Why We Don't Use Resin Potting for Our Baluns

In the past, our predecessor used resin potting as a method to protect baluns from environmental influences. While this approach can work and does provide a good level of protection, we have opted for a more advanced and industrially proven method that aligns with best practices in high-reliability RF and electrical engineering.

Instead of resin, we apply a dielectric coating to the internal components of our baluns. This coating provides excellent protection against moisture and contaminants without the bulk and rigidity of hardened resin. Our enclosures are sealed using custom-designed gaskets for all connectors and bolts. These precision-cut gaskets ensure a consistent and reliable barrier against environmental ingress. Each bolt is secured using Loctite to prevent loosening over time due to vibration or thermal cycling. Additionally, every enclosure includes a compression vent that equalises internal and external pressure, significantly reducing the risk of condensation and improving long-term durability.

This approach offers several advantages:

• Thermal Management: Resin potting can trap heat inside the balun, potentially reducing component lifespan. Our method promotes better airflow and natural heat dissipation. In addition, for extreme high-power applications, we use vents instead of compression valves to further enhance thermal relief.
• Environmental Resilience: The combination of dielectric coating, gaskets, Loctite, and pressure equalisation ensures reliable operation in harsh environments without the rigidity and potential cracking issues of hardened resin.

We fully acknowledge that resin potting can be effective when done correctly, and for certain applications, it remains a viable option. However, after extensive testing and field experience, we are confident that our coated, pressure-balanced design provides the most robust and practical solution for modern RF installations.

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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.