The RSS cryostat's been back at the hospital it was born in - the CCD lab at the SAAO in Cape Town.
We've been struggling with intermittent bias problems that were traced to the pre-amp. Since this is really risky to work on, it was best to remove the cryostat from the telescope & send it down to CT for repairs.
>15 years of living wild on the very top of the telescope have not been kind to all of the bits & the corrosion's particularly bad on the cryocooler lines where lots of condensation forms.
One of the major projects on the go within the SAAO Instrumentation group is the development of a new RSS detector system, to replace the 3 x 2K x 4K array of chips with a modern, monolithic 6K x 6K CCD. The obsolete SDSU II CCD controllers that are currently in use will be replaced with the IDSAC controllers developed at IUCAA (one of the SALT partner institutions). But this project is more than a year from completion so we need to take extra special care of the current system in the meantime.
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| Pieter & Kathryn pondering the vagaries of electronics |
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| A key piece of test equipment was a can of Freeze 75 used to temperature stress misbehaving components |
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| The middle board had some unhappy places so it's been replaced |
The cables were also all checked & the cryostat window got a clean. The whole lot's ready to go back to the telescope asap, so we'll ferry it up there tomorrow...
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