Kenwood TS-990S Service Manual

TS-990S
40
COMPONENTS DESCRIPTION
ACCESSORY UNIT (X42-3430-00)
Ref. No. Use/Function Operation/Condition/Compatibility
IC1 DDS
SCLO1 reference signal genera-
tion
IC2 DDS
SCLO2 reference signal genera-
tion
IC3 DDS SCLO3 signal generation
IC4 PLL SCLO1 control
IC5 Bus buffer Level shift
IC6 PLL SCLO2 control
IC7,8 Bus buffer Level shift
IC9 Amplifi er SCIF3 gain adjustment
IC10 Buffer amplifi er SCLO1 reference signal amplifi er
IC11,12 5V AVR 5V regulator
IC401 EEPROM
Adjustment data record for prese-
lector
IC402 Shift register
Q1 : CA1
Q2 : CA2
Q3 : CB1
Q4 : CB2
Q5 : CB3
Q6 : CB4
Q7 : CC1
Q8 : CC2
IC403 Shift register
Q1 : CC3
Q2 : CC4
Q3 : CC5
Q4 : CC6
Q5 : CC7
Q6 : CC8
Q7 : CC9
Q8 : CC10
IC404 Shift register
Q1 : CC1
Q2 : 1L
Q3 : 2L
Q4 : 3L
Q5 : 4L
Q6 : 5L
Q7 : 3DB
Q8 : 6DB
Q1 Switching
IF switching, ON when main
receiver is active (when SC08M
is selected)
Q2 Switching
IF switching, ON when sub
receiver is active (when SC11S is
selected)
Q3 Switching
IF switching, ON when main
receiver is active (when SC08M
is selected)
Q4 Switching
IF switching, ON when sub
receiver is active (when SC11S is
selected)
Q5 Switching
IF switching, ON when sub
receiver is active (when SC73S is
selected)
Q7 Amplifi er Common base, for 8MHz
Q8 Amplifi er Common base, for 11MHz
Ref. No. Use/Function Operation/Condition/Compatibility
Q9 Switching
IF switching, ON when sub
receiver is active (when SC73S is
selected)
Q11 Amplifi er Input amplifi er for 40MHz
Q12 Amplifi er Common base, for 73MHz
Q14~16 Amplifi er Input amplifi er for 40MHz
Q17 ~ 20 RX mixer
Receiving mixer
Main receiver:
SC08M

73.095MHz
Sub receiver:
SC11S

73.095MHz
Q21,22 Switching
Power supply control for SCLO1,
for 8A
Q23~25 Amplifi er DDS output buffer amplifi er
Q26,27 Switching
Power supply control for SCMIX1,
for 14S
Q29 Amplifi er Amplifi er for PLL REF (8.4MHz)
Q30 Amplifi er Amplifi er for SCLO3 (10.676MHz)
Q31 Switching Scope attenuator: 0dB ON
Q32 Switching Scope attenuator: -10dB ON
Q33 Switching Scope attenuator: -20dB ON
Q37 Switching Scope attenuator: -30dB ON
Q38 Amplifi er Amplifi er for loop fi lter
Q39 Amplifi er SCIF1 amplifi er
Q40 Buffer amplifi er PLL IC f-in
Q41 Amplifi er Amplifi er for loop fi lter
Q43 Amplifi er Amplifi er for loop fi lter
Q44,45 Amplifi er SCIF2 amplifi er
Q50,51 Switching 5V switch
Q401 Switching Preselector ON
Q402 Switching
Capacitor switching for BPF
(CC1)
Q403 Switching
Capacitor switching for BPF
(CC2)
Q404 Switching
Capacitor switching for BPF
(CC3)
Q405 Switching
Capacitor switching for BPF
(CC4)
Q406 Switching
Capacitor switching for BPF
(CC5)
Q407 Switching
Capacitor/coil switching for BPF
(CB1)
Q408 Switching
Capacitor switching for BPF
(CC6)
Q409 Switching
Capacitor/coil switching for BPF
(CA1)
Q410 Switching
Capacitor/coil switching for BPF
(CB2)
Q411 Switching
Capacitor/coil switching for BPF
(CC7)
Q412 Switching
Capacitor/coil switching for BPF
(CB3)

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