> Info wrote:
>> the only thing it can be is
>> the wiper inside the pot.

Perhaps an experiment to see if the pot is actually going to high 
impedence....

1) Create a stiff voltage divider off the 24V supply to output say 4V.

2) Connect the output of the voltage divider to the wiper of the pot via a 
100K ohm resistor.

3) Disconnect the A/D and use a high-impendence (1M or better) scope to 
watch the signal.

4) Now if the pot (wiper) is apprpropriately low impedence the pot should be 
able to pull the scope input well away from 4V. If it goes transiently high 
impedence the voltage should jump toward the 4V created by the voltage 
divider. The closer it gets to 4V the higher the wiper impedence must be.

-- Bob Ammerman
RAm Systems

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