15
SKY-SDR USER MANUAL Ver. 1.3.1 - 28-MAR-2017
There is only one filter for
DIGI mode
with a fixed bandwidth of 3.35 kHz.
On
all other modes
, F1, F2 & F3 are
fixed bandwidths and are not user
adjustable. F4 is user-adjustable to
any convenient bandwidth and may be
adjusted without exiting Operating
Mode.
The bandwidth of the selected filter is
shown in kHz on the display, preceded
by the filter number. Example:
“F1: 2.9 kHz” or “F4: 0.1 kHz”.
In
CW and SSB modes
you can also
change the passband center frequency
as well as the bandwidth. This is not
necessary in AM or FM.
In
CW mode
, this is accomplished by
setting “CW PITCH” in
Menu Mode
item #2
. The bandwidth of the filter
selected is then centered on that
frequency.
In
SSB mode
(LSB or USB), this is
accomplished by setting the Lo-Cut and
Hi-Cut frequencies; the bandwidth is
then the difference between these two
frequency, the passband center is the
determined by the Hi-Cut frequency
minus half of the passband bandwidth.
Example follows below.
F4 Filter Adjustment:
For
AM/FM & CW
, filter adjustment is
simple. While in operate mode:
•
Select the filter F4.
•
Press
[F]
(blue button)
•
Press
[Filter]
(the current
bandwidth appears)
•
Rotate the VFO knob to adjust
the
bandwidth
(CW=wider,
CCW=narrower). Changes are
heard in real-time, but not yet
saved.
•
Once the desired bandwidth is
set, save the change by pressing
the “Filter” button again.
EXAMPLE-1:
Say we want a 100 Hz
CW filter
centered on 650 Hz:
•
Select CW Mode
•
Select filter “F4”
•
Press
[F]
, then press
[Filter]
•
Using the VFO knob, set the
bandwidth to 100.
•
Set the center frequency of the
passband for the CW filter in
Menu Mode item #2
(CW
Pitch).
Push “MENU”, the
n using the UP
or DOWN arrows, scroll to
Item
#2 (CW Pitch).
Adjust the VFO
knob to 650. Press [MENU] to
exit and save settings.
The
SSB F4
filter’s bandwidth and
passband are also easy to adjust.
The filter is adjusted by re-defining the
“Low Cutoff Frequency” and “High
Cutoff Frequency” of the filter’s
passband. The parameters are set as
follows:
•
Bandwidth: difference between
the two frequencies (Hi Freq.
–
Lo Freq.).
•
Passband Center: Hi Freq.
minus half the bandwidth
frequency.
EXAMPLE-2:
Say we want an SSB
filter 1.8 kHz wide, centered on 1.5
kHz:
•
Select USB Mode
