See Page 1 |
2 |
3 |
4 | of the April 2020 homepage archives. Friday 17
 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
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 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 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
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Thursday 16
 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 Solutions is pleased to introduce
the 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
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services. It specializes in board level turnkey
PCB assembly for design
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Wednesday 15
 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 offers RF Engineers a large selection
of
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,
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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.
Tuesday 14
 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,
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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."
Monday 13
 A column entitled "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
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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
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Sunday 12
 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.
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