Best Tractor

Hi Music Lovers!
Finally, I think I got very close to sweet spot with my AirTight PC-1 sitting on a Breuer 8C tonearm on a Raven One TT.
Using protractor were tracking line printed on a mirror with zero reference points seems easy at first sight.
It takes patience to adjust, we are talking about parts of a millimetre.
Yip has taken this into consideration and with a lot of photos for guidance, which are a necessity.
With adjust/listening, adjust/listening, adjust/listening......you´ll finally get closer to sweet spot. Without these good photos it would be difficult.
Well done Yip for an excellent manual.
Quote (with its wright)- It took some time but definitely
worth it.
Bear in mind, this protractor is custom made for your particular cartridge/tonearm set-up.
Wow... what a soundstage, really enjoy this.
It gives you a receipt how important proper set-up is.

BTW (on Breuer) does anyone know what adjustment knob below antiskating is used for?
My manual doesn´t say (simple sheet of paper).

Many Thanks!