Re: Apple Graphics Tablet

[David Schmenk <dschmenk@gmail.com>]

On Tuesday, June 19, 2012 1:24:09 PM UTC-7, Vladimir Ivanov wrote:
> On Tue, 19 Jun 2012, Alex Freed wrote:
> 
> > On 6/19/2012 8:37 AM, Michael J. Mahon wrote:
> >>  This was a common technique in
> >> radar scopes. (And there it's not even being used as a frequency
> >> multiplier.)
> >> 
> >
> > A bit off-topic but IMHO an interesting piece of trivia.
> > By the end of the 20th century there was a PLL in every house. Every house 
> > that had an NTSC (or PAL) TV to regenerate the color sub-carrier
> > from just 9 cycles of the "color burst" after line sync. However in the early 
> > days of NTSC they used a very high Q "LC tank" equivalent - a quartz crystal 
> > that was excited during the color burst by those 9 periods and kept in sync 
> > till the next line. Not quite perfect. Probably one of the reasons NTSC is 
> > claimed by some to stand for Never Twice [the] Same Color. :)
> 
> [OT] Speaking of oscillator excitement (kinda pun), here's something 
> interesting to read, presumably written by the late Jeff Fox:
> 
> http://www.greenarraychips.com/home/documents/pub/AP002-OSC.html
> 
> One pin oscillator. Hope you both find it interesting.


I believe this was written by Greg Bailey as he was constructing this circuit when I dropped by last summer.  Pretty cool way to get a time reference for almost nothing.

Dave...