See Page 1 |
2 |
3 |
4 | of the April 2020 homepage archives.
 This Bell Telephone Laboratories (aka Bell
Labs) advertisement appearing on the inside back cover of the 1958 issue of
Radio & TV News magazine celebrated the 10th anniversary of their
announcement of the world's first
point contact transfer resistance (transresistance) semiconductor
device - aka the transistor. John Bardeen, William Shockley and Walter Brattain
recorded the monumental event in a lab notebook on December 23, 1947 - a nice Christmas
present for the world! The trio's invention was not like the robust bipolar transistors
used today, or even ten years later in 1958. Rather than employing point-contact
"cat's whisker" metallic probes for making the emitter and collector contacts with
the germanium PN base substrate, commercially viable bipolar transistors use a doping
element diffused into the purified crystal substrate to effect the emitter, base,
and collector regions on a single crystal (with gold contact pads for attaching
external leads)...
 "NASA has selected a mission to dispatch
six
CubeSats, each the size of a toaster oven, to an orbit more than
20,000 miles from Earth to study massive particle ejections from the sun. The Sun
Radio Interferometer Space Experiment, or SunRISE, mission will launch no later
than July 1, 2023, after its selection by NASA as a mission of opportunity under
the agency's Explorers program. SunRISE will consist of six CubeSats flying as close
as 6 miles (10 kilometers) from each other. The nanosatellites will together act
as a giant radio telescope, detecting low-frequency emissions from solar activity
and downlinking the measurements through NASA's Deep Space Network. Data gathered
by the SunRISE CubeSats will tell scientists about the source of coronal mass ejections,
which launch huge bubbles of gas and magnetic fields from the sun. Employing a constellation
of small satellites will allow researchers..."
 Popular comic strips (aka 'funnies') in
the 1930s and 1940s featured numbskulls, ne'er-do-wells, and simpletons. There was
usually one character in the strip's cast that was smart - at least in a relative
way if not absolute. Being familiar with some of the old comics like Blondie, Barney
Google, Krazy Kat, Beetle Bailey, Gasoline Alley, etc., I can see a definite relationship
between the story line of "Entertaining Uncle Oscar" and the comics of the era in this short
story that appeared in a 1939 edition of the ARRL's QST magazine. As you
might guess, the feller named 'Ham' is the smart one. Q: Is it irony, coincidence,
or premonition on the author's part that the uncle's name is the same as the ARRL's
OSCAR series of Orbiting Satellite Carrying Amateur Radio(s)?
"Empower-RF-Systems-Solid-State-GaN-SiC-Amplifier-10-kW-Peak-Pulsed-Power-4-15-2020.htm"
Empower RF Systems "Empower-RF-Systems-Solid-State-GaN-SiC-Amplifier-10-kW-Peak-Pulsed-Power-4-15-2020.htm"
Model 2213 is a compact solid state GaN-on-SiC amplifier delivering 10 kW of
peak pulsed power. This air cooled 10 kW, 6% duty cycle pulse amplifier system
brings sophisticated monitoring, protection, and control functions to mission critical
applications. It's an intelligent amplifier system with a flexible software and
embedded firmware design that can be customized to add mission support capabilities
specific to the users integrated system. Remote control and monitoring is included.
The 2213 is based on Empower's established and field proven Next Generation architecture
that is tactically deployed and operating on multiple levels in support of a variety
of critical DOD missions...
 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...
RF Superstore launchedin 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!
 Plastic is one of those materials that seems
like it has been around since the dawn of time - like metal. There was an Iron Age
in the 1,000 BC timeframe (depends on location), but the Plastic Age - not
that there officially was one - did not begin in the commercial world until World
War II. If you note in older photos and films, there was not much, if any,
in the way of objects made of
plastic before the 1940s. In fact, the formulation and production
of some types of plastic like Plexiglas and polycarbonates was considered a matter
of national security for a while both for Allied and Axis powers. Bomber and fighter
aircraft windshields were made of the material. After the war, use of plastics for
industrial and consumer products exploded due to the much easier manufacturing of
product enclosures, knobs, and parts with complex shapes. Lighter weight, lower
cost, easy application of color, and in some cases greater robustness made plastic
very popular with consumers. Plastic does have its drawbacks compared to the wood,
metal, and phenolic materials previously used for radios, TVs, and phonographs,
and Barney experienced one of them...
 Messrs. Krunal Maniar and Ryan Andrews have
published an article on the EDN website entitled, "Mitigate Clock Intermodulation Effects in Characterization Setups."
