Wru-806A Tuner Unit Adjustment - Sony MB-806A Service Manual

3-2-1. WRU-806A Tuner Unit Adjustment
The adjustment must be performed with WRU-806A Tuner
Unit installed with MB-806A unit.
1. Muting level and RF level adjustment
Perform this adjustment when Muting levels deviate from
the specification.
This adjustment is performed automatically by the learning
function of the WRU-806A (MB-806A) RSSI learning.
Preparation
Before the adjustments, turn off the POWER switch of the
MB-806A, and perform the following.
1. Remove the case cover of the MB-806A.
2. Remove the tuner unit (WRU-806A) to be adjusted
from the MB-806A. Refer to " Section 1. Operating
Instructions " for removal.
3. Remove the upper side case lid of the tuner unit
(WRU-806A), and insert the tuner unit (WRU-806A)
to the slot of the MB-806A.
Equipment and Tools
Signal generator
DC cut fixture (See "How to make DC cut fixture" on
page 3-1.)
Connection
Signal
generator
DC cut fixture
| ANTENNA BIN
DC cut fixture
ANTENNA AIN
RF-92 board
MB-806A
Tuner {1] [2] [3} [4] (5) [6]
eS
WRU-806A
$708 —
Tuner unit
(WRU-806A)
MB-806A (CE)
WRU-806A (CE, AU)
Procedure
Step 1: Preparation
Set the signal generator as follows:
Signal generator setting
FREQUENCY (carrier frequency):
CE62 model; 802.000 MHz
CE69 model; 855.000 MHz
AU66 model; 795.000 MHz
RF OUTPUT (Output level): 35 dBUVEMF
(= -—78 dBm)
MODULATION (Modulation frequency):
OFF (No modulation)
Step 2: Tuner [1| (Tune unit 1) adjustment
The adjustment procedures describe that the WRU-806A
(to be adjusted) is installed into the Tuner [1]slot on the
MB-806A.
(1) Connect the signal generator to the ANTENNA A IN
connector with DC cut fixture.
(2) Turn OFF the MB-806A POWER switch.
(3) Set the RF OUTPUT (output level) of the signal
generator to the OFF.
(4) While pressing the S708 switch on the RF-92 board
(WRU-806A, Tuner [1]}), turn on the MB-806A
POWER switch.
(5) Indication on LCD (Tuner [1] appears as follows:
LCD:
(-SQL- )
- SUL ~
'
A ~ ff 3 ®@
| a ie
(AC1L)
(6) Set the RF OUTPUT (output level) of the signal
generator to the ON.
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