How a 78 is made

[StarTMachine]

Hi Folks

I just found this: How shellac records are made 1942, Narrated by Milton Cross.

[youtube]http://www.youtube.com/watch?v=qZ5PQSaDYgU[/youtube]http://

Ahhhhhhh the good old days. Would have liked a job in that factory.

[clevelander]

Fascinating piece of film history!

[StarTMachine]

Hi Clevelander

Yes it is. And, just imagine all the master matrixes ever created are in a vault somewhere. Must be a big vault?

[epigramophone]

Hi Clevelander

Yes it is. And, just imagine all the master matrixes every created are in a vault somewhere. Must be a big vault?

Sadly not all of them. Much has been lost.

[CarlosV]

The record changer shown at the end of the film is quite interesting. I suppose it is the RCA Magic Brain that plays records on both sides without need to flip the disc.

[gregbogantz]

Yes, that record changer is the RCA model RP-151 and it plays both sides of the record. It has two pickup heads on the same tonearm and two crystal cartridges, one for playing the top of the record and the other for the bottom of the record. The platter reverses direction when playing the bottom. The radio/phono is the model V-225 and it is the only set that ever used the RP-151. These units were from the 1942 model year. The RP-151 proved to be fussy and a fairly poor performer which is probably why it was never used on another model set.

[CarlosV]

Quite interesting, Greg, thanks. Judging from the sample record sleeves of the period that advertise the Magic Brain,RCA invested considerably in marketing this changer before retiring it.

[De Soto Frank]

Wonderful video - thank you for sharing !

For many years Milton J. Cross hosted the Metropolitan Opera radio broadcasts...

[gregbogantz]

RCA used the "Magic Brain" moniker to describe several different features of several different models of radios and radio/phono sets during this period. It was just marketing hype. It seldom actually referred to anything "magical" or "brainy" or even particularly noteworthy. The RP-151 2-side record changer was probably the most innovative thing they called a "magic brain". The term was most often used to describe their new RF/IF electronics section of their radios. This "magic brain" section was a separate sub-chassis with the RF and IF tuning circuitry crammed into as small a space as they could put it. Which makes them a real pain in the butt to restore today. This was necessary to extend the RF frequency range well into the highest frequency shortwave bands with improved performance over earlier designs. Except there was nothing "magic" about it. Or "brainy". Or new. Philco had been doing this RF/IF sub-chassis design starting in 1937, but they didn't have a marketing wiz to come up with a silly name for it.

Philco was actually considerably more innovative in the mid to late 1930s and up to WWII than was RCA, coming up with such genuine advances as automatic frequency control (AFC) to prevent drift off the desired radio station which Philco labeled rather descriptively as "Magnetic Tuning". This feature would much later become commonplace in FM radios of the 1950s and later. Philco was also one of the first users of woofers and tweeters in their sets (ca. 1936), mated with genuinely high power amplifiers, and they were one of the few makers to have variable IF bandwidth tuning which allowed for genuine high fidelity performance on the AM radio broadcast band. Almost no AM radio made in the last decade has this feature. Philco was also the first to use what we now call "passive radiators" in their speaker systems which Philco called "Acoustic Clarifiers". These looked like speakers with a paper cone in a metal basket, but they had no magnet or voice coil. They were specifically-tuned physically resonant sound radiators. They functioned as acoustic boom filters to reduce the annoying cabinet boominess that was typical in big consoles of the day. Consequently, Philco labeled these sets with decals on the front panels as "High Fidelity". And they really were. In 1936. In 1939, Philco introduced the FIRST WIRELESS remote control system in their top consoles. It was RF-based, not infrared like most of today's remotes, so it would work thru walls and between floors in the house. You could use the remote to change from radio to phono operation (and back), control the volume, and you could reject the current record on the changer if you didn't like it. In 1941, Philco developed the "beam of light" phonograph pickup which was unique in the industry - it used a photocell to generate the signal from the stylus riding in the record groove. All these innovations were leading the electronics industry in the US during these years, but Philco never felt it necessary to proclaim any of it with a silly name.