Sony TMR-RF940R User manual

TRANSMITTER
MICROFILM
AEP Model
SPECIFICATIONS
SERVICE MANUAL
TMR-RF940R
TMR-RF940R is transmitter
unit in MDR-RF940RK.

– 2 –
Notes on chip component replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
Flexible Circuit Board Repairing
•Keep the temperature of the soldering iron around 270 ˚C during
repairing.
•Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
•Be careful not to apply force on the conductor when soldering or
unsoldering
This section is extracted from
instruction manual. SECTION 1
GENERAL

– 3 – – 4 –
SECTION 2
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
CABINET (UPPER) ASS’Y
4 two claws
2 two claws
4 two claws
3 cabinet (upper) ass’
y
5 TX board
1 two screws
(P2.6
× 10)

– 9 – – 10 –
SECTION 4
EXPLEDED VIEW
• Items marked “*” are not stocked since they
are seldom required for routine service. Some
delayshouldbeanticipatedwhenorderingthese
items.
• The mechanical parts with no reference num-
ber in the exploded views are not supplied.
NOTE:
• -XX and -X mean standardized parts, so they
may have some difference from the original
one.
• Color Indication of Appearance Parts
Example:
KNOB, BALANCE (WHITE) . . . (RED)
↑↑
Parts Color Cabinet's Color
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
SECTION 5
ELECTRICAL PARTS LIST
Ref. No. Part No. Description Remark
NOTE:
• Due to standardization, replacements in the
parts list may be different from the parts speci-
fied in the diagrams or the components used
on the set.
• -XX and -X mean standardized parts, so they
may have some difference from the original
one.
• RESISTORS
All resistors are in ohms.
METAL: Metal-film resistor.
METAL OXIDE: Metal oxide-film resistor.
F: nonflammable
• Items marked “*” are not stocked since they
are seldom required for routine service.
Some delay should be anticipated when order-
ing these items.
• SEMICONDUCTORS
In each case, u: µ, for example:
uA. . : µA. . uPA. . : µPA. .
uPB. . : µPB. . uPC. . : µPC. .
uPD. . : µPD. .
• CAPACITORS
uF: µF
• COILS
Ref. No. Part No. Description Remark
TX
When indicating parts by reference
number, please include the board.
1 3-895-784-01 SPRING
2 4-957-332-01 CABINET (LOWER)
*3 A-4542-442-A TX BOARD, COMPLETE
4 X-4948-054-1 CABINET (UPPER) ASSY
5 1-559-892-11 CORD (WITH PLUG)
6 4-958-633-01 CUSHION (BATTERY CASE LID)
7 4-957-333-01 LID, BATTERY CASE
8 7-685-135-19 SCREW +P 2.6X10 TYPE2 NON-SLIT
9 4-987-337-01 LABEL (CHG), WARNING
10 4-989-335-01 TERMINAL, CHARGE
11 4-986-508-01 COVER (BATTERY CASE)
12 4-989-336-01 TERMINAL (COMMONNESS), CHARGE
13 3-846-312-01 SPACER
14 3-561-902-01 CLOTH, RETAINING, CASSETTE
15 3-880-474-01 CUSHION, 15X5X0.3
4
3
15
14
15
2
18
10
11
12
not supplied
7
9
6
5
13
not supplied
not supplied
*A-4542-442-A TX BOARD, COMPLETE
*******************
< CAPACITOR >
C01 1-163-141-00 CERAMIC CHIP 0.001uF 5% 50V
C02 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C03 1-128-007-11 ELECT CHIP 2.2uF 20% 35V
C11 1-163-141-00 CERAMIC CHIP 0.001uF 5% 50V
C12 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C13 1-128-007-11 ELECT CHIP 2.2uF 20% 35V
C21 1-107-823-11 CERAMIC CHIP 0.47uF 10% 16V
