K) in Fig, 2-11.
Unsolder the two lead wires shown in Fig. 2-11.
Unsolder the following lead wires shown in
Fig. 2-12.
a) black coaxial cable marked @
b) braided wire marked
c) ceramic capacitor lead marked a
d) tinned copper wire marked A
e) bar antenna lead marked ©
f) trimmer capacitor leg marked 6
4. Detach the cement-contacted portions marked
* by using a sharp edge like a knife.
5. Lift up the VHF WB block.
tapping screw
® P 2x6 )
Power switch
Apve wire
(BLU)
Apve wire
(RED)
:
pve wire
(RED)
coaxial
cable
(BLK)
resonance
screw
indicator
block
®
P3x6
tapping screw
X
® P 3x6 !
Apve
wire
VHF
WB
(BLK)
block
Apve
wire
(WHT)
Fig.
2-11
Fig. 2-9
holder, bar antenna
tinned copper
wire
coaxial
cable @
(BLK)
braided wire x
VHF WB
block
trimmer
capacitor leg o
Capacitor
lead
bar antenna
le ©
ad
tone
control
Fig. 2-12

2-5. DIAL CORD STRINGING
Preparation
1. Remove the chassis.
2. Cut the dial cord by the specified length as
shown in Fig, 2-13.
chick telat ES 6
dial cord, 0.25mm
one. adh ~{
31
3”
(795
a
ale
214, turns
3-837-674
shaft, dial
3-837-814
spring, dial cord
Stringing
1. Fix the dial cord to the protrusion (step @)
and string the cord in numerical order as shown
in Fig. 2-13.
Note: Pass through the dial cord. at
step (4) between the two cords of steps
(2) and (@) as shown in Fig. 2-14.
2. Fasten the both knots with a contact cement.
Pointer Setting
1. Rotate the dial shaft counterciockwise to the
full.
2. Set the pointer to the slit as shown in Fig. 2-15.
3-837-668
pointer,
slit
(pointer setting
position
Xs Vs beens
3-825-636 EX BYEIGE 1
pulley Ay E @) I
- @ Fix the cord with dial shaft and dial drum at
x se37 628 the eyelet. fully clockwise position.
sudo-chassis 3-837-619
drum, dial (at fully clockwise position)
: Fig. 2-15
Fig. 2-13
SECTION 3
CIRCUIT ADJUSTMENTS
3-1. IF ALIGNMENT
Test Equipments/Tools Required:
Rf signal generator (for fm and a-m)
Loop antenna
VTVM
Screwdriver for alignment
Oscilloscope
71. Fm I-f Alignment
Preparation:
Sweep/Marker Generator Connection:
to the telescopic antenna lead as
shown in Fig. 3-1.
Oscilloscope Connection: MPX OUT jack
Sweep Generator Frequency: 10.7 MHz
Marker Generator Frequency: 10.7 MHz
Band Selector Setting: FM
AFC Switch: OFF
Procedure:
1. Turn the core of discriminator transformer
(IFT F6) fully counterclockwise.
2. Turn the core of fm if transformers
(IFT Fl ~ IFT F5, IFT F7) to obtain the
maximum amplitude response curve as
shown in Fig. 3-3.
3. Turn the core of discriminator transformer
(IFT F6) to obtain the “S” curve response
as shown in Fig. 3-4.
to sweep/marker
generator
Fig. 3-1 | Sweep/marker generator coupling

sigtr-spere)!
oscilloscope
sweep/marker
generator
10.7 MHz
10.7 MHz
tel ant lead
Fig. 3-3 Fig. 3-4
Fig. 3-2. Fm i-f alignment setup
; Sweep/Marker Sweep/Marker ,
Adjustment Generator Generator Oscilloscope Adjust Remarks
Item : Connection
Coupling Frequency
F
a as Band selector: FM
IFT F3 AFC switch: OFF
Fig. 3-1 j i
FM I-f Ser ibibcs 10.7 MHz MEX-OUT jack} ier rq | MURS fer “maxanum
and Fig. 3-2 IFT FS amplitude and symmet-
IFT F6 ie S” curve on the
IFT F7 | S°OPS-
Band selector: VHF WB
ee IFT101 Adjust for maximum
amplitude on the os-
cilloscope.
2, Am I-f Alignment
Rf Signal Rf Signal Nr
Generator Generator VIM
Coupling Frequency
Connection
Remarks
Band selector: AM
Dial shaft: fully clockwise
455 kHz MPX OUT jack position
Adjust for maximum meter
reading.
Loop antenna
See Fig. 3-5
rf signal loop ant VTVM
generator test set
Fig. 3-5 ~A-m i-f alignment, frequency coverage and
tracking adjustment setup

FM-8100W
3-2. FREQUENCY COVERAGE AND TRACKING ADJUSTMENT
VTVM Connection: To MPX OUT jack
Modulation: FM....... 400 Hz +22.5 kHz frequency-modulated signal
Preparation:
Adjustment
Rf Signal
Generator
Coupling
AM....... 1kHz 30% amplitude-modulated signal
Rf Signal
Generator
Frequency
i
Receiver
Dial
Setting
Adjust
Remarks
FM
Frequency
Ceverage
FM
Tracking
85.5 MHz
Fully
downward
FM osc coil
L04
Telescopic
antenna lead
(See Fig. 3-6 |
and Fig. 3-7)
109.5 MHz
Fully
upward
FM osc
trimmer CT2
85.5 MHz
Tune to
85.5-MHz signal
FM rf coil
L03
109.5 MHz
Tune to
109.5-MHz signal
FM rf
trimmer CT1
Band selector: FM
AFC switch: OFF
Adjust for maximum
meter reading on VTVM.
AM
Frequency
Coverage
AM
Tracking
rf signal
generator
Loop
antenna
(See Fig. 3-5)
Telescopic
antenna lead
(See Fig. 3-6
and Fig. 3-7)
$20 kHz
Fully
downward
AM osc coil
LO7
test set
1,680 kHz
620 kHz
1,400 kHz
162.55 MHz
tel ant lead
Fully
upward
Tune to
620-kHz signal
Tune to
1,400-kHz signal
VTVM
Fig. 3-6 Fm frequency coverage and
tracking adjustment setup
AM osc
trimmer CT4
AM ant coil
L06
AM ant
trimmer CT3
VHF WB ant
coil L101
VHF WB rf
coil L102
VHF WB tripler
coil-1 L103
VHF WB tripler
coil-2 L104
VHF WB osc
coil L107
Band selector: AM
Adjust for maximum.
meter reading on VITVM-
Band selector: VHF WB
Adjust for maximum
meter reading on VT'VM.
to rf signal
generator
Fig. 3-7 Rf signal generator coupling