See Page 1 |
2 |
3 |
4 | of the April 2020 homepage archives. Friday 10
 RF Cafe visitor Mike M. reminded me
of "Madman Muntz,"
who was a widely known television commercial personality on the West Coast from
the 1950s through the 1970s. Earl William "Madman" Muntz's zany live and animated
commercials were used highly successfully in selling cars, including one he himself
designed and manufactured called the Muntz Jet. Along with being a master salesman,
Madman Muntz was also a self-taught electronics engineer of sorts. He is credited
with developing the first 4-track stereo tape deck for cars, which was a precursor
to the 8-track tape deck. What Mike mentioned specifically was the line of Muntz
television sets. Not satisfied to merely manufacture TV sets, Muntz created an entire
service shop and fleet of mobile television trucks. It was kind of an early version
of the Nerd Herd. Based on the Madman's trademark method of minimizing the number
of components used in his products...
 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...
 This ad for
Connecticut Telephone & Electric Division appeared in the January 1945 edition
of Radio News. The company, as the name suggests, manufactured communications equipment,
but as the name does not necessarily suggest, it also made radios and accessories.
The Radio Museum website has a collection of photos and specifications about some
of the equipment, such as the Vacuum Tube Detector Set Type DT-3 and Sodion DR6
single-tube receiver. Connecticut Telephone & Electric Division began operations
at the dawn of the wireless communications age and produced a lot of materiel for
the armed forces in World War II. Some of the vintage Connecticut Telephone &
Electric Division components appear occasionally on eBay.
 "A radar system known as
Space Fence, which can track material in space as small as 10 cm, is fully operational,
the U.S. Space Force announced. Using enhanced S-band radar, the Space Fence improves
on previous capabilities of the Space Surveillance Network in tracking objects such
as commercial and military satellites, depleted rocket boosters and space debris
in low, medium, and geosynchronous Earth orbit regimes, Space Force officials said
on Friday. The SSN has tracked 26,000 objects already accounted for in space, and
the new system is expected to vastly increase that figure, essentially offering
a catalog and location of every object in space. 'Space Fence is revolutionizing
the way we view space by providing timely, precise orbital data on objects that
threaten both manned and unmanned military and commercial space assets..."
 Modelithics, Inc. and Mini-Circuits have
expanded their partnership by developing new high-accuracy simulation models for
several packaged
Mini-Circuits amplifiers. In total, 14 new substrate-selectable amplifier models
have been developed. These data-based models were extracted by performing broadband
S-parameter and noise-parameter measurements with a Keysight PNA-X vector network
analyzer (VNA), as part of a Maury Microwave ultra-fast noise parameter measurement
setup. Modelithics now offers over 68 models, representing over 130 individual Mini-Circuits
components, that include amplifiers, filters and splitters, among others. All the
new amplifier models are currently available for FREE for use within Keysight Technologies'
PathWave Advanced Design System (ADS)...
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave filters,
diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity,
and waveguide designs, as well as state of the art high performance suspended substrate
models. Through a continuous process of research and development, they have established
a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop,
diplexer, and more. Established in 1979. Please contact Reactel today to see how
they might help your project.
Thursday 9
 Female RF Cafe visitors might be interested
to learn from this "Within the Industry" column which appeared in the 1958 Radio &
TV News magazine of
Helen Staniland Quam being elected president of the Association of Electronic
Parts & Equipment Manufacturers, Inc. She was the first woman to head a major
trade group in the electronics industry. A couple pages away in the same issue carried
a half-page advertisement for her Quam-Nichols Company. The company was a primary
supplier of audio speakers for radio and television original equipment manufacturers
(OEMs) and for commercial loudspeaker installations. Sadly, other than a mention
or two in vintage electronics magazines, there is not much about her accomplishments
to be found on the Web.