C22 1-164-489-11 CERAMIC CHIP 0.22uF 10% 16V
C23 1-163-131-00 CERAMIC CHIP 390PF 5% 50V
C24 1-163-131-00 CERAMIC CHIP 390PF 5% 50V
C31 1-163-135-00 CERAMIC CHIP 560PF 5% 50V
C32 1-163-141-00 CERAMIC CHIP 0.001uF 5% 50V
C41 1-128-393-11 ELECT CHIP 100uF 20% 10V
C42 1-164-222-11 CERAMIC CHIP 0.22uF 25V
C43 1-126-246-11 ELECT CHIP 220uF 20% 4V
C44 1-126-205-11 ELECT CHIP 47uF 20% 6.3V
C45 1-126-205-11 ELECT CHIP 47uF 20% 6.3V
C51 1-164-489-11 CERAMIC CHIP 0.22uF 10% 16V
C52 1-164-695-11 CERAMIC CHIP 0.0022uF 5% 50V
C53 1-163-141-00 CERAMIC CHIP 0.001uF 5% 50V
C54 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C55 1-163-116-00 CERAMIC CHIP 91PF 5% 50V
C56 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C57 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C58 1-163-116-00 CERAMIC CHIP 91PF 5% 50V
C59 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C60 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C61 1-163-241-11 CERAMIC CHIP 39PF 5% 50V
C62 1-163-243-11 CERAMIC CHIP 47PF 5% 50V
C63 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C64 1-163-112-00 CERAMIC CHIP 62PF 5% 50V
C65 1-163-108-00 CERAMIC CHIP 43PF 5% 50V
C66 1-163-059-91 CERAMIC CHIP 0.01uF 10% 50V
C67 1-163-089-00 CERAMIC CHIP 6PF 50V
C68 1-163-088-00 CERAMIC CHIP 5PF 50V
C69 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C70 1-163-094-00 CERAMIC CHIP 11PF 5% 50V
C71 1-163-096-00 CERAMIC CHIP 13PF 5% 50V
C72 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C73 1-163-092-00 CERAMIC CHIP 9PF 0.25PF 50V
C74 1-163-091-00 CERAMIC CHIP 8PF 50V
C75 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C76 1-163-091-00 CERAMIC CHIP 8PF 50V
C77 1-163-227-11 CERAMIC CHIP 10PF 0.5PF 50V
C78 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C79 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C80 1-163-094-00 CERAMIC CHIP 11PF 5% 50V
C81 1-163-227-11 CERAMIC CHIP 10PF 0.5PF 50V
C82 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C83 1-163-091-00 CERAMIC CHIP 8PF 50V
C84 1-163-090-00 CERAMIC CHIP 7PF 50V
C85 1-163-229-11 CERAMIC CHIP 12PF 5% 50V
C86 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C87 1-163-229-11 CERAMIC CHIP 12PF 5% 50V
C88 1-163-083-00 CERAMIC CHIP 1PF 50V
C89 1-163-087-00 CERAMIC CHIP 4PF 50V
C90 1-104-908-11 TANTALUM CHIP 47uF 20% 4V
C91 1-163-038-91 CERAMIC CHIP 0.1uF 25V
C92 1-163-113-00 CERAMIC CHIP 68PF 5% 50V
C93 1-163-038-91 CERAMIC CHIP 0.1uF 25V
C94 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C95 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C96 1-164-232-11 CERAMIC CHIP 0.01uF 50V
C97 1-135-158-21 TANTALUM CHIP 15uF 20% 4V
C98 1-163-141-00 CERAMIC CHIP 0.001uF 5% 50V
C100 1-107-725-11 CERAMIC CHIP 0.1uF 10% 16V
< DIODE >
D41 8-719-404-49 DIODE MA111
D42 8-719-975-06 LED CL-70G-CD (OFF/CHG)
D43 8-719-018-51 LED CL-170R-CD (POWER ON)
D44 8-719-045-99 DIODE RD2.2M-T1B
D51 8-719-939-02 DIODE SVC203CP
D52 8-719-421-40 DIODE MA77
D53 8-719-421-40 DIODE MA77
< FERRITE BEAD >
FB01 1-500-419-21 INDUCTOR, FERRITE BEAD
< IC >
IC01 8-759-998-71 IC BA3308F
IC21 8-759-701-39 IC NJM3404AM
IC22 8-759-177-69 IC TLV2362ID-ELL2500

