Realistic STA-115 - Page 25

REPAI R
r----
------i
,c_[e_c\_s!01111t9-ltl_ois91ltto:
_(lpgt_srg1{._!1v_,IY
lte$St{!9.99]tl[zll
"
*should
be
higher
than
66 dB.**
(1)
Readjust
RF/lF.
(See
page
30for FM RF
&
lF
ALIGNMENT.)
(2)
Check FM
RF/lF circuits.
i
I
l
l
I
:
Signal-to-Noise ratio is lower than
66dB.
Signal-to-Noise ratio is higher than
66
dB.
I----
--
-
- -
--'l
;Check
the
signal
LED meter.
i
;
N;;',s;;rl LED ;;i.;;;;,
not
risht.**
*+
200pV/m
lnput
=
All LEDs light
up.**
(1)
Verify LEDs
function
on AM;
return to
FM.
(2)
Readjust
VR202 for
all
LEDs lit at
200pV/m
input.
(3)
Check
FM lF circuit.
Signal
LED
meters
do not
light correctly.
Signal
LED meters light
correctly.
f-_t--.-:---
---.--.-l
;Check
FM
75psec de-emphasis
i
[9P9]-s99!1-e:
-------
--
--]
*
*See
Figure
22"
*
(1
)
Check and/or
change value
of
C229
(Lch),
C230
(Rch).
(Pin
8,
10 of 1C202)
s
rG
NAl,.
STRENGTH
:
IUUUI__IL-II
NO
SIGNAL INPUT
SIGNAL
STRENGTH
ffi
INPUT
20O
1tv
/
m
Figure
21
400 rok
-
AUOIO FREOUENCY(Hz)
DE-EMPHASIS
CURVE
@
z
9
E
I-,..,
FM
75
psec
response at 10
kHz
modu-
lation does not fall
within
-13.65
t
1.5
dB.
Figure 22
FM
75
psec
response at 10 kHz modulation
falls
within
-13.65
t'1.5
dB.
isl
g{t
r ll,e
J ryT
[.lo.
I'J
q
ri t1t-u
ti)-i
**
lnput
4.0
-
10.OpV
(Nominal
7.0pV)"*
Readjust VR201
(Pin
13, 1C201).
Muting level is not 4.0
-
10.0pV.
Muting level is 4.0
-
10.0pV.
Proceed
to
next
section.
-25-