Icom IC-756 - Manual (Page 28)

■ Twin PBT operation
The twin PBT (Passband Tuning) function electronically
narrows the receiver’s IF passband widths to reduce
interference. Moving both [TWIN PBT] controls to the
same position shifts the IF.
- The LCD shows the passband width graphically.
Variable range depends on the filter selection. ± 1.29
kHz in 15 Hz steps and ± 258 kHz in 3 Hz steps are
available.
• [TWIN PBT] should normally be set to the center
positions when there is no interference.
• When PBT is used, the audio tone may be
changed.
• PBT may not function with some IF filter combina-
tions.
• Not available for FM mode.
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4
RECEIVE AND TRANSMIT
■ Mode selection
The following modes are available in the IC-756:
SSB (LSB/USB), CW, CW-R (CW reverse), RTTY,
RTTY-R (RTTY reverse), AM, FM and FM-T (FM with
subaudible tone). Narrow modes of each of these are
also available.
To select a mode of operation, push the desired mode
switch momentarily. Push the switch again to toggle
between normal and narrow mode. Push the switch
for 2 sec. to toggle between USB and LSB, CW and
CW-R, RTTY and RTTY-R, FM and FM-T, if neces-
sary.
See the diagram at right for the order of selection.
USB LSB
CW CW-R
RTTY RTTY-R
AM
Push mode switch
for 2 sec. Push mode switch
momentarily.
FM FM-T
USB-N LSB-N
CW-N CW-RN
RTTY-N RTTY-RN
AM-N
FM-N FM-TN
SSB
CW
RTTY
AM
FM
PBT OPERATION EXAMPLE
TWIN PBT TWIN PBT TWIN PBT
IF center frequency Interference Desired signal
Passband
Both controls at
center position Cutting a lower
passband Cutting both higher and
lower passbands
Interference Interference
Desired signal
Passband