 Friday 17
 The problem of and concern about our country's
youngsters seemingly not being overly interested in
pursuing technical career paths is a theme often heard in the tech news media
and workplaces. As our world grows increasingly automated and everything from light
bulbs to telephones and automobiles are so packed with "no user serviceable parts
inside," there seems to be little motivation for an otherwise potential budding
tinkerer to take stuff apart to discover what makes it work. In the "old days" like,
say, 1955, products were much more accessible to kids' curious nature and explains
why fostering the next crop of engineers, scientists, and technicians took care
of itself. You might think so, but alas, the dilemma evidently persists with each
succeeding generation ...
 Jim Holbrook has a useful guide on the Microwaves &
RF website entitled, "What Are the 8 Most Important Oscillator Specs?"
It begins: "What's the first thing you think of when selecting electronic components?
Chances are it's the processor or something else central to the system. The timing
component may be the last thing on your mind, even though the clock provides the
heartbeat that all signals in the system depend on. Selecting these essential timing
components may appear to be a straightforward process, but one must consider a number
of factors that affect system performance. So, what are the most important specifications
and considerations? Here's a short rundown of the top oscillator parameters ..."
 Here is a fairly simple
quiz on AC circuit analysis. If you are not already comfortable with adding
series and parallel circuits containing resistors, capacitors, and inductors, you
will appreciate the simple formula presented that will keep the sweat level down
;-) . An even simpler form that solves explicitly for the four variables are
as follows: VTotal = √ [(VL - VC)2
+ VR2]
VR = √ [(VT)2 - (VL - VC)2]
VL = VC + √ [VT2 - VR2]
VC = VL - √ [VT2 - VR2]
OK, pick up your pencils... now ...
 Altum RF, a supplier of high-performance millimeter-wave
to digital semiconductor solutions for next generation markets and applications,
announces the opening of its Eindhoven, Netherlands office located on the campus
of Eindhoven University of Technology. "Opening
an office on this university campus gives us the strategic advantages of access
to top engineering talent and to leading-edge electrical engineering research and
development," stated Greg Baker, Altum RF CEO. "We work closely with electrical
engineering research groups and collaborate with other start-ups to develop ground-breaking
technology, so this location is ideal for our company. There is also an excellent
source of high-tech talent in this region, which is important for our expansion
plans in the future ..."
 Back in 2012, I posted a video of the PBS
"Frontline" show (Cell Tower Deaths) that highlighted the dangers cell tower climber
technicians face while working for very low wages. Other news stories since then
have reported on new regulations from OSHA and other agencies that have helped make
the safety issue better, but I haven't seen anything on whether the pay has gotten
any better. There are lots of videos and photos online of
tower climbers
all over the world, but this one showing tower climber Kevin Schmidt making the
ascension to the very top of the now inactive KDLT TV analog broadcast antenna near
Salem, SD, is unique in that the recording was made from a drone platform. It has
more than 12 million views. Capturing this kind of video requires a drone with a
wireless live feed so the pilot ...
 This is pretty amazing: "A recent article
in The New York Times reported that many garage door openers and
keyless vehicle entry fobs in an Ohio town near
Cleveland mysteriously stopped working. While the article invoked The X-Files
and hinted initially that a NASA research center somehow could be involved, the
cause was not so much mystifying as arcane. 'Garage door repair people, local ham
radio enthusiasts, and other volunteer investigators descended on the neighborhood
with various meters,' the May 4 article by Heather Murphy recounted. 'Everyone agreed
that something powerful was interfering with the radio frequency that many fobs
rely on, but no one could identify the source ..."
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Thursday 16
 An alternate title for this article that
appeared in a 1969 issue of Radio-Electronics magazine could have been,
"How
to Build a J-K Flip-Flop." Author Leonard Geisler takes the reader through a
step-by-step assembly of a functional J-K flip-flop using a collection of 1- 2-
and 3-input NAND gates. The 1-input NAND, in case you are wondering, is used as
an inverter. The piece reads like an in-depth first-semester electrical engineering
technician course textbook. In the process of building the J-K, an R-S (reset/set)
flip-flop is described. Nowhere does Geisler offer an explanation of from where
the "J" and the "K" input labels come. According to electrical engineer Sourav Bhattacharya
blog, it was Dr. Eldred Nelson of Hughes Aircraft who first coined the term J-K
flip-flop ...
