Is replacing the wall wart an option? I don't see why not, that's how I'd 
handle that. ON the hum with the speakers, I've found some do that, and some 
don't and don't know how to fix that. If you have a station ground on the HF 
radio, try removing it and see if the problem goes away on 10 meters, if you 
don't have one and can add one, try that. You can move the wires around on 
the PC speakers. I know with the ones I use now if the wires for the 
speakers run right along side the coax I can get that same thing but I move 
the cables apart and it goes completely away. You could try chokes or 
boiling the extra speaker wire. You may end up with new computer speakers, 
those are suggestions I can think of right now. I'm also in a very limited 
space and managed to fix that problem pretty easy and on 2 meters, I have 
100 watts available with no hum anymore just by separating the wiring. I 
pretty much have it set up so my coaxes are all together on one side of 
everything and everything else is on the other side with minimal over lap. 
It works out very well that way. It's a mess, but works.

-----Original Message----- 
From: Matthew Chao
Sent: Tuesday, December 08, 2015 11:11 AM
To: [log in to unmask]
Subject: Hum Everywhere in my Shack

Hi, Folks.  I seem to be having a grounding problem in my shack.

First, I've got a noisy wall wart that powers my network switch.  It
effectively blanks out some of my 2-meter repeater freqs on my TMV710A.

Second, on the other end, when I transmit on VHF/UHF, I get a hum
through my PC's audio.  The same thing sometimes happens on HF as
well, particularly on 10 meters.  Sometimes, I can hear my distorted
self coming through on my PC's desktop spekers.

Due to limited space, my PC and ham gear need to coexist on a 6-by
4-foot desk.  And neither wants to always play nice.  Any suggestions
that don't involve a lot of moving and shoving would be
helpful.  Thanks in advance.--Matt, N1IBB.