What RF Ground Really Is

If you’ve spent any time in amateur radio circles, you’ve probably heard the term “RF ground” thrown around with confidence — often accompanied by copper rods, thick braided straps, or debates over radial systems. But in most cases, hams confuse electrical safety grounding with radio frequency behavior. Let's set the record straight.

Does RF Ground Exist?

The short answer: not in the way many hams think. RF ground is not a universal sink where RF magically disappears. At radio frequencies, ground is not an absolute — it’s simply a reference point, and depending on frequency, environment, and geometry, its electrical properties can vary wildly. At HF and higher, “ground” is more about impedance than it is about DC continuity.

You can't dump RF into a wire and expect it to vanish unless that path presents an appropriate RF impedance. Even a perfectly grounded copper rod won’t “absorb” RF unless the system is designed for that — and most aren't.

⚠️ RF ground is not a real or universal concept in scientific or commercial RF engineering. It’s a non-scientific term, often misused and overhyped in ham radio.

Differential Mode and the Myth of Dumping RF

In balanced systems, current flows in differential mode: equal and opposite along two conductors. A center-fed dipole is a classic example. Both legs carry current, and the fields cancel in the feedline if it's symmetrical. No “RF ground” is required.

But move the feedpoint off-center (as in an OCF dipole) or go all the way to an end-fed design, and balance is lost. The coax shield becomes part of the antenna system. Hams then try to “bleed” off the unwanted current using radials, ground rods, or copper mesh. But none of these are magical — they work only if they present high enough impedance to stop common mode currents. Most of the time, the best option is to use both a choke and a high-impedance counterpoise that terminates at a high-impedance RVS ground stake or rod.

What About the Counterpoise?

A counterpoise isn’t “RF ground.” It’s a reactive structure that provides a return path or impedance match for unbalanced systems. Think of it as a high-impedance bleeder for RF energy — it's not trying to “ground” the RF, but to balance the antenna system so current stays where it belongs.

A counterpoise only works if it's sized, placed, and designed for the frequencies involved. A 2-meter long wire doesn’t “ground” 80 meters — it might as well be a capacitor. And again, it’s not the conductivity that matters most — it’s the impedance profile at RF.

Stainless Steel: A Better RF Resistor Than Copper

Here’s a surprise for many: stainless steel (RVS) is often better than copper for RF grounding systems — not because it conducts better (it doesn’t), but because it resists better. For the purpose of choking RF current — especially common mode — a material with higher resistance can often be more effective.

Think of your “RF bleed” like a resistor. You don’t want perfect conduction; you want to stop the flow of RF where it shouldn't be. That’s why stainless steel, despite being a poor DC conductor, works very well in radials, counterpoises, or chassis bonding when the goal is RF current control.

Safety Ground vs. RF Behavior

Let’s be absolutely clear: you must ground your equipment and towers for safety — lightning, electric shock, and protection of life and property. But this has nothing to do with RF performance. The safety ground and the RF return path may connect at some point, but they serve fundamentally different purposes.

Don’t confuse the green wire safety ground with an RF drain. They might touch, but they live in different worlds.

⚠️ Regulatory Reminder: Proper grounding and bonding are a legal and safety requirement — for protecting people, animals, and property. But don’t confuse regulatory safety grounding with RF behavior. They are completely different concerns. RF current will not "follow" your legal ground system unless it happens to present the correct impedance at that frequency.

So What’s the Takeaway?

  1. RF ground is not a magic RF sink.
  2. Differential current doesn’t need a ground — just symmetry.
  3. End-fed and unbalanced antennas need RF balance, not copper rods.
  4. A counterpoise is a balancing act — not a dump line. It provides the necessary reactive counterpart to the high-voltage point of the antenna system when using a voltage transformer like a 9:1 or 4:1 UNUN. While the counterpoise itself typically does not radiate significantly, the coaxial shield or other off-center components often become the unintended radiator — albeit inefficiently.
  5. RVS is often better than copper where RF current needs to stop.
  6. Safety grounding is vital — but irrelevant to RF behavior.

If your antenna system is misbehaving, don’t reach for more copper. Start with current balance, choking, and a proper understanding of field behavior. Because in the RF world, “ground” is not a hole you throw energy into. It’s just another part of the circuit — and a very misunderstood one.

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Written by Joeri Van Dooren, ON6URE – RF, electronics and software engineer, complex platform and antenna designer. Founder of RF.Guru. An expert in active and passive antennas, high-power RF transformers, and custom RF solutions, he has also engineered telecom and broadcast hardware, including set-top boxes, transcoders, and E1/T1 switchboards. His expertise spans high-power RF, embedded systems, digital signal processing, and complex software platforms, driving innovation in both amateur and professional communications industries.