In this Radio & Television News
magazine article, author Jack Gallagher derives a formula for the number of turns
of wire to wind on a form of given dimensions for a parallel
constant-resistance network. He argues that although commonly used formulas
like that of Wheeler provide the number of turns needed to achieve a desired value
of inductance, it does not predict the size of cross-sectional shape of a coil form
that results in an optimal configuration. His work applies to audio frequency divider
networks like those used for speakers to steer specific frequency ranges to a woofer,
midrange, and tweeter trio; hence the need for "constant resistance" (e.g., for
standard 8 Ω or 16 Ω speakers). By the way, in case you are not
familiar with the annotation in older electronics articles, "mhy" is microhenries,
and "s.c.c." is...
was neither particle nor wave, but a bit of both - a wavicle." - Ian Stewart, in
Pursuit of the Unknown: 17 Equations That Changed the World," 2012, regarding
the dual nature of light as covered in the chapter on
for wave functions. BTW, the real term used is "wave–particle duality,"
which is a quantum mechanical principle stating that all matter–energy has both
a wave and a particle nature. The wave behavior of light is exhibited in its ability
to be diffracted at a sharp edge. It is the particle nature which accounts for the
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio 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...
"A database of
drone radar cross sections has been made public to help those developing countermeasures.
'We measured drone radar cross sections at multiple 26-40 GHz mm−wave frequencies
to better understand how drones can be detected, and to investigate the difference
between drone models and materials in terms of scattering radio signals,' said researcher
Vasilii Semkin of VTT Technical Research Centre of Finland. 'We believe that our
results will be a starting point for a future uniform drone database. Therefore,
all results are publicly available along with our research paper..."
Ok, the real title on the Interesting Engineering
website is, "11
Ways Engineers Are Helping out to Fight Against the Pandemic." Individuals and
companies (comprised of individuals) are responding to the COVID-19 crisis in an
utterly amazing manner. Except for grandstanding politicians and agenda-driven,
hateful media types, many of our fellow Earthlings are working tirelessly to provide
a way out of this present surreal crisis, and in the process are developing new
knowledge and technology that will benefit us during "the next big thing." Others
do what they can do by honoring precautionary rules of sanitation and separation.
Admittedly, the exercising of extreme governmental powers worries me a bit as limits
of citizens' willingness to comply are tested. One American politician famously
recommended, "You never let a serious crisis go to waste. And what I mean by that
it's an opportunity to do things you think you could not do before." Here is the
original 1974 "Everybody Was
Kung Fu Fighting" song (I was in 10th grade). Be careful.
In an effort to promote entry of women and
girls into the amateur radio hobby, Short Wave Craft magazine ran a few
Best "YL" Photos. Amazingly - and maybe there are still instances of it today
- many (if not most) of the YLs featured had built their own equipment. In 1935,
most people built their own equipment, so that is not too surprising. The winner
for this month was a 16-year-old young lady (i.e., "YL") who in fact built her rig.
Another winner was an 83-year-old grandma who was born before Marconi, Maxwell,
and Hertz did their best work! The third winner was a girl who earned her Ham license
at age 6, which back in the day required sending and receiving 5 words per minute
(WPM) in Morse code. BTW, according to the Bureau of Labor Statistics' (BLS) Inflation
Calculator says $5 in 1935 is the equivalent of $94.41 in 2020 money...
Anatech Electronics (AEI) manufactures and supplies
RF and microwave filters
for military and commercial communication systems, providing standard LP, HP, BP,
BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter
and cable assembly products are published in our website database for ease of procurement.
Custom RF filters designs are used when a standard cannot be found, or the requirements
dictate a custom approach for your military and commercial communications needs.
Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please
visit Anatech today to see how they can help your project succeed.
Multiple path transmission, diffraction around
obstacles, absorption by foliage, and reflection from moving objects have always
been challenges to the wireless system designer and/or user. Whether it concerns
communications between a WiFi router and a notebook computer, a cellphone and a
tower, an FM radio with a broadcast station, or deep space probe with an earth station,
all of the aforementioned mechanisms must be dealt with to some degree. Although
in a different way, even
transmissions within a waveguide or coaxial cable deal with those same issues
- reflections and the resulting standing waves have the same effect as multipath
in terms of vectorially additive versions of the same original signal. Signal degradation
issues can usually be overcome when all components are performing within specifications,
by having knowledge potential causes, and then assessing the situation at hand.
Of course an insufficient signal power from the transmitter, too-high Friis-determined
atmospheric path loss, and inadequate receiver sensitivity under ideal conditions...
