Hi,
I'm looking at various new TVs etc. and it seems like the TV will take component/RGB and the DVR etc can output RGB (component on some but not all). However, scart rgb uses the composite for the sync and the TV expects sync on green. So I can either buy a hugely expensive converter or knock my own up.
So I think all I need is a LM1881 to get the sync from the composite. Since the LM1881 is high input impedance and I'm not using the composite then a lash up should not feed back significant noise to the RGB lines. The LM1881 sync output is rail so it could be 5 or 12V. I only need 0.3V so a 1K2 or 3K for 12V from sync output to G should give me the right sync. The high impedance will attenuate any noise on signal as well as not disturbing the impedance.
Sounds too simple - am I missing something?