This calculator will calculate the radiation resistance of a Marconi antenna which is short compared to the wavelength. Formulas are taken from this excellent page by ON7YD.
Enter antenna height in metres:
Enter antenna horizontal segment length in metres:
Enter frequency in MHz:
Enter antenna impedance (dominated by ground loss plus inductor loss) in ohms:
Enter transmitter power output in watts:
The wavelength in metres is:
The radiation resistance in ohms is:
The antenna efficiency is:
The approximate antenna capacitance in pF is:
The required inductance in uH is:
The antenna current in A is:
The antenna voltage in V is:
The total radiated power in watts is:
The EIRP in watts is:
Many thanks to Ben N1VF for pointing out a mistake in the calculation of hte radiation resistance! Rectifying this mistake results in slight increase of the calculated Ra with respect to the previous version.
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