Hello Andy,
I am not aware of an adjustment for image rejection, as that is in the software unlike in the QCX line of transceivers where it is analog.??
What is the Audio Sweep showing as far as image rejection?? When I do my scans with a dummy load connected I am seeing better than 60db rejection.
I would also make sure you are on the latest version of firmware 1_02.
One last point, I remember one of the changes of version 1 to version 2 of the hardware was adding bias resistors to the BPF switch to help with strong signal rejection.? Here is the message link:
/g/QRPLabs/message/7467573
Evan
AC9TU
