Forgive me for my ignorance, but this is just killing me...

I was looking at DirecTV receivers the other day at BestBuy, thinking about the upgrade from my basic receiver (RF in, composite out) to the dolby digital one. The thing that I can't get past though is that both receivers have an RF input from the dish, right? I mean, how are you supposedly able to magically pull superior video/audio from an inferior source like RF cable?

And to go one further, I have an HDTV-ready TV (sony 36XBR-400). Does an HDTV receiver also use an RF input from the dish? Does the dish for an HDTV DirecTV unit use a different type of cable to transmit the signal to the receiver?

Sorry if this is a dumb question, but I'm stumped.

One important difference.

You are thinking of analog video over cable, which looks poor to average at best.

In the DirecTV setup, the cable carries a digital signal, which can be of much higher quality. The sat receiver then decodes it and can output through a high quality analog connection like S-Video.

Basically, the cable from the dish to the receiver isn't the limiting factor in image quality.

Isn't coaxial cable able to receive data at over 30 Mbps?

Nope, RG-6 is also used. Guess what, RG-6 is also used between an OTA Anetenna and your HD/DTV receiver to transmite DTV and HD Programs, some with DD5.1!

Thanks for clearing that up... you guys rule!