Wire Span
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Dipole length and VSWR

Example 14 MHz, 73 into 50

Worked inputs. Not a band allocation or a coax row.

Worked example

Each legEach leg5.095 m5.095 m16.714 ft16.714 ftTotal span10.189 m / 33.429 ft

Total length 10.1893 m / 33.4286 ft

Each leg 5.0946 m / 16.7143 ft

L_feet = 468 / f. L_meters = 142.65 / f. Leg feet = 234 / f. Leg meters = 71.325 / f.

These lengths are a formula starting point. They are not a guaranteed cut length. End effect, insulation, and height are not in the equation.

VSWR

Conditions: load 73 ohm, reference 50 ohm. Real values only. Length is not used.

Gamma 0.187

Gamma = (Z_L - Z_0) / (Z_L + Z_0)

VSWR 1.46

VSWR = (1 + |Gamma|) / (1 - |Gamma|)

Return loss 14.5635 dB

RL = -20 * log10(|Gamma|)

Reflected power 3.4966 %

P_refl = |Gamma|^2 * 100

Notes only: about 73 ohms at 180 degrees, about 58 at 120, about 50 at 90. Not interpolated.