I just bought an HDTV ready projection tv (no hdtv receiver). I have digital cable, and the digital channels look great, but the network channels not so much. The cable goes from the wall to the cable box to the Tivo to the tv. Does it matter what kind of connectors I use (coax, standard av, etc.)? Any other advice on getting the picture to look better?
Nuveena
Nuveena congrats on your first post!
You might get a better response to this in GQ, but maybe IMHO will do the job.
Since you are using what’s coming out of the wall (ie cable) as the source I don’t think there’s much chance of improving the picture.
Ideally you’d like to minimize the number of times the signal is converted from digital to analog and back. I think that the cable box decodes the digital signal and the coax output from it is now analog. What the TiVo does I don’t know, but I doubt if it actually degrades the signal.
Could it be that the networks are giving the cable company a lousy analog signal to start with? Do they have a digital version of the networks available? If so, it would be stuck up in the higher numbers.
Welcome to SDMB, Nuveena! 
Wasn’t there a hair product by that name? 
Yes, the connection type matters a great deal. The problem is that you may not have many options. Whatever outputs your cable box provides is what you’re stuck with. If it offers multiple choices, go with the best it offers that your set accepts. IIRC, the typical choices, from best to worst, are; optical digital, S-Video, Component Video, RGB, and coax. It’s unlikely you’ll have more than two options on a cable box, unless you bought your own. Connection types are even more important when you’re talking about hooking up a DVD player, but the same rules apply.
I agree with pilot141. It’s unlikely your Tivo is degrading the signal, but the fewer domain conversions, the better. You could try bypassing everything, and connecting the cable straight into the TV, if it accepts it. If not, just eliminate the Tivo box, and see if the network channels clear up. If they don’t, there’s nothing you can do, except complain to the cable company. Sometimes, that actually helps. But, don’t count on it, too much.
More likely, your local cable provider is being spiteful because they’re forced to carry the local network affiliates, and they don’t make any money on those channels. So, they tend to compress those signals as much as they can get away with, to reserve bandwidth for the pay channels.
I’ve heard of people who’ve had luck with the following phrase, when talking to their cable company:
“If you can’t make this look better, I’m going to switch to DirecTV.”
-lv
Thanks for the help. Going without Tivo is not an option; I’m completely addicted. From the cable box to the Tivo, I can either use coax or standard (red, white, yellow) av cables. From the Tivo to the TV, I also have the option of S-video.
Since you mention it, I’m also going to be hooking up a DVD player. The owner’s manual for the TV says for a good picture use the standard yellow cable, for a better picture use S-video and for the best picture use component video connectors (red, green, blue). Do you recommend the S-video over the component video?
Also, are there different qualities of coax cable, or are they pretty much the same?
I didn’t mean to leave it out of the system forever. That was just to test whether the Tivo box was degrading the signal.
Cable-to-Tivo - separate cables, not coax. Tivo-to-TV - S-Video
Oops! I got that backwards, in my last post. :smack: Sorry, I was tired. No, Component Video is better than S-Video. Follow the manual’s advice.
There are, but the differences are pretty minor. One upgrade that does pay for itself is gold-plated connectors. They don’t oxidize like the cheap ones, and oxidation buildup can degrade the signal. You can always clean the oxidation off, periodically, but who wants to do that?
But, do buy the best quality connectors you can find/afford for the other connections.