How does a 3 pole audio pot work?

[Carnesd]

So I've got a bad pot in my cheapy boombox,  I removed it but can't seem to find a replacement with the same dimensions and I don't know the resistance either.

Id like to just set it to a certain volume so I'm thinking just to wire it up with a couple resistors and figure out the correct resistance to get the volume I need.

Problem is I'm not too sure how to wire it as its a three prong almost exactly like this one:
http://www.mouser.com/ProductDetail/ALPS/RK09D113AF25A55/?qs=sGAEpiMZZMsV8lMX1HNLj7GAXoAKleXf

I know I will have to figure out the resistance but i've got a ton of resisters i can try. 

So how would I go about this? 

 

[kepeb]

depending on how cheap it is i would just mount another pot somewhere else on the case.
also, i wouldn't think your going or accuracy with an exact replacement. try a 100k, 500k or 1m if you have them in there and ave a listen while you turn it.
only major other difference might be if its linear or log (commonly volume) pot. but thats probably not an issue i you were gonna use resistors either.

 

[Carnesd]

I guess I could just run wires to the pot and mount it outside the case, but I'd still have to figure out the resistance that will work,

So with three poles where would i put the resistor?

 

[abechap024]

Hi,
Common potentiometers, like the one you took from your boombox, have the "wiper" part on the middle pin and the ends of the resistor on the two outside pins. You can take a ohms meter and measure from the 2 outside pins and that will give you the value of the poteniometer. IF its scratchy you might be better off cleaning it with some contact cleaner...

otherwise...happy experimenting....

try looking at some data sheets for potentiometers...lots of information on data sheets

 

[Carnesd]

Ok, so to just try a resistor,  I should put my resistor in between the middle pin and the pin hole that goes to ground correct?

 

[abechap024]

no your going to need 2 resistors. Think about how a pot works. the wiper essentially splits the resistive trace in half. when the wiper is turned the resistance between the wiper and pin 1 (for example) goes down and the resistance between the wiper and pin 3 goes up.
unless the wiper is at it extremes it returns 2 values of resistance that you would need 2 resistors to emulate.

AC

 

[Carnesd]

ok,  so if I've got say a 10k pot and I want to replace it with two resistors,  and I would like full volume,  I would put something close to 10k on one side and short the other? or the opposite way depending on how the pcb is wired.
Sorry for my noobishness.

 

[jdbakker]

if I've got say a 10k pot and I want to replace it with two resistors,  and I would like full volume,  I would put something close to 10k on one side and short the other? or the opposite way depending on how the pcb is wired.

Exactly.

(In almost all cases you can even leave the 10k resistor out if all you want is full volume. Then again, there are a few situations where the pot resistance either provides DC bias to one of the stages of the amp, or the loading by the pot changes the sound of the circuit, so without seeing the full schematic the safest bet is to leave the 10k resistor in there).

JD 'http://en.wikipedia.org/wiki/Potentiometer' B.