Be specific with topic titles, see my edit.
As noted, please post the Panasonic model number so we can be sure about what is being recommended.
Also post the name of the cable company you will be dealing with, and your location as well.
The recommendation you got at Radio Shack is probably correct. An RF demodulator will take the cable signal and convert it to the signal like your Xbox has, and you could connect it to the set. This is the same thing a VCR will do; convert the cable signal to the type of signal the Xbox has.
But also as noted, in many areas cable companies have encrypted channels so that an RF demodulator (like in a VCR) may only receive the local channels. 'Local' channels usually consist of ABC, CBS, FOX, NBC, PBS, public service and government channels, and maybe a few others. Thus, if you use a VCR, you may only get those channels, and they would only be in standard definition.
To get the normal cable channels (2 through 70 or 99), like ESPN, USA, CNN, DISCOVERY, etc., you'll need a cable box in many cases. And, since you have an HDTV, you may as well make the best use of it by having an HD source like an HD cable box.
You could get lucky with the VCR and it may get the normal cable channels in standard definition, if the cable company is still providing them in a way the VCR can receive them. If you get a VCR, try it.
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