[sdiy] Combining two of my favorite hobbies

[Gene Stopp]

Re: monitor stuff - since I got the same results with both RF-modulated
composite video over coax AND S-video over S-video cable, combined with the
fact that the original CRT-based tv worked just fine, made me look
elsewhere. On the 760 video card there is a 4.43Mhz crystal near the Toshiba
CXA1145M composite video modulator chip, and no 3.579Mhz crystal anywhere to
be seen (although there is a 14.318Mhz crystal by the Ricoh RGB chip, divide
by 4 is 3.570Mhz, but it's almost on the other side of the PCB). After much
googling I discovered that there are apparently two standards for NTSC - one
is "NTSC/3.58" and the other is "NTSC/4.43". The common standard for NTSC is
a color burst frequency of 3.579Mhz and PAL is 4.43Mhz.

So I wonder if the thing is using NTSC/4.43 and the LCD tv doesn't like
that, but the CRT tv does. I have a plan to examine the PCB further to see
if my idea is correct. If so, I can maybe swap out the crystal as an
experiment.

I did try the PAL/NTSC hardware switch on the card (made it worse set to
PAL) but then Ingo pointed out the hidden software option (which is not in
the manual, BTW, thanks Ingo!). Another thing to try...

Anybody who finds technical flaws in the above ramblings please feel free to
chime in - this is definitely not an area that I have any experience in!!!

- Gene



-----Original Message-----
From: Magnus Danielson [mailto:cfmd at bredband.net]
Sent: Wednesday, September 22, 2004 4:38 AM
To: gene at ixiacom.com
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Combining two of my favorite hobbies


From: Gene Stopp <gene at ixiacom.com>
Subject: [sdiy] Combining two of my favorite hobbies
Date: Wed, 22 Sep 2004 11:48:33 -0700
Message-ID: <BCD0C6AAF20CEA41903A1284F549D6170B5360 at ixca-ex1.ixiacom.com>

Gene,

> > http://www.seattlerobotics.org/encoder/apr98/breadbrd.html

Haven't your wife told you that you need to cut down on the DIY activities
so
you can keep a decent weigth?

Now, how did that monitor cable TDR buissness go?

Cheers,
Magnus - who's inventions also includes an odd form of bread :9