Re:microstepper drives

[jemian@arev.uni.aps.anl.gov (Pete Jemian)]

Mark Rivers wrote:
> ... The motors being microstepped were about 24' from our
> Si(Li) detector and I measured no difference in resolution of the detector
> with the Step-Pak powered on or off.  On the other hand, our 13' Sony color
> monitors had a huge effect on resolution, we have to turn them off when
> collecting data.

Is the effect caused more by proximity of the 
    detector to the motor
    detector to the motor driver (or source of chopping waveform)
    detector to chopping power supply
    amplifier to any of the baove permutations
?

I think the noise source is the chopping microstepper driver.
Noise could be radiated from the motor drive cable and picked
up by the detector antenna -er- cable.

Why do I think this?  When I turned off the offending driver 
(switched off the ACS SPD-3M card or switched off the 
Newport MD4 rack), the noise vanished.  Magical-like.

Pete