[asac] DSB vs SSB option

[Min S. Yun]

Hi Stephane,

Just a couple more things to add to Roy's comment.  If we use
the DSB system and separate the sidebands in the correlator,
we need to be able to measure (and monitor?) the sideband
ratios, probably to the accuracy we demand for amplitude calibration.
This might not be difficult, but we need to work out the details.

A related problem is time requirement for Walsh function switching
cycle.  Perhaps someone has already worked this out, but I recall
the full cycle being of order 100 msec for OVRO.  With much
larger numbers of components we have, would this pose a problem
at all?

Your practical sugggestion of reducing the number of IF channels
is probably a good one.  It would be useful to get some quantitative
sense for what we are talking about here.  For example, could
you put some $$$ figures on having so many spares?  and how
often a receiver may be down?  or how many total per day?

Lastly, the bands and frequency ranges listed in Table 1 do not
seem consistent with what's in the project book.  You might
want to check that.


					-- Min

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Min S. Yun				e-mail: myun at astro.umass.edu
Assistant Professor			phone:  (413) 545-2215
Astronomy Department			FAX:    (413) 545-4223
University of Massachusetts             http://www.astro.umass.edu/~myun
Amherst, MA 01003