Friday 22
Just as most people no longer wear a wristwatch
since their (practically) surgically attached smartphones can provide the time,
few people bother with carrying around an electronic calculator. It's' been that
way for at least a decade now. When this article entitled "Calculators
Get Smaller, Smarter and Cheaper" appeared in a 1974 issue of Popular Mechanics
magazine, pocket electronic calculators were still a relatively new phenomenon. Hewlett
Packard had introduced their first calculator, the HP−35, just two years earlier.
The first American-made pocket calculator, the Bowmar 910B, aka "The Brain," came
out in late 1971/early 1972 and sold for about $240. It had only basic math functions
and sported a tiny LED display. Prices fell very quickly as many companies were
releasing models with more and more features. By the time of this article, calculators
with basic functions could be bought for a mere $16.95 ($84.05 in 2019 money ...
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 7,000 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, Facebook, and Twitter. If you need your
company news to be seen, RF Cafe is the place to be. Banner advertising begins
at $175/month ...
Triad RF, located in East Brunswick, NJ,
is a leader in the design and manufacture of RF SSPAs and Systems. An
Applications Engineer is needed to support our customers and provide them with
pre-sales technical support on our products. Tasks include working with customers
and recommending suitable products based on their radio link and system requirements.
The applications engineer will also work with Sales Administrators and assist them
in the preparation of customer quotes. The applications engineer will also work
with the test lab in establishing design test standards based on customer requirements.
Skills and qualification include: Understanding of basic electronics concepts such
as NPN transistors, MOSFETS, TTL logic, supply voltage, current draw, power added
efficiency, knowledge of amplifier-related concepts such as gain, power output,
power compression, linearity ...
This is a repeat of something I posted a decade
ago, but by now millions more people have entered the electronics realm and might
appreciate it. You might, too, if you didn't see it originally. You have probably
seen somewhere along the line in your electronics career the resistor cube problem. The
12 edges of the cube each contain a 1 Ω resistor, and the challenge is to calculate
what the equivalent resistance is between two opposing corners. It is a daunting
problem using straight circuit analysis, since it requires writing and solving multiple
mesh equations. There are lots of opportunities for making mistakes. One option
if you had the time and facilities would be to build the model in a circuit simulator
and let it determine the result. Usually, though, the cube is thrust upon you in
a compromising situation, like in a job interview ...
"The
latest International Amateur Radio Union Region 1 Monitoring System (IARUMS) newsletter
reports the
Russian "Contayner" over-the-horizon radar
(OTHR) has been active in the 7, 10, 14, and 18 MHz amateur radio allocations
(amateur radio is primary on 40, 20, and 17 meters). The OTHR transmissions have
been 40 sweeps/second, FM on pulse, and 12 kHz wide. Additionally, IARUMS reports
a significant increase in Russian military traffic using F1B, PSK, and orthogonal
frequency division multiplex (OFDM) on 40, 30, 20, and 15 meters. IARUMS on November
13 reported an OTHR in northern Iran on 6.078 – 7.022 MHz, AM on pulse, 81
sweeps/second, 44 kHz wide."
Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today!
Thursday 21
The year was 1941 and the radio industry
was going strong worldwide. Sales of receivers was hitting new highs every quarter
and service shops had all the work they could handle for repair, upgrades, and installations.
The radio broadcast realm was scrambling to build new studios, install transmitters
and antennas, hire announcers and managers, and upgrade to keep up with the quickly
evolving business. Take a look at these 24 full pages of
radio-related products offered by the Sears, Roebuck Company in their Fall and
Winter 1941-1942 catalog. It is typical of most radio manufacturers' catalogs of
the era. For the last decade engineers had been working overtime to satisfy consumer
demand for fancier cabinet designs with fancier features. So strong was public demand
that people put their highest priority on acquiring the latest models (not unlike
the smartphone craze of today). Then, ...
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 (of course
a gratuity will be graciously accepted). 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 ...
The
RCA Victor Model C9-4 is a 9-tube, 3-band superheterodyne console model radio
made in the mid 1930s. A Radio Service Data Sheet for it appeared in the January
1936 issue of Radio-Craft magazine. The image of the radio was found on
the RadioMuseum.org website. FM broadcasting was not in common use yet, so only
AM bands and some shortwave bands were available. In fact, 1936 was the year that
frequency modulation (FM) inventor Edwin H. Armstrong first demonstrated his
newfangled concept that largely solved the electrical static noise problem cause
by lightning, motor brushes, arcing overhead power lines ...
This High Density Switched Reluctance Motor (HDSRM)
designed by Newcastle University's Advanced Electric Machines (AEM) could be a serious
game changer to the electric vehicle industry if it proves viable. The 6-phase motor
does not use permanent magnets or copper conductors, and claims to be competitive
in performance with the current crop of motors that need rare earth magnets and
copper wire. That represents major advantages in lower cost and independence from
rare earth magnets, which now come primarily from China. Be sure to watch the video.
