We are booked for this venue in another month.

What should I look for exactly?

What are the different causes for "noise on the line"?

Lookin' for guidance and easy solution!

I know, there isn't one.

We never had this problem before with our gear or with the same gear at this or other venues.

On Friday night everything "A OK", Saturday night with no changes we become a "big ass radio".

Its bit mysterious to me.