There are many types of tone arms with all kinds of adjustment systems but they usually fall into 3 types.
1) Tone arms with 3 adjustments:
counterweight
anti-skating
weight
These are adjusted by:
Setting the anti-skating adjustment to zero
Setting the counter balance weight so that the tone arm floats in mid-air over the record surface.
This may take several tries to get it to not rise or fall.
Set the weight indicator ring to zero
Set the weight control to the weight (in grams) recommended by the cartridge manufacturer.
Set the anti-skating control to the same value as the weight.
2) Tone arms with 2 adjustments:
counterbalance
weight
These are set up the same way as above but without the anti-skating adjustment
3) Tone Arms with 1 adjustment
These may have only a counter balance weight or a weight control. they are set so that the cartridge has the correct weight.
Many tone arms may not be calibrated in grams or have any calibration marks at all.
A tone arm scale (available at Radio Shack) can be used to help get the weight correct, or check the calibration marks.
Good Luck!
