Digital Electronics Status 27 Oct 2005 – 4 Nov 2005

Digital Electronics Status 27 Oct 2005  4 Nov 2005

Toney Minter reported a spectrometer problem last Sunday. The symptom was that a series of 58 lags from the last spectrometer quadrant had obviously bad values. Rich came in a trouble-shot for 3 hours Sunday evening during a VLBI run and determined that it was not an LTA problem. He was then displaced by a spectrometer run which did not need the last quadrant. Trouble-shooting continued on Tuesday during maintenance. Eventually a bad chip was found on the System Monitor board. After the later troubleshooting session, a test cable was left connected to a spectrometer input. It took a while for support staff to discover this…sorry!

Toney Minter reported a spectrometer problem last Sunday. The symptom was that a series of 58 lags from the last spectrometer quadrant had obviously bad values. Rich came in a trouble-shot for 3 hours Sunday evening during a VLBI run and determined that it was not an LTA problem. He was then displaced by a spectrometer run which did not need the last quadrant. Trouble-shooting continued on Tuesday during maintenance. Eventually a bad chip was found on the System Monitor board. After the later troubleshooting session, a test cable was left connected to a spectrometer input. It took a while for support staff to discover this&sorry!

Software Status -- Nicole

Software Status -- Ray

Single Dish Development #147 - Friday, November 4, 2005

Today ends week 5 of C7 2005 (a 6-week cycle). The Plan of Record for C7 is available from the wiki at PlanOfRecordC72005 and shows the status of all the items scheduled for work this cycle.

• CCB work is now in general support mode.

• Penn Array FITS archiver: IRC and MarkIII CVS tag in place, PAR code tagged/released with installation instuctions on the Wiki.

• PTCS: Changes to dynamic corrections are complete. Additions to antenna coordinator almost complete. (Still needs final check routine.) Currently running on simulator testing the interface changes.

• The Config Tool modifications for use of GASP and/or SPIGOT without BCPM are complete and awaiting integration tests.

• Work continues on the new version of GBTIDL and the 3mm receiver.

• Operational support for this week included:
  • Aided in determining odd spectrometer logfile entries when in A4 mode.
  • Investigated claims that SDFITS was runing slower than usual (affecting GBTIDL online). We concluded that the recent changes to SDFITS were not responsible for any slow-down, but that SDFITS is markedly inefficient while gathering calibration and other data before data reduction.

Digital Electronics Status 27 Oct 2005 – 4 Nov 2005

***Operations, Problem summary***

Toney Minter reported a spectrometer problem last Sunday. The symptom was that a series of 58 lags from the last spectrometer quadrant had obviously bad values. Rich came in a trouble-shot for 3 hours Sunday evening during a VLBI run and determined that it was not an LTA problem. He was then displaced by a spectrometer run which did not need the last quadrant. Trouble-shooting continued on Tuesday during maintenance. Eventually a bad chip was found on the System Monitor board. After the later troubleshooting session, a test cable was left connected to a spectrometer input. It took a while for support staff to discover this…sorry!

***Development***

Cal-Tech Continuum Backend (CCB):

The power supply for the CCB was completed and tested.

RFI tests of the CCB were conducted. After minor modifications, it passed with about 11 db to spare, assuming 40 db of shielding from the receiver room.

Software modifications and documentation continue.

The CCB is now up and running in the equipment room for last minute tests and evaluation by our software group and Martin Shepherd.

***Plans***

The CCB will be installed on the GBT during the full maintenance day next week.

Not much to report this week except that Melinda and I did a bit more testing on multi-backend configuration MR. It all looked good and so I signed off on it. Tons of Spigot observations are coming up in the next couple weeks which should give us lots of tests for control of SPIGOT+GASP (at least) with astrid.

This week was the first full week of 43m operations. We tracked spacecraft from 10:00 AM to 3:00 PM EST for four days. The 43m operations went well.

