You should understand that any anti-skating force you apply will rarely be exactly the "right" amount. The spinning record pulls the stylus in a direction of a tangent to the groove at the point of the stylus. If the cartridge is restrained by the pivot of an ordinary arm, that pivot is inside the tangent and therefore does not pull directly back on the stylus. The sum of the vectors is a force toward the inside of the record, skating force, which you try to counteract with anti-skating force. The key point here is that the skating force varies with the pull on the stylus, which varies with the condition of the record, the shape of the stylus, the speed of the groove [which varies across the record], and the magnitude and frequency of the modulations of the groove. The anti-skating force is, by contrast, essentially fixed in amount [although there are ways of making it change, like using magnets]. Once you know that any amount of force will be the wrong amount a good portion of the time, you can avoid worrying about whether it is set just right. [One practical point: using a grooveless record, as some people do, is probably not a good approximation since there is probably less friction since the stylus is not in a groove. My guess is that you should apply a little more anti-skating force than the amount needed to stop skating on a blank disk.] Isn't analogue fun?
Anti-skating: how to set
I'd appreciate some help on setting anti-skating on a Rega 25 and an SME V. I have no access to an oscilloscope. I do have the Cardas "Sweep" record, which has areas of blank grooves that may be intended for (among other uses) setting anti-skating force with pivoted tone arms like mine. I did set anti-skating force that way, adjusting it until the cartridge remained stationary, moving neither in nor out. Can I have any confidence that this procedure gets it right?