Quote Originally Posted by Kitwn View Post
Sorry, I missed this comment first time round:
Actually, yes. As far as I'm aware it's the largest wireless transmitting antenna in the southern hemisphere and is about 14Km away from the CNC machine.
It transmits VLF signals for the US Navy Submarine Fleet. I thought this could be giving your sensor LEDs a buzz. The sensors themselves generate an ac em field, but I don't know the frequency, but there might be some heterodyning.

Just a thought, but it might have no merit.