Kenwood TS-990S Service Manual

TS-990S
41
COMPONENTS DESCRIPTION
Ref. No. Use/Function Operation/Condition/Compatibility
Q413 Switching
Capacitor switching for BPF
(CC8)
Q414 Switching
Capacitor/coil switching for BPF
(CA2)
Q415 Switching
Capacitor switching for BPF
(CC9)
Q416 Switching
Capacitor/coil switching for BPF
(CB4)
Q417 Switching
Capacitor switching for BPF
(CC10)
Q418 Switching
Capacitor switching for BPF
(CC11)
Q419 Switching Scope attenuator: 9dB ON
Q420 Switching Scope attenuator: 6dB ON
Q421 Switching Scope attenuator: 3dB ON
Q422 Switching Scope attenuator: 9dB ON
Q423 Switching Coil switching for BPF (1L)
Q424 Switching Coil switching for BPF (2L)
Q425 Switching Coil switching for BPF (3L)
Q426 Switching Preselector ON
Q427 Switching Coil switching for BPF (4L)
Q428 Switching Coil switching for BPF (5L)
Q430 Switching Preselector ON
D1 Frequency control VCO for SCL01
D2 Switching
ON when main receiver is active
(when SC08M is selected)
D3 Switching
ON when sub receiver is active
(when SC11S is selected)
D4 Switching
ON when sub receiver is active
(when SC73S is selected)
D8 Switching ON when receiver is active
D9
Reverse current
prevention
SEL12 control line
D10
~ 13 RF switching SCIF1 attenuator
D14
Reverse current
prevention
SCPUL control line
D15 VCO tuning
Variable capacitance for SCLO1
tuning
D16
~ 119 RF switching SCIF1 attenuator
D20,21 RX mixer
RX Mixer
ON when main receiver is active:
73.095MHz

10.7MHz
D23 VCO tuning
Variable capacitance for SCLO2
tuning
D24,25 RX mixer
RX Mixer
ON when main receiver is active:
10.7MHz

24kHz
D26 Switching Scope ON
D401~417 Surg absorption Relay (K401-417)
D418
Reverse current
prevention
3DB/6DB control line
Ref. No. Use/Function Operation/Condition/Compatibility
D419~421 RF switching Preselector attenuator
D422 Surge absorption Relay (K418)
D423~425 RF switching Preselector attenuator
D426 Surg absorption Relay (K419)
D427 Surg absorption Relay (K420)
D428 Surg absorption Relay (K422)
D429 Surge absorption Relay (K421)
D430 Surge absorption Relay (K423)
D431 Surge absorption Relay (K424)
D601~603
Reverse current
prevention
for phone jack data
D607,608 Surge protection for USB universal serial data
D609 LED (Green) Key backlight
D610 LED (Yellow) Key backlight
D611,612 LED (Green) Key backlight
D613 LED (Yellow) Multi encoder
DC-DC UNIT (X43-3220-00)
Ref. No. Use/Function Operation/Condition/Compatibility
IC20 Voltage detactor 14V line voltage
IC21 Delayed D-type fl ip-fl op
IC22 Bus buffer 14V Voltage detect signal line
IC23 Voltage detactor Voltage detection (BU5V)
IC24 AND gate BKC line
IC40 3.3V AVR 3.3V regulator
IC50 Analog switch
Fun speed or thermistor voltage
select
IC100 DC/DC converter 8V switching regulator
IC120 DC/DC converter 5V switching regulator
IC140 DC/DC converter 3.3V switching regulator
IC200 RS-232C driver RS-232C level converter
IC803 DC/DC converter 1.8V switching regulator
IC804 DC/DC converter 1.2V switching regulator
Q1,2 Switching 14S power supply switch
Q20 Switching Over voltage
Q160,161 Switching 33S power supply switch
Q270 ~ 272 Switching Multi vibrator for -12V
Q807,808 Switching 1.8V power supply switch
D1
Reverse current
prevention
From signal revolution pulse of
fan
D2
Overvoltage pro-
tection
From signal revolution pulse of
fan
D20 Zener diode Voltage drop
D21 Zener diode Over voltage protection
D40
Reverse current
prevention
From BU5V power supply

Kenwood TS-990S Specifications

General

Receiver Type	Triple Conversion Superheterodyne
Antenna Tuner	Built-in automatic antenna tuner
DSP	Yes
IF DSP	Yes
Modes	SSB, CW, AM, FM
Display	7-inch TFT color LCD
Weight	25 kg (55.1 lbs)
Antenna Connectors	SO-239
Power Supply	13.8V DC