There's no such things as 72 or 75 ohm ladder line.

Ladder-line wires are spaced much too far apart and have mostly air
insulation. They have impedances from 300 ohms and upwards.

Expect to find very low impedances only with twin-wires embedded in a thick,
circular or elliptical PVC sheath. Loss per unit length is quite high and
suitable only for directly feeding, resonant, single-band, 1/2-wave dipoles
at the lower frequencies.

Zip-cord and twin speaker cables have Zo between 120 and 135 ohms. 16 to
20-gauge, colourless, speaker cables make a fair compromise between
impedance, loss, SWR and small size. And exact impedance values are never
critical at HF.
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Reg, G4FGQ