How many PBS stations use the national feed of PBS instead of programming their own schedule for their stations? I was surprised to learn that WYIN TV is doing just that with PSIP 56.3 & 56.4 (56.4 being a simulcast of 56.3). They were simulcasting the main channel on 56.2-56.4, but recently started airing the national PBS service on 56.3 & 56.4 part of the day. I don't know when they started doing this, but noticed it yesterday. They do program their own station on 56.1 (also simulcasting 56.1 on 56.2, at least for now), but I don't exactly know why they're carrying the national PBS along side their own programming. I would think that maybe they might add PBS World since WTTW took a pass on that to program WTTW Prime (WTTW's 24 hour Primetime program channel). WYIN used to carry Create, but that eventually went to WTTW. I wonder if WYIN is airing the national PBS to simply add another part of the PBS service to their subchannels. I will say that they don't have the bandwidth to handle this extra channel. It wasn't an issue when all 4 channels were airing the same thing, but is a problem now. 56.1 & 56.2 are fine, but 56.3 & 56.4 when airing the national PBS freeze up at times. Supposedly, WYIN is running 2 channels at 720p each.