Jolly good show, chaps!
ThinkRF Corporation, the leader in software-defined
spectrum analysis, today announced the release of the
PyRF3 Development Framework with support for version 3.0 of the Python Language
Application Programming Interface (API). This latest API enables command, control
and data acquisition using ThinkRF Real-Time Spectrum Analyzer platforms, including
the ThinkRF R55x0 and R57x0 analyzers. The updated version ensures RF application
developers can leverage the PyRF Development Framework to build custom solutions,
integrate new capabilities, and develop or extend products quickly and easily. PyRF
is a freely available, comprehensive development environment for wireless
signal analysis, built on the Python Programming Language ...
Res-Net Microwave has a complete line of
precision RF & microwave components including attenuators,
terminations, resistors, and diode detectors for commercial, military, and space
applications. Products range from the small flange type to large 2,000 watt connectorized
power attenuators and/or terminations at frequencies up to 26.5 GHz. In-house
photo etch and laser trim capability. The company is a leader in development and
production of the films required for these type of RF/microwave components. Please
check out Res-Net Microwave's website to see how they can help with your current
project.
Wednesday 20
In 1958, most people were not accustomed
to seeing the now-familiar maps plotting the sinusoidal courses of satellites across
the face of the earth. It had only been in October of the previous year that any
object other than the moon was in orbit around our home planet - that was U.S.S.R.'s
Sputnik. Just as people of all ages and all backgrounds enthusiastically joined
in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their
fragile craft at Kitty Hawk, electronics communications and scientists worldwide
hopped aboard the satellite train (so to speak). This article from a 1958 issue
of Radio & TV News magazine provided insight into the construction
and flight characteristics of
early U.S. satellites, and offered advice on how to participate in the ongoing
International Geophysical Year (IGY) research effort by tuning in and reporting
your signal reception characteristics. Activity was not just the domain of operators
with sophisticated equipment ...
Sam Benzacar of Anatech Electronics, an RF
and microwave filter company, has published his November newsletter that features
his short op−ed entitled "Is
5G Safe for Humans? No One Knows." The controversy over whether or not RF radiation
from wireless devices - cellphones, notebook computers, tablets, smart meters, et
al, is harmful to human body cells has been with us since the early 1990s, when
the Wireless Revolution began. Industry standards groups have defined Specific Absorption
Rate (SAR) levels for exposure that model human anatomy and cell structure in order
to scientifically assess the effects of RF radiation. As with studies done with
other controversial topics like tobacco and pharmaceuticals, the "truth" is as much
subjective as it is objective, and the two side of the argument will never agree ...
This quiz from Popular Electronics
magazine challenges (not too much, though) your knowledge of
energy conversion in common devices. A few of them might be unfamiliar to people
born after about 1990, but even so, you've probably seem them all at some point,
especially if you are a regular RF Cafe visitor (meaning you're probably smart).
It won't be giving anything away by telling you that item B is a heater that screws
into a light bulb socket, and item F is a phonograph stylus Robert P. Balin
constructed many quizzes of this kind in the 1960s and 70s. A complete list of all
the Popular Electronics Quizzes is lower on this page ...
Axiom Test Equipment, an electronic test equipment
rentals and sales company headquartered in San Diego, has published a blog post
entitled "Turn
on the Temperature with Thermal Test Systems," explaining the need to properly
evaluate product function across the full range of expected ambient temperature
conditions. Doing so helps guarantee favorable customer experiences and online ratings,
as well as reduces costs of warranty service. It begins: "Electronic device performance
is sensitive to temperature, with most electronic devices and components specified
according to operating and storage temperature ranges. Those ranges differ according
to the type of component and application, with electronic products for industrial
and military applications usually ..."
"Electromagnetic
interference (EMI) can plague
bus bars just like it does with cables.
Here are the answers to some common questions. Do bus bars need EMI filters? Yes,
they do. Just because they're large imposing structures, they can cause interference
in other systems if you don't measure the EMI and take steps to get it under legal
limits. In some cases, you might want to reduce EMI even further than the legal
requirement to make a quiet electrical environment for your sensors or control system.
EMI noise is created by any fast-changing currents, often represented by the calculus
term di/dt, that is, the change of current over time. Fast-changing currents have
high di/dt. If those currents ..."
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.
Tuesday 19
Proving once again what a visionary Hugo
Gernsback was regarding science and engineering, he published in his Radio-Craft
magazine this prognostication for the eventual supplanting of point-to-point wiring
with
printed circuit boards. Admittedly, by 1948 the electronics industry had begun
to outgrow hand-wired chassis assemblies with a rats nest of wires, components,
and terminal strips. It was in dire need of a new paradigm that reduced labor costs
and reduced the opportunity for wiring errors. Less than a year earlier (December
1947) the trio of engineers at Bell Labs announced their transistor invention, so
Mr. Gernsback knew the world was about to change significantly. Bulky transformers,
vacuum tubes, and high voltage circuits would soon be relegated - at least in the
consumer product realm - to the newfangled television products, so miniaturization
would follow quickly. Even the smaller fingers of women on the assembly lines ...
