REPORT TO THE EVN CONSORTIUM FROM THE MPIFR, BONN


                   Dwingeloo, 29 November, 2006


EFFELSBERG

The new subreflector for secondary focus operation was successfully
mounted on the Effelsberg telescope on 5 October, with the help of two
70m cranes. The rms of the panels is 60 microns.  It has a hexapod
mount, which allows a wide range of positioning and pointing to
achieve precise focus. The panels are moveable with 100 actuators,
which will allow compensation of errors in the primary 100m dish, and
also corrections for departure from true homologous deformation with
elevation.  Work is currently centred on controlling the subreflector
positioning.

First tests indicate a much improved (15%) gain at 2cm and it is hoped
that greater improvements will result at 1.3 cm, and 9, 7 and 3 mm.

Only secondary focus receivers are available at present.  Work has
begun on installing prime focus receivers.  Operation at prime focus
is expected to start in January.


BONN

Dr. Dharam Vir Lal has joined the VLBI group as a post-doctoral fellow
to work with Andrew Lobanov on SKA array simulations, as part of the
SKADS project.

Dr. Yuri Kovalev has joined as a von Humboldt Foundation post-doctoral
research fellow.

Kosmas Lazaridis is a new PhD student, supervised by Alex Jessner.

Elena Cenacchi is a new student appointed under the ESTRELLA program,
and is supervised by Alex Kraus.



Richard Porcas

23 November 2006


addendum from Antonios Polatidis

 OPERATIONS

- All but one experiments of the June session and all experiments of
  the November session were recorded on diskpacks. In June 2006, we
  experienced some problems when switching diskpacks due to defective
  power supplies of the Mark5 system, which were corrected before
  Session3/2006.

- In Nov 2006, Mk5 problems have been experienced due to use of a
  ServerWorks chipset with Linux 2.6.8 kernel.

- Since November 2006, Effelsberg is a disk only station. The VLBA tape
  machine has been retired. The VLBA terminal is capable of 512Mbit/s and
  will initially share a mk5a unit with the mk4 terminal. During 2007 the 
  mk4 terminal will be converted to VSI and receive its own mk5b recorder,
  the VLBA terminal will remain as  mk5a.