You guys are right. It is the 300B pin interface. I went through and sanded the pins, but I couldn't get down into the socket. How'd you guys do that?
So, then I put it all back together and tested and the static was gone. But then I noticed I didn't but the orange o-rings back on. When I put those back on, the static came right back. So, then I took them off and put the 300Bs back on. No more static.
So, it looks like it is an engagement issue with the pins of the 300B and the socket. Is there any way to adjust those?