Re: [ARSCLIST] Mostly for laughs

[Don Cox <doncox@xxxxxxxxxxxxxx>]

On 23/10/06, Mwcpc6@xxxxxxx wrote:
> In a message dated 10/23/2006 7:11:22 PM Eastern Daylight Time,
> insuranceman@xxxxxxxxxx writes: I still don't know why the skating
> force makes the stylus pull IN. If it were some kind of centrifugal
> force, it'd be thrown outward (or at least my very limited brain tells
> me that). That's why I have four linear tracking arms--all various
> Rube Goldberg type contraptions. Phillip
> *******************
> 
> If you actually look at your turntable, you will notice that the tone
> arm is longer than the distance between the spindle and its pivot
> point.
> 
> You should also notice that the far side of the record from the tone
> arm is moving in a direction that will pull the tone arm toward the
> spindle.
> 
> Most of the time, depending on the exact geometry of the turntable
> setup, the stylus is on the side of the turntable that is dragging it
> toward the spindle.
> 
> This is what causes the skating force that is minimized by the odd and
> sometimes complex shapes and taken by tone arms to minimize tracking
> error. A radial tone arm and a recording lathe do not have tracking
> error or skating force. It can be adjusted to be inward or outward
> during parts of the record, but can't be eliminated with a pivoted
> tone arm.
> 
> All of this talk about centrifugal force gets rather tiresome after a
> while. 1950s Hi-fi magazines had endless articles about setting up
> tone arms and tone arm geometry to minimize tracking error and skating
> force. Tracking error can produce a small amount of distortion but
> skating force just produces a small DC offset to the position of the
> stylus and, unless extreme, in a poorly designed cartridge, has no
> effect at all.

And almost every arm has some kind of mechanism such as a thread, weight
and pulley to make the pressure equal on both walls of the groove.

As you say, it is not all that critical.

Regards
-- 
Don Cox
doncox@xxxxxxxxxxxxxx