Sony WRU-806B User manual

UHF SYNTHESIZED TUNER UNIT
WRU-806B
SERVICE MANUAL
2nd Edition
Serial No. 104001 and Higher: WRU-806B (U30)
Serial No. 104001 and Higher: WRU-806B (U42)
Serial No. 421001 and Higher: WRU-806B (CE38)

WRU-806B
!WARNING
This manual is intended for qualified service personnel only.
To reduce the risk of electric shock, fire or injury, do not perform any servicing other than that
contained in the operating instructions unless you are qualified to do so. Refer all servicing to
qualified service personnel.
!WARNUNG
Die Anleitung ist nur für qualifiziertes Fachpersonal bestimmt.
Alle Wartungsarbeiten dürfen nur von qualifiziertem Fachpersonal ausgeführt werden. Um die
Gefahr eines elektrischen Schlages, Feuergefahr und Verletzungen zu vermeiden, sind bei
Wartungsarbeiten strikt die Angaben in der Anleitung zu befolgen. Andere als die angegeben
Wartungsarbeiten dürfen nur von Personen ausgeführt werden, die eine spezielle Befähigung
dazu besitzen.
!AVERTISSEMENT
Ce manual est destiné uniquement aux personnes compétentes en charge de l’entretien. Afin
de réduire les risques de décharge électrique, d’incendie ou de blessure n’effectuer que les
réparations indiquées dans le mode d’emploi à moins d’être qualifié pour en effectuer d’autres.
Pour toute réparation faire appel à une personne compétente uniquement.

1
WRU-806B
Table of Contents
Manual Structure
Purpose of this manual ................................................................. 3
Related manuals ........................................................................... 3
1. Service Overview
1-1. Boards Location .............................................................. 1-1
1-2. WRU-806B Removal ...................................................... 1-1
1-3. WRU-806B Checking ..................................................... 1-1
1-4. Error Messages ............................................................... 1-2
1-5. Setting / Release of Muting Function ............................. 1-2
1-6. Lead-free Solder ............................................................. 1-2
2. Electrical Alignment
2-1. Preparation ...................................................................... 2-1
2-1-1. Equipment and Tools ............................................2-1
2-2. Adjustments .................................................................... 2-2
2-2-1. Muting Level and RF Level Adjustment ............... 2-3
2-2-2. Output Level Adjustment ......................................2-5
2-2-3. Overall Characteristics Check ............................... 2-7
3. Spare Parts
3-1. Notes on Repair Parts ..................................................... 3-1
3-2. Exploded Views .............................................................. 3-2
3-3. Electrical Parts List ......................................................... 3-3
3-4. Supplied Accessories .................................................... 3-21
4. Block Diagrams
4-1. Circuit Description .......................................................... 4-1
4-2. CPU Pin Description .......................................................4-2
4-2-1. Pin Description of CPU (IC601 on RF-155
Board) .................................................................... 4-2
4-3. Overall Block Diagrams .................................................4-5
Overall ............................................................................ 4-5
5. Board Layouts
DP-476 ............................................................................ 5-1
RF-155 ............................................................................ 5-1
6. Schematic Diagrams
DP-476 ............................................................................ 6-1
RF-155 ............................................................................ 6-2

3
WRU-806B
Purpose of this manual
This manual describes the information items that premise the service based on the
components parts assuming use of system and service engineers.
Related manuals
The following manuals are available in this model.
If this manual is required, please contact your local Sony Sales Office/Service
Center.
..
..
.Instruction Manual (Supplied with units)
This manual is necessary for application and operation of units.
Manual Structure

1-1
WRU-806B
Section 1
Service Overview
1-1. Boards Location
1-2. WRU-806B Removal
For removing a WRU-806B from the MB-X6, refer to “In-
stalling the tuner units” in the Operating Instructions.
1-3. WRU-806B Checking
The following procedures describe how to prove WRU-
806B (repair unit) whether it needs to be repaired or not.
Equipment Required : MB-X6 (quality unit)
WRU-806B (quality unit)
(1) Install the repair WRU-806B to be examined in a quali-
ty MB-X6.
(2) Check the fault with a quality MB-X6.
.If there is a fault, WRU-806B (repair unit) is defective.
Check the WRU-806B then fix a faulty section, and
perform “2. Electrical Alignment”.
.If there is no fault found on the MB-X6, repairing
WRU-806B is no longer defective. Thus the repairing
MB-X6, other than WRU-806B, is defective.
DP-476 board
RF-155 board

