Odd RA tracking error

[JohnH]

What could cause this behaviour in RA, this chart shows two worm cycles (each is about 8 minutes)....yes the clutch is tight, yes the mount was balanced. It seems repeatable, that is for half each worm cycle the tracking rate is in error....I guess an inspection adjustment of the RA worm/gear is in order...

[gbeal]

No too well balanced it is John? Consensus is a bit of "weight" on the lower side, so the gears have to work.
Gary

[JohnH]

Could be that I will try a bigger offset to make sure the motor is always under load....