Do you mean when you type 852 on the tv? or the box? Because my small box does not allow me to type in 800+ channels.....

But yea, you may be able to hear the sound, but not see anything. You simply won't be able to see the HD signal with the small box's current output method (coaxial cable). I don't know if those small boxes are able to decode the HD Signal, but they would need at least component or hdmi output, which they currently don't have.

As to your questions about buying an HD box from Ebay, first of all, you will still need to sign up for "HD Service" in order to receive any HD Signal supplied by Comcast. In other words, you would need to sign up for their High Definition plan for them to 'open' up those channels 800 etc for you. Next, they would need to activate the Box to receive their programming, including on demand, messages, etc, which they only like to do with their own boxes. They are not required to activate owned, personal boxes.

In a nutshell, no.. it probably would not work.

Also, beware if the box is stolen. Once connected, it sends and receive info back to Comcast, so if it is 'flagged' as stolen (via its serial number), you may be in trouble....

I understand the frustration of paying 11 - 15/ month.. and trust me.. I also researched this extensively when I bought my LCD..... The only 'box' that you are allowed to 'own' is a TIVO Box, and even then, you would still have to lease their cable cards to receive their programming.

The only item which allowed me to 'save' on any lease is high speed internet. I bought my own Motorolla surfboard modem from Best Buy, so I do not need to lease their modem.