Borg-Warner System 80 12 inch records?

[mathewbailey08]

Has anyone used or familiar with the Borg-Warner System 80 teaching machine that used specially cut 12 inch records?
I have & it uses the 12 inch records mentioned with the matching film slides. The records use labels with a circle on one side & a triangle printed on the other side that match the corresponding circle & triangle printed on the handle of the film slide. (you insert the film slide & the record with the matching triangles or circles facing up.) Also,the
records have a second hole drilled in the label area which engage a pin on the turntable inside the System 80.
The records are played clockwise rotation by the machine at I believe 16 rpm & probably have a series of locked concentric grooves unless otherwise. The tone arm which uses a mono ceramic cartridge, starts at the label of the record when you insert the film slide. The film slide is a plastic resemblance to a punched card,because it has a series of both elongated & non-elongated holes which determine when either one of five buttons is pressed below the viewscreen
where the tone arm sets down on the record. I do know that Borg-Warner is the same company that made transmissions & also owned the Norge brand of appliances. (Norge is also the one that made appliances for Magic Chef,Admiral,Fedders,Western Auto & Montgomery Ward,until Maytag bought Norge.)

[Steve E.]

This is a question for Diamone!

[diamone]

Oh did I miss this one? I figured somebody would have PMed me by NOW (looks over top of glasses like a old man).

Somewhere - either on here, the quadraphonicquad forums, BSNpubs or the AntiqueRadios.com forums I have a whooolllleeeeeeee ``doctoral dissertation'' on just this very topic.

Quick and dirty version and slight corrections of some frequently-assumed-facts:
Cartridge uses (almost) a standard 89D PowerPoint half-mil playback system used in talking books for the blind - but wired for vertical playback.

As such - discs are cut vertically - but at the next lower speed that will give a full-tooth in a gear reduction scheme i.e. 16-2/3 gives 108 teeth so divide down to the next full tooth - 14.54 RPM I think. I lose track have to go back to my engineering and repair manuals and look it up. But it's a little slower than 16.

And the grooves weren't cut lock-style concentrically like you see on a Beatmaster loops LP - but they WERE cut 25 at a time - sort of like a Constant Angular Acceleration (CAA) format on a LaserDisc - where - instead of being truly Constant Linear Velocity (CLV) like a CD - it's a sort of hybrid between CLV and Constant Angular Velocity like on an LP.

Meaning - similarly on a CAA LD - a number of revolutions are cut at the exact same rotational speed - and then stepped down for the next group and so on and so on - instead the WHOLE DISC is cut CAV - but each 25-revolution segment was cut one-half-wave out of phase from the previous section - giving the record a sort of mini-checkerboard look.

The first players and the first set of lessons from 1968 WERE in fact recorded CAA in addition to each question being a half-wave out of phase from the previous. Of course this meant that each succeeding question could be a fraction of a second longer than the previous - so by the time they got to the end of the disc near the edge - the questions might be twice or even three times as long as those in the beginning of the lesson.

If you have a later player - presumably from the 1970 or `72 manufacturing run - and you have a lesson from earlier than that - of course the succeeding questions will play at a higher and higher pitch. But due to the amount of speed errors and scarce drive mechanisms that could do CAA without getting ``scrambled'' became WAY too expensive to produce as of 1970 that could keep track of the CAA at such a low rotational speed.

Remember it wasn't until twelve years later that CAA was perfected enough to run at the relatively HIGH rotational speeds of LaserDisc to make it worth pursuing. Even by the late 70's when LDs were still CAV only - an alternate format of the CED (SelectaVision) videodisc was attempted with a CAA drive system that only ran around six RPM i.e. started off at around nine and was down to four by the disc edge - and the CAA drive for THAT failed just as bad as it did for the early S80 in 1968.

So instead they had language experts make sure that questions in the first half of the disc contained as few sibilants as possible (F, S, V, etc) while leaving questions in the second half of the disc alone, due to the higher fidelity at the same rotational speed.

Be nice if somebody could assemble all thousand-and-some lesson boxes that were produced on every educational genre from 1969 through 1985. Just to see the primitive graphics if nothing else.

[diamone]

Four years later gonna add a video and one little tidbit about speed we didn't cover before.

https://www.youtube.com/watch?v=EXi06xoVlYM

This is the second version - the CAV - that had the most amount of lessons produced all the way up to the early 80s.

Each track is five seconds in length, so that would work out to 12 RPM - which would also work out for the gear teeth which would be 300 to an LP's 108.

Couple things I got backwards in previous posts from not having looked closely at the gear in forever.

The GE Magnadisc (Play-Talk) https://www.youtube.com/watch?v=47r2K1V4fpg doesn't run at 12 RPM it runs at 22-1/2 RPM (half of 45)

But the Assmann Magnadisc DOES run at 12 RPM - so I knew that ONE of the magnetic audiodisc formats ran at 12 RPM I just forgot which one.
https://www.youtube.com/watch?v=U6TbxT2uTS0

The Edison Voicewriter runs at a base speed of 24 RPM like UK talking books for the blind. https://www.youtube.com/watch?v=kxubd01Cxrw

So they are all mostly accurate - just the speed pairings were a little scrambled.
I know I used a talking book motor in a magnedisc I just couldn't remember which one.