[evlatests] More notes from April 11

[Pete Whiteis]

>
> Antenna 16 - The issue with the L302's occasionally getting into this 
> bad state is known and hopefully will be taken care of by the new 
> firmware.  It seems to happen when the MIB loses control of one of the 
> DDS chips - apparently the control loop device in Barry's case today. 
> For some reason the module does not go into standby when this 
> happens.  Usually, one MIB reboot fixes it but on rare occasions 
> additional MIB rebooting or a power cycle is required. This is the 
> same state I found one of Antenna 14's L302's in the other day.

The MIB can get into this state if the lock bit goes unstable (ie 
chatter).  This will cause the MIB to ping-pong between two valid 
states: maintaining lock, and then losing/finding lock.    I have seen 
this occur more than once during bench testing.      It takes a hard out 
of lock failure for it to transition back to standby.

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