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Equipped with dedicated DSP for the main receiver, sub-receiver,
and band scope
Kenwood continues to provide quality sound trans-
mission that is unattainable through analog circuits.
By loading the world-premiere DSP on the TS-950
and achieving IF AGC control on the TS-870 by
using DSP for the first time for amateur wireless
devices. As a culmination of the foregoing develop-
For main IF DSP, transmission unit
For sub IF DSP, every kind of signal processing
ADSP-21363 clock @333 MHz
ADSP-21369 clock @260 MHz
Advanced AGC control, fusing together digital and analogue
The reception sound quality of SSB and CW is not
solely determined by audio frequency and filter
delay properties. AGC characteristics play a very
IF AGC control block diagram
SOFT-ATK
RX IF
IF ADC
Digital NB
AGC DET
Analog
AGCV DAC
AGC DET
AGCV
IF Filter
AutoManual Notch
OUT Band
Band Elimination Filter
ATK/REL
Manager
Exacting chassis design for realizing quality sound
The sound quality of the built-in speakers is largely determined by
the chassis structure. With the TS-990S, we have been able to mini-
mize unnecessary chassis vibration through multiple simulations
from the conceptual phase. The Kenwood tone is supported not only
by circuits and DSP but also by exact chassis design.
ments, three DSP units are used, one on each major
block of the TS-990S. By distributing the signal pro-
cessing of the main IF, band scope, and sub-IF, we
have realized ample digital signal processing. (FM
mode is AF DSP processing.)
For band scope
ADSP-21363 clock @333 MHz
significant role as well. The opinion of many of our
fans that "even for long periods of time they never
get tired of listening" is due to the characteristics
o f K e n w o o d 's A G C . T h e
TS-990S goes a long way
Demod
CONT
in helping further refine the
RX Audio
Kenwood tone by innovating
AGC DET
not only the AGC control al-
gorithm on the DSP but also
the analog AGC unit as well.
ϕ
77mm
Top plate oscillation
Built-in speaker
simulation example
HF/50MHz TRANSCEIVER TS-990S
Extensive interference elimination
and noise reduction functions
IF filter bandwidth variability
You can vary DSP filter bandwidth and eliminate ex-
tensive interference depending on use and condition.
You can operate it as a HI CUT/LOW CUT function
in SSB/AM/FM mode, and WIDTH/SHIFT function
in CW/FSK/SSB-DATA transmission mode.
WIDTH
SHIFT
You can avoid neighbouring
If the interference is on one side only,
signals by varying the
you can shift the central frequency
bandpass width.
without changing bandwidth.
WIDTH
SHIFT
Intended
Target
signal
signal
IF filter A/B/C one-touch switch instantly
It is possible to preset a maximum of three IF filter
switch and switch instantly at any time. Set for
n a r r o w o r w i d e ,
such a function is
convenient for com-
petitions requiring
quick operations.
IF notch
You can eliminate overpowering interference signals
with a notch filter and catch intended weak signals.
You can switch between the IF auto notch and the
manual notch that
IF Manual Notch
BW 400Hz / 800Hz
can be changed
0
manually, depend-
-20
-40
ing on the state of
-60
interference.
-80
-1,000
-500
0
500
1,000
Frequency (Hz)
DSP / IF filter
Band elimination filter function
The filter is capable of varying the stopband band-
width and the amount of loss. When signals that
interfere with the target signal multiply, this is a
convenient func-
Band Elimination Filter
tion for operations
0
such as dampen-
-20
ing interference
-40
-60
signals, even if it
-80
cuts down some of
-1,000
-500
0
500
1,000
the target signal.
Frequency (Hz)
The noise blanker function (NB1/NB2) is
equipped with digital/analogue 2 format
Equipped with an analogue noise blanker (NB1)
which is considered being effective against weak
noise, and a digital noise blanker (NB2). Choose the
NB1 or NB2 based on noise type and reception con-
dition. With NB1, stable noise reduction is possible
without depending on reception bandwidth. NB2 is
effective against noise that cannot be tracked by an
analogue noise blanker. Plus, both the NB1 and NB2
can be used simultaneously with the TS-990S.
DSP-based noise reduction function (NR1/NR2)
The device is also equipped with two types of noise
reduction format—NR1 and NR2. An optimal noise
reduction format is applied to each reception mode
for NR1. And for NR2, SPAC method is applied
which is more effective in CW operation.
<
Other extensive interference elimination and noise
>
reduction functions
Beat cancel function (BC1/BC2)
The beat cancel function is effective against relatively weak, multiple beats,
whereas the IF auto notch is effective against strong beats.
Audio peak filter
You can vary bandpass width of pitch tone when there are carrier receptions
like CW and FSK. FSK is compatible with mark and space frequencies.
9
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