[evlatests] Bad SPW / ea17 one subband no signal. / fixed now.

[Vivek Dhawan]

This is believed to be fixed as of 10 minutes ago.

for the record,  b107-t-6,7 had CRC errors on the
recirc chip X3Y3. a re-start fixed it. There are
still lower-level CRC errors in that same place,
but the correlation amplitude is good  - might go
bad over time.

Keep an eye out. Thanks, Vivek.


On Mon, July 3, 2023 14:35, Rick Perley via evlatests wrote:
| The situation is a bit less clear than I originally communicated:
|
| There is a difference between the polarizations:
|
| a) In LCP, SPW44 (in Ku-band) has no signal at all, while adjacent SPWs
| are fine.
|
| b) in RCP, SPW44 is also without signal, but adjacent SPWs (from 33 to
| 48) are highly attenuated.  Calibration recovers the signals in these
| other SPWs, without apparent loss of SNR.
|
| Rick
|
| On 7/1/23 15:30, Ken Sowinski wrote:
|> On Fri, 30 Jun 2023, Rick Perley wrote:
|>
|>> And I can confirm the problem (no correlations in SPW44, in Ku-band,
|>> for ea17 only, on all polarizations) is still with us.
|>
|> Just to be clear, does "all polarizations" means both pols of all If
|> pairs
|> or just both pairs of one IF pair?
|>
|> Ken
|>
|>
|>> On 6/30/23 12:03, Ken Sowinski wrote:
|>>> Â On Thu, 29 Jun 2023, Rick Perley via evlatests wrote:
|>>>
|>>>>  In reducing some data  taken over the past week or so, I note that a
|>>>> Â single spectral window, at Ku, K, and Ka bands, gives only noise
|>>>> -- no
|>>>> Â coherent signal visible in either polarization.
|>>>>
|>>>> Â The SPW is:Â  #44 in Ku band
|>>>>
|>>>>  and              #21 in both K and Ka bands.
|>>>>
|>>>>  The problem is not need in the low frequency bands (L though Ku). 
|>>>> Q-band
|>>>> Â was not observed.
|>>>>
|>>>> Â The problem was in every database taken since june 22.
|>>>
|>>> Â This didn't get as much attention as your complaint about ea27.
|>>>
|>>> Â If, as it appears, this affects all antennas then it sounds like
|>>>  a bad, or misconfigured, baselineboard.  Other possibilities are
|>>> Â the network switch or CBE, but a bad blb is much more likely.
|>>>
|>>> Â Ken
|>>
|>>
|
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