|
 What drew my attention with this
P.R. Mallory & Company advertisement was not an actual
electronic component that they are most noted for - potentiometers, capacitors,
switches, metal alloys, and of course batteries (later renamed Duracell). Philip
Rogers Mallory began his company manufacturing tungsten wire for lamps. Rather what
interested me was the huge variety of standard potentiometer and rotary switch extension
shafts. Unlike modern electronics where pots and switches are typically mounted
to the enclosure with wires running to the circuit assembly, many...
 The failure to recognize
Nathan B. Stubblefield as the primary inventor of radio is a classic example
of how institutional power, financial interests, and the legal machinery of the
telecommunications industry tend to favor those with corporate backing over solitary,
unconventional inventors. Stubblefield's technology, which he demonstrated as early
as 1892, utilized induction and conduction through the earth and water rather than
the electromagnetic wave propagation (Hertzian waves) that ultimately became the
standard for modern radio. Because his method was effective only over relatively
short distances and functioned on different physical principles, it was eclipsed
by the work of Guglielmo Marconi. Marconi was the superior marketing force. He was
backed by a massive corporate infrastructure and was savvy in securing international
patents...
 Author T.A. Gadwa employs a
standing wave mechanism analogy that I don't recall having read
before - that of a dam on a river. The river is the transmission line with a lake
as the source and then he imagines a dam load. The dam standing waves, per his description,
have phase and amplitude characteristics that depend on how tall the dam wall is
relative to the surface height of the dammed river. An extensive array of graphs
is provided showing how the current of the dam standing waves react to the dam transmission
line termination impedance...
 Here are a couple more
electronics-themed comics, this time ones that appeared in the October 1951
edition of Radio & Television News magazine. When is the last time
you saw a comic in a technical magazine? Note the AC power cord attached to the
"portable" television. Television was a big deal in the day (I assume the "His"
on the guy's towel implies that "Hers" is at the other end of the power cord). Color
TV was not commercially available until a few years later. Nowadays, a person would
have a smartphone, tablet, or notebook computer while on the can. There is a huge
list of other comics at the bottom of the page...
 "Once upon a time in Europe, television
remote controls had a magic
teletext
button. Years before the internet stole into homes, pressing that button brought
up teletext digital information services with hundreds of constantly updated pages.
Living in Ireland in the 1980s and '90s, my family accessed the national teletext
service - Aertel - multiple times a day for weather and news bulletins, as well
as things like TV program guides and updates on airport flight arrivals. It was
an elegant system: fast, low bandwidth, unaffected by user load, and delivering
readable text even on analog television screens. So when I recently saw it was the
40th anniversary of Aertel's test transmissions, it reactivated a thought that had
been rolling around in my head for years..."
 I have a confession to make regarding the
puzzle titles. While all
RF Cafe crosswords do in fact use only my hand-entered dictionary
of terms and clues (literally thousands accumulated over the years) that pertain
exclusively to science, engineering, chemistry, physics, mathematics, astronomy,
etc., the choice for a particular title is to help attract search engines to the
page. There is nothing deceptive going on, just an attempt to exploit the nature
of search engine algorithms that rank pages based on meta tags coinciding with relevant...
 Sam Benzacar, of Anatech Electronics, an
RF and microwave filter company, has published his
April 2026 Newsletter that, along with timely news items, features his short
op-ed titled "Bell Labs in Murray Hill Celebrates." Sam, whose company is located
not far from Murray Hill, extolls the many discoveries and inventions that took
place there since its founding in 1925 as Bell Telephone Laboratories. It was originally
a subsidiary of AT&T and Western Electric, later becoming part of Lucent Technologies
and Alcatel-Lucent before Nokia's acquisition in 2016. Sam reports on the facilities'
recent 100th anniversary celebration. The list of accomplishments would will volumes...
 The transformative role of ferrites - crystalline
structures composed of iron oxide and metallic additives - in advancing modern electronics,
is reported in this 1961 Electronics Illustrated magazine article. Ferrites
uniquely combine magnetic properties with electrical insulation, enabling high efficiency
at frequencies where standard iron cores fail due to eddy current losses. This "electronic
wonder material" proved critical for television development, allowing for larger
picture tubes through efficient flyback transformers and deflection yokes. Furthermore,
ferrites revolutionized computing by providing reliable, compact memory cells, replacing
failure-prone vacuum tubes in machines like the Whirlwind I. Beyond these core
applications, the material facilitates innovations such as ultrasonic ...
