[mmaimcal]Re: [Almacal] memo 372 review reply - gurwell

[Larry D'Addario]

David Woody writes:
 > The system temperature is inversely proportional to the gain...

This is not true in a system where the gain is stable.  It is true in
a system that uses automatic level control, in which case the gain is
deliberately made unstable so as to track variations in the system
temperature.  I submit that this is a bad idea and should not be done
for ALMA.  My earlier remarks were based on the plan that ALMA will
not use ALC and that the gain will be made as stable and predictible
as possible for each observational setup.  Once it is understood that
gain is not coupled to system temperature, many of Dave's remarks do
not apply.

I hope soon to have time to describe more detail the plan that I have
in mind.  It is, admittedly, somewhat unconventional and it might have
significant flaws.

--Larry