[ARC Tech-109]

I'm not following what you're trying to do here with the amplifiers. Are you attempting to take this directly from the camera or are you using the CCU outputs? This is very important as the CCU RGB signals are conditioned to drive another 75 ohm source while the camera RGB at the connector is only a low-level of a few hundred millivolts. Another thing to consider is the monitor auto-switching over to a TTL input which is a positive going 5V at that scan rate.
Have you looked at the composite signal directly from the camera? You stated connecting it to your Ultrasharp and got the same result but it's unclear if you were in RGB or composite at this point. Got an old school CRT based monitor available to look at the composite right out of the camera?