– 11 –
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
< JACK >
J41 1-568-907-31 JACK,DC (POLARITY UNIFEID TYPE)
(DC IN 4.5V)
< CHIP CONDUCTOR >
JC01 1-216-296-00 CONDUCTOR, CHIP (3216)
JC02 1-216-296-00 CONDUCTOR, CHIP (3216)
JC03 1-216-296-00 CONDUCTOR, CHIP (3216)
JC04 1-216-296-00 CONDUCTOR, CHIP (3216)
JC05 1-216-296-00 CONDUCTOR, CHIP (3216)
JC06 1-216-296-00 CONDUCTOR, CHIP (3216)
JC07 1-216-295-00 CONDUCTOR, CHIP (2012)
JC08 1-216-295-00 CONDUCTOR, CHIP (2012)
< COIL >
L51 1-412-946-11 INDUCTOR ,CHIP 3.9uH
L52 1-412-948-11 INDUCTOR ,CHIP 5.6uH
L53 1-412-946-11 INDUCTOR ,CHIP 3.9uH
L66 1-416-385-11 COIL, AIR-CORE (TMR)
L67 1-416-385-11 COIL, AIR-CORE (TMR)
L68 1-416-385-21 COIL, AIR-CORE (TMR)
L69 1-416-385-21 COIL, AIR-CORE (TMR)
L70 1-412-925-11 INDUCTOR ,CHIP 68NH
L71 1-412-946-11 INDUCTOR ,CHIP 3.9uH
L72 1-412-946-11 INDUCTOR ,CHIP 3.9uH
< LINE FILTER >
LF01 1-403-601-21 FILTER, COMMON MODE
LF41 1-411-236-11 FILTER, EMI
LF42 1-411-236-11 FILTER, EMI
< TRANSISTOR/CHIP CONDUCTOR >
Q21 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q22 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q23 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q24 8-729-216-22 TRANSISTOR 2SA1162-G
Q25 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q31 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q43 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q44 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q45 8-729-200-63 TRANSISTOR 2SC2712L-TE85R
Q46 8-729-200-87 TRANSISTOR 2SC2714-Y
Q47 8-729-200-87 TRANSISTOR 2SC2714-Y
Q48 8-729-209-45 TRANSISTOR 2SC3120-TE85R
Q49 8-729-230-81 TRANSISTOR 2SC3606
Q50 8-729-230-81 TRANSISTOR 2SC3606
Q51 8-729-230-81 TRANSISTOR 2SC3606
Q52 8-729-216-22 TRANSISTOR 2SA1162-G
< RESISTOR/CHIP CONDUCTOR >
R01 1-216-085-00 METAL CHIP 33K 5% 1/10W
R02 1-216-049-00 METAL CHIP 1K 5% 1/10W
R03 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R04 1-216-097-00 METAL CHIP 100K 5% 1/10W
R05 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R06 1-216-033-00 METAL CHIP 220 5% 1/10W
R07 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R08 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R11 1-216-085-00 METAL CHIP 33K 5% 1/10W
R12 1-216-049-00 METAL CHIP 1K 5% 1/10W
R13 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R14 1-216-097-00 METAL CHIP 100K 5% 1/10W
R15 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R16 1-216-033-00 METAL CHIP 220 5% 1/10W
R17 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R18 1-216-073-00 METAL CHIP 10K 5% 1/10W
R21 1-216-073-00 METAL CHIP 10K 5% 1/10W
R22 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R23 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R24 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R25 1-216-093-00 METAL CHIP 68K 5% 1/10W
R26 1-216-085-00 METAL CHIP 33K 5% 1/10W
R27 1-216-081-00 METAL CHIP 22K 5% 1/10W
R28 1-216-081-00 METAL CHIP 22K 5% 1/10W
R29 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R30 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R31 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R32 1-216-061-00 METAL CHIP 3.3K 5% 1/10W
R33 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R42 1-216-023-00 METAL CHIP 82 5% 1/10W
R43 1-216-009-00 METAL CHIP 22 5% 1/10W
R44 1-216-053-00 METAL CHIP 1.5K 5% 1/10W
R45 1-216-033-00 METAL CHIP 220 5% 1/10W
R49 1-216-133-00 METAL CHIP 3.3M 5% 1/10W
R51 1-216-097-00 METAL CHIP 100K 5% 1/10W
R52 1-216-109-00 METAL CHIP 330K 5% 1/10W
R53 1-216-055-00 METAL CHIP 1.8K 5% 1/10W
R54 1-216-033-00 METAL CHIP 220 5% 1/10W
R55 1-216-097-00 METAL CHIP 100K 5% 1/10W
R56 1-216-033-00 METAL CHIP 220 5% 1/10W
R57 1-216-091-00 METAL CHIP 56K 5% 1/10W
R58 1-216-295-00 CONDUCTOR, CHIP (2012)
R59 1-216-001-00 METAL CHIP 10 5% 1/10W
R60 1-216-001-00 METAL CHIP 10 5% 1/10W
R61 1-216-001-00 METAL CHIP 10 5% 1/10W
R62 1-216-079-00 METAL CHIP 18K 5% 1/10W
R63 1-216-150-00 METAL CHIP 10 5% 1/8W
R64 1-216-001-00 METAL CHIP 10 5% 1/10W
R65 1-216-295-00 CONDUCTOR, CHIP (2012)
R66 1-216-001-00 METAL CHIP 10 5% 1/10W
R67 1-216-077-00 METAL CHIP 15K 5% 1/10W
R68 1-216-295-00 CONDUCTOR, CHIP (2012)
R69 1-216-001-00 METAL CHIP 10 5% 1/10W
R70 1-216-295-00 CONDUCTOR, CHIP (2012)
R71 1-216-001-00 METAL CHIP 10 5% 1/10W
TX

