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5 of the May 2019 homepage archives. 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..."
 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...
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,
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...
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
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.
Please visit Allied Test Equipment today to see how they can help your project...
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
various RF and
Microwave coaxial components, including attenuators, adapters, cable
assemblies, terminations, power dividers, and more. We believe in offering high
performance parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz
at power levels from 0.5-500 watts are available off the shelf. Order today,
ship today! Centric RF is currently looking for vendors to partner with them.
Please visit Centric RF today...
 "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
R&S®FSVA3000 signal and spectrum analyzer has everything needed to keep
up with demanding measurement applications. An analysis bandwidth of 400 MHz, an
outstanding phase noise of -120 dBc/Hz and a high dynamic range. Capabilities
that used to be only available for performance instruments have now become
accessible to everyone. Key Facts Frequency range of 10 Hz to 4 GHz, 7.5 GHz,
13.6 GHz, 30 GHz or 44 GHz (up to 500 GHz with external harmonic mixers from
Rohde & Schwarz) Analysis bandwidth up to 400 MHz SSB phase noise at 10 kHz
offset (1 GHz): -120 dBc (1 Hz) Third-order 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
Solutions for Complex Connections' is more than just a slogan – it's a mindset,
a mission, and a driving force behind everything we do. Their pledge is to design
and distribute high performance, cost effective
RF Microwave products to fit each customer's unique applications.
Please visit VidaRF today to see how their lines of attenuators & terminations,
directional couplers, power dividers, coaxial connectors, and circulator & isolators
can be of use to your project. "When the standard just will not do, VidaRF has the
solution for you!"...
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
EMC test
equipment rentals and carries a complete line of ESD guns, surge immunity test
equipment, and EFT generators. Rentals available for military (Mil-Std 461), automotive
(ISO 7637), and commercial (IEC 61000-4) EMC testing. Flexible terms, accredited
calibrations and technical support on EMC testing equipment offered. Equipment consists
of top EMC Test System manufacturers, including Teseq, Thermo Keytek, EM Test
and EMC Partner...
 "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
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!
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...
These archive pages are provided in order to make it easier for you to find items
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