Why the EFHW Inverted-L Works Without Radials

(And what “without radials” really means in the real world.)

An EFHW (End-Fed Half-Wave) in an inverted-L shape is one of those antennas that seems to “break the rules”: it’s fed at one end, it often tunes on several HF bands, and many people install it with no classic radial field at all... yet it still makes contacts.

The key is simple: an EFHW inverted-L is not a quarter-wave vertical that depends on a low-loss ground system. It’s a resonant half-wave radiator fed at a point where current is naturally low. That changes everything about how (and how much) a “return path” has to be provided.

First: “Radials” are a solution to a specific problem

When hams say radials, they usually mean the ground system under a vertical monopole: lots of wires on or under the soil.

Those radials exist because a ¼-wave vertical has maximum RF current at the base (right where you feed it). The “other half” of the antenna is effectively the ground plane / earth return. Bare soil is lossy at RF, so without radials, a meaningful chunk of power gets burned up as heat instead of being radiated.

So for a ¼-wave vertical, radials are mainly about efficiency: reducing ground loss by providing a low-resistance RF return.

An EFHW is a different animal: half-wave resonance + high feedpoint impedance

A true EFHW on its lowest band is a half-wavelength radiator. On a half-wave wire:

• At the ends: voltage is high, current is low.
• Near the center: current is high, voltage is low.
• End-feed impedance: typically in the kΩ range (often a few thousand ohms).

That’s why EFHW systems almost always use a 49:1-ish impedance transformer (and sometimes other ratios depending on the design target and environment): you’re transforming something like ~2–3 kΩ down toward 50 Ω for coax.

Feedpoint current intuition (quick numbers)

Just to build intuition, compare the feedpoint current at 100 W:

Lower feedpoint current is a big reason why an EFHW inverted-L can remain usable without a large, deliberate radial field.

“No radials” does NOT mean “no return path”

This part is crucial: every antenna system is an AC circuit. If current goes out, it must come back somehow. End-fed antennas do not magically avoid that.

So where does the return current go when there’s no radial field? Usually into one (or more) of these:

• Displacement current (capacitance to earth / nearby objects)
  At RF, a return path can exist through electric fields (capacitance). In end-fed systems, this displacement current closes the circuit without needing a big mat of wires on the soil.
• The outside of the coax shield
  In many practical EFHW installations, the coax outer surface becomes part of the counterpoise/return conductor... meaning the feedline becomes part of the antenna system unless you control it.
• A short counterpoise wire or station bonding reference
  Many EFHW matching units include a counterpoise/ground lug for exactly this reason: a small intentional reference can stabilize behavior.

Why the inverted-L shape makes “no radials” easier

An inverted-L is typically fed near ground at the base of the vertical leg, then runs up and over. That geometry tends to make non-radial return paths easier to realize:

• More capacitance to the surroundings
  The vertical section and nearby ground/objects create strong electric fields, and the horizontal run increases capacitive coupling. More coupling makes displacement currents “easier.”
• End feed stays a low-current point
  Even though the radiator is bent, it can still behave as a half-wave resonator on its design band, keeping the end feed in a high-voltage / low-current region (relative to low-Z feeds).

The tradeoff: it works, but can get unpredictable unless you control the return

If the coax shield is acting as the counterpoise, then:

• Coax length and routing can change SWR.
• The pattern can shift (because now part of the antenna is the feedline).
• You can get RF in the shack and higher received noise.

This is why experienced builders focus less on “radials vs no radials” and more on controlling common-mode current.

Practical ways to make an EFHW inverted-L behave better

Give it an intentional counterpoise (even a short one)

You don’t need a field of 30 radials like a ¼-wave vertical might. A short counterpoise often stabilizes SWR and repeatability.

• Counterpoise length: start around 0.02–0.05 λ of the lowest band, connected at the transformer ground/reference point.
• Avoid “accidentally huge” counterpoises: making the counterpoise very long can re-introduce installation-dependent behavior and common-mode surprises.

Use a proper 1:1 current choke to keep RF where you want it

A choke doesn’t “make the antenna work” by itself... but it can stop the coax from becoming the radiating return conductor in places you don’t want (like inside your shack).

• Choke placement: start around 0.05–0.1 λ down the coax from the transformer.
• Second choke: add one at the shack entry if you still see RF-in-the-shack or noise coupling.

Accept the default reality: “no radials” often means “the coax is the radial”

If you do nothing else, this is the common outcome. It’s not automatically “bad”... but it does mean performance and SWR can be installation-dependent.

Common confusion: two antennas get called “inverted-L”

This is where many online arguments come from. These are not the same antenna:

• ¼-wave (or electrically short) inverted-L vertical
  A monopole with top loading. Radials are strongly recommended for efficiency.
• EFHW inverted-L (half-wave resonant, end-fed)
  A half-wave resonator fed at the end through a transformer. It can work without a large radial field because feedpoint current is relatively low and the return can be capacitive / via a small counterpoise / via coax (if uncontrolled).

Safety note: EFHW end feeding creates high voltage

Because the end impedance is high, voltages at/near the transformer and at the end region can be surprisingly large even at modest power.

Keep the transformer/feed area away from people/pets, use proper insulation and strain relief, and follow RF exposure guidance.

Bottom line

An EFHW inverted-L can “work without radials” because:

• It’s a half-wave resonant radiator with high feedpoint impedance and relatively low feedpoint current, so it’s less dependent on a low-loss ground system than a ¼-wave vertical.
• The circuit is completed by displacement current (capacitance to earth/objects) and/or an incidental counterpoise (often the coax shield).
• The inverted-L geometry typically increases coupling to the environment, making that non-radial return path easier to realize in practice.

But it never truly operates with “no return path”... it simply operates without a large, deliberate radial field, and that can come with common-mode and repeatability tradeoffs unless you control it.

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