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hardware:dbbc.currentissues

DBBC-HB at Yarragadee

  • Currently working OK. Occasional jumps in delay now seem to be a Mark5 issue (Jan 2012)
  • Main problem is low gain through DBBC Conditioning Module B in the upper X-band channel. At the moment we have an alternative firmware config which puts the upper X-band channels through CoMo A and lower through CoMo B. This is giving good results but the underlying problem still needs addressing.

DBBC-AUSCOPE2 in Katherine

  • dbbcifc always reads slightly low (52000-54000). We have switched CoMos without make any difference and amplifying the signal does not affect this.
  • Otherwise OK.

DBBC-AUSCOPE3 in Hobart

  • Currently in use for IVS observations and seems to be performing reliably although it is necessary to monitor the delay through the system as it can sometimes drift. The channel drop-outs and unusual bandpass shapes described below seem not to occur often. It looks like performance has improved since the front perspex cover was removed from the front of the unit. Perhaps ventilation has been a problem.
  • dbbcifd power always reads slightly low (52000-54000). We have switched CoMos without make any difference and amplifying the signal does not affect this.
  • This problem now occurs VERY rarely: Performance seems ok except that channels 3 and 4 intermittently drop out, with recorded data consisting solely of -1 (1-bit recording). There are no indications of this error state in the LEDs of the front panel. NOTE: as of 4 Nov 2010, not always channels 3 and 4. This time channels 1, 9, 11 and 12 dropped out:
    Autocorrelation plot.
    On another occasion channels 1, 2, 9 and 11 dropped out while channels 12 and 14 looked strange:

/home/www/auscope/opswiki/data/pages/hardware/dbbc.currentissues.txt · Last modified: 2012/01/10 21:47 by Jim Lovell