Posted by Bill Vermillion on 01/22/07 18:15

In article <gparp2t4rbmfg2952ucgiqcq4853263cc5@4ax.com>,
JoeBloe <joebloe@nosuchplace.org> wrote:
>On Thu, 04 Jan 2007 10:05:13 -0600, chrisv <chrisv@nospam.invalid>
>Gave us:
>
>>JoeBloe wrote:
>>
>>>LD is too huge, too bulky, and it presents the hardware designers
>>>with too many technical hurdles to make good gear for it. The wobble
>>>at the edge of a twelve inch platter can be huge.
>>
>>Too bad that the market didn't go for the "needle and groove" video
>>disk that RCA tried to make work, eh?
>>
>
> That's not what it was.
>
> It was a capacitive pick up stylus. No needle at all. No groove.
>
>http://en.wikipedia.org/wiki/SelectaVision

There was a groove which was part of a mechanical servo that guided
the parallel tone arm across the disk. Spacing was about 400
grooves/inch. [That phrase, grooves per inch, is actually an
oxymoron as there was only one very very very long grove from start
to finish.

Go back and re-read the wiki link to which you pointed, and you
will see that it does refer to 'needles' [erroneously] and grooves.
Like all thinks on wikipedia, the content is driven by the users
and is not always correct.

And just this morning I got the latest CED digest and it pointed
out one other uknown [at that time] problem with CEDs.

If you don't store them vertically - but store them flat in a stack
- then since the disk has raised edges on the outside and center
the start and end will be ok, but the center will often have the
caddy pressed down upon the tracks in the center and will start
causing skips when you hit the middle areas of the disk.

One owner did report that careful tuning of a couple of the
internal controls did minimize the problem.

Bill
--
Bill Vermillion - bv @ wjv . com

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