[RodB]

It's been a long while since I used mine, but just the other day I got it back out of the shed to sort out again. What I remember is that If you look up the cartridge spec there will be a tracking weight (like 0.75 to 1.5 grams). Balance the arm as advised then add the amount of tracking weight, which should be in this range and will depend on how the arm responds, given it's support and mass. Lightest gives least wear of record, but requires good tracking, the deck manufacturer might state minimum tracking weight if you have this info. With the brush in place you should add 0.5 gram to this. Hopefully also within this range..

Hope this helps...