[evlatests] Bad Tsys and Tcal values

[Barry Clark]

Rick Perley wrote:
>     A quick review of the reported system temperatures reveals a few 
> problems, mostly with the tabulated Tcal values.
> 
>     Q-Band:  Tsys is claimed to be 20K on the A and C IFs. (We wish!).  
> The problem is in the Tcal values, which are listed as 1K.  (Curiously, 
> the Tcal values for the BD side are find). 

What antenna?  What frequency?

> 
>     X-band:  Tsys is between 750 and 1000 K on ea05.  These look like 
> the truth, based on system noise. 
> 
>     U-band:  Tsys is claimed to be 10K for ea12.  The problem is with 
> Tcal, which is listed as 1.0 K. 

Obsolete Tcals replaced.

>                     Tsys for ea21 is between 50 and 60 -- looks like the 
> truth.  This is two times too high. 
> 
>     S-band:  Lots of problems here. 
>                   ea07 has a (probably real) Tsys of 100 to 250 K. 

Tcals are around 3, which is higher than most receivers

>                   ea15 has Tcals which are clearly 3 times higher than 
> they should be (except for IF 'A', which is 300 times too high).

The Tcals in the database are around 1.5 to 2 on both IFs, which look
pretty reasonable.  I don't know what is going on here.  Possible
cal switching problem?

>                   Antennas 16, 18, 21, 23, and 26 all have listed Tcal = 
> 1.0.  I guess these are newly installed receivers, and nobody has 
> updated the Tcals from their default numbers.

Don't quite know how this happened - I suspect they were previously
entered without the leading zero on the receiver serial number.  Now
fixed.
>                   ea22 has a claimed Tsys of 10K.  Here the problem is 
> that the Tcal values are listed as 0.75 K or so -- clearly a factor of 2 
> to 3 too low. 

Obsolete Tcals replace with newer values.

>                   ea08 has a Tsys of about 50 on the BD side. 
> 
>     L-band:  ea07 has a (real) Tsys of 75K. 
>                   ea18, on IFs A and C have Tcal values of 1.0  Seems 
> unlikely, given the derived Tsys = 20K.

Fixed.
>                  
> 
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