4-5
BASIC MANUAL
RECEIVING AND TRANSMITTING
4
4
Using the
Digital Twin PBT
SSB, CW, RTTY, and AM modes
To reject interference, the Digital Twin Passband
Tuning (PBT) narrows the IF passband width by
electronically shifting the IF frequency to slightly
above or below the IF center frequency. The IC-905
uses the digital function using the FPGA (Field
Programmable Gate Array) filtering method.
L
Each mode memorizes the PBT setting.
1. Push
to select “PBT1.”
L
Each push selects “PBT1” or “PBT2.”
L
Information
•
A dot “·” is displayed on the IF Filter Indicator when you
change the IF passband width, using the Digital Twin
PBT.
•
Touch the filter icon for 1 second to display the current
passband width and shift value.
Opens the FILTER screen.
2. Rotate
to adjust the shift value.
•
The passband width and shift value are displayed.
•
Hold down
for 1 second to clear the PBT
setting.
3. Repeat steps 1 and 2 to adjust the shift value for
“PBT2.”
L
Information
•
To narrow the IF passband width, shift “PBT1” and “PBT2”
to the opposite direction from each other, to narrow the
overlapped area.
•
To use as the IF Shift function, set “PBT1” and “PBT2” to
the same value.
•
The PBT is adjustable in 50 Hz steps in the SSB, CW,
and RTTY modes, and 200 Hz in the AM mode. The
center shift value changes in 25 Hz steps in the SSB,
CW, and RTTY modes, and 100 Hz in the AM mode.
NOTE:
While rotating
, you may hear some
noise. This comes from the FPGA and does not
indicate an equipment malfunction.
“1” (PBT1) or
“2” (PBT2)
Passband width
Shift value
PBT1
PBT2
PBT1
PBT2
PBT1
PBT2
PBT1
PBT2
SFT: Shift value
Passband center
frequency
IF center frequency
BW: Passband
width
IF center frequency
Default value
Cutting
lower passband
Cutting both higher and
lower passbands
Interference
Interference
Interference
Passband
Passband
Desired
signal
Desired
signal
Содержание IC-905
Страница 1: ...BASIC MANUAL ALL MODE TRANSCEIVER 905...
