 Friday the 5th
Thursday the 4th
Wednesday the 3rd
 About the
only kind of transmission line homeowners use today is 75 Ω coaxial cable
for television and Internet connections. Up until the turn of this new
century (two decades old by now - ugh!), a fair percentage of TV owners
still had an antenna mounted on the roof or maybe rabbit ears sitting atop
the set.
Twin lead transmission line was still a common sight as at least the
"last mile" (last few inches, actually) connection via an impedance
converter to the pair of screws on the back of a TV or FM radio. By then,
most TVs also had an "F" coaxial connector for direct attachment without a
converter. Internet connections at the time were telephone cords connected
to the modem board inside your computer. It's hard to believe that was
just a relatively few years ago that we early WWW users got to cross our
fingers when dialing up a local phone number for AOL, Earthlink,
Compuserve, Prodigy, Mindspring...
 "Even in the world of the smallest
particles with their own special rules, things
cannot proceed
infinitely fast. Physicists at the University of Bonn have now shown what
the speed limit is for complex quantum operations. The study also involved
scientists from MIT, the universities of Hamburg, Cologne and Padua, and the
Jülich Research Center. The results are important for the realization of quantum
computers, among other things. They are published in the prestigious journal
Physical Review X, and covered by the Physics Magazine of the American Physical
Society. Suppose you observe a waiter (the lockdown is already history) who
on New Year's Eve has to serve an entire tray of champagne glasses just a
few minutes before midnight. He rushes from guest to guest at top speed..."
 Safe-Com Wireless designs and manufactures
wireless communications equipment for first responders. The equipment comprises
boosters and fiber optic distributed antenna systems. The equipment is used
inside buildings to permit the first responder to communicate during emergence
incidents. The
Radio Frequency Test Technician / Associate Engineer position requires
minimum 5 - 15 years direct experience in RF board level testing using a spectrum
analyzer, radio frequency signal generators and similar radio frequency equipment.
The successful candidate will be experienced in reading circuit schematics,
troubleshooting circuits and documenting test results. Also hand soldering
and modification of surface and through-hole printed circuit boards (PCBs)
is required. Direct experience in a production work environment required...
 RCA's Numitron was their answer to
the Nixie tube (manufactured by Burroughs Corporation). It was a simpler 7-segment
incandescent display (DR2010) that, with all lines energized, formed the number
8. It worked off of +3.5 to +5 volts, with each element requiring 24 mA
of current. The number 8 drew 192 mA of current and dissipated 0.672 W
at 3.5 volts and a whopping 0.96 W at 5 volts! RCA marketed a BCD*-to-7-segment
display driver (the CD2501E). The
Numitron was pitched as a sensible alternative to the 7-segment LED display,
but with an element size of 0.35" wide by 0.6" high, there was no real advantage
over the LEDs, which were just entering the electronics market in 1970. Numitrons
do have a certain nostalgic 'cool' factor, though. It is interesting to note
that the author's last name, Wood, is the same as that of Frank Wood, who
was issued...
 Teledyne e2v HiRel Electronics, a leading
provider of high reliability semiconductor solutions, today announced a new
high reliability partnership with California-based Integra Technologies, Inc.
(Integra). Under the new agreement, Teledyne will leverage Integra's portfolio
of
GaN on SiC RF power transistor products to deliver optimized power solutions
for the space market. With Integra, Teledyne e2v HiRel will specialize in
providing high power RF devices for emerging space applications in the LEO
and GEO payload market. Teledyne will also offer high reliability options
for Integra's popular GaN on SiC power devices and pallets targeted at the
defense market. "Our space customers are requesting RF power devices at higher
power density levels and operating at higher frequencies," said Brad Little,
VP and General Manager of Teledyne e2v HiRel. "The combination of our expertise
in providing space...
 NextPCB is one of the most experienced
PCB manufacturers in China, has specialized in the PCB and assembly industry
for over 15 years. NextPCB provides the most innovative printed circuit boards
and assembly technologies in the highest quality standards, turnaround time
as fast as 24 hours, the lowest manufacturer direct prices, and the most dedicated
customer service in the industry. Turnkey service without a broker including
components sourcing, PCB prototyping, manufacturing, assembly, quality testing,
and final shipment. Certified by IATF16949, ISO9001, ISO14001, UL, CQC, RoHS
and REACH.
Tuesday the 2nd
 "The more things change, the more they
remain the same." That old saw has held true throughout the ages, but there
seems to be cycles within cycles that causes, to mix in a metaphor, the pendulum
to swing back and forth in greater and lesser peak amplitudes, and over long
periods of time a bias sets in that causes a perceivable change from the symmetric
tick-tock-tick-tock-tick-tock, to tick----tock-tick----tock-tick----tock-tick.
