I experience difference in signal quality which can't be attributed to weather or dish dislocation. For example, the Tube transponder on G10R is traditionally weaker than the other one with the locals, and varies considerably during evening hours. If the tps vary at the same time and same values, this could be weather related or probably because the satellite itself changing somehow the direction of the beams - I observe the latter very distinctly on AMC3, where PBS HDTV goes unwatchable like a timer every evening around 8-9 o'clock and comes back strong around midnight. But once on G10R I noticed that the Tube transponder had higher quality than the other, traditionally stronger one. That may only mean that the power/beam profile of that transponder has been changed, not anything else.