Yaesu FT-450D Manuale Utente
Page 28
FT-450D O
PERATION
M
ANUAL
IF
BANDWIDTH
IF
BANDWIDTH
IF
BANDWIDTH
CONTOUR (I
NTERFERENCE
R
EJECTION “S
IGNALS
WITHIN
3
KHZ
”
)
The Contour filtering system provides a gentle perturbation of the IF filter pass band, so as to suppress or
enhance particular frequency components in five steps, thus improving the sound and/or readability of a re-
ceived signal.
enhance particular frequency components in five steps, thus improving the sound and/or readability of a re-
ceived signal.
1. Press the [DSP] button several times to set the
“>” icon to the “CONTOUR” indicator of the DSP
Graphic Display on the display.
Graphic Display on the display.
2. Press the [DSP/SEL] knob to engage the con-
tour filter.
3. Press and hold the [DSP/SEL] knob for one sec-
ond to toggle the contour filter’s level between
“null” and “peak”.
“null” and “peak”.
4. Rotate the [DSP/SEL] knob to achieve the most
natural-sounding audio reproduction on the in-
coming signal.
The peak position of the contour filter is graphi-
cally-depicted in the “CONTOUR” indicator of the
DSP Graphic Display on the LCD.
coming signal.
The peak position of the contour filter is graphi-
cally-depicted in the “CONTOUR” indicator of the
DSP Graphic Display on the LCD.
5. Press the [DSP/SEL] knob again to increase the
contour filter’s level (“null” or “peak”).
6. To disable the contour filter, press the [DSP/SEL]
button again. The graphic disappears from the
“CONTOUR” indicator of the LCD Display, confirm-
ing that the contour filter is no longer operating.
“CONTOUR” indicator of the LCD Display, confirm-
ing that the contour filter is no longer operating.
Q
UICK
P
OINT
:
The steep slopes of the DSP filtering can, when adjusted aggressively, impart an unnatural sound to an incom-
ing signal. Often, a narrow bandwidth is not the key to improving copy. The incoming signal itself may have
undesirable or excessive frequency components. By judicious use of the Contour filter, the “shoulder” of the
passband response may be altered, or components removed from within the passband, allowing the desired
signal to rise above the background noise and interference in a manner not obtainable with other filtering sys-
tems.
ing signal. Often, a narrow bandwidth is not the key to improving copy. The incoming signal itself may have
undesirable or excessive frequency components. By judicious use of the Contour filter, the “shoulder” of the
passband response may be altered, or components removed from within the passband, allowing the desired
signal to rise above the background noise and interference in a manner not obtainable with other filtering sys-
tems.
C
ONVENIENCE
F
EATURES
“CONTOUR” Indicator
[DSP] button
[DSP/SEL] knob
C
ONTOUR
G
AIN
“H
IGH
”
C
ONTOUR
“N
ULL
”
C
ONTOUR
“P
EAK
”
C
ONTOUR
“O
FF
”
C
ONTOUR
G
AIN
“L
OW
”
C
ONTOUR
“N
ULL
”
C
ONTOUR
“P
EAK
”
C
ONTOUR
“O
FF
”
Refer to Figure “B”, this shows a “indenta-
tion” of the contour filter is center of a pass-
band. Counter-clockwise rotation (to the left)
of the [DSP/SEL] knob causes the indenta-
tion to move toward a lower frequency within
the passband, while clockwise rotation (to the
right) causes the indentation to move toward
a higher frequency within the passband. By
removing interference or unwanted frequency
components on the incoming signal, it is pos-
sible to make the desired signal rise out of
the background noise/interference, enhanc-
ing intelligibility.
tion” of the contour filter is center of a pass-
band. Counter-clockwise rotation (to the left)
of the [DSP/SEL] knob causes the indenta-
tion to move toward a lower frequency within
the passband, while clockwise rotation (to the
right) causes the indentation to move toward
a higher frequency within the passband. By
removing interference or unwanted frequency
components on the incoming signal, it is pos-
sible to make the desired signal rise out of
the background noise/interference, enhanc-
ing intelligibility.
A B C