The Struggle

[Thomas Droege <tdroege2@earthlink.net>]

I have been really struggling the last several weeks.  I have been trying
to get the test setup working so that I could get all the cameras working
identically and everything adjusted in order to start the real data runs.

Sigh!  Retirement was supposed to be fun.  But it seems that if you try to
do something, sooner or later there is some hard work involved.  That is
what I have been doing the last several weeks.  Hard work!  I might as well
be in stir pounding big rocks into gravel.  

OK, today there was the first hint of progress.  The problem is that when
you start with a pile of sick boards, there is no clue as to what is good. 
I have been signal tracing step by step with my trusty oscilloscope, but
the real problem seems to have been at a very low level where it is very
hard to see what is going on.  

The test set up is not like the real camera system.  When I designed the
camera I worried a lot about how signals got from place to place.  I did
not worry as much for the test set up which was built for convenience in
testing the boards.  I should have worried more it seems as I have probably
been fighting a low level oscillation that mucked up the data just enough
that I could see that something was wrong.

I finally brought the TOM1 boards down and put them on the test setup.  The
same problem persisted, but now I could fight it with a known good board
set.  Sigh!  It finally started working when I did things that tend to kill
oscillations.  Now over the next week I will rebuild the set up so that it
has a better design from the view of noise and oscillations.  We shall see.

The general goal is to spend the next few months building up a set of
spares and extra cameras.  I will now be able to sort of test the optics in
the test box.  At least I should be able to see a lens that is different
from the others.  So I will test everything, put a good set in TOM1, TOM2,
and TOM3, and start a real data run.

This work should also allow me to support the systems in the field better. 
We shall see.

Tom Droege


Tom  Droege Jennifer Malpass
tdroege2@earthlink.net