freddie_b just to make sure: Have you unplugged USB chargers etc for testing? They often cause such issues.
I have a VW T6 with Dudu7, USB DAB-Adapter and use the OEM FM mirror antenna via an active splitter. I get ok reception (drop outs only in rural areas, sometimes).
I also use USB chargers, mine are ok.
I recommend reading the thread on XDA, there are various experiments with antennas, it's admirable what some are willing to do:
https://xdaforums.com/t/improvement-of-dab-signal-receiption-quality.4672640/
Try DABdream DAB/DAB+ USB Radio:
https://xdaforums.com/t/dabdream-dab-dab-player-for-usb-adapters.4638309/
It's a shame that Dudu7 doesn't have integrated DAB+, the German Dynavin has solved it well, I like that it has built-in DAB+. It supports automatic switching back and forth between DAB and FM (Seamless Blending), the question is whether it really works.
https://www.youtube.com/shorts/IWr9lfdQEN4
I asked this question to. Why no build in DAB? Space enough.
Snap, mine is also installed in a VW T6! No usb adapters or LED lights. OEM mirror and window mounted antenna returns the same results. I am in a rural area, so maybe my expectations are too high, but I never had an issue with the OEM stereo. I could install a roof antenna, but don't really fancy drilling holes in my van.
JhonnyD I think DAB has limited market globally. Used mostly in Europe as far as I can tell.
Pavel-71 Thanks. I have already skimmed through those, but will have a more in-depth look 
freddie_b Then we need a DUDU EU head unit 
Most of the time i listen to internet radio.
In northern Germany they are sending with to less power.
Even Danish stations have a lot more power than ours.
So if you have a sharkfin antenna, you are in trouble.
So the solution for me is, internet radio.
I had the same problem with the DAB adapter. It was the antenna that was poor quality. I live in Norway, and the antenna was pretty much useless. I installed a roof antenna with DAB and FM, and the signal is now very good.
JhonnyD Ah but in rural Britain we have rubbish DAB and rubbish mobile internet as well so there really is no hope
DUDU EU has got a ring to it. I like it
I use this one from Amazon [https://www.amazon.co.uk/dp/B0D2MNRKWC?ref=ppx_yo2ov_dt_b_fed_asin_title] and I am surprised how well it works with the windscreen mount. I have had windscreen mounts before with bad performance but follow the instructions and definitely, as suggested above scratch/grind the paint off the metal and smooth it out with fine emery cloth or sandpaper and clean it, make sure all the copper strip is in contact with the bare metal. Also give the window a good clean before sticking, yes its a bit of a faf but its worth it. I have 92 stations with full signal and very few dropouts
robdx2 Thanks. If all else fails I may give one a try (although I did read somewhere that most of the devices actually use the same chip?).
