Width (If Dsp Bandwidth) Tuning - Yaesu FT-991 Operating Manual

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nterference
Width ( iF dSp b
The IF WIDTH tuning system allows you to vary the width of the DSP IF passband, to reduce or eliminate interference.
Moreover, the bandwidth may actually be expanded from its default setting, should you wish to enhance incoming sig-
nal fidelity when interference on the band is low.
1. Press the F(M-LIST) button to display the function
menu list. Touch the [ WIDTH ] icon to activate this
function and cause the MULTI knob to function as
the WIDTH adjustment knob.
WIDTH indicator
WIDTH level indicator
2. Rotate the MULTI knob counter-clockwise to narrow
the bandwidth and reduce interference.
Referring to Figure "B", you can see the default
bandwidth of the SSB mode.
By rotating the MULTI knob to the left, the band-
width will narrow (see Figure "A"), while rota-
tion of the MULTI knob to the right, will increase
the bandwidth as depicted in Figure "C".
The default bandwidths, and total bandwidth ad-
justment range, will vary according to the operat-
ing mode:
SSB Mode: 1.8 kHz - 3.2 kHz (default: 2.4 kHz).
CW Mode: 500 Hz - 3 kHz (default: 2.4 kHz)
RTTY/DATA (LSB, USB) Modes: 500 Hz - 3
kHz (default: 500 Hz)
AM Mode: Fixed at 9 kHz
FM/DATA-FM/C4FM Modes: Fixed at 16 kHz
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r
eJection
) t
AndWidth uning
( SSb/cW/rtty/dAtA M
F(M-LIST) Button
MULTI Knob
A :
dvice
 To increase the bandwidth, rotate the knob clock-
wise.
 Rotate the MULTI knob to display the bandwidth
of the IF filter below the [ WIDTH ] indicator (Re-
fer to the instruction below).
 For reference, the level indicator on the TFT dis-
play shows the bandwidth.
A B
IF BANDWIDTH IF BANDWIDTH
MULTI MULTI
FT-991 O
)
odeS
C
IF BANDWIDTH
MULTI
M
peraTing anual