You should obtain a copy of Bob Baumbach's Victor "bible" titled "Look for the Dog". It's really a "must have" for anyone interested in Victor machines. It has a very complete accounting of the Victor models, including the orthophonics. And it has some appendices which detail the structure and maintenance of some of the machines including the orthophonic reproducer. There are pictures that show the structure of the ortho reproducer as well as cross-sections of the large ortho horns. Greg Bogantz ----- Original Message ----- From: "Jon Noring" <jon at noring.name> To: "Antique Phonograph List" <phono-l at oldcrank.org> Sent: Thursday, January 31, 2008 12:06 AM Subject: Re: [Phono-L] Some questions about Orthophonicreproducers--restorability, reproductions > Ron asked: > >> I've wondered about the use of rubber against the ball bearings. >> Wouldn't >> that interfere with their rotational function? Wouldn't a Teflon or >> brass >> ring backed by rubber be a better option? > > Yes, an interesting point. > > It probably depends upon the hardness (durometer) of the elastomer. > Silicone rubbers can be made pretty hard and so may be suitable as a > bearing roller surface. If any elastomer won't work, then teflon would > be my next choice. > > Personally, if I were to use any elastomer, I would probably use > Viton or similar fluoropolymer elastomer. Such fluorinated elastomers > (which can be thought of as a "rubber" teflon) are pretty darn inert > even in quite corrosive environments, and as far as I know they will > maintain their mojo pretty much indefinitely in typical conditions. > > Since I don't have an Orthophonic reproducer, and of course never saw > one taken apart, I'd love to see a schematic of one to better > understand what the issue is. > > Jon Noring > > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org