Sony WRR-801A Service Manual page 21

3-2-1. Tuner unit (WRU-801A) Adjustment
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 WRR-801A RSSI learning.
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 A IN
1 2
Tuner
Procedure
Step 1: Preparation
Set the signal generator as follows:
Signal generator setting
FREQUENCY (Carrier frequency): 796.000 MHz
RF OUTPUT (Output level): 35 dBuV
MODULATION (Modulation frequency):
Step 2: Tuner [1] (Tune unit 1) adjustment
(1) Connect the signal generator to the ANTENNA A IN
connector with DC cut fixture.
(2) Turn OFF the WRR-801A POWER switch.
(3) Set the RF OUTPUT (output level) of the signal
generator to the OFF.
(4) While pressing the "SET" button on the front panel
(Tuner [1]), turn on the WRR-801A POWER switch.
WRR-801A
WRU-801A
DC cut fixture
ANTENNA B IN
WRR-801A
3 4 5 6
WRU-801A
EMF
(= _78 dBm)
OFF (No modulation)
(5) Indication on LCD (Tuner [1]) appears as follows:
LCD:
-SOL-
A C1 L
(6) Set the RF OUTPUT (output level) of the signal
generator to the ON.
(7) Check first that indication "L" of "AC1L" on the LCD
(Tuner [1]) has disappeared, and then press the "SET"
button on the front panel (Tuner [1]).
n
If the "L" indication does not disappear from the LCD
(on A area: refer to the previous procedure (5) (when
the RF input level is lower than the reference level) or
"H" is displayed (when the RF input level is higher
than the reference level), perform the following
adjustment.
1 Check the RF output level and frequency of the
signal generator (perform re-setting if necessary),
and repeat from procedure (1).
2 If the above conditions (the "L" indication does
not disappear, or "H" is displayed) remain even
after re-adjustment, it is necessary to replace the
new tuner unit (WRU-801A).
(8) Indication on LCD (Tuner [1]) appears as follows:
LCD:
B C1 L
(9) Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture.
(10)Check first that indication "L" of "BC1L" on the LCD
has disappeared, and then press the "SET" button on
the front panel (Tuner [1]).
(11)Indication on the LCD (Tuner [1]) appears as follows:
LCD:
A C2 L
(-SQL- )
A
(A C1 L)
(B C1 L)
(A C2 L)
3-3