hollis dinwiddieevla front-end cdr – feed circle & rx mounting april 24, 2006 1 evla front-end...
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Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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EVLA Front-End CDR
Feed Circle&
Receiver Mounting
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Flattened Feed Circle Layout
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Feed Circle Layout
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Vertex Cabin
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Vertex Cabin
• Each Feed is Tied into the Vertex Cabin Except the L-Band
• The Size and Receiver Weights Determine the Mounting Method for the Feeds and Receivers
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver Weights
Receiver Weight (lbs)L 173S TBDC 84X 49
Ka TBDK 76
Ku TBDQ 79
Chuck Kutz 205
Receiver Weights
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver Mounting
• Three Options for Receiver Mounting– Fully Fixed to Vertex Cabin– Fixed to Feed and Fixed to Vertex Cabin– Fixed only to Feed
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver MountingQ and Ka
• The Receiver is Directly Mounted to the Feed Tower.
• The Feed Holds No Structural Load
• The Receiver is Attached to Side of Vertex Cabin
• No Major Stress Concentrations
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver MountingK and Ku
• Feed Attached to the Feed Tower
• Receiver Attached to the Vertex Cabin Wall
• No Significant Stress in Feed
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver Mounting
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Receiver MountingL S C X
• The Feed is Secured at the Mounting Flange and the Throat Section
• The Receiver is Attached Solely to the Feed
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Mounting the L-Band
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Keeping the Feeds DryRadome
• Sealing The Feeds– All Feeds or Feed Towers are Sealed with
Radome to Keep Moisture Out
• Types of Radome – Esscolam 10 for L, S & C– Gore RA7906 for X, Ku & K
Hollis Dinwiddie EVLA Front-End CDR – Feed Circle & Rx MountingApril 24, 2006
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Keeping the Feeds DryDry Air Systems
• All Metal Feeds Sealed with O-Rings
• Desiccants • Dry Air Compressors
– Costly
• Positive Pressure Vertex Cabin– Experimental