I have really arthritic hands. So, last night, I was thinking, “Winding a toroid, how hard can it be?”
Turns out it can be very hard. My hands still ache 🙂 Anyway, here is the one I wound.
Those familiar with the EARCHI End-Fed Matchbox may recognize this — because that’s what it’s for. A 9:1 UNUN that goes in a little box with some hardware, and you attach about 35′ of #18 insulated wire and a counterpoise to get an “emergency” antenna that does 40-6 (with a tuner) and handles 100W. I bought one of these assembled in 2013 as a “get on the air” antenna and it worked pretty well when I strung it as a vertical from a Jackite kite pole. If I’d known then what I know now, I would also have added a counterpoise, but there was no ground terminal on the one I bought that would have made that obvious. Apparently they changed the design after I bought mine, because now it does call for a separate counterpoise ground terminal.
I had idly considered buying another one for my shack-in-a-box, but EARCHI no longer sells the assembled antennas. So I hammed up and bought the parts to make my own. They are, absent arthritis, pretty doggone easy to build.