Hi Walter S,
Totally agree with your comments, Have been Involved myself, with related incidents
First one, was Industrial flood lights on a Factory used as an FM TX Site for a community station
The 50 megs studio link worked perfectly, until floodlights came on at dusk, then...
they Totally wiped out the 50 meg Link RX, I tried running lots of watts at the studio end but
could not get over the interference at the FM site (and my extra power amp made the studio desk buzz)

I went up on the factory roof, tried a Belling lee filter in the mains lead to the light,
that was nearest to the 50 megs link antenna, did nothing, Moved the link antenna to other end of roof
Still no joy, So I unbolted one of the Industrial Floodlights, to see If I could Fit Belling Lee Filter inside it

With it in bits, I was amazed How small the Electronic "Ballast" was, usually medium power switch modes
use a quite chunky transformer, to handle the wattage (200W etc) going thru them, but...
The tranny's in the lights causing the interference, were long, Square and Less than an INCH diameter square,
(all Potted in epoxy)... Using a 49 megs 'CB' handset, I found the RFI hash, was Not radiating from the cables
but from Each floodlight itself ! The Type of switch mode used, does not use a Transformer with Two Windings
Only One winding used, but I suspect as the tranny size is so small, They are using a round ferrite Rod
NOT a Proper Core, so not a closed magnetic circuit, The waveform on my scope was a total square wave
I have heard other people have found these type of lights jamming up to DAB freqs (200 Megs)
Did not have time to have a look at the spectrum coming out of it
How do they get away with this crap??

Rod Watts