ortofon rmg 309 i

manual in japanese ....not english
sorry

https://www.ortofon.com/rmg-309-vintage-p-655

Also take a look on vinylengine.com to see if they have a manual there

thanks but it is not explained how to adjust the pring, it is not explained how to do dynamic balancing ...
It's useless,,,,,,

Dynamic balancing is not a "thing" you do, it's a design of the tonearm.

Long answer: a static-balanced arm is a simple counterweighted lever.  A dynamically-balanced tonearm still has to be statically balanced (more or less) but uses a spring or method to apply an inertia-damping force to the tonearm in two planes.  In general, static-balanced arms are considered by some to be superior for high-compliance cartridges and dymanically-balanced arms are consider (again, by some) to be of particular advantage to low-compliance cartridges.

Short answer: if your tonearm is a dynamically-balanced arm and it's balanced (VTF is set properly), then it's dynamically balanced.

I apologize for my unclear question,
I am aware that ortofon RMG309 is a dynamically balanced arm,
but I don't understand or don't know how to make it work properly ...
What is the spring used for above the bearing? and the counterweight behind is smooth.? the numbered ring? ..
in short, I need guidance from someone who has this arm and who does it work the best ...
thanks Luigi