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{X} B100 out of operation for at least several days due to broken Gunn oscillator (RM 2005-11-22)  
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/!\ 1 MHz Filterbank not yet integrated in new control system (RM 7.12.05)

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TableOfContents(3)

System - General

/!\ The 30-m telescope is now operating using the New Control System (NCS) (2005-11-30 HU)

Some of the information below, especially about available observing features and problems, refers to the old control system (OLD CS). It will be updated soon.

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Antenna

(./) OK

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Wobbler

/!\ Observing configuration sometimes is not transfered to the wobbler control system and when fails W. Brunswig has to restart his communication programs (since January 2005). Wobbler config. can be set manually by operator (OLD CS)

Wobbler rotation implemented. Current range: +/- 60deg (2004-12-01 AW) (OLD CS)

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Pointing Model

heterodyne: OK (last model update: 2005-04-30 ). (OLD CS)

bolometer: OK (last model update: 2004-11-02 ). (OLD CS)

/!\ Operator/AOD: Check regularly that automatic P4 P5 is working (2002-12-13).BR {X} Narrowband continuum pointing (for SiO masers) is out of service! (2003-07-09, 2003-07-30)

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SIS Receivers

A, B, C and D receivers are aligned within 3", checked (2003-09-24)

/!\ Receiver C150 shows low continuum signal at the higher frequencies (>168 GHz) It has to be fully checked. Use D150 instead. (2005-11-16)

Calibration Tcold temperatures have been checked by receiver group. New scaling factor of 0.94 has been implemented into obs.(OLD CS) Obs Tcold should be OK (2005-06-28) (OLD CS)

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Pointing and Flux monitoring with SIS receivers:

Continuum instability ("ripple") can occur with all receivers, making pointing and focusing difficult.

  • In general some receivers are better then others in this respect as summarized here:
    • A100 generally OK for pointing. (2003-11-12) BR B100 OK, is best for pointing, but is out of operation (2005-11-30)! BR /!\ C150 often bad for pointing, ripple. (2002-07-16) BR D150 generally good performance for pointing.(2002-07-16) BR /!\ A230 often unstable, bad for pointing and flux monitoring. (2003-11-12) BR B230 OK BR /!\ C270 very bad for pointing at 265 Ghz. (2002-07-16) BR /!\ D270 can be unstable and difficult for pointing. (2002-07-16) BR

      HERA pointing difficulties using beam switch mode - total power mode gave better results but requires excellent weather BR Wobbler switching may avoid ripple, beamswitching is most sensitive to ripple

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HERA

Second polarization installed. /!\ One blind pixel. BR SSB tuning tables for standard frequencies. BR Sideband rejections not determined (2004-12-01 AW) BR

/!\ Watch the computer control of the derotator closely (2002-12-22). BR /!\ Make sure the derotator tracking is stopped after observations, i.e, set to zero degrees in "frame". BR /!\ With VESPA, the maximum of 4 spectra per pixel can be used. BR /!\ /!\ Much higher noise in HERA 2 than HERA 1 when using Vespa. This is being investigated by S. Navarro [RM 30.6.2005]BR /!\ When using HERA 1 and 2 configure only 1 Channel for continuum observations in OBS, never-the-less the continuum drifts of all channels are reduced (calibrated) by ODP [AS 11.10.2005]

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Bolometers

Mambo II is installed and ready for operation (AW 2004-12-01)

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Backends

/!\ 1 MHz Filterbank not yet integrated in new control system (RM 7.12.05)

  • 256 MHz shift in 100kHz FB header (AW 2004-12-01) (OLD CS) Software and/or hardware problem in the 1MHz FB - problem is currently investigated (AW 2004-12-01) (OLD CS)

    Spikes in VESPA at intersection of different units (AW 2004-12-01) BR

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Computer/Software

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Other Items

OK

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Updates/History

To see the changes between the actual and the last version, please see Show Changes in the Wiki Interface. If you want to see the Revision History of this page, please see Get Info in the Wiki Interface.

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Legend

(./) : OKBR /!\ : WarningBR {X} : ErrorBR

The wiki markup of these icons is:

{{{(./) : OK /!\ : Warning {X} : Error }}}

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TelescopeSystemStatus (last edited 2025-01-25 17:12:49 by msanchez)