Antennas & Station Projects

The final straw was when I started noticing my signal reports on 20m were consistently a little soft. Not terrible, but guys on the other end would say things like "you're Q5 but a bit down compared to others." And I knew my antenna was decent. I'd modeled it, I'd trimmed it, the SWR at the radio was reasonable. But something felt off and I kept coming back to that sad, weathered collection of coax running from my shack window out to the fence post and up to the antenna.

So I finally ordered a 100-foot roll of LMR-400 from a supplier I trust, a couple of PL-259 connectors rated for LMR-400, and a proper weatherproofing kit with self-amalgamating tape. Total came out to around $95 which, yeah, stings a little, but honestly I should have done this from the start instead of piecing things together.

The Old Coax Was Worse Than I Thought

Before I even started installing the new stuff, I cut open the end of that old RG-8X section near the barrel connector. The braid was greenish. Not like a little tarnish — actually corroded green in spots. And the center conductor had some discoloration too. I have no idea how long that coax had been sitting outside before I got it at the hamfest, but clearly it had seen better days. Water had definitely gotten in somewhere along the run. Lesson thoroughly learned: don't buy unmarked coax at hamfests unless you're absolutely sure what you're getting and plan to test it properly.

I checked the barrel connector too and found one of the center pin connections was barely making contact. Honestly the whole thing was one good rain away from completely failing. It's a little embarrassing to admit because I know better, but sometimes you just want to get on the air and you tell yourself you'll fix it "later."

Installing the LMR-400

LMR-400 is noticeably stiffer than RG-8X, which took some getting used to. Running it around corners and through the window feedthrough required a little more patience. I used a standard oval feedthrough plate that I'd installed when I built the dipole — gave myself about 2 inches of clearance so the coax could make a gentle bend rather than a sharp one. You don't want to kink LMR-400, it doesn't forgive you the way smaller coax does.

Putting on the PL-259 connectors for LMR-400 is a little different than for smaller cable. I used the solder type connectors, not crimp. There's a specific adapter/reducer that goes with LMR-400 and you have to prep the cable really carefully — strip the jacket back the right amount, fold the braid back cleanly, make sure the center conductor is long enough but not too long. I watched probably four different YouTube videos on this before I felt confident, and I still did a practice run on a scrap piece of coax first. My first attempt was okay but the solder on the center pin wasn't quite right so I redid it. The second one came out clean.

I ran the whole 100 feet as a single unbroken piece, which was the whole point. No barrel connectors, no splices, nothing. Zip-tied it along the fence with UV-resistant ties at about 18-inch intervals and gave it a drip loop before it enters the feedthrough. Then wrapped both ends — the connector at the antenna feedpoint and the connector at the feedthrough — with self-amalgamating tape. That stuff is genuinely great. It fuses to itself and makes a completely waterproof seal. I've had regular electrical tape fail on outdoor connectors before, so I don't mess around anymore.

The Results Were Actually Kind of Exciting

First thing I did after hooking everything up was run through the bands with an antenna analyzer. SWR curves looked essentially the same as before, which was expected — the antenna didn't change. But then I got on 20m and started listening around. I noticed the noise floor seemed slightly better, which could be placebo, could be real. Hard to quantify on receive.

On transmit though, I got a few signal reports within an hour of getting back on the air and three out of four of those contacts mentioned my signal was solid. One guy in Colorado said I was "full quieting" which was really satisfying to hear because he's someone I've worked before and I know he gives honest reports. I can't say with scientific certainty exactly how many dB I recovered by fixing the feed line, but the line loss difference between beat-up RG-8X with a bad connector versus clean LMR-400 over 100 feet is probably somewhere around 1.5 to 2 dB at 14 MHz. Not earth-shattering, but real.

What I'd Do Differently

If I'm being honest, I'd have bought good coax from day one. I know LMR-400 is pricier but over a 100-foot run to an HF antenna it's worth it. The price per foot sounds scary but you're not doing this every year if you do it right the first time. I'd also invest in a proper coax seal product earlier rather than hoping electrical tape would hold up.

One other thing — I'm going to start keeping a short log of my coax runs, what type, when installed, connector type at each end, and any weatherproofing applied. Nothing fancy, just a notepad file. That way if I'm troubleshooting in two years I don't have to try to remember whether that outdoor connector was properly sealed or not.

Anyway, if you've got a gnarly feed line situation you've been ignoring, take this as your sign to deal with it. It's not glamorous work and there's no big dramatic moment like hoisting up a new antenna, but a clean feed line is kind of the foundation everything else depends on. My 40m dipole and the 20m vertical both deserve better than what I was feeding them through, and now they've got it.

Next project is probably going to be proper grounding and bonding at the station entry point. I've got a ground rod but the bonding between it and the shack panel is not great. That'll be its own adventure.

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.