I was able to steal some time this weekend to construct the 20m shortened vertical I’d been designing using 4Nec2. It didn’t turn out quite like I was planning, but it’s good nevertheless. I used half-inch-dia aluminum tubing and a section of an MFJ prewound coil to build it, and I used construction techniques stolen largely from AD5X’s portable vertical design. The main differences between his design and my implementation are

  1. I used a single 6-ft aluminum tubing section on the bottom instead of constructing multiple smaller sections.
  2. I used another single 6-ft aluminum tubing section above the coil instead of the telescoping antenna.
  3. My coil used only 3″ or so of the MFJ prewound coil, and I used a length of nylon rod instead of wooden dowel. Mine is also tappable with an alligator clip.
  4. My antenna has a 30″ brass rod forming a tee at the top of the radiating element, as a capacity hat.

Continue reading

Last week I told you about how I’d gotten a nice free antenna modeling package for Windows called 4Nec2 to run in Linux using Wine. Since then, I’ve been able to create a few models and run them, and I gotta say I’m really impressed with the capabilities of 4Nec2. I doubt I’ve even scratched the surface of what’s possible, but it’s worked flawlessly for me so far. I have experienced a few minor glitches that are the result of running under Wine, but those are minor and easily worked around. Mostly, those glitches are associated with trying to run the help file, and I haven’t spent any time trying to fix those things. No big deal, as far as I’m concerned, and certainly not a knock on 4Nec2 itself.

Continue reading

I’ve already written a couple of times about my efforts to use antenna modeling software to design a new antenna for the back yard. My original plan for a four-band vertical is perhaps overly-ambitious, so I may scale back to designing some sort of short vertical for 20m that’s both sturdy enough and inconspicuous enough to leave erected in the back yard for more than a few hours at a time. In the mean time, I continue to use Phil Salas’ ultimate portable vertical when I get the chance. But I digress.

Since I launched this little project, I managed to sidetrack myself by converting completely over from Windows XP to Ubuntu Linux. If you know me (or perhaps you can detect this from my blog entries), you know that I tend to be thinking about several different ideas at the same time, and this often results in my making little or no progress on any of them because I can’t focus on any single idea for very long. Maybe it’s an attention span deficit or something. And such appears to be the case with my antenna project. But while I continue to enjoy learning about the wonders of Linux (and I confess I’m thoroughly enjoying Ubuntu so far), I figured it was time to get back to antenna designing.

Continue reading

This weekend I took the plunge big-time, completely replacing my Windows XP desktop installation with Ubuntu 7.10. Being a ham, my computer setup is a little more complex than normal because I use my computer to control my ham radio (an ICOM IC706MKIIG) for contesting and for making contacts in digital modes. I use a West Mountain Radio Rigblaster Plug & Play USB interface to control my radio and for sound card and keying interfacing. So, it was with a little trepidation that I abandoned the world of Windows for Ubuntu.

Continue reading

Well, in a moment of possible lunacy this weekend, I blew away the remaining vestiges of Windows XP on my two PCs and went over to the Ubuntu side. I’d already been running Ubuntu exclusively on my notebook and using that as my day-to-day system for a couple of weeks now. But I had still hung on to my Windows XP desktop system (nothing special–a 1.5GHz AMD Athlon with about 750 MB of RAM and a 40GB HD), in case I needed to go back.

Continue reading

(Updated 20 Jan 2008–added “sudo ndiswrapper -m” step, and added a note about manual configuration)

(Updated again on 5 Mar 2008–clarified some steps in the instructions)

You can probably figure this out for yourself if you search the web diligently. In fact, here’s a nice overview. Here’s my method for getting my WPC54G wireless PC card working with WPA wireless security under Ubuntu Gutsy Gibbon (7.10). The computer I’m installing on is an old IBM T23.

It’s worth noting a few things up front. First, My WPC54G is labeled “Ver. 2” on the back. Many Linksys adapters come in multiple versions, and different versions tend to use different chipsets internally, so instructions for getting one version to work may not work for a different version.

Second, in my case the WPC54G worked out of the box with Ubuntu 7.10, until I tried to use WPA for my wireless encryption. Once I turned that on, the notebook basically turned into a brick. The solution, it turns out, is to use the WPC54G via ndiswrapper. It’s not as hard as it sounds or looks.

Continue reading

Anyone who’s been reading this blog (and I can probably count that number on one hand) knows that I’ve been thinking about a new (to me) antenna design. Being in a covenant-restricted neighborhood, I can’t erect a permanent obvious-looking antenna. But the neighborhood covenants are not extremely restrictive, I have nice neighbors, and there doesn’t appear to be any actual HOA that actively searches for covenant violations, so I figure I can get away with an antenna with a reasonably small visual footprint that I only put up when I want to play radio. To top things off, I have no trees or other readily available antenna supports, so whatever I end up using must be free-standing. The obvious choice, at least to me, is a vertical antenna.

Continue reading