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Back to the Future … from vacuum tubes
to transistors to LSI IC's.
By Samuel Mitchell, CBET, DSM
Learning Objective: An appreciation for the past and respect for the development of modern day Biomedical Technicians.
1. What was it like being an electronic craftsman back in the 60s
and 70s and the challenges I faced? Growing up with the electronic revolution, from analog to digital, was like taking a mammoth diesel train (front end) engine, putting it on a go-cart and
getting not only the same performance but being able to do
things you never dreamed of. Experiencing the process of
miniaturization of electronic circuits and the passage from analog to Digital was an awesome Venture. We did some real troubleshooting and calibrating back then with a potentiometer to
turn for just about every circuit and discrete components making
up the bulk of the circuits. Today‘s ―software tech‖ may never
know the ―rush‖ of hearing and seeing a circuit ―come to life‖ as
you tweak this pot or turn that coil to fine tune the circuit. What a
feeling!! If I would give any advice to newbies, it would be to get
educated in the Big Stuff (Imaging Equipment) where you still
have a few of those opportunities to really get into the nuts and
bolts of troubleshooting and repairing. Heat and age were real
wear and tear on equipment. Vacuum Tubes were just big overgrown Transistors, serving the same functions (diodes, triodes),
often used in a lot of circuits as controllers (Power amplifiers)
where small low voltage signals controlled higher voltage
higher amperage mirrored images of those same signals. But
with the advent of the Transistor and Integrated Circuits (ICs),
also heat problems were brought to a minimal value and age
problems became almost non-existent. However, the new semiconductors and integrated circuits put a new stress level on the
―mom and pop‖ tech shops and we were scrambling to keep up.
Unless you live through the actual pace of arrival of new technology, words can‘t do justice to the excitement we experienced
as we awaited each new development. Now we have SO MUCH
stuff on the landscape it is hard to develop that same experience. Of course, electronic schools were generally available
into and through the 60‘s and 70‘s. It was like a patchwork quilt
of local trade schools, colleges and some of the National correspondence schools offering some types of electronics courses.