If you read the physics and geographic news
of the day, most likely you have seen articles on the rapidly increasing
migration rate of the geomagnetic "north pole" over the past few decades. Magnetic
north has never exactly lined up with geometric north (as borne out in geological
samples of rocks), and neither has it ever been uniformly distributed across the
globe. Ancient explorers on terra firma and at sea knew that a magnetic compass
needle did not align with the same stars, moon, or sun position for every location,
after accounting for difference in longitude. That is because the earth's magnetic
field is very nonuniform in strength and does not follow straight lines from pole
to pole as they more generally do from outer space. A correction factor must be
applied to any magnetic north indication based ...
ConductRF, a premier manufacturer of standard
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was an early form of television image capturing tube. Some amateur radio operators
were experimenting with slow scan TV even back when the technology was relatively
new to the world. When this article was written in 1944, there were still large
portions of the United States that did not have television broadcast coverage. Of
course I would argue that at the time of my growing up in the 1960s and early 1970s
a lot of areas - even suburbs - were still not covered by TV signals, based on how
cruddy the reception at my parents' house was. But I digress. The article mentions
that because of the lack of TV coverage, many amateurs did not even have television
receivers (TV sets) in their homes to use along with experimental television transmitters ...
"Welcome to the first issue of
CAS News from Cobham Antenna Systems! Inspired by the richness
of late-spring, we decided to launch this bi-monthly newsletter, to help keep everyone
informed of all the exciting developments going on here at Cobham Antenna Systems
(CAS), in Newmarket, UK. In this issue, the first of many to come, we cover our
presence at two recent key industry exhibitions: AUVSI / Xponential 2019 in Chicago,
USA, and EW-E 2019 in Stockholm, Sweden. At these shows we introduced a new antenna
that is designed specifically for C-UAS (that is, Counter-Unmanned Airborne Systems).
We also take a look at how we are helping Professor Alan Wilson ...
from Kyushu University, Japan, have demonstrated lasing from an electrically driven
organic diode. Reporting their findings in the
journal Applied Physics Express under the title 'Indication of current-injection
lasing from an organic semiconductor,' the researchers circumvented the traditional
issues of organic materials (which due to their inherent resistance, tend to break
down under the high currents required for lasing). A critical step in lasing is
the injection of a large amount of electrical current into the organic layers to
achieve a condition called population inversion ..."
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Everything is relative... just ask Albert
Einstein. The use of terms like "contemporary," "modern," etc., in the titles of
books has always annoyed me. They would be okay if the titles also included the
year or at least the decade to which the claim applies. Not quite as nefarious is
the claim of "high frequency" when describing electronics components since it is
safe to assume that most readers understand the era to which it applies. To a lesser
extent that goes for "high voltage" and "high current." This 1964 advertisement
Oxide-Passivated Silicon Annular Transistors appeared in Electronics
magazine touting the high frequency capability ...
As we approach the 50th anniversary of the
Apollo 11 moon landing, many magazines are publishing articles about the event
and the background leading up to it. I have tagged a couple notable quotes from
astronauts involved that will be posted over the next month or so. The June issue
of Discover magazine included this one as delivered by
Neil Armstrong to the National Press Club: "I
am, and ever will be, a white-socks, pocket-protector, nerdy engineer, born under
the second law of thermodynamics, steeped in the steam tables, in love with free-body
diagrams. ... Science is about what is. Engineering is about what can be." Amen,
CMD299 is a highly efficient GaAs MMIC low noise amplifier ideally suited for
EW and communications systems where small size and low power consumption are needed.
The device is optimized for 30 GHz and delivers greater than 17 dB of gain with
a corresponding noise figure of 3.5 dB and output 1 dB compression point of +7 dBm.
The CMD299 is a 50 ohm matched design which eliminates the need for external DC
blocks and RF port matching. The CMD299 offers full passivation for increased reliability
and moisture protection ...
Andrei Muller, of the Swiss Federal Institute
of Technology in Lausanne will present his
3D Smith Chart
software during the PRIME 2019 event on Monday, July 15th. The talk will start by
presenting the mathematics behind the Smith chart and extended 2D Smith chart from
the group theory of geometry point of view (Kleinian view of geometry). Using the
Maxime Bochert-Klein results on Mobius transformations (among which the Smith chart
constitutive equation belongs). The introduction will show what happens by applying
the voltage reflection coefficient transformation and power wave reflection coefficient
transformation on the grid of the impedance plane, random geometrical objects and
photos. The geometry of these mappings will be then compared with the geometry of
other scattering parameters mappings when applied to the same objects ...
"A new method to develop 2D materials, called
transition metal dichalcogenides, paves the way
for novel applications in optoelectronics and other next-generation electronic devices.