During the operations time, we also helped Frank Lind and Phil Erickson from MIT/Haystack observatory install two additional experiments at the 43m. One experiment will use signals from the 43m. The second, completely independent experiment will use signals from 6 phased antennas that are being erected near the MIT/LL trailer.

We anticpate operations next week from Tuesday through Thursday. We will not track on NRAO holidays.

We supported 12 projects in 28 observing sessions -- six of the observing sessions were VLB runs. The telescope was also scheduled for 13 hrs of Ka-band commissioning, 11 hrs of software tests, 8.5 hrs of maintenance, 7 hrs of receiver tests, and 1 hr of program checkouts. Average setup time for all but VLB sessions was 16 minutes.

Lost time was 5.6 hrs, about 4% of the time scheduled for observations and hardware tests. Lost time was due to:

• L-Band refrigerator : 1.5 hrs
• Antenna Manager / Msg Mux : 1.1 hrs
• Scheduling -- sort not yet up, source had set : 0.9 hrs
• Spectrometer - hardware and wrong cabling : 0.8 hrs
• SDFits Filler : 0.6 hrs
• X-band refrigerator : 0.5 hrs
• Astrid : 0.4 hrs

It looks like the work on Astrid has paid off. We had only two reported instances of Astrid problems and the reported lost time was about half of what it's been for the last few months.

Operational Issues:

A routine refrigerator replacement for the L-band receiver had problems when the replacement refrigerator seized up during cooldown. That was resolved the next day. And, the X-band receiver warmed up spontaneously. That refrigerator is being serviced on Friday.

Some of the Sigma-Tau maser redundant power supplies have failed; replacements will hopefully be installed on Friday.

Development:

Q-Band:

-- Completed first round of mixer tests over a frequency range of 38-50 GHz. These tests indicate that although they can be operated without DC Bias (as is currently the case on the GBT), lack of bias does affect the mixer's bandwidth. The next planned measurement is to use Labview software written by R. Norrod that controls the Anritzu network analyzer and uses it as a signal source. Our goal is to extend the data to 52 GHz.

-- J. Bauserman is building a copy of one channnel of the receiver using spare parts. We received one amplifier from Charlottesville. I'm trying to get a date for delivery of the second amplifier (I have been told it will be "soon").

-- Started design of a circular transition to mate an isolator to the input of a septum polarizer. This should provide a broadband termination for insertion loss and axial ratio measurements.

Gary (November 3, 2005)

R. Norrod 3 Nov 05

*We have received a quotation on base plate manufacture and welding. Negotiations will be necessary on terms and conditions and costs. We need some clarification.

• An extension was granted to obtain a bid on wear strips as well.
• Harry, John Shelton, telescope mechanics, and plant maintenance folks have been preparing and pouring foundations for surveying monuments. This work will continue.
• We had an onsite visit with a company to discuss support for project management, contractor inspections etc., and another one is in progress in Charlottesville during the commissioning meeting.

Last Week =====

Observations for proposals GBT05C-009, GBT05C-051, GL028 , GBT05B-042, GBT05B-032, GBT05C-049, GBT05C-034, GBT05C-001, GBT05C-057, GBT05C-046, GBT05C-014, GBT05C-015,

