The DPI/DSI 22 pin ribbon cable is shielded but not grounded to either at the Pi4 or the display board.
Two separate modules. Where to ground properly?
Please send me a picture or video of your V2, V3. Antenna not attached. IF to 70.
Put your SBITX in LSB on any band. Now take a video or a picture of your spectrum/waterfall display.
I’ve attached a picture of my V3 and the obvious noise. This is after I did the 5v BB and internal shielding. It was much worse.
Kb4yho