I've attached an external USB drive (WD 1.5TB "Green" drive in an inexpensive black Rosewill enclosure -- looks great) to my 722.
Seems like the USB drive should be sleeping unless a) I'm actively transfering something to it or b) actively watching something stored there. Neither of these...
So, I have a Dish 1000 on the roof pointed at 110, 119 & 129. Installer came out and put another dish up pointed at 61.5, and wired it into the Dish 1000 LNB-set. Relative signal strengths are:
110 & 119: in the 80s
129: in the 40's
61.5: in the 60's
So, for example HISTORY HD channel 120 is...