On the basis of what Murrayb wrote, I went to Radio Shack and came home with 2 amp slow-blow fuses. I pulled the system apart and found a white-bodied (ceramic, I think) fuse with gold-plated ends. It is labelled T2AH 250V. T = slow blow, H I am guessing is for high current.
Amazon does sell the ceramic ones. You can get a pack of five high-current ones here for $6 plus $5 shipping. I may order a pack just to have on hand. Maybe someone can explain the advantage of the ceramic construction. It’s a pain since you can’t tell by looking if it’s blown!
I’m back in business now . But I’m now thinking about trying a high-end fuse; I was planning to do that at some point, and the one from the Shack is probably not as good as the original. People here have reported good results with Synergistic Research. I will probably call the Cable Company; they seem to have a better selection than some other places. Suggestions welcome!