Kenwood KT-7020 Service Manual

KT-7020
CIRCUIT DESCRIPTION
IC1: LM7001 (X05-342)
PLL frequency synthesizer
Block diagram
sre
XIN
XOUT o
FMIN
AMIN ©
Terminal description
Pin name Function
XOUT ia)
|
|
|
|
Crystal oscitiator (7.2 MHz).
Data input.
0 {Clock for controtler (400 kHz).
Band data output.
BO1 can be used as a time base output
(8 Hz)
eCloOlNl/alaliatlwlry
Loca! oscillator signal input.
Power supply.
VOD2 for back-up.
Charge pump output.
Power supply.
Data input
Osta input
sititi
CL (PIN@)
DATA {PING}
CE (PING)
INTERNAL OATA
16
Phase Detector
Charge Pump
CIRCUIT DESCRIPTION
118: MC1495L (X05-342}
MPX SUB demodulator
The Direct Pure MPX enables stereo decoding without
causing beat interference. in theory, by linear-multiplying
two analog signals (stereo composite signal and 38 kHz sine
wave sub carrier signal).
This unit provides the linear multiplier with high S/N ratio,
which is designed with the new theory. so that the high
signal-to-noise rationof 94 dB for the MPX unit itself and
the resistance to overmodulation of 400% (dynamic range:
106 dB are realized while the conventinal characteristics
are maintained.
Internal equivalent circuit
KT-7020
2 Output
14 ikKxY)
X input
12 Composite
”
—O 10
300 500 $500
“O13
17

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