When Big-Box Antenna Content Sounds Like AI

A Radials Guide That Rebuilds Old Myths

Every few weeks I try to write something that helps radio amateurs move one step away from the old myths. Not because myths are funny, although sometimes they are, but because bad RF explanations lead to bad installations, hot microphones, unstable SWR, noisy receivers, burned ferrites, and disappointed operators.

That is why it is frustrating when a large, respected retailer publishes a polished antenna article that appears, at first glance, to explain radials and counterpoises clearly, but then reinforces several of the very myths many of us are trying to remove from amateur radio.

The article in question is WiMo’s public guide about radials and counterweights:

https://www.wimo.com/en/radials

This is not a personal attack on the authors, nor on WiMo as a company. Retailers have an important role in educating newcomers, and the article contains useful practical advice. But when an educational text mixes correct principles with overconfident shortcuts, the result can be more damaging than silence. It gives the reader the feeling of understanding while quietly planting new misconceptions.

The Good Part: Radials Are Not Optional Decoration

The WiMo article starts from a correct and important idea: a vertical or other unbalanced antenna system needs a return path. The visible radiator is only half the story. The other half is the radial field, counterpoise, vehicle body, metal roof, feedline shield, mast, building structure, or some other path that allows RF current to complete the circuit.

That message is valuable. Many hams still believe that a vertical antenna is just “the whip,” or that a ground rod is automatically an RF ground. In reality, a ground rod may be important for safety, static discharge, and lightning bonding, but it is usually a poor RF return system on HF. A radial field or counterpoise system is not an accessory. It is part of the antenna.

The article also correctly points out that elevated radials and ground-level radials behave differently. Elevated radials can be resonant and efficient with relatively few wires. Ground-mounted radial systems are usually more broadband, but often need more conductor material to reduce ground loss.

So the foundation is not bad. The problem is what gets built on top of it.

Myth Rebuilt: “An End-Fed Half-Wave Needs No Radials”

One of the most misleading statements in the article is the claim that an end-fed half-wave antenna does not require radials because of its high base impedance.

That sentence is technically incomplete. A resonant end-fed half-wave does not normally need a full quarter-wave radial field like a classic quarter-wave vertical. But it still needs a return path. That path may be small, distributed, capacitive, or hidden, but it does not disappear.

In many real EFHW installations, the return path is one of the following:

• the outside of the coax shield;
• a short intentional counterpoise wire;
• a mast or support structure;
• station wiring and equipment chassis;
• stray capacitance through the transformer, enclosure, operator, and environment.

The high feedpoint impedance reduces the return current. It does not abolish Maxwell’s equations.

This is exactly where many EFHW myths begin. Someone says “no radials needed,” the coax quietly becomes the missing counterpoise, and later the operator wonders why SWR changes with coax length, why the shack has RF problems, or why adding a choke suddenly shifts the tuning.

The better statement would be:

Myth Rebuilt: “Ground Radials Lose Their Resonance, So Length Does Not Matter”

The article says that radials laid on the ground or slightly buried become so damped by the soil that they completely lose their resonance. It then concludes that exact radial length becomes irrelevant.

That is too broad.

Dense ground-mounted radial systems are indeed relatively broadband. Once you have many wires, small differences in individual radial length usually matter much less than the total amount of conductor, the coverage near the feedpoint, and the general size of the radial field.

But a sparse radial system is different. Four or eight radials on the ground can still show strong length sensitivity. Soil damps resonance, but it does not magically erase all electrical length effects in every installation.

This distinction matters because many amateurs do not install 60 radials. They install four, eight, maybe twelve wires and then assume the “length does not matter” rule applies. That can lead to poor efficiency, unexpected impedance, feedline current, and bad repeatability.

The better practical rule is:

Myth Rebuilt: “Many Short Wires Are Always Better Than a Few Long Ones”

The phrase “many short wires are better than a few long wires” is a useful rule of thumb only when the available wire budget and installation conditions are understood.

The main current density in a vertical ground system is indeed highest near the base of the antenna. That means wire coverage close to the feedpoint is very important. A few very long radials with poor coverage near the base are not an ideal use of material.

