But I think that I have problem with RX LO of WBX,
because I don't use TX in my application, I have two receivers.
External RF frontend brings HF to IF and is connected using coax
with usrp (LFRX). The other cable, UTP, connects io pins as well
as power of LFRX to external frontend. Interesting thing is that
when I unplug my frontend the spike doesn exist any more in the
spectrum of LFRX signal, which means that maybe noise comes via
UTP cable, because it's shield is not bonded to ground.
Well, again, you can offset the RX LO.