Completed proposals GL028

Next Week ===== Observations scheduled for ** GBT05A-041 [F ] Paul Demorest Precision Timing of Binary and Millisecond Pulsars GM057 [F ] Jon Marcaide Monitoring The Different Expansions Of Sn1993j At 6 And 18cm GBT05C-020 [ P ] Tony Remijan Confirmation Of Interstellar Methyltriacetylene (CH3C6H) Toward Tmc-1 GBT05C-042 [F ] Scott Ransom Timing the Binary and Millisecond Pulsars in NGC6440 and NGC6441 GBT05A-011 [F ] Scott Ransom Timing of the Binary and Millisecond Pulsars in Terzan5 GBT05C-002 [ B] Dain Kavars Extended OH Emission Maps of HISA Clouds GBT05C-057 [F ] Regina Jorgenson Search for 21cm Absorption toward Radio Loud, Extremely Optically Faint Sources GBT03C-012 [ P ] Jim Braatz Follow-Up Observations of Extragalactic H2O Masers Discovered with the GBT GBT05C-014 [ P ] Katie Devine Ammonia and CCS Observations of GLIMPSE Infrared Dark Clouds GBT05C-049 [F ] Dan Stinebring Follow-on scintillation observations of two pulsars GBT05C-007 [ P ] Tony Remijan A Search For Interstellar Cyanoformaldehyde (CNCHO) GBT05C-009 [ B] Gilles Joncas GBT HI Observations of the DRAO Deep Field: Determining Foregrounds for Planck ** Scheduled as F-ixed, P-rimary, B-ackup

Contact Information for 11/17/2005 - 12/01/2005 =================================== Proposal PI Bands Email [NRAO contact]

Scheduled hours [backup] ==================== Category/Month-> November December January Astronomy ~ 439 [154] 427 [264] 427 [282] Maintenance ~ 35 [043] 23 [060] 43 [060] Test & Comm ~ 188 [016] 134 [020] 120 [021] Shutdown ~ 36 36 0 Un-assigned ~ 22 126 155

Proposal Checkouts ============== Awaiting checkout - 0 Active checkout - 8 On Hold - 10 Schedule - 68 Completed - 403

Current backlog [hours prior to 05C*] = 765 [2001:44(1), 2002:91(3), 2003:36(3), 2004:267(12), 2005:327(20)] Total time to discharge [hours] = 2458 * Includes projects that are on hold for trimester 05C

%META:TOPICINFO{author="JohnFord" date="1130782080" format="1.0" version="1.1"}% %META:TOPICPARENT{name="CommissioningMeetings"}%

GBT Operations & Commissioning Meeting

04 November 2005

AGENDA

• Az Track, Antennae Report -- Bob
• Observing News -- Ron
• Scheduling Status -- Carl
• Microwave Electronics Status -- Roger
• Digital Electronics Status -- Rich
• Software Status -- Nicole
• Change Control Committee -- John
• Pulsar Related -- Scott
• MIT/LL 43m Project -- Glen
• Any other Business

Az Track, Antennae Report -- Bob

Observing News -- Ron

Scheduling Status -- Carl

Microwave Electronics Status -- Roger

Digital Electronics Status -- Rich

Software Status -- Nicole

Change Control Committee -- John

• Computing items
  • RHEL and M&C testing
    • A general discussion of how to move forward to get all Linux systems in the GBT to the latest rev. Generally, we will start with non-GBT computers, then GBT computers running standard hardware and device drivers, and finally, move on to computers with BIT-3 and EDT cards in them. The vortex replacement can be done before the last stage, but after the first 2 stages.
• Review of minutes from last meeting
  • Minutes were dispensed with.
• Continuing discussions of requests
  • New list of requests
    • None
  • Review of observing reports items (CurrentObservingReports?) and operator log items
    • L band warmed up
    • IF power drops in K band
    • L band noisy
    • Antenna Manager faults
    • Astrid/Turtle faults
    • Datacapture fault
    • Spectrometer problem
  • Review of MR's for this cycle
    • Data Quality checks on Ka Receiver FITS files. APPROVED
    • Config Tool support for CCB APPROVED
    • Config Tool support for PULSAR multi backend configurations APPROVED
• Other business
  • Cycle 8 planning meeting and request deadlines are looming. Reminder that only maintenance and critical patches will be scheduled this cycle for the software development division.
  • Richard will talk with Chris Clark about starting a System Infrastructure Reliability Improvement project to address system-wide issues related to compuing infrastructure, such as machines, netowrks, configurations, etc.

Pulsar Related -- Scott

MIT/LL 43m Project -- Glen

Any other Business

-- JohnFord - 31 Oct 2005