 This advertisement for the
Quam-Nichols Company's famous line of speakers appeared in the the June 1958
issue of Radio & TV News magazine, just a couple pages after a "Within
the Industry" column announcing Helen Staniland Quam having been elected president
of the Association of Electronic Parts & Equipment Manufacturers, Inc. The company,
born in Chicago, Illinois, is still in business, but now going by the name Quam
Speakers. From their website: "Commercial loudspeaker products have been our sole
focus since 1930. This means nearly 90 years of real world learning, testing, refining,
re-inventing, adapting - not just our products but also our way of working with
our customers. We understand that commercial loudspeakers are often the last thing
on your mind, but it's the first thing your clients hear..."
 "It's 10,000 times more accurate than the
gyros in your cell phone, but costs just $50. As useful as GPS is, it's not a system
that we can rely on all the time. There are many situations in which GPS might not
be available, such as when you're inside a building, driving through a tunnel, on
a battlefield, in a mine, underwater, or in space. Systems that need to track location,
like your cell phone, an autonomous car, or a submarine, often use what are called
Inertial Measurement Units (a combination of accelerometers and gyroscopes) to estimate
position through dead reckoning by tracking changes in acceleration and rotation.
The accuracy of these location estimates depends on how accurate the sensors in
those IMUs are. Unfortunately, gyroscopes that can do a good job of tracking rotation..."
 Cadence| AWR will host a free webinar on
April 28 at 12:00 pm EDT entitled "Facts
and Fallacies in RFPA Waveform Engineering," presented by RF power amplifier
(RFPA) expert Dr. Steve Cripps. What: Waveform engineering has been an important
concept in RF power amplifier (RFPA) design, resulting in the definition of important
new PA modes. The concept can, however, be taken too far. Sponsored by Cadence,
this "Facts and Fallacies in RFPA Waveform Engineering" free webinar is presented
by PA expert Dr. Steve Cripps of Cardiff University, who will illustrate some common
misconceptions surrounding waveform realization using various design examples, including
both switched and analog cases...
 Echo 1 was put into orbit on August
12, 1960. This article was written 2½ years earlier in 1958 by Radio-Electronics
editor Hugo Gernsback. A technology visionary and prolific inventor and writer,
Mr. Gernsback astutely outlined the vast number of advantages that had already been
and would in the future be afforded the science community by virtue of a satellite's
perspective from space. Two of the Soviet Union's
Sputnik satellites had revealed the surprisingly irregular shape and gravitational
influence of the Earth, information about the upper atmosphere, and aspects of space
environment effects on radio communications. America was scrambling to catch up.
Gernsback and others postulated the configuration of active relay transceivers powered
by solar cells and storage batteries, satellite-based television and radio...
 In keeping with the effort to spread the
news about how to protect yourself from the Wuhan Flu until an inoculation can be
developed, here is the "Stayin'
Alive" YouTube sensation produced from disparate locations by some stay-at-homers
in Sweden. BTW, in case your weren't around during the 1970s disco era, the
Bee Gees are the (B)rothers
(G)ibb. If you find yourself quarantined (literally or effectively), then you can
relate to "My Corona Home,"
a parody of the Beach Boys'
"Kokomo" song.
 Electro-Photonics is a global supplier of
RF & Microwave components.
Their products include SMT hybrid and directional couplers, wire bondable passive
components, mounting tabs, filters, transmission lines, and very useful test boards
for evaluating components (spiral inductors, single-layer capacitors). The Electro-Photonics
team can support your small R&D design requirements with RF & Microwave
test fixtures and save you valuable design and characterization time. Please take
a moment to visit Electro-Photonics' website and see how your project might benefit.
Wednesday 8
 Part VI of the multi-month series of articles
on antenna principles which appeared in Radio-Craft magazine covers directive
arrays with metal-screen reflectors. Metal-screen, wire, and mesh reflectors are
discussed as reflector surfaces for broadside array, the collinear array, and billboard
array collections of dipole elements. An interesting statement by author Jordan
McQuay is, "It is more practical and efficient to use a reflector screen [as opposed
to reflector dipole elements], particularly if there are a large number of dipoles.
Such a non-resonant reflector is easier arid cheaper to construct, and provides
a better broad-band response than a resonant reflector." I don't know enough about
antenna deign to determine whether with modern methods of simulation and construction,
if that still holds...
