Skyview Radio "constant low buzzing"

[AGLyme]

Dear Experts.. .
Factory installed setup in my Flight Design Light Sport, about 155 hours problem free.
Returning from a flight the other day and as I entered into my home pattern, this "low, constant buzzing" started up. Not affiliated with any buttons pushed, etc... just out of nowhere. I can still hear transmissions, and, I can still send transmissions. I asked for a radio check and a fellow pilot responded "loud and clear".
I figured it was the field radio. This morning, while on the ground, I turned the Skyview on and the buzzing came back immediately. I checked other frequencies, same buzzing noise. I turned the radio off, fiddled with the squelch... no changes. The buzzing does not stop, nor does it change when RPM's are applied... etc. I am stumped. It is bad enough that I cannot fly. I am planning on an 8 hours flight to Illinois in 2 days so I hope I can get this fixed soon. Thank you for all your help. I attached a photo of my setup.

PS: when i get back to the airport, I will check the second set of headphones...

 

[Raymo]

Have you tried turning off things like alternator (alt field) and other items to see if something is causing the noise?

 

[sshae]

Not sure if this will help, but when I built my RANS S-20 I found the USB power hub, similar to the one in your picture, I installed caused a buzzing and squealing in the Skyview intercom I was using in conjunction with an ipod for music. I ended up putting a ground loop filter in the line between the ipod and the intercom.

 

[sstearns2]

Yes, +1 for any USB chargers you might have going. RF is magic.

 

[AGLyme]

Thank you...