March 1967 Radio-Electronics
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
Mr. Forest H. Belt was,
in addition to being an editor for Radio-Electronics magazine in the
1960s, a prolific author of electronics
handbooks. His publications included theory, design, components, and
operation of radios and various equipment and gadgets - even snowmobiles and
mobile home maintenance. He published this "Can Electronics Get Much Smaller?,"
editorial article in the March 1967 issue of Radio-Electronics. On the
surface, it seems like a rhetorical question, but this statement suggests maybe
he thinks that current state of the art had about reached the practical limit of
size reduction: "There are practical limits to just how small electronic devices can become. At
least, there seem to be." The first commercially available monolithic IC op amp,
the μA702, appeared in 1963, just three years earlier. Surely that could not
have represented the pinnacle in electronic component technology. Mr. Belt
imagines miniaturizing existing vacuum tube designs with newfangled
semiconductor equivalents, but did he have the vision to imagine entire mixed
signal (analog and digital) radios on a single chip? It's hard to say, but
regardless, his capacity for prognostication far exceed mine. BTW, I could not
find a single photo of Forest H. Belt, only the one to the upper left.
Can Electronics Get Much Smaller?
By Forest H. Belt
"It is easier for a camel to go through the eye of a needle .... " That doesn't
sound easy at all, nor was it intended to. We're getting closer and closer every
day to trying it in electronic miniaturization. It seems we're reaching the hump,
however, and it's time we took a look at what to do next.
There are practical limits to just how small electronic devices can become. At
least, there seem to be.
For example, the electronics of a low-powered two-way radio can go on a chip
no larger than the head of a pin, but the microphone and speaker require many times
that space - their size determines how small a personal communications system can
For example, the electronics for an AM-FM tuner and the i.f. strips can be put
inside a module no larger than a pilot lamp, and another silicon chip added to it
can provide the entire multiplex decoder for FM stereo. But what about the tuned
circuits and - more important - the dial itself? Imagine trying to spread 10, 20,
or 30 FM stations around the small circumference of that lamp.
For example, the electronics of a stereo preamp can be put in a thimble. But,
then, who could adjust the volume, tone, loudness, balance, etc.? Even if controls
were miniscule, you'd still need knobs large enough to get a thumb and finger on.
Other limitations are inherent in microelectronics itself. Capacitances of any
large size are still very expensive, if not impossible. A watt is a watt, and even
at high efficiency there is still plenty of power lost as heat that must be dissipated.
Power supplies, even batteries, take up disproportionate space.
Is this the limit of size reduction? Have we reached the ultimate in miniaturizing
electronic systems? Not likely. There are still many ways to overcome the present
limitations - all that is required is a little different thinking. Here are some
examples of what is already in sight.
As efficiencies go higher and higher, a watt of dc power will be converted into
almost a full watt of signal power or acoustic power. Result: virtually no heat
waste. With efficiency so high, supertiny batteries will last indefinitely and be
continually recharged by microscopic cells activated by daylight or artificial light.
Tiny solid-state tuned filters will take the place of bulky LC circuits. Touch-controlled
variable tuning and small luminescent cubes with station numbers will replace huge
tuning dials. Touch switching, gate-controlled on IC chips, will take the place
of panel controls as we know them today.
There will be no need for wiring. An IC transmitter in the stereo cartridge of
your turntable will send the sound signals directly to a receiver chip in your preamplifier.
Ditto from the preamp to high-efficiency speakers, two small squares that resemble
wallpaper, each with its own tiny power amplifier.
You will be able to carry the tuner and control center for the system in your
pocket. Tiny phones in your ears, with individual receiving chips, will give you
private AM-FM-stereo listening. They will be fed by wireless signals from the preamp-transmitter
in your cigarette-pack-sized control unit. At your office, the control center can
feed your private system of speakers there. A plug-in short-wave module, about the
size of a pencil eraser, will be available for the SWLer. Similar accessories for
CB, ham, personal communications, etc., will be available.
The foregoing ideas are merely examples of what's possible. The only real limitations
on the size and versatility of electronic devices lie in the minds and imaginations
of us in the field of electronics. The limitations we endure now are only obstacles
to be overcome.
Posted November 2, 2023