Kenwood KT-7020 Service Manual

KT-7020
maieY
CIRCUIT
DESCRIPTION
CIRCUIT
DESCRIPTION
Port allocation
IC2: CXP5016-216S (X13-633)
Function
Microprocessor IC
On the PC board. shall be ready for being pulled up with a resistor.
Backup (AC OFF) detection terminal. H: AC ON, L: AC OFF. When the
“L" level is detected, the backup status is set and clock is stopped.
(Note) The rise from “L” to “H” shall be faster than the rise of the reset
signal,
Terminal connection diagram & keymatrix connection
ROTARY EN- Rotary encoder output signal input. H: ON, L: OFF.
CODER “B”
Serial shift clock output. H: Normal.
N.C. + PYI/PWMVoo Serial display data output.
ce 2 PY2/WP PYO 63
ROTARY ENCODER “8” 3 PY3/EC RST 62 RESET SIGNAL INPUT N.C.
4 PxO EXTAL 61 x
5
PXt
XTAL
60
4.
194304MHz
KEY
RETURNO~7
|
Key
return
inputs.
H:
Input
present.
L:
Input
absent.
All
terminals
are
6 PX2 INT? 59 ROTARY ENCODER “A” pulled down (by 10K to 100k).
7 Px3 INTZ 58 N.C. Donets
KEY SCAN 1~4 Key scanning signals.
KEY RETURN O 8 POO vroP 57 ve OP 'Y g Sig
KEY RETURN 1 9 PD! To 56
KEY_RETURN
2
40
POZ
Tt
38
SO
Auto-tuning
stop
display
input.
H:
TUNE,
L:
SIGNAL.
KEY RETURN 3
KEY RETURN 4
KEY RETURN 5
KEY RETURN 6
KEY RETURN 7
12
13
14
At)
15 PC3 T6 SO
17
Test mode setting input. H: Normal. L: Test.
Normally pulled up. When testing is required, the TEST terminal is
connected to GND.
N.C. NC
AUTO IF BAND IF band switch input signal for AUTO RF/IF switching mode.
H: Narrow, L: Wide.
PLL C.E. Chip Enable output for PLL IC. Connected to pin 3 CL of LM7001.
parte PLL CLOCK Clock output for PLL IC. Connected to pin 4 CL of LM7001.
| 4 [PuDdata | | 4 [PuDdata | Data output for PLL IC. Connected to pin 5 DATA of LM7001.
Bik KEY SCANS Key scanning signal.
AUTO
STOP
SENS.
SWITCHING
MUTING
Muting
control
terminal.
H:
Muting
ON,
L:
Muting
OFF.
REC
CAL
Conditions
for
Muting
ON:
1)
when
Power
is turned
ON/OFF,
2)
when
the
band
is switched,
3)
during
recalling
a
preset CH,
4)
during
manual
tuning.
5)
during
auto
tuning.
6)
during
IF
band
switching.
7)
during
RF
switching
8)
during
REC
CAL
ON/OFF
switching.
H/L
AUTO
RF
RF
switching
signal
input
in
AUTO
RF/IF
switching
mode.
switching
H:
Direct,
L:
Distance.
AUTO !F BAND SWITCHING
PLL CE
PLL CLOCK
PLL DATA
KEY
SCAN
5
IF
BAND
SWITCHING
RF SWITCHING
AM
MONO
MUTING
AUTO RF SWITCHING
M-—S COMMUNICATION REQUEST A
M-— S COMMUNICATION REQUEST B
Vss
M-—Scommunica- | Data transfer request signal output for M > S display.
tion request H: Communication request, L: Normal.
Functions of diodes and switches
Band
Set
PLL
IC1
(LM7001}
Vss
ivi diate
Switches Receiving Freauency Inter Channel invented IPLL Reference] PLL tnput PLL Output
IB3
B2
B1
BO
Hanae
Seas
ppeauaney
Frequency
|
Terminal
|BO1
(P7}/BO2
(P8}|BO3
(PS)
FMIN
76,0MHz ~ 90.0MH2z 100kHz | — 10.75MHz 25kHz 1/2 prescal-
er outside
531kHz~ 1602kHz 9kHz + 450kHz 9kHz AMIN
87.5MHz~ 108.0MHz} 100kHz | + 10.7MHz 50kHz FMIN
530kHz~ 1610kHz 1OkHz | + 450kHz TOkHz AMIN
87.5MHz~ 108.0MHz| = SOkHz + 10.7MHz | 50kHz FMIN
531kHz~ 1602kHz 9kHz + 450kHz 9kHz AMIN
NC
NC
MONO/ST FM Mono/Stereo reception control output.
H: Mono, L: Stereo.
AM AM pack power control output. H: Power ON, L: Power OFF.
RF SELECTOR RF switching signal output. H: Distance. L: Direct.
Fixed at Distance {H) in other reception modes than FM.
0: Without diode 1: With diode
*:
AM
is
controlled
by
the
microprocessor
!C
(IC2)
in
the
(X13-}
unit.
i
10

Kenwood KT-7020 Specifications

FM Tuner Section

tuning frequency range	87.5 MHz - 108 MHz
usable sensitivity (MONO)	0.95 µV/10.8 dB
total harmonic distortion (MONO)	0.007%
signal to noise ratio (MONO)	92 dB
stereo separation (1 kHz)	65 dB
capture ratio	1.0 dB (WIDE)
alternate channel selectivity (+400 kHz)	60 dB (WIDE)
image rejection ratio (at 98 MHz)	82 dB
IF rejection ratio (at 98 MHz)	110 dB
spurious rejection ratio (at 98 MHz)	105 dB
AM suppression ratio	76 dB
frequency response	20 Hz - 15 kHz, +0.5 dB, -0.5 dB
output level/impedance	0.6 V/3.3 kΩ

AM Tuner Section

tuning frequency range	531 kHz - 1, 602 kHz
usable sensitivity	10 µV (350 µV/m)
signal to noise ratio	55 dB
total harmonic distortion	0.25%
image rejection ratio (Loop)	40 dB
selectivity	30 dB
output level/impedance	0.18 V/3.3 kΩ

General

power consumption	20 W
dimensions (W x H x D)	440 mm x 98 mm x 318 mm
weight	4.3 kg