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QMX+ Low Image rejection at 160m,


 

Hello,
My newly built QMX+ is showing poor image rejection in the test suite, but only when for 160m, other bands look OK.
The image at 160m indicated -3.7, with both wanted and image around -16.
Looking at the Test ADC I/Q, the two signals show almost in phase when they should be 90deg apart for quadrature (other bands show quadrature as expected). The Q waveform is?
only about half the amplitude of the I waveform (again only on 160m, other bands having equal amplitude as expected).
I suspect both the above are different views of the same issue, but I am not sure where to look to further investigate the cause.
Any suggestions appreciated.
Best regards Trevor G6PSZ
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