Intermods have been an issue since the beginning of electronic - even before digital
circuits. It begins: "Mixed-signal PCBs present unique challenges in high-performance
applications, such as vibration analysis and other multi-channel data acquisition
systems. Nonlinear signal-chain elements introduce unwanted harmonic distortion,
increasing the magnitude of the input signal's harmonic content. Meanwhile, multiple
switching elements produce intermodulation artifacts that present themselves as
frequency spurs asynchronous to the signals of interest. The noise and distortion
degradation introduced by these nonidealities can significantly limit the overall
performance of applications aiming for high resolution at high bandwidth. In this
article, we'll explain how clocks and other switching elements produce intermodulation
artifacts..."
 When really good researchers set out to
write books on history, they do not simply cull information from the publications
of fellow contemporary authors; instead, they look for sources that were published
during or around the time of the subject being covered. Doing so helps minimize
the possibility that inaccuracies have crept into the knowledge pool and that information
other authors might have either deemed insignificant or have missed can be recovered.
With a bit of luck, sources are discovered that have never been used before. That
is part of my motivation for going to the trouble of buying these vintage magazines
and posting articles like this one which reports on early maser developments. It
delves fairly deeply into the solid state physics of rare earth minerals that some
of the first masers and lasers relied upon to function, including energy band diagrams
and cryogenics. If the
"sugar scoop" antenna looks familiar, it might be due to its rising
to fame...
 "The tech giants Apple and Google are throwing
their joint might behind the use of Bluetooth technology to help governments and
health agencies reduce the spread of Covid-19. And the focus is on contact tracing.
The image above envisages scenarios around
privacy-safe contact tracing using Bluetooth Low Energy. In countries
where the impact of Covid-19 has been minimized - for example Taiwan and South Korea
- contract tracing has been a major element of a national strategy. A number of
leading public health authorities, universities, and NGOs around the world have
been doing important work to develop opt-in contact tracing technology..." Of course
you just knew the example would have the guy responsible for passing the contagion
on to the gal, never the other way around.
"skyworks-sky55501-11-fem-4-15-2020.htm"
 Skyworks Solutions is pleased to introduce the
"skyworks-sky55501-11-fem-4-15-2020.htm" SKY5®-5501-11, a 5 GHz front-end module
(FEM) designed for Wi-Fi enabled devices including handsets and tablets. This advanced
FEM supports simultaneous Wi-Fi and licensed assisted access (LAA) protocols for
high speed data throughput in the 5 GHz WLAN and LAA spectrum. The SKY55501-11
is highly integrated and includes a low-noise amplifier, low-loss bypass path, power
splitter, and single-pole, double-throw transmit and receive switch. The SKY55501-11
builds on Skyworks' portfolio of revolutionary products for 5G applications. The
SKY55501-11 is a highly integrated, 5 GHz front-end module (FEM) that supports
simultaneous 5G WLAN and licensed assisted access (LAA) systems. The SKY55501-11
incorporates a 5 GHz low-noise amplifier (LNA) with bypass supporting 5G WLAN
and LAA...
Since 2003, Bittele Electronics has consistently provided low-volume, electronic
contract manufacturing (ECM) and turnkey PCB assembly services. It specializes in
board level turnkey PCB assembly for design engineers needing low volume or prototype
multi-layer printed circuit boards.
Free Passive Components: Bittele Electronics is taking one further
step in its commitment of offering the best service to clients of its PCB assembly
business. Bittele is now offering common passive components to its clients FREE
of Charge.
 Question: If a fuse is rated at 3 amps, at
what value of current should it "blow?" Answer: Not at 3 amps. As this Littelfuse
company advertisement from a 1954 issue of Radio & Television News
magazine informs us, fuse ratings do not indicate the current value at which a fuse
opens to protect a circuits, but rather the maximum current level at which it will
NOT blow (open circuit). The same goes for circuit breakers. Various types of fuses
are available to handle certain types of applications. For instance, a highly capacitive
load will according to the well-known equation iC(t) = C * dv/dt could draw a very
large amount of initial (inrush) current if there is not enough series resistance
to limit it to prevent a standard fuse from blowing. The same goes for a heavy physical
inertial load at startup (e.g., an air compressor motor). Highly inductive loads
can cause extreme counter-emf currents to be impressed at shutdown. Both of those
circuits...
