Kenwood TS-830S Service Manual page 6

CIRCUIT DESCRIPTION
BCD W T SEGMENT OUT DIGIT OUT
(tz)W)(+4)(l5)
6)
(6) V l
(a
(9)(lo(lil
( s o -
A B C D
a b c d o l a Ds[k D4Da Dzlk
v?/r"-[
Nc
uP/ D OWN.
SET ZERO
L ZB
CARRY
38 COUNT
INHIBIT
1 ;
6
37 COUNT
MULTIPLEXER
SEG
BCD IN
! I
COMPARATOR
I I
t t t f t t t
I
6 DIGIT BCD
r
1
I
UP/DOWN(4)
COUNT INHlBlT(38)
COUNT(37)
CLEAR(2t)
l a -
11
32
-
LOAD COUNTER
12 31
-
LOAD
REGISTER
STORE
-
1 6
CD
-
1 7
24
-
EQUAL
CA
-
20
23
-
Vss
CLEAR
-
21
22
-
SCAN
6 DIGIT REGISTER
I
t t t t t t t
I
1
6 DlGlT
MULTIPLEXER
I 1
6 DlGlT MULTIPLEXER
I
I
CA CB CC CD
'
RA RE RC RD
'
I321 (20) (f9) (18) (17) 131 I (56) (35) 04) (33)
LOAD COUNTER COUNTER BCD IN LOAD REGISTER REGISTER BCD IN
Fig. 4 TC5070P (Counter unit, Q5)
SCAN
2 0-2
5KHz
Fig. 5 TC5070P timing chart
Q5 (TC5070P)
IS
a presettable, 6-dlglt BCD counter whlch
Incorporates a 6-diglt latch, 6 - d i g ~ t dynamic drive d i g ~ t a l
counter, and 7-segment decoder/driver Band ~nformation
suppl~ed from the RF unlt
IS
applied to a diode matrix to
preset the 1 0 0 kHz, 1 MHz. and 1 0 MHz digits. Preset
values are given In Figure 3
For Instance to preset 1 4 . 0 0 0
MHz, with a 500' kHz counter Input s~gnal, 1 0 MHz value
IS
preset to 1, 1 MHz to 3, and 1 0 0 kHz to 5, the 5 0 0 kHz
counter input signal subtracted from 1 4 . 0 0 0 MHz. (If no
counter input signal were present, 1 3 . 5 0 0 NlHz would be
displayed.) Q5 supplies the display tube drivers with 7-seg-
ment information and dynamic drive control signals t o light
the fluorescent display tube.
Fig. 6 Indicating tube 9-BT-12
In the counter unit, a diode matrix generates frequency
~ I V I -
sion lnformation and supplies the PLL unlt wlth thls Informa-
tion If the PLL unlocks, a BLK (Blanking Low) slgnal will be
applled to the digit drive IC ( Q 1 1 ) to blank the fluorescent
display tube Normally, flve hlgh-order digits are displayed
D H
(digital
hold) locks the display from changing Digital
hold
I S
accomplished by presetting the latch pulse at Low
level