Using techniques developed by Mike, the performance of the RA gear is shown below. This is the images of a star on a SBIG ST-237 CCD Camera taken every XXXX seconds with an exposure of YY seconds. The CCD camera is rotated so that the CCD array is lined up with Declination on the Y -axis and RA on the X-axis. The left axis is scaled to arc seconds. The bottom axis is the ordinal number of images taken.

Figure 1

You can see many different components from low to high frequency. This data is difficult to interpret so Mike performed Fourier analysis of the data to yield

Figure 2

From left to right the peaks are:

• An unknown very low frequency component,
• Periodic error of the main gear and its worm at 1/240 = 0.0042 Hz (Once every four minutes which is the worm gear's rate)
• Unknown peak,
• A very strong vibration at about 3 times the periodic error frquency (but not exactly 3 times).
• The rest seem to be of little consequence.