[evlatests] December Engineering/Tests Meeting

[Bryan Butler]

found a bug.  conclusion still the same.


       time period          SBs   hours  band switches  no band switch
------------------------  -----  -----  -------------  --------------
2016 nov 1 - 2016 nov 30    266    560       1290           12605
2015 dec 1 - 2016 dec 1    3214   5912      13902          170043
2012 dec 1 - 2016 dec 1   12126  24250      58227          684849



Bryan Butler wrote on 12/19/16 12:00 :
>
> some data on how many band switches we make.
>
> numbers are approximate because i'm not including test time (though we
> don't often switch bands during testing), and i don't catch quite
> *everything* that is science observing, but they are first order
> probably about right.  i did three scales of length of time as a sanity
> check that the values scale about right, which they do.
>
> over the month of november 2016 we had ~570 hours of science observing
> time in 274 SBs on the VLA.  during that time there were ~1942 true band
> switches, and ~12400 scans that didn't switch bands.  i give "~" values
> because i'm assuming that the first scan of an SB always switches bands,
> which isn't necessarily true, but i figured was the most conservative,
> and it will catch some of the missed test time band switches.
>
> over the year from december 1 2015 to december 1 2016, we had ~5912
> hours of science observing time in 3214 SBs on the VLA.  during that
> time there were ~20800 true band switches, and ~163000 scans that didn't
> switch bands.
>
> over the four years from december 1 2012 to december 1 2016, we had
> ~24250 hours of science observing time in 12126 SBs on the VLA.  during
> that time there were ~86300 true band switches, and ~656780 scans that
> didn't switch bands.
>
> steve tells me that hichem says that if there is no change in bands at a
> scan boundary, the switch is not told to do anything.  if that is really
> the case, then these switches have not gone through anything even close
> to 1000000 cycles.  if, however, for some reason they actually are
> cycling at such a scan boundary, then we're getting to about 3/4 lifetime.
>
>     -bryan
>
>
> Rick Perley wrote on 12/14/16 15:24 :
>>     All:
>>
>>     We have three items (so far) for discussion.  There's time for more
>> -- let me know if you have something to show/tell/discuss.
>>
>>     1) Steve:         RF Switches.
>>
>
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