 Randy Rogers*, AD7ZU, mentioned in the May
2020 issue of QST magazine the Smith Chart software called "SimSmith," by Ward Harriman, AE6TY. SimSmith first appeared around
2011. Being written in Java, it will run on any operating system that supports Java
(Win64, Win32, Apple Mac OS X, Solaris, and Linux). If you are using Win64 as I
am, you will want to download the "windows64-with-JRE.exe" file. Windows security
will try to block it, but it is safe to run after your antivirus program scans it
and gives a green light. AE6TY recommends using the installation files rather than
just downloading the "SimSmith.jar" file even if you already have a version of Java
installed. When launching the program, the window might not be very large, so grab
a corner and stretch it out so the components are easier to see. After playing around
with SimSmith for a while, you might want to click on the "SimSmith->preferences"
menu selection...
 "Testing last month at the Army's Yuma Proving
Ground in the Arizona desert showed a
precision-guided artillery shell that destroyed an enemy target
from nearly 40 miles away during a recent live-fire exercise. The demonstration
of the emerging Long Range Precision Fires program had an Army 155-mm howitzer that
blasted a Raytheon Excalibur GPS-guided artillery round out to ranges twice that
of what existing artillery weapons. The new smart munitions weapon in development,
called Extended Range Cannon Artillery, not only preserves the GPS-guided precision
attack options of the Excalibur ammunition, but also extends attack ranges from
roughly 19 miles to almost 44 miles..."
 Here's a little dose of Ham comedy to help
take the edge off a busy day - straight from the ARRL's QST magazine in
a piece entitled, "Blonde
QRM." It's a little bit kooky by today's standards, but in 1940 the style of
humor it fits right in. This could easily have been the plot in an old TV show like
The Honeymooners, or one of the radio sitcom programs like The Life of Riley. It
reminds me of how in the "Nancy Drew Detective," movie from the 1930s, Ted is a
Ham radio operator, and he tells his fellow Ham that he has experienced "local QRM"
when Nancy Drew suddenly enters his shack (Nancy is a blonde). QRM, by the way,
is Ham lingo for man-made signal interference, as opposed to QRN, which is atmospheric
or "natural" signal interference...
"ConductRF-High-Flex-VNA-Test-Cables-4-8-2020.htm"
 ConductRF offers RF Engineers a large selection
of "ConductRF-High-Flex-VNA-Test-Cables-4-8-2020.htm" Hi Flex cable for vector network
analyzers (VNAs). We have standards for applications at 18-40 GHz, 50 GHz &
70 GHz. Our torque resistant connector heads and phase stable constructions
ensure great performance for many tests to come. Other key features include: 2.92 mm,
2.4 mm & 1.85 mm connector options, low VSWR & insertion loss,
low phase change with flexing, options available swept right angle connectors. 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,
50 GHz, & 70 GHz, these cables offer cost leading alternatives to
original OEM VNA cable solutions...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products such
as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters.
Since the conception of WFT, we have introduced products that have been purchased
by a wide range of customers, from hobbyists to education facilities to government
agencies. Worldwide customers include Europe, Australia, and Asia. Please contact
Windfreak today to learn how they might help you with your current project.
 Radio control (R/C) systems operating in
the 2.4 GHz ISM band, using one of or a combination of frequency hopping and
direct sequence spread spectrum scheme, have been in widespread use since the early
2000s. As with any new technology, there was a lot of reluctance to adoption of
the systems based on a few reports (valid or not) of performance issues - primarily
lack of control range where communications between the transmitter (Tx) and receiver
(Rx) with a pilot and aircraft was lost and a crash ensued. Tx power was already
at the FCC-mandated maximum, so manufacturers quickly improved receivers by adding
diversity with a second Rx antenna. The receiver microprocessor continuously monitors
signal integrity from both antennas and uses the best one. It is the same scheme
that was already being used by WiFi routers also operating at 2.4 GHz...
 It might seem like GaN (gallium nitride) as an RF semiconductor has been around forever,
but it has only been available in affordable commercial production quantities for
a little over a decade. When I worked at RFMD (through 2007, now Qorvo), their labs
were still working on growing a boule greater than 2" in diameter, and military
/ space applications we the primary customers. 3" seemed to be the industry goal
for moving into the commercial realm for both RF and power supply products. Dave
Browne has a good article on his Microwaves & RF website entitled,
"Bump up Semiconductor Efficiency with GaN," that delves into the
technology. "GaN is a semiconductor material that's well-suited for the fabrication
of high-power, high-frequency, as well as ultraviolet LED devices..."
