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Tonearms with no anti-skate adjustment

I am in recent possession of a Grace 704 uni-pivot tonearm, which has no anti-skate adjustment. This is not optimal IMO, but should I really be worried?
128x128jdjohn
dover
2,265 posts
 
@lewm 
@cleeds 
If you put your thumb on the cartridge end of the tonearm and move the back of the arm up and down ( like VTA adjustment ), the counterweight tracks an ARC realtive to your thumb.
The point I made was that If the arm starts at level then the centre of mass is the furtherest from your thumb. Moving the back of the arm up and down at the back will move the centre of mass forward towards the mounting position because the counterwieght moves in an ARC.
Therefore IF you start with a level arm, the VTF will increase with either up or down motion because the centre of mass moves towards the cartridge in both instances.
 If you cant follow this then I cant help you any further, sorry.
moonglum
619 posts
 
Dear HDM,
Brilliant post! I didn’t even know this one existed!
I know Werner from PFM and he is a very good guy. His knowledge of electronics, digital & analogue, is even more impressive.

What is interesting about his measurements is that that the “underslung” COG examples all show the VTF increase, which is basically what we’ve been arguing about.
Cheers!

moonglum
619 posts
 
Cleeds,
It is not quite clear what you are saying here...
You are the only person so far who claims to have measured it and obtained the result you describe.
Was this a recent measurement i.e. did this phenomenon happen on your current system? If so, please supply details e.g. stylus gauge model, expected VTF, actual VTF, tonearm pivot displacement below normal (rough estimate is fine), tonearm/cartridge used etc.
If you can’t clearly remember don’t worry, just guess. No stress.
Kind regards,

Ag insider logo xs@2x
cleeds
6,030 posts
 
dover
... if the arm starts at level then ... Moving the back of the arm up and down at the back will move the centre of mass forward towards the mounting position ...Therefore IF you start with a level arm, the VTF will increase with either up or down motion because the centre of mass moves towards the cartridge in both instances ...
That’s a fanciful theory. Why don’t you try and actually perform this test and measure the result? If you do, you’ll find your theory is mistaken. It’s as simple as that.
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