[evlatests] Antenna 11 drops at L-band -- gone

[Jim Jackson]

Rick,

Late last week, we swapped that L302-2 synthesizer (SN 17) with the 
L302-1 in the same antenna. Yesterday you mentioned a different but 
equally strange problem occurred with IF's A and C so we took that 
synthesizer out completely and replaced it with a spare.  Try to run 
antenna 11 through as many of your stress tests as you can over the 
next few days.  If no more problems show up, I'll give the thing to 
Matt along with the plots you gave me.  We've never been able to 
catch it doing anything wrong but if the problems don't return, we'll 
have to assume something is wrong with it.

Cheers,
Jim



At 08:43 AM 10/19/2007, Rick Perley wrote:
>     For a couple of weeks, antenna 11, on IFs B and D, at L-band, showed
>curious dropouts, lasting less than 1 second, on a ten-second interval.
>The dropouts were total, in that the source coherence went to complete
>noise for a single 0.418 second integration, with the two adjacent
>integrations having the coherence reduced by about one-half.
>
>     These dropouts now seem to be absent -- this statement based on
>three or four test observations made this week.  They were present last
>week.  I suppose that 'all's well that ends well' -- but it would be
>nice to know what was done to make these go away ...
>
>
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