Common Coaxial Cable Mistakes in Amateur Radio

Many amateur radio performance problems can be traced to coaxial cable mistakes rather than equipment failure. Improper cable selection, poor installation practices, and overlooked maintenance issues often lead to excessive signal loss, noise, and unreliable operation.

This guide highlights common coaxial cable mistakes and explains how avoiding them can improve station efficiency and long-term reliability.

Using the Wrong Coax for the Frequency

One of the most common mistakes is selecting coaxial cable that performs poorly at the intended operating frequency. High-loss coax that works acceptably on HF can introduce severe attenuation on VHF or UHF.

• Using small-diameter coax for long VHF/UHF runs
• Ignoring published attenuation specifications

Excessive Cable Length

Longer feedlines increase signal loss and reduce overall system efficiency. Unnecessary cable length adds attenuation and should be avoided whenever possible.

• Coiling excess coax instead of cutting to length
• Routing feedline inefficiently

Poor Connector Installation

Improperly installed connectors cause impedance mismatches, signal loss, and intermittent operation. Connector quality and correct installation techniques are critical to reliable performance.

• Incorrect crimping or soldering
• Loose or poorly fitted connectors

Inadequate Weatherproofing

Moisture intrusion is a leading cause of coaxial cable failure. Water entering the cable or connectors leads to corrosion, increased loss, and eventual feedline replacement.

• Unsealed outdoor connectors
• Failure to inspect weatherproofing over time

Sharp Bends & Mechanical Stress

Excessive bending or physical stress can damage the coaxial cable’s dielectric and shield, degrading performance.

• Bending coax tighter than the recommended minimum radius
• Lack of strain relief at connectors and entry points

Ignoring Feedline Maintenance

Coaxial cable is often installed and forgotten. Regular inspection helps identify problems before they cause significant performance degradation.

• Checking connectors for corrosion or looseness
• Inspecting jacket condition and support points

Related Coax & Feedline Guides

→ How to Choose the Right Coaxial Cable
→ Coaxial Cable Types & Characteristics
→ Feedline Loss, Attenuation & Frequency Effects
→ Installing & Weatherproofing Coaxial Cable

This page is part of the Elmer Reference Library and is intended to help amateur radio operators avoid common coaxial cable mistakes that reduce performance and reliability.