Kenwood TS-990S Service Manual

TS-990S
6
CIRCUIT DESCRIPTION
●
IF=8.248MHz
Frequency: 0.03 ~ 60MHz
MAIN RX
MLO1
DDS AD9951 (MDEN1)
USB USB-DATA LSB LSB-DATA CW CW-R
RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX
Mode offset 1
+(MDSPFC) +(MDSPFC) +(MDSHIFT) +(MDSHIFT) -(MDSPFC) -(MDSPFC) -(MDSHIFT) -(MDSHIFT) +(CW SHIFT) +(CW SHIFT) - (CW SHIFT) - (CW SHIFT)
MAIN RIT (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT)
MAIN CAR
IF8M_2.7k +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1)
IF8M_500 +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2)
IF8M_270 +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3)
MAIN RX
MLO1
DDS AD9951 (MDEN1)
PKS PKS-R FSK FSK-R AM FM (FM-DATA)
RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX
Mode offset 1 0000
-(FSK SHIFT/2) -(FSK SHIFT/2) -(FSK SHIFT/2) -(FSK SHIFT/2) 00
MAIN RIT (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT) (

MRIT)
MAIN CAR
IF8M_2.7k +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1) +(MCAR1) -(MCAR1)
IF8M_500 +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2) +(MCAR2) -(MCAR2)
IF8M_270 +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3) +(MCAR3) -(MCAR3)
MLO2
DDS AD9951 (MDEN1)
USB USB-DATA LSB LSB-DATA CW CW-R
RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX
Mode offset 1
+(MDSPFC) -(MDSPFC) +(MDSHIFT) -(MDSPFC) -(MDSPFC) +(MDSPFC) -(MDSHIFT) +(MDSPFC) +(CW SHIFT) -(CW SHIFT) -(CW SHIFT) +(CW SHIFT)
MAIN CAR
IF8M_2.7k +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1)
IF8M_500 +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2)
IF8M_270 +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3)
MLO2
DDS AD9951 (MDEN1)
PKS PKS-R FSK FSK-R AM FM (FM-DATA)
RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX RX

26.5 26.5

RX
Mode offset 1 0 0
00 00
MAIN CAR
IF8M_2.7k +(MCAR1) +(MCAR1) +(MCAR1) +(MCAR1)
IF8M_500 +(MCAR2) +(MCAR2) +(MCAR2) +(MCAR2)
IF8M_270 +(MCAR3) +(MCAR3) +(MCAR3) +(MCAR3)
(

MRIT): Main RIT frequency variable amount (–9.99~+9.99kHz)
(FSK SHIFT): FSK shift width frequency (170Hz, 200Hz, 425Hz, 850Hz, and initial value: 170Hz)
(CW SHIFT): CW shift amount
CAR correction: SSB IF-Filter adjustment range (The range is set to zero when an additional roofi ng fi lter is used.)
(MCAR1): Main, IF fi lter (2.7kHz) correction value
(MCAR2): Main, IF fi lter (500Hz) correction value
(MCAR3): Main, IF fi lter (270Hz) correction value
(MDSPFC): Varied with the DSP fi lter set value
(MDSHIFT): DATA mode shift width frequency set value
Table 1 MLO1/MLO2 frequency shift data
2. Transmission and Sub Receiver Blocks
2-1. Frequency Confi guration
When transmitting in FM mode, it works in double conver-
sion, and when transmitting in AM, SSB, CW, FSK or PSK
mode, it works in triple conversion.
While sub receiving, the 1st IF works in 73.095MHz triple
conversion. In modes other than FM, the 3rd IF works in
24kHz, and the IF signal is converted by an A/D converter
(ADC) and is applied to DSP. In FM mode, the audio signal
is discriminated by the FM IC, and is converted into the digi-
tal signal by an ADC and then is applied to the DSP. Under
the following conditions, the 1st IF of the sub receiver block
works in 11.374MHz double conversion.
1) Modes other than AM or FM
2) 1.8/ 3.5/ 7/ 14/ 21MHz amateur bands
3) DSP fi lter's bandwidth is 2.7kHz or lower

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