Thursday, May 19: On Tuesday we finished raising the new reflector screen on the west main array. This included adding springs to help maintain an even tension. We found issues at altitude on four poles in the east array. We wound up replacing 3 baluns and one resistor box. At antenna #8 we found more dramatic evidence of a lightning strike - an incinerated 75 W power resistor. On Wednesday went through the west main array with Dennis aligning the poles by cutting and tensioning guy lines. We noticed that the N-S guys on the other arrays had slackened and we went though those as well re-tensioning and cutting where necessary. It was noticeable that the east arrays - which catch more of the prevailing winds across their lengths - had slackened more than the west interferometer array. Kevin and Kessie installed replacement Minicircuit amplifiers in a number of boxes and made some other repairs. Mike and Evan tracked down remaining antenna site issues at ground level. As of Thursday morning we are running on full sets of tx and antennas. The work has shifted indoors in time to get us out of the cold drizzling Kansas rain. We are testing the box-by-box performance.
Tuesday, May 17: After much hard work we are seeing the upper reflector wires being strung tight across the west main array. Dennis and Josh are battling strong winds at altitude to attach the springs. Worse weather is expected; we are pressing to get as much of the outside work done today. Monday was great and we made excellent progress to reach this point. A few other issues around the arrays have received attention. Sunday, May 15: The crew got in to Hays about 9:30 pm after a difficult start. Our flight from Chicago to Wichita was cancelled and our departure from Charlotte rescheduled for late Monday. After a tense hour at the USairways counter we *just* managed to catch a direct flight to Kansas City instead. We detoured to Wichita to pick up Kessie, our South African visitor. Reveille is tomorrow at 7 am to meet up with the contractor at the site by 8 am.
Prelim: It is again time for a team of valiant SuperDARN warriors to launch a campaign against the forces of nature that act to degrade radar performance. Prof. Mike Ruohoniemi, Engineer Kevin Sterne, and Graduate Student Evan Thomas from Virginia Tech will travel to Hays, Kansas on May 15, 2011 to repair the West Radar Reflector array and conduct additional radar maintenance. Engineer Kessie Govender of South Africa will also be joining the Virginia Tech team for this trip. Unlike the famous general pictured to the left, the team conducting this campaign anticipates a safe return home on May 27, 2011.
Maintenance Trip to the Kansas Radars Completed!
By: Mike, Kevin, & Nathaniel on: Sun., May 15, 2011 10:18 AM EDT (8074 Reads)
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Friday, May 20 pm: We made a good finish today at the site. Kevin and Kessie completed the work on the lightning arrestors. We added a few more hog rings to the eyenut connections on the rebuilt reflector screen and replaced the ground connector at E#16, which had been giving us fits. That seemed to clear up the last issue in the way of having all boxes working on all antennas. The data display looks good. Kevin made some IF/RF measurements requested by Ray. We walked the new FHSU intern, Randy, around the site. Randy is a geography student and works with Prof. Heinrichs on the weather station at the site. He provided the wind records that confirmed the cause of the reflector screen blow-down a year ago. His first official function was to take this picture of the VT crew framed by the nexus. Tonight we are in Wichita. All but Kevin ship out in the morning. Kevin will attend an IEEE conference in Kansas City next week. He is presenting a poster on the TTFD antenna that is drawn from a paper that has been accepted for publication by the IEEE.
Friday, May 20 am: We had a bad turn yesterday when strong gusty winds came up around thunderstorms that passed through the area. One of the newly tensioned back reflector guys popped where it had been crimped near the eyenut at the base of the pole. As we watched, the entire array would sometimes start a side-to-side oscillation centered on the pole mid-points with the loose pole serving as the point of access for wind energy. We had several such episodes. The original set of 3 hog ring crimps to hold the kevlar cable steady at the eyenut was not sufficient as several more guys popped with the wind gusting from the south. We set about reinforcing the connection with many more crimps. Meanwhile, Kevin and Kessie are moving through the arrays mounting lightning arrestors. On campus we called on John Heinrich, said goodbye to Mark, and corrected a slow wireless connection by rotating the antenna unit back to alignment, by 90 deg! The VT Crew: Kevin Sterne, Evan Thomas, Mike Ruohoniemi; from HMO (South Africa) Kessie Govender, FHSU (Hays) - Mark Garrett |