1-2 WRU-806B
1-4. Error Messages
The following error messages will appear if an error is detected by the built-in self diagnostics function of the WRU-806B
installed in the MB-X6.
Error Massage Comments Countermeasure
Err 01 An error occurs in EEPROM data. Take both of the following remedial measures.
. Write the frequency data that corresponds to the desired destination
location, into EEPROM.
. Perform the RF squelch adjustment and the RF level indicator adjustment.
(Refer to Section 2. Electrical Alignment).
Err 02 PLL synthesizer circuit failed Malfunction of WRU-806B.
Check the WRU-806B then fix a faulty section, and perform “2. Electrical Alignment”.
NO TONE The tone signal is present, or audio Make sure that the transmitter is turned on. If it is, then the problem lies in
signal output is muted because the the transmitter’s tone signal generator or the tuner’s tone squelch circuit.
receiver received a tone signal other .To check the characteristics, perform “2-2-3. Overall Characteristic Confirmation”.
than 32.768 kHz signal. If there are out of characteristics, tuner unit may defect.
. Check the WRU-806B then fix a faulty section, and perform “2. Electrical
Alignment”.
n
If you are using a WRT-810A wireless microphone, a “NO TONE”message
appears when you turn off the AF switch, but this is normal.
1-5. Setting / Release of Muting Function
Set or release the following functions by operating the button on the front panel of the WRU-806B installed in the MB-X6.
n
The muting function can be set and released separately for tuner [1] to [6] . (Tuner [1] to [6] ; when WRU-806B installed
in the MB-X6.)
Function Setting / Release
.Muting OFF by RF signal input level Releasing the muting function: When pressing the “GP”and “CH”buttons, turn ON the
.Muting OFF by tone squelch POWER switch.
.Muting OFF by noise squelch Setting the muting function (Normal operation mode):Turn OFF the POWER switch.
Default Factory Setting : Setting the muting function
1-6. Lead-free Solder
Boards requiring use of unleaded solder are printed with a lead free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size.)
: LEAD FREE MARK
m
.Be sure to use the unleaded solder for the printed circuit board printed with the lead free mark.
.The unleaded solder melts at a temperature about 40 dC higher than the ordinary solder, therefore, it is recommended to
use the soldering iron having a temperature regulator.
.The ordinary soldering iron can be used but the iron tip has to be applied to the solder joint for a slightly longer time. The
printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful.

2-1
WRU-806B
Section 2
Electrical Alignment
2-1. Preparation
2-1-1. Equipment and Tools
Equipment
Name Specifications Model name
Signal generator Frequency : 100 kHz to 990 MHz HEWLETT PACKARD 8656B or equivalent
Spectrum analyzer Frequency : 10 kHz to 5 GHz ADVANTEST TR4173 or equivalent
DC voltmeter (Multi meter) Effective digits : 4 digits _
Audio analyzer Frequency : 10 Hz to 100 kHz HEWLETT PACKARD 8903B equivalent
RF millivoltmeter Frequency : 10 kHz to 1 GHz MEGURO MV-19B, C (with 50 Ztermination prove chip
MP-3109) or equivalent
Level meter Frequency : 20 Hz to 100 kHz _
Noise meter Frequency : 10 Hz to 500 kHz MEGURO MN-445B or equivalent
Filter (included) : A weighted filter
Tracking generator Frequency : 100 kHz to 2 GHz ADVANTEST TR4153A or equivalent
Function generator 32.768 kHz (and 32.782 kHz) ±1 Hz HEWLETT PACKARD 8904A or equivalent
signal (sine wave) can be generated.
Microphone amplifier Gain : 0 dB to 70 dB _
(with A weighted filter)
Oscilloscope Frequency : DC to 30 MHz _
Tools
Name Part No. Remarks
Adjuster (0.4 x 1.3 mm) 7-721-052-81 For adjustment
DC cut fixture _Refer to “How to make DC cut fixture”
91 Zmetal film resistor 1-214-609-00
MB-X6 _Tuner Base Unit
How to make DC cut fixture
Required parts
BNC-J connector; 1 (Part No. 1-562-261-21)
BNC-P connector; 1 (Part No. 1-560-257-11)
Ceramic capacitor 0.001 uF ; 1 (Part No. 1-161-456-00)
BNC-J connector
(1-562-261-21)
Ceramic capacitor
0.001uF 50 V (1-161-456-00)
Cut Plated wire (0.6 to 0.8 ø)
2 mm
3mm
BNC-P connector
(1-560-257-11)
Solder

2-2 WRU-806B
2-2. Adjustments
This section describes the following adjustments (and
checks) required to satisfy the specifications.
Adjustment Item
2-2-1. Muting Level and RF Level Adjustment
2-2-2. Output Level Adjustment
2-2-3. Overall Characteristic Check
1. Output Level Check
2. S/N Check
3. Frequency Characteristic Check
4. Distortion Ratio Check
5. RF Level Indicator Check
6. AF Level Indicator/AF Indicator Check
7. Muting Level/RF Indicator Check
8. BATT Indicator Check
9. Tone Squelch Check
10. DC +9 V OUT Voltage Check
n
0 dBuVEMF = _113 dBm
(EMF = Electromotive force)
0 dBm = 1 mW at 50 Z loaded
Note on Adjustment
The RF level of the input signal (the output level of the sig-
nal generator) for adjustment is expressed as an open ended
voltage in unit dBuVEMF (0 dBu = 1 uVEMF).
The adjustment is to be performed by calibrating the output
level of the signal generator as shown below.
Calibration method
(1) Connect the RF millivoltmeter to the signal generator as
shown in the figure below.
(2) Adjust the level of the output signal from the signal gen-
erator (SSG) so that the RF millivoltmeter reads 50 mV.
The level of the output signal from the signal generator
(SSG) when RF millivoltmeter reads 50 mV shall be
specified as 100 dBuVEMF (at no load).
V
Signal generator
(SSG)
RF millivoltmeter
(set in 100 mV range)
50 Z
termination probe
Adjust the output of
the signal generator
(SSG) so that the
meter reads 50 mV.
50 mV50 Z
50 Z
OSC
100 dBu