Mic hum on EV630

[Phil Neal <rpneal44@xxxxxxxxxxxxx>]

Hey Y'all. Seems like the only time I have anything constructive to 
post, it's always a question. I hope they are questions that may help 
other people experiencing the same or similar problems. I have an EV630 
mic that has a wonderful tone. HOWEVER. 10, 15 minutes into the set, it 
starts developing a 60Hz hum. Sounds like a ground hum. Hasn't mattered 
whether I'm plugged into a PA or a stand-alone amp. Sounds great right 
outa the gate, but in a few minutes it starts to drive the sound guy 
nuts trying to figure out what part of his equipment is going bad.

Thanks in advance for any and all advice. It's all been good so far.

Phildo