rcd@opus.UUCP (Dick Dunn) (04/28/84)
<> The article to which this is a followup had the correct title (see) but unfortunately it's a little off target itself. >In theory, there should be no skating force present when an ungrooved >portion of an LP is played. Skating force originates because of the >oblique angle of an articulated tone arm (and therefore stylus) with >respect to the cutting angle of the groove. Setting anti-skating without >the stylus in the groove (to produce the skating force which you are trying >to counteract), is useless. Skating force originates because of the angle at the end of the tonearm, but it's unrelated to the angle of the stylus wrt the groove. The slight angle of the stylus away from tangential is called tracking error; it's what the "bent" tonearm design is intended to reduce. Although the bend in the tonearm helps stylus alignment, it misaligns the tangent to the record with the pivot of the tonearm - THAT's where the force comes from, and it will be there regardless of the presence of a groove. However, it is true that the amount of force differs somewhat with a groove present - in fact, it differs depending on what's in the groove! (Music generates slightly more skate force than a quiet groove.) You can convince yourself that the stylus/groove misalignment won't generate the skating force - remember that tracking error varies either side of zero. At the outside groove the stylus is misaligned in one direction; at the inside it is misaligned the other direction, so tracking error changes sign. If tracking error determined skate, skate would change sign also. -- ...Cerebus for dictator! Dick Dunn {hao,ucbvax,allegra}!nbires!rcd (303) 444-5710 x3086