A Coax dipole for 4 m

This web article details the construction of a 4-meter band coaxial dipole antenna, designed for operation between 70.000 MHz and 70.500 MHz. The resource provides a bill of materials and step-by-step assembly instructions for a half-wave dipole constructed from RG-58 coaxial cable. The design specifies a direct 50 ohm feedpoint impedance, eliminating the need for an external matching network. Construction photographs illustrate the stripping and soldering processes for the coaxial cable elements, ensuring proper electrical connection and physical integrity. The article includes specific dimensions for the radiating elements, derived from calculations for the 70 MHz band.

The project outlines the physical dimensions required for resonance at 70 MHz, with the outer braid forming one half and the inner conductor forming the other. The feedline connection is directly to the coaxial dipole's center, maintaining a 50 ohm characteristic impedance. While the article does not present SWR plots or VNA sweeps, it focuses on the mechanical construction and dimensional accuracy for achieving a functional 4-meter dipole. The design is intended for fixed station use, with no specific mention of polarization or height above ground, but implies a standard horizontal orientation for dipole operation.

DXZone Focus: Web Article | 4m Coaxial Dipole | Construction Guide | 50 ohm Feed