Electroluminescent (EL) devices were patented
by General Electric back in 1938, but it was not until the 1960s that the fabrication
process, involving copper-doped zinc sulfide (ZnS) as the light-emitting compound,
had developed to the point where high volume production was feasible. Early EL displays
exhibited short lifetimes and low efficiencies. EL panels are also referred to as
light-emitting capacitors because of their construction geometry. Some of the first
commercial applications for such EL panels were as back lighting in automobiles.
Electroluminescence can also be obtained in semiconductors in the III-V group class
like indium phosphide (InP), gallium arsenide (GaAs), and...
1945 or 2025? Seventy years have passed
since this photo of a
vacuum tube manufacturing facility in China was taken. Given that
most new vacuum tubes are made in China, and that the labor work conditions have
not changed much in the intervening time period (except in high-profile plants like
Foxconn where Apple products are made), this might very likely represent a modern
day operation. BTW, most of the vacuum tubes not being made in China are made in
Russia... to assure their antiquated infrastructure has an ample supple of replacement
parts. I say that only partly in jest. The largest market for new vacuum tubes is
music amplifier equipment and a few...
In that these
comics from Radio-Craft magazine have an electronics theme, you can
claim looking at them is work-related. The themes of the comics reflect common scenarios
of the 1944-1945 era in which they were published, but with not much modification
can be applied to today's environment. People will always expect more features from
products, will be critical of everything presented to them, and will want to haggle
for the best deal from the used camel salesman. You might consider using one of
them for your next conference or project status presentation. I missed the comic
on page 32 on the first posting of this page, but it's at the top now...
Sivers-IMA-Demonstrates-Next-Generation-Converters-2-27-2015.htm" >
Sivers IMA today announced that they are launching
the next generation converters for
E- and V-band radio links. The new generation converters are based
on the company's proprietary SiGe chip and offer a cost-effective and high-performance
solution for those who manufacture and market radio links. Sivers IMA's new converters
are designed to support very advanced modulation schemes, which enables capacities
of up to 10 Gbps. The products are developed for radio frequencies and applications
between 57 GHz to 86 GHz, the so-called V- and E-bands, and will be demonstrated
at the Sivers-IMA-Demonstrates-Next-Generation-Converters-2-27-2015.htm"...
By 1946, radio and television manufacturers
were scurrying to supply the huge, pent-up demand for
communications and entertainment systems that accumulated during
World War II. Fortunately, the dearth of electronics components, raw materials
for chassis fabrication, and available labor was suddenly and significantly turned
around by late 1945. Wanton destruction of entire cities in Europe left citizens
without many basic creature comfort items like radios, televisions, refrigerators,
vacuum cleaners, toasters, automobiles, and other things taken for granted a decade
earlier. As with any well-executed plan, manufacturers endeavored to survey the
market demand for such products and then devised...
If you ever have the opportunity to read the
history of the engineering efforts that went into designing and building the
Saturn V rocket, you will be amazed at the ingenuity and
incredible work that went into its creation. Margins of error approached single
digits in some instances, like with some of the fuel tanks. According to the book
NASA Apollo 11: Owner' Workshop Manual, re-design was constantly required
to remove weight from already-completed assemblies in order to compensate for overweight
components that could not be kept within their budget allocations. Some portions
of fuel tanks were so thin that a finger poke would deform the container. This news
item from a 1965 edition of Electronics World magazine reports on work...
everything RF, the leading online website for
the RF & microwave industry, has announced that they have now listed over 150,000
RF & microwave products
from the leading manufacturers. everything RF has developed a parametric search
technology which searches through multiple manufacturer catalogs to find products
based on specifications. Engineers no longer need to visit multiple manufacturer
websites to find products that meet their requirement. Users can compare products
across companies, download datasheets, get pricing and request quotations. RFQs
generated via everything RF everythingRF-Now-Lists-100000-Products-400-Manufacturers.htm"...
