Steve, one of the nice things about a linear tracker is that for test purposes you can induce constant tracking error in a controlled and calculable manner through a small change in overhang. With my tangent arm I can clearly hear the difference of an induced .5 mm deviation off zenith, as illustrated in the second graphic at:
http://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=1010339&highlight=Dave+Garretson&search_url=%2Fcgi%2Fsearch.mpl%3Fsearchtext%3D%26b%3DAND%26topic%3D%26topics_only%3DN%26author%3DDave%2BGarretson%26date1%3D%26date2%3D%26slowmessage%3D%26sort%3Dscore%26sortOrder%3DDESC%26forum%3Dvinyl
If this small granularity is perceptible, then so much the more so for the much wider range of errors of a 9" arm as shown in the first graphic. The case is not much different for a 12" arm.
No flame retardent suit is necessary.
http://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=1010339&highlight=Dave+Garretson&search_url=%2Fcgi%2Fsearch.mpl%3Fsearchtext%3D%26b%3DAND%26topic%3D%26topics_only%3DN%26author%3DDave%2BGarretson%26date1%3D%26date2%3D%26slowmessage%3D%26sort%3Dscore%26sortOrder%3DDESC%26forum%3Dvinyl
If this small granularity is perceptible, then so much the more so for the much wider range of errors of a 9" arm as shown in the first graphic. The case is not much different for a 12" arm.
No flame retardent suit is necessary.