Thank you! Do you think I can convince the installer to try the hopper with existing cable? Is he right that the hopper could burn up the cable if it is not rated for 75 ohms? He said "it may work for a while but will eventually burn up." Seemed odd.
No. He's flat wrong. The cable won't "burn up". This is what will happen. If the cable is not rated for the full 3GHz, you will have greater attenuation at the higher frequencies. For instance, if its only rated for 2.2 GHz, anything over 2200 MHz will attenuate faster than the lower frequencies. You will have a greater chance of experiencing signal loss. Now, this is the fun part. Just because it's not rated for 3 GHz, doesn't mean it won't pass 3 GHz. It just means that's all the tested it to. tl;dr If it's not labeled rated for 3 GHz, it's a crap shoot how well it will work. But no, it will by no means "burn up".