Building a Portable HF Antenna for DXing in Under 2 Hours

I built this antenna while my coffee was still warm, and an hour later I was working a station in Slovenia from a picnic table. If you’ve ever felt like portable HF antennas are either too expensive, too flimsy, or too complicated to build on a Saturday morning, I get it. I’ve been there. On Radio Waves, I always try to share projects that get you on the air fast without needing an engineering degree or a bottomless wallet. This one is my favorite.

Why This Antenna Works So Well for Portable DXing

Most portable ops overthink the antenna. You don’t need a multi-element yagi strapped to your backpack. A simple resonant vertical with a good ground plane will hear and be heard across continents. The design I’m going to walk you through is essentially a quarter-wave vertical for 20 meters, but you can easily scale it for 17, 15, or even 10 meters. It breaks down to less than two feet, weighs almost nothing, and sets up in the time it takes to unroll a coax cable.

At Radio Waves, I’ve tried magnetic loops, end-fed half-waves, and even a Buddipole clone. I keep coming back to this vertical because it’s repeatable, cheap, and surprisingly quiet on receive when you’re far from urban noise. The secret is in the radial system, which we’ll build right into the design.

What You’ll Need (All Under $50 Total)

You can get everything at a local hardware store or from your junk box. I’ll list the exact parts I used, but substitutions are encouraged.

• A 17-foot telescopic fishing pole (the kind that collapses to about 20 inches). I bought mine for $12.
• 16 to 18 feet of insulated stranded wire, 14 or 16 gauge. Speaker wire works great.
• A small BNC binding post adapter or a chassis-mount SO-239 connector with a 3/8-inch stud.
• Three 10-foot lengths of wire for radials. Any scrap wire will do.
• A small plastic project box or a simple cutting board to mount the connector.
• A few zip ties, electrical tape, and a small stake or tent peg.
• Coax with BNC connectors (RG-58 is fine).
• An antenna analyzer or your radio’s SWR meter. You’ll need this to trim.

Step 1: Build the Feedpoint in 20 Minutes

This is the only part that requires a tiny bit of assembly, and it’s the heart of the whole system. I call it the “pocket matchbox” on Radio Waves. Grab your project box or cutting board. Drill a hole in the center just big enough for your SO-239 or binding post. Mount the connector tightly. If you’re using an SO-239 with a stud, you’ll have a solder lug for the vertical element and a wing nut for the radials. If you’re using a binding post, you’ll have two terminals: one for the antenna wire, one for the radials.

Now take your 17-foot wire for the vertical element. Strip about half an inch, solder it to the center pin of the SO-239 or attach it to the red terminal. That’s it. The box will sit at the base of the pole, so don’t worry about strain relief yet. Just make sure the connection is solid.

Step 2: Attach the Wire to the Pole

Extend the telescopic pole completely. Don’t let the sections twist apart; gently pull them out. Now, starting at the tip, run your wire along the pole. I use small zip ties every 12 inches or so, just tight enough to hold the wire without crushing the pole. Leave about two feet of wire dangling at the base for connecting to the feedpoint. The wire should follow the pole straight up. At the very tip, I fold the wire over and secure it with a tiny piece of heat shrink or electrical tape so it doesn’t slip back.

This is the part where people get nervous about the wire length. Don’t stress. We’ll trim it later. For 20 meters, a quarter wave is about 16.5 feet. Start with 17 feet of wire and you’ll have plenty to trim. The pole itself is non-conductive, so it’s just a support.

Step 3: The Radial System That Saves Your DX

A vertical without radials is a dummy load with a nice view. I’ve learned this the hard way, chasing DX on a beach with poor ground. Your three 10-foot radials are going to lay on the ground, and they don’t need to be perfectly tuned. Attach all three to the ground side of your feedpoint, either by crimping ring terminals and connecting them to the wing nut or by twisting them together and securing them to the black terminal.

When you set up, fan the radials out like a tripod. They don’t have to be straight. They can follow the shape of the ground. If you’re on a concrete pad, don’t worry, just spread them as best you can. The goal is to give the RF something to push against. On Radio Waves, I’ve written about this before: even two radials cut roughly to 10 feet will transform your signal. I’ve worked Japan with exactly this setup while sitting on a park bench.

Step 4: Tune It in Under 15 Minutes

This is the step that feels like magic, but it’s just careful trimming. Connect your coax from the feedpoint to your antenna analyzer or radio. Extend the pole, spread the radials, and take a reading. If you’re targeting the 20-meter phone band, you want the lowest SWR around 14.200 MHz. The initial reading will almost certainly be too low in frequency, meaning the wire is a bit long. That’s perfect.

Lower the pole, trim an inch or two from the top of the wire, and reattach it to the tip. Test again. Repeat until the dip is exactly where you want it. This took me 12 minutes the first time I did it, and now I can tune a new band in 5. The key is small cuts. Once you hit the sweet spot, mark the wire with a permanent marker so you can return to that length in the future.

Step 5: Deploying in the Field Like a Pro

The whole antenna rolls up into a bundle the size of a water bottle. I keep it in a drawstring bag along with the radials and a 25-foot coax jumper. When you arrive at your spot, stake the base of the pole into the ground with a tent peg or just lean it against a bush. Connect the feedpoint, attach the coax, spread the radials, and you’re on the air in under three minutes.

One trick I’ve shared on Radio Waves is to use a small carabiner at the top of the pole to hang the wire if you want to experiment with an inverted-L configuration. That’s a whole other article, but the same feedpoint works for it.

Real Results from the Field

I’ve used this antenna to work 40 countries on 20 meters alone. My best moment was activating a local state park with a 5-watt radio and having a station in Finland come back to my CQ on the first call. The antenna was leaning against a picnic table, radials tangled in the grass, and it still performed beautifully.

You don’t need a tower. You don’t need expensive gear. You need a resonant wire, a good ground plane, and a little time to trim. That’s the spirit of Radio Waves, and I hope this build gets you out there chasing DX sooner than you thought possible.