I’m a big fan of homebrewing antennas, especially commercially-available antennas. So, when I saw this posting on the qrptech mailing list, I asked the author, Will, KI4POV, if I could re-post it here. So, here it is, with his permission. Thanks, Will!….Dan
I recently decided that the antenna situation at the shack needed an upgrade. I’ve been using a fan dipole for a little over a year now. It worked great when I had it cut for 2 bands, 40 and 20. However as I started wanting more bands and adding more legs, the performance got progressively worse. I needed something else.
After a lot of reading and research, I kept coming back to a non-resonant doublet fed with ladder line. The low loss of ladder line seemed like that perfect solution to my issues. I looked into antennas like the St. Louis Doublet, but I didn’t have a huge roll of computer cable lying around, plus I wanted something that could potentially handle at least 100 watts in the future if I ever build an amp and go QRO.
I went to Lowe’s and after wandering around, here’s what I came up with.
I bought a 100 foot roll of 18 gauge speaker wire. my goal was a 100 foot doublet, so after splitting the two wires, this gave me 100 feet of antenna and 50 feet of feed line.
Next, I needed spacers for the ladder line portion. What I found was these bags of cable staples. They’re about $6 dollars per bag. I bought two bags worth to do the whole antenna.
These are a UV-resistant plastic spreaders that are a bit under an inch long with finishing nails through each side. They are made secure cable and wire runs in place. After pulling the two nails out, you are left with a plastic spacer that the two wires of the ladder line can be run through after drilling it out just slightly. Admittedly, pulling out all the nails and drilling all the holes took a couple of hours, but it really wasn’t to bad once I got a system going. After that, it was just a matter of sliding the spacers onto the wire, spacing them appropriately (I put one about every 4 inches), then securing them in place with some weather-resistant hot glue.
From there on out, the rest was pretty quick and easy. I made my center insulator out of a small scrap of plexiglass I had and zip-tied the wires to it through small holes I drilled. I’ve got it up around 25 or 30 feet in a tree behind our house.
I’m matching it with a t-match tuner and a tiny 1:1 current balun that I plan to show in a separate post. I was able to get a good match on 80-15 meters, and based on RBN data, I think it may be a better performer than my fan dipole. I need more time to determine how it stacks up. Band conditions have not been great the past few days.
Anyway, there’s nothing new or earth-shattering here, but just wanted to share that even with today’s prices, you can still put together a decent “all-band” antenna on a budget if you’re willing to invest a little time and effort.
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