I agree with Simao, but with the caveat that I own the older version of the Feickert Protractor. Mine has a base the size of an LP, whereas the newer version uses a base that is about half an LP, in size. Those who own it will know what I mean. The first step is to establish stylus overhang by first placing the poointer over the tonearm pivot and while in that position, you cite the stylus on a dot (on mine) that establishes overhang. On mine, these markers are inscribed in separate arcs running from the label area out to the perimeter, depending upon the effective length of any particular tonearm. The markings are labeled with respect to the P2S distance, not with respect to the actual pivot to stylus distance, which I find confusing if I have not used the protractor in several months. For example, if P2S (pivot to spindle) is 230mm and effective length (pivot to stylus) is 245mm, you adjust the cartridge so the stylus falls on a dot labeled "230mm". Weird but correct for mine, so far as I can tell. Then the next step is to rotate the disc template so that the stylus tip will fall on a dot confined by the innermost of two grids. You want to hit the dot and align the cartridge edges with the grid lines. Ideally, you are aligning the cantilever, if you can see it. You are essentially done at this point, as Simao suggests, but to maximize accuracy, for step 3, you rotate the disc again so that now the stylus tip falls on a dot within the outermost grid lines. This is kind of a test that you didn't disturb P2S in step 1. I don't know how different is the newer version from my older version to use, but I find mine to be quite versatile.
