When semiconductor junction devices - diodes
and transistors - first came on the electronics scene, many people were mystified
by their operation and had no idea how to work with them in terms of designing,
troubleshooting, or understanding circuit function. These
Mac's [Radio] Service Shop articles provided a great service to readers by always
addressing contemporary issues whether they be customer relations, new types of
radios and televisions, troubleshooting new kinds of circuits, shop procedures,
documentation interpretation, circuit operation, or as in this installment, test
equipment operation. As with so many things that appear in these vintage electronics
magazines, what was a big deal decades ago is commonplace now. The Kurz-Kasch Junction
Verifier described here is a cruder version ...
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 ...
Harrison, at NuWaves Engineering, has posted a short blog entry entitled, "The Benefits of
a Tunable RF Filter." NuWaves was founded by military veterans in the year 2000
and manufactures RF amplifiers and filters. Per Kevin's article, "Filters are a
staple of RF designers everywhere, and especially in applications where the integrity
of the signal cannot be compromised. When you're only concerned about a single frequency,
It's relatively easy to add in a fixed-tuned filter. However, it becomes slightly
more difficult when you need to cover multiple frequencies and can't just utilize
a roofing filter. To avoid having to use a bunch of individual filters, basically
creating a complex switched filter bank module, a tunable filter may be the solution.
One of the most common applications for a tunable filter is as a pre-selector in
a receive path ..."
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.
"China will provide unique services to global
users with the
Beidou Navigation Satellite System (BDS) after its construction is finished
in 2020, an official said Friday. Along with basic positioning, navigation and time
services, the BDS will provide six categories of special services that distinguish
it from other systems, said BDS spokesperson Ran Chengqi at a press conference.
The satellite-based augmentation system of the BDS will provide high-precision and
high-integrity services to users in civil aviation, maritime, railway and other
industries. In precise point positioning, the BDS will provide users in China and
surrounding areas with decimeter-level dynamic positioning and centimeter-level
static positioning, meeting ..."
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.
Television adoption immediately after World
War II in many of the European countries lagged the U.S., probably in no small
part due to a need to attend to the far more important task of rebuilding their
infrastructures and societies which were largely decimated by Hitler and his Axis
cohorts. This 1948 report in Radio-Craft magazine told of "televisors"
being mainly kits with few having displays larger than 2 to 4 inches (smaller than
most smartphone screens). 455 lines per frame was plenty for CRTs that small (NTSC
later standardized on 525 lines per frame). Another interesting item is how even
though Russia had been spared the ravages of one form of Marxism-Nazism-Socialism-Communism
from Germany, it chose to stay is course of the same (minus, maybe, Nazism) with
totalitarianism rule, to the extent that the article's author states, "If the authorities
decide that television is good for the soul of Ivan Ivanovitch, he'll have to be
keen on it, whether he likes it or not ...
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
Long before there were computer programs
to instantly plot antenna radiation patterns, there were engineers who used slide
rules to generate tables of values for power levels based on fundamental equations,
and then plotted those points by hand on graph paper. Any copies were either hand
generated like the original, or were run off on a mimeograph machine with its characteristic
purple ink. Such was the case for the antenna radiation patterns published in the
November 1942 edition of QST that describes the virtues of a
antenna in the UHF band. It is too bad that the author did not include the equations
for the antennas presented; that would really give you an appreciation for computers ...
Mr. Tim Galla has on the High Frequency
Electronics website a short article entitle, "RF
Low Noise Amplifier Technology Landscape Grows More Diverse," which summarizes
the evolution of semiconductor technology beginning with germanium and going through
the most recent carbon nanotube (CNT) research work. CNT is the wonder material
for many technologies both within and without electronics. The story begins, "RF
low noise amplifiers (LNAs) fabricated with solid state technology have been in
use for several decades. The early transition to solid state was pioneered with
germanium, has subsequently transitioned to silicon, and has now expanded to include
a wide range of compound III-V semiconductors and new carbon-based materials ..."
"Researchers in London have developed new
materials that could provide a low-cost option for converting heat into electricity.
