Subject: Re: [stella] I really need to buy a scope From: Chris Wilkson <ecwilkso@xxxxxxx> Date: Wed, 11 May 2005 18:40:16 -0400 |
Heh....it's a DC voltage! Where by "DC" I mean it's a voltage divided form of VCC, unbuffered of course. This voltage is what controls the stage delay in the color delay chain. Due to capacitive coupling, the color pulse that propagates through the chain at 3.579545 MHz will show up on this line. And because it passes though 15 stages of delay (15 or so...I don't have my schematic in front of me) the pulse gets coupled 15 (or so) times per cycle -> 53.693175 MHz. Hmm...looks like you have 14 stages of delay in your system. Despite all of this, the delay (pin 10) input is supposed to be a DC voltage. If you actually measure it, it will look like a DC voltage with some high frequency (~50 MHz per above) noise riding on it. Plus any noise that comes from VCC. -Chris On Wed, 11 May 2005, Adam Wozniak wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Does the delay signal on the TIA (pin 10) have a frequency of about > 50.113630 MHz? > > I really need a scope. *sigh* > > - -- > adam@xxxxxxxxxxxxxxxx http://cuddlepuddle.org/~adam > KG6GZR http://cuddlepuddle.org/~adam/resume.html > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.1 (GNU/Linux) > > iD8DBQFCgZm+yvXf5Z0z5zERAmn7AJ0UrGeaWbfWGrsZDJBlACv8Ywm0wQCeLNdz > seh/ntXeDzv7XPTm01/MV7A= > =ianQ > -----END PGP SIGNATURE----- > > Archives (includes files) at http://www.biglist.com/lists/stella/archives/ > Unsub & more at http://stella.biglist.com > > Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://stella.biglist.com
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