Advantage Electronic Product Development has announced
a position that is an ideal opportunity for an in-house PCB layout designer to contribute
their talents to projects that make a difference in people's lives. Includes a with
a wide range of board layout types in areas from RF to high-speed printed circuit
board layout. You will perform high-speed circuit board design, prepare PCB Design
layouts, create revisions, and/or CAD library symbols per verbal instructions. This
is an in-house position so if you live in Colorado, and can work full-time onsite
at our office in Broomfield, Colorado. Join a team of dedicated and extremely talented
individuals...
Make: More Electronics: Journey Deep Into the
World of Logic Chips, Amplifiers, Sensors, and Randomicity
(Learning by Discovery) is the most recent version
of Charles Platt's electronics tutorials. I looked through the reader comments on
a lot of the 'for Dummies' type books on electronics and this one by far received
the best ratings overall. Mr. Platt, a contributing editor and regular columnist
for Make magazine, has a few books
in the series and they all are loved by readers. "As a prototype designer, he created
semi-automated rapid cooling devices with medical applications, and air-deployable
equipment for first responders. He was the sole author of four mathematical-graphics
software packages, and has been fascinated by electronics since he put together
a telephone answering machine from a tape recorder and military-surplus relays at
age 15."
Once again I have given selflessly and freely
of my time and talent to make available resources to those seeking certain knowledge
regarding vintage radio circuits ;-) This time it is the Radio Service Data
Sheet for the
Majestic Model 25 - 9-Tube Twin-Detector and the
Howard Model 45 A. V. C. Superheterodyne with Model A. V. H. Chassis.
The info was published in a 1932 edition of Radio-Craft magazine, one of
Hugo Gernsback's many endeavors. Also on the pages is a complete list of all such
schematics and tuning and repair data posted thus far...
Fairview Microwave a global supplier of on-demand
microwave and RF components, releases new
RF circulators and isolators which are commonly used in radar
systems, wireless communications, DAS, test labs and amplifier systems where sensitive
RF equipment would require protection from reflected signals. Fairview Microwave's
2-port RF isolators are passive ferrite devices that aid in the protection of sensitive
RF components from excessive power reflection. Fairview's RF isolators are designed
with connectorized packages with SMA, Type-N, or 2.92 mm Fairview-Microwave-RF-Isolators-Circulators-2-24-2015.htm"...
Burying any antenna in the ground seems like
a bad idea from radiated field pattern and efficiency perspectives. As determined
in a 1974 paper published by the National Bureau of Standards, most of the energy
from a buried dipole antenna that is not absorbed by the ground is radiated nearly
straight up(many studies of underground antennas can be found).
Motivating the NBS's burial study was a desire to conceal radio communications antennas
in covert operations. This short piece in a 1935 edition of Short Wave Craft reports
on a case Hams were experimenting with buried antennas in order to avoid the expense
and trouble of an overhead installation. These days, Hams want to bury antennas
for those same reasons AND to get around restrictive neighborhood...
Model
2PA1000 is a new 2-way SMA power divider from Werbel Microwave
covering 2-18 GHz continuously in a compact package measuring 2 x 1 x 0.5 inches
with SMA female connectors. Low insertion loss, excellent balance and high isolation.
Great for lab testing environments. Each unit is hand-crafted with pride in the
United States Werbel-Microwave-2-18-GHz-SMA-Power-Divider-2-24-2015.htm"...
On his 65th birthday,
the inventor of the vacuum tube which made modern radio possible, looks back down
the years and comments: "I seldom tune in ... The programs, all swing and croon,
are not only poor, but the interruptions for commercial announcements are maddening
... Isn't it sickening? It isn't at all as I imagined it would be." -
Dr. Lee de Forest, in Time magazine, as reported in the February
1966 issue of Radio Craft magazine...
