Width (If Dsp Bandwidth) Tuning; Using If Shift And Width Together - Yaesu FT DX 3000 Operating Manual

i
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. Rotate the [ WIDTH ] knob to the left or right to re-
duce the interference.
A :
dvice
The frequency display will show the bandwidth of
the IF passband for 3 seconds whenever the [ WIDTH ]
knob is turned.
A :
dvice
The IF Bandwidth will be memorized independently on
each VFO stack of VFO-A and VFO-B.
Referring to Figure "B", you can see the default
bandwidth on the SSB mode.
By rotating the [ WIDTH ] knob to the left, the
bandwidth will narrow (see Figure "A", while
rotation of the [ WIDTH ] knob to the right, as
depicted in Figure "C", will increase the band-
width.
A
IF BANDWIDTH IF BANDWIDTH
SHIFT SHIFT
The default bandwidths, and total bandwidth ad-
justment range, will vary according to the operat-
ing mode:
SSB Mode: 1.8 kHz ~ 4.0 kHz (default: 2.4 kHz).
CW Mode: 500 Hz ~ 2.4 kHz (default: 2.4 kHz)
RTTY/DATA Modes: 500 Hz ~ 2.4 kHz (default:
500 Hz)
Page 54
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ejecTiOn
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ANdwidtH
B C
IF BANDWIDTH
SHIFT
( SSb/cw/Rtty/pKt M
uNiNg
[ WIDTH ] Knob
widtH i
Using IF SHIFT and WIDTH Together
The IF SHIFT and Variable IF WIDTH features
together form a very effective interference-fight-
ing filtering system.
For example, in Figure "A", you can see how
interference has appeared both on the high
and low sides of the desired signal. Rotate the
[ WIDTH ] knob, the interference from one side
can be eliminated (Figure "B"). Next, rotate the
[ SHIFT ] knob to re-position the passband (Figure
"C"), the interference on the opposite side can be
removed, without re-introducing the interference
previously eliminated in Figure "B".
A
Desired Signal
QRM
QRM
IF BANDWIDTH
A :
dvice
For best interference reduction, the WIDTH and
SHIFT features are the primary tools you should
use, after narrowing the bandwidth (WIDTH)
and/or adjusting the center of the passband
(SHIFT). The Contour control may then yield
additional signal-enhancement benefits on
the net residual bandwidth. Even more, the IF
NOTCH Filter (described later) may also be
used, in conjunction with these filter systems, to
significant advantage.
FT
DX
odeS
NdicAtoR
B C
Desired Signal Desired Signal
QRM
QRM QRM
IF BANDWIDTH IF BANDWIDTH
3000 O M
peraTing
)
QRM
anual