Example 28 MHz, 100 into 50
Frequency is an entered value. No allocation table.
Worked example
Total length 16.7143 ft
Each leg 8.3571 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 100 ohm, reference 50 ohm. Real values only. Length is not used.
Gamma 0.3333
Gamma = (Z_L - Z_0) / (Z_L + Z_0)
VSWR 2
VSWR = (1 + |Gamma|) / (1 - |Gamma|)
Return loss 9.5424 dB
RL = -20 * log10(|Gamma|)
Reflected power 11.1111 %
P_refl = |Gamma|^2 * 100
Notes only: about 73 ohms at 180 degrees, about 58 at 120, about 50 at 90. Not interpolated.