Without an outside-of-the-system input, the bias grows. If you have a "real"
gravity-driven pendulum clock, you probably know what I mean. Bringing the
system back to symmetry requires adjusting the clockworks movement or "righting"
the physical orientation by rotating the clock on the wall or shimming up
one side on the shelf until the preferred tick-tock-tick-tock is restored.
Economic cycles are much the same, as alluded to in this World War II,
War Bonds promotion. There are long periods of overall ups and overall
downs, and in-between there are lesser rises and falls. Eventually, those
who learn to control the cycles tend to insert a bias into the works...
 "Researchers have, for the first time
ever, demonstrated electrical control of
valley
transport in 3-D dual-gate diamond field-effect transistors. Not many people
are aware of it, but the diamond is actually a wide-bandgap semiconductor
with many extremely good properties, such as high thermal conductivity, high
breakdown field, high carrier mobilities, and chemical inertness. These properties,
together with the possibility to synthesize high-purity, single-crystalline
diamond make it a very interesting material and a candidate for use4 in power
electronics. The low impurity concentration achieved when fabricating diamond,
together with its rigid lattice, causes it to exhibit a uniquely low scattering
rate, especially at low temperatures..."
 The
Underwriter's Laboratory (UL) is an entity that seems to have been around
forever. A lot of people - maybe most people - assume that it is a government
entity. In fact, it is a non-profit organization sponsored by the National
Board of Fire Underwriters (later changed to American Insurance Association,
then to APCIA). Its roots are traceable back to the Chicago World's Fair in
1893. Concern over the potential fire hazard of Edison's light bulbs was the
impetus for the effort. Another aspect of the UL that a lot of people don't
know is that the UL label of approval is no guarantee that the device works
properly, only that is passes standards of safety as it relates to fire hazards.
This article in the August 1955 edition of Popular Electronics magazine
gives a brief history.
 RF Cafe visitor Tommy Reed sent me
this link to a blog he recently posted on FromDCtoDaylight.com (great name)
website entitled, "17
Best RTL-SDR Software Defined Radio Dongles." About six months ago I bought
the Nooelec NESDR Smart v4 bundle to use with a modification I'm making to
a couple vintage 72/75 MHz radio control systems. The 3rd-party interface
and processing software is OK, but could be better. Otherwise, it works quite
well. Says Tommy: "Software Defined Radios (SDRs) are become more and more
popular. This is partially due to the wide availability of low cost USB dongle
SDR radios based on RTL2832U demodulator chipset. This is where the 'RTL'
in RTL-SDR comes from. While these low cost SDRs are not as capable as some
of the higher performance SDR radios, they do offer a good bang for the buck.
In this post we'll take a look at 17 great RTL-SDR dongles..."
 Modelithics is honored to announce
that it has crossed another milestone in the history of the company. As of
March 1, 2021
Modelithics,, will be celebrating 20 years of establishment. What began
as a small spinout startup from the University of South Florida has risen
to stand tall as the industry leader in RF, microwave and millimeter-wave
measurements and measurement-based modeling of RF and microwave components
and semiconductor devices. We are proud of our company's many innovative products,
custom service projects, designer focused application notes and other accomplishments
that have proven to be exceptionally productive for our customers...
 This assortment of custom-designed
themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee
Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly
clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow
Chart." My "Matchmaker's" design has been ripped off by other people and used
on their products, so please be sure to purchase only official RF Cafe gear.
My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your
purchase price. These would make excellent gifts for husbands, wives, kids,
significant others, and for handing out at company events or as rewards for
excellent service. It's a great way to help support RF Cafe. Thanks...
 Copper Mountain Technologies develops
innovative and robust RF test and measurement solutions for engineers all
over the world. Copper Mountain's extensive line of unique form factor
Vector Network
Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement
hardware via USB interface. The result is a lower cost, faster, more effective
test process that fits into the modern workspace in lab, production, field
and secure testing environments.
Monday the 1st
 With most solid state devices, be they
discrete elements or integrated circuits, discerning their functions by visual
inspection is nearly always impossible. A trained observer can use a microscope
on a bare die to get a good idea of what the various parts do. Memory banks,
transistors, resistors, capacitors, etc., are usually pretty obvious even
to someone relatively new at the job. Opaque overmolded packages and/or extremely
small features complicate the task. In the
vacuum tube days, anyone accustomed to working with them could fairly
easily look at the the arrangement of heaters, cathodes, grids, and plates
- sometimes singular but often multiple - and figure out the function. Experts
could even make a fair guess at the key electrical specifications. Of course
that only applied to those with clear glass envelopes. Tubes with special
shapes might have been a bit more difficult to guess the application. To wit,
the long, skinny R-1110 "Pirani Tube" shown here is an example. It is designed
to measure ambient pressure...
