Sony MB-806A Service Manual page 37

4. Distortion ratio check
Procedure
Step 1: Tuner |1| (Tuner unit 1) checking
The checking procedures describe that the WRU-806A (to
be adjusted) is installed into the Tuner slot on the MB-
806A.
(1) Set the MB-806A as follows;
Front panel (Tuner [1])
Channel setting:
CE62 model; Group 00, 6301 channel (806.125 MHz)
CE69 model; Group 00, 6933 channel (858.125 MHz)
AU66 model; Group00, 6701 channel (799.250 MHz)
Muting: OFF
Rear panel
ATT (ANTENNA A, B) switch: 0 dB
(2) Connect the audio analyzer to the TUNER OUTPUT 1
connector via MIC amp.
(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):
CE62 model; 806.125 MHz
CE69 model; 858.125 MHz
AU66 model; 799.250 MHz
RF OUTPUT (Output level): 60 dBUVEMF
(= -53 dBm)
MODULATION (Modulation frequency): 1 kHz
DEVIATION (Frequency deviation): +40 kHz
(5) Set the audio analyzer to the distortion mode, and
"check that the distortion ratio is less than 0.7 %.
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 4 %.
Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture, and perform the
procedures (4) through (6) above.
(6
Vm
(7
—
3-12
(8) Set the channel setting (Tuner [4]) and FREQUENCY
(carrier frequency) of the signal generator as shown ()
and (2) below.
Perform the procedures (1) to (7) above, for each
channel setting (®) and @).
@) Channel setting:
CE62 model: Group 00, 6217 channel (800.125 MHz)
CE69 model: Group 00, 6901 channel (854.125 MHz)
AU66 model: Group 00, 6601 channel (792.250 MHz)
Signal generator setting:
FREQUENCY (Carrier frequency)
CE62 model: 800.125 MHz
CE69 model: 854.125 MHz
AU66 model: 792.250 MHz
® Channel setting:
CE62 model: Group 00, 6363 channel (813.875 MHz)
CE69 model: Group 00, 6964 channel (862.000 MHz)
AU66 model: Group 00, 6751 channel (805.500 MHz)
Signal generator setting:
FREQUENCY (Carrier frequency):
CE62 model: 813.875 MHz
CE69 model: 862.000 MHz
AU66 model: 805.500 MHz
Step 2: Tuner [2] to Tuner [6] checking
When the WRU-806A Tuner Unit is installed in the Tuner
(Tuner unit 2) to Tuner [6] (Tuner unit 6) of the MB-
806A, perform the adjustments from procedures (1) to (7)
of "Step 1. Tuner | 1] (Tuner unit 1) checking" on the
respective tuner units that are installed in the MB-806A.
When performing the above described checking change the
following details as shown below, of the "Step 1. Tuner
(Tuner unit 1) checking".
Tuner — Tuner [2], [3], [4], [5], and [6]
TUNER OUTPUT | — TUNER OUTPUT 2, 3, 4, 5, and 6
5. RF level indicator/RF indicator check
Procedure
Step 1: Tuner [4] (Tuner unit 1) checking
The checking procedures describe that the WRU-806A (to
be adjusted) is installed into the Tuner [1] slot on the MB-
806A.
MB-806A (CE)
WRU-806A (CE, AU)