Today in Science History -
Life is a constant
battle on all fronts, be it in health, personal relationships, business,
medicine, careers, education, technology, or any other realm. Scientists,
engineers, and technicians at the former
Bell Telephone Laboratories are affected by that maxim as well as any group
of people. The company, known to many as Bell Labs, invested a huge amount of
funds and personnel effort into fighting the problems which constantly cropped
up both during research and development and while servicing their massive
installed base of equipment and transmission lines. Bell Labs regularly ran
full-page ads in magazines (including technical and others like Life, The
Saturday Evening Post, Woman's Day, etc.) informing the paying public of the
extents they went to in order to bring new products to market and to keep
existing systems providing excellent quality communications (the best in the
world). This example for a 1948 issue of Radio News magazine tells of the
unexpected chemistry issues solved by their crack teams of employees...
Center of Telecommunication Technologies
(CTT) is proud to announce immediate availability of its
RadioPlanner v1.0 software. Indoor RadioPlanner is a planning tool for Wi-Fi
and other indoor wireless networks. Release 1.0 is mainly intended for planning
Wi-Fi networks in the 2.4 GHz, 5 GHz, and 6 GHz bands, but it can
be used for planning indoor GSM/ 3G / LTE / 5G networks in the frequency range 300 MHz
– 7.5 GHz. With Indoor RadioPlanner, you can design Wi-Fi networks of any scale
- from a small office to a large multi-story building...
Berkeley Nucleonics recently added a couple
of courses on
Quantum Computing in the Berkeley Nucleonics Academy. Because you have taken
previous RF courses with 100% completion, you are entitled to those QC courses at
no charge. Would you like a passcode? You may also share this code with any colleagues
or students who may have an interest. Completion of the course takes approximately
4 hours and includes CEU units, a Completion Certificate and a BNC "60 Years" Commemorative
Tee-Shirt. The Nuts and Bolts (and Qubits) of Quantum Computing: This exclusive
course will dive into the immersive world of quantum computing. Take quizzes, watch
videos and get current knowledge of quantum computing from experts in the industry.
QC 02 - Quantum Computing Instrumentation in Use Today" A cursory look at some of
the research and development tools...
Selenium rectifiers were the first widely
used replacements for vacuum tubes in commercial electronic equipment. Since amplification
was not possible - that came in late 1948 with the invention of the transistor,
compliments of Shockley, Brattain and Bardeen - diode action in AC-DC power supplies
was its primary application. Typical reverse breakdown voltage is in the neighborhood
of 20 volts and current handling capability depends on the interface surface area.
Cost kept the selenium rectifiers from being widely adapted early in their history
(1933), but by 1946 when this article was published in Radio-News magazine
it had dropped enough to make their use economical. Eliminating one or two vacuum
tubes in a radio or television power supply made the sets more efficient and increased
reliability since the selenium rectifiers rarely suffered failures if designed into
the circuit correctly...
Amentum is seeking a motivated
Junior RF Engineer
in Hanover, MD, willing to dive into the world of satellite communication coordination.
Job Summary: We are looking for an engineer with the curiosity to work problems
until truly understood and then the drive to identify and implement efficiencies
in the problem-solving process. You have a foundation in radio frequency (RF) engineer
principles to apply that knowledge in the RF analysis of new and existing satellite
systems being proposed. Responsibilities will include analysis and certification
for emerging spectrum dependent technologies, review of new satellite network submissions,
and evaluation of RF related interactions between satellites. Beyond the analytical,
you'll also need to communicate highly technical findings to a large international
stake holder community. You will be part of a team evaluating the risk to Department
of Defense (DoD) assets...
Well I'll be darned, old Mac the master
radio repairman taught me something else new in this October 1949 issue of Radio &
Television News magazine. Along with giving sidekick and trusted technician
Barney a lesson on business ethics and how honest dealing can pay dividends as societal
conditions change, he also put on his Sherlock Holmes cap and deduced a
surprising cause for circuit failure based on the physical location of a lady's
radio; read on to learn the details. As usual, the exact scenarios of the stories
do not apply to today's environment and/or equipment, but the troubleshooting logic
certainly does. And, as usual, the time of year wherein the technodrama takes place
aligns with the edition's month of publication...
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite of engineers,
technicians, hobbyists, and students all over the world. With more than 12,000 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.
Alliance Test Equipment 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.
Alliance Test will purchase your excess test equipment in large or small lots. Blog
posts offer advice on application and use of a wide range of test equipment. Please
visit Allied Test Equipment today to see how they can help your project.
Antenova Ltd, the UK-based manufacturer
of antennas and RF modules for M2M and the IoT, is launching GNSSNOVA M20071, a
GNSS receiver module, with power consumption reduced five-fold to enable smaller
tracker designs, and trackers that run for five times longer. The M20071 module
is for small tracking devices that operate from Li-ion batteries, where a lower
power requirement is a clear advantage. These are typically small mobile trackers,
pet trackers, personal fitness devices, and location trackers for bikes and e-scooters.