 "In 1627, a year after the death of the
philosopher and statesman Francis Bacon, a short, evocative tale of his was published.
The New Atlantis describes how a ship blown off course arrives at an unknown island
called Bensalem. At its heart stands Salomon's House, an institution devoted to
'the knowledge
of causes, and secret motions of things' and to 'the effecting of all things
possible.' The novel captured Bacon's vision of a science built on skepticism and
empiricism and his belief that understanding and creating were one and the same
pursuit. No mere scholar's study filled with curiosities, Salomon's House had deep-sunk
caves for refrigeration, towering structures for astronomy, sound-houses for acoustics,
engine-houses..."
 Werbel's new
WM2PD-1.5-20.5-S-ECO, 2-way power divider covers 1.5 to 20.5 GHz and is
designed for engineers who need wideband performance in a compact, cost-efficient
package. Optimized for size, bandwidth, and manufacturability, it is well suited
for high-volume applications, lab use, and general-purpose signal distribution where
extreme port match is not required. Designed, assembled, and tested in the USA.
"No Worries with Werbel!"
 The radar system I worked on in the USAF
used two early memory types described in this 1956 Popular Electronics
magazine article. In fact, the radar was designed during that era, so it is no surprise.
Our IFF secondary radar had a whopping 1 kilobyte of
magnetic core memory in its processor circuitry. It consisted of 1024 tiny toroids
mounted in a square matrix with four hair-width enamel coated wires running through
them as x and y magnetization current lines, sense, and inhibit functions. If my
memory serves me (pun intended) after three decades away from it, the TTL circuitry
(no microprocessor) stored range values to calculate speed and direction from sample
to sample. The other memory type was a mercury acoustic delay line contraption having
a piezoelectric transducer at one end to launch an electrical pulse along its length
and another transducer at the other end to convert back to an electrical pulse...
 These are the schematics and parts list
for vintage vacuum tube radios
Westinghouse Model H-133;
Arvin Models 150TC, 151TC; and
Admiral Model 7C63, Chassis 7C1 as they appeared in the December
1947 issue of Radio News magazine. I scan and post these for the benefit
of hobbyists and historians seeking such information. As time goes by, there is
less and less likelihood that records of these relics from yesteryear's archives
will be made available. As with all historical information, it takes someone with
a personal interest in preserving the memories in order to fulfill the mission...
 KR Electronics has been designing and manufacturing custom filters
for military and commercial radio, radar, medical, and communications since 1973.
KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop,
equalizer, duplexer, diplexer, and individually synthesized filters for special
applications - both commercial and military. State-of-the-art computer synthesis,
analysis, and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Designed and
manufactured in the USA. Please visit NIC today
to see how we might be of assistance.
 Here is another electronics quiz for you
to try. Intuition from experience goes a long way here, but if all else fails you
can work out the details of the rectifier circuits to determine
which lamp received the most current. Keep in mind that the diode
symbols are not LEDs; it is the "A," "B," and "C" symbols inside circles
that are the lamps whose brightnesses are being considered. LEDs did exist at the
time this quiz was created in 1969, but the circuits would perform differently if
in fact LEDs were used for double duty of rectification and illumination...
 The more things change, the more they stay
the same. That saying applies to many recreational activities. Pick up a copy of
QST magazine that was published in the last year and look at
reader comments and you will find laments about the dwindling
participation of youngsters, an increased degree of incivility and rule breaking
during engagement, the high cost of getting into the hobby, yadda yadda yadda. I
witness it regularly in the model aircraft world, too. That is not to say the issues
are not true or irrelevant, just that they are persistent. Each generation, it has
been said, tends to think...
 I have long-maintained that the vast majority
of electrical problems on consumer products can be attributed to bad connector or
switch contacts. Just yesterday, I restored a 1970's-era TI talking kids' toy to
working order just by cleaning the plug-in program module and mating motherboard
contacts. RF Cafe website visitor / contributor Bob Davis sent this suggestion for
curing intermittent or non-responsive front panel buttons on test equipment and
other electronic gear like radios, remote keypads, games, tools, vehicles, keyboards,
locks, etc. His problem was with a R&S spectrum analyzer. He found a solution
from ButtonWorx, who manufactures replacement
pressure contacts for a large range of products. Some are entire arrays to replace
original parts, and others are individual switches for custom requirements.
