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J.D. Bregman presented a detailed memo on the subject
P. Burgess noted that While the Bonn and Jive correlators could handle PCAL extraction, the Socorro VLBA correlator could not. Nevertheless if a PI proposed to send MkIV tapes to Socorro then phasecal extraction would be required. Several changes would have to be made:
P. Burgess inquired about the status of phasecal units at the various EVN Sites. Pablo Vicente had reported that no phase cal sytem was yet available at Yebes. At Noto the phase-cal was one of the new VLBA units and this was injected at the front end. A similar situation existed at Medicina although an antenna based unti was required for the 6GHZ receiver. Jodrell had built five of its own VLBA compatible units and one HSTK unit -- all were injected at the front end. At Westerbork the situation was somewhat different due to the nature of the phased array. The phase-cal was not injected at the front end. At Metsahovi the signal was injected at the IF as the level was too low to be injected at the front end. There were plans to change this in the future. At Effelsberg the phase-cal was injected at the front end for all receivers expcept at 43 GHz. P. Burgess stated that he had experienced problems with the level of the phase-cal signal when injected in the front-end of the Cambridge telescope at 22 GHz. T. Foley suggested that this might be a general problem at high frequencies. Perhaps the Haystack receiver coupling was different ? The phase-cal injection unit was based on the Rogers design. Torun had no phase-cal injection at the moment but it was hoped to adopt the VLBA design for the new 32m telescope. M.A. Garrett wondered how accurate the present system was. Perhaps the the CAL experiment could compare the alignment of the MkIII bands using phase-cal units with those made by observations of a strong calibrator.