I have a KD30XS955 and am using a cable card for my HD broadcasts, but I have a splitter so both my VCR and TV can both recieve cable. I tested it using the splitter and without it and noticed the picture was a bit better, but that could be just my mind. Do splitters really cut the bandwidth? If so, are there any good splitters that dont? Thanks.
A splitter will have no effect whatever on digital signals so long as the signals are still strong enough after being split to be be properly decoded. If it gets to weak you will get major problems like sound and picture dropouts not small changes in the picture.
With all this being said, it is still best if a dedicated line is run for incoming OTA signals. An uncut line is preferred. But, if that is too difficult, try a split and see what happens. A pre-amp can probably help here. Bottom line, as long as you are getting 95-100 on a signal strength meter, you should be ok. Whether the meter reads 95 or 100, the image quality on the dsiplay will appear the same.