 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.
 "The Perseverance rover's
Mars Helicopter (Ingenuity) will take off, navigate, and land on Mars
without human intervention. Tucked under the belly of the Perseverance rover
that will be landing on Mars in just a few days is a little helicopter called
Ingenuity. Its body is the size of a box of tissues, slung underneath a pair
of 1.2m carbon fiber rotors on top of four spindly legs. It weighs just 1.8kg,
but the importance of its mission is massive. If everything goes according
to plan, Ingenuity will become the first aircraft to fly on Mars. In order
for this to work, Ingenuity has to survive frigid temperatures, manage merciless
power constraints, and attempt a series of 90 second flights while separated
from Earth by 10 light minutes. Which means that real-time communication..."
 It had been only a little over a decade
since the transistor was invented when this article appeared in the August
1959 edition of Popular Electronics. Transistors were still a mystery
to most people, including engineers, technicians, and hobbyists. Author James
Butterfield takes a unique approach in presenting the material by writing
it as a dialog between an instructor and a student. If you are also
new to transistors, this will be worth your while to read. The basics
will never change. As an aside (and mentioned in the article), while still
a technician I had a manager one time who actually told an engineer working
for him that a transistor could be made by soldering two diodes together and
using the center node as the base connection...
 KR Electronics, a designer and manufacturer
of high quality filters for the commercial and military markets for more than
45 years, introduces the model
3450 lumped element bandpass filter with a 1,000 MHz center frequency
and a 1 dB bandwidth of 50 MHz (~975 - 1025 MHz). The filter
is a highly selective elliptic type filter. The filter is supplied either
with SMA connectors (0.60" x 0.60" x 2.25" not including connectors) or in
a surface mount package. Other frequencies and bandwidths are available...
 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.
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RfCaFe
autodidacts
Electronics-Themed
Comics June 1951 Radio-Electronics
 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. I also re-broadcast homepage items on LinkedIn. If you need
your company news to be seen, RF Cafe is the place to be.
Advertising begins at $40/month.
 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!
 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 (click
here for screen capture). 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...
 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...
This assortment of custom-designed
themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee
Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly
clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow
Chart." My "Matchmaker's" design has been ripped off by other people and used
on their products, so please be sure to purchase only official RF Cafe gear.
My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your
purchase price. These would make excellent gifts for husbands, wives, kids,
significant others, and for handing out at company events or as rewards for
excellent service. It's a great way to help support RF Cafe. Thanks...
 RF
Cafe's raison d'être is and always has been to provide useful, quality content
for engineers, technicians, engineering managers, students, and hobbyists.
Part of that mission is offering to post applicable
job openings. HR department
employees and/or managers of hiring companies are welcome to submit opportunities
for posting at no charge. 3rd party recruiters and temp agencies are not included
so as to assure a high quality of listings. Please read through the easy procedure
to benefit from RF Cafe's high quality visitors...
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 "Research could lead to the development
of new materials with large
magnetoelectric (ME) coupling for next-generation multifunctional devices,
including, multi-state (neuromorphic-like) circuits and memories, and E-field
tunable microwave resonators for secure communications. Multifunctional magnetoelectric
materials with high exchange represent a missing 'holy grail' of materials
physics. To combine polarization and magnetization in the same solid is nothing
short of actually controlling the fundamental nature of electromagnetism in
matter. Although magneto-electricity (ME) is an intrinsic phenomenon in some
natural materials at low temperature, such single-phase materials suffer from
an extremely weak ME exchange..."
 "The team from the Intelligent Vehicles
Group at Warwick University published its study in the IEEE Sensors Journal,
which details how the researchers specifically simulated and evaluated the
performance of
LiDAR sensors in the rain. High-level autonomous vehicles (AVs) are promised
by Original Equipment Manufacturers (OEMs) and technology companies to improve
road safety as well as bringing economical and societal benefits. All high-level
AVs rely heavily on sensors to operate. Using the WMG 3xD simulator, researchers
tested an autonomous vehicle's LiDAR sensors in different intensities of rain..."
 "Electrical and Electronic Equipment
(EEE) has become indispensable in modern societies and is enhancing living
standards, but its production and usage can be resource-demanding. After its
use, EEE is disposed of, generating an
e-waste stream that contains hazardous and valuable materials. EEE includes
a wide range of products with circuitry or electrical components with a power
or battery supply, according to The Global E-Waste Monitor, a report produced
annually by United Nations University and other international organizations..."
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