by Bryan Bergeron, Editor by Bryan Bergeron, Editor
DEVELOPING
Nostalgia and the
Amnesia of Time
I make a habit of attending the MIT flea market, held
in Cambridge once a month in the summer and fall. I
always find what I’m looking for: feelings of nostalgia.
There’s inevitably someone selling a HeathKit transmitter,
a Simpson multimeter, an analog Tektronix o’scope, or
some other equipment like the ones I either used to own
or longed for. Now, I can afford to buy just about anything
at the market, but I don’t have the time to devote to
refurbishing something that went out of production a few
decades ago.
Life was certainly simpler when a receiver contained
just a pair of transistors or (like a CW transmitter) only a
single tube. Electronics were certainly more rugged when
everything was built on a steel or copper chassis, but not
necessarily better. Take the flash bulbs in the
accompanying photo, for example.
The bulb in the foreground — about the size of a
refrigerator bulb — is all set for ignition. The one in the
background is recently fired. Both are built like tanks. Prior
to igniting the bulb with a 6V battery, I dropped it onto a
hardwood floor from about three feet. It just bounced.
Trouble is, now I have to dispose of that bulb. Who knows
what heavy metals are on the other side of the glass? Like
those old receivers and transmitters built on a steel
chassis, indestructible isn’t always a good design goal.
While I sometimes long for the simpler days when
perhaps two dozen discrete components could be used to
create just about anything, I also remind myself that there
were real limits to what could be accomplished. A tube-type guitar amp was certainly easier to fix than a modern
solid-state amp, but there were few — if any — onboard
special effects. Plus, replacing the output tubes every
three or four months was expensive.
I think that time has smoothed the rough edges of the
older electronics technologies. Point-to-point wiring was
fun, easy to trace, and allowed the components to cool by
airflow. There was little that could be done for
miniaturization, however. Some innovations are just cool
because they provided a glimpse of things to come. Take
the first Motorola walkie-talkies. These payphone-sized
devices paved the evolutionary path to modern cell
phones.
Nostalgia aside, is there any practical value in reexamining the electronics of yesteryear? Of course. There
are lessons to be learned about layout, construction,
For example, modern high-end
tube amp manufacturers avoid
ordinary audio-grade electrolytic
capacitors in favor of sealed,
computer-grade capacitors that have
life expectancies of 100+ years. If
you’ve ever refurbished a tube-type
audio amp, you know that the
electrolytic capacitors are the first
components to go.
We’ll continue to feature
nostalgic circuit projects in
Nuts & Volts. Even if the electronics
discussed predate your parents,
I think you’ll find them worth
reading. Some of the lost arts are
worth remembering. NV
PERSPECTIVES
6 September 2013