Twin Pbt Operation - Icom IC-7100 Instruction Manual

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5
FUNCTIONS FOR RECEIVE

Twin PBT operation

(Mode: SSB/CW/RTTY/AM)
To reject interference, PBT (Passband Tuning) electron-
ically narrows the IF passband width by shifting the IF
frequency slightly outside of the IF fi lter passband. The
IC-7100 uses DSP for the PBT function. Moving both
TWIN-PBT ([M-CH/BANK]
passband center frequency both above and below the
received frequency.
➥
The LCD graphically shows the passband width and
frequency shift.
➥
Touch the Filter icon for 1 second to display the "FIL-
TER" screen. The current passband width and fre-
quency shift are displayed.
➥
Hold down [CLR] (L) for 1 second to set the IF
frequency to the center position.
• The "dots" disappear.
The PBT is adjustable in 50 Hz steps in the SSB/CW/
RTTY modes, and 200 Hz in the AM mode.
When adjusting, the shift value changes in 25 Hz steps
in the SSB/CW/RTTY modes, and 100 Hz in the AM
mode.
• The TWIN-PBT controls should normally be set to
the center positions when there is no interference.
The PBT setting should be cleared.
• When the PBT is used, the audio tone may
change.
• The controls do not function in the FM, WFM and
DV modes.
• While rotating the TWIN-PBT ([M-CH/BANK]
controls, noise may occur. This comes from the
DSP unit and does not indicate an equipment mal-
function.
• Pushing [M-CH]] (L) displays the fi lter passband
width and shift value for 1 second.
PBT OPERATION EXAMPLE
Both controls in the
center positions
PBT2
IF center frequency
(L)) controls shifts the IF
(L))
Cutting the lower
passband edge
PBT1
Interference Desired signal
Passband width and shift value are dis-
played while the TWIN PBT is used.
• "FILTER" screen display
Shows the selected fi lter and passband width.
• While adjusting the PBT setting
A dot appears when the passband is shifted.
• About Passband width and Shift value
on the screen
BW
IF center
SFT
frequency
Cutting both lower and
higher passband edges
PBT2
PBT1
Passband
Interference
5-5
Appear when pass-
band is shifted.
: Passband width
( Width of („) in which
the two PBTs overlap)
Passband's
center frequency
: Shift value
PBT2
PBT1
Passband
Desired signal Interference