Totally confused with log pot calculation-Need 500K Sho-Bud pot

[aron]

hmmm, well, knowing that:

RT = (R1 X R2 )/ (R1 + R2)
for resistors means that for a 500K pot, the smallest tapering resistor I could use would be 500K if I wanted a 500K log pot.

Which would mean that if I wanted:

Tapering resistor Rt = R/b and for example b=6
then the resulting pot would have to be a huge value. Which in essence means I can't easily go out and simulate a 500K log pot.

Anyone know of a place I can get 500K log pots with long shafts and have it be conductive plastic (long life)?

I need a new pot for my Sho-Bud volume pedal.  Here's a question, for the volume pedal pots like Dunlop etc... can that plastic gear be taken off easily and if so, is the shaft round so I can put the Sho-Bud "collar" on it?

Thanks,

Aron

[aron]

I might try and buy one of those dunlop wah/volume pots and cut away the plastic gear. I just don't know if it's audio taper.