Dc-Dc Unit - Kenwood TS-990S Service Manual

Ref. No. Use/Function
Q413 Switching
Q414 Switching
Q415 Switching
Q416 Switching
Q417 Switching
Q418 Switching
Q419 Switching
Q420 Switching
Q421 Switching
Q422 Switching
Q423 Switching
Q424 Switching
Q425 Switching
Q426 Switching
Q427 Switching
Q428 Switching
Q430 Switching
D1 Frequency control VCO for SCL01
D2 Switching
D3 Switching
D4 Switching
D8 Switching
Reverse current
D9
prevention
D10~13 RF switching
Reverse current
D14
prevention
D15 VCO tuning
D16~119 RF switching
D20,21 RX mixer
D23 VCO tuning
D24,25 RX mixer
D26 Switching
D401~417 Surg absorption
Reverse current
D418
prevention
COMPONENTS DESCRIPTION
Operation/Condition/Compatibility
Capacitor switching for BPF
(CC8)
Capacitor/coil switching for BPF
(CA2)
Capacitor switching for BPF
(CC9)
Capacitor/coil switching for BPF
(CB4)
Capacitor switching for BPF
(CC10)
Capacitor switching for BPF
(CC11)
Scope attenuator: 9dB ON
Scope attenuator: 6dB ON
Scope attenuator: 3dB ON
Scope attenuator: 9dB ON
Coil switching for BPF (1L)
Coil switching for BPF (2L)
Coil switching for BPF (3L)
Preselector ON
Coil switching for BPF (4L)
Coil switching for BPF (5L)
Preselector ON
ON when main receiver is active
(when SC08M is selected)
ON when sub receiver is active
(when SC11S is selected)
ON when sub receiver is active
(when SC73S is selected)
ON when receiver is active
SEL12 control line
SCIF1 attenuator
SCPUL control line
Variable capacitance for SCLO1
tuning
SCIF1 attenuator
RX Mixer
ON when main receiver is active:
73.095MHz 10.7MHz
Variable capacitance for SCLO2
tuning
RX Mixer
ON when main receiver is active:
10.7MHz 24kHz
Scope ON
Relay (K401-417)
3DB/6DB control line
Ref. No. Use/Function
D419~421 RF switching
D422 Surge absorption
D423~425 RF switching
D426 Surg absorption
D427 Surg absorption
D428 Surg absorption
D429 Surge absorption
D430 Surge absorption
D431 Surge absorption
Reverse current
D601~603
prevention
D607,608 Surge protection
D609 LED (Green)
D610 LED (Yellow)
D611,612 LED (Green)
D613 LED (Yellow)
DC-DC UNIT (X43-3220-00)
Ref. No. Use/Function
IC20 Voltage detactor
IC21 Delayed
IC22 Bus buffer
IC23 Voltage detactor
IC24 AND gate
IC40 3.3V AVR
IC50 Analog switch
IC100 DC/DC converter
IC120 DC/DC converter
IC140 DC/DC converter
IC200 RS-232C driver
IC803 DC/DC converter
IC804 DC/DC converter
Q1,2 Switching
Q20 Switching
Q160,161 Switching
Q270~272 Switching
Q807,808 Switching
Reverse current
D1
prevention
Overvoltage pro-
D2
tection
D20 Zener diode
D21 Zener diode
Reverse current
D40
prevention
TS-990S
Operation/Condition/Compatibility
Preselector attenuator
Relay (K418)
Preselector attenuator
Relay (K419)
Relay (K420)
Relay (K422)
Relay (K421)
Relay (K423)
Relay (K424)
for phone jack data
for USB universal serial data
Key backlight
Key backlight
Key backlight
Multi encoder
Operation/Condition/Compatibility
14V line voltage
D-type fl ip-fl op
14V Voltage detect signal line
Voltage detection (BU5V)
BKC line
3.3V regulator
Fun speed or thermistor voltage
select
8V switching regulator
5V switching regulator
3.3V switching regulator
RS-232C level converter
1.8V switching regulator
1.2V switching regulator
14S power supply switch
Over voltage
33S power supply switch
Multi vibrator for -12V
1.8V power supply switch
From signal revolution pulse of
fan
From signal revolution pulse of
fan
Voltage drop
Over voltage protection
From BU5V power supply
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