 Testing multi-antenna systems such as phased
array or beamforming antennas requires a test system capable of providing multiple
signals with constant phase relationships between them. The coherent test signals
must have a specific or definable phase difference (relative phase) and definable
amplitude. Some of the challenges for such a test system include compactness, phase
control capability and simplicity in handling. In particular, phase stability between
the channels is of importance. This
Generating Multiple Phase Coherent Signals–Aligned
in Phase and Time application note explains how to generate phase coherent signals.
It details what to consider and how to configure the test setup ...
 This you need to see. The full story behind
this video is unknown, but supposedly customers were complaining about poor reception
associated with the Bear Creek Road microwave station somewhere in northern California.
Upon inspection, the technicians discovered a small hole in the radome. When the
cover was pulled away, according to the video somewhere between 35 to 50 gallons
of acorns spilled out.
You can see the bulge in the radome before emptying. The tech probably thought the
water drain hole was clogged and it was full of water. From a National Geographic
story: "Walter Koenig, a senior scientist with the Cornell Laboratory of Ornithology,
says he's pretty sure the the acorn woodpecker ..."
 The term "ovonic" - a fairly unfamiliar word
these days - appeared in the May edition of Radio-Electronics, in an article
entitled, "All About Ovonics," just a few months after this news item ran in the
January issue (which I posted last month). Ovonics is a portmanteau of "Ovshinsky"
(from Stanford R. Ovshinsky, the inventor) and "electronics." Read the "All About
Ovonics" article for a deeper dive into the subject. The big deal, which turned
out to be not a big enough deal, was the use of
amorphous "glassy" compounds as semiconductors rather than the standard crystalline
silicon structures. Maybe someday an enterprising genius inventor type will give
a rebirth to the concept ...
 "The Air Force said it successfully shot
missiles out of the sky with a ground-based laser system that it plans to make small
enough to fit on its aircraft. The Self-Protect High Energy Laser Demonstrator Advanced
Technology Demonstration Program, or
SHiELD , conducted the tests on April 23, an
Air Force Research Laboratory statement said Friday. 'The successful test is a big
step ahead for directed energy systems and protection against adversarial threats,'
said Maj. Gen. William Cooley, AFRL commander. 'The ability to shoot down missiles
with speed-of-light technology will enable air operation in denied environments.'
During the tests at White Sands Missile Range, N.M., the laser system engaged and
shot down multiple air-launched missiles in flight. It was not immediately clear
whether the laser ..."
 SF Circuits' specialty is in the complex,
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Wednesday 15
 One of the monthly columns in R/C Modeler
magazine, written by Chuck Cunningham, entitled "Cunningham on R/C," that reported
on the current state of radio control, which had only fairly recently evolved into
fully solid state, proportional control systems. Anyone involved in electronics
is painfully familiar with the weird kinds of issues that crop up in complex circuits
that operate in hostile environments. The March 1970 issue contained part of an
article authored by D. L. Klipstein, Director of Engineering, Measurement Control
Devices, entitled, "Murphy's Law: The Contributions of Edsel Murphy to
the Understanding of the Behaviour of Inanimate Objects.*" Only a few of the
items were printed in Cunningham's column, but I managed to locate a copy of the
full article ...
 This is a story with a lesson learned by
the author and thousands of others ever since electric power appliances and tools
first became available. Fortunately, his Ham buddy was not permanently harmed, but
even today with all the effort put into educating the public, people continue to
use ungrounded (2-wire type, or with the ground prong removed) extension cords in
conjunction with 3-wire power cords on tools and end up
electrocuting
themselves (or somebody else). I've told the story before about a friend of mine
from high school who shortly after graduation was making a piece of furniture in
a garage that had a damp dirt floor, and was electrocuted to death by the metal-framed
circular saw that had no ground connected. Nowadays we often have power provided
by a GFCI receptacle ...
