The Dish Network User's Resource
I just noticed a weird little logo popping in and out on the screen. The best way to describe it is that it looks like a “sun” or maybe a “comet.” It only last for a second, but it seems to happen every few seconds. Anybody else seen this or at least have an explanation as to what it is?
This is an indicator that the anti-multipath hardware is doing its job at the distant end of the locals backhaul. It is not in your receiver.
This occurs when there is some signal degradation in the off the air reception in the originating city. Dish probably hasn't disabled it because it's the only way they have back at the uplink center to help analyze PQ problems caused by off air reception.
For more information on the hardware that does this, see: http://www.intelvideo.com/vp50.asp (dead link)
Update, 12/07: The logo has not been seen for several years. This EKB page remains as a historical note.