Today in Science History -
When many people hear the name of
Bell Telephone Company, the first thing they think of is the court-directed
breakup of Bell System into what became known as "Baby Bells" after being sued for
monopolistic policies. What is too often forgotten - or more likely never realized
- is the immense role Bell played in the building of America into an industrial
and technology giant. Vintage magazines like this 1949 issue of Radio-Electronics
as well as many other types including The Saturday Evening Post, Popular
Mechanics, Family Circle, and many other publications commonly found
in homes, contained full-page advertisements by Bell Telephone Laboratories promoting
their work and reminding subscribers of how their hard-earned money was being invested
on improvements. Along with the Interstate Highway System, America's robust, dependable,
and high quality personal communications...
The December 1950 issue of Radio &
Television News magazine ran a series of articles on
Navy communications. This was a mere four years after the end of World War II
and right at the beginning days of the Korean War. Communist and fascist regimes
never give the world a moment's rest (some - not me - think just being nice to them
will cause them to be nice in return). Discussed here are issues still relevant
to modern outfitting of naval assets with new or updated communications equipment.
Unlike land-based systems, naval environments impose increased requirements for
ruggedness due to harsh vibration, impact, and corrosion issues. Weight added above
the waterline needs to be offset with weight below the water line to preserve stability.
Reliability and personnel training also need to be increased because being at sea
means access to replacement parts, operators, and service technicians are harder
"The trade of fake goods continues as the
COVID-19 pandemic, chip shortages and other events push more criminals to find new
ways to take advantage of unknowing buyers. Trading fake goods is bad for any industry,
but it's particularly dangerous in the industrial electronics sector, where counterfeit
components pose threats like short circuits, electrical shocks, fires, explosions
and equipment failures. 'Counterfeiters
work hard to mimic not only the product packaging but the actual product as well.
Distinguishing fakes from real parts becomes very hard for consumers..."
Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his
November 2021 newsletter that features his short op−ed entitled "C-band and
Altimeters: Bad Company? ," where he notes that even though FCC concluded that the
AVSI study "does not demonstrate that harmful interference would likely result under
reasonable scenarios," there is enough concern in the non-standardized radar altimeter
realm to raise a red flag. As Sam points out, there is a full 500 MHz separation
between the C-band wireless band and radar altimeters. Sam also presents some relevant
industry news items as well, including Amazon planning to launch Kuiper satellite
prototypes, and the DoD funding research that combines 5G and optical sensors.
color televisions hit the stores in 1954, most households could not afford one.
For that matter, most households could not afford a black and white TV, either.
By 1959 when this article appeared in Popular Electronics magazine, TV
in general was still a novelty to most people. It is amusing to read about how much
more lifelike everything would appear when broadcast in "living color." Well, duh.
It's as if it never occurred to anyone that the images previously did not contain
color like the real world did. I was born in 1958, and remember that my family's
was last of all the households I knew of to own a color television set. We never
even had a console floor model, just small tabletop pieces of junk. It was a big
deal the day I, at about age 16, bought and installed a remote rotor for the rooftop
antenna so we could receive more than three stations. There was no cable TV service
in our neighborhood...
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
Atenlab has been operating in Taiwan for
more than a decade, and has sold and installed hundreds chambers around the world.
Holistic, affordable Over-the-Air
(OTA) measurement systems perform comprehensive measurement and test in a controlled
environment. Compact Antenna Test Range (CATR) with one-touch operation supports
multiple systems - 2G, 3G, 4G, 5G - and major instrument brands. [M]ulti-probe OTA
measurement systems offer reduced time measurements over single-probe systems.
This is indeed unexpected and sad news.
Joel Hallas, W1ZR, a long-time columnist for American Radio Relay League (ARRL)
publications and an author of multiple books, has left this old world after 79 years.
Since joining the ARRL in 2010 and receiving the monthly QST magazine,
his "The Doctor Is In" column was always the first thing I read. Mr. Hallas
was a master at using EZNEC (soon to be free)
antenna simulation software and used it often to answers readers' questions. Decades
of hands-on experience setting up, operating, troubleshooting, and teaching amateur
radio subject made him an encyclopedia of knowledge. Joel's family surely knows
how admired he was by the hundreds that knew him personally and the thousands of
us who knew him through his works. RIP, Joel Hallas.
