I had the Oudie powered through the supplied 12V to 5V interface cable supplied with the Oudie. I used a Y power cable from the battery to connect to the interface cable and the other side of the Y to ships power. I did not have the Oudie powered from the aircraft bus bar.

I used the Oudie supplied interface to power the Oudie and the Nano from the aircraft battery and also to move data between Oudie and Nano. Task data to the Nano and GPS data from Nano to Oudie, and final retrieval for final Nano igc file from Nano to Oudie. Nano on the USB side and the Oudie on the RJ 45 plug.

No noise on the radio.
Hope the helps.

BillT