The “Faraday Cloth” Radial Myth

The “Faraday Cloth” Radial Myth

Why conductive mesh is not a replacement for proper radials

In stealth or portable setups, some operators experiment with conductive mesh sheets (“Faraday cloth”, RF shielding fabric, wire screen) laid under a vertical. The assumption is simple:

“It’s conductive, so it must act like a ground plane or radials.”

Myth: a patch of conductive fabric or small wire mesh is equivalent to a radial field. Reality: it usually is not — and it won’t magically make a vertical efficient. Here’s why.

Conductivity Isn’t Enough — You Need the Right Current Distribution

• Radials aren’t just “some metal near the base.” They are deliberate conductors of specific length that provide a low‑impedance RF return path for displacement currents at the feedpoint.
• A flat cloth or small mesh — especially if resistive — cannot support the correct current distribution needed to act as an effective counterpoise.

Size Matters — A Lot

Controlled experiments (e.g., N6LF) show the radius of the conductive region strongly impacts ground loss. On 40 m, even a ~2 m radius mesh is only modest help; losses remain high unless the radial field or screen extends to roughly λ/8–λ/4.

Example: A 1.5 m × 1.5 m copper mesh under a 40 m vertical is “better than nothing,” but the return currents extend well beyond that footprint. The cloth becomes a lossy patch, not a low‑loss mirror.

Fabric ≠ Copper Radial

• “Conductive” fabrics often measure ~0.05–0.5 Ω/sq. At HF (skin effect), their RF resistance is effectively worse than DC suggests.
• Copper wire radials have RF resistance orders of magnitude lower, keeping I²R loss small.
• Net effect: cloth dissipates more power as heat instead of returning it to the feedpoint.

“Inductive Coupling” Isn’t the Mechanism

• Verticals are mostly E‑field dominant; the return path is via capacitive/displacement current to the surrounding ground/radials.
• Radials behave as the “other plate” of a capacitor with the soil/counterpoise; they complete the RF circuit.
• A small mesh adds little effective capacitance and doesn’t complete the circuit over the region where return currents actually flow.

Yes, Fabric Can Work — If Used as Radials

You can use conductive fabric effectively by cutting it into strips and deploying them like radials. Each strip acts as a wide, flexible conductor:

• Cut 2–8 strips to lengths around λ/4 (elevated) or as long as practicable on ground; more/longer is better.
• Keep strip resistance low (choose the lowest Ω/sq cloth you can find) and ensure solid bonding at the feedpoint.
• A single square of fabric is not equivalent to multiple λ/4 conductors; one cloth won’t do the trick.

Think “radial strips,” not “blanket.” Geometry matters as much as conductivity.

Measured Reality (N6LF et al.)

• Screen/mash helps only when large and low‑resistance.
• Short wires beat small sheets; elevated, tuned radials beat large resistive surfaces.
• Ground loss is about the impedance of the return path. Build a structure that conducts RF current efficiently.

Conclusion: Don’t Get Trapped by the Cloth

1. A small conductive patch ≠ a radial field.
2. Mesh ≠ mirror unless big and low‑Ω.
3. Verticals need a capacitive return over the region where currents flow — that’s what radials provide.

If you’re going to put in effort, build real radials. Even 2–4 elevated λ/4 radials outperform any “Faraday cloth” pad. If you must use fabric, cut it into strips and deploy them as radials.

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