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4 of the March 2021 homepage
archives. Sunday the 21st
 This
Engineering-Theme Crossword Puzzle for March 21st has many words and clues related
to... you guessed it... engineering - including RF, microwave, optics, mathematics,
chemistry, physics, and other technical subjects. As always, this crossword contains
no names of politicians, mountain ranges, exotic foods or plants, movie stars, or
anything of the sort unless it/he/she is related to this puzzle's technology theme
(e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists
amongst us will appreciate the effort. Enjoy!
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
Friday the 19th
 Electric Tech (E-TECH) Construction, Inc. has
immediate opportunities for experienced RF Technicians with a wide range of
knowledge in Cell Site construction, modifications, new site builds, and 5G in the
Bay Area, market. We offer industry leading pay, paid time off, medical, dental,
and vision insurance, and 401k with match once eligible. Duties will include performing
all trades and duties associated with cellular / electrical construction, being
adaptable to learning new technologies, working in elevated areas in man lift, and
working varied shifts. Must be proficient at using industry testing equipment and
must be able to read and understand construction drawings. Anritsu certification
highly desirable along with previous / current tower climber experience...
 Occasionally an unbuilt vintage Heathkit
item appears on eBay with really nice photos of the contents. In fact, I have a
Saved Search that sends me an e-mail whenever one shows up. This morning, a
Heathkit
DG-140 Two-Station Intercom kit appeared on auction. The instruction booklet
has a publish date of 1972, so I looked for a copy of it on the WWW but the only
thing I could find was a PDF for purchase. Despite the 1972 date, it appears it
was 1973 when the DG-140 was first available. The 1971 catalog still shows the previous
version, the DG-141 (which you might understandably think would be the newer model
number). There is a big difference in the chassis configuration from the DG-141
to the DG-140. Per the 1973 Heathkit catalog, the DG-140 was priced at $29.95 ($184.91
in 2021 money - a whopping 6.2x factor in 48 years). Heathkit products were well
known for the completeness of its instruction manuals, with clearly illustrated
instructions...
 "According to researchers at Penn State,
micro-doppler radars could soon be used in clinical settings to
predict injury risk and track recovery progress. Being able to view subtle differences
in the human movement would allow health care workers to more accurately identify
individuals who may be at risk for injury and to track progress precisely while
individuals are recovering from an injury. To find an accurate, reliable, and cost-effective
way to measure these subtleties in human movement, the College of Engineering and
College of Medicine researchers teamed up to develop radar in front of which athlete
study-subjects could jump. 'My students and I designed and constructed the radar
system to characterize the micro-Doppler features of human gait..."
 Webster's dictionary defines luminescence
as, "the low-temperature emission of light produced especially by physiological
processes (as in the firefly), by chemical action, by friction, or by electrical
action." Per this article on electroluminescence in the November 1961 edition of
Popular Electronics, Webster defined it back then as, "any emission of
light not ascribable directly to incandescence, and therefore occurring at low temperatures."
Interesting that the contrast to incandescence is no longer used. Maybe in 1960
the phenomenon of
electroluminescence was still new and novel enough to emphasize the distinction.
Barely a decade had passed since it had moved out of the laboratory and into the
marketplace. The ability to economically produce large panels for lighting was deemed
groundbreaking...
 Berkeley Nucleonics Corporation, a leading
manufacturer of precision electronic instrumentation for RF/Microwave research,
introduces the
Model 685 High-Performance ARB. The function of an arbitrary waveform generator,
or ARB, varies depending on the application. Some of the many applications for a
waveform generator include timing solution, signal emulation and modulation of signals.
The Berkeley Nucleonics Model 685 High-Performance ARB offers a wide range of modulations
and pre-made waveforms as well as complex user-generated waveforms. The UI is intuitive
and easy to use through the touch screen interface but can also be used remotely
through software with commands or through a remote desktop using the standard Ethernet
interface. The Model 685 has two modes, AFG and AWG. The AFG (arbitrary function
generator) uses...
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Thursday the 18th
 According to an FCC document "11th Annual
Report, Federal Communications Commission, Fiscal Year Ended June 30, 1945," Chapter
VIII - War Activities, "The
Radio Intelligence Division, established in 1940 to give America wartime protection
from misuse of the ether lanes by spies or other illegal operators, discovered
46 unlicensed stations during the fiscal year, investigated 1,445 complaints of
suspicious transmission and of interference. These complaints were received from
the general public, commercial communication companies, Government agencies, and
the military. During the year, the RID furnished fixes to 283 planes which were
in distress. A total of 996 requests for assistance of all types to planes was received.
