Icom IC-756PROIII Instruction Manual page 11

@9 ∂ ∂ TX SWITCH [∂ ∂ TX] (p. 69)
➥ Turns the ∂TX function ON and OFF when
pushed.
• Use the [RIT/∂ ∂ TX] control to vary the ∂TX frequency.
➥ Adds the ∂TX shift frequency to the operating
frequency when pushed for 1 sec.
✔ What is the ∂ ∂ TX function?
The ∂TX shifts the transmit frequency without shifting the re-
ceive frequency. This is useful for simple split frequency op-
eration in CW, etc.
#0 CLEAR SWITCH [CLEAR] (pgs. 58, 69)
Clears the RIT/∂TX shift frequency when pushed
for 1 sec. (default).
• The response time (for 1 sec. or momentarily) can be
selected on the quick RIT/∂TX clear setting (p. 103).
#1 RIT SWITCH [RIT] (p. 58)
➥ Turns the RIT function ON and OFF when
pushed.
• Use the [RIT/∂ ∂ TX] control to vary the RIT frequency.
➥ Adds the RIT shift frequency to the operating fre-
quency when pushed for 1 sec.
✔ What is the RIT function?
The RIT (Receiver Incremental Tuning) shifts the receive fre-
quency without shifting the transmit frequency.
This is useful for fine tuning stations calling you on an off-fre-
quency or when you prefer to listen to slightly different-
sounding voice characteristics, etc.
#2 MANUAL NOTCH FILTER CONTROL [NOTCH]
(inner control; p. 64)
Varies the peak frequency of the manual notch fil-
ter to pick out a receive signal from interference
while the manual notch function is ON.
• Notch filter center frequency:
SSB : 0 Hz to 5100 Hz
CW : CW pitch freq.–900 Hz to CW pitch freq.
+4200 Hz
AM : –5100 Hz to 5100 Hz
NOTCH
Lower frequency
#3 CW PITCH CONTROL [CW PITCH]
(outer control; p. 37)
Shifts the received CW audio pitch and monitored
CW audio pitch without changing the operating fre-
quency.
NOTCH
Lower frequency
Approx. 300 Hz
CW PITCH
Higher frequency
CW PITCH
Higher frequency
Approx. 900 Hz
PANEL DESCRIPTION
#4 NOTCH SWITCH [NOTCH] (p. 64)
➥ Switches the notch function between auto, man-
ual and OFF in SSB and AM modes.
➥ Turns the manual notch function ON and OFF
when pushed in CW mode.
➥ Turns the auto notch function ON and OFF when
pushed in FM mode.
• "AN" appears on the display when auto notch is in
use.
• "MN" appears on the display when manual notch is in
use.
• The [NOTCH] indicator in this switch lights green
when the function is activated.
NOTCH
Notch OFF
✔ What is the notch function?
The notch function eliminates unwanted CW or AM carrier
tones while preserving the desired signal's audio response.
The filtering frequency is adjusted to effectively eliminate un-
wanted tones via the DSP circuit.
#5 PBT CLEAR SWITCH [PBT CLR] (p. 60)
Clears the PBT settings when pushed for 1 sec.
• The [PBT CLR] indicator in this switch lights green when
PBT is in use.
#6 PASSBAND TUNING CONTROLS [TWIN PBT]
Adjust the receiver's "passband width" of the DSP
filter. (p. 60)
• Passband width and shift frequency are displayed in the
LCD.
• Push [PBT CLR] for 1 sec. to clear the settings when
not in use.
• Variable range is set to half of the IF filter passband
width. 25 Hz steps and 50 Hz steps are available.
• These controls function as an IF shift control while in AM
mode and when the RTTY filter is turned ON. Only the
inner control may function in this case.
✔ What is the PBT control?
General PBT function electronically narrows the IF passband
width to reject interference. This transceiver uses the DSP
circuit for the PBT function.
TWIN PBT
TWIN PBT TWIN PBT
–
Low cut Center
1
NOTCH
Notch ON
PBT1
PBT2
TWIN PBT
+
High cut
1
6