Yaesu FTdx5000MP, Руководство по эксплуатации

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Page 62 FT
DX
5000 O
PERATING
M
ANUAL
I
NTERFERENCE
R
EJECTION
(
S
IGNALS WITHIN
3
KHZ
)
U
SING
IF S
HIFT AND
W
IDTH
T
OGETHER
(
SSB/CW/RTTY/PKT/AM M
ODES
)
The IF Shift and Variable IF Width features, together, form a very effective interference-fighting filter system.
IF
BANDWIDTH
IF
BANDWIDTH
IF
BANDWIDTH
Desired Signal Desired Signal Desired Signal
QRM
QRM QRM QRM
QRM QRM
For example, in Figure “ A ” you can see how interference
has appeared both on the high and low sides of the desired
signal. By pressing the [
WIDTH
] button (the button will
glow red) and then rotating the [ SELECT
](width) knob,
as shown in Figure “ B ”, the interference from one side
can be eliminated, then press the [ SHIFT
] button to change
the function of the [ SELECT
] knob to the SHIFT knob
(the [
SHIFT
] button glows red. However, the IF Width
adjustment is not changed). Now, by re-positioning the
[
SELECT
](shift) knob (Figure “
C ”), the interference on
the opposite side can be removed, without re-introducing
the interference previously eliminated in Figure “
B ”.
A
DVICE
:
The Width and Shift features are the primary tools you
should use for best interference reduction. After narrow-
ing the bandwidth (width) and/or adjusting the center of
the passband (shift), the Contour control may also yield
further signal-enhancement benefits on the net residual
bandwidth. Additionally, the IF Notch Filter (see the next
section) may be utilized, in conjunction with the three other
filter systems, to significant advantage.
A B C