Owain wrote:

John Nickum wrote:
Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?
It's actually for testing an old Geiger counter that was a Maplin kit.

Would tritium dials from Trimphones be an acceptable alternative source
of radioactivity?

According to the article referenced by John Ruum, the tritium would be
mixed into a waxy substance - and presumably sealed in glass which
would prevent escape of the alpha particles.

Breaking it open could be messy, so I think I'll pass on that one. :-)

--
John