Can somebody explain transponders to me? I was trying to get some local US channels in Mexico.... they come off 119, but they are like in the 45, 89 transponders.... when I go to point dish page it only allows me to change the transponder up to 21? I get about a 75% signal down here. Any tips on getting local channels ( abx, nbc, cbs, fox, wb )????? Any help would be greatly appriciated!