Posted by Richard C. on 01/07/07 02:14

"JoeBloe" <joebloe@thebarattheendoftheuniverse.org> wrote in message
news:5pksp2pbgb12u5brhnh24elr3b26mismm9@4ax.com...
> On Fri, 05 Jan 2007 01:23:06 -0800, Tim Smith
> <reply_in_group@mouse-potato.com> Gave us:
>
>>In article <gparp2t4rbmfg2952ucgiqcq4853263cc5@4ax.com>,
>> JoeBloe <joebloe@thebarattheendoftheuniverse.org> wrote:
>>> >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
>>
>>From that page (underlining added):
>>
>>======
>>SelectaVision used a special medium known as a Capacitance Electronic
>>Disc (CED). The VideoDisc was a 12 in (305 mm) platter housed in a
>>special caddy. The video and audio signal is stored on the Videodiscs
>>via peaks and valleys in the grooves, similar but not exactly like a
>> ==============
>>phonograph record, of both sides of the discs. To play a Videodisc, you
>>inserted the caddy into the player and the platter would be extracted.
>>A keel-shaped needle with a titanium electrode layer would ride in the
>> ================== ====
>>groove with extremely light tracking force, reading the electrical
>>======
>>signal from the groove where it is decoded back into its FM state.
>>
>>Unlike a phonograph record, where physical movement (vibration) of the
>>stylus in the groove of the platter led to an audio signal, the stylus
>>in a SelectaVision player slid along the crests of the groove, at a
>> ===================================
>>constant rotational speed of 450 rpm. The varying undulations of the
>>peaks and valleys in the groove provided differing amounts of
>>capacitance between the stylus and the conductive carbon loaded PVC
>>disc. This varying capacitance was measured by the player circuitry,
>>providing an audio/video signal.
>>======
>
>
> You have proven that you can read, as well as cut and paste.

===================
He also has proven that you are wrong.................

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