Beware of Those Bearing Advice
I'm not sure whether the irony was intentional
or not, but the first productivity tip I have linked here admonishes productivity
tip seekers to not just blindly accept productivity tips offered by self-proclaimed
productivity experts. In the two weeks since last posting links to
job
hunting and career improvement articles, there does not seem to be a whole lot
of good stuff out there. Maybe the severe winter freezing temperatures and unprecedented
levels of snow and ice has caused cabin fever and seasonal affective disorder to
concentrate more effort on personal survival than imparting their collective wisdom
to the ignorant masses...
Anatech 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. Anatech has released three new connectorized ceramic filter designs:
897/943 MHz duplexer with a 35 MHz bandwidth, a 915 MHz BPF with
a 15 MHz bandwidth, and a 1.88/1.96 GHz duplexer with a 60 MHz bandwidth.
All can be ordered through their
AMCrf web store.
Pulse compression (aka 'chirp') radar was
invented in the 1950s by Sperry and a couple other defense contractors. It was new
enough by the time the radar I worked on as a technician in the USAF that it was
not incorporated. Our MPN-13 and MPN-14 radar systems used simple single-frequency
pulses. Pulse compression employs a swept frequency within a fairly narrow bandwidth
to exploit the benefits outlined in this 1965 Electronics World article.
If you were to listen to the signal used to sweep the
RF pulse in frequency, it would sound a lot like a bird's chirp,
hence the name. Treatment by author Donald Lancaster is fairly heavy in that it
fearlessly presents the mathematical concepts of sin(x)/x waveforms, Fourier transforms,
and weighting. He references Skolnik...
Do you know what a "gimmick" is in the RF circuit world? If you have ever had the
occasion to repair or recondition inductors (coils, chokes, etc.), then you have
probably seen one and probably didn't know what it was. Read on to learn about a
gimmick capacitor. Working with the tiny wires on those old coils can be a real
challenge. Words you hadn't uttered in a long time tend to move to the forefront
of your memory in the process. Having struggled with a few multi-layered
RF coils from old radios, I am familiar with the intricacies of
trying to use fat fingers to wind and splice 40-gauge enameled wire in spaces 1/8-inch
wide. Many of those older coils are wound in thin, tall rings whose wires have a...
Skyworks introduces a > 0.5 to 4.0 GHz
LNA with an active bias, offering excellent return loss, low noise, and high linearity
performance for applications including high performance wireless infrastructure,
L and S band military radio, SDAR, DBS set-top box, and GPS. The
SKY67103-396LF features internal active bias circuitry which provides stable
performance over temperature and process variation. The device also offers the ability
to externally adjust supply current and gain. It is ideal for LTE, GSM, WCDMA, and
HSPDA macro base stations; small Skyworks-High-Linearity-Active-Bias-Ultra-Low-Noise-Amplifier-2-20-2015.htm"...
Always the consummate story teller,
John T. Frye began his writing career long before his "Carl & Jerry" electronics adventure series that ran monthly
for many years in Popular Electronics. His style featured creating a dialog
between instructor and student, serviceman and customer, husband and wife, father
and son, etc., in order to present an educational experience with back-and-forth
inquiry and responses. In the ended, the reader learns something about both sides
of of the situation. In this story, electronics service shop owner Mac reassures
technician Barney that given time and patience, he will grasp the circuit concepts
of the...
When this
Engineer's Survival
Kit appeared in my RF Cafe
Twitter feed, I though it was a gag item, but it turns out to be a very useful
experimenter's resource for mitigating EMI/RFI issues, provided at no cost by ARC
Technologies - at least for now. It comes with a variety of RF absorber materials
in different thicknesses and form factors that address frequencies from 50 MHz
through 110 GHz. The sheets of foam-based material are good, but what caught
my attention - and is the reason I bothered to post this promo - is the heat-shrink
tubing product. I have never seen EMI/RFI shielding in that format before...
Pasternack, a leading manufacturer and supplier
of RF, microwave and millimeter wave products, introduces new lines of
ultra-miniature UMCX, WMCX and HMCX32 coaxial cable assemblies.
