Icom IC-7760 Advanced Manual page 44

2
ADVANCED OPERATIONS
DPD function
SSB and AM modes
The Digital Pre-Distortion (DPD) function reduces
the distortion of the SSB, SSB-D, AM, or AM-D mode
signals transmitted by the transceiver.
When the transceiver is used as an exciter for the
IC-PW2, the distortion generated by the RF power
amplifier is also reduced.
D How to use the DPD function
There are 2 ways to use the DPD function:
z Use only with the transceiver
This also applies when the IC-PW2 is connected,
but the linear amplifier circuit is OFF.
z Use when operating the transceiver as an
exciter for the IC-PW2
When the IC-PW2 is connected, and the linear
amplifier circuit is ON.
D Before using the DPD function
z Use the DPD function only with the transceiver:
The DPD single adjustment* (Adjustment only with
the transceiver) is finished at the factory. The DPD
function can be used without the adjustment.
* By adjusting the ALC circuit voltage and gain in the
FPGA, sudden changes in the gain of the ALC circuit
behind the FPGA can be minimized, enabling optimal
distortion correction.
TIP: When the DPD single adjustment is required
The DPD adjustment is completed at the factory
but may shift due to changes in characteristics
over time.
When the linked adjustment cannot be performed,
perform the single adjustment.
To perform the single adjustment:
• Connect a dummy load with sufficient input power
capacity to the transceiver's antenna connector.
L When the antenna SWR is 1:1.5 or higher, the
DPD adjustment may not be possible.
• The transceiver's internal antenna tuner must be
turned OFF.
• If the IC-PW2 is connected, disconnect it.
z Use the DPD function when the transceiver is
used as an exciter of the IC-PW2:
The DPD linked adjustment (Adjustment linked with
the IC-PW2) for each operating band is required.
L When replacing the IC-PW2, the linked adjustment is
required again.
To perform the linked adjustment:
• Link the transceiver to the IC-PW2 with the ALC
adjustment.
L If the IC-PW2's ALC adjustment is not completed or
the transceiver's DPD single adjustment is incorrect,
the DPD linked adjustment cannot be performed.
• Connect a dummy load with sufficient input
power capacity to the IC-PW2's antenna
connector.
L When the antenna SWR of the transceiver or the
IC-PW2 is 1:1.5 or higher, you might not be able to
make the DPD linked adjustment.
• Connect the transceiver to the IC-PW2 with the
optional OPC-2501 coaxial cable for dpd
feedback when performing the DPD linked
adjustment or using the DPD function.
L See the IC-PW2's instruction manual for details.
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