Yaesu FTDX101MP Operation Manual page 53

Outer Knob (WIDTH)
The IF WIDTH tuning system allows you to vary the
width of the DSP IF passband, to reduce or elimi-
nate interference.
Moreover, the bandwidth may actually be expanded
from its default setting, should you wish to enhance
incoming signal fidelity when interference on the
band is low.
Rotate the [WIDTH] knob counter-clockwise to nar-
row the bandwidth and reduce interference.
● To increase the bandwidth, rotate the knob clock-
wise.
● Rotate the [WIDTH] knob, the IF filter bandwidth
is displayed on the display.
● Press and hold the [SHIFT] knob to return the
bandwidth of the IF filter to its initial value (see
below).
● On the filter function display area, you can check
the status of the bandwidth.
● While the WIDTH function is active, the indicator
on the right side of the [WIDTH] knob will light.
WIDTH and SHIFT can be adjusted alter-
nately, while listening for the best reception
point.
CONTOUR and NOTCH may be used to-
gether to effectively eliminate inter- ference
and increase intelligibility
The IF SHIFT and Variable IF WIDTH features together form a very effective interference-fighting fil-
tering system.
For example, in Figure "A", you can see how in-
terference 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 inter-
ference on the opposite side can be removed, without
re-introducing the interference previously eliminated in
Figure "B".
For best interference reduction, the WIDTH and SHIFT features are the primary tools you should use, after nar-
rowing 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.
48
Using IF SHIFT and WIDTH Together
Referring to Figure "B", you can see the default
bandwidth of the SSB mode.
By rotating the [SHIFT] knob to the left, the
bandwidth will narrow (see Figure "A"), while
rotation of the [SHIFT] knob to the right, will
increase the bandwidth as depicted in Figure "C".
The default bandwidths, and total bandwidth
adjustment range, will vary according to the
operating mode (see table below).
A B
IF BANDWIDTH IF BANDWIDTH
WIDTH knob WIDTH knob
Operating Mode
SSB (LSB/USB)
CW (CW-L/CW-U),
RTTY, PSK
DATA (LSB/USB)
AM, FM-N, D-FM-N
AM-N
FM, DATA-FM
A B
Desired Signal Desired Signal
QRM
QRM QRM
IF BANDWIDTH IF BANDWIDTH
C
IF BANDWIDTH
WIDTH knob
IF BANDWIDTH
300 Hz - 4000 Hz
(default: 3000 Hz)
50 Hz - 3000 Hz
(default: 500 Hz)
9000 Hz
6000 Hz
16000 Hz
C
Desired Signal
QRM
QRM
QRM
IF BANDWIDTH