[Comm2011] CCD # 92

[K Kuijken]

Looking at a few images from last night: the problem is in CCD 93, not 
92. So one of the ones in our troublesome quartet.
Olaf, we have all the data here - let us know if we can help with any 
analysis.
Konrad


Olaf Iwert wrote:
> Hi Dietrich,
>
> Yes, I already thought about these points yesterday and verified them
> today.
>
> Before we draw more conclusions we need however more info from Paranal
> (like you said) and an assessment what works and what does not. At this
> point it could be caused by almost anything inside the amplifier and
> video chain: cables, bias voltage, video board......
> Nevertheless of course it distracts me from thinking normally, as it is
> not normal and we never saw something similar.
> When I called yesterday, noone had had time to look at the problem, due
> to other emergencies.
>
> Some answers to your questions:
>  From all information I have (not much) #92 is the correct number.
> # 92 did not show any previous problems.
> In the worst case replacement device could be Chamaeleon, but this
> device has flatness problems and is also no ideal fit to the channel
> potential. This is all we have.
> # 92 is not from a batch, where the protection diodes have been removed.
> # 92 is not in the mixed voltage group.
> # 92 is neither inside the group showing crosstalk, nor in the same
> group where we exchanged the faulty CCD in 2009.
> All spare devices are on Paranal.
>
> With best wishes
> Olaf
>