These low profile, flexible micro-coax jumper cables offer operation from DC to
6 GHz and are ideal for wireless applications including Wi-Fi, Wireless LAN, Bluetooth,
ZigBee, LTE, mini-PCI, mobile antenna/GPS/radio systems, PDA/PCS/cellular handset
application and other wireless communications systems. These cables are commonly
Pasternack-Ultra-Miniature-Cable-Assemblies-6-GHz-2-19-2015.htm"...
Are you a
project builder? If so, then you probably make a point of reading
hints and tips offered by fellow aka do-it-yourselfers. Even with the ready availability
of just about anything you need already pre-manufactured, there are still times
that you either just want to figure out a better way of doing something or happen
to have a challenge that does not have a solution that can be purchased from a catalog
or on eBay. I have posted a few DIYer features from some of the vintage electronics
magazines, many of which are still relevant, or might at least give you an idea
for how to accomplish...
While perusing engineering and science magazines
and websites, I often run across photos of some
really cool-looking RF devices that make me wish I had a use for
them, or at least had examples to put on display as conversation pieces. Usually
the components look the way they do purely due to functional necessity, but sometimes
I think the designers intentionally add a little bit of 'wow' factor to them. Waveguide
components tend to dominate. Here are few examples of what I mean. The National
Electronics Museum, which often lends some of its items to the MTT-S show, has a
great collection of particularly nifty specimens. Sage Millimeter has this contraption
in one of their current magazine advertisements. I couldn't locate the exact item
on their...
Article of Interest
Wow,
it's been two weeks already since I last posted links to
engineering
magazine articles. This is not just a random selection of articles; I take a
quick look at them all and choose ones that seem like they will appeal to a large
cross-section of RF Cafe visitors, and/or articles that have a uniquely interesting
topic. Sometimes, just having a really cool picture will motivate inclusion, or
if I personally know the author. Nothing against the articles and authors that I...
-
RF Circuit Design References
(p 34), Peter Delos
-
Bluetooth and ZigBee: A New
Standards War Brewing?,
Cees Links
-
EM Filter Design Success:
The Fast Way,
James C. Rautio <more>
Rohde & Schwarz presents its new R&S NRPxxS
and R&S NRPxxSN USB three-path
diode power sensors. The completely redesigned sensors offer unprecedented
measurement speed and measurement accuracy, even at low levels. The R&S NRPxxSN
model offers both a USB and a LAN interface. Both power sensor models are available
for three different frequency ranges, from 10 MHz to 8 GHz, to 18 GHz
and to 33 GHz the largest choice of ranges on the market. Outstanding measurement
speed The R&S NRPxxS/SN sensors enable 10 000 triggered measurements per second
with a minimum trigger resolution of 100 µs Rohde-Schwarz-USB-LAN-Diode-Sensors-Power-Measurements-2-19-2015.htm"...
RFMW announces design and sales support for the 5SQ series of Tunable Inductors
from Frontier Electronics. The 5SQ series offers the highest Q in the industry
(Q=100 for the
5SQ-08). Low insertion loss minimizes roll-off near the
cut-off frequency in low-pass, high-pass and band-pass filter applications. Diplexer
designs benefit from the low insertion loss as well and experience very good stability
over temperature. Additional applications include tuner circuits and oscillators.
The 5SQ series tunable inductors have an impressive reliability history with zero
field failures among the 50 million RFMW-High-Q-Tunable-Inductors-2-12-2015.htm"...
Instrument Landing Systems
(ILS) has been around since the early 1930s, as made
apparent by this article in Short Wave Craft magazine. Frequencies, circuits,
and infrastructure equipment have evolved over the years, but fundamentally, landing
an aircraft (airplane, helicopter, dirigible) under
'blind' flying conditions has not changed. Two precision beams - one in elevation
and one in azimuth - broadcast by ground-based installations are detected by airborne
receivers and relative positions are displayed for the pilot's use in navigation.
