See if there's a 480i/p mode versus the upscaling mode typically used for 1080i CRT RPTVs. Simply deinterlacing 480i (SD) doesn't emphasize cable-signal noise, etc. as much as upscaling 480i to 540p, 960i, etc. Analog-only SD cable signals seem to appear worse than SD delivered digitally. Some cable systems have a mix of SD delivered both digitally (cable's QAM) and as NTSC (analog). Other systems deliver all channels digitally, but retain some analog delivery.
A direct connection to the Mit's NTSC tuner, through a 1-GHz splitter, might provide better SD for the non-scrambled channels. Here, via Time Warner Cable, used to view SD via S-video because older converters only put out poorly upconverted (1080i) SD, even though it was all digitally delivered. The newer SA8300HD does a much better 1080i upconversion, so now I view everything via 1080i YPbPr. Separate picture controls handle SD and HD. My CRT RPTV doesn't take DVI/HDMI, and many report seeing equal PQ from component versus digital STB outputs, or worse images with DVI/HDMI, which is more suitable for all-digital displays such as plasmas, DLPs, and some LCoS. -- John