MDM Trouble Report for 2016 Jun 12

Telescope: 1.3m
Observer(s): Weil&Thorstensen (Dartmouth)
Instrument: Andor direct

Problem(s) Encountered:
The nodding has returned.

We set on a target around a half-hour west and at +14 degrees, 
and found the telescope bouncing by 30 arcsec or more in dec,
intermittently -- it would track ok for a few seconds, and then
start bouncing wildly back and forth in dec, pretty much 
exactly as it did with the old motor.  We took a timeseries
of it with the Andor.  The nodding was not seen by the
dec encoder.

We went to another target and the nodding disappeared - 
the telescope bobbled in dec for a minute or two during a long
time series, like it did last night, but it was generally
very steady.

As for diagnosis, I'm thinking that with an insensitive filter
like U, and short exposures, it may be possible to track stars
in broad daylight with the Andor -- it's worth trying, anyway.

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Submitted on 2016 Jun 13 [5:20:20]