[mmaimcal] Change to Production Antenna Focus Translation Tilt Capability

[Alwyn Wootten]

25.  	Change to Production Antenna Focus Translation Tilt Capability
	Reply
CRE Number :
ALMA-34.00.00.00-034-A-CRE

The CRE to enable hexapod tile should be approved, for the increase in
ALMA effective collecting area it provides, as well as for the flexibility
it provides.  ALMA's sensitivity is already hobbled by the fact that we
have contracts to procure only 50 of the 64 antennas in the bilateral
scope.

The Melco and Vertex antennas both allow some degree of subreflector tilt,
according to posted information.

The value of this CRE is approximately half a fully equipped antenna worth
of collecting area per antenna contract.  Thus it is worth somewhere
around $4M if we were to try to obtain this much collecting area by
building another antenna.  The cost of this CRE is about a tenth of this.
Clearly this is worth the call on contingency.

GO!

Al