 Reading trade journals is always given as
one of the main ways cited by engineers on career surveys for continuing education.
Engineering whitepapers, pamphlets, books, magazines, and chapter examples listed
here are a small sample of a lot of new items that are offered for
FREE through TradePub. The
publishers make them available to qualifying people as a promotional campaign for
their full line of offerings. Whitepaper topics include careers, manufacturing,
and engineering, while magazine titles include Microwave Engineering Europe, Electronic
Design, and Microwave Product Digest. Note: I earn a few pennies (literally) when
you download one of these or the many other pubs available, so please help yourself.
 The Design News website published
their list of engineering schools with alumni that earn the
highest salaries. As usual, all the familiar names appear, but with some shuffling
of positions. For a reason I still do not understand - and I'm not knocking it -
Harvey Mudd College leads the pack with an entry level salary of $90,700 and a mid-career
salary and $161,800. Stanford was #2 and MIT #3. For reasons I do understand, military
academies consistently rank highly (USNA #4, USMMA #10, USCGA #19). Says, the article:
"As part of Engineering Week, we're presenting the 2020 report from PayScale
(2019 report)
shows which schools are turning out the highest paid grads with a bachelor's or
graduate degree. Two years ago we posted the results of PayScale's study that only
included grads with bachelor's degrees. The difference in the lists is surprising.
PayScale defines engineering schools as those public or private institutions that
grant more than 50 percent of their undergraduate degrees in math, sciences, computer
science, engineering, or engineering technology majors..."
 Use of a
load line chart is a fast way of selecting the bias (operating) point and operational
range for nonlinear devices. Notice that I didn't specifically say for transistors
because this particular article deals with load lines for vacuum tubes. Almost nobody
has any need for tube load line charts anymore, but the skill needed to interpret
load lines for transistors is fundamentally the same as for tubes. Substitute Vce
(collector-to-emitter voltage) for Plate Volts and Ic (collector current) for Plate
Milliamperes and you have equivalence. Popular Electronics magazine ran
this "After Class" tutorial series covering a broad variety of topics for many years.
There is a short quiz at the end...
 And now,
the cousin of the
Flux
Capacitor --- the
Spin Capacitor!
"In what is claimed to be a world first, physicists have developed a so-called spin
capacitor that could herald new electronics that require less power and generate
less heat. The advance by scientists at Leeds University generates and holds the
spin state of electrons for a number of hours compared to previous efforts that
held the spin state for a fraction of a second. Their results are published in Science
Advances. A conventional capacitor holds energy in the form of electric charge and
the development from Leeds does this also whilst storing the spin state of a group
of electrons. According to the university, this could lead to a storage device measuring
one square inch that could store 100 terabytes of data..."
 Let
me start by saying this is NOT the COVID-19 form of coronavirus. It is patent
US10130701B2 issued
to a UK research entity. A CNIPA (China
National Intelligence Property Administration) website search does not show any
coronavirus patents - maybe the
Wuhan Institute
of Virology application is still pending. A search on the USPTO website for
"coronavirus"
(ttl) turns up 75 results. I'm not sure which makes me more uncomfortable - a communist
country's patent office that shows no coronavirus patents or a representative republic
country's patent office that shows scores of them, with 5 having
China (cn) as the assignee country (acn).
 MPDevice (MPD) has become a trustworthy
and reliable company in the global RF market as a manufacturer of
passive RF Devices. Included
are attenuators and terminations, coaxial connectors, adapters, and cable assemblies,
DC blocks, surge arrestors, power combiner / dividers, and directional couplers.
The Korean Telecommunication market is now entering into the era of hyperconnected
society. With continuous enhancement in R&D capabilities and quality control,
MPD will continue in an effort to become the No. 1 technologically innovative
company with a focus on the emerging 5G marketplace.
