See Page 1
| of the April 2023 homepage archives.
Friday the 21st
""A study published in Nature Communications
highlights the progress made in practical quantum sensing by a team led by academician
Guo Guangcan and Prof. Sun Fangwen from the University of Science and Technology
of China (USTC) of the Chinese Academy of Sciences (CAS). The team utilized micro
and nano quantum sensing, coupled with local electromagnetic field enhancement at
deep sub-wavelength scales, to study the detection of microwave signals and wireless
ranging, achieving a positioning accuracy of 10-4 wavelengths. Radar
positioning technology based on microwave signal measurement is widely used in activities
such as automatic driving, intelligent manufacturing, health monitoring, and geological
exploration. In this study, the research team combined
quantum sensing of solid-state systems with micro/nano resolution and deep subwavelength
localization of electromagnetic fields to develop high-sensitivity microwave detection
and high-precision microwave positioning technology..."
In the continuing saga of
Carl and Jerry, our two young electronics hobbyists visit a college radio station
where the manager gives a tour while explaining the technical aspects of the equipment.
RF bridges, hybrid junctions, oscillator coils and plate-tank pi-networks, cue amplifiers,
limiter amplifiers, patch board, power supplies, and a lot of other terms that cause
RF Cafe visitors to salivate are woven into the story. Carl and Jerry are surprised
to learn that the transmitter output power is high enough that dormitory residents
can pick up the signal with "only a pair of earphones clipped across a 1N34 diode"
as well as with a standard AM radio. In fact, that's the whole point of the story
because the broadcast is not over the air, but via the campus' AC electrical system
- hence, "wired wireless..."
Two years after the U.S. abandoned Afghanistan
in 2020 and left more than
$60,000,000,000 worth of equipment in the Taliban's hands (and still some U.S.
citizens trapped there), China is now planning to
extract oil and minerals - including lithium from vast deposits. Now that the
banned girls from attending school, there will be plenty of labor available
to wade through the artificially flooded plains created to process the lithium.
That lithium will then go into everything from cellphones to electric cars. Since
China still enjoys developing country status, they are free to generate as much
pollution as required to bring them up to the living standards of privileged countries
like America - like for instance in Chicago, Atlanta, and Los Angeles. What can
possibly go wrong?
"The boy and his father had just witnessed
a demonstration of one of the most promising and fastest developing technological
devices ever conceived by man - the laser. In only three whirlwind years, the laser
- which gets its name from the initials of
Light Amplification by Stimulated Emission of Radiation - has moved out of the
theory stage, out of the laboratory curiosity category, and into a whole new, exciting
world of applications." That's the opening of an article in the July 1963 edition
of Popular Electronics. I remember when ruby lasers were the the rule rather than
the exception for lasers. Power levels were measured in units of "Gillettes" in
reference in the number of razor blades they could cut through. Next came chemical
lasers with power levels in the megawatts and now even gigawatts that can take out
ICBM warheads as they reenter the atmosphere and can fry orbiting satellites. At
the same time the realm of semiconductors and microcircuits was turning out devices
on the opposite scale for use in communications, inertial navigation, and boardroom
presentation pointers. This article is an extensive recounting in layman's terms
the state of the art in 1963...
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customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
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equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today - and don't miss the blog articles!
Thursday the 20th
Hmmmm, I'm not quite getting the comic on
page 59, unless it's referring to the remoteness of the "customer." In 1960 when
it appeared in Radio-Electronics magazine, some would have likely considered
it scandalous. The editor probably justified the theme the way National Geographic
did their jungle tribeswomen exposés (pun intended). I like the page 78 comic with
the unique typeface used to represent the guy's hurt foot. In 1960, such characters
would require hand-drawing or the special
Dial−A−Type typewrite ball sold to enable direct typing onto paper. On page
118, what kind of clip is that? (get it?). 1960 was also the era of wireless remote
control of everything, as implied in the page 128 comic. Enjoy.
