On Tue, 27 Dec 2005 18:59:56 GMT, Joerg
wrote:

Hello Jim,

Do it the way the original radio did it -- dynamotor. You can still find
them in the back room at a lot of military surplus electronics junk stores.


But then be prepared for some major restoration. The bearings of a lot
of these are nearly shot, mostly from sitting in an attic for decades.
It's like old pond pumps. They run fine for a few weeks and then the
racket increases, some weird noises appear, things get hot and they
seize up.

I restored an old Hammond organ. These generate the tones in a similar
manner. A motor (plus a start motor) and over a hundred pickup coils on
the long secondary shaft. 20 hours of hard work got it going again but
we have accepted the fact that some of the bearings are pretty much over
the hill. So it needs 2-3 starts to coax it to run without that mild
screeching in the background. Getting spare parts from a company that
went out of business 30 years ago just isn't going to happen.

Regards, Joerg

http://www.analogconsultants.com

what kind of bearings? - ball bearings are like tubes - thay have
numbers and substitutes. Bronze bearings are routinely made by
machinists. Babbit is hardest as it is poured in place but you might
be better off replacing them with something else like bronze. Bearing
technology is not all that complicated if you poke into the right
group of folks.