Yaesu FT-991 User Manual

Page 50 FT-991 OperaTing Manual
Width
(
iF dSp bAndWidth
)
tuning
(
SSb/cW/rtty/dAtA ModeS
)
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delity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.
MULTI Knob
F(M-LIST) Button
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
A B C
IF BANDWIDTH IF BANDWIDTH IF BANDWIDTH
MULTI MULTI MULTI
Advice:

Toincreasethebandwidth,rotatetheknobclock-
wise.

 Rotatethe
MULTI
knobtodisplaythebandwidth
oftheIFlterbelowthe
[
WIDTH
]
indicator(Re-
fertotheinstructionbelow).

For reference, the level indicator on the TFT dis-
playshowsthebandwidth.
interference reJection

Yaesu FT-991 Specifications

General

Brand	Yaesu
Model	FT-991
Category	Transceiver
Language	English