If you have a 1.5 swr your antenna isn't resonant

Sorry, but thanks for playing.

Your resonant impedance may be pretty much anything, depending on the exact
antenna in question. We favour antennas that are roughly 50 ohms resistive
at resonance.

Resonance is the point(s) where the antenna has little to no reactive
impedance component.

My cobra for 11M is about 2/1 and is definitely resonant.