Why RG58 Coax Is the Worst Cable You Could Use in 2025

RG58 was once the go-to coax for ham radio setups, CB rigs, and even lab benches. But in 2025’s world full of RFI, Wi-Fi, LTE, EV chargers, and solar inverters, this old standard is showing its age. If you’re still relying on RG58, you’re leaving performance on the table—and possibly creating your own noise nightmare.

The Big Problem With RG58

• Shielding: At best, 40–50 dB isolation. Modern RFI sources easily couple through, making your receiver noisier than it should be.
• Loss: At HF you can get away with it, but by VHF/UHF the losses are brutal—especially with long runs.
• Durability: The braid and dielectric degrade faster outdoors. UV and moisture wreak havoc on classic RG58.
• Mismatch with today’s rigs: High-power HF radios and SDR transceivers expect cables with lower loss and better shielding to avoid front-end overload.

Better Alternatives

In most cases, Messi & Paoloni cables like Ultraflex 7, Ultraflex 10, or Hyperflex 10 are smarter choices. These offer:

• 90–100 dB shielding effectiveness — keeping RFI out.
• Lower attenuation — especially critical for VHF, UHF, and microwaves.
• Longer lifespan outdoors thanks to UV-resistant jackets.

(Note: Yes, you can still use RG58 for short jumpers inside the shack or even to wind small low-power chokes. But don’t expect it to perform miracles in noisy RF environments.)

When RG58 Still Makes Sense

• Short test cables on the bench (under 1–2 m).
• QRP or portable ops where weight matters more than performance.
• Legacy gear or patch cables with BNC connectors.
• DIY low-power choke experiments with ferrite cores.

Questions or experiences to share? Contact RF.Guru.

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