SUMMARY / EVLA Bins and Modules Internal Design Review This report is a summary of the findings of the EVLA Bins and Modules PDR Review Panel based on a top level presentation of the design plans conducted on June 17, 2002, at Socorro. The purpose of the review was to answer 3 principal questions: 1. Are the top level performance requirements complete and adequate? 2. Have the correct design solutions been selected for study and development during the EVLA design phase: Are there important alternate solutions that are not being studied? 3. Has an adequate procurement plan been identified for the subsystem? Members of the Review Panel attending were the following: Peter Napier, Project Manager Barry Clark, Software Systems Engineer Jim Jackson, Hardware Systems Engineer Terry Cotter, LO/IF Task Leader Paul Lilie, Receivers/Feeds Task Leader Pat Madigan, Machine Shop Leader Rob Long, ALMA LO/IF/FO Task Leader Mike Revnell, EVLA Sampler Engineer Wayne Koski, EVLA MIB Engineer RFI A significant part of the bins and modules design must address RFI issues. Although detrimental levels have been identified, the role of vertex shielding must be understood in order to more specifically identify shielding requirements for the vertex room modules. The Interference Protection office is conducting tests to characterize the shielding required. RFI considerations dominate selection of connectors and front panel design. Blind mate OSPs, Dsub for M&C, and power connectors will be selected based largely on RFI suppression characteristics. The specifications for the EMI design are dictated by the detrimental levels as shown in the Overall RFI Hardware Plan (draft) and by measured emissions from equipment going into the racks. The EMI design must suppress emissions below the detrimental levels. A plan to improve B-rack shielding needs to be accomplished; LO/IF and Interference Protection will be performing this study. wbs Racks for the MCB are included in the Fiber Optics budget. MCB, Samplers, LO/IF and FE/cryo module costs are covered, but existing the U/X band frequency converter housing may not be. Certain utility modules may not be covered. A module checklist needs to be developed to show requirements in the following areas, to insure costs are covered in the wbs, and to provide for a design review. The design review will consider maintainability, uniformity, reliability, and RFI. Differing RFI requirements drive the differences between module and rack designs and drive the need for custom designs. Two basic custom module designs are planned, named "LO/IF" and "Sampler." COTS designs were considered not viable. Servo (Broilo) Will use existing and COTS equipment for prototype design. Front End receivers (Lilie, Mertely, Hayward) Will use COTS card cage. Front End digital control (Dooley) Will use LO/IF design. LO/IF (Jenkins) Custom design like the existing one to provide RFI shielding and dissipation of heat via conduction and heat sink. DTS/samplers (Durand) Custom design for high heat dissipation and high RFI emissions. Rack will be air-cooled with RFI filter on air ducts. No blind mating connectors. Routers (Durand/Revnell) Commercial equipment will be installed in a second rack designed like the sampler rack but built narrower to accomodate the normal 19" COTS equipment that will go in it. We investigated putting the routers in the same rack with the samplers but the commercial equipment uses side-to-side airflow and would prevent proper cooling of the sampler/DTS modules if mounted in the same rack. U/X converter (Harden) Will use sampler design. Drawings Drawings not shown on Web site. Some of the drawings are shown on file host but are not ready for the Web site. All designers are encouraged to place their drawings on file host for security, even if the drawings are in a state of development. The drawings will be accessible through the Web drawing switchboard only after they are released to Drafting. Vertex room The vertex room is being designed by the Antenna Group. The method of access to the upper level of the vertex room has not yet been decided. The Antenna Group plans to replace the vertex HVAC system. The new system will provide proportional control like the current one to maintain tight temperature control. Energy efficiency may be improved by using outside air drawn through an RFI filter. The Antenna Group wbs provides $5k/antenna for HVAC upgrade. The vertex room layout will be decided by the Antenna Group after close coordination with the Hardware Systems Engineer. Transition issues: The current plan is to remove the A-rack from the test antenna. Doing so requires replacement U and C band receivers with controllers, but not necessarily before the antenna is put back in the array. The B-rack transition plans will be developed by the LO/IF Group. The basic requirement is to keep the current rack but provide improved RFI shielding, to move it to a new location, and to move it to the floor. Replacement receiver controller card cages are currently being designed with the plan of having a transition module while switching from F14s to MIBs. WVR The K-band receiver will be able to support the weight of the WVR. Production WVRs will be lighter and Jim Ruff's new throat design will add rigidity to the feed. Module Design Guide pins are expected to be adequate to avoid alignment problems being experienced with the current guide blocks. The RFI gasketing spec of 80 - 130 dB at 1 GHz appears to be adequate based on tests by Interference Protection. Mechanical protection will be provided for the honeycomb RFI filter. LO/IF will determine if the YIG oscillators have adequate shielding from magnetic fields. Schedule The module design will be prototyped and tested before a final design decision is announced. For the panel, Clint