Here I go with my second post here but I know quite a bit about Dish Network. I have been a subscriber for almost 10 years now.
Those with 2 dishes are in the eastern US. You have what is called a Dish 500 that looks at 2 different orbital locations above the equator. 110º & 119º. The second dish is aimed at the 61.5º orbital location.
110 & 119 are the main cable / satellite nets like TV Land, USA Network, CNN and more in standard definition (SD) however there are a few HD channels on there too. There are also many local LiL (local into local) SD channels on these satellites as well.
61.5 used to carry many more local channels but they have since migrated to either 110 or 119. Right now, 61.5 gives most of the national HD channels and many LiL HD channels in the east and mid-west. The LiL channels are broadcast on spot beams to save bandwidth. Thats not to say the other satellites can't do spot beams. 110 does quite a bit.
Want to see what satellite you are viewing on any given channel?
Put the channel on, press menu, then 6, 1 then 1. The number under the satellite box shows what satellite you last viewed.
International programming is being migrated (for the most part) to another satellite located at the 118.7º orbital location. The folks looking at this bird have what is called a "plus" dish. It could be a 500+, 1000+ or 1000.2+. All of these dishes see the 118 bird. These are oval shaped dishes looking at 3 different satellites. The 1000 series of dishes are only found west of the Mississippi as a general rule. Go much further west of that and that is all you will see. Except..
Dish just fired up a couple of new satellites located at 72.7º and 77º. For new subscribers in the east who go HD right from the start, they get a Dish 1000.4 that looks at these birds plus 61.5. The 3 satellites are all broadcast in MPEG-4 so all receivers on the account must be one of the new ViP series. One larger oval shaped dish with 3 LNB's does the trick here.
Well so ends lesson one of this stuff. There is much more advanced stuff to be found online like about the bigger dishes needed in AK. But that is another story. I will be back.
I stumbled on this site just today as I am looking for as much info on OTA reception as I want to compliment my Dish service with as much OTA reception possible. Dish only gives you some channels in HD. OTA gets you more plus the sub channels. I may be in a position to even get more than one DMA so that looks even better. That's why I am here.
Again, hello everyone!

layball: