Tuesday the 14th
May 1946, when this
Atomic Medicine article appeared in Popular Science magazine, was less
than a year since the atomic bombs that ended World War II were dropped on
Hiroshima and Nagasaki, Japan. The Manhattan Project, codename for the U.S. effort
that led to both the fission and fusion bombs, was necessarily shrouded in secrecy
in order to assure that Germany's Uranverein work did not benefit from America's
success. Once the horrific destructive power and effects of radiation exposure were
witnessed by the world, even more importance was placed on keeping the lid on nuclear
technology. During the post-war era, getting information on radio and radar advancements,
material science, aircraft and rocket propulsions and aerodynamics, emergency medical
devices and formulations, and other realms of high technology was difficult, but
the government would divulge almost nothing on nuclear research. The media collectively
had fits over it all, claiming the public that sacrificed life, limb, and fortune
had a right to access and benefit from at least some of the information. The editor
of Popular Science magazine published a full−page op−ed...
Anatech Electronics 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. Three new
filters have been announced for November 2023: a 15,350 to 15,750 MHz
(15.350 to 15.750 GHz) cavity bandpass filter with an insertion loss of 1.0 dB,
a 15,125 MHz (15.125 GHz) cavity bandpass filter with a bandwidth of 400 MHz,
and a 8750.55 MHz cavity bandpass filter with a ripple of ±0.05 dB over
a 25 MHz passband. Custom RF power filter and directional couplers designs
can be designed and produced with required connector types when a standard cannot
be found, or the requirements are such that a custom approach is necessary...
This is the third and final installment
of Hy Levy's series on
attenuators, line filters, and matching transformers as published in Radio−Craft
magazine. Audio and low IF frequencies are used in the examples, but the formulas
and principles can be extended to higher frequencies. Bifilar windings are covered
as a method of minimizing self-inductance in wire-wound resistors. Although inductance
is not desired in resistors, bifilar windings can also be connected to have current
in both wires flowing in the same direction, thereby increasing the magnetic field
rather than canceling it. You will probably want to read the previous two parts
to work up to this point...
"Chinese
scientists have produced a chip that is significantly faster and more energy efficient
than current
high-performance AI chips when it comes to performing some tasks such as image
recognition and autonomous driving, according to a new study. Although the new chip
cannot immediately replace those used in devices such as computers or smartphones,
it may soon be used in wearable devices such as computers or smartphones, it may
soon be used in wearable devices, electric cars or smart factories and help boost
China's competitiveness in the mass application of artificial intelligence, researchers
wrote in a paper published in the journal Nature. The country is scrambling to catch
up in the AI race with the United States after Washington introduced a series of
curbs on China's access to technology, including advanced chips... "
In the early days of radio, it was common
for manufacturers to sell the electronics chassis separately from the cabinet, as
well as selling a chassis / cabinet combination. Even as late as in 1941, the Crosley
03BC radio I have was a custom wooden console sold for accepting electronics from
the 02CA electronics. I have never been able to find an advertisement where Crosley
sold the 03CB as an integrated set, although I have seen ads for the cabinet. This
Crosley Model 1316 chassis was evidently supplied in an optional Model 167 console
cabinet, as presented in a 1936 issue of Radio−Craft magazine. A Web search
turned up other Model 167 cabinets of both the "tombstone" and "cathedral" design.
Did the Crosley numbering system top out at 167 for a while?
RF Cascade Workbook 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...
RIGOL Technologies is transforming the Test
and Measurement Industry. Our premium line of products includes digital and mixed
signal oscilloscopes, spectrum analyzers, function / arbitrary waveform generators,
programmable power supplies and loads, digital multimeters, data acquisition systems,
and application software. Our test solutions combine uncompromised product performance,
quality, and advanced product features; all delivered at extremely attractive price
points. This combination provides our customers with unprecedented value for their
investment, reduces their overall cost of test, and helps speed time to completion
of their designs or projects.
Monday the 13th
Here are a couple electronics circuit analysis
problems to prime you for the week ahead. They are from the August 1964 "What's
Your EQ?" challenge in Radio−Electronics magazine. EQ, by the way,
is for Electronics Quotient, as in IQ (Intelligence Quotient). Some others are in
the list below. In the Autotransformer problem, I made the assumption that the secondary
tap was actually in the middle (as drawn), so that there was an equal number of
turns above and below the tap. That proved to be a good assumption since it validated
my answer (not difficult if you know the basics of autotransformers). The other
problem, "Case of the Lost Energy," is a variation on similar ones containing a
potentially (pun intended) non-intuitive missing energy being stored in capacitors.
I'll admit to not having worked through it yet. You'll probably figure it out in
no time...
Innovative Power Products leads the RF industry
with reliable, high power hybrid couplers ranging from HF to X band. The new
IPP−7153 90-degree SMD hybrid coupler handles 100 W CW of RF power in the
full 6 to 12 GHz band despite a size of only 0.25" x 0.20" x 0.07". The IPP−7153
has less than 0.40 dB insertion loss, greater than 16 dB isolation, and return
loss of less than 1.40:1. It offers exceptional amplitude and phase balance for
matching, at ±0.70dB and ±6 degrees, respectively. IPP-7153 Detailed Product Specifications:
Visit our IPP-7153 product page to download mechanical drawing PDF, view typical
test data, and for s-parameters. IPP also offers a variety single ended transformers,
baluns and our patented impedance transforming couplers..
This is a different type of Radio Service
Data Sheet in that rather than presenting a schematic and service data on a particular
piece of electronic equipment, it provides a table of "The
First 10 Metal Tubes" introduced to the industry. As reported in other articles
I have posted from the mid-1930s era magazines, the advent of vacuum tubes that
used a metal envelope rather than the typical glass envelope was pitched as the
most significant advancement in electronics since the invention of the amplifier
tube itself (Lee de Forest's Audion) in 1906. In fact, much of this October
1935 edition of Radio-Craft is dedicated to doting over the metal tube...
QuinStar is excited to announce a groundbreaking
addition to our product lineup – the
Microwave/Millimeter Wave (MMW) Electronically Controlled Attenuator Unit, setting
a new standard in wireless communication technology. This state-of-the-art unit
is designed to provide unparalleled performance, offering superior coverage from
K-Band to D-Bands and showcasing remarkable attenuation linearity exceeding 80 dB
dynamic range and higher. Our MMW Electronically Controlled Unit covers an extensive
frequency range, spanning from K-Band to D-Band, making it a versatile and adaptive
solution for a myriad of applications across various industries. Equipped with both
Ethernet and USB 2.0 interface ports. Impressively, this new design showcases attenuation
exceeding 80 dB, significantly enhancing the unit's ability to manage and control
the signal, ensuring exceptional clarity and precision in communication. With a
typical attenuator step size of 0.02 dB, this unit allows precise and fine-grained
adjustments, enabling optimal signal control tailored to specific needs...
At first I was going to comment that using
a wizard in an astrologer's robe to promote chemistry (alchemy, in particular) as
an example of a career option does not seem like a good choice for appealing to
serious prospects. However, given the weirdness of a good portion of the population,
it might be as effective today as it evidently was nearly a century ago when the
Chemical Institute of New York ran this ad in Radio-Craft magazine.
Dr. T. O'Conor Sloane, reputed head of the Institute, published such tomes as The
Standard Electrical Dictionary, How to Become a Successful Electrician, Arithmetic
of Electricity, Electricity Simplified, Electric Toy Making for Amateurs, Fortunes
in Formulas, and numerous others. BTW, I learned from the ad that the word "adept"
is a noun as well as an adjective. Per Merriam-Webster: "a highly skilled or well-trained
person." As a noun, the accent is on the first syllable; as an adjective it is on
the second. Accordingly, an a'·dept is a·dept' at a particular skill...
Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your Banner Ads are displayed on average 280,000 times per year! 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. If you need your company news to be seen, RF Cafe is the
place to be...
The
Wireless Telecom Group,
comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer
of advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
Sunday the 12th
This week's crossword puzzle for November
12th sports an electronics theme. This being the twelfth day of the month, many
of the words begin and/or end with and/or contain the letter "L" (denoted by an
asterisk). All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger,
and have only words and clues related to RF, microwave, and mm-wave engineering,
optics, mathematics, chemistry, physics, and other technical subjects. As always,
this crossword contains no names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort unless it/he/she is related to this
puzzle's technology theme (e.g., Reginald Denny, Hedy Lamarr, or the Tunguska event
in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We
Are the World's Matchmakers" Smith chart design. These would make excellent
gifts for husbands, wives, kids, significant others, and for handing out at company
events or as rewards for excellent service. My graphic has been ripped off by other
people and used on their products, so please be sure to purchase only official RF
Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press.
It's a great way to help support RF Cafe. Thanks...
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.
Friday the 10th
This
is my annual
Veterans Day tribute. On November 11 (the 11th day of the 11th
month), at 11:00 am (the 11th hour), we observe two minutes of silence in honor
of countrymen who "gave the last full measure of devotion." A Pittance of Time
is performed by Canadian citizen Terry Kelly (he
went blind at an early age). It was written after an experience he had in a store
on Veterans Day in 1999. The piece is done in the finest Celtic tradition. In regard
to the Communist and Fascist regimes where life and limb was sacrificed, have we
thus far won the battles, but lots the war? Look around you.
Imagine how much it must have tortured Thomas
Edison to find out he had been the first to discover
thermionic electron flow, the basis for all future vacuum tube technology, and
did not recognize it at the time. As reported in this 1947 issue of Popular Science
magazine, Mr. Edison made his finding in 1883 while investigating designs for
electric light bulbs. Ambrose Fleming recognized the significance of the phenomenon
in 1904 when he built the world's first diode tube. Three years later, Dr. Lee
de Forest inserted a modulating grid between the cathode and anode and, voila,
the amplifier tube was born (the audion). Edison died in 1931 with the knowledge
that his fame and fortune resulting from his electric light bulb, talking machine
(phonograph), moving pictures, stock ticker, multiplex telegraph, storage battery,
fluorescent lighting, Portland cement, and multitudinous other inventions could
all have been trumped by the missed discovery of the diode and triode. You might
be tempted to think he probably was content with his credited accomplishment, but
that's not the way genius overachievers work.
"The European Space Agency (ESA) has once
again pushed the envelope of technological innovation by
3D printing electromagnetic coils in pure copper, a leap forward in the design
of versatile tools essential for a myriad of space missions. This breakthrough comes
as a result of one of the over 2,000 research contracts completed under ESA's General
Support Technology Programme (GSTP), an initiative that has been collaborating with
European industry and academia for the past thirty years to refine technologies
for space exploration and commercial markets. The unique electromagnetic coils,
which play a critical role in the function of electric motors, magnetic bearings,
and magnetorquers utilized for satellite attitude control, have been crafted using
a sophisticated end-to-end process. This process is rooted in laser powder bed fusion
3D printing and was developed for ESA by Zarm Technik in Germany. As the GSTP celebrates
its 30th anniversary, it is worth noting that the program commenced in 1993 as part
of ESA's forward-looking strategy to stay at the forefront of necessary spaceflight
technologies. Over time, it has become a pivotal component of ESA's broader technological
initiatives..."
Axiom Test Equipment, an electronic test
equipment rental and sales company has published a new blog post entitled "Surveying
EV and HEV Power Testing Solutions" that covers how tunable power sources and
wide-dynamic-range analyzers can examine electric power systems of EVs/HEVs. As
more drivers adopt EVs and HEVs, they wonder about maintenance costs and routines
compared to traditional motor vehicles with internal-combustion engines. HV battery
systems in EVs and HEVs are among these vehicles' most important components since
the greatest driving ranges are reached at their fullest charge capacities. They
must be regularly tested to ascertain their status and capacities as part of a regular
EV or HEV maintenance routine. Battery systems can be evaluated through voltage
and power measurements, but additional test procedures can be helpful in monitoring
the performance levels of these many additional "supporting" electronic components
in EVs and HEVs...
This is the
electronics market prediction for Russia, circa 1966. It was part of a comprehensive
assessment by the editors of Electronics magazine of the state of commercial,
military, and consumer electronics at the end of 1965. Then, as now, Russian electronics
products are not considered to be serious competition to U.S. markets. For that
matter, when is the last product of any type you bought with a "Made in Russia"
stamp on it? Even though the Soviet Iron Curtain fell in 1992, very little progress
has been made with mending fences with them. Unless you can find a news story on
the state of the industry, detailed reports must be purchased from research companies
like Statista. Their website has a lot of charts on Russia's current electronics
market showing revenue in the consumer electronics segment amounts of US$2,942M
in 2018...
The United States Marine Corps (USMC) was
officially formed on November 10, 1775 as the Continental Marines. The famous line
"From the Halls of Montezuma to the shores of Tripoli" in the
Marine Corps Hymn refers
to the Marines' involvement in the Mexican-American War (following annexation of
Texas) and the First
Barbary War (Muslim pirates commandeering cargo ships), respectively. "Leathernecks"
refers to heavy leather straps worn on Marines' necks to protect against sword strikes.
Marines played a crucial role in various battles during the American Revolution,
such as the capture of Nassau in the Bahamas and the Battle of Trenton. During the
Civil War, the Marine Corps conducted both land and sea operations. The Marine Corps
became an integral part of the U.S. military during World War I, where they
fought in significant battles, including Belleau Wood in France. In subsequent years,
the Marines continued to be involved in conflicts and played a crucial role in the
Pacific theater during World War II, participating in famous battles like Guadalcanal,
Iwo Jima, and Okinawa. Listen to Trace Atkins' "Semper Fi."
In the diagram below is shown the foundation
chassis incorporated in a number of superheterodyne receivers manufactured by the
Crosley Radio Corp., Cincinnati, Ohio. It was common for original equipment manufacturers
(OEMs) and third-party companies to offer decorative cabinets (aka consoles) into
which the electronics (chassis, speaker, front panel controls, etc.) are installed.
In the case of this Model 120, is never had a cabinet and was meant to be integrated
into custom cabinets. No photo of the chassis could be found. Note the relative
simplicity of the circuit since there were no accommodations for fancy push-button
tuning and tonal adjustments. Standard consoles are the models Super-Administrator
and Super-Rondeau; while the Super-Sondo console is a radio and phonograph combination.
The "pliodynatron"
was a special vacuum combining the pliotron and the dynatron, as detailed in "The
Saga of the Vacuum Tube - Part 14," published in the November 1944 issue of Radio
News magazine. Vacuum tube V3 performs the pliodynatron function here...
One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 280,000
per year (in eight locations on each page, with >17,000 pages). That's pretty
good exposure for $300 per month. Some companies have expressed an interest in being
able to manage their advertising accounts themselves a la the Google AdSense program...
Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
Thursday the 9th
Those of us growing up in the middle part
of the last century remember reading predictions - even promises - of fantastic
products and systems that would become reality by the end of the century (i.e.,
by midnight, December 31, 1999). Popular Mechanics, Popular Science,
Mechanix Illustrated, Science & Mechanics, all of which I
enthusiastically read, are prime examples. Examples include a flying car in every
garage, domestic robots performing tasks currently done by housewives, a cancer
cure in a pill, learning by electromagnetic programming of your brain, another pill
to control your weight, New York to Tokyo flights in two hours, cross-continental
underground bullet trains hitting 600 mph, underwater cities, lunar colonies
--- you get the picture. Some of the ideas did manage to materialize, like this
"Television on the Job" article in a 1947 issue of Popular Science. It proposes
many scenarios whereby what is now called closed-circuit television (CCTV) is used
in manufacturing processes, education, security, and experimentation in hazardous
environments. Interestingly, Dr. K. Zworykin, "the father of television," is pictured
in a meeting sketching a plan for his "television bathysphere" which dispatches
a CCTV to extreme ocean depths rather than risking humans.
