Report for VLBI at Westerbork Nov 2007
======================================

Changes since may 2007:

Sessions:
       2007-2 had several problems with the local control systems (a
RAID card on a server, and the old tied array hardware) these caused
some observing time to be lost.
       2007-3 went very smoothly with only minor problems.

Tied array: 
       The new (fully digital) tied array hardware (TADUmax) was installed,
and initial local tests were made using the Mark5B recorder on loan from
JIVE.  At the start of November we were still commissioning the interface
between the new tied array, the recorder and the local observing software.

Single Dish:
       A modification to the mixing and filtering for single dish was made to 
allow the full (160MHz per IF cable) bandwidth from the receivers to be
made available at the VLBI rack. This had the additional benefit that the 
mixing scheme was simpler and that it was more straightforward to allow
the high band patching by changing 2 filters.
       The idea behind this was to allow more compatibility with geodesy 
receiver systems by modifying the Westerbork test 3.6cm receiver have another
mixing setup to provide 2 parts of the band with a fixed sky frequency offset 
and transport these over the 2 IF cables. This has not yet been implemented, 
although a wideband circular polarizer has installed on that receiver.

Field system:
       No major changes

Acquisition rack:
       No major changes

Other: 
        After the problems in session 2007-2 effort was directed to
streamlining the observing VLBI and local synthesise observing procedures
and improving operator documentation (in Wiki format). This has also been
dictated by the fact that the Observatory took over LOFAR operations in
October without (yet) any increase in manpower.