AAAAAAARRRRRRGGGGGGGHHHHHHH!!!!!!!!!!!

A friend of mine recently got me interested in building the C-Pole antenna as described in the April 2004 QST. It’s a variation on the vertical dipole, and needs no radials, even though the vertical length is less than a quarter wavelength. One drawback, though, is that it needs a balun.

The author experiemented with two different types of baluns. The first type–33 feet of RG-58 coax on a 2-in diameter PVC pipe–seems cumbersome and lossy (14%). The second option–14 turns of RG-174 coax–on a ferrite core seems the better choice, except that I don’t have any RG-174. Nor do I have the ferrite cores the author suggests–an FT-240-61 for the 20m antenna and an FT-240-67 for the 17, 15, 12, and 10 m antennas.

No problem, I think, I’ll just buy a couple of them. Well, for whatever reason, neither Universal Radio or alltronics.com carries the FT-240-67, although they have a great selection of other types. They do have the FT-240-61, but it costs ten bucks.

So, I start thinking about alternatives. Well, it just so happens that a long time ago I bought an Amidon balun kit (which consists of a T-200-2 core and 12 feet of #14 enamel wire). “Perfect, I think,”this thing’s been languishing in my junk box for at least 15 years. Now I can use it.”

The balun is just a 1:1 balun, I reason, so why don’t I just wind it up and see how it works? I’m actually getting a little excited about this, thinking to myself that this will be a pretty cool learning experience. I go down to the shack, cut the wires, and then reach for the core on the workbench. Unfortunately, it slips from my fingers, and when it hits the cold, concrete floor, it snaps in two. AAAAAAARRRRRRGGGGGGGHHHHHHH!!!!!!!!!!!

It was certainly a learning experience, although not the one I wanted to learn. I learned that ferrite cores are very brittle, and to be more careful next time.

Tomorrow, I’ll have wander down to local radio shop and see if they happen to have another core. I think I’ve seen the balun kits in there, but am not sure if he will have just the core. In the meantime, I’ve e-mailed the author of the antenna article to see what he thinks about using this balun kit instead of one of his designs. In the article, he hints that he thinks using closely-spaced 14-ga. wire on a ferrite core should be less lossy than the coax version, but that he hadn’t tried it.