But that does not mean radial length is irrelevant. A radial field also needs physical extent. If all wires are extremely short compared with the wavelength, the system may still suffer high ground loss. The right answer depends on band, soil, antenna height, available area, and the total amount of conductor.

For small gardens, the realistic advice is not “length does not matter.” The realistic advice is: use as many wires as practical, cover the area near the feedpoint well, extend the field as far as the property allows, and do not confuse a neat SWR with high radiation efficiency.

Myth Rebuilt: “Elevated Radials Need One to Two Meters of Height”

The article suggests that elevated radials must be one to two meters above ground to escape ground damping.

That is not a universal RF rule. It is a distance in meters, not an electrical distance in wavelengths.

One meter means something completely different on 160 meters, 40 meters, 10 meters, 2 meters, and 70 centimeters. On the low HF bands, one meter is electrically very close to the ground. On VHF, it can be a large fraction of a wavelength.

Elevated radials should be evaluated as part of the complete antenna system. Their height, length, number, angle, ground interaction, feedline routing, and nearby structures all interact. A fixed height rule may be useful as casual installation advice, but it should not be presented as a physical threshold.

The 45-Degree Radial Angle Is Not a Magic DX Lever

The article correctly notes that drooping the radials of a ground-plane antenna can raise the feedpoint impedance closer to 50 ohms. That is a familiar and useful design technique.

The overreach comes when this is presented as a precise and trouble-free match to standard coax, and as a way to generate exactly the desired flat radiation pattern for DX.

Drooping radials changes feedpoint impedance. It can move a roughly 35-ohm quarter-wave ground-plane system toward 50 ohms. But the final impedance depends on radial length, radial count, height, conductor diameter, support mast, feedline routing, soil, and nearby metalwork.

The elevation pattern is also not controlled by radial angle alone. Pattern depends on the full current distribution and the environment. On HF, ground conductivity and takeoff angle are deeply linked. A radial angle cannot magically force the energy to “go to the horizon.”

So yes, sloping radials can be useful. No, they are not a universal DX-pattern control knob.

Coax as Counterpoise: The Velocity-Factor Trap

One of the clearest technical mistakes in the article is the suggestion that a common-mode choke should be placed at exactly one quarter wavelength multiplied by the coaxial cable’s velocity factor.

That sounds tidy. It is also wrong in many real installations.

The published velocity factor of coaxial cable describes the wave travelling inside the cable, between the center conductor and the inside of the shield. But when the outside of the coax shield is used as a counterpoise, the current is not travelling inside the coaxial transmission line. It is travelling on the outside of the shield as a common-mode conductor in the surrounding environment.

That outside-shield velocity depends on the jacket, ground proximity, routing, mast, nearby conductors, moisture, and the environment around the cable. It is not automatically the manufacturer’s internal coax velocity factor.

This error matters because many portable antennas rely, intentionally or accidentally, on the feedline shield as part of the antenna. If you choke the coax at the wrong place, you may not define the counterpoise at all. You may only move the problem.

Handheld Radios Are Not Usually Half-Wave or 5/8-Wave Dipoles

The article claims that handheld radios solve the lack of a ground path by using half-wave or 5/8-wave dipoles. This is not how most handheld radio antennas work.

The classic rubber-duck antenna is usually an electrically short loaded monopole or helical monopole. The return path is not absent. It is distributed through the radio body, PCB, battery, operator’s hand, body capacitance, belt clip, accessories, speaker microphone cable, and nearby environment.

That is why handheld performance changes when you hold the radio differently, connect a speaker microphone, add a counterpoise wire, place the radio near your body, or connect it to an external antenna.

A 5/8-wave vertical is also not a magic “no counterpoise needed” antenna. It normally still needs a return system and matching network. Calling handheld antennas half-wave or 5/8-wave dipoles creates a new myth while trying to explain an old one.

Magnetic Mounts: Capacitive Coupling Is Real, But Not Automatically Perfect

The article correctly states that magnetic mounts couple to the vehicle body capacitively through the paint and protective layer. That part is true and important. A magnetic mount does not require DC metal-to-metal contact to create an RF path.

