Hi Barnacle Bill, Above comments were posted, by Stephen Sullivan on August 24, not myself

The Noise from overhead ADSL phone lines, especially to farms, is really strong, poss. more Level
But one main source of AM Interference, is SMPS in Garden Floodlights

Some of the Factory used High brightness ones, Wipe out 50Mhz, and some even wipe out DAB as well
I took one to bits, and the Choke (it's a single winding, not a tranny)

and it was Under 1 Inch square, and about 4 inches long, appears to be an Unclosed magnetic circuit
i.e. A ferrite Rod, and the square wave racket, comes direct from this, not the mains wiring
Different Regs apply to Lights on factories, so they get away with this crud

The floodlights for Home use, have a proper transformer, but often the Mains Line filter, left out the PCB
so the Hash, then radiates from it's mains cable

Rod Watts