Can I use the Old Bell Express Receivers 2700 and 4100 with a HD 6100 Bell Express Receiver on the same Dish at the same time too or do I need another dish for HD.
I run two 2700's, a 3100, and a 6100 receiver off the same dish, so yes it's possible. You will need a switch, SW44 may be the easiest, but there are cheaper ways of doing it, especially if you already have a switch like an SW21 or an SW24.