It may be motor noise but anecdotal evidence suggests that it happens even when the machines are off, eg on national holidays. Some kind of transmitter seems li

It may be motor noise but anecdotal evidence suggests that it happens even when the machines are off, eg on national holidays. Some kind of transmitter seems likely though. I know one construction site had analog video signals in the 2.4 Ghz range for their surveillance cameras. I accidentally found out when I did a range sweep on a video receiver for other reasons. PS I am in northern Europe, not the US.