Tuesday 7
 Famous quotation books are full of statements
made by people - many of them "experts" - throughout history which have proven to
be hilariously wrong, and unfortunately some have been tragically wrong. Thomas
Watson, president of IBM, in 1943 famously predicted on digital computers, "I think
there is a world market for maybe five computers." In 1946, 20th Century Fox's Darryl
Zanuck declared, "Television won't be able to hold on to any market it captures
after the first six months. People will soon get tired of staring at a plywood box
every night." Virtually on the eve of the PC revolution (1977), DEC founder Ken
Olsen, "There is no reason anyone would want a computer in their home." British
Prime Minister Neville Chamberlain assured his countrymen regarding Adolph Hitler's
assurance of nonaggression, "I have returned from Germany with peace for our time".
In 1947 when Radio-Craft magazine founder and editor wrote this article
telling of the many in-the-know types who were predicting a
grave future for commercial broadcast radio once television became a common
fixture in households...
 RF Cafe typically receives 8,000-15,000
website visits each weekday and about half that on weekends.
RF Cafe is a favorite of engineers, technicians, hobbyists, and students all
over the world. With more than 13,000 pages in the Google search index,
RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content
is added on a daily basis, which keeps the major search engines interested enough
to spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be. Advertising begins at $40/month.
 When it comes to low loss transmission media,
it's hard to beat waveguide and open wire. Open wire can exhibit less a couple tenths
of a decibel per hundred feet at low frequencies, but it is very susceptible to
perturbations from nearby objects, wind and moisture. Waveguide exhibits a few tenths
of a decibel per 100 feet at very high frequencies, but it is expensive and difficult
to work with. In the middle is coaxial cable, which for a good quality product of
appropriate size, you can get very low attenuation. As with most things, you get
what you pay for in coax cable. I once used really expensive Andrew (now Commscope)
Heliax coax cable on an S-band radar (2.8 GHz) system that had only a little
more than 1 dB/100 ft, which was necessary from a receiver noise figure
requirement rather than for transmitter power efficiency. This article from
QST covers some of the basics of low loss cable...
 "The
International Commission on Non-Ionizing Radiation Protection (ICNIRP) has released
new guidelines for the protection of humans exposed to radio frequency electromagnetic
fields. The guidelines cover the upcoming 5G technologies, as well as AM and DAB
radio, WiFi, Bluetooth, and the currently used 3G/4G mobile phones. ICNIRP Chairman,
Dr. Eric van Rongen, said the new electromagnetic field guidelines have taken seven
years to develop and are more appropriate than the 1998 guidelines for the higher
frequencies that will be used for 5G in the future. He added that they know parts
of the community are concerned about the safety of 5G and they hope the updated
guidelines will help put people at ease. The guidelines have been developed after
a thorough review of all relevant scientific literature, scientific workshops, and
an extensive public consultation process. They provide protection against all scientifically
substantiated adverse health effects due to EMF exposure in the 100 kHz to 300 GHz
range..."
 Mr. Asem Elshimi has an article entitled
"Make
Sense of Antenna Design and Matching Networks" on the EDN website. He introduces
the basics of EM radiation and ideal antenna formats, then discusses acceptable
compromises based on the application. "When it comes to actual antennas in the real
world, much of our knowledge is empirical. We know very broadly theories that explain
how a point charge radiates (Maxwell's equations), the need for matching (microwave
theory), and how dipole antennas drawn on paper radiate the way they do, but these
laws are nearly useless in solving the real-world problem of antenna design. By
sharing my intuition on how wireless electronics work on a physical level, I hope
to be useful in shaping a broad understanding of antenna design and matching networks
and underscore the value of best practices and hard-earned wisdom..."
(note Fig. 1
antenna
drawings appear to be mine)
 "EE suspects telephone mast engulfed by
fire in Birmingham was an arson attack as celebrities claim Covid-19 caused by new
network ('ØG' video).
Ofcom has warned broadcasters to refrain from spreading rumors that
5G is linked to coronavirus. Telecoms engineers are facing verbal and physical
threats during the lockdown, as baseless conspiracy theories linking coronavirus
to the rollout of 5G technology spread by celebrities such as Amanda Holden prompt
members of the public to abuse those maintaining vital mobile phone and broadband
networks. Facebook has removed one anti-5G group in which users were being encouraged
to supply footage of them destroying mobile phone equipment, with some contributors..."
