i just picked up a pansat 250sm and i'm trying to get it to work but the only dish i have is a direct tv dual lnb dish so far i have a good signal but can not get any channels or figure out how to set it to work with this dish please help me :rant:
You need a linear lnbf, and possibly a bigger dish (you didn't say which DTV you have-some of them can be fabricated on to work with some stronger fta signals). Best bet would be a new 1m dish made for free to air, most pay-tv dishes are too small to work reliably and they usually have only circular lnbf for the stronger, pay-tv signals. Linear ku band, which is where most of the free to air comes from, is weaker and takes a bigger dish+linear lnbf to receive. Or, you can look around the area, check craigslist, etc for a no-longer-used primestar dish, there's still some of those to be had, usually just for taking out of somebody's yard. They are very nice fta dishes and the lnbf most always is ok and working.
Are you sure it is a dual LNB DIRECTV dish (not Dish Network)? If so, you have a rare bird there. These were known as Phase II dishes, and there aren't many of them around. As Turbosat said, for FTA you'll need a 30" or larger dish for reliable reception, as well as a linear FSS Ku-Band LNBF. Or you can use the dish you have, as Classicsat suggested, and aim it at 119w for some freebies from Dish Network (NASA, ION, and a few "banner" channels). If you do that, you'll want to set your receiver up for a "Standard" or "Single" LNB, L.O. 11250, 22k and DiSEqC to "OFF".