Yaesu FT DX 9000MP CONTEST - DATA MANAGEMENT..., Руководство по эксплуатации

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Page 74 FT
DX
9000MP O
PERATION
M
ANUAL
For example, in Figure (A) you can see how interfer-
ence has appeared both on the high and low sides of
the desired signal. By rotating the [
WIDTH
] control,
as shown in Figure (B), the interference from one side
can be eliminated, and by re-positioning the [
SHIFT
]
control (Figure (C)), the interference on the opposite
side can be removed, without re-introducing the inter-
ference previously eliminated in Figure (B).
A A A A A
D D
D D
DVICE VICE
VICE VICE
VICE
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
also yield additional signal-enhancement benefits on
the net residual bandwidth. What’s more, the IF Notch
Filter (see the next section) may also be utilized, in
conjunection with the three other filter systems, to sig-
nificant advantage.
Using IF Shift and Width Together
The IF Shift and Variable IF Width featuress together form a very effective interference-fighting filtering system.
QRM
QRM
QRM
QRM
QRM
QRM
Desired Signal
IF BANDWIDTH IF BANDWIDTH IF BANDWIDTH
B
C
A
IIIII
NTERFERENCE NTERFERENCE
NTERFERENCE NTERFERENCE NTERFERENCE
R R R R R
EJECTION EJECTION
EJECTION EJECTION EJECTION
(S(S(S(S(S
IGN IGN
IGN IGN
IGNALS ALS
ALS ALS
ALS WITHIN WITHIN
WITHIN WITHIN
WITHIN
3 3
3 3
3
KHZ KHZ
KHZ KHZ
KHZ
)))))
WIDTH
(
IF DSP B
ANDWIDTH
)
T
UNING
(
SSB/CW/RTTY/PKT M
ODES
)