Here is the final installment in the "Basic
Digital Electronic Course" series that ran in three issues of Popular Electronics
magazine. The first two parts laid the groundwork with an introduction to binary,
octal, and hexadecimal arithmetic, Boolean logic, AND, OR and NOT gates, and some
truth tables. Armed with those fundamentals, the authors now dive into flip-flops,
encoders and decoders, debouncing circuits for switch inputs, integrated circuit
(IC) types, and interconnect methods to design and build a simple digital computer
with a 7-segment LED display. Don't expect too much from the computer since it was
only three years earlier, in 1971, that Intel introduced the world's first integrated
microprocessor - the 4-bit model 4004 central processing unit (CPU) ...
"It was made clear that I was not to touch
this sacred totem, especially the threaded rods..." - Steve Ford, WB8IMY, in an
article entitled, "Duplexers & Diplexers," in the October 2019 issue of
QST magazine. That statement was made in regard to a cavity-tuned duplexer
that was part of a Ham radio repeater installation. Mr. Ford, a monthly columnist,
discusses the difference between a duplexer and a diplexer. A pull quote from the
piece is, "If you're about to pay less than $100 for the device in question, it
is a diplexer. If the price tag has four digits to the left of the decimal, it is
a duplexer." Do you agree with that generalization? Unfortunately, the ARRL does
not make the magazine articles available to non-subscribers.
Planar Monolithic Industries (PMI) recently
introduced six new products in their extensive line of RF and microwave components.
Included are a successive detection log video amplifier (SDLVA) for 0.1 to 2.0 GHz;
a 18 GHz, 12-BIT, vector phase shifter; a digital frequency discriminator (DFD)
for 20 to 18.0 GHz, a 100 MHz amplified 8-way power divider, a 7-bit programmable
attenuator for 1.0 to 18.0 GHz, a 0.1 to 50.0 GHz SP16T absorptive switch, and a
Frequency Discriminator for 0.5 to 1.5 GHz. Contact PMI today for more information ...
As a long-time Paul Harvey fan, I used to
listen to his radio news broadcasts and especially looked forward to his "The Rest of the Story"
pieces. It was a challenge to listen and try to figure out who or what the alluded-to
person, place, or thing at the end of the the story would be. In honor of Mr. Harvey,
who left this Earth in 2009, the following Smorgasbord about featured celebrity
"Sam" is fashioned after his trademarked style. As is often the case with people
of accomplishment, this subject's talents extended beyond the skill for which he
is most known. An article in the September 2011 Smithsonian magazine inspired the
"A research team developed
VLF antennas using piezoelectric material and principles, resulting
in an antenna that's far smaller than metal antennas, thus overcoming a major impediment
to VLF links. While everyone is focused on RF signals in the gigahertz-plus range,
it's important to remember that the other end of the electromagnetic spectrum also
has its uses. However, signals in very-low-frequency (VLF) RF band present a technical
dilemma: On one hand, you can't easily live with them; on the other, you can't live
without them for some applications cases. The former assessment is due to their
need for extremely large antennas (on the order of kilometers). The latter assessment
is a result of their propagation characteristics, including Earth-hugging signals
and low atmospheric attenuation, as well as their ability to penetrate seawater ...
SF Circuits' specialty is in the complex,
advanced technology of
PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today.
On the heels of searching for the first mention
of Nikola Tesla in U.S. newspapers, I performed a similar search on
Albert Einstein, again using editions available in the NewspaperArchive.com
database. I was utterly surprised to find it in a 1919 issue of the The New York
Times. His theory of Special Relativity was published in 1905 and his theory of
General Relativity was published in 1915, so it took The NY Times four years to
mention it. There is a reference to Dr. Einstein's' work on relativity in a
1915 edition of The Manitoban*, from Winnipeg, Canada. The New York Times article
is an actual interview with Albert Einstein, wherein at one point it is stated that
there were perhaps only a dozen people in the world at that time who understood
general relativity. Interestingly, Einstein uses the term "difform motion" to describe
what we now call "non-uniform motion ..."
When I saw this photo of a man holding a
fluorescent light bulb in the beam of a radar antenna, it reminded me of how
we used to do the same thing on our AN/MPN-14 radar system in the USAF. The unit
in the photo is a General Electric's FPS-6 height-finding radar, which operates
in the S-band 2,700-2,900 MHz region. The AN/MPN-14 is a mobile ground control
approach (GCA) with both an S-band airport surveillance radar (ASR) and an X-band
precision approach radar (PAR). Our S-band radar had a 600 kW peak power whereas
the FPS-6 put out a couple megawatts, but 600 kW was enough to light the bulb.
