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KT-1100D
Tuner display unit (X13-5422-72)
DISTANCE display control
fics
DIV meter driver
Converts the
IC9 1/2 (1-3)
AUTO control
(co 2h 7
IC10
DIV meter control
Muting Circuit on Switching
Each key switch receives 5V in "push" status and is latched
in iC 17. (REC CAL circuit uses the exclusive flip-flop.) In the
steady state, the cathode of D54 is pulled up at 5V by R216
(470 kohms).
However, at the moment when each of DIS/
DIR, WID/NAR keys is operated, the voltage is inverted to L
by any of D55 — D58. At this moment, IC16 @ goes high
DIS mute
Le
igs
oy
D46
1clé
(2/6)
Icié
(3/6)
C145
26280
R224
1K
REC
i
REC CAL
Muting output
REC CAL latch output
{REC ON mode, 5V)
Display control for AM mode
Turns ON when in the AM mode and controis WIDE, NARROW,
DIRECT and DISTANCE
indicators OFF.
When turned ON, controls the DISTANCE indicator's OFF.
WIDE display control
When turned ON, controls the WIDE indicator's OFF.
Controls the horizontal axis of T-S (tuning-signal strength) meter.
ee.
2 | UP/DOWN controller
Dividing the puises to UP and DOWN sides depending on the tuning direction.
Qi
Q7
IC2
IC3
Frequency display driver
Status driver for frequency display.
IC7
Dividing, mono-stable
Divides the tuning pulse and maintains for fixed period.
Shifts the center voltage of the tuning meter.
Controls the hold and reset operation of DIV meter.
low-voltage circuit (0 — 5V) to FL drive voltage (O — 18V).
and its voltage is charged in C145 so that IC16 @ gener-
ates the muting signal. In the REC CAL mode, since!C16 @
is fixed at high level forcibly by D54, muting signal is not
generated
even
when
the DIS/DIR
switch
or WID/NAR
switch is changed over. At this time, the muting signal from
DTS will not be accepted (due to D5 1).
DISTANCE
WIDE
8V
5V
v0
Le
2
2
N
=
a 2
&
on
> 2
DISTANCE
sw
ci6o
FRY
(3/4)
<£
R240
Fou, 220x
| -
ae
7
=
054
0. ys0% @
£5
35
3
>
>
&
23
36
3
DS5
ao
Sod
25
aa
eRe
2o
C49
0,1yS0
O
13
beded
=u]
vo
DIRECT
sw
Te
D5é6
1474)
R237 IK CI53 0.01
R243
1K
IcI7
ciso0 Ontp! oO
(74)
R249
Ik
CI56
0.01
R255
IK
WIDE
a
T e d
=
ow
08?
Mieetr
CI51
O.1p50
a)
ot
"a
Ici?
R246
470K
(2/4)
1K
5
R253
"| 220K
| 220k
cis8
O,01
cise
9.01
NARROW
R256
Sw
i
Fig. 1
POWER ON/OFF Muting
In this unit, the power
muting
circuit is designed
as a
2-stage construction.
First after the power is turned ON,
INH, display and.audio muting signal are generated by IC15
sequentially.
And the audio muting voltage is obtained by
using the output voltage of op amp (IC2).
Therefore, even if the mute output (®) of IC15 goes high
(5V), the audio muting is activated when the output © of IC2
is more than 3V (since Q36
turns ON).
Timing chart dia-
grams are shown below.
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