 You wouldn't know it from the schematic,
but this
Coronet
Model C-2 tabletop radio has a very unique feature: The tuning scale/pointer,
and volume and tuning knobs are on the top of the case, that is, the face of the
radio points upward when properly displayed. When searching for photos of the Coronet
C2, I found a few examples where the radio was sitting on a surface with the face
situated vertically like a standard model, but the feet are clearly on the side
opposite the face. The schematic and parts list for the Coronet C2 radio appeared
in the February 1947 issue of Radio News magazine. There are still many
people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information. I keep a running list
of all data sheets to facilitate a search...
 Have you noticed that every time a shooting
or other attack event occurs - especially pertaining to "R" targets - the quality
of the video looks like something from the 1970s, or of a UFO sighting? Most private
surveillance cameras in homes, cars, and businesses - even traffic cams - have resolution
and full color so good you can distinguish faces and even identify brands of clothing,
weapons, etc. This is a frame from the attempted assassination attempt this weekend
at the White House Correspondents Dinner. The perp, a celebrated "Teacher of the
Month" from California, rushed the security point with multiple weapons. Conceal
carry, do training, and watch your six.
 In the early 1950s, the U.S. Navy built
what was at the time the world's largest and most powerful radio broadcast transmitter
station at the
Jim Creek Naval Station on Wheeler Mountain in Washington state.
Its 1.2 MW, 24.8-to-35 kHz VLF transmitter (call sign NLK) can reach anywhere
in the world, even to submarines. A half wavelength at 24.8 kHz is 19,830 feet.
Photos indicate that the transmitter is located in the middle of a dipole arrangement.
"Catenary cables," if you are unfamiliar with the term, refers to the sagging shape
assumed by both the antenna cables and the tower support cables. "Catenary" stems
from the word "chain" since it is in the form...
 Carbon tetrachloride (CCl4) was
a common cleaning agent used commercially through about the early 1950s when it
began receiving a lot of bad press due to a linkage to severe kidney damage from
exposure even in vapor form. I notice that Mac mentions having read an article about
the potential danger of "carbon-tet" in an edition of Radio & Television
News magazine, not coincidentally the publication where the "Mac's Radio Service Shop" series appears. He also mentions a publication
called International Projectionist, which included instructions for cleaning
movie film with carbon tetrachloride, and had...
 It is amazing to me how many times I read
an article, whether in a vintage magazine like this 1947 issue of Radio News,
or a current edition of QST, how when discussing maximum power transfer
from a source to a load, the author states merely that the load impedance must equal
the source impedance. The fact of the matter is that the source and load impedances
must be the
complex conjugates of each other in order for maximum power transfer
to occur. That is to say that if the source has a complex impedance of R + jX, then
the load must have a complex impedance of R - jX (and vice versa)...
 Unlike today when resources of all types
seem to be endlessly available, during World War II countries needed to collect
and recycle much in the way of metal, rubber, cloth, and other basic materials for
re-purposing into products used in fighting the enemy. Media coverage of bottle,
metal, and tire drives showed children pulling Radio Flyer wagons loaded to overflowing
with such items gathered from trash piles and soliciting neighborhood residents
for anything that could be spared. Raw materials were not the only type of items
needed, however. "Use
it up, Wear it out, Make it do, or Do without" was the slogan. Finished goods
like electronic components - vacuum tubes, transmissions cable, transmitters and
receivers, tuning capacitors, d'Arsonval meter movements, and other parts -
were sorely needed by manufacturers both for building new equipment and for servicing
damaged gear. After the war was won, the War Assets Administration...
|
 • 2026
PC Sales down 11.3%, Tablets down 7.9%
• Starlink
Becoming Mainstream Option
• U.S.
Engineering
Ph.D. Programs Losing Students?
