Originally Posted by JJkizak
Last night I rescanned and 56.1, 56.2, 56.3 came in and blew away 43.1, 43.2. I also now get the 56 channels on 43.1 plus there are three more channels with weird numbers, 43.197 etc.
Tropospheric refraction was happening that day and your set scanned WTVS in Detroit (RF channel 43 and virtual channel 56 - and, yes, before analog shutoff, WTVS-DT and WUAB analog could make each other miserable when "trop" was in).
56.1 is the main PBS channel for the Detroit area
56.2 carries an alternative PBS program stream that is timeshifted (if you don't like the program on 56.1, try 56.2). This is a rare stream that is in widescreen SD 480i - it appears as a squished square on some widescreen sets unless the aspect ratio is reset.
56.3 is the "Create" channel seen on nearly every PBS affiliate.
43.197 is part of this same stream - in carries "update TV" data that TV sets cannot decode.