That looks really good. Nice work!
If you increase the resistor between Sync and the Transistor base, that should decrease the "sync" and increase the "video". I'm partially guessing at the ciruit but it looks like a balance sort of thing. The 10K pull up gives the whole base circuit a general bias but the Spot (video) and /Sync outputs play off each other to make 3 voltage steps (White, Black, Sync). So changing either the Spot or Sync resistor will move that middle voltage (black), essentially changing the ratio of Video to Sync. To attenuate the whole signal, change the output resistors, 30/200, or what you used 47/220.
Sometimes, it pays to just use trimmer pot(s).
--- In firstname.lastname@example.org, "DougCrawford" <touchetek@...> wrote:
> My VIP had sync issues also with all my available monitors but one apparently very forgiving professional video monitor.
> I did the modification with the transistor and it now syncs with an LCD monitor which previously did not work.
> I used an MPS222A from Radio Shack instead of a 2N2222 because it was available. On the output let I also substituted 47 ohm and 220 ohm as close enough.
> Here's photos of the result and the mod, done topside fairly cleanly.
> Amplitude of the sync pulse is about 1v.
> QUESTION: What resister value change would bring reduce the amplitude slightly?