Here’s some tests with my 1040STe.
All of these are through VGA (since I don’t know how to get to high resolution through the SCART)
First picture is with the Best Electronics cable to VGA to OSSC;
Second Picture is with the Ube Switch; http://www.atari-forum.com/viewtopic.php?t=30521
Notice that the second picture (while still having lines through it) is much clearer. Not sure if this is because it’s just this tiny box between it and the OSSC, and the other one has a female VGA end so it needs a VGA cable in between or the OSSC is just that nice?
Both of them look to need to be adjusted, the lines usually represent the hsync/vsync being off a bit. I noticed there are settings in OSSC for this, but I didn’t spend much time yet figuring them out.
Last image is the frequencies that are being used.