Noise reduction, Noise reduction -13 – Kenwood TS-990S User Manual

Page 151

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REJECTING INTERFERENCE 6

6-13

Index

Contents

■ Changing the attenuation level of the Band

Elimination Filter

1 Press and hold [BEF/SEL] (M) or [BEF/SEL] (S)

to open the Band Elimination Filter screen for the

selected band.

2 Press [

] (F2) or [

] (F3) to allow editing

of "Depth" (attenuation level).

3 Press [-] (F4) or [+] (F5), or rotate the MULTI/CH

control to select the amount of attenuation.

• You can select the attenuation level of the band elimination

filter.

• Available range is "20" Hz to "80" dB (in steps of 20 dB).

• The default is "40".

4 Press [ESC] to exit.

Pressing and holding [BEF/SEL] (M) or [BEF/SEL] (S)

closes the Band Elimination Filter screen.

NOISE REDUCTION

The transceiver incorporates two types of noise reduction,

i.e., Noise Reduction 1 (NR1) and Noise Reduction 2

(NR2).

With Noise Reduction 1 selected, spectrum subtraction

noise reduction filter that attaches importance to

readability is activated while the transceiver is receiving

an audio signal in SSB, FM, or AM mode. While the

transceiver is receiving an audio signal in CW, FSK, or

PSK mode, a LSM type noise reduction that emphasizes

the periodic signal is activated instead.

This is suitable for communication in CW mode because

the SPAC system can function during reception to extract

periodic signals using the Noise Reduction 2.

Note:

◆ When Noise Reduction 1 in SSB, FM, or AM mode is supressing

beat signals, wanted signals may also be slightly suppressed. This

is a normal action of Noise Reduction 1, and not a failure.

◆ If Noise Reduction 2 is active while the transceiver is in SSB mode,

the readability of the wanted signal may drop or pulse noise or

distortion may occur.

◆ Noise Reduction 2 cannot be used for FM mode.

[F1] [F7]

[ESC]

[NR2](M)

[NR2](M)

[NR1](M)

[MULTI/CH]

[NR1](M)

[NR1/SEL]

[NR2/SEL]

■ Activating the Noise Reduction for the main band
1
Press [NR1] or [NR2].

• Noise Reduction 1 or Noise Reduction 2 for the main band

is activated or deactivated.

• While Noise Reduction 1 or Noise Reduction 2 is active,

"NR1" or "NR2" appears on the upper left side of the main

screen.

• Press the key again to deactivate the noise reduction for the

main band.

■ Activating the Noise Reduction for the sub band
1
Press [NR1/SEL] or [NR2/SEL].

• Noise Reduction 1 or Noise Reduction 2 for the sub band

becomes active or inactive. While Noise Reduction 1 or

Noise Reduction 2 is active, "NR1" or "NR2" appears on

the upper left side of the main screen.

• Pressing the key again deactivates the noise reduction for

sub band.

Note:

◆ Noise Reduction 1 and Noise Reduction 2 cannot both be enabled

at the same time for both main band and sub band.

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