[evlatests] Antenna 23 is tardy

[Ken Sowinski]

On Tue, 6 Jul 2010, Doug Whiton wrote:

> Please be more specific, if you can.  Are you complaining about AZ or EL?
> How much of a difference from other antennas on the same arm are we
> talking about?   Specs are 20 deg/min for EL and 40 deg/min AZ.  We allow
> a + or - 5% window.  That's 1 deg/min in EL and 2 deg/min in AZ.
>
> We looked at both AZ and EL this morning.  El slewed at 22 deg/min down
> and 21 deg/min up.  AZ slewed at 38 deg/min both CW and CCW.  We can
> easily
> set the speed with digital tachs.  They will be installed when the antenna
> comes in to finish the overhaul.  Until then, I am inclined to do nothing,
> unless you have some more information.

Historically ea23 has been slowest of the antennas during
azimuth slews.  For a full 360 degree wrap change it would
take guite a few tens of seconds to get on source.  I can't
remember the exact amount of the lag, but it seemed to be 
more than the 9*0.05 minutes exepected from the slew rate you
measured.  Next time there I happen to see a long slew I
will try to characterize it more carefully.

There amy be other opinions, but waiting for the digital
tach seems fine to me.