1.9m

Cassegrain Spectrograph

1. Readout issue in 1x2 binning – Occasionally when reading out a 1x2 image, the spectrum is shifted down the CCD by ~65 rows. When this happens, you will notice the following in the image on the spectrograph control software: The red readout bar to the left of the image extends below the bottom edge of the image display On-sky, the target spectrum is shifted down the CCD toward the bottom of the image On an arc, there are no arc lines in the top ~1/3 of the CCD, but they continue to the bottom edge of the image. To remedy, take e.g. a bias in 1x1 and let it readout. Change the binning back to 1x2, take a bias and check that the red readout bar does not extend below the bottom of the image. If it does, revert to 1x1 and repeat.

2. Filter Wheel – It is necessary to initialise the filter wheel before changing filters; do this every time as follows: In the Spectrograph Control Panel, click the “Util” button in the top left corner. In the pop-up Utilties window, click Filter Wheel “Init”. In the Filter Wheel section of the Spectrograph Control Panel, ensure that the green indicators are lit for both “Ref” and “Centered”. If not, repeat previous step but click “Reset” then “Init”. Select the desired filter and click “Go”.

Giraffe

1. Filter Wheel – Always initialise the filter wheel before changing the filter.

Date: RA zeropoint (s): Dec zeropoint ("):

Date: Guide mirror in beam: Guide mirror out of beam:

Date: Guide mirror in beam: To view star on fibre, move XY slides to x=590, y=-12900 (guide mirror out of beam)