Yamaha TX-497, Service Manual

Page: 11 / 32

11
TX-497
TX-497
Adjustment item
Verification of
sensitivity.
Verification of the signal
meter.
Verification of auto
tuning.
Step
1
2
3
Signal (ANT IN)
AM SG:
171 kHz/225 kHz/270
kHz 90 dB
µ
,
1 kHz,
30% modulation
AM SG:
225 kHz 90 dB
µ
,
ANT input 90 dB
µ
ANT input -10 dB
µ
or
less
AM SG:
225 kHz 60 dB
µ
,
1 kHz,
30% modulation
Adjusted
point
Tuning
button
Reception
frequency
Preset
C-2: 171 kHz
C-3: 225 kHz
C-4: 270 kHz
Preset
B-2: 225 kHz
Preset
B-2: 225 kHz
Rating
To be less than 66
dB
µ
.
Make sure that the
signal meter is
turned on.
Make sure that the
signal meter is
turned off.
Automatic reception
should be available
when the tuning UP
or DOWN key is
pressed.
Audio muting should
be applied during
tuning.
Test point
OUTPUT
<LW TUNER SECTION>
To be adjusted after MW section adjustment.
Use the specified dummy anetenna for loop antenna.
AM
SG
AM ANT
GND
AM dummy antenna
AM loop antenna