– 12 –
Ref. No. Part No. Description Remark
R72 1-216-073-00 METAL CHIP 10K 5% 1/10W
R73 1-216-073-00 METAL CHIP 10K 5% 1/10W
R74 1-216-295-00 CONDUCTOR, CHIP (2012)
R75 1-216-017-00 METAL CHIP 47 5% 1/10W
R76 1-216-001-00 METAL CHIP 10 5% 1/10W
R77 1-216-001-00 METAL CHIP 10 5% 1/10W
R78 1-216-077-00 METAL CHIP 15K 5% 1/10W
R79 1-216-003-11 METAL CHIP 12 5% 1/10W
R80 1-216-073-00 METAL CHIP 10K 5% 1/10W
R81 1-216-073-00 METAL CHIP 10K 5% 1/10W
R82 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R83 1-216-097-00 METAL CHIP 100K 5% 1/10W
R84 1-216-089-00 METAL CHIP 47K 5% 1/10W
R85 1-216-115-00 METAL CHIP 560K 5% 1/10W
R86 1-216-121-00 METAL CHIP 1M 5% 1/10W
R87 1-216-121-00 METAL CHIP 1M 5% 1/10W
R88 1-216-049-00 METAL CHIP 1K 5% 1/10W
R89 1-216-097-00 METAL CHIP 100K 5% 1/10W
R90 1-216-073-00 METAL CHIP 10K 5% 1/10W
R91 1-216-200-11 METAL CHIP 1.2K 5% 1/8W
R92 1-216-073-00 METAL CHIP 10K 5% 1/10W
R93 1-216-073-00 METAL CHIP 10K 5% 1/10W
< VARIABLE RESISTOR >
RV21 1-238-856-11 RES, ADJ, CERMET 10K
RV51 1-238-857-11 RES, ADJ, CERMET 22K
RV52 1-238-857-11 RES, ADJ, CERMET 22K
< SWITCH >
S41 1-571-674-11 SWITCH, SLIDE (POWER)
S51 1-571-478-11 SWITCH, SLIDE (CH1-CH2)
< VIBRATOR >
X51 1-767-455-11 VIBRATOR, CRYSTAL (16.090MHz)
X52 1-767-456-11 VIBRATOR, CRYSTAL (16.110MHz)
************************************************************
MISCELLANEOUS
***************
5 1-559-892-11 CORD (WITH PLUG)
TX
Sony Corporation
Personal A&V Products Company
TMR-RF940R
97H057546-1
Printed in Hungary © 1997. 8
Published by Quality Engineering Dept.
(Shibaura)
9-923-239-11

