Kenwood TS-990S Service Manual

TS-990S
52
COMPONENTS DESCRIPTION
Ref. No. Use/Function Operation/Condition/Compatibility
Q303~306 Switching Touch panel SW (X1/Y1/Y2/X2)
Q307 Switching Touch panel SW pull up on
Q308 Switching Touch panel SW press
D1~8
Reverse current
prevention
For key matrix
D9 LED (Green) Key backlight
D10 LED (Green) SPLIT
D11 LED (Green) Key backlight
D12 LED (Yellow) SPLIT
D13~18 LED (Green) Key backlight
D19
Reverse current
prevention
Reduced voltage detection inter-
rupt for BKC
D20~22 LED (Green) Key backlight
D23 LED (Green) Main busy
D24 LED (Green) Key backlight
D25 LED (Red) Main TX
D26 LED (Green) Key backlight
D27 LED (Green) Sub busy
D28 LED (Green) Key backlight
D29 LED (Red) Sub TX
D31 LED (Yellow) HI/LO encoder
D32,34 LED (Green) Key backlight
D36 LED (Yellow) Key backlight
D37 ~ 42 LED (Green) Key backlight
D43 LED (Red) Key backlight
D44 LED (Green) Key backlight
D45,46 LED (Yellow) Key backlight
D47 ~ 51 LED (Green) Key backlight
D52 LED (Yellow) Key backlight
D53,56
Reverse current
prevention
MIC data line
D54 Poly-switch Current limit for MIC supply (8V)
D55
Reverse current
prevention
for MIC supply (8V)
D61 ~ 63 LED (Green) Key backlight
D301,303 Switching
Catch diode for main and sub
display backlight
D302,306
Reverse current
prevention
Main and sub display backlight
D307,308 Surge protection Touch panel signal line
D501 ~ 504 LED (Green) Key backlight
RX UNIT (X55-313X-XX)
Ref. No. Use/Function Operation/Condition/Compatibility
IC1 D/A converter
Ao1: Reserve
Ao2: MIFGC Main RX IF gain
control voltage
Ao3: MNBL Main NB level con-
trol voltage
Ref. No. Use/Function Operation/Condition/Compatibility
IC1 D/A converter
Ao4: Reserve
Ao5: Reserve
Ao6: Reserve
Ao7: Reserve
Ao8: Reserve
IC2 Shift register
Q1: MBPF14 “H” when BPF
of 35~40MHz or 46.5~60MHz is
selected
Q2: MBPF13 “H” when BPF of
40~46.5MHz band is selected
Q3: MBPF12 “H” when BPF of
26.5~35MHz is selected
Q4: MBPF11 “H” when BPF of
21.5~26.5MHz is selected
Q5: MBPF10 “H” when BPF of
18.5~21.5MHz is selected
Q6: MBPF9 “H” when BPF of
14.5~18.5MHz is selected
Q7: MBPF8 “H” when BPF of
10.5~14.5MHz is selected
Q8: MBPF7 “H” when BPF of
7.5~10.5MHz is selected
IC3 Shift register
Q1: MBPF6 “H” when BPF of
6~7.5MHz is selected
Q2: MBPF5 “H” when BPF of
4.1~6MHz is selected
Q3: MBPF4 “H” when BPF of
2.5~4.1MHz is selected
Q4: MBPF3 “H” when BPF of
1.705~2.5MHz is selected
Q5: MBPF2 “H” when BPF of
522k~1.705MHz is selected
Q6: MBPF1 “H” when BPF of
30~522kHz is selected
Q7: M6DB “L” when 6dB attenu-
ator ON
Q8: M12DB “L” when 12dB at-
tenuator ON
IC4 Shift register
Q1: MFIL1 “H” when 15kHz IF
fi lter is selected
Q2: MFIL2 “H” when 6kHz IF
fi lter is selected
Q3: MFIL3 “H” when 2.7kHz IF
fi lter is selected
Q4: MFIL4 “H” when 500Hz IF
fi lter is selected
Q5: MFIL5 “H” when 270Hz IF
fi lter is selected
Q6: MFIL6 “H” when additional
IF fi lter is selected
Q7: MPRE1 “H” when preamp
(PREAMP1) and post amp are
ON
Q8: MPRE2
“H” when preamps
(PREAMP2) and post amp are ON
IC5 Shift register
Q1: MHFRGC “H” when 6dB IF
attenuator is ON
Q2: M50RGC “H” when 10dB IF
attenuator is ON
Q3: M455FIL “L” when 455kHz
FM narrow fi lter is selected
Q4: MRXFM “H” when RX FM
mode is selected

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