I posted this on Atariage but I thought I'd try here too.
I purchased a modded Vader from a user who I've bought other things from before and he seemed to know his stuff and in fact this system does work very well and gives a nice picture on normal carts - except for one odd issue - some of my homebrew carts seem to give off what I can only describe as RF interference which seems impossible since the RF modulator has been removed. It only happens with some homebrews and not others and I'm assuming has something to do with the extra tech or lack of shielding in either those carts or on the board itself. Draconian, Lady Bug and Fall Down are the worst offenders but Space Rocks, Juno First and Colony 7 are fine.
Is there anything I can do to fix this situation? Pics below