I’ve written about the C-Pole antenna before. A friend, Mark W8FSA, and I bulit a couple of them for Field Day a couple of years ago. They’re vertical antennas, but don’t require any radials. On Field Day, we’ve found them to be good performers.
In the original article, which appeared in the April 2004 QST, the author gave dimensions for the 20m band and up. I thought this might make a good antenna for 40m, too, so I emailed the author, who graciously ran the numbers through his antenna modeling program and sent me the dimensions for a 40m C-Pole. Unfortnately, this was two years ago, and I have since changed computers and lost that email in the shuffle.
I don’t know that I’ll get around to making this antenna before this year’s Field Day (it’s only a couple of days away), but I do plan to biuld one sooner or later.