Sony WRR-801A Service Manual page 29

3. Frequency characteristic check
Procedure
Step 1: Tuner [1] (Tuner unit 1) checking
(1) Set the WRR-801A as follows;
Front panel (Tuner [1])
Channel setting: Group 00, 6901 channel
(800.125 MHz)
Muting: OFF
Rear panel
ATT (ANTENNA A, B) switch: 0 dB
(2) Connect the audio analyzer to the TUNER OUTPUT 1
connector via 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): 800.125 MHz
RF OUTPUT (Output level): 60 dBuV
MODULATION (Modulation frequency): 1 kHz
DEVIATION (Frequency deviation): ± 12 kHz
(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
procedure (3) is set also as follows.
n
10 kHz and 15 kHz modulation frequency must be set
by using the function generator.
MODULATION frequency
of signal generator
100 Hz
10 kHz
15 kHz
(7) Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture, and perform the
procedures (4), (5) and (6).
WRR-801A
WRU-801A
EMF
(= _53 dBm)
TUNER OUTPUT 1 connector
output level
0 ±2.0 dB
_20 ±2.0 dB
_28 ±2.5 dB
Step 2: Tuner [2] to Tuner [6] checking
When the TUNER UNIT WRU-801A is installed in the
Tuner [2] (Tuner unit 2) to Tuner [6] (Tuner unit 6) of the
WRR-801A, 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 WRR-
801A.
When performing the above described checking change the
following details as shown below, of the "Step 1. Tuner
[1] (Tuner unit 1) checking".
Tuner [1] → Tuner [2], [3], [4], [5], and [6]
TUNER OUTPUT 1 → TUNER OUTPUT 2, 3, 4, 5, and 6
4. Distortion ratio check
Procedure
Step 1: Tuner [1] (Tuner unit 1) checking
(1) Set the WRR-801A as follows;
Front panel (Tuner [1])
Channel setting: Group 00, 6901 channel
(800.125 MHz)
Muting: OFF
Rear panel
ATT (ANTENNA A, B) switch: 0 dB
(2) Connect the audio analyzer to the TUNER OUTPUT 1
connector via 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): 800.125 MHz
RF OUTPUT (Output level): 60 dBuV
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 0.8 %.
(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 3 %.
EMF
(= _53 dBm)
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