I don't think that either speed or groove size can be patented. For an interesting account of the Columbia LP, try http://www.classicalmusiccd.com/audiohistoryLP.html - Ed Wallerstein mentions the RCAVictor lp, too. I've read elsewhere that recommendations were made (I think by Wallerstein) for saving the RCA program by developing a smaller, jewelled stylus, lighter pickup, and steadier motor, but the interest just wasn't there.
All 10" Program Transcriptions which I have seen were/are made of standard shellac-formula stuff; the 12" of Victrolac, which was covered in US patent number 2130239. "Vinsol" is the plastic, extracted from shredded longleaf yellow pine stumps, while PVC (which we call vinyl) is 57% chlorine and 43% petroleum. ----- Original Message ----- From: "Doug" <cdh...@earthlink.net> To: "Antique Phonograph List" <phono-l@oldcrank.org> Sent: Sunday, April 30, 2006 8:54 PM Subject: Re: [Phono-L] Victor long playing records > Before I read the other related posts, I can MAYBE answer this. Columbia > succeded in recording a wide (frequency) range microgroove disc for 33 1/3 > speed on a soft material that was beginning to appear on 78 RPM records > (Remember RCA's "Red Seal Deluxe" records?). I'd say that Dr. Goldmark > just > used the best of all the former techniques and put them together on one > new > disc. > > Certainly, Edison went to a microgroove cut, because it made sense. He > should have used an electric motor so he would be able to have the 33 1/3 > speed for a full playing time. But Edison had an aversion to electric > notors > in phonographs, though he could have had them; others did. Victor was wise > enopugh to use the then standard 33 1/3 speed. Goldmark simply combined > those two factors and made his microgroove LP discs. Of course, it was a > tad > more complicated that that, but it was the logical combination of > features, > as I see it. > > One other thing that came to mind. Let's say that Edison patented the > microgroove cut in 1925 (or so). His patent would have expired in 1942, 17 > years later. Probably an Edison patent was why RCA didn't use a > microgroove > cut pitch. Was the 33 1/3peed patented? I doubt it. It was in wide use in > the the thirties through the forties. But, if Edison did have a patent on > his microgroove records, Goldmark was free to use the technique because > the > 17 year patent life had passed. > > Now, on the exacr character of materials on the Victor Lp discs, I don't > doubt for a second that there was more than one material for the LP > records. > We're going to have to find someone who has lab notes or something from > Victor, explaining all of this. > > > > ----- Original Message ----- > From: "Robert Wright" <esrobe...@hotmail.com> > To: "Antique Phonograph List" <phono-l@oldcrank.org> > Sent: Friday, April 28, 2006 8:03 PM > Subject: Re: [Phono-L] Victor long playing records > > >> To Ben, Doug, Peter, and all the fine folks of this list, my profound >> thanks >> for your fascinating and thorough contributions on this subject. In a >> matter of days, I now know more than I had learned through some 15 years >> of >> incidental research. I can't thank you enough. >> >> A bit more info on materials used: My 12" Stokowski PT's are flexible >> vinyl >> (Vinylite?), while all my 10" are the same brittle shellac as normal 78's >> of >> the era. I would think "Victrolac" was a slightly (if at all) modified >> shellac formula that was more about marketing 'the next next big thing' >> than >> being a revolutionary material (no pun intended). I am curious exactly >> what >> "Z shellac" is, a notation I've seen on VE scrolls in Nauck's auctions. >> >> We do have two questions so far unanswered, to which I'd like to add a >> third: >> 1. Do we have a way to find out the exact dimensions of the stylus >> intended >> for use with Program Transcriptions? Does anyone know of a 'white paper' >> on >> the subject buried somewhere in the old RCA Victor files, perhaps? >> 2. Does a complete list of PT's exist anywhere that we know of? Is >> there >> a >> way to know which releases used matrices specially recorded for LP vs. >> dubbed PT's? >> 3. If 33.3rpm Vitaphones were a Victor concern (right? weren't they?), >> and >> Edison invented the microgroove (as well as the micromicrogroove with his >> almost unplayable 80rpm LP's), and Victor combined a type of microgroove >> with their PT LP's, then exactly what did Columbia get credited for >> "inventing" in 1948? >> >> >> Again, many thanks to you all, >> Robert