 "The U.S.
semiconductor market is still trying to understand and adjust
to the global coronavirus pandemic. In mid-March, the U.S. stock market was still
trying to understand what was happening with the global coronavirus pandemic, having
lost nearly 20% of its value in one week. Cooling-off periods (also called 'Circuit
Breakers') automatically stopped overheated trading at different intervals. Market
indexes fell sharply, as shown in a chart from Google Finance, which shows the relative
performance over the first part of the year for both the Dow Jones Industrials and
NASDAQ. It's been a roller-coaster ride since that date, with the market rising
sharply last week and once again tumbling to start off this week..."
 As reported in this 1967 Electronics World
magazine piece, lasers were still the things of science fiction to most people.
Real-world applications seemed to be far off in the future, but in fact, work was
underway setting the stage for today's blazingly fast communications systems. The
author here references attaining 5 THz optical transmission speeds through
fiber and through the air. At the time, a laboratory filled with bulky prototypes
chassis and optical tables were required to get those results. I can remember reading
articles in the 1970s when laser power output was measured in "Gillette power," referring to the beam's ability to burn through
a number of razor blades (a big deal at the time). In 2020, devices that greatly
surpass 5 THz are available in consumer quality IC packages...
 RF Cascade Workbook 2018 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. 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...
 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. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
 A column titled "Radio-Electronics Monthly Review" appeared in each issue of Radio-Craft
magazine. As now, things were moving quickly at the time. With WWWII recently ended,
a lot of the new technology developed to help beat back Nazism and Communism was
being transferred to peacetime uses. The May 1947 issue contained, amongst other
items, info regarding how radio servicemen were organizing efforts to get its ranks
educated on FM sets as AM was being replaced and/or supplemented with the new miracle
noise-free broadcast systems. It also reported that the IRS decided not to go forward
with earlier plans to tax television shows being displayed in public places. Attempts
to tax the air that you breathe are to this day still being worked on, though. The
U.S. Bureau of Standards (now NIST) announced adoption of international standards
of measure for certain electrical units...
 Some hard core bikers consider an electric-powered
Harley to be sacrilegious. Can a Harley-Davidson that doesn't make the classic "poTAYto
- poTAYto - poTAYto" be considered a Harley? This article on the Electronic Design
website does a great job of summarizing all the technical features of H-D's 2020
LiveWire all-electric motorcycle (first released in 2019). The
number of sensors and active feedback stabilization and control features is amazing.
Its anti-lock braking system features a Rear-Wheel Lift Mitigation system that "borrows
the C-ABS sensors and six-axis inertial measurement unit to manage rear-wheel lift
during heavy braking, while balancing deceleration and rider control." Hopefully,
the 553-pound (~same as
ICE version), $30k bike doesn't rely too heavily on all the computer
control to the point that its ultimate stability is as dependent on microprocessor
control that it has become like the Boeing
737 MAX's
MCIS...
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 265,628 products from more than 1380
companies across 313 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
 Take a
break from the drudgery with some of these
tech-centric jokes,
song parodies, anecdotes and assorted humor that has been collected from friends &
from websites across the Internet. This humor is light-hearted and sometimes slightly
offensive to the easily-offended, so you are forewarned. I have taken care to censor
out "humor" with reproductive function innuendo and hateful tirades, so it is all
workplace-safe. I have also tried to warn of any links that will result in audio
clips so you can take appropriate precautions. As usual, there is no easy way to
determine the true origin of any of these jokes. Unless otherwise noted, that prolific
author "Anon" is the progenitor...
 "Pilots on reconnaissance missions could
immediately call in their findings. As soon as the first humans went up in hot air
balloons in the late 1700s, military strategists saw the tantalizing possibilities
of
aerial reconnaissance. Imagine being able to spot enemy movements
and artillery from on high - even better if you could instantly communicate those
findings to colleagues on the ground. But the technology of the day didn't offer
an elegant way to do that. By the early 20th century, all of the necessary elements
were in place to finally make aerial reconnaissance a reality: the telegraph, the
telephone, and the airplane. The challenge was bringing them together. Wireless
enthusiasts faced reluctant government bureaucrats..."
 Alliance Test Equipment sells
used / 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.
Alliance Test will purchase your excess test equipment in large or small lots. Please
visit Allied Test Equipment today to see how they can help your project.
 Working crossword puzzles can be contagious.
This April 12, 2020,
tech-themed crossword puzzle may even go viral - the second in
a series. It contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc., which I have personally built
over nearly two decades. That includes the cause for our planet's current dilemma.
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...
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. Some quoted items have been shortened
to save space. About RF Cafe.
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