Adjusting The Twin Pbt Operation - Icom IC-7200 Advanced Instructions

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5
FUNCTIONS FOR RECEIVE

■ Adjusting the Twin PBT operation

The Twin PBT (Passband Tuning) function electroni-
cally narrows the IF passband width by shifting the IF
frequency slightly outside of the IF filter passband to
reject interference. This transceiver uses the DSP cir-
cuit for the PBT function.
By rotating both [TWIN PBT] controls (inner/outer;
PBT1 and PBT2) with the same position, PBT func-
tions as an IF shift control.
The limit of the variable range depends on the pass-
band width and mode. The limit of the variable range
is half of the passband width, and PBT is adjustable in
200 Hz (AM) or 50 Hz (other models) steps.
• The [TWIN PBT] controls should normally be set
to the center positions (PBT shift is zero) when
there is no interference.
• When PBT is used, the audio tone may change.
• While rotating the [TWIN PBT] controls, noise may
occur. This comes from the DSP unit and does not
indicate an equipment malfunction.
PBT OPERATION EXAMPLE
Both controls at
center position
TWIN PBT
IF center frequency
Cutting the lower
passband
TWIN PBT
Passband
Interference Desired signal
5-4
[TWIN PBT]
Cutting both higher and
lower passbands
TWIN PBT
Interference
Desired signal
Passband
Interference