[evlatests] 'Missing' panels on ea21

[Dave Parker]

I antenna 21 the antenna that had a panel blow off in high winds a year 
or two ago, and was holography done on it after it was reinstalled?

Dave

On 5/19/2021 3:01 PM, rperley via evlatests wrote:
> I'm reviewing all the surface holography taken over the past three 
> years.  The good news is that there is ample evidence that the panels 
> don't change over this period of time, so that once we've made our 
> 'best' adjustments, no more adjustments will be needed for a long time.
> 
> The 'bad' news is that something is quite amiss with ea21.  We're 
> getting no signals from two panels - this is seen in both the Jan 2019 
> and May 2020 data.
> 
> Of course, these panels cannot be 'gone' (one hopes that somebody would 
> have noticed this, were that the case ...).  What has happened is that 
> the two panels are tilted so much that we don't get a coherent signal 
> over the resolution of the measurements.
> 
> The two panels are in the outermost right, and, as seen from the front, 
> looking into the dish, are the top two panels on the right side of the 
> quad leg.
> 
> It would be useful for somebody to look at these -- the effect will be 
> very slight, so don't expect an obvious tilt.  It takes only a couple of 
> millimeters of slope, over the extent of the panel, to make it 'disappear'.
> 
> Rick
> 
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