When you get a cable box, with hdmi output, all you will need
to connect it to the hdtv is a hdmi cable. You won't need the
rf coaxial (screw on type) cable connected anymore. The hdmi will
take care of both hd video and audio digitally and at the highest quality. Only component or hdmi will give you hd. Monoprice.com
is highly rated here for their cables. I was able to get my 6'
hdmi cables from them for less than $5. shipped. Don't know
what you paid for yours but may want to consider them.