People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular
Electronics was published from October 1954 through April 1985. All copyrights are hereby acknowledged. See all articles from
Believe it or not, cathode ray tubes (CRTs) are still manufactured
for specialty products and for replacement parts. Even with
a high level of automation, there are still steps in the manufacturing
process that require human handling. A comparison between CRT
plants in the USA and Germany show the similarity but distinctly
different processes in a Sylvania and Telefunken operations,
respectively. The photos shown are from an article in a 1958
edition of Popular Electronics. At the bottom of this page are
videos of a modern CRT manufacturing process and a CRT recycling
effort. As you will see, properly recycling a CRT is about as
manually intensive as manufacturing one (but with no quality
control and functionality concerns). I am not sure where the
profit is in recycling unless inflation over the 10-20 years
since manufacturing makes the value of materials worth the effort.
A très cool documentary film on the designing and manufacturing
RCA Victor television sets is at the very bottom.
A TV Tube: As It Is Made - In Germany - In U.S.A.
U. S. photos taken at Sylvania Electric plant at Seneca Falls
German photos taken at the Telefunken Company plant at Ulm,
1 Bulb washing with hydrofluoric acid, then
water, is done on assembly line at Sylvania, and on circular
"washautomaton" at Telefunken. In this and following steps,
the process in both plants is generally automatic, but workers
move bulbs from one line to next.
2 After "screen settling," bulbs filled with
a phosphor solution are "poured" off as they move along vibration-free
conveyor belts. When the fluorescent coating has dried, a thin
lacquer coating is applied in the same manner, to serve as a
base for aluminizing - the next step.
3 To assure brighter screen and clearer raster,
both plants apply an aluminum coating to the inside of the bulb.
A small piece of aluminum is heated to incandescence in the
evacuated bulb, depositing a micron-thin film of the metal over
the interior lacquer coating which was applied earlier.
4 Baking in lehr (oven) removes lacquer coat,
leaving a smooth aluminum coat.
5 The sealing process is the marriage of bulb and gun, effected
in both plants on a circular assembly line. While the German
photo does not show it, the bulbs must be placed on the line
by workers, as in the Sylvania shot. Sealing is automatic as
is following inspection process.
6 Evacuating the tubes at high temperature
is accomplished on a screened-off line as a safeguard against
implosions, which occur infrequently. "Getter" is then flashed
to absorb foreign gases, after which the tubes are aged and
tested. Inspection and packing are last.
Here is how CRTs are made today (this is not high volume
How It's Made: Cathode
Ray Tubes (CRTs)
Now, here is how they
are properly disposed of after their useful lifetime.
This is an RCA Victor
Television Production Plant Documentary - Dig the Test Equipment!
If you take the time to watch this video of the RCA Victor
television development process, you will be impressed with the
amount of engineering that went into those units. By contrast,
a large percentage of the manual design and testing in today's
electronics is done on a computer with simulation programs
(typically NOT in America).
Huge databases of component characteristics data are available
for just about every electrical, mechanical, and chemical parameter
of every type of material. All of this significantly cuts down
on design and development time needed for getting products to
Every capacitor, resistor, inductor, transformer,
tube base, connector, cable, and every wire connecting all the
parts together had to be installed by hand back in the era.
The same goes for mechanical assemblies. There were no automated
test protocols for checking accelerated lifetimes and FCC compliance
(see the OATS* setup in the video). Documentation was drawn
on a drafting board with a pencil and typed on paper with typewriters.
Promotional material and user manuals were laid out on a cutting
and lay-up board where text and graphics needed to be brought
together. It was a lot of work that kept a huge army of highly
skilled engineers, technicians, draftsmen, stylists, and craftsmen
employed, many of whom had cut their teeth during the WWII and
Korean War defense contracting eras.
America and most
other Western countries were powerhouses of intellectual and
physical creativity hands-on genius. Nowadays our factories
are empty and the national know-how is focused on playing video
games and perfecting ways to have the government give you other
people's hard-earned stuff.