Elizabeth Claire “Beth” Vanaman was raised in rural upcountry Maui and moved to Hilo in 2008. Despite her meager exposure to science during childhood, the bits of knowledge she did acquire inspired her to pursue a degree in Electronics Technology at Hawai‘i Community College. With a solid understanding of circuit-board design and troubleshooting, Beth plans to enter a four-year degree program and put her current skills into practice in the workforce, striving toward a deeper understanding of both the applied and natural sciences.

Institution when accepted: Hawai‘i Community College

Akamai Project: Troubleshooting Circuit Boards for the Digital Correlator of the SMA

Project Site: Smithsonian Astrophysical Observatory (SAO)

Mentors: Chris Schaab & John Maute

Project Abstract:

The Smithsonian Submillimeter Array (SMA), situated on the summit of Mauna Kea, includes eight antenna dishes and a digital correlator back-end — a large array of electronics that amplifies incoming signals and reduces noise by comparing signals between pairs of antennas. Each correlator is responsible for relaying, digitizing, and down-converting incoming signals from hundreds of GHz to just a few GHz, and it accomplishes this with a branching series of large circuit boards, each with its own processor. Given the large number of individual circuit boards, a systematic approach is needed to diagnose and repair boards as they fail. We have developed a troubleshooting method that begins by examining the faulty board’s output signal with a specialized display terminal. Once the problem is identified, schematic diagrams are used to pinpoint the computer chips that are most likely responsible for the particular malfunction. Suspect chips are replaced, and finally, the board is tested for full functionality. A handful of receiver boards have already been successfully repaired with this method and have been returned to service. Because of the complexity of the correlator electronics, keeping track of past failure modes and successful repair strategies is essential for troubleshooting boards efficiently in the future. As receiver board malfunctions and their repair steps are documented, a troubleshooting flowchart will be constructed as a clear guide to assist future correlator  technicians.