But the article then implies that this coupling is highly efficient as a general rule.

Capacitive coupling has reactance. That reactance depends on frequency, base area, paint thickness, pad material, moisture, mounting location, and vehicle body geometry. At VHF and UHF, many magnetic mounts work very well. On lower HF bands, the same idea can become much more compromised.

The right lesson is not “mag mounts are automatically highly efficient.” The right lesson is that they are capacitively coupled, and that coupling must be adequate for the frequency and antenna current involved.

SWR Is Not Efficiency

The article repeatedly ties good SWR too closely to efficient radiation. This is one of the most persistent myths in amateur radio.

A low SWR tells you that the impedance match looks acceptable at the measurement point. It does not prove that the antenna is efficient. It does not prove that the pattern is useful. It does not prove that the coax shield is clean. It does not prove that ground loss is low.

A lossy antenna system can have a beautiful SWR because loss resistance has been added to the system. A tuner can create a perfect 1:1 match into a very inefficient antenna. A poor radial field can sometimes make impedance look more convenient while wasting power as heat in the soil.

Efficiency must be evaluated from losses, current distribution, field strength, thermal behavior, pattern, and real-world repeatability. SWR is only one measurement, and it is often the least informative one when the antenna system is not well defined.

Elevated Radial Safety: Correct Warning, Wrong Certainty

The article correctly warns that elevated radial ends can carry high RF voltage. That warning should absolutely remain. Resonant elevated radials are not harmless wires. The open ends can be high-voltage points, especially at higher transmitter power.

The only problem is the phrase that the radial ends carry exactly the same RF voltage as the tip of the vertical. That is too absolute. Voltage distribution depends on the complete geometry, number of radials, current division, coupling, feedpoint voltage, and surroundings.

The practical safety message is simple enough without overclaiming:

Good Education Requires Less Certainty, Not More

The problem with the WiMo article is not that every sentence is wrong. The problem is that many sentences are too certain.

Antenna systems are not made from isolated textbook fragments. The radial field, feedline, choke, tuner, mast, soil, operator, building, and nearby conductors all interact. When an article presents installation-dependent behavior as universal truth, it gives beginners simple rules that break as soon as they build a real antenna.

That is exactly how myths survive.

Someone reads that EFHW antennas need no radials. Then their coax radiates. Someone reads that ground-radial length is irrelevant. Then their four-wire radial system performs poorly. Someone reads that SWR proves efficiency. Then they install a lossy system with a beautiful meter reading. Someone reads that coax counterpoise length uses the cable velocity factor. Then their choke goes in the wrong place.

All of these mistakes are avoidable if we use more precise language.

A Cleaner Way to Explain Radials and Counterpoises

If I had to rewrite the topic from first principles, I would start with these statements:

• A vertical or unbalanced antenna needs a defined RF return path.
• A ground rod is not a radial field.
• An EFHW needs less return current than a low-impedance monopole, but it still needs a return path.
• Ground-mounted radial systems become more forgiving as they become denser.
• Sparse radial systems can still be length-sensitive.
• Elevated radials are part of the antenna and must be tuned in the installed geometry.
• Coax shield current is not automatically bad if it is intentionally used as a counterpoise, but it must be controlled.
• A common-mode choke defines an RF boundary only when the return path before it is adequate.
• SWR is not efficiency.
• Safety ground, lightning ground, and RF counterpoise are related but not the same thing.

That version is less dramatic, but it survives contact with real antennas.

The Real Lesson

Radials are not magic wires. Counterpoises are not mystical grounding accessories. Chokes are not universal erasers. And SWR is not a certificate of antenna quality.

The real antenna is the complete current path.

That includes the radiator, the return system, the feedline, the common-mode boundary, the tuner, the soil, the support structure, and the surrounding environment. Once you understand that, most radial myths start to collapse by themselves.

Large retailers can help the hobby tremendously by publishing better educational material. But polished wording is not enough. In RF, a confident sentence can still be wrong.

And when the goal is to help hams move away from myths, the last thing we need is a new generation of professionally formatted misconceptions.

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