bad precision pot?

[jorgen.bergfors at idg.se]

>I'll need to crack a spare one open and see what's inside.

You will probably find it identical to a single turn, except that the wiper is driven by a worm gear, instead of directly. This is if it is the vertical type with the setting screw on top.
The oblong type more resembles a slider. In this case the wiper has a nut that is moved by turning a screw. I suppose this type has slightly better settability than the vertical type. Any comments?
Of course the vertical type has the advantage that it has the same pin pattern as single turn types. So you can easily substitute them, without changing the board layout. Therefore I normally use this type.

/Jorgen