Kenwood TS-990S Service Manual

TS-990S
55
COMPONENTS DESCRIPTION
Ref. No. Use/Function Operation/Condition/Compatibility
D32,33 RX 2nd mixer
Recieving mixer (8.248MHz

24kHz)
D34~39 Surge absorption Relay (K11~K16)
D40,41 Clipper FM demodulator IC input
D42,43 Switching FM wide/narrow switching
D44 Switching
ON when 15kHz IF fi lter is se-
lected
D45 Switching
ON when 6kHz IF fi lter is se-
lected
D46 Switching
ON when 2.7kHz IF fi lter is se-
lected
D47 Switching
ON when 500Hz IF fi lter is select-
ed
D48 Switching
ON when 270Hz IF fi lter is select-
ed
D49 Switching
ON when additional IF fi lter is
selected
D50 Surge absorption Relay (K17)
D52, 53
Reverse current
prevention
Control line of Q51
D54, 55
Reverse current
prevention
Control line of Q14
D56,57 Switching
ON when BPF of 35~40MHz is
selected
D501~506 Surge absorption Relay (K501~K506)
D507 Switching
ON when BPF of 14.5~18.5MHz
is selected
D508 Switching
ON when BPF of 21.5~26.5MHz
is selected
D509 Switching
ON when BPF of 26.5~35MHz is
selected
D510 Switching
ON when BPF of 46.5~60MHz is
selected
D511 Switching
ON when BPF of 4.1~6MHz is
selected
D512 Switching
ON when BPF of 7.5~10.5MHz is
selected
D513 Switching
ON when BPF of 40~46.5MHz is
selected
D514 Switching
ON when BPF of 4.1~6MHz is
selected
D515 Switching
ON when BPF of 7.5~10.5MHz is
selected
D516 Switching
ON when BPF of 14.5~18.5MHz
is selected
D517 Switching
ON when BPF of 21.5~26.5MHz
is selected
D518 Switching
ON when BPF of 26.5~35MHz is
selected
D519 Switching
ON when BPF of 40~46.5MHz is
selected
D520 Switching
ON when BPF of 46.5~60MHz is
selected
TX-RX UNIT (X57-827X-XX)
Ref. No. Use/Function Operation/Condition/Compatibility
IC51 Shift register
Q1: SBPF[13] “H” when BPF of
50M band is selected (TX only)
Q2: SBPF[12] “H” when BPF of
30~60M band is selected
Q3: SBPF[11] “H” when BPF of
28M band is selected
Q4: SBPF[10] “H” when BPF of
21M band is selected
Q5: SBPF[9] “H” when BPF of
14M band is selected
Q6: SBPF[8] “H” when BPF of
11M band is selected
Q7: SBPF[7] “H” when BPF of
10M band is selected
Q8: SBPF[6] “H” when BPF of
7M band is selected
IC52 Shift register
Q1: SBPF[5] “H” when BPF of
5M band is selected
Q2: SBPF[4] “H” when BPF of
3.5M band is selected
Q3: SBPF[3] "H" when BPF of
1.8M band is selected
Q4: SBPF[2] “H” when BPF of
BC band (522k~1.705MHz) is
selected
Q5: SBPF[1] “H” when BPF of
BC band (30~522kHz) is selected
Q6: S6DB “L” when sub RX 6dB
or 18dB attenuator ON
Q7: S12DB “L” when sub RX
12dB or 18dB attenuator ON
Q8: S455FIL “L” when 455kHz
FM 9kHz (narrow) fi lter is se-
lected
IC53 Shift register
Q1: SFIL[1] “H” when 15kHz IF
fi lter is selected
Q2: SFIL[2] “H” when 6kHz IF
fi lter is selected
Q3: SFIL[3] “H” when 2.7kHz IF
fi lter is selected
Q4: SFIL[4] “H” when 500Hz IF
fi lter is selected
Q5: SRXFM “H” when sub RX
FM mode is selected
Q6: TXFM “H” when TX FM
mode is selected
Q7: SHFRGC Reserved
Q8: S50RGC Reserved
IC54 Shift register
Q1: SPRE[1] “H” when sub
receiving preamplifi er is ON
Q2: SPRE[2] “H” when sub
receiving 21.5~60MHz and pre-
amplifi er is ON
Q3: 1STIF “H” when sub RX 1st
IF of 73.095MHz is selected
Q4: DRVO “H” when drive out-
put is selected
Q5: AMC “H” when AM TX is
selected (for 50msec)
Q6: RLSW “H” when LINEAR is
“H”

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