Yamaha TX-550 - Tuner Calibration and Adjustments; Pre-Adjustment Setup; Measurement Instrument Glossary

TX-550
ADJUSTMENTS
1 .
Before adjustment
1)
After
the power
switch is pushed
on,
wait
for
5
minutes
befor
measuring
to be
sure
of
the
most
stable
operation.
2)
Adjust
the
OSC
coil
and
IFT with
non-ferrous
screw
driver.
3)
Set
the
switches to
the
following
positions.
TUNING MODE
AUTO
4)
Make the AM
section adjustments after
having
finished
the
FM section
adjustment.
5)
OdBp
=
1
^lV Ex; 60dBp
=
1
mV
XdBp
=
(X + 1 1 .2)dB/ Ex: 70dBp
=
81
.2dB/
(POWER
SUPPLY
CHECK)
Check
that
the
following
voltages are
obtained
respectively
across
each
test
point and
ground
on
tuner
circuit.
Test
Point
Rating or
standard
Remark
+ 12.0 V
(Q29
Emitter)
+ 12.5 V± 0.5
V
Make
sure that AC
line
voltage comes
within:
Models
u,c
G
AC
line
voltage
120
V± 10%
230
V±
10%
+
6.0
V
(Q30
Emitter)
+ 6.0 V+
0.5
V
+ 30.0
V
(Q35
Emitter)
+
28.0
V± 1.0
V
A, B
R
240
V±
10%
110/120/220/240V±10%
-6.0V(D23
Anode)
~6.5
V±0.5V
2.
Measuring
instruments
abbreviation
FM
SG
: FM
signal
generator
SSG
: Stereo
signal
generator
AM
SG :
AM signal
generator
DIST.
M
:
Distortion
meter
FC
: Frequency
counter
ACVM :
AC
voltage
meter
DCVM
; DC
voltage
meter
•
TEST
POINTS
i
ZERO
BALANCE
I
1
STEREO DISTORTION]
FRONT-END IFT
1
SEPARATION
| T1
VR4
VR3
WIDE
VR6
[H
0
JA
[0]L3
VR2
VR1
m
r^VCI
!
mono
DISTORTION
NARROW
DISCRIMINATOR
BALANCE
|
I
SIGNAL
METER
I
^12
V
-6V
+30
V
B-
0-
^
Q29
Q30
Q35
23