Those of us old enough to remember the classic
Simpson volt-ohmmeter (VOM) from the 1970s will look at this 1949 model appearing
in Radio-Electronics magazine and probably not notice much if any difference.
The basic case design is similar and it appears to be about the same physical size.
The selector switches and potentiometer knobs look familiar as well. The primary
difference is what is inside - a vacuum tube rather than a field-effect transistor
Simpson Model 303 is a vacuum tube voltmeter (VTVM - actually a VTVOH). Prior
to the availability of FETs with their very high input impedance characteristic
(10 MΩ or greater), a vacuum tube input stage was needed to isolate the device
(or circuit) under test (DUT) from the relatively low impedance of the resistor-based
volt-ohm meter (VOM - as with the Simpson Model 260) meter circuitry. The problem
is that a low VOM impedance...
A team of physicists and engineers at Lawrence
Berkeley National Laboratory successfully demonstrated the feasibility of low-cost
and high-performance radio frequency modules for qubit controls at room temperature.
They built a series of compact RF modules that mix signals to improve the reliability
of control systems for
superconducting quantum processors. Their tests proved that using modular design
methods reduces the cost and size of traditional RF control systems while still
delivering superior or comparable performance levels to those commercially available.
Their research, featured as noteworthy in the Review of Scientific Instruments and
selected as a Scilight by the American Institute of Physics..."
...During my last session on the cursed elliptical
machine, for some reason I was
Pi has been an enigma in the realm of mathematics and physics since it was first
recognized as being irrational The fact that the ratio of a circle's circumference
to its diameter is an inexact number has caused enormous amounts of consternation
for dogged investigators of the aforementioned phenomenon. Pythagoras is believed
to have first noticed the irrationality of certain numerical ratios when even something
as basic as the corner-to-corner diagonal of a unit square could not be calculated
to a finite precision. In some religious circles even contemplating such thoughts
caused souls to be burned at the stake for daring to assert that such an imperfection
could exist in a perfectly created world. Recall that Galileo was excommunicated
for asserting that the earth was not the center of the universe...
Rohde & Schwarz, together with ESG Elektroniksystem-
und Logistik-GmbH and representatives of the German armed forces (Bundeswehr), successfully
carried out stationary tests on the premises of the Bundeswehr Technical Center
for Aircraft and Aeronautical Equipment (WTD 61) in Manching. The
influence of rotors on radio waves was tested on two types of helicopters, operational
with the Bundeswehr, the CH53 and Tiger, as well as on the rotary wing UMAT R-350
UAV from ESG. Piloted and unpiloted rotary-wing aircraft of the Bundeswehr need
to be able to send data links through one or more rotor planes, where interference
can by caused by rotor blade modulation. The successfully completed tests demonstrated
how robust the radios are against level drops, phase shifts and diffraction at rotor
blades' edges; while digital voice and data transmission was possible at the highest
sensitivity. In addition, a comprehensive set of data was collected to develop robust
waveforms for broadband data transmission...
The term "super-radar"
would be sort of meaningless these days since just about everything is "super" anymore,
especially with regard to military, space, or aerospace systems. Not so in 1957
when this Radio & TV News magazine article appeared. Lately, when I hear the
term "super-something," I think of a really funny radio commercial with a meeting
of super-geniuses. I don't recall the exact subjects, but the chairman asks his
members for items to add to their agenda of things to do. Someone pipes up with
an idea to solve world hunger, then another suggests they design a nuclear fusion
generator to power the world with clean energy, etc. Enthusiasm exudes from the
empaneled super geniuses. Finally, someone suggests that they do whatever it is
the commercial is trying to promote (I don't remember what it is), upon which silence
falls over the room and an incredulous person says, "We're super geniuses, but we're
not super super geniuses...
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
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a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
Triad RF Systems designs and manufactures
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Here is the final installment
of C.W. Palmer's "Microwaves"
series of article in Radio−Electronics magazine. Topics for all seven parts
are shown below. Unlike the previous parts, this one discusses uses for waveguide
below its cutoff frequency for switching and attenuation purposes. Of course there
is also the filter application as well which exploits the high attenuation in the
cutoff region. Since these pieces were written in the pre-solid state semiconductor
era, vacuum tubes appear as control and amplifier devices rather than diodes and
transistors, but don't let that deter you from benefitting from the useful waveguide
characteristics lessons presented...