• What
Hormuz Exposed About Semi Supply Chain
• Broadband
Equipment Market Set for 2026 Rebound
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 You wouldn't know it from the schematic,
but this
Coronet Model C2 tabletop radio has a very unique feature: The tuning scale/pointer,
and volume and tuning knobs are on the top of the case, that is, the face of the
radio points upward when properly displayed. When searching for photos of the Coronet
C2, I found a few examples where the radio was sitting on a surface with the face
situated vertically like a standard model, but the feet are clearly on the side
opposite the face. The schematic and parts list for the Coronet C2 radio appeared
in the February 1947 issue of Radio News magazine. There are still many people who
restore and service these vintage radios, and often it can be difficult or impossible
to find schematics and/or tuning information. I keep a running list of all data
sheets to facilitate a search...
 If you had to guess, what would you say the
image to the left represents? Part of a printed spiral inductor? How about a printed
antenna for near field communications (NFC)? Need a hint? OK, the object is part
of a project that Alexander Graham Bell, his cousin Chichester Bell, and Charles
Sumner Tainter worked on in their Volta Laboratory Associates labs. No, it's not
a neatly wound coil of telephone cable. It is a section of an audio
recording
etched on a glass platter in November of 1884. After being stored at the Smithsonian
Museum for 130 years, this and a few other recording media was lent to the scientists
at Lawrence Berkeley National Laboratory with hopes that they could apply newly
invented noninvasive, non-contact techniques to scan the disc and use software algorithms
to recover the data. Thomas Edison had introduced his phonograph to the world in
1877...
 Windfreak Technologies is proud to announces
the availability of our
FT108, an innovative
programmable bidirectional filter bank spanning a frequency range of 5 MHz
to 8 GHz in 15 bands. Band selection can be controlled through USB, UART or
at high speeds through powerful triggering modes. Each unit is factory tested via
network analyzer with unique data stored in the device to help with its use. Crossover
frequencies are stored so the user can send a frequency command and the FT108 will
utilizes Intelligent Band Selection logic to automatically toggle the optimal
filter path based on minimum insertion loss. Readback of FT108 insertion loss at
any frequency between crossover points allows for easy amplitude leveling...
 Here are a couple electronics circuit analysis
problems to prime you for the week ahead. They are from the August 1964 "What's
Your EQ?" challenge in Radio-Electronics magazine. EQ, by the way,
is for Electronics Quotient, as in IQ (Intelligence Quotient). Some others are in
the list below. In the Autotransformer problem, I made the assumption that the secondary
tap was actually in the middle (as drawn), so that there was an equal number of
turns above and below the tap. That proved to be a good assumption since it validated
my answer (not difficult if you know the basics of autotransformers). The other
problem, "Case of the Lost Energy," is a variation on similar ones containing a
potentially (pun intended) non-intuitive missing energy being stored in capacitors.
I'll admit to not having worked through it yet. You'll probably figure it out in
no time...
 A 720-line HDTV display is made up of 1,280 vertical
lines and 720 horizontal lines of pixels, which gives a total of 921,600 pixels. A 1080-line
HDTV has 1,920 vertical lines and 1,080 horizontal lines, for a total of 2,073,600 pixels.
In 1969, a 230 vertical line by 230 horizontal line
electroluminescent (EL) flat-screen television display with 52,900 pseudo-pixels
was considered a big deal - and it was since it was the starting point for digital flat-screens
of today. Interestingly, while the "pixel" distribution was square, the actual display
retained the standard 4:3 aspect ratio, meaning horizontal element width was 33% greater
than the vertical element. Since each EL element was addressed individually, there was
no ability of a picture element to be shared by adjacent "pixels," so displaying a circle
would result in a very pixelated picture...
 Electroluminescent
(EL) devices were patented by General Electric back in 1938, but it was not
until the 1960s that the fabrication process, involving copper-doped zinc sulfide
(ZnS) as the light-emitting compound, had developed
to the point where high volume production was feasible. Early EL displays exhibited
short lifetimes and low efficiencies. EL panels are also referred to as light-emitting
capacitors because of their construction geometry. Some of the first commercial
applications for such EL panels were as back lighting in automobiles. Electroluminescence
can also be obtained in semiconductors in the III-V group class like indium phosphide
(InP), gallium arsenide (GaAs),
and...
 "PCBs? We ain't got no PCBs in our TV sets†...
