a Portable Vertical Write-Up Starts as Engineering

and Drifts into Marketing-Science

A practical portable vertical plus a matching transformer plus a return conductor can absolutely work. Many people have great on-air results with compact vertical systems, especially when setup time matters.

This article critiques claims and reasoning, not anyone’s enjoyment of a portable antenna. If your setup gets you on the air, that’s already a win.

Below is a technical sanity check of common “portable EFHW vertical” storytelling, using the Feb 2025 PDF “Dominator Halfwave Antenna” (KJ6ER) as an example. The goal is simple: separate what’s practical from what’s rhetorically convenient.

The first yellow flag: “No radials” is wordplay

The document says the antenna “requires no radials” while also stating it “does require a linked counterpoise.” Electrically, a counterpoise wire connected to the system ground is a radial/return conductor. It may also radiate depending on how currents distribute (and that distribution is very sensitive to height, soil, the feedline route, and choking).

If the design needs an RF return conductor, then it’s using an RF return conductor. Rebranding it doesn’t change the physics.

Where the claims go off the rails

“Up to +3 dB (2× gain)” is asserted broadly, but not supported by the paper’s own figures

A headline promise like “up to 2× gain (+3 dB)” is a strong, general claim. But later plots presented in the same write-up show much smaller differences in specific modeled scenarios. That mismatch between “marketing headline” and “shown numbers” is a classic tell.

SWR / mismatch is presented as “antenna efficiency” (major conceptual error)

The write-up uses a table labeled “SWR Efficiency” and implies that SWR ≤ 1.5:1 means the antenna is “96% efficient.” That is not what that number means.

Translating “mismatch efficiency” into “antenna efficiency” is not a small wording issue. It’s misleading, because it replaces a narrow, real concept with a broad, feel-good conclusion.

The counterpoise is described as “negligible” … while also being used as the main tuning lever

The narrative often flips depending on what needs to be claimed:

• When selling the idea of a clean half-wave vertical pattern: the counterpoise current is described as very low and of negligible impact.
• When selling the “discovery” that makes a short whip work: the counterpoise is treated as crucial and “imperative,” shifting resonance significantly.

A ~⅓-wavelength conductor connected at the feed system is not automatically “negligible.” If it can move resonance enough to justify chopping a large portion off the radiator, it’s participating in the system physics in a meaningful way (pattern and/or loss and/or current distribution).

“Half-wave vertical” becomes dubious when the length table is ~44% λ

A resonant half-wave radiator is roughly 50% of a wavelength (shortened somewhat by end effects and environment). Values around ~44% λ are far enough away that you should stop assuming “textbook half-wave behavior” without additional proof.

In plain language: the system may resonate and work fine, but the structure is likely behaving more like an asymmetric radiator (vertical element plus a significant attached return conductor) rather than a clean, isolated EFHW vertical that magically guarantees a specific DX pattern.

NEC plots referenced to 2450 Ω look “scientifically decisive,” but are easy to misread

Modeling SWR and return loss referenced to ~2450 Ω can be technically appropriate if you’re designing the antenna feedpoint to suit a 49:1 transformer. The problem is presentation: deep return loss numbers can look “perfect” to casual readers while quietly avoiding the 50 Ω reality the radio/analyzer sees.

Also: any “perfect match” chart implicitly assumes an ideal transformer unless loss is explicitly modeled. Real transformers and chokes are not lossless.

“A 56:1 is looking further down the radiator” reveals a misunderstanding

Changing transformer ratio does not “move the feedpoint down the radiator.” The feedpoint is still the feedpoint; its impedance is set by geometry, environment, and the return path. The transformer ratio only maps whatever impedance exists at that point to something closer to 50 Ω.

Comparisons are not controlled enough to justify sweeping “reach” conclusions

Charts can look quantitative while still being non-rigorous if the comparison conditions aren’t pinned down (ground assumptions, loss models, identical environments, identical feedline routing, consistent choking, etc.). Small modeled differences shouldn’t be used to justify big marketing statements unless the experimental controls are tight.

The rhetoric pattern is consistent: bold claim first, qualifying details later

This is the repeating structure:

• Lead with a bold generalized claim (“no radials,” “+3 dB,” “96% efficient,” “clean half-wave vertical”).
• Later provide figures that either don’t match the magnitude, or rely on assumptions that aren’t highlighted.
• Use technically true concepts (like mismatch loss) as stand-ins for larger conclusions (like real system efficiency).

So how do you evaluate the antenna without buying the story?

If you care about performance rather than persuasion, do checks that are hard to “wordsmith”:

Measure common-mode current on the coax

If coax current is non-trivial, then the “coax is not part of the antenna” claim is false in your setup. This is measurable with an RF clamp ammeter, or with a simple ferrite + detector method. Good choking is not a slogan; it’s a result.

Do a real A/B against a reference you trust

Compare against something boring and known (e.g., a quarter-wave vertical with four elevated radials, or a resonant dipole at a similar height). Same site, same time window, same power, and enough samples to average fading. If someone claims “gain,” ask for statistical results, not screenshots.

Treat SWR as a matching metric, not a performance metric

SWR tells you about mismatch, not radiation. You can have a gorgeous SWR curve and still waste power in transformer loss, return losses, and feedline radiation. Conversely, you can have an SWR that looks mediocre and still radiate well if the system losses are low and current is where you want it.

Bottom line

A portable vertical with a transformer and a counterpoise can be a very usable antenna system. What you should be skeptical of is the moment a document:

• equates SWR/mismatch with “antenna efficiency,”
• overclaims big, general gain advantages,
• calls a required return conductor “negligible” while also using it as the key physics knob,
• and uses modeling charts in ways that are technically true but easy to misread.

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