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Re: [Rollei] GX/FX selftimer??now record speeds!



At 04:24 PM 06/03/2002 -0700, you wrote:
>Hi Richard!
>
>     I was under ten, but had two older brothers and can remember their
>Elvis and Fats Domiono records on 78, as the family didn't have a lp
>player yet.  Also, somewhere in the mid-fifties, the 45s appeared.  Rich
>
>
   45 RPM records came out about a year after 33's. RCA was caught with
their pants down and rushed to get something on the market. 
   Curiously enough the 45 was was really a better design: Columbia's lp
record was really a sort of glorified makeshift. Columbia had been making
its master records on 33-1/3 RPM broadcast type transcription records from
about the late 1930's. I think this was the inspiration for the long
playing record. RCA had experimented with long playing records in the very
early 1930's but the system was never successful. Those records are now
very valuable collector's items. BTW, there were also long playing cylinder
records!
  There is an optimum speed for a record which is calculated from the
maximum inner and outer diameter of the grooves and the required minimum
groove velocity. For a 10 or 12 inch record its not 33-1/3. 45 is exactly
right for the 7 inch records RCA was making. In fact, its closer to optimum
for 12" than 33-1/3. RCA's design also included the one inch center hole to
allow much more accurate centering and less wear. It also made possible the
clever record changer mechanism RCA introduced with it. 45 records also
have thickened lable areas and a thick annulus at the edge of the record.
When stacked the records are supported by the center and edge protecting
the groove area from abrasion. 
  The place RCA missed the boat was in total playing time. They were stuck
thinking of the new records as replacements for 78's which have a maximum
playing time of just shy of five minutes for a 10" and about 6-1/2 minutes
for a 12". These are absolute maximum times if the inner grooves are
allowed to be cut further than normal practice. When longer pieces were
recorded they had to be split up on multiple sides. RCA evidently did not
understand that the simple interruption of the music with then then used
system was very undesirable. So, 45's got confined to single records and
33-1/3 lp's became standard for classical and much more popular for album
records.
  33-1/3 rpm was anything but new. The speed was introduced for the 16 inch
sound track records used with the Warner Brothers-Western Electric
Vitaphone system for motion picture sound. Eventually, similar 16 inch
records became standard for reference recording of radio programs. Most
broadcast turntables would play at two speeds, 78 and 33-1/3.
  While transcriptions were not used on the air much before the late 1940's
they were very widely used for reference recording of programs. A reference
recording is one made as a legal record or for sponsors or cast members to
hear. Most of the old radio programs heard now were preserved on this type
of record. 
  The quality varied. The best of them were of very high quality although
what you hear now are often many generations removed from the original
records. 
  When the Vitaphone system was introduced low cost and simplicity of
reproducing equipment was considered formost in order than theaters would
be encouraged to convert to sound. Some unfortunate compromises were made
to that end which lived along in the 78 rpm record. One compromise was to
drop the use of diamond or saphire tipped needles, long standard for
acoustic phonographs. The reproducer used a steel needle, not very
accurately ground. One needle per play. The pressing material of which the
record was made contained a small amount of abrasive to shape the needle as
the record played. The records were started from the inner grooves, unlike
most records, since the requirements for the fit of the needle are most
critical there. The groove velocity, of course, is slowest there and the
wiggles tighter for a given frequency. As the record played the needle was
worn but the groove velocity was faster so the loss of high frequencys and
increased distortion was not as obvious. 
 The records wore out very quickly and had to be replaced often. Needless
to say the sound on disk system for motion pictures did not survive. Sound
on film became popular almost as soon as it was introduced. The last sound
disks were distributed about 1933 but sound on disk was essentially dead by
1931. 
  A brief note about RCA. Willim Paley of CBS and David Sarnoff of RCA had
a personal vendetta of some sort, perhaps only jealousy. CBS was the
primary competitor to NBC but was originally only in the broadcasting
business. CBS bought the Columbia Ponograph Company mostly to compete with
RCA's Victor Record division and to obtain some manufacturing facilities.  
  The development of the long playing record at CBS and their attempts at
developing a color television system were the direct results of this
personal rivalry.
  CBS, BTW, avoided the use of RCA equipment to the degree that they could,
considering that RCA was one of the two foremost manufactureres of such
equipment. CBS went to the extreme of removing RCA name plates and trade
marks from microphones and TV cameras which might be photographed. CBS
network radio plants were equipped with either Western Electric or
independantly made equipment, including transmitters. RCA microphones were
unavoidable but were disguised as mentioned above. 
  This is all so OT I am hesitant to post it.
- ----
Richard Knoppow
Los Angeles, CA, USA
dickburk  

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