From the Echostar Knowledge Base:
Can I use an old 18" Dish to get 105° or 121° satellites?
The short answer is: "No. You can't."
The satellites at 105° (AMC2 and soon AMC15) transmit at a much lower signal strength than the DBS satellites. This means that in order to get a good reliable signal, a 30" dish is really desirable. An 18" or 20" dish will not be able to "pull in" a strong signal to be usable if it can get one at all!
The "medium power" used by these satellites is by design. Not just design of the satellites, but by international treaty. There are only so many slots available in the one orbit possible for geostationary satellites (they appear to stay in one spot in the sky) at 22,300 miles above the equator. We in the states have to share with the rest of the countries in the western hemisphere. Simply "cranking up" the power on these satellites, even if it were possible, could interfere with adjacent satellites aimed at other parts of the world.
Can I use the Dish or DirecTV LNB on a big dish to get 105° or 121°?
Again, the answer is no. The LNB that comes with Dish and DirecTV "standard" dishes (18", Dish 500, or Direct's three slot dish) are designed to pick up the DBS frequencies used at 110° and 119°. They cannot pick up the FSS frequencies that 105° and 121° use. Think of it like trying to pick up an AM radio station with an FM radio. It just won't work.
Can I get an old Primestar Dish and LNB and use it?
Yes! Dish is using a very similar system and it is compatible with the old Primestar standard LNB and Dish.
See ya
Tony
