Potential Problems

A problem which is due to the DAS itself can usually be identified by bad baselines on only one subband. Slopes, sine-waves and generally poor baselines across more than one subband are most likely due to the IF or frontend receiver. The following describe some of the problems we have occasionally seen during the first 2 years of regular use of the DAS. Please e-mail or contact JCMT personnel if these or other problems are encountered, preferably with the scan numbers and directory.

• Subband gain differences
• Ringing
• Problems loading the DAS
• Generally poor baselines in one subband
• Quick fix for DAS baseline errors