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
Monday 6
 Whenever I post any of these Radio Data Sheets
from vintage electronics magazines, I attempt to find photos of actual units. Drawings
are good, but actually seeing a for-real example is the best option. This
Admiral Model 6RT44-7B1 phonograph appears on the Radio Attic's Archive website.
As mentioned previously, electronics service shops relied heavily on these Radio
Data Sheets that were printed in monthly magazines like Radio-Craft, Radio News,
and Radio & Television News. The alternative was purchasing service documentation
from the manufacturer (often only available to factory-authorized shops), from Sam's
Photofacts, or some other third-party supplier. Of course experience and intuitiveness
could substitute for documentation, but as many episodes of John T. Frye's
series of "Mac's Radio Service Shop" illustrates, quirky variations in circuits...
 "A new type of graphene amplifier could offer
researchers a unique way to access the electromagnetic spectrum. Engineers from
Loughborough University have designed an optical transistor out of graphene and
a high-temperature superconductor that can
amplify terahertz frequencies, and could unlock a whole new field of potential
technologies. Terahertz waves (THz) have long fascinated scientists, but unfortunately,
their use has been limited by their weak signals. Without an added boost of power,
the wavelengths have been too weak for researchers to harness their potential power
- until now, that is. The amplifier is deceptively simple, made up of two layers
of graphene and the superconductor..."
 "There's a tricky question asked at Google
and Amazon interviews that is bound to stump you. However, worry not as YouTuber
Zach Star is here with the solution in this fun video. The question goes like this:
let's say you have a stick that you will randomly cut in three pieces.
What are the odds that the three pieces created can form a triangle? If the
three pieces are about equal in size, you can make a triangle. If, however, you
have two much smaller pieces, you can not. It should also be known that for a triangle
to be made, the two shortest lengths combined need to be bigger than the third.
How does that relate to our question? Well, you have to watch the video for that..."
 Z-Communications, Inc., announces a new
RoHS compliant VCO (Voltage-Controlled Oscillator) model
SMV0912B-LF.
The SMV0912B-LF operates from 865 to 960 MHz within a tuning voltage range
of 0 to 2.5 Vdc. This low cost VCO features very clean spectral purity performance
of -100 dBc/Hz @10 kHz offset and covers the frequency range with an average
sensitivity of 80 MHz/V. The SMV0912B-LF is designed to deliver 3±3 dBm
of output power into a 50 ohms load while operating over the industrial temperature
range of -40 to 85°C. This high performance VCO is further enhanced by saving precious
energy. It consumes a mere 6 mA of current while operating off a 3.0 Vdc
supply. The SMV0912B-LF features a typical 2nd harmonic suppression of -10 dBc...
 Question: According to the legend on this
graphic, how many confirmed cases of coronavirus do the gray-colored areas have
(answer below)? Look at this "Countries
with Confirmed Cases of Coronavirus" map used in an MSN.com news story. According
to graphic creator Tara, it was provided by the World Health Organization. This
is an example of why the news media should not be unquestioningly believed when
presenting data. Its reporters are for the most part very scientifically and mathematically
ignorant (and some are plain stupid). They do not know how to assimilate and present
numerical information, while pompously demanding that everyone listen to the scientists.
Answer: Exactly 100. Do you understand why?
 Withwave manufactures an extensive line of
metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated 4-port vector network analyzer
(VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations,
DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures
for calibration and multicoax cable assemblies. Frequency ranges from DC through
110 GHz. Please contact Withwave today to see how they can help your project
succeed.
Sunday 5
 Working crossword puzzles can be contagious.
This April 5, 2020,
tech-themed crossword puzzle may even go viral. 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, for reasons
which, if you don't already know, might surprise you...
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.
About RF Cafe. I also
have an extensive list of
Recently Added topics.
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