Coax cable loss

Coax cable loss calculator

Applies the empirical α = a√f + b·f (dB/100m) formula, with metric or imperial inputs, and reports output power and efficiency automatically.

Every dB of feedline loss comes straight out of your ERP. After calculating attenuation here, plug the net output into the ERP Calculator to see how much signal actually leaves the antenna.
High loss also means more heat in the line. If you raise transmitter power to compensate, double-check the RF Exposure distances so the station still meets safety guidelines.

Ham Calculator

Three practical tools for day-to-day RF work: attenuator pads, balun design, and LC resonance.

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