[evlatests] problems related to 3-bit samplers

[Eric Chavez]

The LO Group has replaced the L302-3 in Antenna 13.

Eric

Ken Sowinski wrote:
> ea26 now has a full complement of 3-bit samplers.  I have again
> run simple scripts to verify that all the samplers are behaving
> well in a general sense in preparatino for astronomical tests.
> 
> All the sample4rs in ea16, and ea23-D304 need attention and the
> DTS group is investigating.
> 
> The ea13-l302-3, which is used for ea13-A2C@ consistently goes
> to standby mode when commanded to 13073.1171.  It may do fso for
> other frequencies as well, but I have not looked for that.
> Commanding it elsewhere, and even rebooting the MIB, do not help.
> 
> Only one antenna, ea23  consistently failed to get the T304 attenuators
> and equalixzers set correctly.  This was found to be because the
> power feed to the downconverters was varying by a few dB on time scales
> of minutes at C bnad.  At X band the power was stable.  When the antenna
> is slewing the behavior is even more erratic: the power changes by a
> few dB in seconds instead of minutes.
> 
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