- 07 Jun 2007
1.2 Mechanical Design and Specs – The observatory's experience with ALMA, as well as the experience of other institutions who have built focal plane arrays, has shown that mechanical assembly is an often overlooked or underestimated issue with multi-feed systems. The pixel cartridges must be designed to allow easy access to flange screws, connectors, and interfaces, even after assembly into a close-packed array. A careful mechanical design will thus be developed in the early stages of the project, specifying the outer dimensions of the cartridge, the location of connectors, access paths to screw heads, etc.
1.2.1 A complete dewar with a waveguide window for cooling the an orthomode transducer, a polarizer, noise calibrator, and HEMT amplifier with a mounting flange for the feed. A plate will be provided for mounting in the GBT turret with provisions for moving the pixel to different locations in the focal plane.
1.2.2 A complete dewar with seven waveguide windows for cooling the orthomode transducers, the polarizers, noise calibrator, and the HEMT amplifiers with a mounting flange for all seven feeds.
1.2.3 A frame for mounting the downconverter, LO module, monitor electronics, and cable wrap for a rotator.
1.2.4 A parallactic rotator equipped with electronic control and monitors for use with the GBT M&C system.