Jean-Louis F6AGR said:

Let me introduce to you a new candidate to the "Ugliest 137 kHz QRM
generator Challenge".
I'm talking about the Philips SL.E Pro 16W Warm White light bulb.
This light bulb (quite expensive) saves energy and uses only 16 watts AC

to

produce the same light as a 100 watts conventional light bulb, but

generates

an horrible noise (multiple discrete frequency lines) all over the 137 kHz
band.

About three years ago I tentitively tried out one of these energy saving
bulbs and didn't find any interference throughout the LF/HF spectrum and
have, over a period introduced more into the house. These bulbs do save a
lot of energy, which is a consideration with cost of energy in this country.
So perhaps we could draw up a list of low energy bulbs that don't cause
interference.

Most of the bulbs I have are cheap ones from Woolworths and are described as
BIAX V257 made by GE Lighting.

As regards electronic 'transformers' could the fix be just to replace it
with a conventional transformer?

Peter, G3LDO