[evlatests] ea17 & ea25 phase jump problem

[Jerry Langevin]

Claire,

ea17 L302-1 installed jumper
ea17 L302-2 installed jumper
ea25 l302-1 removed a jumper
ea25 l302-2 installed a jumper
This should take care of the phase jumps on 8 bit IF's

Jerry
LOIF/VLA



Claire Chandler wrote:
> Correction, so far we have seen this at L, Ku, and Ka-bands.
> 
> Claire
> 
> On Fri, 1 Feb 2013, Claire Chandler wrote:
> 
>> In the pipeline-calibrated datasets from this last week we have been seeing 
>> phase jumps at scan boundaries on ea17 and ea25 in observations that use the 
>> 8-bit system at L, Ku, and K-bands (phase plot attached; other bands may also 
>> be affected, but we are limited to what our observers are using in this 
>> diagnosis).  3-bit observations do not seem to be affected.  The phase jumps 
>> occur on all 8-bit IFs (A0C0 and B0D0), and show multiple (but stable, within 
>> scans) phase states.  We are having to advise our users to flag these two 
>> antennas completely.  Is this a cable length problem?
>>
>> Claire
>>
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