[time-nuts] low noise multiplication to 100 MHz
cfharris at erols.com
Tue Jan 26 16:59:12 UTC 2016
One last post on this off topic subject: Eyes.
The younger folk will think eye problems amount to near
or farsightedness... maybe a little astigmatism. The
slightly older folk (37+) will know about presbyopia...
the loss of your close working focus... your arms get
Then there are the 60+ folks who know about a whole new
spectrum of problems. For you the macular degeneration,
for me the detached vitreous humor from my retina.
These result in holes in the vision, or ghosts and shadows
that float into and out of view. Fun!
Microscopes cause problems with the 60+ kinds of vision
problems because they hold the eyes steady, and accentuate
the floaters and holes. You can't just shift your eyes
and look around them because the scope needs each eye to
be accurately fixed on axis with the optical path for it
Fortunately there is a way out of this problem, and it is
a pretty cheap one too. The little CCD or CMOS video camera,
and an LCD monitor. This allows your eyes to look up, down
and around on the screen, and you get the needed
magnification, but because of the way your brain works, you
won't notice the floaters, and macular holes... You just
look around them, and your brain fills in the gaps. You do
lose your stereo optic distance clues, but there are more
expensive ways of correcting that too.
The more expensive solution is the Mantis, a large flat
screened stereo optic microscope that is supposed to help
provide the distance clues. I haven't used one, but I have
heard good things from those that have. Not exactly cheap,
but getting old has its costs.
You can work in SMD electronics when you get old.
Bert Kehren via time-nuts wrote:
> Thank you for your advice, I will print it out and when needed experiment.
> We use SMD.s and two of our tem members are very good at it, I do limited
> stuff and have some tools but also a macular hole in one eye. In designs I
> try to stay with solder able SMD's and we have projects like the AD9913
> which gets to the limit what I will consider. I did not do the soldering.
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