I used this trick to measure my VTF last night and it works well. Now, if I only could find a way to determine if my arm is parallel to my table for VTA purposes. The only way I can seem to even get close is look at the angle between the front of my cartridge and the record when the needle is on the record. (i.e. don't look at the cartridge head-on, but from the side) I have a RB300 arm and I don't see how people can tell if the arm is straight, when we're talking about fractions of degrees... I tried to put my bubble level on top of my tonearm near the cartridge, but this didn't seem to give me an accurate reading... not sure why, but even though my table was level, the bubble-level on top of the arm wouldn't produce a level setting that "looked level"...