Vertical Antenna Length Calculator

📡 How to Build a Simple Vertical Antenna

Materials:

• Aluminum or copper wire/tubing (length based on calculator)
• Insulated base or mount
• Radials (for ¼-wave, typically 3–4 wires at least as long as the vertical)
• Coax feedline (50Ω, like RG-8X or LMR-400)
• Optional: choke balun or current balun near feedpoint

Instructions:

1. Use the calculator to find the antenna length.
2. Cut the radiating element (¼, ½, or ⅝ wave) to the calculated length.
3. Mount vertically with a non-conductive base support.
4. For ¼-wave antennas, attach 3–4 radials horizontally or slightly downward.
5. Solder or clamp the coax center to the vertical element, and shield to radials or ground.
6. Mount as high and clear of obstructions as practical.

Test the antenna with an SWR meter or antenna analyzer and trim if needed. Use weatherproofing if installed outdoors.