If it’s not then check that the spindle guide line is perfectly aligned To the tonearm pivot. It should also be perfectly aligned to that. Once you’ve got it perfectly aligned on the first null point, then move over to the second. If your cartridge is an annoying one without parallel sides, then just go by the front and make sure it’s perfectly parallel to the lines. It should be absolutely square to the grid lines. If not then raise the arm and twist the cartridge slightly as needed, and lower again. Then see if the cartridge body lines up with the grid lines.

If it doesn’t quite line up then raise your arm and move the cartridge back or forth as needed until it lands precisely on the mark. Then carefully try to place the stylus on the first null point. You need to loosen off the cartridge bolts in the headshell (loose enough so that you can just about move the cartridge about, but tight enough so it stays where it is if not being deliberately moved - you may need to loosen a little and partially re-tighten for each little tweak) It should have a guide-line that has to point at the the exact centre of the point where your tone arm pivots, then you know that the protractor is perfectly positioned. The alignment protractor will have the null points marked on it, 2 of them, each within a set of grid lines. Remove the power supply from your turntable to prevent any accidents. You can print it off (make sure it prints 1:1 scale!) and very carefully punch a hole where marked, so you can fit it over your spindle. Essentially you need to decide what sort of alignment you want to go for (if you aren’t inclined to get into all that, just go for Baerwald) and then find an alignment protractor on the link provided by Ugg10 corresponding to the effective length of your tonearm.

Sme tonearm length