Vertex Standard FT-857 Benutzerhandbuch
44
FT-857 Operating Manual
DSP CW P
EAKING
F
ILTER
(DBF)
(R
EQUIRES
O
PTIONAL
DSP-2 U
NIT
)
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.
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.
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
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.
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
R
EDUCTION
(DNR)
(R
EQUIRES
O
PTIONAL
DSP-2 U
NIT
)
The Noise Reduction feature of the DSP system may be used to enhance signal-to-noise
ratio on weak signals.
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 “
” notation will appear at
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.
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
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.
ing at the same level as the noise peaks. This adjustment raises the AGC threshold of the
receiver.
R
ECEIVER
A
CCESSORIES