Hello Bo,
Have you checked the volume level you are feeding the uBitx? The mic amp isn't expecting more than 40mV.
Also did you have any attenuation turned on the ICOM? The manual says it has settings for 10,20,30 dB attenuation. (I'm terribly curious if that's a hardware attenuator or software based. Looks to be hardware based according to the service manual. 10dB in tuner unit, 20dB in RF unit. Okay.)
I wonder if the spurs will go mostly away with 30dB ATT and checking that the sourdcard feed to the mic amp doesn't exceed 40mV.
The service manual says there is a 20dB voltage controlled attenuator to keep the ADC from getting swamped. Your two radios are so close I'm still sure the 7300 is showing you spurs due to close proximity.
Those are the first 2 things I would check.
73 de Jacob AG7CT