The promise of 2D graphene material for next-generation electronics is well-known
- because of its high conductivity and light weight. However, there are many other
2D materials that also can be used in future electronics applications to bring new
and improved characteristics. Some of the materials in which researchers are particularly
interested are a group of semiconductors called transition metal dichalcogenides,
or TMDs. These materials, a few atoms thick ..."
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Many months have passed since I last posted
one of the Radio Service Data Sheets for vintage radio sets. This one for the
Sentinel Model 217−P portable appeared in the August 1940 issue of
Radio−Craft magazine. Hobbyists and professional electronics service
shops relied on these back in the day because obtaining the information from manufacturers
could be difficult or even impossible. Some companies would not provide service
information for alignment and troubleshooting to businesses that were not officially
endorsed to do so. That left some of the smaller shops and most do-it-yourselfers
without a means to work on sets. Once places like SAMS Photofacts came along with
information packets that could be purchased ...
Carl and Jerry found the appearance and construction
2,400 megacycle transmitters and receivers to be quite odd compared to the equipment
they were used to dealing with. It's sometimes hard to believe such an attitude
of wonder when our world today is utterly filled with wireless devices operating
in the 2.4 GHz ISM band. Author John T. Frye could never have imagined
that such a reality would would exist half a century after his story of the pair
of teenage electronics sleuths. Unlike our postage stamp size integrated assemblies
that cost a few dollars, they speak of "special ultra-high-frequency 'light-house'
tubes with a cavity resonator clamped on top of them." Back to the story, though...
Did you know that police were using radar guns as far back as 1963? ...
Listen in on our latest news as our very
own CEO Paul Blount proudly presents
Custom MMIC's Women in Engineering scholarship
last Wednesday, June 5th 2019 at the International Microwave Symposium in Boston.
In this quick podcast, meet the first three recipients of the scholarship: Sarah
McKinley, Emma Fournier and Grace Remillard. Blount describes each of the women
as "so talented."
This latest report by the Interesting
Engineering website lists a state-by-state accounting of
mechanical engineers' salaries. Data was assimilated from the
U.S. Bureau of Labor Statistics (BLS). The Bureau projects a 9% job growth rate
form 2016 to 2026. The average salary went from $90,340 in 2017 per year to $92,800
in 2018, which represents a 2.7% increase. That is just about on par with the 2-3%
inflation number claimed by the BLS. The value
of benefits is not included. Alaska had the highest average pay at $128,69, while
Arkansas came in last with $71,730. On a side note, I've always been critical of
multistate companies having different pay scales for people doing the same jobs
at various locations. Sure, cost of living differs, but ultimately they are paying
employees unequally from a corporate accounting perspective.
"Chinese Amateur Satellite Group (CAMSAT)
has announced the impending launch of the CAS-7B satellite, also designated as BP-1B,
a short-lived spacecraft that will carry an Amateur Radio payload. An unusual feature
of the spacecraft is its 'sail ball' passive stabilization system. The 1.5-U CubeSat is
attached to a 500-millimeter flexible film ball - or sail - that will offer passive
'pneumatic resistance' stabilization. CAS-7B is expected to remain in orbit for
up to 1 month. The spacecraft will carry an Amateur Radio transponder and educational
mission. CAMSAT is working with Beijing Institute of Technology (BIT), a top aerospace
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In the light of having just marked the 75th
anniversary of the D-Day (Operation Overlord, June 6, 1944), which marked the beginning
of the end of Hitler's ruthless siege on all of Europe, please note how Electronics
magazine editor Lewis Young cites, in 1964, the continued rebuilding of Europe as
the reason many - maybe most - companies there are still, two decades later, concentrating
engineering and financial resources on getting back on a solid footing rather than
chasing after the latest and greatest in
nonessential technologies. It was probably an accurate assessment of the situation.
However, I do take issue with his admonishment to American companies to emulate
Europe's "practical approach" to innovation and manufacturing. There was absolutely
no reason to dissuade and throttle activity here ...
Custom MMIC, a leading designer and manufacturer
of high performance monolithic microwave integrated circuits (MMICs), has posted
a new blog entry entitled, "Advanced
MMICs Aid in Reducing Size and Power in Phased Array Radar Systems." Phased-array
radar systems are important instruments in national electronic defense strategies.
From the large, ship-based systems that scan for distantly launched missiles to
the more compact arrays installed on fighter aircraft and unmanned aerial vehicles
(UAVs), electronic phased-array radars come in many sizes and forms, providing reliable
signal detection and identification. These modern systems offer many advantages
over earlier radar ...
a plethora of special purpose calculators and units conversion resources available
online. As with most things on the Internet, you need to verify the accuracy of
results when using any of them for the first time. One units conversion website
I have used many times for swapping between SAE and metric units, and when needing
to find alternate forms of electrical units like volts/meter to Newtons/coulomb,
A nice feature is that the equivalent numerical values are instantly displayed for
all alternate units as well as for the new units you are seeking. I did not find
a furlong per fortnight unit for speed, though ;-) The site also
provides an assortment of calculators.
