[RFI] USB 3.0 RFI

[Wes Stewart]

I use several HP Elitedesk SFF computers in my office and ham shack.  I like them because of reasonable size, I5 or I7 processors, room for a second internal drive and a plethora of USB ports.  I buy these second-hand from a thrift shop.  They get them from companies that are upgrading their hardware.  The thrift shop has an IBM retiree, who I've gotten to know, who refurbishes the computers and will even configure one to my needs.  Because these were corporate units, that ran on wired networks, they don't have WiFi, so I use WiFi  dongles to connect to my home network.
Unfortunately, none of these are Win 11 compatible, so I contacted my buddy and found a newer generation one with a processor that Win 11 likes.  I've been slowly loading all of my programs onto the new one so that I can do a switch into the hamshack with minimal downtime.  I just plugged in a new WiFi dongle and it didn't work.  So I swapped in the one from the old shack computer and it didn't work either.  I put the new adapter into the shack computer and it worked fine.  After a bunch of fussing I learned that the USB port on the newer computer that I was using is a USB 3.0, where the same port on the old computer is 2.0.  If I put the adapter in a 2.0 on the newer computer it connects just fine.
This may be common knowledge but it was news to me.  After some research I learned that USB 3.0 generates enough RFI to interfere with 2.4 GHz WiFi.  https://www.usb.org/sites/default/files/327216.pdf