Shure PSM 600 634.775
2 Line 6 Relay G30 units (new, ch. 1 & ch. 6)
Audio-technica atw r2100a wireless mic
Shure ulxs4 group 3 ch. 3
Shure Psm300 p3t (new) grp. 1 ch. 1
I did a web search and found WAY too much info. Shure has charts but I got lost in the models and groups and channels and frequencies.
Help!
It’s always a faulty ground.
Give us more info.
I am sorry but I am clueless about that stuff.
Not nearly enough info in the OP to begin to figure anything out.
Most important thing: what frequencies are all those devices using? The only one listed was for the PSM 600.
Cafe >> General Questions.
If you say so. It about playing music. 
Exactly what kind of “Interference” are you talking about?
Just white noise? Static?
Crosstalk?
What?
And the most basic procedure is to turn on one device at a time until you notice the problem (start with them all off). Then move on to other diagnostics if you find nothing.
Just throwing this out there:
When I had a headset mic with a battery pack, Duracell 9Vs were 1/16" shorter than other makes; caused all sorts of problems–dropout and crackling for starters. Had to shove a thin piece of cardboard in there to make the batt contact. Once that big box o’ batts was used up, on to Rayovac.
Now, if you have the Spinal-Tap-at-the-Air-Force-base problem, can’t help you.
Ah, yes, the old “battery doesn’t get pushed against the contacts” problem. I remember it well.
I’ve had the “breaker breaker” issue on occasion, altho’ new, digital units are less prone to it.
Thanks for all the input, I’ll try some of these ideas and see if we can figure out what’s happening.
Throw the guitar down, and storm dramatically off-stage.