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Re: how to find Inmarsat umbrella dishes



The umbrella type of antenna was only used by two manufacturers, MTI / TCS
and Magnavox. The MTI/TCS antenna was the mesh version like Howard's, The
Magnavox version was more of a metalized cloth. They were primarily used on
Inmarsat standard A terminals. Inmarsat has announced that standard A
service will be discontinued around 2008 so maybe more of these antennas may
start to show up. Most all the current Inmarsat terminals employ arrays of
patches. I have seen a few damaged panels and the internal constructioin
consists of several foil patches fed for RHCP glued onto a sheet of
styrofoam.  The styrofoam is then sanwiched between thin fiberglass like
material and sealed for protection. Of course the simple construction masks
the complexity of the proper phasing and feed point placement. The narrow
bandwidth of the patch elements probably preclude any possibility of
modifying a surplus Inmarsat antenna for 1269 operation.

Howie AB2S

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