I agree with everything John, K8YSE, said, except that he's being too modest about what he has accomplished. AFAIK, John is one of only three living people to have made LEO DXCC, and one of only nine to have made it at all.

One thing I would add to John's comment about AO-7: the importance of using Mode A. To get the best use of this mode, a good beam antenna that covers the high end of 10 meters is highly desirable. It helps, too, if the beam is on a fairly high tower. When I was chasing DXCC on Mode A, my 3-element 10-meter monobander was mounted at about 30 feet, and Ben, W2BXA, had his beam on a 70-foot tower. He could consistently hear and work stations as much as 200 miles farther away than I could. A short session with a great-circle map will illustrate the importance of this increased range.

Why is Mode A so helpful? If your receiving system is good enough, Mode A produces ionospheric scatter that enables stations as much as 100-200 miles below the horizon to be heard, especially on CW where the weak, fluttery signals can still be copied.

Mode A seems to have become something of a lost art these days, but not for long. The US Naval Academy's HFSAT, with its 15-meter to 10-meter transponder, is coming!

73 Ray W2RS