Ham Radio Articles

Educational guides, tutorials, and technical deep-dives about antennas and amateur radio

Ham operator measuring a quarter-wave coaxial transformer with a network analyzer on a workbench

November 17, 2025

Designing a Quarter‑Wave Coaxial Matching Transformer

Learn how to use a λ/4 coax section to match non‑50 Ω antennas to 50 Ω feed lines. Includes formulas, step‑by‑step examples, and practical build tips.

End-fed half-wave wire antenna sloping from a mast with a small transformer box and coax feedline in a backyard ham radio setup

Nov 14, 2025

Designing and Building a 49:1 End‑Fed Half‑Wave Antenna for HF

A step‑by‑step guide to calculate wire length, wind the 49:1 transformer, and tune a multiband EFHW for reliable HF performance with low loss.

A quarter-wave ground-plane vertical antenna with four sloped radials being tuned on a rooftop using an antenna analyzer.

Nov 10, 2025

Designing a Quarter‑Wave Ground‑Plane Vertical: Dimensions, Matching, and Installation

A practical guide to building and tuning a quarter-wave ground-plane vertical antenna—dimensions, impedance control, radials, matching, and installation tips.

Ham operator installing low-loss coaxial cable from rooftop antenna to grounded shack entry panel with test equipment on the bench

Nov 7, 2025

Choosing the Right Coax: Calculating Feedline Loss, Power Handling, and Length

Learn how to choose coaxial cable by calculating line loss, power handling, and electrical length—plus real examples and practical station tips.

Technical diagram showing SWR and impedance matching concepts including dipole antenna with standing waves, L-C matching network, reflection coefficient formula, and SWR meter

Nov 2, 2025

Understanding SWR and Impedance Matching in Ham Radio Antennas