"Princeton University researchers have taken
a step toward developing a type of
antenna array that could coat an airplane's wings. The technology, which could
enable many uses of emerging 5G and 6G wireless networks, is based on large-area
electronics, a way of fabricating electronic circuits on thin, flexible materials.
The approach overcomes limitations of conventional silicon semiconductors, which
can operate at the high radio frequencies needed for 5G applications but can only
be made up to a few centimeters wide and are difficult to assemble into the large
arrays required for enhanced communication with low-power devices. With an airplane,
because its distance is so far, much signal power is lost. Since wings are a fairly
large area, a single-point receiver on the wing does not help but if the amount
Magnetron, photomultiplier, traveling wave,
compactron, klystron, backward wave, pencil, lighthouse, cathode ray, indicator,
nuvistor, acorn, peanut, T−R, electrostatic, cat's-eye, orithon, and loctal, are
just a few of the many types of vacuum tubes that have been and in some cases still
are in use in various types of electronic equipment. Some you have heard of, others
you probably have not. All are discussed in a series of three articles published
in Popular Electronics magazine. This is part 3, which includes operational
klystrons, magnetrons, and traveling wave tubes (radar & satellite communication),
all of which are still designed into new products today...
Exodus Advanced Communications' new model
AMP2136P-4KW is a 2.0-4.0 GHz, 4 kW pulse amplifier that is designed
for pulse/HIRF, EMC/EMI Mil-Std 461/464 and radar applications. Other frequency
ranges & power levels available - all providing superb pulse fidelity. Up to
100 μsec pulse widths, up to 6% duty cycles with a minimum 66 dB gain.
Available monitoring parameters for forward/reflected power in watts & dBm,
VSWR, voltage, current, temperature sensing for outstanding reliability and ruggedness
in a compact 10U chassis...
For some inexplicable reason I went backwards
on this three-part
Tube Family Tree series that appeared in Popular Electronics. Author
Louis Garner, Jr., starts out with the early history of vacuum tubes, beginning
with Thomas Edison's incandescent light bulb and then quickly progresses to Lee
de Forest's Audion amplifier tube, and on through the evolution of multi-grid vacuum
tubes that are specially designed for low noise receiver front ends, high power
transmitters, voltage and current regulators, video cameras, pulse forming networks,
traveling wave tubes, and many other types. There is quite a bit of information
and history contained in these three installments that will do a very nice job of
introducing you to the wonder... Here you can read
Part 2 and
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 2018 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. An intro video takes you through the main features...
Please take a few moments to visit the
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power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Radio Month" news column from the November 1949 issue of Radio−Electronics
magazine contained much interesting information. At the top of the list was an announcement
that an all-electronics system for color television implementation had been presented
to the FCC. It was one of three such systems vying for official adoption as an industry
standard. CBS (Columbia Broadcasting System), CTI (Color Television, Inc.), and
RCA (Radio Corporation of America) were in stiff competition. Here is a January
1951 Radio−Electronics article describing the three systems. Ultimately,
the NTSC forged its own standard that incorporated an all-electronic system that
was also backward-compatible with the existing black and white (B&W) system.
Also included was information about the first Philadelphia Radio Service Men's Association
(PRSMA) meeting. It was sort of an IEEE for electronic service technicians...
Now that the inestimable Bob Pease is no
longer with us to enlighten and entertain, is there a contemporary and immediately
recognizable electronics technology name you see on a magazine article, book, or
presentation? Maybe my tech literary world is pretty small, but nobody come to mind
as I write this (apologies to the many great authors I am forgetting). In the early
part of the last century, you can be sure that when the names Edison, de Forest,
Tesla, Marconi, Bell, and Morse were featured in bylines, readers took note.
Lee de Forest's 1945 article in this 1945 Radio-News magazine
on the state of the art of television was an example. No doubt many reports on TV
were written, published, and passed over, but when one of the Greats of the industry
put pen to paper it will be noticed. It worked with me...