ConductRF LSA series of Low Loss, Performance
RF cable assemblies, provide microwave system designers with a versatile solution
for most applications. Here we offer customers a solution for 0.086" diameter cable
that facilitates greater flexibility and handling or, 0.141" diameter that exploits
the same great performance but with almost half the loss. Connector options include
SMA, Type-N, TNC & SMP that provide excellent VSWR between DC and 18 GHz,
also solutions for MCX & SMB are available in a wide array of configurations.
These assemblies are built using our own double shielded, FEP jacketed cable, that
was developed specifically for performance solutions. With shielding effectiveness
exceeding 90 dB through 18 GHz, these cables minimize the threat of cross-talk
effect. ConductRF guarantees its performance through 100% factory test prior to
shipping. Additional options are also available...
Triad RF Systems' Steve Barthelmes, Patrick
Sherlock, and Ken Andrew published a Technical Brief article entitled, "Methods
to Increase Channel Capacity in RF Data Links," in Microwave Product Digest.
"As can be seen, increasing the robustness of RF links is a tricky business, however,
there are multiple weapons in one's toolkit to increase capacity and combat RFI.
MIMO is a radio technology that is taking hold worldwide. This wireless technology
increases the channel capacity of the system while improving the reliability of
the link. High gain antennas and tracking technologies can be employed, however,
the mobile aspects of many RF links (UxV systems) do not always allow for the size,
complexity, and sensitivity trade-offs that come along with them. BDAs can be employed,
in conjunction with these other technologies, or alone, to increase the link margin
of systems that are underperforming, however, there is a modest cost and power trade-off..."
Do you know how engineering whipping boy
Dilbert came to be called
by that name? Per Scott Adams, while working at Pacific Bell he ran an informal
name-the-comic-strip-engineer contest from his cubicle. A guy named Mike Goodwin
suggested Dilbert. "I ended the contest immediately and declared Mike the winner,"
says Adams. It sounded perfect. Years after the comic strip had become syndicated,
Mike commented that he believes the name idea might have come from seeing his father's
old WWII aviator comics with "Dilbert the Pilot." DtP was a screw-up, invented by
Navy artist Robert Osborn, whose purpose in life was to illustrate the wrong way
of doing things so that real pilots wouldn't make the same mistakes. The name was
funny then, as it is funny now. BTW, Dilbert is a variant of Delbert meaning nobly
famous. During the War, "dilbert" became a synonym for "blunder" for Navy pilots.
The Navy even produced an aviator safety film titled, "Don't Kill Your Friends,"
featuring Dilbert the Pilot...
"Verizon, along with Samsung Electronics
Americas, Motorola Mobility, and Qualcomm Technologies, have teamed up to demonstrate
5G peak speeds of
4.2 Gbps on a live 5G network. Using carrier aggregation, a technology that
combines multiple channels of spectrum to provide greater efficiency for data sessions
transmitting over the wireless network, the four companies combined eight separate
channels of mmWave spectrum to achieve the multi-gigabit speeds on Motorola's upcoming
flagship smartphone. Adam Koeppe, Senior Vice President of Technology Planning at
Verizon commented that they are continuing to expand the 5G Ultra Wideband network,
built to enable unique and transformational experiences for their customers. They
continue to innovate and introduce advanced technologies on their 5G network that
will help them reach 'never seen before' mobile capabilities..."
Res-Net Microwave has a complete line of precision
RF & microwave components
including attenuators, terminations, resistors, and diode detectors for commercial,
military, and space applications. Products range from the small flange type to large
2,000 watt connectorized power attenuators and/or terminations at frequencies up
to 26.5 GHz. In-house photo etch and laser trim capability. The company is
a leader in development and production of the films required for these type of RF/microwave
components. Please check out Res-Net Microwave's website to see how they can help
with your current project.
Those of us who have been around for six
or more decades have lived through two evolutions of video display types - raster
cathode ray tubes (CRTs) and digitally pixelated light-emitting diode (LED)
and liquid crystal (LCD) displays. Unlike with the latter display types that improved
in color depth, picture resolution and display size, the former had effectively
a fixed resolution of horizontal lines (525 vertical steps - only 484 visible, actually,
due to blanking). That meant for CRTs, designers needed to find ways to make images
appear in-focus while also looking continuous on larger screens. Doing so involved
cleverly adjusting the size and spacing of fluorescent color dots on the picture
tube face while also using special metal masks between the electron gun and the
tube. A lot of research that included panels of people rendering opinions...
Watched These Movies and TV Shows as a Kid. The Design News website
likes to run these "You Know You're an Engineer If..." things, and usually they're
pretty good. This one, of course, has me waxing nostalgic. "Here are some of classic
engineering and robot movies and TV shows from the 1950s and 1960s. Every kid who
grew up to be an engineer loved robots. The love of science fiction and robots seems
to follow closely on the heels of the fascination with dinosaurs. Some of these
movies were scary for a kid, like the deadly robot in The Day the Earth Stood Still.
