Christopher's Radio Workbench

I've been licensed for about eight months now, and up until last weekend I was using one of those multi-band verticals with a tuner. It worked okay for getting started, but 40 meters was always frustrating. I could hear the big guns coming through, but getting anyone to hear me back was hit or miss. The antenna was mounted on my deck railing about 12 feet up, which I know isn't ideal, but it was what I could manage in my HOA neighborhood.

Planning the Inverted V

After reading through the antenna handbook and watching way too many YouTube videos, I settled on an inverted V as my first wire antenna project. The theory seemed straightforward enough - basically a dipole bent down at an angle to fit in a smaller space. My backyard isn't huge, maybe 120 feet deep, so the inverted V seemed like a good compromise between performance and space requirements.

For the center frequency, I aimed for 7.200 MHz since that's where I spend most of my time on 40 meters. Using the standard formula, that put my half-wave length at about 66 feet total, or 33 feet per leg. I decided to cut it a bit long and trim as needed - always easier to cut wire than to add it back.

The biggest challenge was the support structure. I don't have any really tall trees in the right spots, so I ended up buying a 33-foot telescoping fiberglass mast from one of the ham vendors online. Not cheap, but I figured it was an investment in better performance. I set it up in the corner of my backyard where it's partially hidden by some bushes.

Construction Details

For the wire itself, I used 14 AWG stranded THHN wire from the hardware store. Some folks swear by antenna wire, but from what I read, regular house wire works fine and costs a lot less. I stripped about an inch off each end and soldered them to a center insulator I made from a piece of phenolic board I had lying around from an old electronics project.

The feedpoint was the part I was most nervous about. I used a 1:1 current balun - just a simple ugly balun made with about six turns of RG-8X coiled up and secured with zip ties. I know there are fancier commercial baluns out there, but I wanted to keep the cost down and see how this simple approach worked.

Getting the antenna up was definitely a two-person job. My neighbor helped me raise the mast while I guided the coax and guy wires. I secured the mast with three guy wires at the 20-foot level, using some landscaping stakes I drove into the ground. The antenna legs slope down at about a 45-degree angle to insulators tied off to fence posts on either side of the yard.

Initial Testing and Tuning

Once everything was up, I fired up my antenna analyzer to see what I had. The initial SWR curve showed resonance at about 6.9 MHz - a bit low, as expected. I trimmed about 18 inches off each leg and checked again. Still a little low. After three more trimming sessions, I got it centered right around 7.2 MHz with an SWR of 1.3:1 at resonance.

The bandwidth was pretty good - SWR stayed under 2:1 from about 7.0 to 7.3 MHz, which covers most of where I operate. I can tune the rest of the band with my internal tuner without any problems.

What really surprised me was how much quieter the receive was compared to my vertical. That antenna picked up every bit of noise from the house electronics, LED lights, and who knows what else. The inverted V is so much cleaner on receive. I can actually hear weak signals that were completely buried in the noise before.

On-Air Results

The proof was in the pudding when I got on the air that first evening. I called CQ and immediately had three stations come back to me - all giving me 59 reports. With the vertical, I was lucky to get 57 reports and often had to repeat my call multiple times. The difference was dramatic.

Over the past few weeks, I've worked all across the US and into Canada on 40 meters with just 100 watts. Last weekend I even managed a contact with a station in Italy during a contest - something that never would have happened with my old setup. The antenna seems to have a nice low angle of radiation that's great for DX.

One thing I noticed is that the pattern seems to favor the northeast-southwest direction, which makes sense given the orientation of the wire. I can work the east and west coasts really well, but stations to the north and south sometimes seem a bit weaker. That's the trade-off with a directional antenna, but overall I'm thrilled with the performance improvement.

Lessons Learned

If I were doing this project over again, I'd probably invest in a better antenna analyzer from the start. I was borrowing one from a club member, which meant I had to do all my trimming and testing in one afternoon. Having my own would let me fine-tune things over time.

I also wish I'd planned the guy wire anchors better. I ended up with the stakes closer to the house than I'd like, and one of them is right in the middle of where my wife wants to plant flowers this spring. I may need to relocate that one before I get in trouble.

The biggest lesson though is that antennas really do make all the difference. I spent months struggling with mediocre contacts, thinking it was just the way 40 meters was. Turns out I just needed to get some wire up in the air properly. This project has me motivated to try an 80-meter dipole next - if I can figure out where to put 130 feet of wire!

For anyone thinking about their first wire antenna, I'd definitely recommend starting with an inverted V. The performance improvement over a compromise vertical was huge, and the project wasn't as intimidating as I thought it would be. Just take your time with the planning and don't be afraid to ask for help when you need it.