Arecibo Report to EVN TOG:

Prepared by: Tapasi Ghosh
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1. Receiver/Antenna:

   Arecibo now has a 6 - 8 GHz (C-high) and a 8 - 10 GHz (X-band) receiver. The 
   respective SEFDs are 6 and 10 Jys respectively (they vary with ZA, see www.naic.edu
   ->scientific users -> Astronomy pages for more details)

   The X-band receiver was used in two VLBI runs in Sep03 and mar 04.

2. Hardware:

   MK5A : Arecibo is in the process of ordering a MK5A unit and 10 X 8 disk-packs
   (with 256 GB disks).  As Arecibo expects to join in many VLBA observations as
   well, VLBA-4 recorder will have to be kept alive as well until VLBA is equipped
   with disk-based systems.

3. Software: 

   Communication between the PCFS and  the telescope control software has been
   improved by a reworking the ANTCN programme. Ways to control the noise-diode
   via the FS has also been worked out. Currently, we are testing the IF/LO
   setup routines (so far it is done independent of the FS). Antenna position
   logging in also improved. 

   Amplitude calibration is still done using a stand-alone continuum system.
   Ways of measuring continuous SEFD via the PCFS  is being explored.

4. E-VLBI : Arecibo participated in the e-vlbi test runs and Internet-2 demo
   organised by Haystack. The data connectivity can be summerised as:

   Between Arecibo - Haystack:  UDP ~ 50 Mbps
                               TCP ~ 30 Mbps

   Between Arecibo - Indianapolis : (for the Internet-2 demo)  
                     Sustained rate was ~ 8 Mbps  

   However, at that time, our local node at University of PR, San Juan had
   a lot of technical troubles.

5. Personnel: Emmanuel Momjian has Joined the staff as a Post Doctoral Fellow.
   His area of speciality is VLBI. For is doctoral thesis, he worked
   with Jon Romney at Soccorro on many spectral-line VLBI projects.  He
   has already made a much improved VLBI web-page for Arecibo which addresses
   many FAQs related to including Arecibo in the users' VLBI runs.