The M20071 tracks the GPS, Galileo, GLONASS and BeiDou constellations simultaneously,
this improves position accuracy particularly in urban environments. Based on the
latest generation chip from Mediatek, it draws 17 mW of power when receiving GPS
only, and 21 mW receiving all constellations. GNSSNOVA M20071 measures 9.0 mm x
9.0 x 1.8 mm. Pairing this with one of Antenova's compact SMD antennas makes a compact
RF solution and a way to realise slimmed down tracker...
I have to admit to not being real certain
why I selected this article on
feedback tone control for posting. It appeared in the December 1958 issue of
Hugo Gernsback's Radio−Electronics magazine. Although it is a good write-up
on some simple audio frequency filtering circuits, and the principles can be applied
to any frequency, it is most likely this page was marked because it contained an
electronic-themed comic on it. Oh well, Melanie already scanned and OCRed it for
me, so you might as well go ahead and read it...
"The quest to transmit electric power wirelessly
and over distance has been a goal of electrical engineers since the end of the 19th
century, when Nikola Tesla tried his hand at it, to no avail. In the 1970s, NASA
and the U.S. Department of Energy engineers achieved some notable successes in
wireless power transfer
(WPT) in the kilowatt-kilometer range, their efforts spurred on by the energy crises
of the time. Interest waned, however, as energy became plentiful again. Now, with
the advent of 5G and its ability to transmit at high frequencies in the millimeter-wave-band
range, new opportunities and approaches are opening up for WPT. Researchers at the
Tokyo Institute of Technology have developed a prototype 64-element millimeter-wave-band
phased-array transceiver that can send and receive data while simultaneously receiving
power. The aim is to employ the transceiver initially as a 5G relay, and later to
integrate into Internet of Things (IoT) devices..."
TotalTemp Technologies offers two new ways
to elevate your testing with our thermal testing products. Beyond the normal ways
Thermal Platforms and Chambers help you get the job done expeditiously, TotalTemp
is offering: Thermal test equipment with Cloud Storage technology and also Outer
Space Simulation chambers. Supporting the effort to get product testing done correctly,
repeatedly with consistently reported results, Synergy Server and available cloud
storage technologies let you have your test data quickly and easily organized, with
traceability. The days of circle-chart recorders and hand plots are long gone, your
test results can be reliably automatically stored. The efficient advantages of thermal
platforms are a natural for conductive heat transfer in high vacuum applications.
With all the new hardware going into space, where service calls are rare, thermal
vacuum testing is important part of testing high altitude and satellite equipment...
Here's a topic -
filter design - that never goes out of style. It was originally published in
a 1952 issue of QST magazine. Without bothering to worry about source and
load impedances, this brief tutorial on the fundamentals of power supply filter
design using series inductors and parallel capacitor combinations. Author Gabriel
Rumble offers a rule-of-thumb type formula for guessing at a good inductor value
based on peak-to-average expected current. This is by no means a comprehensive primer
on power supply filter design and is directed more toward someone new to the concept
of removing or reducing noise and AC ripple from the output of a DC power supply...
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...
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
component supplier. RF coaxial connectors & adapters, coaxial cable &
cable assemblies, surge protectors, attenuators. Items added daily. Free shipping
on orders over $25. We're leading the way again!
I really like the electronics themed comic
that appeared on page 36 of the June 1952 issue of Radio-Electronics magazine. Like
with this one, many of the ideas for the comics are provided by readers, and then
are incorporated by artists such as Frank Beaven, a frequent contributor. Note in
that comic the name of the repair shop is the first name of the guy who submitted
it - a sort of hat-tip to the guy. As with many of the comics, I have taken the
liberty of colorizing them in order to spice them up a bit. The page 78 comic represents
the frustration (and annoyance) a lot of in-home electronics servicemen had to endure
from customers who desperately want their help, but then wouldn't leave them alone
to do their jobs - and then often tried to cheat them out of the pay they earned...
Manmade electrical noise (QRM) and natural
electrical noise (QRN) has been the nemesis of communications - both wired and wireless
- since the first signals were sent. While it is true that over the last century
the amount of "background" noise has increased significantly, the ability of modern
circuits to deal with (reject) it and/or accommodate (error correction) it has pretty
much kept up with the advancement. You might be tempted to think that "back in the
good old days" such problems did not exist, but operators were plagued by poorly
designed and inadequately filtered transmitters as well as really deficient electrical
service installation that spewed noise from transformers, inadequately grounded
transmission lines, lousy connections, and arcing motor brushes. This 1930 article
from Radio-Craft magazine was written by a serviceman who troubleshot and
solved many of the issues prevalent in his day - a very interesting read...
"Scientists at the University of Rostock,
in close collaboration with partners from the Vienna University of Technology, have
developed a novel process that can
render artificial materials transparent or even entirely invisible, on demand.
