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Mica Replacement tips
Posted: Sun Aug 01, 2010 5:39 pm
by nsjames
So, I have this machine:
http://forum.talkingmachine.info/viewto ... f=2&t=4407
it likely is an OkeH tonearm. I've measured the mica at just about 2", but I assume there's some more under the brass ring.
Pretty sure that the 2 1/16 mica from antique phono supply will work. What else do I need? Gaskets?
Anything special about installation?
School me on mica replacement.
Re: Mica Replacement tips
Posted: Sun Aug 01, 2010 10:36 pm
by Brad
I would suggest starting out by checking this step by step rebuild for a Victor exhibition. This should answer a lot of questions and head you in the right direction:
http://www.nipperhead.com/old/rep_exhib.htm
Then check out Antique Phonograph Supply Company for replacement mica and gaskets/tubing.
Re: Mica Replacement tips
Posted: Mon Aug 02, 2010 10:55 am
by nsjames
Yeah, Antique Phono was the place I had planned on ordering from. I was going to order the Heinneman rebuild it and a few hundred soft tone needles.
Someone has mentioned a glass replacement, is the glass better than Mica?
This unit will likely be a conversation piece and played sparingly. I just want it to be in proper working order.
Thanks for the link to the rebuild. It looks like something I can figure out pretty easily.
Re: Mica Replacement tips
Posted: Mon Aug 02, 2010 1:49 pm
by Brad
I know that glass was used in the early Edison automatic reproducer, but I don't know if it was ever used by anyone else. With glass, you have to glus the linkage eyelet to the center of the glass diaphragm.
Re: Mica Replacement tips
Posted: Mon Aug 02, 2010 4:39 pm
by nsjames
I'll stick with the Mica then.
Re: Mica Replacement tips
Posted: Tue Aug 03, 2010 3:09 am
by gramophoneshane
Is the original mica diaphragm damaged? It looks fine in the photograph, so shouldn't really need replacing.
Re: Mica Replacement tips
Posted: Tue Aug 03, 2010 11:15 am
by nsjames
There's a "buzzing" noise from the mica while it's playing a record. There's also some cracking around the outer edges that the camera couldn't pick up in the photo.
I figure that since i'm working on it I would just do the Mica and not worry about it for another hundred years.
Re: Mica Replacement tips
Posted: Tue Aug 03, 2010 12:34 pm
by gramophoneshane
Fair enough. If there are any cracks or delamination of the mica layers, then it indeed should be replaced.
Re: Mica Replacement tips
Posted: Tue Aug 03, 2010 4:23 pm
by nsjames
I figure the buzzing is from the small cracks and the edges rubbing against one another.
Re: Mica Replacement tips
Posted: Fri Aug 13, 2010 9:00 am
by JerryVan
There is nothing wrong with your mica. The buzzing is due the rubber gaskets being shot. The mica is buzzing around in the gap between the dried up, shrunken gaskets. Carefully disassemble the reproducer and install new gasket hose, (available from the suppliers), and you're good to go. Also, should re-wax the connection point where the arm screws to the mica.