Calculating Matching Methods

Date: 2026-01-12

• Measure or model feed impedance at the operating frequency.
• For end-fed random wire, start with 9:1 unun (3000 to 50 ohms).
• For EFHW, use 49:1 or 64:1 transformer depending on impedance.
• For balanced feed, use a 1:1 current balun and open-wire line.
• Tune residual reactance with an antenna tuner or L-network.
• Check transformer voltage/current ratings to prevent overheating.