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.
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
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.
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.
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.
R
ECEIVER
A
CCESSORIES