Why did the idea of a 7" 45 RPM record originate? Simple, it's just plain business. RCA engineers accpeted an invitation from Columbia Records to tour the factory and view the new 12" 33 1/3 RPM vinyl record and the newly designed cutting/pressing equipment. Little did Columbia know, when RCA released the first 45 RPM records and players in June of 1949, the design had been created ten years prior. RCA held this invention in secret for ten years, mainly due to the slow economy. Once released, the players were sold until 1958.
Turntable (No Amp)
This RCA picture appeared in the June, 1949 issue of Broadcast News, published by the Engineering Products Division of RCA.
Notice the various colors of these new record box sets. So, what did color have to do with it? Just this:
Popular Classical...(Midnight blue)
Country and Western...(Green)
Blues and Rhythm...(Cerise)---(Notice--they do not call them orange)
Why the large 1-1/2" center hole? The idea of cosmetics and proprietory use was not the consideration. The large diameter hole reduced stress on the record. Records with a small center hole became worn after lots of use. In addition, this new 45 provided another feature. The label area of the record is raised. This prevents the playing surfaces from rubbing together when stacked on the automatic changer. Make no doubt about it, this whole 45 thing was well thought out.
Notice that each RCA 45 RPM record has an eight digit code. The first letter/number will tell the date of the master. The record was generally pressed and released shortly after this date. Below, you will find a chart from 1950-1975. Grab a few of your old RCA 45's and check it out.
Records pressed before the 45, were also coded, but this page is devoted to the 45.
Do you remember the vinyl quality of the 45 from the 60's through the 70's? It was awful! After a few plays, they were done. Brand new, these records had no luster. Luster means alot when grading the quality of a record. While the UK was producing top quality 45 vinyl, US releases were pressed on recycled vinyl. Compare a copy of Eric Burdon & The Animals on an MGM US release, with a UK pressing.