The RID took 85,031 bearings. A number of alerts originated totaled 25,000. This
figure represents the number of instances in which an origination was made by each
monitoring station equipped with long-range, high-frequency direction-finding facilities
for the purpose of obtaining synchronized bearings from a net of direction...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic
drawings! Every object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Symbols are provided
for equipment racks and test equipment, system block diagrams, conceptual drawings,
and schematics. Unlike previous versions, these are NOT Stencils, but instead are
all contained on tabbed pages within a single Visio document. That puts everything
in front of you in its full glory. Just copy and paste what you need on your drawing.
The file format is XML so everything plays nicely with Visio 2013 and later...
 "A team led by Technical University of Munich
(TUM) physicists Christoph Utschick and Prof. Rudolf Gross has succeeded in making
a coil with superconducting wires capable of transmitting power on the order of
more than
five kilowatts contactless and with only small losses. Conceivable
applications include autonomous industrial robots, medical equipment, vehicles and
even aircraft. Contactless power transmission has already established itself as
a key technology when it comes to charging small devices such as mobile telephones
and electric toothbrushes. Users would also like to see contactless charging made
available for larger electric machines such as industrial robots, medical equipment
and electric vehicles. Such devices could be placed on a charging station whenever
they are not in use. This would make it possible to effectively use even short idle
times to recharge their batteries..."
 Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized RF and microwave filters
and filter-related products for military, commercial, aerospace and defense, and
industrial applications up to 40 GHz.
Two new cavity filters have been introduced. The AB838B904 bandpass filter features
a 804.5-871.5 MHz passband with 1 dB insertion loss and can handle 50
watts. The AB2350B490 bandpass filter covers 2300 to 2400 MHz with 1.7 dB
insertion loss and handles up to 70 watts. Custom RF power directional coupler designs
can be designed and produced when a standard cannot be found, or the requirements
are such that a custom approach is necessary...
 Here is a crossword puzzle from the November
1957 edition of Popular Electronics magazine. Unlike the weekly crosswords
from RF Cafe that uses only relevant technical words, this one fills in with common
words. It's still a good puzzle and will take a lot less time to complete. A list
of all the other crossword puzzles found in Popular Electronics, Electronics
World, QST, and other vintage electronics magazines...
 Modelithics is pleased to announce the release
of new models for the Passive Plus R35-1209BB and R35-2010BB flip-chip resistor
products. New
Microwave Global Models™ for both resistor series are now available
within the Modelithics COMPLETE Library™ as well as the Modelithics mmWave &
5G Library. In addition, new 3D geometry models for the resistors are now available
within the latest version, v20.8, of the Modelithics COMPLETE+3D Library for Ansys®
HFSS™. The two new Microwave Global Models for the R35-1209BB and R35-2010BB resistor
families, respectively, for values of 50 and 100 Ω. Both models are validated
to 60 GHz, making them well suited for today's higher-frequency requirements...
 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.
Wednesday the 17th
 Not long ago I posted a short bit on the
1924
Montgomery Ward Radio Catalog I found on the WWW. It was the only
version of the actual catalog I could find. An advertisement for this 1939 edition
of the Montgomery Ward Radio Catalog appeared in a copy of Radio News magazine.
Like the earlier catalog, this one appeals to both professional servicemen and amateur
radio hobbyists - often one and the same. Mail order and brick and mortar outlets
like Radio Shack and Lafayette Radio Electronics (where I used to buy stuff in the
1970s) had not come to most of America's towns yet, so electronics enthusiasts often
procured their parts from Sears Roebuck, Montgomery Ward, and specialty catalogs
or from hardware and drug stores that happened to stock components. Of course you
could always walk into the local electronics repair shop...
 "How fast does data flow? The answer: not
fast enough. The search for more efficient data-transfer solutions to meet the ever-increasing
demand for computation never ends. Even today, most data transmission happens via
traditional copper cables, which are power-hungry, leading to a compromise between
data exchange and energy consumed. Fiber-optic cables are an alternative, but they don't work well
with the silicon chips in our computing systems. Overcoming these limitations, while
theoretically possible, can turn out to be prohibitively expensive, especially for
electronics-rich applications like data centers, spacecraft, electric vehicles and
so on. A team of scientists at the Massachusetts Institute of Technology have recently
demonstrated a plastic polymer cable that is a complementary solution..."
 Skyworks is pleased to introduce the
SKY67181-396LF, a high gain, low noise amplifier (LNA). Designed
to meet the challenging requirements of cellular LTE and 5G NR infrastructure applications,
this LNA features ultra low-noise figure, high gain, and operates over a wide range
of frequencies. Featuring an ultra-compact 2 x 2 mm plastic surface mount package
to reduce PCB board space, SKY67181-396LF is pin-to-pin compatible with the previously
released SKY67183-396LF and SKY67189-396LF. These LNAs are ideal for 2G/3G/4G/5G
TDD and FDD infrastructure applications, including small cell, massive MIMO, and
macro base stations...
 Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
 This is a great primer for anyone looking
for an easily understandable way to explain the basics of radio signal fading to
acquaintances, or for that matter to understand it yourself if you don't already.
As I review the material for taking my amateur radio General Class exam, there is
information about
atmospheric absorption in the various ionospheric layers during
daytime and nighttime. Prior to studying the manual, I either never knew or once
knew but have forgotten about the upper F1 and F2 layers combining into a single
layer at night when the sun's radiation and particle bombardment is blocked by the
earth. This article doesn't go that deep into the physics, but it does a good job
of making a complex topic simple enough for the layman - although if you're trying
to explain fading to politicians, well, don't even bother...
 RF Cafe visitor Zachary Fox sent me a note
regarding the "Basic Laser Experiments" article from the June 1971 issue of
Radio-Electronics magazine. Mr. Fox is an avid laser experimenter
/ hobbyist who has a blog on the
Laser Pointer Forum website where he documents his activities. He recently purchased
a document containing the actual photograph shown in the article that shows RCA
Solid State Research Laboratory scientist Dr. Karl G. Hernqvist projecting
the 24 spectral lines of a helium-selenium laser onto his hand. What was a big deal
in 1971 is ho-hum technology today, just like what is ground-breaking today will
be ho-hum in 50 years. We should be grateful for people like Zachary who collect
and preserve these parts of history so that someone with no interest doesn't throw
it out with the trash...
 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.
Tuesday the 16th
 Most people familiar with the history of
radio control (R/C) airplanes credit twin brothers Walt and Bill
Good for the first truly successful R/C airplane, which they dubbed "Big Guff,"
in 1938. Interestingly, this YouTube interview with the Good brothers mentions,
as does Mr. Isberg in his 1939 article in Radio News magazine article, the
first sanctioned R/C contest where the Good's model was the only one to fly. Ross
Hull and Clinton DeSoto were two other prominent early R/C'ers. Transmitter operators
were licensed Hams who designed and built their own equipment at 56 MHz, unlike
modern turn-key R/C systems operating in unlicensed ISM bands. Vacuum tubes were
used in the transmitter and the airborne receiver. Lead-acid batteries often provided
power for the receiver and control surface actuators (pseudo-servos) in the airplane,
which unfortunately would burst during a crash...
 "RF noise is a frequent discussion topic
among radio amateurs. A proliferation of electronics has cluttered and complicated
the noise environment; it's not just power lines anymore. Unless isolated from civilization,
most hams experience
RF interference (RFI) - sometimes without even realizing it, although
spectrum scopes on modern transceivers make RF noise much more apparent. Various
approaches to address the apparently worsening noise floor have been taken around
the world, some addressing lax regulation. 'We all want to enhance our ability to
copy the weak ones by increasing our signal-to-noise ratio,' Alan Higbie, K0AV,
said in his March/April NCJ article, 'Tracking RFI with an SDR One Source at a Time..."
 ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies for
amplitude and phased matched VNA applications as well as standard & precision
RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the
iBwave component library. They also provide custom coax solutions for applications
where some standard just won't do. A partnership with Newark assures fast, reliable
access. Please visit ConductRF today to see how they can help your project!
 Sending telegraph messages, whether by wire
or wireless means, has always been expensive, particularly considering charges are
determined by the character (letter, number, symbol). Accordingly, the Shakespearean
line from Hamlet declaring that "brevity is the soul of wit" can be reworked to
"brevity is the soul of economy." A telegraph wire, unlike a telephone call, is
a legally binding communiqué, as is of course a written letter, but a telegram is
immediate transmission of information for time-critical messaging. A series of "commercial codes" were developed enabling senders to save often
significant money by sending multi-character codes that represented entire phrases
and/or sentences. What struck me about this article that appeared in a 1948 issue
of The Saturday Evening Post is how, following a court case involving how the inadvertent
swapping of two character positions in a code...
 Mr. Kenneth Wyatt has a good article
on the EDN website entitled, "Pre-Compliance Testing Large Systems In-Situ." He gives advice
on relatively inexpensive tests you can perform on your new product design to help
assure first-pass EMC compliance testing as performed by commercial services - which
can be very expensive. He begins: "Last year, I had a chance to perform pre-compliance
testing on a couple large systems for radiated emissions. The clients were hoping
to get early test data prior to the major work of packing and transporting their
large floor-standing systems for formal compliance testing. Large industrial systems
need a whole different technique for assessing radiated emissions..."