Halide perovskites have been proposed as affordable alternatives to existing thermoelectric
materials, but research into their suitability for thermoelectric applications has
been limited. In this study, published in Nature Communications, scientists at from
Queen Mary University of London (QMUL) conducted experiments on thin films of the
halide perovskite - caesium tin iodide - to test its ability to produce electrical
current from heat. The researchers found they were able to improve the materials'
thermoelectric properties ..."
Axiom Test Equipment allows you to
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!
If you happen to be a retired
television repairman from the era of analog broadcast and cathode ray tube (CRT)
displays, or if you have studiously read the many articles I have posted from vintage
electronics magazines about TV, then you will probably breeze right through this
themed crossword puzzle from a 1958 issue of Radio & TV News. I have
to admit to having done poorly myself, even after having been the one who posted
all that stuff. Just having a general knowledge of electronics doesn't help much
here since all the clues and words are very specific to television circuits. Still,
it's worth the challenge and if nothing else you'll learn a little more about old
time television- it really was a quite ingenious scheme for cramming ...
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 ...
"Researchers in the U.S. have developed a
new coating that can
thermal radiation at some temperatures and could prevent detection by thermal
cameras. The ultrathin coating is made from samarium nickel oxide, a tunable material
that has some unique properties in certain temperature ranges. A general rule of
physics is that objects grow brighter as their temperature increases. This allows
infrared or thermal cameras to detect people and vehicles based on the heat they
emit. But the new coating does not exhibit this regular linear relationship with
heat and light and therefore has potential for camouflage devices or even clothing
to enhance personal privacy ..."
Vishwanath Tigadi has an interesting article
on the EDN website entitled, "Macro
Models Let Engineers Simulate Circuits & Systems." Mr. Tigadi suggests that
developing behavioral models that produce behavior in a simulation that closely
follows empirical measurements of actual components and/or systems. He begins: "Electronic
systems keep getting more complex. Much of the complexity comes from ICs, which
can undergo years of design and validation cycles before reaching the market. System
design engineering teams evaluate ICs before developing them into systems. IC Macro
models help system designers understand, simulate, and implement these devices into
systems before making any physical PCBs. Doing so cuts cost and time for the system
designers while protecting the design IPs of the IC design engineering units. This
article explains the need, benefit and market capturing aspects ..."
Standards and best practices for Web publishing
change seemingly on a daily basis. What was good yesterday is bad today. Prior to
the need for re-sizing images to accommodate responsive layouts for mobile devices,
that specifying height and width was done to give the browser knowledge of how much
space to reserve on the page so elements wouldn't shift around during page loading.
It also sped up the process. Now, most sizes are determined dynamically according
to space available (screen size). It slows things down, but that's the price you
pay. RF Cafe still specifies exact sizes, so that does not change. What has changed,
however, is no longer having off-site pages open in a new browser tab. There are
bad-guy exploitations that can happen in doing so. I have also eliminated some of
attributes since Google is changing the way they are handled. Happy 2020!
Centric RF is a company offering from stock
various RF and Microwave coaxial
components, including attenuators, adapters, cable assemblies, terminations,
power dividers, and more. We believe in offering high performance parts from stock
at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500
watts are available off the shelf. Order today, ship today! Centric RF is currently
looking for vendors to partner with them. Please visit Centric RF today.
Rudolf Engelbrecht, an alum of Oregon state
University, was inducted into the institution's Engineering Hall of Fame in 1998.
As evidenced in this full-page advertisement in a 1958 issue of Radio &
TV News magazine, Mr. Engelbrecht's work was instrumental in advancing
the state of the art in communications electronics while an engineer at Bell Labs.
Here, he is show with the four-stage
junction diode amplifier developed for military applications. It exploited the
variable capacitance nature of a varactor type diode to effect amplification in
the UHF and microwave bands. Engelbrecht went on to work at Radio Corporation of
America (RCA) later in his career. BTW, if you are wondering what other kind of
diode might there be other than a "junction" diode ...
Seamless integration of wireless communications
with wired communications has not always been a yawn in technical strategy discussions.
It has really only been since the early 1990s with the introduction of ubiquitous
cellphone systems that someone on a wireless device could connect directly with
a wired (i.e., landline) contact and not need an intermediary operator to facilitate.
military comms, the Inmarsat system and a few other proprietary systems were
available, but not to the public at large. This article reports on some of the Army's
early attempts at implementing wireless-to-wired communications, specifically as
implemented during the Normandy Invasion on D-Day. Unlike present day systems that
rely heavily on data compression and massive multiplexing, those systems allocated
the standard audio (voice) bandwidth ...
