Audio Peak Filter While In Fsk Mode; Noise Blanker - Kenwood TS-990S Instruction Manual

AUDIO PEAK FILTER WHILE IN FSK MODE

While the transceiver receives a signal in FSK mode,
the audio peak filter allows the mark frequency and
space frequency each to have a peak, thus reducing the
occurrence of garbled characters and increasing the
readability of the signal. The audio peak filter supports not
only high-tone signals with a mark frequency of 2125 Hz
but also low-tone signals with a mark frequency of 1275
Hz. {page 5-46}
[FSK/PSK/REV]
1 Press [FSK/PSK/REV] to select FSK mode.
2 Press [APF/SEL] (M) or [APF/SEL] (S) to enable the
audio peak filter for the selected band.
While the audio peak filter is active, the "APF/SEL" (M) or
"APF/SEL" (S) LED lights green.
Note:
◆ If the shift width for RTTY mode exceeds 170 Hz, the audio peak
filter for the selected band cannot be enabled
◆ The audio filter for use in FSK mode does not process the signal to
be demodulated internally.
Contents Index
[APF/SEL] (M) [APF/SEL] (S)

NOISE BLANKER

The noise blanker suppresses "crunching" pulse noise.
The transceiver incorporates two types of noise blanker;
Noise Blanker 1 (NB1) for analog signal processing, and
Noise Blanker 2 (NB2) for digital signal processing at the
IF stage by means of a DSP. You can select either NB1 or
NB2 as desired depending on the noise status. Both can
be enabled at the same time.
Note:
◆ In FM mode, you cannot use Noise Blanker.
◆ Noise is suppressed more effectively if a larger value is
configured, but there may be some effect on the received signal.
[ESC]
[F1] [F7]
■ A ctivating or deactivating the Noise Blankers for
the main band
1 Press [NB1] or [NB2].
• Noise Blanker 1 or 2 for the main band is activated or
deactivated.
• While Noise Blanker 1 or Noise Blanker 2 is active, "NB1"
or "NB2" appears on the upper left side of the main
screen. While both Noise Blanker 1 and Noise Blanker 2
are active, "NB1 2" appears on the upper left side of the
main screen.
• Pressing the key again deactivates Noise Blanker for the
main band.
■ A ctivating or deactivating the Noise Blankers for
the sub band
1 Press [NB1/SEL] or [NB2/SEL].
• Noise Blanker 1 or Noise Blanker 2 for the sub band
becomes active or inactive.
• While Noise Blanker 1 or Noise Blanker 2 is active, "NB1"
or "NB2" appears on the upper left side of the main
screen. While both Noise Blanker 1 and Noise Blanker 2
are active, "NB1 2" appears on the upper left side of the
main screen.
• To deactivate Noise Blanker 1 or Noise Blanker 2 for the
sub band, press the key again.
■ A djusting the Noise Blanker levels for the main
band.
1 Rotate the NB1 or NB2 control.
• You can adjust the level of NB1 or NB2.
• Rotating the NB1 or NB2 control clockwise suppresses
noise.
REJECTING INTERFERENCE 6
[NB2] [NB1] [NB1] [NB2]
[NB1/SEL] [NB2/SEL]
[MULTI/CH]
6-9