I own a 480p set and recently purchased an SIR-T150 tuner so as to get OTA digital tv in Chicago. First off, the digital broadcasts, even the non-hd broadcasts, are awesome, seeming to rival anamorphic dvd's at times. The problem is that I can't tell when to put my tv into 16x9 mode. For instance, on West Wing last night, with my TV in 16x9 mode, tuner in 16x9 mode full format I received a great looking letterboxed image that appeared to look approximately 2.35:1. But on regular broadcast television the letterboxing is more like 1.85:1. My image did not appeared to be compressed. Are some non-HD digital broadcasts sent in widescreen then? Given my equipment, what is a surefire way to confirm the approproate screen format to use? Thanks in advance.