As a new Ham I was thrown head-long into building my own antennas due to a chronic lack of funds. (Finding yourself as a disabled American with four of six kids still at home will do that...) My first effort was an 80 Meter dipole followed closely by a copper pipe J-Pole for 2 Meters. Both serve well enough, but I wanted to tinker around on 17 Meters. So, what to do? Another dipole? Perhaps a fan dipole? Nah! I wanted to try something different, so...
...out to the shed to see what's gathering dust. I located a partial length of 3/4 inch copper pipe, a full stick (10ft) of 1/2 inch copper pipe, a junction box with a weatherproof cover, some copper-clad strap material,and best of all, a partial spool of old telephone wire left by the previous owner of the house. A quick trip to Lowe's for a couple of pipe fittings and an email to Universal for a few parts and coax and I was ready to work on my ground mounted vertical.
First off was the location. Once that was decided I scrounged a 6 foot section of 4x4 treated post and set it in the ground, level and plumb. Next, I used two 3/4in copper slip joints, one at the end of the 5 foot section of pipe and the other about 10 inches from the other end. These were to double the wall thickness at these points. Next, I soldered on a 3/4in -1/2in reducer to the end of the pipe. The end with the slip joint was drilled straight through both sides. At the other slip joint I drilled it in three spots and then threaded the holes with an 8-32 tap. I also drilled and tapped one hole through the reducer. Each of these holes was then fitted with an 8-32 brass screw. A cap was soldered on one end of the 1/2 inch pipe before sliding it in through the reducer and into the 3/4 inch pipe. The brass screws were then used as set screws to hold the 1/2 inch pipe in place. A couple of zips with the drill and my new vertical was mounted to the post.
Next, I fabricated a 1-1 current balun with coax and a T200-2 toroid, mounted in the junction box with brass bolt connections on one end and a SO-259 on the other. This was mounted on the 4x4 near the base of the post. Below the box I fitted a ring made from the strapping material. Next, I cut 20 foot lengths of the old 4-strand telephone wire and soldered one end to the strapping. Using a step-edger I placed the radials only slightly beneath the turf, straight as possible out from the ring. For some reason unknown to me, the previous owner had placed a ground rod just outside our sun room near the West end of the house. I decided to take advantage of this and ran a heavier wire from the ground 'ring' to the afore-mentioned ground rod. I should mention that when I set up my 'shack' (read: small table in the bedroom), I drove in an 8ft ground rod just outside the window. This is near the East end of the house and is tied to the service ground. All of my coax runs and radio grounds are tied to this rod as well. Seemed like a good idea, so I tied this newly discovered ground rod into the system as well as running yet another wire from the ring to the rod beneath our bedroom window. Now everything has a nice, common ground! Finally, I buried the coax in a straight line from the new vertical to the shack entry point keeping it no less than 6 inches below the radials. Don't know if this helps, but seemed the right thing to do. I pained an old tire and placed it around the post to keep my sons off the radials when mowing the yard. My wife plans to cover it with flowers to hide the ugly beast.
Only one thing to do now, right? Yep, I grabbed my father-in-law's analyzer and checked things out! I needed a little adjustment from my first setting, so I loosened the screws and slid the 1/2 pipe deeper into the 3/4 inch pipe, reducing the overall height.
Bingo!
One-to-1 at 18.118MHz! Next I checked the entire system from inside the shack. Same reading. So, I plugged it in to my LDG200 Pro tuner, fired up the ancient IC-751(no-A), and tried it out. The tuner barely clicked as it settled down to a no-lights match on 18.225. I keyed the mic and made a call that was promptly rewarded with a 5/7 from Maine! (Oh yeah, I'm on the Gulf Coast in Mobile, AL)
Since then I've worked many states, Canada, Austria, the islands, and Japan. Sure, my design needs work. Needs more and probably thicker radials, too. And it needs stand-offs to get it away from the treated wood, (I've got those made but have not installed them yet.) As you can see in the photo above, I painted the copper to prevent corrosion and to hide the valuable copper from would-be thieves, though I think my fully trained Great Dane guard dogs help more.
Still, you can't argue with success! Now, go make one of your own.
Bull (KK4AXX)
