Choosing between 10k and 100k ohm potentiometer

[Infinity]

I've been told that a 10k (linear taper) potentiometer works well for measuring roll in a yoke. Boeing for example. But then I've also read Ian's document on the nosewheel steering and he used a 100k potentiometer. I would think the two ideas would use the same pot because they are basically doing the same thing. What reason(s) would there be for the large ohm difference in these two examples??

[jonesthesoftware]

Biggest difference is the amount of current each pots passes. If you are using the pot as a "joystick" type input to FSX then windows will scale the pot position regardless of it's full scale value as long as it draws enough current for the circuit board you are connecting to to be activated. The other difference is that of resolution. e.g 1/2 turn of a 100k pot has a 10 times greater change in actual resistance than 1/2 turn of a 10k pot but again this also relates to the resolution of your electronics card you are connected to. 10 bit(1024) or 12 bit(4096).
BUT......You can forget all this just connect a LINEAR pot between 10K and 100k, go to windows joystick calibration and calibrate for the full travel of your yoke( NOT the full travel of the pot), then go to FSX and assign that joystick movement to your yoke. Job done!
You can of course do even more fancy tuning if you use FSUIPC but that's another story.
regards
geoff

[Infinity]

Ah, thanks Geoff. So in theory, a 100K would be more precise, but that still wouldn't matter in the grand scheme of things because the differences would go away once it is calibrated.

So to recap, stay between 10k and 100k and I'm fine...right?

[jonesthesoftware]

Yep 10k to 100k LINEAR not log and you'll never know the difference once you calibrate via windows.
regards
geoff

[Infinity]

Awesome. Thanks!

[hyamesto]

By experience:
The 100k are very sensitive to electrical interferences.
The 10k potentiometer are best.

And if you plan to locate the pots far away of the inputs of your interface, you need shielded cables for connections to eliminated unwanted false values inducted by electrical interferences of other equipments (monitors, power supply, relays, etc.).
A good shielded cable is audio microphone balanced cable (two insulated wires, with an external shield, with a plastic or rubber tube outside. (There is an excelent american made cable, but i´not remember the brand)
Sorry if my english is not good.
Regards.

[Infinity]

Excellent point