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Half-wave dipole
Overall length and both arms of a centre-fed dipole.
HB3YAQ · Ajdin HadzicLearning to take awayhttps://hb3yaq.ch/en/tools/dipole
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Formula & context
L = c · k / (2f); Arm = L / 2
A symmetrical half-wave dipole has two equal arms and a central feed point. k = 0.95 is an adjustable starting assumption, not a universal material constant.
A worked example
14.2 MHz and k = 0.95 give approximately 10.029 m overall and 5.014 m per arm.
Assumptions & limits
Build slightly long and measure in the intended position. This calculation does not predict feed-point impedance or bandwidth.
Planning a half-wave dipoleUnderstand the reasoning →From reading to experimenting
Half-wave dipole
14.2 MHz and k = 0.95 give approximately 10.029 m overall and 5.014 m per arm.
Open example with starting values →Frequency: 14.2 MHz · Velocity / shortening factor: 0.95 Back to the learning article →Then change exactly one value. Compare the result and use the formula to explain why it changes. The model limits below the calculator also apply here.