[sdiy] Learning electronics now - was Real cause of DIY death

[Robin Whittle]

I think starting with a 1940s valve radio in the late 1960s was a better
way to get to know electronics than pondering BGA devices on a
motherboard.  Without a schematic, and with a general understanding of
resistors, capacitors, transformers and thermionic tubes, it was
possible to draw and probably understand the schematic.  A tube data
book was handy, but I could look into the tube, figure out the grids,
anode etc. and see the wires go to the pins.  I had a multimeter - a CRO
would have been a lot of help.

I could modify things and have a lot of fun with a soldering iron and a
few components.  I once modified a 12AU7 flip flop module from a 1950s
computer and by accident made a splendid jammer for several VHF TV
channels - that was *most* instructive to see pretty moving herringbone
patterns on the family TV as a result of my bedroom activities!

I think curiosity often starts at the top down:

  "How does the transistor / valve radio work?"
  "How does the Gigahertz computer / DVD player work?"

  "How does the car engine work - specifically the ignition system?"
  "How does the car engine work - specifically the completely
   computerised sensor, management, fuel injection and ignition
   system?"

Sometimes it is:

  "Why does the wind blow?"
   (My initial theory was that the tree branches made it blow - and
    my physicist father was very patient and didn't criticise this
    attempt to understand.)

  "What is lightning?"

However, I believe true understanding must come from the lowest level
concepts, and be built upwards.

If one starts with an understanding of electrons, protons, neutrons and
imagines some glue which makes nuclei, then with electromagnetism and
gravity, it is possible to develop a working understanding of most
physical objects and phenomena - natural and man-made.  It is impossible
to properly understand any of the mechanisms asked about above without a
working understanding of electrons and basic physics.

Trying to build understanding by working down from high-level things is
a mess - it can only be done in terms of words and concepts which so far
have no concrete meaning, but are just a notion, a set of letters, or a
vague idea as to what it might be.  "Transistor" means a lot to me - I
see inside it and I know the various types.  "Transistor" to someone who
has never seen, felt, or worked with one, doesn't mean much at all -
certainly not enough for them to build up a sufficiently detailed mental
model of how a complete circuit works.

Developing a bottom-up understanding of complicated systems takes a lot
of work, and it requires explanations and *experiences* with people who
really understand and who are enthusiastic about physics and curiosity.

Lousy, often anti-masculine, teacher training, post-modernist
relativism, over-stimulation by video games and TV, lack of employment
opportunities for children and teenagers, everyday items being vastly
complicated and impossible to visualise the inner workings of, lack of
the 1950s to 1980s hands-on electronic magazines.

A major problem in electronics education is that the teachers often have
no physical feel for electronics or physics.  They got their
qualifications by sitting exams, and they set the exams for the next
generation.  They quite often went into teaching because they couldn't
be of use in a real electronic workplace.  A proper examination of
electronic understanding and skill would be to give a bunch of people
identically intermittently faulty items of equipment, with no schematic,
and see how they go about fixing it.  This is impractical and there is a
great deal of randomness even for one person in how long they would take
to fix it.

Paper based exams lead to an overfocus on mathematics - and this selects
those who have formal qualifications, which are mandatory if you are
going to teach people and set exams, which are therefore even more
likely to be based on mathematics then they would be due to the genuine
difficulty of examining functional electronic skills.

So the system goes round and round and before long, there is a strong
tendency for electronic education to disappear up its own mathematical
arsehole.

Here's another reason why electronic hardware might be a less energetic
area than in the past - beyond the fact that most of the gear is
designed and made overseas.  In the past, anyone with a technical bent
wound up in mechanical, electronic or perhaps civil engineering.  Radio
was the main use of electronics.  Radio TV and Hobbies magazines in the
1950s showed how to construct entire TV sets using valves, and a 5BP1
green 5" cathode ray tube.

Now, there is such a large demand in the computer field, electronic
hardware is just a small part of society's need for technical people.
Even within that field, some effort often needs to go into software
development, further detracting from the time and critical mass of
expertise to fully understand physics and hardware.

Even in the software field, things are turning to rot in some respects.
 I read an article the other day saying that newly graduated software
engineers programming embedded systems like cell-phones did not always
understand the difference between integer and floating point maths.
They generally didn't know assembly language either . . .

So that's why my new Motorola cell-phone is such a piece of crap.  It
takes the best part of a minute to boot its self-important operating
system.  Instead, I use a 2000 vintage Nokia which is ready for the PIN
in about 7 seconds.

Then there is the problem of overly-detailed, inelegant, overly
stimulating and inflexible toys.  Video games are obviously a problem
here - and so are the over-complex movie-inspired highly detailed toys,
compared to Meccano or Lego.  Meccano was useful!  My dad asked if he
could borrow part of my set, when I was 5, for his work at Harwell in
England, working on a particle accelerator!

There is also the problem of the younger generation growing up without
extensive hands-on experience with firecrackers, rockets, roman-candles,
pin-wheels etc. and without creeks, nearby wastelands and forests to
explore on their own.

Many recent urban developments don't even have footpaths, so they are
basically filing systems only safely accessible by motor car.
(Actually, some have extensive bike-paths - its not all bad.) This, plus
TV-inspired fears in parents, stops children from getting around on
their own and having a physical interaction with the world, discovering
and making things on their own.

Feeling like an old-timer bemoaning the dying of the light . . .


  - Robin   http://www.firstpr.com.au/rwi/dfish/