"Technically, panoramic reception is defined
as the simultaneous visual reception of a multiplicity of radio signals over a broad
band of frequencies. In addition,
reception provides an indication of the frequency, type and strength of signals
picked up by the receiver. Deflections or 'peaks' appearing as inverted 'V's on
the screen of a cathode-ray tube." It is the kind of display that radar operators
at Pearl Harbor were using when they mistook wave of incoming Japanese bombers for
a squadron of B-17s from the mainland. The panoramic receiver is not a wartime development,
experimental models having been produced just prior to the outbreak of war. However,
the many uses to which it has been put have demonstrated that the panoramic idea,
particularly in the form of adaptors which may be connected to any receiver, is
going to be very important and useful in the ham station of the future. In simple
language this article reviews the general principles upon which the panoramic system
is based and includes also a picture of the many ways...
Federal Communications Commission will officially launch its
Space Bureau tomorrow, reflecting the agency's reorganization to deal with increased
interest in satellite-based communications. Chairwoman Jessica Rosenworcel proposed
the reorganization late last year and the Commission unanimously approved it in
January. The change splits the International Bureau into two 'separate, cooperative
units' within the FCC: The Space Bureau, which will focus on 'policy and licensing
matters related to satellite and space-based communications and activities,' and
Office of International Affairs (OIA), which will coordinate FCC work with foreign
and international regulatory authorities. The FCC has already received applications
for 64,000 new satellites, indicating just how much the sector is booming - particularly
in the area of low-Earth orbit (LEO) satellites. In the coming years, tighter integration
between 5G terrestrial and non-terrestrial networks is expected to emerge. Early
use cases for smartphone-based satellite connectivity are already in play, such
as T-Mobile US' deal with Starlink to share spectrum and provide ubiquitous text
message communications, expected by the end of this year, and Apple's emergency
SMS connectivity available in the iPhone 14 via service with GlobalStar's LEO network.
In January, Qualcomm also announced its Snapdragon Satellite, a 5G modem-RF system
which is designed to provide global..."
A schematic and parts list for the
Grantline models 605 and 606 tabletop AM radios appeared in a 1946 issue of
Radio News magazine. It is a 6-tuber with pushbutton tuning. Molded Bakelite
housings were popular in the day because complex curves with a smooth surface could
easily be accommodated, and usually a variety of colors were available. This white
one appears on YouTube. A few pages from the Sams Photofact data packet showed up
on eBay, so I did a screen capture of them for your convenience. 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. A running list of all
data sheets can be found...
It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
Wednesday the 19th
Having only been seriously (somewhat) on
the amateur radio scene since earning my Ham license in 2010, I previously did not
pay a lot of attention to antenna construction and interconnection to radio gear.
My experience was limited to routing 300 Ω twin-lead transmission line from
the rooftop TV antenna down to the indoor set. I also made a lame attempt at stringing
long AM antenna wire in an attempt to pull in distant stations at night. It
worked better than the built-in coil on the ferrite rod, but was nothing to brag
about. Evidently, there was a better method than a single lead for an AM antenna.
This 1969 Radio-Electronics magazine article suggests using a balun to
create a balanced twin line from the wire antenna to the receiver, then a balun
back to single line at the receiver end. Probably not many people are using such
configurations anymore, but the subject was considered worthy of a page in a national
publication in the day. Maybe there are still...
Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his April 2023 newsletter that features
his short op−ed entitled "Havana
Syndrome: Case Closed," which discusses where the U.S. government recently declared
their investigation into the mysterious neurological issues some foreign embassy
staff had been reporting showed that use of a microwave emitter to induce maladies
was "very unlikely." Keep in mind that conclusion was brought to you by the same
type government jackbooted thugs who brought you "safe and effective" vaccines.
Sam, as do I, believes just because government investigators have declared the "conspiracy
theories" to be unfounded, it does not remove the possibility of radiation poisoning
given the history of Communist regimes in not so long ago events. Russia and other
countries were caught zapping personnel with microwaves on multiple occasions. Sam
wrote about the Havana Syndrome back in 2019...
