I have a DISH PVR connected to two TVs. TV1 is in the same physical location as the PVR, TV2 is in another room upstairs. I currently use two DISH remotes to control the two TVs respectively. I'm pretty sure I can use harmony 520 to control TV1 because it's sitting next to the PVR.

Now, my first questions is: can I use the harmony 520 to control TV2? My guess is NO, because of the distance between TV2 and the PVR. The existing DISH remote for TV2, I belive, uses RF signal to communicate with the PVR upstairs, and 520 doesn't support RF(?).

My second question is: if 520 can't do the job, will 880 do it?

I'm pretty new to the harmony remotes and searched around this forum, but failed to find a good answer to my questions.
So any advices will be highly appreciated!

You can use the 520 or 880 or 6xx but you'll need an IR repeater to transmit the signal from TV2 back to the Dish PVR. Alternately you can use the 890 which has built in RF capability but there have been many problems getting those to work. You might have to stick with the Dish remote for TV2.