Yes they are. We have two receivers that are HD, and two which are not. They all go down at the same time. We do have a new dish with (I think) 3 LNBs, and yes some of my transponders have less than 80. Time for a realignment?
We have a major tree problem, so it's mounted on a fireplace with a 10/12 pitch on the roof (two story). Not user friendly.
Simple fact that the better the dish is aligned, the less likely you are to have outages. 80's and 70's on a good day means many more outages than an install where high 90's is the norm.