Magnetic suspension linear-tracking tonearm?

[Shaun]

Is such a thing possible? Seems to me that it would solve the problem one has with air suspension arms of having to provide an air supply.

Shaun

[Steve Eddy]

Originally posted by Shaun
Is such a thing possible? Seems to me that it would solve the problem one has with air suspension arms of having to provide an air supply.

The problem would be one of stability. Do a Google on "Earnshaw's theorem."

se

[stelios]

see here:

http://www-hfml.sci.kun.nl/fingertip.html

and here :

http://scitoys.com/scitoys/scitoys/m...uspension.html


have a try and if you're successful (it looks easy) let us know


s

[Steve Eddy]

Originally posted by stelios
see here:

http://www-hfml.sci.kun.nl/fingertip.html

and here :

http://scitoys.com/scitoys/scitoys/m...uspension.html


have a try and if you're successful (it looks easy) let us know

Both of those involve diamagnetism. Problem with that is that even the most diamagnetic material known (bismuth) is still very weak. You'd have to produce one hell of a strong magnetic field in order to keep anything of any appreciable mass suspended. It's all they can do in these experiments to keep the bismuth itself suspedned.

But if one were able to produce a sufficiently strong magnetic field, technically it's possible. But keep in mind that a phono cartridge is a magnetic device which will be effected by any stray magnetic fields.

se

[Havoc]

Read the article! They let the magnet float, and use graphite, no strong fields.

[Steve Eddy]

Originally posted by Havoc
Read the article! They let the magnet float, and use graphite, no strong fields.

What do you mean no strong fields? They're using very powerful neodymium iron boron magnets. And they're also using additional compensating magnets.

Graphite and bismuth are so weakly diamagnetic that they're only going to cancel just a very tiny fraction of the stray fields produced by the magnets.

se