With the Raspberry Pi 4B? I have always used the official Pi wall wart PS.? It is recommended that 5.1 at 3A be supplied to the Pi4's USB-C port, that supply meets that criteria.? In the past they have been readily available for about $7.99.? I have not had any issues with excessive RFI.? I have seen some 5v and 12v wall warts (switching supplies) that were so noisy that I had to remove them from service and put them in the trash because they even interfered with strong local AM stations.
