[QuadList] RCA Models

[Dennis Ray Wingo]

The Ampex FR-950 instrumentation recorder was a 2" machine that also had octoplex heads.

The bandwidth was 40 megabits/sec in 1967!

Dennis Wingo



On Feb 26, 2011, at 1:29 PM, Dale Lamm wrote:

> Until joining this list, I'd never heard of an 8-head format for 2 inch 
> tape. I gather the main idea was to orient the pole pieces at some angle 
> with respect to each adjacent piece, then you could lay down two wideband 
> signals (perhaps video) at the same time, yet keep a measure of isolation. 
> Especially with an FM mod-demod, the capture effect would bolster channel 
> separation. There must have been a tiny track width with a small physical 
> separation. Recording one track on top of another would likely erase the 
> first track, because of the constant FM carrier. Please, someone with some 
> deep understanding of this kludge, tell us more.
> 
> What a hack! Was this for 3-D TV? [grin]
> 
> Or was this simply to give quad a "confidence head"?
> 
> Do you think it would be possible to record channel-A in the morning, then 
> go back and do a 60-minute insert using channel-B video in the afternoon? 
> Wow, two programs on one piece of tape! Don't need no stinkin' digital 
> compression.
> 
> I can see it now...
> 
> SALESMAN: Sir, if you buy this 8-headed recorder you can cut your tape costs 
> in half!
> 
> GENERAL MANAGER: That's wonderful! I could also liquidate some of my VTR's 
> and lay off a tape maintenance person!
> 
> 
> [snip]
> 
> If the octaplex recorder turned on every other head, it would be a standard
> quad recording, but with a 5-mil track, so I'm pretty sure that's not what
> was going on.  I think I get the "picture" that you are describing, and I
> assume that maybe if you were able to center the head between the two
> tracks, then perhaps the demod output would alternate between the stronger
> fields as they passed by.  I can't imagine that the results would be very
> good, but more to the point, I still can't imagine why the octaplex would
> have been used in the first place.  The only purpose is 2-channel recording,
> and I assume from what you have said that what you ended up with was one
> continuous picture, not 8 lines of one image alternated with 8 lines of a
> different image.
> 
> [end]
> 
> 
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