I did some more testing after coming home, and I wish I had a definitive, full-proof, step by step method that makes the OSSC + F3 combo work every time, but I don't. There's some randomness to the process. I can produce positive results, but I can't guarantee it will be on the first try.
Here's how I go about it:
I power on the F3, and after that I turn on the OSSC. The best working picture is always on the x3 setting. Everything else is chopped at the top, bottom, or both. Set it to x3, and if you're not getting a picture, turn off the OSSC and turn it on again. For me, it always starts with the test pattern, so I switch to 1 and boom, the picture should be there.
I did a video, but it was dark, my phone wouldn't focus and it's generally garbage. At around 1:45 you can see a clear picture, with the warping at the top of the screen, which I get a close-up on.
I've noticed that neither my TV nor my PC screen are picky about the signals, so as long as the OSSC can accept it, both of my screens will display it. If you can't get a picture on your TV doing it the way I did, maybe try a PC screen. Again, it does work, it's just process of repeating the aforementioned steps.
Also, my TV, despite being somewhat modern [modern enough to support 3D, at least], does accept RGB via SCART and it has no problems with the F3 signal. It's just not as good at scaling the picture as OSSC.
I also have a cheapo Chinese RGB to HDMI scaler. I wonder how it would deal with the F3 signal? I might try it later. The image quality leaves a lot to be desired when compared to OSSC, but you get what you pay for.
don't own a scope (yet) either by the way.
