Onkyo TX-7920 - Adjustment Procedures - FM Section; FM IF and VCO Adjustments; FM Stereo Distortion and Separation; FM Tuned Indicator Level Adjustment

FM section
Item Step | Connection of FM SG output Stereo modu- Tuned Output indicator Adjustment Adjust for Remarks
instrument lator output frequency point
DC voltmeter L101 0+20mV Set the FM mode
99.1MHz switch to MONO. Repeat
Fig. 1 1kHz,75kHz devi. 99.1MHz the steps 1 and 2 util
65dBf(60dB) Distortion L102 no further adjustment
analyzer in necessary.
a SS ew : 2 =
1kHz,75kHz devi. 99.1MHz R201 19kHz+10Hz
Distortion IF on
99.1MHz
analyzer front end
65d Bf(60dB)
Lech. 1kHz Rch. AC voltmeter
99.1MHz R202
Rch. 1kHz Lch. AC voltmeter
99.1IMHz
switch to AUTO.
99.1MHz
Ext. modulation
65d Bf(60dB)
99.1MHz
Ext. modulation
65d Bf(60dB)
99.1MHz
1kHz, 75kHz devi.
17. 2dBéf (12dB)
Maximum and same
separation
Tuned
TUNED
indicator R101
99. 1MHz
1kHz, 75kHz devi.
16. 2dBf£ (11dB)
indicator
level
AM section
Step AM SG
output
1
522kHz
|Digital
DC
|
OSC
coil
—‘|1.5V+0.1V
Reference
specifications
.
voltmeter
on
RF
block
Tuned
voltage
AM_
522kHz
1.5
+0.4V
(L151)
(Connet
Digital
1611kHz
7.5
+0.5V
DC
voltmeter
to
FM
87.50MHz
2.0
+0.5V
603kHz,60dB/m
|
603kHz
AC
RF
coil
test
point
TP-6)
108.0MHz
7.5
+0.5V
on
RF
block
400Hz
30%
mod.
voltmeter
(L151)
Muting
width
35 +
10kHz
990kHz, 60dB/m 990kHz ae
400Hz 30% mod. Sal nebeE
AM
signal
generator
Output
terminal
antenna
terminal AM
AM
AM LOOP TpP-6
E
LOOP antenna
Digital
oc
voltmeter
—~19—
Muting level FM 12 + 3dB
Auto stop level AM Less than 68dB/m
FM Less than 20dBu
Stereo indicator level 14 + 4dBu
TX-7900/TX-7920
OUTPUT
terminal
FM signal Distortion
generator analyzer
Antenna Terminals
terminal Tp TP-2
oc
voltmeter
(Fig. 1)
Antenna
terminal
TP-4
FM signal = Frequency
generator counter
E
Use the high impedance probe. (10:1)
(Fig. 2)
Terminal
Antenna OUTPUT
EXTumode terminal terminal
Stereo FM signal AC
modulator generator Unit voltmeter
Terminal
TP.4
Frequency Distortion
counter analyzer
<Fig.3>
Adjustment point.
—20—