Why use tinned copper braid to bond the balun to the aluminium pole?

This seemingly simple choice is the result of practical RF engineering and experience.

Let’s break down the logic behind it:

Flexibility That Bonds

Tinned copper braid isn’t just pliable—it’s perfectly suited for conforming to irregular surfaces. Whether you're wrapping it around a cylindrical pole or shaping it to match the contours of a balun housing, the braid adapts. This ensures maximum surface contact and, consequently, a low-impedance connection that's critical at RF.

Corrosion Resistance Built In

Outdoor connections are harsh environments: moisture, UV, and dissimilar metals. Pure copper against aluminium? A corrosion time bomb. But tinning the braid acts as a sacrificial barrier that slows galvanic corrosion dramatically, ensuring longevity and consistent performance.

Wide Surface, Low Impedance

At HF and above, it's all about the skin effect. RF currents flow along surfaces—not through the core of the conductor. A broad, flat braid offers more surface area than a round wire, which directly translates to lower RF impedance. This helps suppress common-mode currents and maintain clean signals.

Stainless Steel Meets Soft Copper—Perfectly

The RVS (stainless steel) jubilee clip provides firm, vibration-resistant clamping pressure. Combine that with a soft, forgiving braid, and you get a mechanically reliable and electrically solid bond. Unlike rigid connections that can loosen or fatigue, this combo remains resilient over time.

Reduced Galvanic Risk

Direct copper-to-aluminium contact is a recipe for accelerated corrosion. But the tin layer serves as a buffer, slowing this reaction and making the bond more chemically stable in the long term—especially important for antennas left in the field year-round.

Easy to Inspect, Easy to Replace

Need to check the connection? No problem. The exposed braid and clip make for a visual inspection and tool-free replacement if needed—far easier than soldered or crimped alternatives hidden inside enclosures.

This isn’t just a random choice of materials. The tinned copper braid with an RVS jubilee clip is a tried-and-tested solution that hits all the right notes: low RF impedance, mechanical reliability, corrosion resistance, and ease of maintenance. It’s what we use—because it works.

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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.