Sony WRU-806B Service Manual page 17

3. Frequency Characteristic Check
Procedure
n
The checking procedures describe that the WRU-806B (to
be adjusted) is installed into the Tuner [1] slot on the MB-
X6.
(1) Set the MB-X6 as follows :
WRU-806B Front panel (Tuner [1])
Channel setting :
CE38 model ; Group 00, 3932 channel (618.000 MHz)
U30 model ; Group 00, 3201 channel (578.125 MHz)
U42 model ; Group 00, 4401 channel (650.125 MHz)
Muting: OFF
Rear panel
ATT (ANTENNA A, B) switch : 0 dB
(2) Connect the audio analyzer to the TUNER OUTPUT 1
connector via microphone amplifier.
(3) Connect the signal generator to the ANTENNA A IN
connector with DC cut fixture.
(4) Set the signal generator as follows :
Signal generator setting
FREQUENCY (carrier frequency) :
CE38 model ; 618.000 MHz
U30 model ; 578.125 MHz
U42 model ; 650.125 MHz
RF OUTPUT (Output level) : 60 dBuV
MODULATION (Modulation frequency) : 1 kHz
DEVIATION (Frequency deviation)
(5) Read the output level of the TUNER OUTPUT 1
(indication of the audio analyzer).
This level is specified to be 0 dB.
(6) Change the MODULATION (modulation frequency) of
the signal generator as follows, and check the output
level with respect to the output level under the proce-
dure (3) is set also as follows.
n
40 Hz and 18 kHz modulation frequency must be set by
using the function generator.
MODULATION frequency
of signal generator
40 Hz
18 kHz
(7) Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture, and perform the proce-
dures (4), (5) and (6).
WRU-806B
(= _53 dBm)
EMF
: ± 12 kHz
TUNER OUTPUT 1 connector
output level
_1.5 ± 1.0 dB
_35.0 ± 3.0 dB
4. Distortion Ratio Check
Procedure
n
The checking procedures describe that the WRU-806B (to
be adjusted) is installed into the Tuner [1] slot on the MB-
X6.
(1) Set the MB-X6 as follows :
WRU-806B Front panel (Tuner [1])
Channel setting:
CE38 model ; Group 00, 3932 channel (618.000 MHz)
U30 model ; Group 00, 3201 channel(578.125 MHz)
U42 model ; Group 00, 4401 channel(650.125 MHz)
Muting : OFF
Rear panel
ATT (ANTENNA A, B) switch : 0 dB
(2) Connect the audio analyzer to the TUNER OUTPUT 1
connector via microphone amplifier.
(3) Connect the signal generator to the ANTENNA A IN
connector with DC cut fixture.
(4) Set the signal generator as follows :
Signal generator setting
FREQUENCY (carrier frequency) :
CE38 model ; 618.000 MHz
U30 model ; 578.125 MHz
U42 model ; 650.125 MHz
RF OUTPUT (Output level) : 60 dBuV
MODULATION (Modulation frequency) : 1 kHz
DEVIATION (Frequency deviation)
(5) Set the audio analyzer to the distortion mode, and check
that the distortion ratio is less than 1.0 %.
(6) Change the MODULATION (modulation frequency) of
the signal generator as shown below.
MODULATION (modulation frequency) : 10 kHz
(Note ; 10 kHz modulation frequency must be set by
using the function generator.)
Check that the distortion ratio is less than 5.0 %.
(7) Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture, and perform the proce-
dures (4) through (6) above.
(= _53 dBm)
EMF
: ± 40 kHz
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