Of course these days you would never see a company-sponsored photo of a man standing
in front of a high power radar antenna with a fluorescent light bulb in his hand ...
Here is a really interesting animation of
the world's top 20 country ranked by the
of Internet users in those countries. It runs (as of this posting date) from
1990 through 2019. I have not verified the numbers used by the Animate Stats producers,
but the results do not seem unreasonable. Given the the U.S. Department of Defense's
research arm, Defense Advanced Research Projects Agency (DARPA), created the Advanced
Research Projects Agency Network (ARPANET) that eventually became the Internet,
showing the U.S. as the run-away leader in the beginning is not surprising. Around
1996, things begin to change quickly as Japan advances, but it is in 2000 when the
Internet user landscape really becomes dynamic ...
Apologies to Chrysler aficionados for not
having similar articles for your classic automobiles, but this article from a 1957
edition of Radio & TV News only covers
Chevrolet radios. Maybe someday I will acquire editions with other models. Transistors
were fairly recent newcomers on the portable radio scene (on any radio scene for
that matter), so you will please excuse the absence of them in most radios of the
era. In fact, as evidenced by a companion article in this same edition titled "Delco's
All-Transistor Auto Radio," such newfangled devices like transistors were reserved
for top-of-the-line models like Cadillac's Eldorado Brougham. A move toward printed
circuit boards, rather than the time-honored point-to-point wiring, was well underway,
and push-button tuning was being sold to the car buying public as an indispensible
safety feature ...
Precision Ruggedized VNA Cables from ConductRF
offer RF Engineers great alternatives to costly OEM cables that are now past their
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50 GHz & 70 GHz. Our torque resistant connector heads and phase stable
constructions ensure great performance for many tests to come. ConductRF VNA series
provides customers with reliable ruggedized solutions for Lab and Production Vector
Network Analyzer testing. With options for 18 GHz, 26.5 GHz, & 40 GHz,
these cables offer cost leading alternatives to original OEM VNA cable solutions.
VNA Series cables are enhanced with a stainless steel spiral armor ...
"To hear technologists describe it,
Wi-Fi 6 is about to transform connectivity. The next-generation
Wi-Fi connectivity technology - along with the emerging 5G cellular generation -
will shake up the way we connect with each other. The ability of Wi-Fi 6, or 802.11ax,
to instantly route traffic - even to devices on the far reaches of very crowded
networks - will also change the way we interact with our smart devices. It will
even rework the way smart devices communicate with each other. But from what we've
seen thus far, Wi-Fi 6 is emerging on the scene in much the same manner as previous
generations of wireless technology: integrated inside the latest smartphones and
laptops. And in new routers and access points that promise faster ..."
Alliance Test sells
refurbished test equipment and offers short- and long-term rentals. They also
offer repair, maintenance and calibration. Prices discounted up to 80% off list
price. Agilent/HP, Tektronix, Anritsu, Fluke, R&S and other major brands. A
global organization with ability to source hard to find equipment through our network
of suppliers. Please visit Allied Test Equipment today to see how they can help
On a whim, I did a search for the earliest
appearance of Nikola Tesla's name in U.S. newspapers included in the NewspaperArchive.com
database. This story from Mr. George Grantham Bain appeared in multiple newspapers
within a few days of this March 5, 1896 edition of The Warren Times in
Warren, Pennsylvania, which coincidentally is only a few miles from me here in Erie.
The article reports on the role that Tesla's high voltage generators played in the
development of x-ray images on fluorescent displays and on film (which Tesla termed
"cathode photography"). It mentions how the term "cathode" is relatively new to
the general public even though it had been around since 1832 when Michael Faraday
introduced it in his work. Wilhelm Röentgen made the world's first x-ray image ...
1957 was part of the heyday of the newfound
radio-in-your-car craze, and the public was voraciously consuming all the high
tech equipment it could afford. Rock and Roll music was on every teenager's mind
and many guys for the first time were able to have their own wheels and were outfitting
them with sound systems that could blast the latest works of Buddy Holley, Chuck
Berry, Elvis Presley, and Fats Domino. Those machines were the first babe magnets
used for cruising the strip on Saturday nights. Radio stations were popping up all
over the country, enabling cross-country travel with non-stop music, news, and variety
show entertainment. Ford and Chevrolet were not going to miss an opportunity, so
they delved into the high end mobile radio manufacturing business ...
