[Elecraft] K2, PSK31 & microphone

[designer]

The posts on this topic mention an isolation transformer to 
"separate" the computer from the PSK audio line. So I might have 
missed the boat a little when I decided to ground the computer 
chassis/case to the common equipment ground. That is, I have a ground 
rod with a wire coming up to a copper tube/pipe behind the operating 
desk. I've attached all available ground connections - on rigs, power 
supplies and antenna tuners to that common copper.

Is that a mistake? Should I disconnect the computer or any other 
equipment from that common ground? What about the wing nut on the 
tuners - note that they are for unbalanced (coax), not twin lead or 
random wire. That is, I think it is supposed to be an electrical 
ground, not and RF ground.

Sort of related is the LCD screen - it came with its own power 
supply, but I run it off an small amp. accessories power supply that 
is also connected to the common ground.

I'm wondering if in my enthusiasm to minimize noise I have actually 
created more. I could and will experiment. But if someone sees a 
clear, "do it this way instead of that" to the setup, I'd appreciate 
knowing.

Thanks and 73,
Paul