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A7438-2EX © 2017 Icom Inc.
To remove a sharp spike when setting a low sampling rate value
If the sampling rate value is too low, a sharp spike (a DC) is displayed at the LO frequency position.
The DC is a constant offset in voltage, the Left and Right (I and Q) ADCs produce, due to error.
To remove the sharp spike:
•Set a higher sampling rate value.
or
•Adjust the IQ balance. (Option [F7]
➔
Calibration Settings
➔
DC Removal Calibration for RX)
To adjust the IQ balance
1. Set
RF Gain
to “MIN” on the IC-R8600 I/Q Settings screen. (p. 3)
• Only the sharp spike is displayed.
2. Open “DC Removal Calibration for RX.”
3. Click the displayed mode to set “IIR-Highpass (Auto).”
• The software automatically adjusts the IQ balance.
4. Set
Mode
to “Constant (On).”
L
If this setting remains “IIR-Highpass (Auto),” the software removes signals near the LO frequency.
5. Adjust
RF Gain
on the IC-R8600 I/Q Settings screen.
NOTE:
When you change the sampling rate value, adjust the IQ balance again.
a sharp spike
(a DC)