Others were lovable, like Robbie the Robot in Forbidden Planet. Some were terrifying
in a more realistic way, such as HAL in 2001 a Space Odyssey..."
Each year the Foundational Questions Institute
(FQXi) holds an essay contest inviting writers to submit missives addressing the
question chosen by the FQXi board as being particularly thought-provoking. In their
words, "FQXi catalyzes, supports, and disseminates research on questions at the
foundations of physics and cosmology, particularly new frontiers and innovative
ideas integral to a deep understanding of reality, but unlikely to be supported
by conventional funding sources." The 2011 question was "Is Reality Digital
or Analog?" Scientific American magazine, being one of three partners,
published the runner-up entry in the December 2012 issue: University of Cambridge
professor of theoretical physics professor David Tong's paper argues that the world
is in fact fundamentally analog. Professor Tong actually tied for second place,
but for some reason SciAm does not tell us whether the other second place paper
supported an analog or digital viewpoint...
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
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...
"Provider of integrated solutions for transportation
and defense C4ISR, Cubic Corporation has announced that their Cubic Mission Solutions
(CMS) business division has been selected as one of the awardees to compete under
the U.S. Army for
Global Tactical Advanced Communication Systems (GTACS II) Indefinite Delivery/Indefinite
Quantity (IDIQ) contract vehicle. The contract has a ceiling of $5.1 billion, with
a five-year base, one five-year option period and a Firm Fixed Price, Cost Plus
Fixed Fee and Cost No Fee contract, in support of the Program Executive Office Command,
Control and Communications-Tactical (PEO C3T), and Project Manager Tactical Network
(PM Tactical Network)..."
Axiom Test Equipment allows you to
test equipment, repair
test equipment, or
sell or trade test equipment. They are committed to providing superior customer
service and high quality electronic test equipment. Axiom offers customers several
practical, efficient, and cost effective solutions for their projects' TE needs
and is committed to providing superior customer service and high quality electronic
test equipment. For anyone seeking a way to offload surplus or obsolete 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!
Other than vaguely recognizing the name,
do Millennials know who
Mickey Mantel was? Maybe hard-core Yankees fans of all ages still know. My having
been born in 1958, the kids in my neighborhood watched "The Mick" playing on TV,
witnessing real-time some of his final 536 career home runs being hit. When this
two-page Westinghouse advertisement appeared in a 1954 issue of Radio & Television
News magazine, he was only beginning in his forth season in Major League Baseball
(MLB), which ran through 1968. The promotion was for a contest where servicemen
who bought Westinghouse vacuum tubes submitted a witty response for the comic showing
a housewife (that's what we called them back then) asked the poor bloke who fixed
her TV set, "All that money to replace this little tube?" It was a line heard day
in and day out...
Just as in the Gulf War air superiority
was credited for minimizing damage to bodies and structures on the ground, so will
space superiority be essential to surviving global threats on the ground. A strategically
sufficient space system of communications and retaliatory weapons will be key to
maintaining peace (at least physically if not financially). Gen. Steven Kwast, USAF,
ret., has an opinion piece posted on the High Frequency Electronics website
Urgent Need for a U.S. Space Force," with useful professional insight. "The
following is adapted from a speech delivered on November 20, 2019, at Hillsdale
College's Allan P. Kirby, Jr. Center for Constitutional Studies and Citizenship
in Washington, D.C., as part of the AWC Family Foundation lecture series. In June
2018, President Trump directed the Department of Defense to 'begin the process necessary
to establish a space force as the sixth branch of the armed forces..."
The Klondike / Yukon Gold Rush is generally
credited with opening up the Alaskan territory to exploration and habitation. Gold
was first reported in August of 1896, just three decades prior to this advertisement
in a 1931 issue of QST magazine by the
De Forest Radio Company extolling its domination of the region with radio
communications stations. Company founder Lee De Forest was very successful
in exploiting the virtues of his famous Audion amplifier tube. A back-handed swipe
is taken at Government installations that used "whatever tubes the Government has..."
"The Defense Department's networks have seen
an uptick in cyberattacks this past week, and officials want to restrict the use
of commercial streaming services, such as YouTube, as much of its workforce goes
remote in response to the coronavirus pandemic. The U.S. is grappling with the
COVID-19 pandemic with many companies and government agencies calling for telework.
