This idea of "microing by eye" got me thinking and checking myself. On my soon to be gone table I noticed that when I clamped an Lp down that it tended to be biased toward the spindel, probably by at least 1/32 of and inch. So I changed the way I clamp using a bit less down force and adding an extra o-ring to the spindel. This cut the deflection about in half but there is still a bias toward the spindel. I'm doing crude, but telling, measurements with a very light weight bubble level. The point is that what could be seen as eye level could in reality be well outside .25 degrees. This situatioin that I experienced could be somewhat difficult to see because I'm trying to sight (site ?) along a slighty concave surface. About now I'm thinking I should bone up on the voltage reading method to find that "close enough to tune by ear" zone. Thanks to all for a great lesson.
Dan