"Capella Space, an information services company
providing Earth observation data on demand, has announced that it will launch seven
synthetic aperture radar (SAR) satellites and start commercial operations in
2020. Powering this next step are Capella's breakthrough engineering technology
innovations that make it the first small satellite SAR company in the industry to
capture truly sub-0.5m very high-resolution (VHR) imagery. Capella's ultra-high
SAR captures more images per satellite relative to other small SAR satellites and
it has an ability to deliver SAR data to customers in less than 30 minutes from
the collection with real-time tasking ..."
article's title reads like one often found in the vintage electronics magazines
from which I scan and post here on RF Cafe. The full text of Ove Hach's "Resistors: Know How They
Drift," is on the EDN website. Unlike articles from many decades ago,
this one addresses resistor applications for high precision analog and digital circuits,
and includes a list of "ground rules" to apply when considering which resistor types
and tolerances to use. It begins, "The progress in digitization has profoundly changed
our lives. There is no area of everyday life to which digital circuits haven't penetrated.
Ever more powerful microcontrollers and data converters let you convert analog signals
into high resolution digital signals. What do you need to consider in selecting
the resistors for the upstream measurement amplifier? What possible errors ..."
RF Cafe visitor Rick Marz, KD6EFB, happened
upon my Erie Resistor Corporation webpage that is from a 1958 issue of Popular
Electronics magazine. As it turns out, Rick is a native of Erie, Pennsylvania,
and work at the company in the mid 1960s. He has since moved on to much bigger and
better things. Rick provided some very interesting historical information on his
Erie Technological Products - one incarnation of Erie Resistor - and how the
electronics industry evolved as he made the rounds of some of the top semiconductor
concerns of the era ...
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!
betatrons, cyclotrons, cosmotrons, synchrocyclotron, bevatrons, and other forms
of "trons" had the physics world all agog with anticipation of the next big discovery.
Quarks were still a decade away from being discovered and something as exotic as
the Higgs boson (aka god particle) hadn't entered anyone's mind. The news media
was agog with reports of the world possibly coming to the end as a result of those
experiments sparking a nuclear reaction chain that would cause the whole world to
explode. Today, the news media is no smarter, because nowadays they fret over the
Large Hadron Collider (LHC) generating a black hole that will implode the whole
Please take a few moments to visit the
everythingRF website to see how they can assist you with your
project. everythingRF is a product discovery platform for RF and microwave products
and services. They currently have 263,401 products from more than 1359 companies
across 312 categories in their database and enable engineers to search for them
using their customized parametric search tool. Amplifiers, test equipment, power
couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
You might already know this, but there is a method
for doing a Google search for webpages, documents, or images on only a specific
website. It is pretty much universal with all search engines. After entering your
search term, add a space and then site:<url> , where <url> is the address
of the website of interest. For example,
filter site:https://rfcafe.com returns all the instances of "filter"
on RF Cafe. To get a listing of all pages on the website, omit a specific topic
site:https://rfcafe.com . To view only the images from either example,
click on the "Images"
option on the search page.
IEEE Educational Activities Board (EAB) Awards recognize and honor individuals,
sections, and societies for major contributions in developing and delivering educational
products and services to IEEE members, professionals, educators, and students. Their
products and programs inspire understanding of IEEE's fields of interest, support
career preparation and professional enhancement, foster diversity, and ensure access
to lifelong learning opportunities. This year the EAB Awards Ceremony recognized
13 individuals, one section, and one society for their contributions to engineering
education. Award recipients were honored for their accomplishments in the areas
of pre-university and university education ..."
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.
engineering crossword puzzle features a special end-of-the decade message, comprised
of three words and clues, for RF Cafe visitors. As with my hundreds of previous
engineering and science-themed crossword puzzles, this one contains only clues and
terms associated with engineering, science, physical, astronomy, mathematics, chemistry,
etc., which I have built up over nearly two decades. Many new words and company
names have been added that had not even been created when I started in the year
2002. 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,