I assume you mean composite cable since component cables would indicate an HD box. Nevertheless, there would likely be little/no difference. Perhaps S-video if the SD STB has it?Will using an HD box with an HDMI cable improve the SD signal quality over component cables from a regular digital box?
I suggest you call ATN and see what they have to say, I am not sure if they even know much about HDTV?! I recall at a recent CRTC hearing (I believe it was for specialty channels & BDU's) they were asked a question about either on demand or HD (I can't recall which) and they really had no clue what the CRTC commissioner was talking about. They also stated that their customers do not know much about these technologies are not interested in them. Clearly that is false, I am sure many of their subscribers are aware of and know what high definition television is- they probably just downplayed things because they don't want to spend the money required to launch an HD feed.I am surprised ATN has no HD offering, as Zee (with whom they are partnered) appears to have a couple of HD channels.