 Axiom Test Equipment, an electronic test
equipment rentals and sales company, has published a blog post entitled, "Keeping
Self-Driving Vehicles on the Road," which discusses the technical and test requirements
for the mm-wave radars and optical wavelength Lidar systems used for precise, fast-acting
sensing and processing. Sophisticated test equipment is required for development,
all of which Axiom Test Equipment can provide on a sale or lease basis. Self-driving
cars, also known as autonomous vehicles, are literally right down the road. These
electronically guided vehicles of the future will be built with advanced driver
assistance system (ADAS) hardware and software, using several different technologies
to detect and track other cars, pedestrians, and objects on the road and steer the
vehicle ...
 I assume the "real"
RoboCop won't be sporting a hokey helmet and
will handle inclement weather interfaces. This concept is actually a good idea based
on how dangerous traffic stops have become for police officers. "The new cop robot
was created to make police stops and arrests safer for everyone. We have all been
stopped by a cop a few times and it is never a pleasant experience. However, according
to Reuben Brewer, a Senior Robotics Research Engineer in SRI International's Applied
Technologies and Science Department (ATSD), it can even be a downright dangerous
one. According to the video's description ...
 My daughter, Sally, in addition to owning
and operating a very successful horse riding school named Equine Kingdom Riding
Academy, has a rather large eBay store she uses as a venue for selling items purchased
at the local Goodwill "Bins" store. She often buys vintage toys with electronics
features - sometimes working and sometimes not. A properly functioning vintage toy,
be it a stuffed animal or a game of some sort, can make a huge difference in the
resale price. When that is the case, she sends them home with me to attempt a repair.
Many times the problem is corroded contacts from leaky batteries. A dental pick
and some isopropyl alcohol usually solves the problem. When that doesn't work, it's
time to open 'er up for a deeper look. Over the years I have found problems ranging ...
 Alliance Test sells
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...
Tuesday 14
 This photo of
Ray Dolby holding one of his prototype noise reduction circuits is probably
the most widely published of him and therefore the most iconic of the Dolby noise
reduction system. Audiophiles of the era (and today for that matter) immediately
recognize the man who took the hisses and pops out of their beloved music. I always
like to keep in mind when reading article like this one in a 1971 issue of Radio-Electronics
magazine is that when it was originally published, Dolby had not yet become a household
word and news of his accomplishment was just getting out. Many articles, books,
and research papers have been written on how the Dolby system works. At least five
of them from the groundbreaking era have been posted here on RF Cafe, so you can
get some insight into the excitement. The technical term "companding" (compressing
and expanding) was being seen in print for the first time ...
 Microwave Journal has developed and
published an enhanced
Microwaves Basics section online. This comprehensive library is based on content
from the books "Microwaves and Wireless Simplified," by Thomas S. Laverghetta and
"Handbook of RF, Microwave, and Millimeter-Wave Components," by Leonid A. Belov,
Sergey M. Smolskiy and Victor N. Kochemasov, both published by Artech House, plus
"Mixer Basics Primer: A Tutorial for RF & Microwave Mixers," by Ferenc Marki &
Christopher Marki of Marki Microwave. If your work involves microwave or wireless
communications technology or you just want to brush up on your technology basics,
the Microwave Basics Library provides a good understanding of key concepts ...
 "Rediscovery
of FM Broadcasting" could be a contemporary headline. The decline of broadcast
radio has been a major concern of station owners for well over a decade since Internet
and satellite radio has dominated the venue through which listeners access radio
stations. Local broadcasters have long aired syndicated programs that include national
advertising, but the money to pay for those segments came from revenue supplied
largely by local companies. FM broadcasting began commercially around 1945 in the
familiar 88-108 MHz band yielded by the military following World War II,
and grew in number of stations very rapidly in the first few years. Then, it began
a decline for a few more years until finally leveling off after about a decade.
Even though FM had a clear advantage (literally) over AM because of electrical noise
immunity ...
 Centric RF is a company offering from stock
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RF today ...
