The Signal Lab

The Other Half of Your Antenna Has to Go Somewhere

Here is a question that shows up every week, in every ham group, forever. An operator has an HOA-compliant flagpole. He wants to run a wire up it -- straight up, discreet, maybe a 49:1 at the base. His SWR tunes to nearly 1:1. And nobody comes back to his CQ.

The replies are always the same, and they are always circling one thing without naming it: radials, counterpoise, ground rods, a “well-hidden counterpoise.” Everyone is trying to solve the same problem. So let us name it.

Every one of those suggestions is trying to build the missing half of the antenna.

An Antenna Is a Circuit, and a Circuit Has Two Halves

RF current does not flow into a wire and vanish. It flows out one terminal of your feedline and back into the other, and the antenna is the loop it travels. A dipole gives that current two legs of wire. A classic quarter-wave vertical gives it one leg of wire and asks the earth to be the second leg -- which is why the textbook version sits on dozens of buried radials.

A single wire up a flagpole with nothing on the other side of the feedpoint is half an antenna. The current still finds a return path, because it must. It finds it through your coax shield, your ground rod, your house wiring, the damp dirt under the lawn -- whatever is available. The question is never whether there is a second half. The question is whether you built it on purpose or the current improvised one out of whatever it could reach.

Why the Yard Was Never Going to Hold the Other Half

The improvised return path is not free. It is resistive, and here is where the physics gets specific.

Efficiency is radiation resistance divided by radiation resistance plus loss -- R_r / (R_r + R_loss). John Kraus, W8JK, established in Antennas that radiation resistance falls with the square of length in wavelengths. Robert J. Zavrel Jr., W7SX, works the same ground in Antenna Physics: An Introduction (ARRL). A 25-foot wire is a respectable fraction of a wavelength on 10 meters and a small one on 80 -- so R_r collapses on the low bands while the loss keeps its share. The band where you most need every ohm to radiate is the band where the improvised earth return eats the biggest fraction of your power as heat.

And the earth is genuinely lossy. Rudy Severns, N6LF, measured it in his QEX ground-system series -- measured, not modeled. His work is why the serious quarter-wave crowd buries thirty and sixty radials: copper in the dirt reduces earth loss. It works. It is also exactly the thing an HOA yard cannot hold. You cannot trench sixty radials through a lawn the association mows, and a “well-hidden counterpoise” is a polite name for a small, compromised one.

One more thing nobody in those threads mentions: if the flagpole is aluminum, a wire taped up the outside of it is not a wire antenna. It is a wire coupled to a grounded conductor its entire length, and the pair behaves like neither piece alone. The pole was always going to be part of the antenna. Better to let it be the antenna.

Your SWR Meter Is Answering the Wrong Question

“But it tunes 1:1.” It does, and that is the cruelest part. Walter Maxwell, W2DU, spent a book -- Reflections -- on this exact point: SWR describes the match between your transmitter and the load. It says nothing about what the load does with the power. A resistor tunes beautifully. A lossy earth return tunes beautifully. The wattmeter is satisfied and the watts are warming the ground.

The end-fed half-wave with a 49:1 has its own version of this trap. With no deliberate return, the coax shield becomes the other half of the antenna -- common-mode current, the thing Jim Brown, K9YC, has measured and documented for years in his ferrite work. The feedline radiates on transmit and, worse, receives every noise source in the house on the way back in. If an EFHW hears the neighborhood better than it hears the band, that is usually why.

Put Both Halves in the Air

The clean answer to “where does the other half go” is: up. A vertical dipole puts both halves of the circuit in the aluminum above the lawn. The current flows out one element and back the other, the loop is complete by design, and the earth is not in the current path. No radials because none are needed -- not as a marketing line, but as a consequence of the circuit.

That is what a Greyline is: a vertical dipole that happens to look like a flagpole, because for an HOA operator, looking like a flagpole is the entire job. The HOA sees a flagpole. The ionosphere sees a complete antenna.

One Question Before You Spend a Dollar

The operator who started the thread that prompted this piece mentioned he holds a Technician license. So before anyone spends money on any antenna -- ours included -- here is the question that matters more: what does your license let you use?

On HF phone, a US Technician has 10 meters from 28.300 to 28.500, plus CW segments on 80, 40, and 15. That means a Technician judging HF is judging it on one band -- and 10 meters is the moodiest band on the dial, wide open one afternoon and dead for a week. The antenna is not the problem. The sample size is.

The General exam is thirty-five questions and a weekend of study, and it opens nearly all of HF. It is the single highest-gain upgrade in amateur radio, it costs almost nothing, and no antenna at any price substitutes for it. Get the General first. Then decide what to put in the air, with the whole spectrum in front of you.

Do not take our word for any of it. The short-vertical-versus-radials argument has been fought for thirty years by people who measure things, and the whole record is open: the TopBand archive, and the Greyline bookshelf -- Zavrel, Kraus, Severns, Maxwell, Brown -- with titles so you can pull the originals.

Built and written in Sun Valley, Idaho, where the flagpoles come out of the shop one at a time. Ham Radio is fun again! Pass it on...

73,
Jon Kimball, KL2A
Greyline Performance
greylineperformance.com