ILS does not help the pilot fly the aircraft; it only leads him to the runway threshold.
In the past couple decades, space-based Global Positioning System
(GPS) equipment has increasingly been used to...
Hall devices are used not just for magnetic
field measurements, but also for for current and power measurements and as function
generators, transducers, multipliers, and isolators. The Hall effect comes into
play when a stationary current-carrying conductor is located in a magnetic
field, where electrons within the conductor are forced into a distribution that
favors one side of the conductor. The result is a difference of potential across
the conductor which is directly related to magnetic field strength by a well-defined
equation, permitting measurement of the magnetic field. A gaussmeter works on that
principle. Since a Hall device's output is proportional to the product of the control
current and the magnetic field, and the magnetic field determines the Hall voltage,
power can be...
Terahertz Metrology, by Mira Naftaly. This new book describes
modern terahertz (THz) systems and devices and presents
practical techniques for accurate measurement with an emphasis on evaluating uncertainties
and identifying sources of error. This is the first THz book on the market to address
measurement methodologies and issues - perfect for practitioners and aspiring practitioners
wishing to learn good measurement practice and avoid pitfalls. This book provides
a brief review of different THz systems and devices, followed by chapters detailing
the measurement issues encountered in using each of the main types of THz systems,
and a guide...
From keeping your son off the streets and out of pool rooms to learning the use
of his hands and mind for designing, building, and operating radio, John T. Frye,
later of "Carl & Jerry" authorship fame in
Popular Electronics magazine, offers up no less than eight good
reasons why a man should encourage his son (and/or daughter)
to take up amateur radio as a hobby - preferably one that will last a lifetime.
As is true with any activity that requires a person to exercise hand-eye coordination
and think logically about the order and method for best accomplishing a task, Ham
radio offers the complete gambit of life skills that should be nurtured at an early
age. In the same manner a musician benefits mightily from learning to read and play
music while the brain is still in the process...
This quiz is based on the information presented
in
Troubleshooting & Repairing Commercial Electrical Equipment,
by David Herres. The book provides a wealth of information on commonly encountered
electrical gear and identifies the kinds of problems most likely to be seen. Mr.
Herres recommends ways to help prevent the situations from occurring in the first
place as well as typical approaches for troubleshooting and repair used by seasoned
professionals. I have to admit that I had completely forgotten about the nickname
of "Wiggy" which has been bestowed upon one of my favorite electrical
test instruments...
X-COM Systems, LLC, a subsidiary of Bird Technologies,
today introduced the IQC91000A, the only
RF and microwave signal recording and playback system that can
capture, digitize, and store up to 1000 MHz of the electromagnetic spectrum in real
time without gaps and missed signal events within any frequency range from 500 MHz
to 18 GHz with 50 dB of spurious-free dynamic range, the highest in the industry.
The entire 1000-MHz signal capture file or selected portions of it can be regenerated
and played back at virtually any desired center frequency and offloaded at high
speed to a workstation for analysis. The IQC91000A is uniquely suited for signals"...
The last time I remember using
300-ohm twin-lead transmission cable for a television antenna
is about 20 years ago when I lived in a fairly rural area and had a VHF/UHF aerial
mounted on a 20-foot tower with a rotator. Since then the connections have always
been 75-ohm coax either to wired cable or a satellite dish
(now I have nothing). I do, however still have 300-ohm
twin-lead running from my ½-wave dipole antenna that is used for FM radio
reception. Most people more than 40 years old remember seeing the old tin lead running
down across the house roof, down the side, and through the living room wall. My
guess is that little consideration was given to cable routing and how it might affect
the performance of the cable. Twin-lead cable is amazingly low loss - typically...
"We are living in an extraordinary wired environment.
But all this technology cannot sustain itself unattended. The worldwide power grid
and connected equipment are like an enormously friendly and useful workhorse that
has to be fed and cared for if it is going to perform as expected" - David Herres,
in
The Electrician's Trade Demystified.