 PCBONLINE supplies complex rigid and flex-rigid
printed circuit
boards (PCBs)，and one-stop production with maximum flexibility ranging from
prototype sample to mass production. Rigid-flex, HDI, multilayer, IC-loadboard,
LCP 5G optical module, ceramic, MCPCB. Materials include Rogers, Taconic, Arlon,
Isola, Bergquist, Kapton, Panasonic, and more. After more than 15 years of continuous
efforts, PCBONLINE constantly updates our equipment, improves our technology, and
serves you with the highest quality. Cost and delivery quotations online without
the need for multiple phone call and/or e-mails.
Monday the 15th
 Tracking down the source of TVI (television
interference) or any kind of RFI (radio frequency interference) can be a challenge. In the days
when most people received their audio and visual entertainment (radio and TV) via
over-the-air broadcasts, any form of interference was usually picked up by multiple
people, who promptly reported the issue to the power company or the FCC. Arcing
power lines, transformers, and switches were prime generators of RFI, particularly
during wet and high wind conditions. However, much more prevalent was interference
from industrial and domestic equipment. Neon and fluorescent light, heating pads
(see Hazel: Stop Rockin' Our Reception episode), ignition systems (automotive and
oil burners), diathermy (heat therapy popular in the day), industrial RF heating,
kitchen appliances, and tool motors were among the likeliest offenders. Of course
amateur radio operators were guilty of spewing out interfering EM crap...
 "Over the past few decades, the incredible
progress made in the electronics industry has been partially driven by innovations
at the single-transistor level. Building faster and smaller transistors has been
a primary goal for the semiconductor industry over the past few years. Metal-oxide-semiconductor
field-effect transistors (MOSFETs) are the most conventional and widely used type
of transistors. One of their major limitations is their high power inefficiency,
which is due to their inability to reduce the voltage supply while simultaneously
limiting the off-state leakage current. A novel and alternative type of device called
a
tunnel field-effect transistor (TFET) can overcome this limitation
by leveraging quantum mechanical tunneling..."
Free R&S Poster: Microwave &
Beyond
 Rhode & Schwarz (R&S) has just made
another great wall poster available, this one with the theme of "Microwaves and Beyond." As usual, the poster is full of colorful
charts and tables that provide lots of useful data at a glance. If you are used
to looking everything up on your tiny smartphone screen, you might be surprised
at how handy and easy on the eyes these old-school posters can be for a quick reference.
Signal level conversions, directivity and uncertainty, waveguide standards, RF connector
types, mismatch values, and electromagnetic spectrum bands are among the included
categories. You can either download a PDF version of the "Microwaves and Beyond" wall poster, or R&S will mail a "real"
version to you at no charge.
 Atenlab has been operating in Taiwan for
more than a decade, and has sold and installed hundreds chambers around the world.
Holistic, affordable Over-the-Air
(OTA) measurement systems perform comprehensive measurement and test in a controlled
environment. Compact Antenna Test Range (CATR) with one-touch operation supports
multiple systems - 2G, 3G, 4G, 5G - and major instrument brands. [M]ulti-probe OTA
measurement systems offer reduced time measurements over single-probe systems.
 It is hard to imagine a time when there wasn't
a vast network of highways connecting not just the interior of the continental U.S.,
but also interconnecting all of the countries in North America. Just as pioneers
in covered wagons and on horseback forged the routes that became the Oregon Trail
in the early 19th century, so did teams of explorers, cartographers and engineers
do the heavy lifting in the early 20th century in establishing the first defined
roads for expediting the transportation of goods and persons all up and down the
continent's west coast. Radio operators were among the crews of the
International Pacific Highway (IPH) project. Heavy, bulky, and
fragile tube-based radio equipment was transported in vehicles equally bereft of
adequate facilities in the form of power and shock absorbing suspensions. This story
from a 1931 edition of the ARRL's QST magazine tells of harrowing experiences in
the jungles and mountains of South America...
 Triad RF Systems, a leading designer and
manufacturer of innovative RF/Microwave amplifiers and integrated radio systems
for challenging environments, has posted a new blog entitled, "MANET: Why It's the Best Approach for Reliable Ad Hoc Networking."
It begins, "In our previous article, 'Overview: MANET (Mobile Ad Hoc Network),'
we explained MANET and its history, touched upon some of its major applications
and technological challenges, and described MIMO/MANET as one possible solution
to improve data communications, connectivity, situational awareness, and ability
to operate in A2/AD environments. This article will discuss MANET applications further
and explain why MANET is better than other technologies in these applications. The
military is one of the largest users of MANET. The military must perform a variety
of missions, often in a hostile environment. The Army, Navy, Marines, Air Force,
and Coast Guard require an information network between soldiers, vehicles, ships,
planes, and headquarters...
 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.
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
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