Twin Pbt Operation - Icom IC-7000 Instruction Manual

5
FUNCTIONS FOR RECEIVE

■ Twin PBT operation

General PBT (Passband Tuning) function electronically
narrows the IF passband width by shifting the IF fre-
quency to slightly outside of the IF filter passband to
reject interference. This transceiver uses the DSP cir-
cuit for the PBT function. Moving both [PBT
controls to the same position shifts the IF.
➥ Push [PBT/M-ch/RIT] momentarily to select the
twin PBT function, if the M-ch-RIT is selected.
• [PBT/M-ch/RIT] indicator (Green) lights.
• The passband settings window shows the passband
width and shift frequency graphically. (The passband
settings window can be turned OFF in the display set
mode. p. 127)
➥ When M-1 is selected, push [F-3 FIL] for 1 sec. to
enter the filter set mode. Current passband width
and shift frequency is displayed in the filter set
mode.
➥ To set the [PBT
/M-ch/RIT
tions, push [PBT
/M-ch/RIT
The limit of the variable range depends on the pass-
band width and mode. The edge of the variable range
is half of the passband width, and PBT is adjustable in
100 (AM) or 25 Hz steps (other modes).
PBT OPERATION EXAMPLE
Both controls at
center position
IF center frequency
79
/M-ch/RIT
] controls to the center posi-
( )] for 1 sec.
CLR
Cutting a lower
passband
Interference Desired signal
[PBT (CLR)] switch/[PBT] (inner) control
/M-ch/RIT
[PBT/M-ch/RIT] indicator
]
[PBT] (outer) control
Dot indicator appears
when PBT is activate
Passband
width
Shift
frequency
• [PBT] controls should normally be set to the center posi-
tions (PBT setting is cleared) when there is no interfer-
ence.
• When PBT is used, the audio tone may be changed.
• Not available for FM or WFM modes.
• While rotating [PBT], noise may occur. This comes from
the DSP unit and does not indicate an equipment mal-
function.
Passband
Interference
[F-3]
[MENU/GRP]
Selected IF filter
Popup indicator appears
Cutting both higher and
lower passbands
Passband
Interference
Desired signal