[Liudas Vasaris]"Does UpDownCross allow to input 16:9 SD and output 4:3 SD letterbox?
If it only allows convert from HD, who can do this?"
Unfortunately, the converter doesn't seem to offer this particular conversion (I have the OpenGear version, but imagine the miniconverter is the same). We take an anamorphic (16:9) SD satellite feed, and need to produce both a 720p version and a center-cut SD, and wind up using two converters: the first to upconvert the anamorphic SD to 720p (which also corrects the geometric distortion), and the second to downconvert the 720p to the center-cut SD. I would prefer to avoid passing the SD through two cards, but right now it seems unavoidable.
One thing to be aware of: depending on which interim HD format you select, the converter might not pass closed captioning. This is a known bug that they're planning to fix in an upcoming firmware revision.
Offhand I can't think of a hardware reason why the converter shouldn't be able to do the SD to SD conversion you want; perhaps they can revise their software to allow that particular combination.
Engineering Project Manager
Newport Television, Northeast