Ward Silver (N0AX) wrote a monthly column
for the ARRL's QST magazine for nearly decades before shifting over to
Nuts & Volts a couple years ago. Mr. Silver nowadays writes "The
Ham's Wireless Workbench," which as the title implies addresses the RF and microwave
aspect of electronics to complement the analog and digital aspects of the magazine.
In the March/April 2019 issue is an article entitled, "The Smith Chart," a subject that can make a grown
man cry upon initial introduction. Ward, in his inimitable style, helps make the
subject approachable. Only the first two pages (of six) are available online, so
you will need to either pay for full access or do as I do and get a copy from the
This was predicted, but it doesn't matter.
"It looked like a scene from a sci-fi blockbuster: an astronomer in the Netherlands
captured footage of a train of brightly-lit SpaceX satellites ascending through
the night sky this weekend, stunning space enthusiasts across the globe. But the
sight has also provoked an outcry among astronomers who say the constellation, which
so far consists of 60 broadband-beaming satellites but could one day grow to as
many as 12,000, may threaten our view of the cosmos and deal a blow to scientific
discovery. The launch was tracked around the world and it soon became clear that
the satellites were
visible to the naked eye: a new headache for
researchers who already have to find workarounds to deal with objects cluttering ..."
Anatech Electronics (AEI) manufactures and
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Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please
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Prior to phasing-based single sideband generation
circuits, a brute force filtering of the unwanted sideband and carrier signals was
required. Depending on how well the carrier was suppressed, more than half the total
signal power could be lost. According to author Jack Brown in this "Commercial
Aspects of Single-Sideband" article from a 1956 issue of Radio & Television
News magazine, it had only been since the mid 1940s that wide-band audio-frequency
phase-shift networks were even feasible. An ideal implementation of a single-sideband
suppressed-carrier modulator (SSB-SC) would result in 100% efficiency, but typical
results are in the 80% range ...
The Engineer website just posted the
results of its "The Engineer's 2019 Salary Survey." As you can
see, this is primarily an UK survey (understandable since The Engineer
is a UK entity), and the result shows, "a significant increase in engineering pay."
It reports by industry, not specific types of engineer; e.g, electrical, mechanical,
etc. Energy / renewables / nuclear is the top paying field at £58,695 ($74,377),
Telecoms & utilities / electronics fell in the middle at £51,825 ($65,711),
and academia came in last at £43,830 ($55,574). Those numbers do not incorporate
benefits and, in the case of academia, the value of job security in the form of
Since 1961, MECA Electronics
has designed and manufactured an extensive line of
RF & microwave components for in-building, satellite, radar,
radio, telemetry, mobile radio, aviation & ATC. Attenuators, directional &
hybrid couplers, isolators & circulators, power dividers & combiners, loads,
DC blocks, bias-Ts and adapters & cables. MECA has long been the 'backbone'
of high performance wired and air-interfaced networks such as in-building applications,
satellite communications, radar, radio communications, telemetry applications, mobile
radio, aviation & air traffic communications.
This is cool. I saw a U.S. Air Force recruitment
advertisement in a 1960 edition of Popular Electronics pitching careers as radar
operators (air traffic control) and technicians (maintenance). The picture has the
glide path and elevation sweeps from the MPN/13/14 radar system that I worked
on in the late 1970s - early 1980s. A photo I took circa 1980 of our unit based
at Robins AFB, Georgia, is shown below. The precision approach radar (PAR) operated
at x-band (10 GHz) with an operational range of 10 nautical miles. The azimuth
and elevation antennas were mechanically swept with motors that changed the geometry
of a waveguide having dipole stubs along its length. The entire PAR system ...
of Malvern, PA, manufactures an extensive line of N-way dividers / combiners (reactive &
resistive), high power combiners, directional couplers, 90° & 180° 3 dB
hybrids couplers, RF switches, phase shifters, limiters, detectors, bias Tees, and
DC blocks. Frequency ranges for products range from DC to 40 GHz, with CW power
handling to 500 W, depending on device.
"DARPA's Spectrum Collaboration Challenge
autonomous radios can manage spectrum better
than humans can. In the early 2000s, Bluetooth almost met an untimely end. The first
Bluetooth devices struggled to avoid interfering with Wi-Fi routers, a higher-powered,
more-established cohort on the radio spectrum, with which Bluetooth devices shared
frequencies. Bluetooth engineers eventually modified their standard - and saved
their wireless tech from early extinction - by developing frequency-hopping techniques
for Bluetooth devices, which shifted operation to unoccupied bands upon detecting
Wi-Fi signals. Frequency hopping is just one way to avoid interference, a problem ..."
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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 ...