But it's a twofold challenge for DOD, which has 37 reported cases, as it tries to
meet device demands and keep down network vulnerabilities. Essye Miller, the principal
deputy CIO for DOD, said the organization's networks experienced a surge in cyberattacks
as more employees were pushed to work remotely if possible..."
rfLyncs proprietor and chief engineer Steve
Ledingham contacted me about listing his company's services on the RF Cafe applicable
Antenna Vendor pages (Technical Services,
He specialized in RF hardware, wireless systems and antenna design for over 20 years
in commercial, medical, military and aerospace industries. rfLyncs provides
custom antenna design, on-site antenna testing,
wireless and RF design consultancy services for IOT and M2M devices. Experts in
GPS, WiFi cellular, LTE connected devices. We help you meet or exceed your user
requirements in a cost effective way by providing custom antenna design, antenna
selection and integration, antenna test services, and RF & wireless hardware
design. rfLyncs is located in Greater Boston area of Massachusetts. Please check
out rfLyncs to see how Steve's expertise might
help your project.
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 RF today.
As with many relatively new technologies,
exuberance over radio peaked quickly once the benefits of communications over
long distances without the need for wires was realized by the public. After a couple
decades a lot of "authorities" began pontificating about how all the useful applications
of radio waves had been discovered and that any new innovation would be merely incremental
improvements in existing technology. Novel circuits for minimizing static over the
radio or maybe building more powerful transmitters for longer range were the only
concepts within reach of their limited imaginations. Similar phenomena occurred
for those who thought airplanes would always have two (or more) wings and that automobiles
would never be faster than a train. This 1935 issue of Short Wave Craft
magazine reported on the beginnings of investigations into the use of radio waves
RF Cascade Workbook 2018 is the next phase in the evolution
of RF Cafe's long-running series, RF Cascade Workbook. 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...
smart grid that has online components will mean opening up the network to potential
cyberattacks. But the risk may be warranted to see the electrical grid and its related
systems brought into the modern age. It's rather evident that collectively, the
energy industry must make some optimizations to the conventional power grid. There
are many questions and concerns - both ethical and security-focused - about implementing
smart and IoT-related technologies. Implementing a smart grid with online components
will mean opening up the network to potential cyberattacks. That said, the risk
may be worth it to see the electrical grid and its related systems brought into
the modern age. The particulars are still being worked out, at least on a grand
is ground the world around." That's a saying that I have often heard Ham radio
operators say aloud and in writing. In a general sense, it's true, but on a local
level grounds can vary widely from location to location, even within a few hundred
feet. It is true both for direct current and low frequencies and for frequencies
in to the GHz regions. It has to do with the conductivity of the soil and/or rock
in the area as well as the amount of moisture and other elements in the ground.
Antenna guys like to run conductive (usually copper) "radials" out from the mounting
pole or tower in order to create a sufficient local reference ground, and electric
power distribution engineers often need to salt the ground around substations with
ionic compounds in order to create sufficient conductivity to provide a safe grounding
This article on the Microwaves & RF
website entitled, "Algorithms
to Antenna: Modeling Antennas Installed in the Presence of Large Platforms,"
deals with large conductive solid surfaces and meshes (e.g., towers and steel beam
buildings) in the near field. Even with today's powerful PC platforms, solving the
huge matrices involved in method of moments (MoM) simulations can take a significant
amount of time. That's not so bad once an accurate model has been confirmed, but
during the "guesstimate" stage running validation simulations can suck up a lot
of time. "To consider the effects of an electrically large platform, a physical-optics
(PO) solver helps provide you with a good result without a large increase in simulation
time." Sure, it's an infomercial for Mathworks, but then a large portion of these
magazine articles are, and they are extremely valuable.
Since 1961, MECA
Electronics has designed and manufactured an extensive line of
RF & microwave components
for in-building, satellite, radar, radio, telemetry, mobile radio, aviation &
ATC. Attenuators, directional & hybrid couplers, isolators & circulators,
power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables.
MECA has long been the 'backbone' of high performance wired and air-interfaced networks
such as in-building applications, satellite communications, radar, radio communications,
telemetry applications, mobile radio, aviation & air traffic communications.
was a Tweet put out by the World Health Organization on January
14, 2020: "Preliminary investigations conducted
Chinese authorities have found no clear evidence of human-to-human transmission
of the novel coronavirus (2019-nCoV) identified in Wuhan China."
Since Twitter posts have a way of disappearing when proven embarrassing, that hyperlink
goes to an archived Google page. For some reason Archive.org is not able to save
Twitter pages (I tried to force a save, but it failed). President Trump initiated
travel ban on January 31, 2020 (and caught heck for it), two weeks prior to
WHO's infamous Tweet telling the world not to worry.
This March 22, 2020,
tech-themed crossword puzzle contains only clues and terms associated with engineering,
science, physical, astronomy, mathematics, chemistry, etc., which I have personally
built over nearly two decades. Many new words and company names have been added
that had not even been created when I started in the year 2002. You will never find
a word taxing your knowledge of a numbnut soap opera star or the name of some obscure
village in the Andes mountains. You might, however, encounter the name of a movie
star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons
which, if you don't already know, might surprise you...