This week I received an old Art Deco extension speaker, I don’t have a make or a model for it, so can’t date it, but guessing from the moving iron driver design below, and the paper cone that was attached to it, I’m guessing 1920s.

It was unfortunately open circuit (faulty) so wasn’t going to be any more than a desk ornament unless I took a look inside. So that’s what I did. I was lucky, it contained two electromagnets in series and with a quick test I was able to determine that one was blown, the other was OK.

So, after bypassing the blown coil and re-assembling I was happy to discover that it now works, and works really quite well too!
It’s now connected to my early 30’s radio kit (box) posted here.