Dsp Cw Peaking Filter (Dbf); Dsp Noise Reduction (Dnr) - Yaesu FT-857D Operating Manual

R
ECEIVER
DSP CW P
EAKING
In the CW mode, pressing the [ C ]( DBF ) key in Multi Function Row "p" [ DNR, DNF, DBF ]
activates a narrow-bandwidth peaking filter, which may be ideal for use under very crowded
conditions. The DSP CW Peaking Filter also is especially helpful under VHF/UHF weak-
signal situations.
The center frequency of the DSP CW Peaking Filter is automatically aligned to be centered
on the response you have selected via the Menu Mode in item No-027 [ CW PITCH ] . See
page 101 for details.
1. To change the bandwidth of the DSP CW Peaking Filter:
2. Press and hold in the [ C ]( DBF ) key for one second on the CW mode. This instantly
activates Menu Mode No-045 [ DSP BPF WIDTH ] , which allows selection of the band-
width of the DSP CW Peaking Filter.
3. Rotate the DIAL to select the desired bandwidth. The available values are 60 Hz, 120
Hz, and 240 Hz (default value: 240 Hz).
4. When you have made your selection, press and hold in the [ FUNC ] key for one second
to save the new setting and return to normal operation.
DSP N
OISE
The Noise Reduction feature of the DSP system may be used to enhance signal-to-noise
ratio on weak signals.
1. Press the [ DSP ] key momentarily. This instantly activates Multi Function Row "p" [ DNR,
DNF, DBF ] .
2. Press the [ A ]( DNR ) key to activate the DSP Noise Reduction feature. The "u" icon will
appear at the left side of the "DNR" indication, and the "
the top on the display.
3. Now press and hold in the [ A ]( DNR ) key for one second. This instantly activates Menu
Mode No-049 [ DSP NR LEVEL ] , which allows adjustment of the DSP Noise Reduction
level.
4. Rotate the DIAL to find the point where best signal-to-noise ratio is obtained under the
current noise conditions.
5. Press and hold in the [ FUNC ] key for one second to save the new setting and exit to
normal operation.
6. To turn off the DSP Noise Reduction feature, press the [ A ]( DNR ) key again.
If noise is present at a level which causes indication on the S-meter, the perfor-
mance of the Noise Reduction filter may be enhanced by rotating the SQL/RF
(RF Gain) control in a counter-clockwise direction so as to set the (fixed) S-meter read-
ing at the same level as the noise peaks. This adjustment raises the AGC threshold of the
receiver.
44
A
CCESSORIES
F
ILTER
( DNR )
R
EDUCTION
( DBF )
( R
EQUIRES
( R
EQUIRES
FT-857 Operating Manual
O DSP-2 U
PTIONAL
O DSP-2 U
PTIONAL
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