Here is a major paradigm change from Apple's
traditional "No user serviceable parts inside" philosophy. "Apple said it plans
to launch a
self-service repair program in 2022 that would allow consumers for the first
time to fix their own iPhones and Macs with Apple parts, tools, and manuals, a prominent
shift in the consumer electronics giant's stance on the repair process. The new
Self Service Repair program will be available first for the company's most recent
iPhone 12 and iPhone 13 lineups in early 2022. It will later expand to Mac computers
featuring Apple's M1 processors, the company said on Wednesday. Under the new program,
customers will be able to fix their own devices, starting with the display, battery,
and camera modules in the iPhone, using genuine parts, tools, and repair manuals
distributed by Apple..."
This is another Radio Service Data Sheet
that appeared in the May 1936 edition of Radio-Craft magazine. I post this
schematic and functional description of the
Arvin Model 35, 8-Tube Car-Radio Receiver manufacturers' publications for the
benefit of hobbyists and archivists who might be searching for such information
either in a effort to restore a radio to working condition, or to collect archival
information. A WWW search for an Arvin Model 35 Car Radio did not turn up any
results, but I did see the unknown model shown here on an expired eBay auction.
It has a speaker front that looks like the Model 35. Installing and servicing
the earlier heavy, bulky car radios was the source of many electronic-themed comics
and articles. Some of the very earliest two-way radio sets (of which this is not)
had massive transformers, needed to generate power for the transmitter...
Double Asteroid Redirection
Test (DART) mission is directed by NASA to the Johns Hopkins Applied Physics
Laboratory with support from several NASA centers: the Jet Propulsion Laboratory,
Goddard Space Flight Center, Johnson Space Center, Glenn Research Center, and Langley
Research Center. DART is a planetary defense-driven test of technologies for preventing
an impact of Earth by a hazardous asteroid. DART will be the first demonstration
of the kinetic impactor technique to change the motion of an asteroid in space.
The DART mission is led by APL and managed under NASA's Solar System Exploration
Program at Marshall Space Flight Center for NASA’s Planetary Defense Coordination
Office and the Science Mission Directorate's Planetary Science Division..."
Most regular RF Cafe visitors will probably
not be too interested in this 1960 Popular Electronics magazine article,
but there are a lot of people who build and/or repair vintage radio gear and search
the Internet for helpful information. Having built a couple
crystal radio sets as a kid, I've always been amazed at how a few picowatts
of RF energy can be received, processed, and heard through an ear plug without the
need for external power from a battery. Speaking of crystal radios, I remember one
time while working as an electrician in Annapolis, Maryland, (prior to entering
electronics) I had a telephone handset for use in communicating with other electricians
in a building I was wiring, and it picked up the local AM radio station. A pair
of the old style handsets with carbon microphones would, with the help of a single
'D' cell in series, function as a very acceptable intercom system using two standard
electrical wires between them...
Due respect is paid throughout this technically
themed crossword puzzle to the
Greek letter "Xi," which has been dissed by the World Health Organization by
omitting it from the succession of designations for new COVID−19 variants (look
for an asterisk after the clue). Xi has been restored to its rightful place as the
14th letter in the Greek alphabet. Only clues and words are directly to RF, microwave,
and mm-wave engineering, optics, mathematics, chemistry, physics, and other science
subjects. As always, this crossword contains no names of politicians, mountain ranges,
exotic foods or plants, movie stars...
This gives a whole new meaning to "Political
Science." Vaccinated people have been generating and shedding variants of COVID−19.
WHO designates each new variant with progressive letters in the Greek alphabet,
beginning with Alpha. Until a few days ago they were up to the Nu variant. Next
came Omicron. "What
happened to Xi?" you might reasonably ask. It so happens that Xi (Jinping) is
the name of China's dictator, so "the Science" we are admonished to listen
to decided to omit it. Now we need the Ministry of Truth to replace all former references
to Xi (Ξ, ξ) with some other symbol. Let me be the first to suggest a spiked
virus icon . Damping ratio henceforth
is written as = 2.5 rather than the traditional ξ=2.5. Similarly
there is the baryon (rather than the Xi baryon),
the Riemann function, potential difference is
volts, the Scientific Research Honor Society
is now Sigma . You get the idea...