 "Hologram visitors, indoor navigation, facial
recognition security, and voice-controlled rooms are coming to a hospital in South
Korea. When Yonsei University Health System opens its newest hospital next year,
in Yongin, about 25 miles outside of Seoul, it will be decked out with some of tech's
hottest gadgets. Very sick patients in isolation rooms can visit with holograms
of their loved ones. Visitors will find their way around the hospital using an augmented
reality (AR)-based indoor navigation system. Authorized medical workers will use
facial recognition to enter secure areas. Patients can call a nurse and control
their bed, lights, and TV with an Alexa-style voice assistant ..."
 The new
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intercept (TOI) at 1 GHz: +20 dBm (typ.) DANL at 1 GHz: −153 dBm
DANL at 1 GHZ with optional preamp: −167 dBm Ready for cloud based test ...
 At VidaRF, the phrase 'Providing Simple
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Monday 13
 When the electronics product world consisted
of vacuum tube based circuits, the physical sizes of standard fixed-value passive
resistors, inductors, and capacitors were not of much concern in terms of how
much volume they consumed. R's, L's, and C's, had wire leads protruding from their
molded bodies, or in the case of larger power supply filtering capacitors had solderable
tabs. Point-to-point wiring consisted of components and hookup wire suspended in
the air between solder terminal strips and tube base tabs. Even with miniature (peanut)
tubes, all but the largest passives had no significant impact on overall unit size.
Once semiconductors came onto the scene, everything changed. Suddenly, even the
standard 1/4 W carbon resistor and tantalum capacitor became a significant
factor when attempting to reduce size ...
Why IP2 Matters for Wideband
Amplifiers
 In the days before wideband and single-conversion
radio systems, few system designers worried much about
2nd-order intercept point (IP2) power levels
because the likelihood of two or more signals generating significant inband spurious
products was small. Today's systems are fundamentally different. This article by
Chris DeMartino comments on Custom MMIC's application note #106 entitled "IP2 Measurements of Wideband Amplifiers." He
begins, "Amplifier distortion exists in several forms. One form occurs when an amplifier
is driven by a signal with a sufficiently large amplitude, thus causing the amplifier
to approach its P1dB. Another type of distortion involves the scenario in which
two signals - with frequencies that are different but still close to one another
in value - are driving an amplifier, resulting in second- and third-order distortion ..."
 Here are a few
tech-themed comics from the April 1967 edition of Popular Electronics
magazine depicting the perception of techies during the era. As mentioned before,
stereo equipment was a big deal in the era, back before most people listened to
music through ear buds attached to smartphones. When in the USAF in the early 1980s,
a sure sign of hipness was to have 19" equipment rack in your barracks room, stuffed
full with a reel-to-reel tape deck, a high end AM/FM receiver ("tuner," to the audiophile),
power amplifier that could deliver at least 200 W per channel, a dual cassette
deck, turntable (referring to it as a "phonograph" revealed your squareness). Of
course no self-respecting stereo aficionado would be caught dead with an 8-track
tape deck in the rack ...
 Transient Specialists specializes in
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 "Southwest Research Institute (SwRI) has
developed a cybersecurity system to test for vulnerabilities in automated vehicles
and other technologies that use GPS receivers for positioning, navigation, and timing.
GPS spoofing is a malicious attack that broadcasts
incorrect signals to GPS receivers, while GPS manipulation modifies a real GPS signal.
GPS satellites orbiting the Earth pinpoint physical locations of GPS receivers embedded
in everything from smartphones to ground vehicles and aircraft. SwRI designed the
new tool to meet United States federal regulations. Testing for GPS vulnerabilities
in a mobile environment had previously been difficult because federal law prohibits
over-the-air re-transmission of GPS signals without prior authorization ..."
 RF Superstore launched in 2017, marking
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Sunday 12
 Since 2000, I have been creating custom
engineering- and science-themed crossword puzzles for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out
on whether or not this type of mental challenge helps keep your gray matter from
atrophying in old age, but it certainly helps maintain your vocabulary and cognitive
skills at all ages. A database of thousands of words has been built up over the
years and contains only clues and terms associated with engineering, science, physical,
astronomy, mathematics, chemistry, etc. 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 ...
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