"One of the least known but most fascinating
of semiconductor devices is the
light-emitting diode (LED). Until quite recently, these devices were too expensive
for widespread use." That statement is hard to imagine in 2023. It was written 50
years ago by Mr. Forest Mims, in this November 1970 issue of Popular Electronics
magazine. Now, LEDs seem to be in every consumer device, whether it be a simple
power ON indicator light or an array of alpha-numeric displays. TV and stereo remotes
use infrared LEDs, opt isolators that use LEDs are integral components of modems,
motor controllers, and motion sensors. Commercial truck and some passenger vehicle
tail lights are made of LED clusters, as are the very expensive LED bulbs that are
quickly replacing incandescent and, thankfully, the toxic (mercury) CFL household
bulbs. What was once rare is now a commodity - it happens all the time...
of 5G/6G systems must take into account the seven major 'pillars' critical to
their successful creation, which center around antennas, receivers, and RF power,
among other key issues. In the Old Testament's Book of Proverbs, the first verse
of the ninth chapter is simultaneously enigmatic and captivating: 'Wisdom has built
her house; she has set up its seven pillars.' The verse has been referenced frequently
and in a broad variety of ways over the centuries. Regardless of how interpretations
of the verse may vary, all reflect an underlying understanding - that creative success
requires planning, expertise, insight, inspiration, using the proper instruments,
and above all, a commitment to achieve value that's both exceptional and unique.
We can logically extend the above to any endeavor in High Technology, and particularly
to one of the leading sectors for innovation at the chip, system, and software level:
RF communication systems in 5G/6G. At the heart of these communications systems
lies the physical layer, involving modulation, transmission, and demodulation of
signal and data content..."
When a worker assembling cellphones in a
plant in China hurls him/herself out of a window, it makes headlines. Like the human
cost of extracting the minerals that go into making cellphone components, people
yawn and write it off as the cost of progress. Among the many other dimensions of
that cost is one that, until recently, received little attention -
cell tower worker falls. According
to a joint investigation by Frontline and ProPublica that was aired in May 2012,
there is a well-established record of ill-equipped and ill-trained climbers who
fall [pun intended] victim to low budget operations... and, to be honest, sometimes
their own stupidity. Cell tower climbers experience 10x more on-the-job deaths as
the average construction worker. That might seem logical and even expected given
that you normally think of a construction worker as the guy banging nails in that
new housing development down the road...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies for
amplitude and phased matched VNA applications as well as standard & precision
RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the
iBwave component library. They also provide custom coax solutions for applications
where some standard just won't do. A partnership with Newark assures fast, reliable
access. Please visit ConductRF today to see how they can help your project!
Tuesday the 18th
You will probably breeze through both of
Your EQ?" circuit challenges in the February 1967 issue of Radio−Electronics
magazine. Don't look too deeply into what is presented. Both require figuring the
voltage between two points. For the Zener Limiting Circuit, just apply basic knowledge
about zener diodes. The "Voltage Problem" circuit requires a simple summing of voltages
around the single loop to derive the current, then calculate the voltage across
R1 to get VB. VA is a no-brainer. The depiction of the DC sources is a bit wonky;
the voltages shown are the totals for the each group of cells (aka battery), not
"Researchers at University of Tokyo, JTS
PRESTO, Ludwig Maximilians Universität and Kindai University recently demonstrated
the modulation of an electron source by applying laser light to a single fullerene
molecule. Their study, featured in Physical Review Letters, could pave the way for
the development of better performing computers and microscopic imaging devices.
'By irradiating a sharp metallic needle with femtosecond pulses, we had previously
optical control of electron emission sites on a scale of approximately 10 nm,'
Hirofumi Yanagisawa, one of the researchers who carried out the study, told Phys.org.
'The optical control was achieved using plasmonic effects, but it was technically
difficult to miniaturize such an electron source using the same principle. We were
seeking a way to miniaturize the electron source and we hit upon the idea of using
a single molecule and its molecular orbitals.' Yanagisawa and his colleagues set
out to realize their idea experimentally using electrons emitted from molecules
on a sharp metallic needle..."