SERVICE MANUAL
TMR-RF940R
SUPPLEMENT-1
File this supplement with the service manual.
AEP Model
Subject:
1. Modification
2. Electrical Adjustments
Ver. 1.0 1998. 05

– 2 –
1. MODIFICATION
• Countermeasure for distortion and white noise.
Improvement of TMR-RF940R (TX board) Increase the capacity
of C21.
Add a 22 µF or 47 µF electrolytic capacitor in parallel with C21.
SCHEMATIC DIAGRAM
• Original Service Manual page 7.
(Location E – G, 6 – 8)
!: Added portion
[TX Board]
PRINTED WIRING BOARD
• Original Service Manual page 5 and 6.
(Location A – B, 4 – 6)
!: Added portion
[TX Board] – Conductor Side –
You can use any of the following capacitors.
Part No.
22 µF/4 V 1-124-430-∏1-126-263-∏
22 µF/6.3 V 1-115-863-∏1-123-618-∏1-124-222-∏1-126-153-∏
1-126-419-∏1-126-555-∏1-126-269-∏
22 µF/10 V 1-124-638-∏1-123-644-∏1-124-228-∏1-126-273-∏
1-126-427-∏1-126-783-∏1-128-054-∏
47 µF/4 V 1-107-294-∏1-126-265-∏1-126-553-∏1-126-779-∏
47 µF/6.3 V 1-123-293-∏1-123-647-∏1-124-224-∏1-126-154-∏
1-126-271-∏1-126-421-∏1-126-513-∏1-126-557-∏
47 µF/10 V 1-104-657-∏1-111-239-∏1-123-294-∏1-124-892-∏
1-126-640-∏1-126-744-∏1-126-785-∏
(Any capacitor can be used if its capacity is more than 22 µF and also
small enough for the case of this set.)
$
@

– 3 –
2. ELECTRICAL ADJUSTMENTS
Note:
• Perform countermeasure for distortion before adjustments.
Adjust and confirm the unit by following procedure shown below after this countermeasure.
• Please adjust the transmitter and the headphone together.
Procedure for Measurements and Adjustments
Lastly, we would like to explain the procedure for adjusting this model. As this model adopts a Stereo Modulation method called “FM-
FM”, it is difficult to perform the adjustments with common measurement equipments.
The following adjustment should be performed with a spectrum analyzer.
Measurement of White noise level
1) Set the models and necessary equipments as shown in the figure1.
2) Observe the waveform of the oscilloscope. In case that a beat can be seen in the waveform, select a channel (CH1 or CH2) with less
beat.
3) Use the CCIR/ARM Filter for the noise meter and measure the white noise level. If the value is below –63 dBV (0.7 mVrms), the level
is acceptable.
Figure 1.
Adjustment ofTransmitter
Set the transmitter and a spectrum analyzer as shown below.
Figure 2.
1 m
AC adaptor
AC-E455D (supplied)
AC 230V 50 Hz
noise filter
(supplied)
SP1 Lch
or
SP2 Rch
oscilloscope
noise meter
Use CCIR/ARM filter.
Connect nothing to the plug
of noise filter.
Use supplied
Ni-cd battery. VOL MAX.
AC 230V 50 Hz
AC-E455D (supplied) Connect nothing.
ANT
spectrum analyzer
Observe the waveform on the spectrum analyzer
without Audio input signal into transmitter.

