On Nov 7, 5:13 pm, Sam Goldwasser wrote:
writes:
snip
I thought about that more after I said capacitors. The ideal
situation
would be to use a summing amplifier. Nearly as good would be
converting the chroma to current output rather than voltage using
a
transconductance amplifier and then resistively sum the chroma
and
luma. What exactly was in the home built combiner? Just a 'Y'
cord?

I've done the home-built with the capacitor, as well as with Y and
C
shorted together, or with a small resistor between them.

The IC solution like Intersel ISL59114 has the summing amp approach
along with a low pass filter on both Y and C. I wonder
if the LPF is part of the missing link here. Except that the
commercial
S-video adapter has nothing inside as far as I can tell.

None of that touches digital. HD across the LAN cables works
great
with the 'TV' computer connected DVI to a 50" DLP.

Let met get into S-video before jumping into digital.

Thanks!

--- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/

The filtering is done in the Y/R-Y/B-Y section before modulating the
subcarrier so it's just fine to sum it together.

GG