Whenever you see an article with "The Truth
About..." in the title, the expectation is the author is going to reveal some aspect
about the subject that has been kept from public knowledge by nefarious schemers,
or a common misconception is going to be cleared up for the unwitting majority.
This 1952 QST magazine article comes closest to the later category, although
it is not really clear to me after reading it what the newly revealed "truth" is
- maybe just that the effort required for using a vertical antenna at fairly long
wavelengths is worth it because of low radiation angles that facilitate local area
and relatively nearby communications. A lot of really good information is presented
vertical antenna field patterns, antenna installation, and feedline systems...
This story on the SCMP website reports on
electromagnetic gun developed for riot control - which in China (and increasingly
in the U.S.) means any group opposed to a government policy. It is a mostly peaceful
gun in that it is purportedly designed to dissuade rather than injure or kill. Coin-shaped
projectiles are electromagnetically accelerated like a high velocity rail gun and
aircraft carrier catapult system. The quiet operation supposedly will invoke less
panic, which really means more people will stick around and get shot rather than
running away from the normal gunshot noise. If adopted in civilized Western countries,
a synthesized loud bang noise will be required by an attached speaker akin to how
electric cars are now being required to carry noise generators because they are
so quiet that pedestrians get run down in the cities. Governments are always
too smart by half.
Not having a full collection of magazines
is a real disadvantage when multiple part stories are published and some editions
are missing. Such is the case here with Milton Kiver's series on "Theory
and Application of UHF" in Radio News magazine. I do have other parts
of the series, but they have not been posted on RF Cafe yet. However, each
installment is pretty much independent of the others. This month's topic is on the
fundamental theory of electrical potential and force. The name "Maxwell" is mentioned,
but not in the way that strikes fear in the heart of engineering students being
introduced to the integral and differential forms of his eponymous equations (I
know first-hand), so it's safe to keep reading. Gauss's Law get honorable mention
as well. First semester physics books cover the same material, but since you might
not have one handy, here you go...
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...
Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments. 50 Ω and 75 Ω models are available, along with
a full line of precision calibration and connector adaptors.
Monday the 17th
Building speaker enclosures was a popular
project for stereo enthusiasts in the 1969 time period when this article appeared
in Radio−Electronics magazine. Lots of well-designed speakers were commercially
available, but they tended to be expensive. High−end speaker enclosures typically
had high−end speakers within, which contributed to the increased cost. I built a
pair of wooden enclosures while in the USAF at Robins AFB, Georgia. It had
a very nice woodshop. The speaker cabinets had a very simple internal design; the
removable front frame was the hardest part to build. Mine were made from pine. For
my level of music appreciation, I found that a quality set of car speakers provided
great sound for all but the deepest bass frequencies. An added advantage was that
the crossover circuit was built in, so all I needed was to build a crossover to
split the really low frequencies to 10" bass speakers that were purchased at Radio
Shack . The Radio Shack crossover circuits were too high (1 kHz) so I found
an article showing how to build one that split at around 500 Hz; admittedly,
it didn't work very well. The grille cloth also came from Radio Shack...
"Materials typically conduct electricity
or insulate against it - so experimental and theoretical physicists have been captivated
by a compound called samarium hexaboride (SmB6) that appears to do both. Numerous
studies over the course of 50 years have revealed that SmB6 acts like an insulator
as well as an electricity-conducting metal. Now, researchers from the Harvard John
A. Paulson School of Engineering and Applied Sciences (SEAS) say it's possible to
exact position of electrons along the surface of SmB6 with single-atom precision,
enabling a breakthrough in understanding the compound's properties and why it can
both insulate and conduct. The findings, published in Science, build upon SEAS research
reported in 2019 that determined that SmB6 is a topological insulator - meaning
it conducts electricity along its surfaces but not its insides. Despite the 2019
discovery about SmB6's surface metallicity, many questions remained about its overall
metallicity and why different measurements didn't generate consistent results..."
