Tuner Adjustments - Yamaha CRX-E100 Service Manual

TUNER ADJUSTMENTS

Measuring Instruments
FM signal generator (FM SG)
Stereo signal generator (SSG)
AM signal generator (AM SG)
Distortion meter (DIST. M)
AC voltmeter (ACVM)
DC voltmeter (DCVM)
Oscilloscope
Low pass filter (YLF-15, fc=15kHz)
Oscillator
FM Adjustment
Before Adjustment
1) For dB, 1µV=0dBµ
Example : 60dBµ=1mV
2) 100% modulation means that the frequency deviation is
± 75kHz.
Connection diagram (Measuring instruments)
1) Discriminator balance adjustment
FM
FM ANT
FM
dummy
SG GND
antenna
Oscillator
2) Monaural distortion verification
FM
ANT
FM
FM
TUNER
dummy
SG
P. C. B.
GND
antenna
Oscillator
TUNER
DCVM
P. C. B.
L
Oscilloscope
R
REC
OUT
DIST. M
Dummy antenna
FM dummy antenna
10Ω 45Ω
E1 E2
FM SG
(50Ω)
E2 (dB) = E1 (dB) —6 (dB)
FM dummy antenna
E1
E2
FM SG
(75Ω)
E2 (dB) = E1 (dB)
AM dummy antenna
10KΩ
AM SG
(50Ω)
3) Install the Matching Transformer and connect FM SG.
4) Set each switch to the following position unless other-
wise specified.
INPUT SELECTOR .................. TUNER
TUNING MODE ....................... AUTO
3) Stereo distortion verification/separation verification
FM
ANT
FM
TUNER
FM
dummy
SG P. C. B.
GND
antenna
SSG
4) Sensitivity verification
FM
ANT
FM
FM TUNER
dummy
SG P. C. B.
GND
antenna
RX-E100
RECEIVER
(75Ω)
RECEIVER
(75Ω)
AM ANT
GND
L
Oscilloscope
R
YLF-15
REC
(LPF)
ACVM
OUT
DIST. M
L
Oscilloscope
R
REC
ACVM
OUT
DIST. M
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