Performance and Reliability of the EVN;
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Session 1/2009 --------------


The session consisted of five frequency blocks (7mm, 1.3cm, 5cm, 6cm,
18cm). NMEs, ftp fringe tests, and calibration experiments
were performed in each block. The ftp data were processed in a 
semi-automated way. In the first 6cm ftp fringe tests experiments F09C1, fringes to all the
participated stations were successfully detected after fixing the ftp
transfering problem. The rest NME experiments ran smooothly. Nt and Mh reported 
MK5 problems in N09K2. 


There were 21 user experiments (1 at 7mm, 1 at 1.3cm, 9 at 5cm, 6 at
6cm, 4 at 18cm) in the session. There were nine 1024Mbps expriments
observed and two global VLBI experiments (GC031C & GB065A). 
The Yamaguchi 32m radio telescope participated in the EVN expriment EB039B 
for the first time. The Yebes 40m radio telescope started to perform the observatins 
at 5cm C band. 


Station and correlator feedback for individual stations:

Ef - Occasional RFI around 1600-1610 MHz and 1620 to 1628 MHz in 1-Gbps experiments.

Wb - RFI at 1610.49 USB+LSB and 1632.49 LSB in 1-Gbps experiments. In phased array mode except 
for the 5 cm expepriments. 

Nt - Recorder stuck from 06:00 to 08:30 UT in EB039B. Problems with
the BBC 6 for the whole experiments of EM062B, EM064F, and EM069D. Lost
half hour data in EW012B due to recording problems. Only the LCP polarisation was available 
at K band in session 1/2009. The RCP polarisation was not available until session 3/2009 
(See the lastest experiment F09K3 on 26/10/2009). 

On - Stowed the antenna a few times in EM062B and EM069F because of
high winds. Some scan_checks looked bad in EW012B and GC031C. RFIs were
reported in EM074, EP064C, EP064D, and N09L1.

Tr - Lost nearly 3 hour data in EW012B and half hour data in GC031C due
to recording failure of its Mk5A. The scan_check reported missing a few bits data
quite a few times in 1024 Mbps experiments. 

Hh - No observations again in the session due to the serious polar-mount
bearing problem.

Mc - Lost 100 min data in EW012B due to problems with one hard disc in
MK5 module OSOD-070.

Ur - Lost fringes in 1024 Mbps experiment: EP064A, EW012A, EP064B,
EW012B, and EP064D. Something was wrong with the MK5A IO board. The
recording bit-rate was over 1024 Mbps (~1450 Mbps), which was too fast
to be played back.

Sh - No known problems. 

Ys - Antenna stopped from 13:37 UT until 14:17 UT and from 14:50 UT until
15:00 UT in EM059D due to bad weather (wind and rain). The correlation 
amplitude had a fluctuation in N09K1. The culprit was a broken RG-58
cable which transports the 5 MHz reference to the 22 GHz receiver. The problem 
was found and corrected after the session.  

Mh - Problems recording at 1 Gbps in N09K2. Debug showed several messages
of Recording Throttled, which might be due to slow disks or over-rate recording.

Ro - Partipated in the experiment EP064C. Despite of data cables were directly connected to formatter, a few bits were lost during some scans.

Jb - The MkII telescope was used (Jb2). It had low sampler statitics in
the LCP channels for all Subands in C band experiments. Lost nearly 4 hour data
in EW012A.

Cm - The 16 MHz siganal was splited into two subbands in the experiments
with 16 MHz/subband.

Kn - Shared a MK5A with Cm. The 16 MHz siganal was also splited into
two subbands in the experiments of 16 MHz/subband.

Ar - Participated three experiments: GC031C, EP064B, & EP064D. No known problems. 

JIVE correlator operators reported that a disk pack containing Maxtor
disks suffered from a burned out IC on one of disks on 17 April
2009. The pack contained the data recorded at Onsala for EP064A. 
The event caused that its fisrt 4.5 hour data were lost.


Jun Yang for the Science Operations and Support Group (JIVE)