Contour; (Interference Rejection "Signals Within 3 Khz") - Yaesu FT-450D Operation Manual

C
ONVENIENCE
CONTOUR ( I
The Contour filtering system provides a gentle perturbation of the DSP 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.
1. Press the [ DSP ] button several times to set the
" " icon to the "
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".
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 "
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
" " indicator of the LCD Display, confirm-
ing that the contour filter is no longer operating.
C "N "
ONTOUR ULL
C "P "
ONTOUR EAK
C "O "
ONTOUR FF
C
ONTOUR
C "N "
ONTOUR ULL
C "P "
ONTOUR EAK
C "O "
ONTOUR FF
C
ONTOUR
Q P :
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.
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F
EATURES
NTERFERENCE
" indicator of the DSP
" indicator of the
G "L "
AIN OW
G "H "
AIN IGH
R
EJECTION "S
IGNALS WITHIN
"CONTOUR" Indicator
[ DSP/SEL ] knob
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.
A
FT-450D O
)
3 "
KHZ
[ DSP ] button
B C
M
PERATION ANUAL