Mr. Lothar Stern, of Motorola Semi, published
a 3-part series on
transistor theory in Popular Electronics magazine in 1973. This is
part 1 (here is Part 2). By that time, transistors had pretty much replaced
vacuum tubes in all new electronic products - if you don't count cathode ray tubes
(CRTs) in televisions and some high power applications. Technical schools were still
teaching about vacuum tubes since there was a still a lot of legacy equipment that
needed to be maintained, and the main concentration had switched over to transistor
theory. 1973, the year I turned 15, is right around the time I began seriously delving
into the electrical and electronic realms as an eventual vocation. I distinctly
remember being bewildered and amazed the first time I was told, in a USAF classroom,
that a PN junction held to a fairly constant voltage (~0.7 V for silicon) regardless
of the current through it - within the specified operational range...
Werbel Microwave, a designer and manufacturer
of RF and microwave power couplers, dividers, terminations, and DAS equipment, introduces
the model C-9001-8.5, a
multi-output quad directional coupler that operates from 4 GHz to 18 GHz
with four separate output bands. This totally unique approach offers the ability
to filter different bands without the need of a power splitter, thereby reducing
the path insertion loss. The product is customizable in terms of dB value(s) and
multiplexed frequency bands. Werbel Microwave's catalog of directional couplers
and power splitters / combiners are high performance at an affordable price point.
Our original design, USA made...
"Don't forget who brung you to the dance,"
is a variation of the old adage that admonishes you to remember who/what it was
that provided the opportunity to be where you are now. It aptly applies to radio
communications of all sorts. This short article from a 1932 edition of Radio
News discusses the advent of radio beacon installations across America to facilitate
air navigation during inclement weather. Before there was a Federal Aviation Administration
(FAA), the Department of Commerce handled commercial air traffic for passenger and
cargo payloads. Aviation was on the verge of becoming a very profitable industry
(the Douglas DC-3 would make that happen in 1935) and it was necessary to develop
airspace controls to ensure safety and smooth operations. Early direction finding
equipment used a directional loop antenna to indicate the bearing (not necessarily
the heading, due to winds) to a ground-based broadcast station. Audible signals
indicated whether the aircraft location was to the left or right of the station.
Visual indicators would later provide course deviation information. Aside from GPS,
radio beacon navigation is fundamentally the same today as it was in 1932, only
with more precision, greater reliability, and more reference stations. If you don't
know a VORTAC station when you see it...
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 17,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners (hence "Triad") with
over 40 years of accumulated knowledge of what is required to design, manufacture,
market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA,
bi-directional, and frequency translating amplifiers are available, in formats including
tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology
partner than a vendor for our line-of-sight communications product line." Please
check to see how they can help your project.
Sunday the 16th
This custom RF Cafe
electronics-themed crossword puzzle for April 16th contains words and clues
which pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. As always, you will find no references to numbnut movie stars or fashion
designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page
links to hundreds of them dating back to the year 2000. Enjoy.
"SpaceX plans to carry out its first test
flight on Monday of
Starship, the most powerful rocket ever built, designed to send astronauts to
the Moon and eventually beyond. The launch is scheduled to take place at 7:00 am
(1200 GMT) from the sprawling Texas base of the private space company owned by billionaire
Elon Musk. Fallback times are scheduled later in the week if Monday's attempt is
postponed. The US space agency NASA has picked the Starship capsule to ferry its
astronauts to the Moon as part of the Artemis III mission, set for late 2025 at
the earliest. Starship consists of a reusable capsule that carries crew and cargo
and the first-stage Super Heavy booster rocket. The 164-foot (50-meter) tall Starship
spacecraft sits atop the 230-foot tall Super Heavy rocket. SpaceX conducted a successful
test-firing of the 33 Raptor engines on the first-stage booster of Starship in February..."
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
Providing full solution service is our motto,
not just selling goods. RF & Connector Technology has persistently pursued a management
policy stressing quality assurance system and technological advancement. From your
very first contact, you will be supported by competent RF specialists; all of them
have several years of field experience in this industry allowing them to suggest
a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable
assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically,
we put priority on process inspection at each step of workflow as well as during
final inspection in order to actualize "Zero Defects."
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
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