Need help with anti-skating on Technics SL-1210GR

Do NOT use blank record, use music or use Hi-Fi News TEST LP
Set anti-skating equal to the tracking force or lower (it depends on the stylus profile).
Level your turntable first of all.

Make sure the armtube is parallel to the record surface when the needle is in the groove 

Thanks for the tip on the TEST LP. The TT is perfectly level and the armtube is parallel to the record surface. Do you think a mis-aligned cartridge or incorrect overhang could cause this behavior? I used the protractor but it's not always easy to tell when you have it right.

If you are doing the SoundSmith end of record test, which is valid, there should continue to be a slow movement toward the spindle.  To completely stop that movement would require an excessive amount of anti skate.  Beware of some of the test records as they can also cause you to over due the setting.  Setting the final position by ear ultimately will be a technique you should research and practice. 

Hi-Fi News TEST LP is the best you can use, this is a must have record, you will get protractor with this LP. You can measure tonearm/cartridge resonance frequency with this LP. Buy it, it will help you with everything.

Do not add too much anti-skating, you can start with zero, you can add half or make it exactly as the tracking force.

There will be a force that moving the arm toward the spindle.
When the arm is balanced and there is no tracking force you will see it will move slowly from the spindle to the edge of the record direction.

All you need is to compensate a bit when the needle is on the spinnin’ record.

If the tracking force is low the anti-skating must be set to the minimum (no more that tracking force).