Thanks, have mostly memorized that, and built one of his HF chokes before he redid his cookbook. I used 3/8" superflex Helixax and ran it through three sets of epoxied together stacks of ferrittes. It's at the base of a 43' wire that goes up the side of my house. Between the choke and the wire is a switchable matching coil for 80 and 160 meters. There are radials. I have one of those cheap Chinese VNAs on order and may very well sweep the common-mode side of that whole lashup to see how the chokes worked out as built. The idea is that it's supposed to cover everything from 160 to 15 meters. I have local antenna ordinances and a limited amount of space so it's probably the best I can do for those bands. I still have to put some insulators on my roof before I can use it, quite possibly a project for tomorrow morning.