[mmaimcal] Q-band on ALMA

[Al Wootten]

Steven T. Myers writes:
 > 
 > Indeed, I have been assuming that the 30-45 GHz would be in a second 
 > dewar - that is the main argument for dropping it, just the pure
 > cost of the second dewar and pickoff optics.  It would seem to
 > make sense to have more than one of the lower bands in the second
 > dewar if there was one at all, and that 67-90 would be a good complement.
 > Maybe that is the case we should put forward in the "low frequency
 > band" defense.  
John Payne is supposed to be developing an actual cost for his 30-45 GHz
plan within a week timescale.  It is interesting that we never went through
this exercise in such detail when 900 GHz was added, or when the size was 
changed from 8 to 10 to 12m.
 > 
 > Al - has your white paper on the frequency band selection from 98
 > somehow been superseded?  That seemed to be a nice clear memo...
No.  It was a conservative approach; John Webber has a more daring plan
which would cover all of the bands somewhat more effectively, but no one
is sure it can be implemented.
 > 
 > It seems there are a number of "decisions" that are being made to being
 > threatened without real consultation eg. subarrays, correlator (which
 > seems to be under control now), dewars, Ka/Q/W/D (or even the basic
 > focal plane design).  Anything else we need to stay on top of?
Everything!  Larry's system design, currently under discussion in Darrel's
Weds meetings for one, but the whole project is moving along at pretty
good speed despite the Euro-changes.

Clear skies,
Al