Minutes of NCCS Progress Meeting # 43

Jonathan Quick

22 April 1999

This was the forty-third progress meeting on the NCCS after the initial meeting with all concerned staff on the 17th January 1996.

Present were :

• J.Quick (convener+scribe), M.Ainley, M.Gaylard, K.Jones, J.Kriel, F.Nel, G.Nicolson, P.Stocker, A.v Wyk.

The minutes of the previous meeting were accepted.

Following the presentation of a proposed tasklist for Phase 2, the following points were discussed :

1.

Phase 1 Hardware (Outstanding) -

• G.Nicolson reported that although certain of the outstanding noise diodes have been installed, the remainder would only be installed as and when the corresponding feed systems are upgraded. He pointed out that the new NoiseCom diodes require a parallel 10k termination in order to function correctly with the NCCS noise diode controllers.
• G.Nicolson suggested that as an upgrade of the 3.5cm Dicke switch would involve installation of new hardware, it should be deferred until the 3.5cm feed system is upgraded.
• J.Quick re-iterated that final installation of the IF distribution system will have to wait until the new Electric Drive control panel / servo system has been completed.

2.

Phase 2 Hardware -

• G.Nicolson chaired a discussion on the new Electric Drive system.
  • The following issues are outstanding:

    (a)

    Replacement of the Hour Angle servo amplifier/integrator

    (b)

    Finalisation of all interlocks and associated logic

    (c)

    Replacement of the Limit Switch cabling

    (d)

    Elimination of all obsolete panels/cabling.

  • Once the first two items have been handled, the prototyping of the new Drive Control/Status panel should be complete, hopefully by the end of April.
  • It was suggested that a 1 month shakedown period should follow, during which the last two items can be addressed and the physical design and board layouts finalised.
  • The final layouts should be ready to be sent for production by the end of May with integration and testing during June.
  • Implementation of the new panel should follow early in July.
• J.Quick reported that the AT Multibeam Correlator and companion AT Distributed Clock have been fully installed. Only the associated control network cabling still needed finalisation.
• J.Quick requested that testing and qualification of the Counter boards for the Linux STEER cage be prioritised, given that Continuum Radiometry is a fundamental requirement for Phase 2. It was agreed that this would be done during the shakedown period of the Electric Drive.
• J.Quick added that qualification of the V/F prototypes could only be done once suitable counter boards were available and the necessary device server software has been completed. Construction of the required set of V/Fs would only commence once we were satisfied with their performance.
• G.Nicolson suggested that the current 18cm and 13cm radiometers be converted to a LCP/RCP pair of Noise Adding/Total Power radiometers, configurable under NCCS control. The current 6cm and 3.5cm radiometers would likewise be configured as a LCP/RCP pair of Dicke Switching radiometers.
• G.Nicolson added that a six way dual IF selector analagous to the Mark IV VLBI IF selector should be constructed to switch the requisite IF inputs to these radiometers.
• J.Quick suggested that the Pulsar Timer should be converted to accept the standard 160 MHz tuneable IF input, simultaneous with the changeover to NCCS control.

3.

Other -

• Detailed discussion of the software tasklist was held-over for a separate meeting with interested parties.
• G.Nicolson requested that a timeline reflecting the inter-connections of the above tasks be produced and the critical path identified.
• M.Gaylard reminded the meeting of the imminent demise of the HP1000s.