We don't have to give you no stinking PCBs." That is effectively what the Zenith
television advertisement from a 1958 edition of Radio-Electronics told its potential
customers. According to the Zenith communications department, even though their
head R&D guy, Dr. Alexander Ellett, was "the
daddy of printed circuit boards," they stuck with the traditional point-to-point
wiring in all their TV chassis. I have to agree with them from a troubleshooting
and component replacement perspective. There's nothing easier than heating a solder
lug or terminal post to unwrap a leaded R, L, or C either to measure its value,
isolate it from the rest of the circuit for making tests, or to replace it. There
is no worry about solder splatter or bridges, overheating the PCB material to cause
delamination, or lifting metal traces from the surface. There is also no issue with
getting a component lead out of a plated-through hole. Yes, of course modern circuits
need multilayer, high density circuit boards...
 The ARRL (American Radio Relay League) might
be considered as one of the first app developers. At 50¢ and $1 per app, the price
was in-line with one of today's typical not-for-free Apple or Android app. A user
willing to shell out $4 for all six had at his fingertips calculators and reference
tables for capacitive and inductive reactance, resonant frequency, gain and power,
conductor amperage, transformer turns ratio, resistor, capacitor, and inductor series
and parallel combination, and other values. These six apps, dubbed "Lightning Calculators,"
were comprised of bit of cardboard, plastic, and a metal eyelet, not data bits.
Here is a for-real Type B "Lightning Calculator," graciously provided by Joseph
Birsa, N3TTE...
 When you see an article title such as this
one from at 1947 issue of Popular Science magazine titled "Electronic
Color Television is Here," you might think well duh, what other kind of TV would
there be other than "electronic?" If you had been around at the time and were aware
of developments in color television, you would know that there were a couple variations
of electromechanical systems being considered. In fact, RCA and CBS had a rotating
color wheel (red, green, and blue segments) which rotated in front of the video
detector tube to separate colors for comprising the composite signal, and then a
similar setup for projecting onto a display screen. Fortunately, the all-electronic
NTSC format won the competition. Even so, because of complexity and reliability
concerns, the color TV cameras that flew on Apollo 10 and Apollo 11 (the first moon
landing) in 1969 used the color wheel approach. The RCA scheme reported here uses
stationary mirrors, which went away before the NTSC standard became law...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
 Westinghouse's motive for dubbing the
Model WR-8 the "Columnaire" is apparent when you see a photograph of it. This
model also had a -R version with remote control. The remote, though, has a cable
attached to it; it's not wireless like today's remote controls. There are some very
nice photos of a fully restored WR-8-R version on the AntiqueRadios.com website
forum. Look about half-way down the page. Near the bottom of the page is a copy
of an advertisement for the Westinghouse WR-8 with a price of $193 (~$3,563 in 2022
money per the BLS Inflation Calculator). The fundamental circuit of these receivers
is the WRV5 receiver chassis and power pack shown in Data Sheet No. 29. The model
WR-6 is a highboy; its circuit is the same as used in the WR-6, except as modified
for tone control. The Model WR-7 is similar to the model WR-6, except as modified
for an electric phonograph...
 The exact details and methods of raising
financing and seed money for both new and existing businesses have changed over time,
but the fundamentals have not changed. Most important is to have a product or service
that people think they need or can be convinced that they need - the "create a need and
then fill it" philosophy versus "find a need and then fill it." Today's entrepreneurs
have the benefit of the Internet and its broad reach that makes just about anyone "discoverable"
via angel investment groups, Kickstarter type individual investors, and access to countless
numbers of establishment banks. Social networking with total strangers might provide
the spark needed to set an effort on fire. Overnight successes...
 It is doubtful
that as many people today build their own
stereo speaker enclosures as was the case
back in the 1950s through about the 1970s. During those decades stereo equipment
was a really big deal, as evidenced by the large number of articles in technical
and hobby magazines. I have posted a couple dozen articles on the subject here on
RF Cafe. Topics included equipment reviews and feature comparisons, troubleshooting
and alignment, modifications to commercial units, build-it-yourself projects, optimized
room layout and construction, and even advice on how to best enjoy your stereo system.
Lots of comics appeared in the magazines as well poking fun at how a stereo enthusiast's
family members and neighbor might not appreciate the ear drum-busting power capability
of your system. There were also quizzes like this one on speaker enclosure baffle
design...
 As is the normal modus operandi (MO) of
John T. Frye with his "Carl &
Jerry" series of techno-dramas, this "Too Lucky" episode combines adventure
with electronics to teach a lesson in the process of entertaining with a great story.
