You are pretty much correct Bojangles.
There are three Sirius satellites. They move in a figure eight pattern with the middle of the eight being centered over Iowa, the top of the eight in Canada
and the bottom over South America
. Two of them pass over the center of the eight at the same time with one traveling mostly north and the other mostly south. When they reach the center of the eight the one traveling north turns on while the one traveling south turns off at the same time.
You can see their views of Earth here...
Go to Sirius-1, Sirius-2 and Sirius-3
If you click on the thumbnail the satellites move. You can also see the old geostationary XM-1 and XM-2 satellites and see where it is local apparent noon on Earth, which gives you a sense of the satellites speed.