Westerbork VLBI report for TOG 19 April 2009 
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Personnel:
        
        Since October 2008, Nicolas Pradel (pradel@astron.nl) is the
        VLBI friend for WSRT.


Regular Session Participation:

        Westerbork participated fully in the X,M,C and L-band
        experiments of session 2008-3 and 2009-1.  Observing was
        successful, with almost no time lost in both sessions.  A
        problem with duplicate diskpack labels in Session 2009-1 was
        solved thanks to JIVE staff.

e-VLBI:

	Westerbork performed well during e-VLBI observations and tests
        (see http://www.expres-eu.org/evlbi.html). e-VLBI is now done
        using TADUmax and Mark5B

Tied Array: 

        The new (fully digital) tied array hardware (TADUmax) has been
	used for both session 2008-3 and 2009-1) Apart from a few
	specific issues (3.6cm tuning problems and a few formatter
	resyncs), it performed well.
       
Single Dish:

       The 5cm session of 2009-1 was done using the Mark4 and the
       Mark5A.  
       It was recently decided to use in the future the TADUmax and
       Mark5B also for single dish.

Field System:

       After the upgrade to to FS-Linux 7 and FS9.10.3, we had a FS
       time jump (2 times). A computer reboot solved the problem. See
       Ed Himwich's email on this subject.

Mark4 Acquisition Rack:

       No major changes. With the move of single dish observations to
       the TADUnax/Mark5B combination, it is foreseen that the Mark4
       will not be used any further.

Mark5 Recorders

      For session 2008-3 the old Redhat operating system was
      used. Recording was fine, but the autoftp procedure did not
      work. Extracting the appropriate scan data had to be done
      manually using byte-offsets (the same problem affected the
      Mark5A).
      
      The operating system was upgraded to Debian Etch (2.6.18.dfsg
      1-23) just before session 2009-1. The DMINO software was also
      upgraded to the newest version (2007y222d04h). Now the autoFTP
      procedure works without problems.

      The Mark5A which was only used for single dish mode worked fine.
      With the changes in the single dish observing, the Mark5A and an
      upgrade kit will be returned to JIVE from where it was on loan.

      WSRT will only have a single Mark5B system in the future.


Other: 

      All e-VLBI observations were made by remote control (from the
      Dwingeloo control room, home and the JIVE control room). The
      normal sessions were done by the operators at the WSRT site.

      In the near future all the VLBI operations will also be
      controlled from the Dwingeloo control room so effort is spent
      into making the remainder systems ready for remote control and
      plans are drawn to stream data to a Mark5B system located at the
      Dwingeloo control room.