I have an iMac 24" and recently connected a Pinnacle 800e USB stick to use with my Comcast cable. I connected the coaxial cable directly to the USB stick and was able to get the analog (1-99) channels. Since the Pinnacle can also receive HD broadcasts I connected the included antenna and was able to view the over-the-air HD channels. (I've been watching the Olympics). The over the air signal is not the greatest. I cannot get all the ones available (I can only see Fox and NBC, and maybe if I am lucky ABC). I wanted to see the other channel, plus cable channels like ESPN, so I ordered a HD Receiver from Comcast, but now am wondering if I can even connect the Comcast receiver (Motorola HD DCT-6200, I think) to the Pinnacle USB stick. There is a coaxial connector on the receiver, but would it send HD? I wanted to sample the HD on my iMac, before deciding to get a HDTV to see if the HD programming was worth the extra costs. Will I be able to use a Comcast HD receiver on a Pinnacle USB stick connected to my iMac or will I need to cancel the installation order? Any help or suggestions would be appreciated.