Kenwood TS-990SHF manual Advanced AGC control, fusing together digital and analogue

Page 10

HF/50MHz TRANSCEIVER TS-990S

DSP/IF filter

Equipped with dedicated DSP for the main receiver, sub-receiver, and band scope

Extensive interference elimination and noise reduction functions

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-

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.)

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.

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-

(dB)

-20

 

WIDTH

You can avoid neighbouring signals by varying the bandpass width.

SHIFT

If the interference is on one side only, you can shift the central frequency without changing bandwidth.

ing interference

Amplitude

-40

 

signals, even if it

-60

 

 

-80

cuts down some of

 

 

 

For main IF DSP, transmission unit

For sub IF DSP, every kind of signal processing

For band scope

ADSP-21363 clock @333 MHz

ADSP-21369 clock @260 MHz

ADSP-21363 clock @333 MHz

WIDTH

Intended

signal

SHIFT

Target

signal

the target signal.

-1,000

-500

0

500

1,000

 

 

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

Advanced AGC control, fusing together digital and analogue

The reception sound quality of SSB and CW is not

significant role as well. The opinion of many of our

solely determined by audio frequency and filter

fans that “even for long periods of time they never

delay properties. AGC characteristics play a very

get tired of listening” is due to the characteristics

IF AGC control block diagram

 

 

of Kenwood’s AGC . The

CONT

 

TS-990S goes a long way

 

 

 

SOFT-ATK

Demod

 

 

 

 

 

 

RX IF

IF ADC

Digital NB

 

RX Audio

in helping further refine the

Analog

 

 

AGC DET

AGC DET

Kenwood tone by innovating

AGCV

AGCV DAC

AGC DET

 

 

not only the AGC control al-

 

 

 

 

 

 

 

IF Filter

 

 

 

ATK/REL

AutoManual Notch

 

gorithm on the DSP but also

 

 

Band Elimination Filter

 

 

 

OUT Band

 

 

 

 

 

Manager

 

 

the analog AGC unit as well.

 

 

 

 

 

Exacting chassis design for realizing quality sound

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 narrow or wide,

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

 

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.

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.

ϕ 77mm

Top plate oscillation

Built-in speaker

simulation example

can be changed

 

0

 

 

 

 

 

 

manually, depend-

(dB)

-20

 

 

 

 

 

Amplitude

-40

 

 

ing on the state of

 

 

-60

 

 

interference.

 

 

 

-80

 

 

 

 

-1,000 -500

0

500 1,000

 

 

 

Frequency (Hz)

 

<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

Image 10 Contents
Hertfordshire WD18 9EB, United Kingdom TS-990S Page TS-990S Repeated innovation turns the tradition into a legend TS-990S NEW Main Receiver Newly developed mixer contributes to achieving +40 dBm IP3HF/50MHz Transceiver TS-990S Sub-receiver, which incorporates the TS-590S receiver Sub ReceiverTriple DSP Roofing filter, 500 Hz, 2.7 kHzAdvanced AGC control, fusing together digital and analogue Exacting chassis design for realizing quality soundTransmit Thermal simulation exampleMain display Sub band display monitors the target signal itselfDual display Main display example viewsControl New split function allows you to use quick settingsNew frequency function can be operated intuitively Remote control TS-990S from your PC Firmware updates by USB flash drive or USB cableData mode supported by external I/O switching Kenwood SKY Command SystemDimensions Front/Rear PanelSpecifications Main Options
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