TWTYTW

[Tom Droege <tdroege@veriomail.com>]

Possibly it would be good for my moral to review what has been accomplished 
during the last year.  It seems that I have found fixes for a lot of 
problems during this year.  The only really bad problems left are the 
declination drive and the icing problem.  Both can be solved by taking care 
in operation.  Possibly I missed some important event.  I would be happy to 
hear of additions.

January

January saw me working on the RA drive.  A topic that would recur during 
the whole year.  Some comfort in that ROTSE was reporting that their 
expensive lenses were 40% lower in the corners.  I had 9 cameras that I 
thought were working.

February

Problem of the month was leaking water in TOM.  I think I have finally 
learned to tie wrap all water joints and that prevents them from 
leaking.  There was a problem with the model airplane servos.  When I tried 
to buy more, they were discontinued and there was a big problem before I 
found more that fit.

March

I started working with Dave Garnett on the lens problems.  He brought up a 
lens design program.  Besides the previously found tube length problem, he 
found a #4 lens spacer problem.  Then we found that lens #5 was put in 
backwards.  With these changes the coma was much reduced.  Parts were 
ordered for the fixes.

I built a chiller out of an old de-humidifier and closed loop controlled it 
from the Mark IV.  Works fine, but now there is a CCD icing problem if run 
cold.  Our first tass paper appeared in PASP.

April

The camera heads were all revised to remove all the electrolytic caps and 
replace them with tantalums.  Probably not necessary, but we are doing them 
all so that all cameras will be alike.  The ice problems continue.  I tried 
a two stage TEC "getter" and then a one stage with some success.  But cold 
temperatures are still a problem.  We received the spacer rings for the 
Dave Garnett fix.

May

I gave up on the TEC "getter" and went to circulating dry air through the 
cameras.  This works better.  It is still important to seal the cameras 
well, so I worked on the "O" ring seal.  I found that some of the "O" ring 
was delivered as the wrong size, and replaced it.  I then redesigned the 
camera shell to make a better seal.  The new shells seal much better, and 
provide a little more space between the CCD and the filter/window to reduce 
the likelyhood of the window frosting.

June

I built a test set up so that it would be easier to check out boards for 
the systems.  The builders were here to raise the roof, fix the leaks, and 
add the Clam Shell Dome.  Many cameras had the new shells 
installed.  Worked on the problem of noise on a long cable and found a 
fix.  An RC on the clock line at the Memory Board keeps cross talk from 
clocking in extra bytes.  An electronics set was shipped to Chris Albertson 
so he could work on real time code.

July

July was spent getting ready to ship ARNE to Arizona.  A lot of production 
work on cameras.

August

Worked more on the RA drive.  There is a TN.  MIKE and GLENN were 
started.  Found that the GLENN side plates were drilled wrong.  The drawing 
was bad.  Worked on updating all the drawings and made a bunch of sets of 
the electronics which has mostly settled.  The 21 of August Bill Haynes and 
I took ARNE to Arizona.  We returned at the end of the with it working and 
taking images.

September

There was a problem seeing "Block Done" which was found to be a software 
initialization problem.  I worked on the camera vertical clocks where we 
added a time constant.  This probably did niether good nor harm, so we are 
adding it to all cameras so they will be identical.  The problem was that 
saturated pixels on the first lines read out were larger and those at the 
end of the frame.  What did work was changing the clock levels for optimum 
performance.  There were problems found with the focus trombone.  A 
modification was tried on MICHAEL.  We may or may not add it to all 
systems.  It probably does no good.  The solution may be to focus pointing 
straight up, where the bending of the trombone due to the weight of the 
cameras will be reduced.

October

We took lots of data on both TOM and MICHAEL

November

Enlisted a data reduction group.  About 100 CD roms of data were sent out 
to the various group members.  There are four analyzers working on the data 
by different methods.  Due to "breaking" MICHAEL's RA drive by not watching 
what I was doing, I redesigned the RA drive yet again.  The new design is 
much easier to set up and it is now possible to change the Chamois without 
taking the whole drive apart.

December

MICHAEL left for New York.  It may even be working there, but there are the 
usual problems.  We now have MIKE up on the production test stand, and 
GLENN up on the secondary stand.  It is time to order more parts.