Biennial Report 2003-2004 - Merlin

22
Most of the engineering work in 2003 and 2004 was
directed towards e-MERLIN developments, which are
reported elsewhere. In addition to this, two major
projects were undertaken (by our own staff) and one
telescope was repainted (by contractors) during the
2003 and 2004 summer maintenance periods,
together with a number of minor works such as the
refurbishment of equipment cabins.
D
R EPL EPL EPLA EPL CEMENT CEMENT CEMENT OF OF DDEFF
D EFF EFFORD EFF ORD
C
Biennial Report 2003-2004
ORD & & M MMK
M 2
S
T ELESCOPE ELESCOPE CCONTROL
C ONTROL SSYSTEMS
S YSTEMS
Following the successful replacement of the obsolete
control systems on the three E-Systems telescopes
between 1999 and 2002, similar upgrades were
implemented on the Defford and Mk2 telescopes in
2003 and 2004 respectively. Both of these telescopes
date from the 1960s, and the amount of work
involved in replacing the control systems was
considerably greater than might be imagined, because
it proved necessary to replace almost every cable,
switch, etc. in order to meet current standards and
ensure reliability (Figure 29).
Figure 29: Some of the life expired material removed from the Defford telescope.
P
C O O R R R R O O S S I I O O O N N P R R O O T T E E C C T T I I O O N
N
The Pickmere telescope was painted by contractors
in 2004 using one of the modern paint systems that
have proved effective in doubling the recoating interval
(from 5 to 10 years) at little extra cost. Despite these
improved paint systems, inadequate funding is
threatening the structural integrity of the telescopes
by restricting the frequency of painting to a level
below that regarded as optimum.
MERLIN/VLBI National Facility
ENGINEERING
ENGINEERING
Figure 30: A new e-MERLIN C-band feed fitted on the
Mk2 and Defford antennas.
Figure 31: An L-band feedhorn being installed on a
MERLIN E-Systems telescope.