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 (of course
a gratuity will be graciously accepted). 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 ...
Skyworks is pleased introduce the SKY66318-11,
a new addition to our family of high-efficiency power amplifiers (PA) that are designed
for the stringent requirements of enterprise small cell applications. The PA offers
wide instantaneous bandwidth (100 MHz) and is fully input/output matched with
high gain and efficiency. On-chip active biasing circuitry is also integrated to
compensate for PA performance over temperature, voltage, and process variations.
The device comes in a compact 5 x 5 mm package, operates from a single 5 V
power supply, and is ideal for 4G LTE and 5G NR systems from 3300 to 3600 MHz.
The SKY66318-11 is also part of major transceiver reference designs ...
Here is a little electronics hobbyist humor
in the form of a comic series titled "Hobnobbing with Harbaugh," compliments of
Popular Electronics artist Dave Harbaugh. Citizens Band radio and dirty
hippies were the topic of the day in the 1970s, so that's what you see in a couple
of these comics. I got my first 23-channel CB radio (FCC mandated 40 channels in
1977) in 1976 and installed it in my 1969 Camaro SS hot rod. It required a
Class D radio operator license at the time, but shortly thereafter no license
was needed. The "Inventions Wanted" comic is my favorite, followed by "Mayday...
Mayday!" You don't need to be an amateur radio operator to appreciate these comic
strips ...
"Satellites do a lot of things - they help
people navigate from one place to another, they deliver television programming,
they search for new stars and exo-planets and they enable the U.S. nuclear deterrence
strategy. But until recently, one thing they haven't done - or needed to do - is
defend themselves. That may soon change. Researchers at Sandia National Laboratories
launched a seven-year mission campaign this month to develop the science, technology
and architecture needed for autonomous
satellite protection systems. The campaign,
called STARCS (Science and Technology Advancing Resilience for Contested Space),
will fund dozens of Laboratory Directed Research and Development projects that focus
on three critical areas ..."
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!
Monday 18
Forgive me if I sound like a broken record
(a scratched record, actually), but when selecting articles for posting here on
RF Cafe, I like to include ones that are directed toward newcomers to the field
of electronics as well as for seasoned veterans. This piece from a 1958 issue
of Radio & TV News magazine entitled "Basic
Electronic Counting," is a prime example in that it introduces the concept of
binary numbers. We've all been there at some point in our careers. A big difference
between now and when this article appeared is that in 1958, almost nobody was familiar
to binary numbers, and fuggetabout [sic] octal and hexadecimal. Only those relatively
few people designing and working with multimillion dollar, vacuum tube-based digital
computers installed in universities, megacorporations, and government research facilities ...
"The
2020 Cubesat Developers Workshop will
be held May 4 - 6 at the Cal Poly Performing Arts Center in San Luis Obispo, California.
The planning team has announced a call for abstracts. All abstract and poster applications
should be submitted using the online submission form on the conference website by
Friday, January 10, 2020."
Exodus Advanced Communications' model
AMP2070C power amplifier designed for broadband EMI/RFI, lab, communications
and EW applications. Class A/AB linear design for all modulations and industry standards.
Covers 700 MHz - 6.0 GHz, produces 100 W minimum, 50 W P1dB,
50 dB gain. Excellent gain flatness, optional monitoring parameters for forward
/ reflected power, voltage, current and temperature sensing for superb reliability
and ruggedness. Suitable for CW, pulse and all single channel modulation standards
Built-in protection circuits ...
Radio Service Data Sheets were published
by various electronics trade magazines back in the early to middle decades of the
last century. SAMS Photofact document sets were published on just about every appliance
made, and those had much more detail than these briefs. However, for the low-budget
repair shop or the do-it-yourselfer, the Radio Service Data Sheets were a godsend.
I have been scanning, cleaning up, and posting all the ones I find in my vintage
electronics magazine collection. See a complete list at the bottom. Many fine examples
of restored vintage radios can be found on the Internet. A restored example of the
RCA Victor Model 102 s appears on the RadioMuseum.com website ...
"Circuits made from thread are combined with
thread-based sensors to create flexible
devices. A transistor has been made from linen thread, enabling the creation of
electronic devices made entirely of thin threads that could be woven into fabric,
worn on the skin, or implanted surgically for diagnostic monitoring. The flexible
electronic devices could enable a range of applications that conform to different
shapes and allow free movement without compromising function. The thread-based transistors
(TBTs) can be made into all-thread-based logic circuits and integrated circuits.
The circuits replace the last remaining rigid component of many current flexible
devices and when combined with thread-based sensors, enable the creation of completely
flexible ..."
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.
Sunday 17
For two decades, 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. This November 17,
2019, puzzle uses a database of thousands of words which I have 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 ...
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