QuinStar Technology designs and manufactures
mm-wave products for communication, scientific, and test applications
along with providing microelectronic assembly, rapid prototyping, and mass customization.
Amplifiers, Oscillators, Switches, Attenuators, Circulators, Isolators, Filters,
Waveguide, Antennas, Phase Shifters, Transceivers, Mixers, Detectors. QuinStar specializes
in cryogenic amplifiers, circulators, and isolators. Please
visit QuinStar today to see how they can help your project.
It took me a couple passes of the explanation
to comprehend the advantage of a Thomson-Varley (aka Kelvin-Varley, since Thomson
and Lord Kelvin are one and the same person)
switchable voltage divider compared to a standard type. At first I thought the
author, Edwin Bohr, was implying that the source and load impedances would not have
as great of an effect on the accuracy of the divider (and to some extent it is less
sensitive), but the main advantage is that the configuration permits simple cascading
stages of decade dividers to achieve essentially any degree of resolution. Both
a standard series-wired type voltage divider and the Thomson-Varley need ten resistors ...
Ruh-roh. "Switzerland was among the first
countries to begin deploying 5G, but
health fears over radiation from the antennas that carry the
next-generation mobile technology have sparked a nationwide revolt. Demonstrators
against the technology are due to fill the streets of Bern later this month, but
already a number of cantons have been pressured to put planned constructions of
5G-compatible antennae on ice. The technology has been swept up in the deepening
trade war between China and the United States, which has tried to rein in Chinese
giant Huawei - the world's leader in superfast 5G equipment - over fears it will
allow Beijing to spy on communications from countries that use its products and
At VidaRF, the phrase 'Providing Simple
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and distribute high performance, cost effective
RF Microwave products to fit each customer's unique applications.
Please visit VidaRF today to see how their lines of attenuators & terminations,
directional couplers, power dividers, coaxial connectors, and circulator & isolators
can be of use to your project. "When the standard just will not do, VidaRF has the
solution for you!"
English mathematician George Boole published
Logic" syllogism system of deductive reasoning in 1847. Fellow countryman Augustus
De Morgan followed on Boole's work to develop the basic combinational logic rules
the AND gates, OR gates, and NOT (negation) operators. What has become known as
Boolean algebra and De Morgan's theorem forms the fundamental foundation of everything
related to digital logic. This second in a three-part series from a 1974 issue of
Popular Electronics introduces both concepts at a beginner's level. Part 3 will
present flip-flops and an overview of how all the parts come together to build a
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 at no charge (of course
a gratuity will be graciously accepted). 3rd party recruiters and temp agencies
are not included so as to assure a high quality of listings. Please read through
the easy procedure to benefit from RF Cafe's high quality visitors ...
Linx Technologies, a Merlin, OR based developer
and manufacturer of antennas, is pleased to introduce the
Splatch® SP610 antennas. The Splatch® SP610 is a surface mount monopole antenna
for embedded LTE and cellular IoT (LTE-M and NB-IoT) applications. It specifically
supports low-frequency LTE bands from 698 MHz to 960 MHz, notably the
700 MHz bands, and 1710 MHz to 2700 MHz making it an outstanding
antenna for LTE and cellular low power wide-area (LPWA) applications in North America,
Europe and worldwide. The SP610 uses a grounded-line technique to achieve outstanding
performance when subject to nearby sources of interference ...
Sam Benzacar of Anatech Electronics, an RF
and microwave filter company, has published his September newsletter that features
his short op−ed entitled "Interference:
5G Hits a Snag." He mentions the unavoidable issues that are being faced by
telcos trying to deploy their 5G infrastructure that operates in the millimeter-wave
bands. The two most notable difficulties are that of expensive equipment costs and
relatively short propagation distances (per Mr. Friis' equation). It is the
latter that is partly responsible for the former difficulty because shorter ranges
translate to needing more closely spaced cells. Re-allocation of some existing bands
is inevitable, which worries Hams more than just a little since their spectrum privileges
seem to uninformed bureaucrats to be ...
Here is a
recruitment advertisement published by the the U. S. Army in the July 1959 edition
of Popular Electronics. This was only a few years after the Korean War
ended in 1953 and a couple years before we got involved in the Vietnam War in 1961.