– 4 –
Confirm the main carrier frequency (CH1, CH2) (See “a” in the figure 3)
The correct value is as follows.
CH1: 433.6 MHz ± 200 kHz
CH2: 434.2 MHz ± 200 kHz
Confirm the sub carrier frequency (See “b” in the figure 3)
The correct value is 42 kHz ± 2 kHz
Adjust the modulation of sub carrier to be 15 dB ± 0.5 dB as follows (See “c” in the figure 3)
CH1 Deviation adjustment: Turning RV51.
CH2 Deviation adjustment: Turning RV52.
Figure 3.
L-R Deviation adjustment
Figure 4.
1) Set the equipments as the same as the figure 2.
2) Input a signal of 1 kHz 316 mVrms to Lch of the transmitter.
Confirm Main carrier
frequency.
ab
C
Confirm Sub carrier frequency.
Confirm Sub carrier
modulation degrees.
SPAN 200 kHz
10 dB/DIV
RBW 1 kHz
VBW 1 kHz
SWP
2.0 sec.
* Adjust CENTER Frequency to the main carrier frequency.
Sub spectrum “A”
SPAN 200 kHz
10 dB/DIV
RBW 1 kHz
VBW 1 kHz
SWP
2.0 sec.
* Adjust CENTER Frequency to the main carrier frequency.

– 5 –
3) Observe the waveform on the spectrum analyzer and turn RV21 to adjust the modulation degree of a sub spectrum “A” in the figure 4
to be narrowest as shown below.
4) At this time, measure AC voltage of IC21 Pin 1on the TX board with AC voltmeter and define the value as “V0” for the next
adjustment.
5) Turn the RV21 again so that the AC voltage of IC21 Pin 1becomes the same value as the two thirds of “V0”. (V1=V0×2/3)
Adjustment Location: TX board (See page 6.)
Adjustment and confirmation without a spectrum analyzer
Please confirm the units by following procedure shown below.
Here a series of procedure which can be performed without a spectrum analyzer is introduced.
Deviation adjustment/confirmation
1) Input a 400 Hz 316 mV signal into the left channel of transmitter.
2) Measure the AC voltage at the Pin 1of IC21 (MJM2100M) with AC voltmeter.
Spec.: 100 ± 10 mVrms
If not, turn RV21 for obtaining the value.
Adjustment Location: TX board (See page 6.)
Sub-carrier frequency and output level confirmation
1) No signal is input into transmitter.
2) Connect a oscilloscope and a frequency counter to the test point TP1.
3) Confirm the voltage is within the following spec.
Spec.: 0.55 Vp-p
4) Confirm the frequency is within the following spec.
fsub=42 ± 2 kHz
0.55 Vp-p
SCHEMATIC DIAGRAM
• Original Service Manual page 7.
(Location C – E, 6 – 8)
!: Connection point
[TX Board]
PRINTED WIRING BOARD
• Original Service Manual page 5.
(Location A – C, 4 – 6)
+
–
oscilloscope
IN
frequency counte
r
OUT
coaxial cable
[TX Board] – Conductor Side –
^

– 6 –
Carrier frequency modulation adjustment/confirmation
This has to be done for a pair of set.
Before starting, match the channel of both units.
1) Input a 400 Hz 316 mV signal into the left channel of transmitter.
2) Measure the AC voltage at the test point TP2 of MDR-RF940R RX board with AC voltmeter.
Spec.: 13 ± 1.5 mVrms
If not, turn RV51 of TMR-RF940R (channel 1) or RV52 (channel 2) for obtaining the value.
SCHEMATIC DIAGRAM
• MDR-RF940R Service Manual page 8.
(Location B – D, 9 – 11)
!: Connection point
[RX Board]
PRINTED WIRING BOARD
• MDR-RF940R Service Manual page 5.
(Location F – H, 4 – 6)
[RX Board] – Side A –
Adjustment Location:
[TX Board] – Conductor Side –
^
AC voltmete
r
+
–
RV51 (CH1)
RV52 (CH2)
RV21
Deviation Adjustment
Carrier
Frequency
Modulation
Adjustment
IC01
IC21
1
Sony Corporation
Personal A&V Products Company
9-923-239-81
98E0539-1
Printed in Japan © 1998. 5
Published by Quarity Engineering Dept.
(Shibaura)
TMR-RF940R