If you're a fisherman, you'll particularly enjoy this one. I have to admit to not
knowing about this method of "electrofishing" (although not called by that name
here) for drawing fish to a high voltage alternating electrical field and then capturing
them with a net once close enough to be paralyzed (stunned). A process called "galvanotaxis"
which causes uncontrolled muscular convulsion in the fish causes them to swim towards
the source...
 Mr. Wilfred Jensby wrote an incredibly detailed
article for the November 1966 edition of QST that delves deeply into the
subject of using
transmission lines as distributed circuit elements. I did a search on his name,
figuring that he likely had other publications of like sort, but nothing was found.
Information contained herein is similar to what you would expect to find in a Master's
level engineering course textbook or in a $100+ technical book from Artech House,
Cambridge University Press, John Wiley & Sons, etc. The brain-zapping equations
are omitted with only a great, layman-level discussion of the concepts and some
really nice illustrations and graphs. This is definitely an article you will want
to check out and pass on to colleagues...
 The story from a 1958 issue of Radio-Electronics
magazine documents development of the "transistom"
device back in the 1958 timeframe. Keep in mind that it was just a decade earlier
that Mssrs. Bardeen, Brattain, and Shockley introduced the transistor amplifier
to the world. The transistom was basically a 3-terminal transistor with two additional
leads for a revolutionary power source built from radioisotopes of magnesium and
manganese. In the day, school kids, including me, were handed blobs of liquid mercury
to inspect and pass around in class, demonstrating how relatively ignorant we were
about things we now consider to be extreme health hazards. Accordingly, encapsulating
radioactive material in consumer devices was not a concern. The complete absence
of transistoms in the marketplace today speaks volumes about its success. Then again,
the month of publication of this article, and its author, might have something to
do with it...
 This is just one of many full-page advertisements
in the December 1950 issue of Mechanix Illustrated magazine for
electronics service schools. There was also Coyne Electrical & Television-Radio
School, De Forests' Training (yes, THAT de Forest), deVry Institute, and
a couple others. Electronics for home and industry was big business following World
War II, both from the enormous amount of new knowledge gained in components,
circuits, and manufacturing, and from the near total lack of consumer products being
turned out by manufacturers while wartime rules mandated that all available resources
be dedicated to the effort. In fact, immediately after the end of the war, aircraft,
electronics, automobile, and many other industries went into a major downturn as
government contracts were pulled overnight, leaving companies high and dry with
no orders and factory floors which had been reconfigured to meet government demands.
Of course those companies and employees enjoyed handsome profits and all the work
they could handle for half a decade, so they couldn't complain too much...
 Whoa, it's a good thing I read these articles
prior to publishing them, lest some soul unfamiliar with this topic be lead to the
wrong conclusion! Keep in mind that this article was written in 1932, prior to the
development of the quantum mechanical model of the atom, but on the other hand,
Ernest Rutherford and Niels Bohr developed their model in 1913, so the relevant
information was available. The Rutherford-Bohr model of the atom suggested a nucleus
comprised of positive masses called protons, each of which carries a charge of +1
unit, and neutrons with no net charge. Surrounding the nucleus were orbiting masses
called electrons, each of which carries a charge of -1 units. Accordingly, the net
charge of an atom was the sum of protons and electrons, with unionized atoms having
a net charge of 0 (zero). Neutrons, carrying no charge, have no effect on the overall
atomic charge. Modern science says quarks, three of which make up each proton and
neutron, have individual charges of +1/3, -1/3, +2/3, or -2/3, thereby determining
the particles' net charges...
 In the middle of the last century, progress
in television and radio technology was the focus of public attention, similar to
news of the latest advances in smartphones and Wi-Fi-connected gadgets are today.
Then, it was the installation of
microwave relay networks for long distance telephone and television
interconnections as reported in this 1948 issue of Radio-Craft magazine.
Now, media headlines tell of new 5G cellular network equipment and small cell stations
being installed around the world. New portable pocket radios using a single low
voltage "peanut" vacuum tube or a germanium transistor are today's iPhones, smartwatches,
and IoT-connected appliances. The item that caught my attention was mention
of General electric (GE) issuing warnings that radar-equipped cargo airplanes should
not be used to transport photo-flash camera bulbs because experiments showed exposure
to certain frequencies and power... |