It's always interesting to see what the mindset about the current state of electronics
was many moons ago, and to compare it with today's technology. In the same manner,
people 60 years from now will look at today's recruitment ads and be amazed at how
relatively crude our contemporary state of the art is.
"There are numerous causes for projects to
break down. Five of the common causes include never-ending debugging cycles, stop-and-go
projects, projects that are more difficult than anticipated, projects that go past
deadline, and projects that force overtime.
Project fatigue can have a crippling effect on the project development
cycle. A project starts and the development team is energized and dive in with positive
fervor, but before long, the project stalls and seems to be going nowhere fast.
There are dozens of potential causes for project fatigue, but in my experience,
there are five main causes that result in project fatigue for developers. Let's
examine these causes. "
Superstore launched in 2017, marking the return of Murray Pasternack, founder
of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally
changed the way RF components were sold. Partner Jason Wright manages day-to-day
operations, while working closely with Mr. Pasternack to develop RF Superstore into
a world class RF and microwave component supplier. RF coaxial connectors & adapters,
coaxial cable & cable assemblies, surge protectors, attenuators. Items added
daily. Free shipping on orders over $99. We're leading the way again!
This first of a three-part series on
digital electronics run by Popular Electronics magazine begins with
introducing binary (base 2), octal (base 8), and decimal (base 10) number systems,
along with conversions between the types. Sure, this is probably old-hat to most
RF Cafe visitors, but there is always a new cadre of electronics enthusiasts entering
the field who appreciate the instruction. No matter how advanced digital electronics
gets, a fundamental understanding and fluency in binary arithmetic is essential
to success whether as a hobbyists or as a professional. If you cannot move effortlessly
between the various number formats (which also include hexadecimal and Gray code),
then continuing to Boolean algebra ...
When semiconductor devices first came onto
the electronics scene, there was a lot of resistance (pun intended) to adopting
and designing them into circuits. Some of the reluctance (doh, another intentional
pun) was justified in that reliability could be an issue, due primarily to the mechanical
contacts that interface wire leads to the semiconductor elements. In an effort to
mitigate some of the fear of a new type of component, often times familiar names
were given to them, such as with this
Duo-diode vacuum tubes, the integration of two separate diodes into a single glass
enclosure, were commonly used in balanced signal detectors because it was a way
to achieve nearly exact performance in the pair that would track equally even as
the tube ...
Keysight Technologies just announced the
availability of of a new, free webinar entitled, "Overcome the Challenges of mmWave." "The move to millimeter-wave
doesn't come easily. There are new techniques required, and with these new techniques
come a number of testing challenges you've likely never encountered. Are you ready?
In this pre-recorded webcast, Pete Cain, Wireless Solutions Planner at Keysight
Technologies, one of the foremost experts in this field, walks you through the challenges
of millimeter-wave. Get an overview of the applications, and the spectrum and device
under test before moving into a variety of measurement related issues."
You know you're old when a 1992 car radio
does not seem like it should qualify as a vintage electronics. Electronic Design's
Paul Rako has posted his findings when investigation a failed
AM/FM radio from his 1992 Honda car. "The radio in my 1992 Honda
started acting up a decade ago. The display went out first. Pressing or hitting
the front panel brought it back, at least for a while. Then the tuner was intermittent,
no matter if the display was working. Four years ago, the radio really broke. It
would not play at all; worse yet, there would be loud RF squealing in the speakers,
even with the radio turned off. I assumed this was from a blown output section that
was receiving electromagnetic interference (EMI), which the blown transistors would
rectify and detect ..."
Reactel has become one of the industry leaders
in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. Through
a continuous process of research and development, they have established a full line
of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more.
They offer the generally known tubular, LC, cavity, and waveguide designs, as well
as state of the art high performance suspended substrate models. Established in
1979. Please contact Reactel today to see how they might help your project.
RF Cafe Engineering & Technical Headlines Crossword Puzzle contains at least
10 words from headlines posted on the homepage during the week of September 9 through
September 13, 2019 (marked with an asterisk*). These custom-made engineering and
science-themed crossword puzzles are done weekly for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. Every word and
clue - without exception - in these RF Cafe puzzles has been personally entered
into a very large database that encompasses engineering, science, physical, astronomy,
mathematics, chemistry, etc. Let me know if you would like a custom crossword puzzle
built for your company, school, club, etc. (no charge).