Contest OMs Ditched Their Verticals After This “No-Radials” Inverted-L
Three contest operators told us the same story: they tried an EFHW Inverted-L for a contest weekend… and their “trusted” vertical never went back up.
If you’ve ever built a serious low-band vertical setup, you know the pain: radials everywhere, endless ground experiments, SWR that shifts when it rains, and a garden that looks like a copper spiderweb. The EFHW Inverted-L flips that script: one radiator wire, a purpose-built transformer, a short counterpoise, and you’re on the air.
- Strong results on 160/80/40 without building a radial farm
- A repeatable, controllable return path (instead of “whatever your coax touches today”)
- Fast deployment for contest weekends, portable setups, and small gardens
The dirty secret of 160/80/40: most “vertical problems” are really ground problems
On the top bands, the enemy is rarely “not enough wire.” It’s the earth under it. A ground-mounted 1/4-wave vertical (or a classic 1/4-wave inverted-L fed at the base) has maximum RF current right at ground level. That means a lot of the system’s current must return through the ground interface (radials + soil).
If that return path is lossy, you are literally heating the ground instead of radiating. Broadcast engineers solved this decades ago with massive ground systems. Most amateur installs simply can’t (or won’t) do that at home.
Loss in a resistive return path scales with I²R. A base-fed quarter-wave is a high-current feedpoint, right where the return path is worst. That’s why “a decent vertical” is often 90% ground system and 10% radiator.
Meet the antenna that “cheats” the ground: the EFHW Inverted-L
EFHW means End-Fed Half-Wave. A resonant half-wave has a key property: at the end of the wire, the impedance is high (high voltage, low current). The EFHW Inverted-L keeps that end-feed behavior, but uses an L shape (vertical up, then horizontal out) so it’s practical on the top bands.
This matters because the feedpoint is a lower current point than a quarter-wave base feed. Any unavoidable “ground-ish” return resistance tends to hurt a lot less than it does at the base of a vertical. That’s why many operators see an EFHW Inverted-L outperform a “real” vertical that doesn’t have a broadcast-grade radial field.
“No radials” doesn’t mean “no return path” (it means no radial farm)
Every antenna needs a return path. “No radials” does not mean “no return current.” It means you don’t need the big vertical-style radial field to make it work well.
An EFHW Inverted-L completes its circuit using a combination of:
- Capacitance to the environment (displacement current)
- A short, intentional counterpoise at the transformer reference/ground point
- And (if you don’t control it) the outside of the coax shield
That last bullet is why experienced builders focus less on “radials vs no radials” and more on common-mode control. You want the return path to be intentional and repeatable, not “random coax behavior.”
• Start with a short counterpoise around 0.02–0.05 λ on the lowest band.
• Place a 1:1 current choke roughly 0.05–0.1 λ down the coax from the transformer (and add a second choke at the shack entry if needed).
(Exact lengths vary with routing, height, and the local environment. The goal is to control where the return current flows.)
What’s special about the RF.Guru EFHW Inverted-L approach
We don’t build one transformer and pretend it covers “everything.” The RF.Guru approach is band-optimized models with a multi-core stack for thermal headroom and predictable behavior, designed around how these antennas behave in real installs (height, nearby objects, and a controlled return path).
Why 68:1 on 160m, and 70:1 on 80m and 40m
These ratios fall out of two practical realities: (1) the real-world end impedance of an inverted-L EFHW at typical heights, and (2) the transformer’s need for high magnetizing reactance where it matters most (low frequency).
If the end impedance is on the order of a few kΩ, then a ratio in the 68:1–70:1 neighborhood tends to land you near 50 Ω, while keeping the transformer operating in a lower-loss region when designed correctly.
(EFHW impedance is not a fixed “book number.” It moves with height, coupling, and the return-path control.)
The 49:1 trap on the low bands
A 49:1 isn’t “bad.” It’s just commonly misapplied, especially when people try to make a single transformer “cover 80–10m” while still expecting cool cores and high efficiency on 160/80.
On the low bands, too little primary inductance can drive heavy magnetizing current (extra heat and loss). Some builds “fix” the VNA plot with a shunt capacitor, but a prettier SWR curve does not automatically mean lower loss at power.
Why we use mix 77 on 160/80 (and not “whatever ferrite was on the bench”)
For 160/80, the transformer must provide high magnetizing inductance without becoming a space heater. That’s where high-µ MnZn materials like mix 77 (when used correctly and with adequate core cross-section) can shine in band-optimized designs.
For higher bands, material choice and winding strategy often change to keep losses low and self-resonance behavior well controlled.
Why a short counterpoise connected to an RVS/INOX peg works
A short counterpoise works because you’re not trying to build a full ground plane. You’re creating a stable reference for return currents while keeping the system predictable and keeping the coax from “deciding” to become your counterpoise.
Practical starting lengths (ballpark):
- 160m: ~1.6–5 m
- 80m: ~0.8–2.5 m
- 40m: ~0.4–1.2 m
Tip: once you have a stable baseline, small changes in counterpoise length and choke placement can be used as “fine control” to reduce common-mode and improve repeatability.
Why the radial field on a normal Inverted-L or 1/4 vertical is often more lossy
A classic 1/4-wave vertical (or base-fed 1/4-wave inverted-L) is a current-fed antenna at the bottom. Current is highest where the return path is usually worst: at ground level. Even with “a lot of radials,” you don’t magically remove soil loss, you just reduce it.
The convenience win (and why contest stations care)
Contests are about results per hour of effort. The EFHW Inverted-L is simply easier to deploy:
- Feedpoint can be kept low and accessible (good for weatherproofing and service)
- No lawn-full of radials
- Works in small gardens, off trees, or rooftop supports
- Hybrid behavior: low-angle DX support from the vertical section plus higher-angle coverage from the horizontal section
Quick honesty check: transformer loss is real (and we design around it)
EFHWs do have transformer losses. That’s why ratio, ferrite material, core cross-section, winding strategy, and choke control matter. The goal is simple: keep transformer loss low enough that the antenna can “cheat the ground” and still win in real installs.
End-fed half-waves can present high RF voltage at/near the feedpoint hardware. Keep the feedpoint area away from people and pets, and use proper strain relief and weatherproofing.
The “do it right” checklist
- Use a short, intentional counterpoise at the transformer reference point
- Control common-mode: place a 1:1 choke down the coax, and add one at shack entry if needed
- Route coax deliberately so it doesn’t become the main radiator/counterpoise
- Keep the feedpoint area mechanically solid and electrically safe
Bottom line
If your vertical is truly outstanding, you probably did the hard part: the ground system. But if you’re like most of us (limited space, limited time, mediocre soil), the EFHW Inverted-L is a brutally effective upgrade on 160/80/40: less ground-loss drama, no radial farm, DX + local coverage in one, and an install you can actually repeat.
And yes… it’s also the antenna that keeps producing the same sentence from contest operators: “I tried it once, and the vertical never went back up.”
Mini-FAQ
- Is it really “no radials”? ... It’s “no radial farm.” You still need a return path, but it’s controlled with a short counterpoise and choking.
- Where do I place the choke? ... Start around 0.05–0.1λ down the feedline from the transformer, then add a second choke at the shack entry if needed.
- Does the direction of the horizontal leg matter? ... Sometimes on higher bands and higher horizontal heights. On the top bands, install height and common-mode control usually matter more than “pointing.”
- Can I add a big radial field anyway? ... You can, but it can change the system behavior (and the best matching approach may change too). Start simple and measure.
- Why not just use 49:1 for everything? ... On low bands, transformer inductance and losses become critical. Band-optimized designs often stay cooler and behave more predictably.
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