Their discovery was recently published in the renowned journal Science Advances.
Turning something invisible is a common trope in science fiction, such as the Cloak
of Invisibility in Harry Potter. Certainly, it sounds cool, but the reason it is
so common in stories is that it would be incredibly useful technology. The uses
for espionage and the military are obvious, but there are far more applications.
Given its immense usefulness, it may not come as a surprise that this is something
scientists and engineers have been actively working on. They've had quite a bit
of progress too, using molybdenum trioxide, metamaterials, metascreens, and dielectric
materials to fashion invisibility cloaks. It all comes down to manipulating light
in the proper way, and what is especially marvelous is that innovation in this
Empower RF Systems is a global leader in
power amplifier solutions. Empower RF Systems is an established and technologically
superior supplier of high power solid state RF & microwave amplifiers. Our offerings
include modules, intelligent rack-mount amplifiers, and multi-function RF Power
Amplifier solutions to 6 GHz in broadband and band specific designs. Output
power combinations range from tens of watts to multi-kilowatts. Unprecedented size,
weight and power reduction of our amplifiers is superior to anything in the market
at similar frequencies and power levels.
Center of Telecommunication Technologies
(CTT) is proud to announce immediate availability of version 2.0 of their popular
Antenna Pattern Editor.
Antenna Pattern Editor 2.0 is a universal tool to view, create, edit and convert
antenna patterns. See the New Features in Antenna Pattern Editor 2.0 list at the
left. The main idea embedded in the program is to provide the user with the opportunity
to quickly create an antenna pattern file using various methods. Antenna pattern
file is a simple text or xml file that describes the main characteristics of the
antennas - radiation patterns, gain, frequency range, name, manufacturer and other
data. These files are used in various radio planning tools including our RadioPlanner,
Indoor Radio Planner, and MLinkPlanner. There are a large number of antenna pattern
file formats, but it often happens that there is no file in the required format.
In this case, using the Antenna Pattern Editor, you can easily convert the file
to the format you need. Sometimes the antenna information is just a picture of the
reactance measuring bridge circuit which appeared in a 1931 issue of Radio−Craft
magazine employs a very unique element for generating an alternating current: an
electromechanical buzzer which doubles as an audio source. Sure, it doesn't produce
a pure sinewave, but for the method used here to determine inductance and capacitance
it does not matter. Rather than attempting to measure an absolute value of inductance
or capacitance, a known reactance is used as part of a balanced bridge. This is
by no means a precision instrument since accuracy depends on the user's interpretation
of the presence or absence of an audible "buzz" in a pair of headphones, but in
an era when "real" test equipment was beyond the budgets of many (maybe most) hobbyists,
the scheme was better than nothing at all...
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
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...
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
In no way do I advocate going back to the
"old ways" for manufacturing electronic components, but I do admire and like to
give credit to the people who used to perform the tedious procedure of
vacuum tubes, hand-wire chassis assemblies, circuit boards, etc. This 1932 issue
of Radio−Craft magazine article is good example. The process required being
able to sit or stand at the same work station and perform the same range of operations
day after day, often for years on end. Of course at the time, automation processes
were not what they are today and machinery needed to be driven by mechanical means
using motors, solenoids, and limit switches. That made employing people more financially
rewarding than using a machine. You can find details on the algorithms and methodology
for designing those contraptions in older engineering handbooks. It is an amazing
sight to to tour a WWII vintage battleship and look at the hardware that stabilized
and steered the cannons without an electronic computer in sight...
"Researchers have discovered a
single-molecule switch that can act like a transistor and store binary information
such as the 1s and 0s used in classical computing. The molecule is around five square
nanometers in size - more than one billion of them would fit onto the cross-section
of a human hair. The researchers believe that molecules like the ones they have
discovered could offer information density of around 250 terabits per square inch,
which is around 100 times the storage density of current hard drives. The smart
molecular switches as seen with a scanning tunneling microscope. In the study, molecules
of an organic salt can be switched using a small electrical input to appear either
bright or dark, providing binary information. This information can be written, read,
and erased at room temperature and in normal air pressures. These are important
characteristics for practical application of the molecules in computing storage
There was a time when having a career in
any field of
electricity or electronics related work was an enviable mark of a person's technical
prowess that conveyed a degree of respect. The whole controlling of electrons thing
boggled the minds of most people, whether it meant wiring homes and buildings for
lights, receptacles, and motors, or designing "all wave" radio sets for listening
to the evening broadcast of "The Lone Ranger." Today, with nearly everyone alive
having grown up with such conveniences, the "wow factor" is pretty much gone, except
maybe with those of us who still chose to engage. If an electronics appliance or
device stops working nowadays, it is discarded rather than repaired. This 2-page
advertisement from a 1946 edition of Radio News magazine inviting men to
become a "bonded electronic technician" is typical of those found in the era, and
even in the 1920s and 1930s...