If Noise Blanker ( Nb ) Operation - Yaesu FT-991 Operating Manual

The FT-991 includes an effective IF Noise Blanker, which can significantly reduce noise caused by automotive ignition
systems.
1. Touch [ NB ] displayed by pressing the F(M-LIST)
button briefly to reduce short duration pulse noise
such as from switching transients, automobile igni-
tions and power lines. The "NB ON" will appear in
the display to confirm that the Narrow-NB is operat-
ing.
2. Touch [ NB ] on the LCD again to reduce longer-
duration man-made pulse noise. The "NBW ON"
will appear in the display to confirm that the Wide-
NB is operating.
3. If desired, you may adjust the Noise Blanker level
via Menu item "024 NB LEVEL" to the point where
the offending noise is best reduced or eliminated.
See box below for details.
4. To end Noise Blanker operation, touch [ NB ] on the
LCD once more. The "NB OFF" will appear in the
display, confirming that the Noise Blanker is no lon-
ger in operation.
1. Press the MENU button to engage the Menu
mode.
2. Rotate the MULTI knob to select Menu item "024
NB LEVEL".
3. Touch [ SELECT ] on the LCD
4. Rotate the MULTI knob to the point where the
offending noise is best reduced or eliminated.
5. Touch [ ENTER ] on the LCD, then press the
MENU button or touch [ BACK ] on the LCD to
lock in the new setting and exit to normal opera-
tion.
FT-991 O
peraTing
i
nTerferenCe
iF n b
oiSe lAnker
Adjusting the Noise Blanker Level
M
anual
( nb ) o
perAtion
F(M-LIST) Button
MENU button
MULTI Knob
r
eJeCTion
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