Kenwood TS-990S - Manual (Page 150)

6 REJECTING INTERFERENCE
6-12
Index Contents
BAND ELIMINATION FILTER
Band Elimination Filter is the notch filter that can change
the bandwidth and attenuation at the IF stage.
The stopband width can be selected from the available
range of 300 Hz to 1200 Hz (in steps of 100 Hz) and the
amount of attenuation can be selected from the available
range of 20 dB to 80 dB (in steps of 20 dB).
If there are two or more interfering signals, you can adjust
the stopband width and attenuation level according to the
strength of the interfering signals, thus making the target
signal clear.
Interfering Signal
Width
Attenuation Target Signal
[F1] [F7]
[ESC] [NOTCH] (S)
[MULTI/CH]
[NOTCH] (M)
[BEF/SEL] (M)
[BEF/SEL] (S)
■ Activating or deactivating the Band Elimination
Filter.
1 Press [BEF/SEL] (M) or [BEF/SEL] (S) to enable the
band elimination filter for the selected band.
• The "BEF/SEL" (M) LED or "BEF/SEL" (S) LED lights
green. In the main screen, "BEF" will appear above the
frequency display of the selected band.
• The letter "Y" appears to indicate the notch frequency if the
filter type is displayed in the sub screen.
• Press the key again to disable the band elimination filter for
the selected band.
2 Rotate the NOTCH (M) or NOTCH (S) control to adjust
the notch filter frequency.
You can adjust the notch frequency to the point where the
beat or interference is suppressed. The letter "Y" indicating
the notch frequency moves left and right if the filter type
appears on the sub-screen.
Note:
◆ The band elimination filter is deactivated if the manual notch filter
or band elimination filter is active.
◆ The notch point against an interfering beat cannot be changed
even if a pitch and shift is changed after the notch point is
determined in CW mode.
■ Changing the stopband width 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 select "Wide"
for the bandwidth.
3 Press [-] (F4) or [+] (F5), or rotate the MULTI/CH
control to select the stopband width.
• You can select the stopband width of the band elimination
filter.
• Available range is "300" Hz to "1200" Hz (in steps of 100
Hz).
• The default is "400".
4 Press [ESC] to exit.
Pressing and holding [BEF/SEL] (M) or [BEF/SEL] (S)
closes the Band Elimination Filter screen.