A late-season spring cold front had passed during the day on Thursday, and
the skies were perfectly clear by nightfall. I had about two day's worth
of work that I needed to accomplish on Friday, so I reluctantly decided
to stay home so I could get to bed early and take my chances that the
weather would hold for yet another night. I rationalized by saying that
the upper atmosphere is more stable the second day after a frontal passage
anyhow.
Friday morning broke to a totally cloudless sky, and although the wind was
still a bit brisk, it slowly subsided during the day. By late afternoon,
only a breath of air remained, not more than 2 knots in velocity. I
arrived at my favorite spot in the Everglades a couple of minutes after
sunset, and I was set up for imaging just as the final twinges of twilight
faded into blackness. It was readily apparent that tonight I was going to
be treated to the most perfect weather for viewing the heavens that I have
ever experienced in South Florida. The temperature was in the mid 70s, the
wind was light and steady, there was no haze and there were no clouds, the
upper atmosphere was rock solid, the humidity was low, there was no dew,
and there were no mosquitoes at all. Apparently a week of steady rain has
drowned out all the mosquitoes and all the puddles with their larvae have
overflowed into the streams and out to sea.
So much for the good news, now on to the bad news. The first image from
my camera came in completely black. Not even the normal readout noise of
a dark-field image was present. I checked all the cables and connections,
but they were all OK. I exited from and then re-started the imaging
program, but the results were the same. I ran a signal connection utility,
but it reported no problems. I powered down and re-started both the
computer and the camera several times, all to no avail. Ultimately,
removed the nosepiece from the camera and aimed a flashlight directly
onto the CCD chip. After several such experiments, I concluded that
something very basic in the camera had failed, possibly the CCD chip or
the analog to digital converter. Any problems further downstream would
have produced a software detectable error condition. For a little while,
I tried imaging with the STV autoguider, but the resulting images were
simply not up to the standards of the MX7c that I have come to love so
much. With a nearly undescribable sadness, I powered down all my
electronics and packed everything back into their carrying cases.
Since the night was still young, and since the weather was so impeccably
perfect, I installed eyepieces and counterbalances and set up my telescope
for visual work. The viewing was wonderful, but I must give a word
of warning to anyone who is considering switching to imaging: Once you
have climbed the learning curve and have taken several beautiful full
color images of an assortment of objects, you will never again be
happy or satisfied with looking at things through an eyepiece. I have an
impressive array of eyepieces, but the problem is this: no color, no
clarity, and no detail. After two hours of dutifully peering up at the
sky, my sadness over all the lost images had brought me to the point of
tears, so I packed up my scope and headed for home.
I arrived back at home at 3:30 AM, and even though I was a bit tired, I
was completely unable to sleep with the thoughts of my broken MX7 haunting
me. There was only one solution to the problem, so I got out of bed and
tore the camera apart. Once it was completely dismantled, I found that
the CCD chip was not seated down into its socket. It turns out that the
designer of this fine camera neglected to include any mechanism to retain
the all-important CCD into position. To get the chip high enough off the
PCB so it can sit atop the TEC unit, the CCD DIP is inserted into a socket
that has the center hollowed out of it. That socket is inserted into
yet another socket soldered into the board. The only retaining system is
the insertion force of the sockets. There is absolutely nothing at all
to keep the chip parallel to the PCB and thus perpendicular to the
incoming light. The pins on the chip do not fit all the way down into
the socket. I guess you are just suppose to wiggle it into some
approximate alignment, without a tool or any way of checking it. Silicone
grease is suppose to do the rest. They even use silicone grease to seal
the chip chamber so no moisture gets in. There is no desiccant, nor is
there any provision to install one.
Right now I am a bit bummed out. Not only did I loose one of the best
evenings ever, but now I have a great feeling of insecurity concerning
my MX7 camera. I do not know what could have caused the chip to come
out of its socket, irregardless of how little the retention force is.
I always exercise great caution when handling it, and it has never been
dropped. Additionally, I have no idea how I am going to realign the chip
so that it is square enough to use again.
It is now 6:30 AM, and I am finally going to go to bed. I think that
this has been the most disappointing evening I have ever had.
Fred Lehman, May 30, 2003.
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