Realistic STA-7 - Page 10

CONNECTION
REPAIR
QI
PRE.AMP OPERATION
CHECK
Set
SELECTOR
Switch
to
PHONO.
Connect
Audio Osc.
to
PHONO
lnPut.
connect
oscilloscope
and
V'T.V.M'
to
TAPE oUT
Jack'
(see
Figure
5')
AUDIO
OSC.
OSCILLOSCOPE
SET
Figure
5
Equalization
Curve
response
(RIAA
Curve)
Check
for
proper
PHONO
(See
Figure
6).
I+13.r'l
Figure
6
20
-3pHgor.""r,*,
(1)
check
rR2o1, 2m
(rJ;Lf
irol.
(21
Check
C209,C211,R219,R217
(L
ch)
and C210,C212,R22O^R218
(R
ch).
(3)
Check
Pre-Amp
circuit.
Equalization Response at 100
Hz
does
not
fall
within
+13.11
r-2
dB and at
'10
kHz
does
not fall within
-13.75
-+.2
dB.
Equalization
Response
falls within
+13.11
L2dB
at
100
Hz
and
-13.75
+.2
dB at 10
kHz.
Proceed
to
next
section.
(3)
TONE CONTROL OPERATION
CHECK
Same
Equipment
Connection
as
Figure
3.
a
36
U
6
U
E
t
-,o
I
l-
r3.751
-15
t5
to
o
-to
-
10-