A counter weight is slid along the rear arm extension, and clamped when the arm is in balance. Then a spring tension is adjusted to add the required tracking weight. The tension control may be calibrated in grams, or an external balance may be required.
"Cristian, You recently transferred a quarter inch audio tape of my old college bluegrass band (The Tomcat Ramblers) into two CD’s. The original recordings were made using vintage equipment over 30 years ago. The tapes had been sitting in my hot and cold garage all this time, which didn’t help. When I got my CD’s back from you – I was ..."