Noise Reduction - Kenwood TS-990S Instruction Manual

■ C hanging 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 [
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.
Contents Index

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
] (F3) to allow editing
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.
■ Activating the Noise Reduction for the main band
1 Press [NR1] or [NR2].
■ Activating the Noise Reduction for the sub band
1 Press [NR1/SEL] or [NR2/SEL].
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.
[ESC]
[F1] [F7]
• 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.
• 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.
REJECTING INTERFERENCE 6
[NR1](M)
[NR1](M) [NR2](M) [NR2](M)
[MULTI/CH] [NR1/SEL]
[NR2/SEL]
6-13