Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 1 Design, Manufacture, Transport and Integration on-site in Chile of ALMA AntennasENCODERS PM# June 2006

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 2 ENCODERS - Update Status - AZ encoder baseline: Reading heads possibly reduced to 8 instead of 10; decision at the final choice of bearing Alternative new interpolation boards excluded by the supplier; IK320V remains the actual and future solution. Production guaranteed. Waiting supplier schedule for tape qualification tests. - EL encoder baseline: 120mm internal diameter solution under analysis from the point of view of performances – 150mm study already implemented. IP protection studied by EIE waiting proposal from supplier; this confirmed its availability to supply the complete set protected as per prototype. Mounting and alignment w.r.t. the shaft issues under analyses. - Alternative Solutions: Still under discussion; difficulties in having information from US companies (TAA/TDL required).

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 3 Encoders Block Diagram

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Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 5 Design, Manufacture, Transport and Integration on-site in Chile of ALMA AntennasACU PM# June 2006

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 6 Preliminary Crate Layout - Front

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 7 Preliminary PCU Layout