"MB" wrote in
:

If by "anti-dirt device" you mean something removable that can be
cleaned-- no, it's a sealed unit.

I just wondered; some have a sorta grounded plate, etc, but I've never seen
one that eally captures the dirt.

I'm a bit of a martyr to me tubes, and as they clearly (except yours!)
precipitate rubbish, and one which would also collect it would be nice.

But I don't really want a big air treatment plant.

mike