Jeff Wisnia wrote:


For longer than I can remember we've had a Crookes radiometer sitting on
our kitchen windowsill where it heralds the coming of spring by starting
to turn when the morning sunshines on it through the window.

If you're not familiar with what I'm describing, see this:

http://en.wikipedia.org/wiki/Image:C...radiometer.jpg

This morning I noticed that the radiomether was illuminated, but wasn't
doing its thing. I nudged it and it started turning but stopped in a few
seconds.

I gave it a closer look and saw that the metal "hub" the vanes are
attached to was "stuck to" the side of the bearing needle, and it looks
like it's magnetism and not an out of balance condition because it
seems it will "stick" anywhere around its periphery.

I'm guessing the hub and the needle are both made of steel and somehow
got magnetized.

I don't own a demagnetizer big enough to fit the whole bulb in, and
before I spend the time winding a BF coil and energizing it through a
transformer and variac, does anyone have any ideas what else I could do
or use to attempt to demagnetize this old family friend? (Without
busting the glass that is.)

Any old-school TV repairman will have a
degaussing coil about a foot in diameter
and would probably do the job for free.