"In a groundbreaking study conducted by
Zhongjie Meng and his team at Northwestern Polytechnical University, a new deployment
strategy for
tethered satellite systems (TSS) has been developed, addressing the complexity
of operating a three-body chain in space. The detailed research has been published
in the peer-reviewed journal Space: Science and Technology. The research focuses
on a tomographic synthetic aperture radar (TSAR) system, a constellation of tethered
SAR satellites. These satellites hold significant promise for rapid deployment,
which is crucial for their ability to provide stable baselines necessary for 3-dimensional
topographic mapping and tracking moving targets. Meng's team has laid down a robust
motion model for this three-body system, initially simplifying the tether as massless
and considering only planar motions. This model encapsulates the interactions between
three point masses connected by two tethers, governed by a set of dynamic equations..."
Each month, Radio-Craft magazine
ran a regular feature entitled "In Review," which covered a variety of late-breaking
news topics related to electronics and communications. Most of the time the
focus was on wireless advances, but occasionally, as in the November 1939 issue,
you would see things like a huge public address & music system installation
at Union Station or a flash about Nazi control over radio broadcasts*. Modern news
publications follow the same template with round-up type articles. The up and coming
frequency modulation (FM) scheme leads here, followed by the wonders of facsimile
machines that transmit "facsy" formatted news to remote offices, and Telefunken's
441- line "flickerless tele-film" television film projector...
The HP DV6 Inspiron notebook computer (c2010)
that Melanie uses has a buggered Backspace key that pops off all the time.
I have replaced the plastic frame underneath, but the problem is the keyboard base
metal piece that the frame attaches to has worn out catches that cannot be replaced
or reworked. The key cap had to be inverted and laid on top to work, but you can
imagine what a pain that is. After much searching, I found a free program called
KeyTweak that permits you to remap
just about any key to perform an alternate function. Norton Antivirus did not find
any problems, so I installed and ran it. Now, the F12 key performs the Backspace
function. Most people would just buy a new computer, but on RF Cafe's budget - entirely
user supported (or not, usually), we need to follow the WWII slogan of "Use it up.
Wear it out. Make it do, or do without."
"Japanese
electronics firms' real strength is their engineers, characterized by creativity,
ingenuity and an awesome willingness to work long and hard." That statement by editor
Lewis Young is the key point in this article that appeared in a 1965 issue of
Electronics magazine. That Japanese technology companies were deemed to
be only about five years behind the U.S. was a real wake-up call to America and
the European countries. Both Europe and Japan had been very diligent about rebuilding
and modernizing techniques and infrastructure since the destruction caused by World
War II. A few stories about Japan's post-war efforts report on how the government
left most of the responsibility (aka financing) up to universities and private companies.
Industry in some of the more Socialist countries of Europe had the assistance of
taxpayer subsidization and the willingness of governments to take on debt to funnel
investment money to corporations...
RF Cascade Workbook 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...
KR Electronics has been designing and manufacturing
custom filters for military and commercial radio, radar, medical, and communications
since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass,
bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for
special applications - both commercial and military. State of the art computer synthesis,
analysis and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Please visit
their website today to see how they might be of assistance. Products are designed
and manufactured in the USA.
Wednesday the 8th
Throughout John T. Frye's series of
"Carl
and Jerry" stories, there are times when one or the other needs to convince
his technosleuth buddy that a particular project is worthy of undertaking. In the
early days while the boys were still in high school, Jerry was typically portrayed
as an overweight, rather lazy guy who, while well versed in electronics and mechanics,
preferred to do his thinking and acting while sitting or lying down. He always rose
to the event and did his part to solve a crime, play a joke on a friend, or solve
a problem plaguing their combined interest in amateur radio and remote controlled
model boats and airplanes. By the time they got to Parvoo University as electrical
engineering students, he had outgrown most of those tendencies. In this 1963 issue
of Popular Electronics magazine is an example of Jerry being the motivator and "expert"
on the subject of atomic magnetometers. With the ready availability of low noise,
high gain opamps and cheap audio frequency digital oscilloscope systems, I wonder
why the described type of atomic metal detector is not widely used today...
Empower RF Systems' model 2240 is a compact,
lightweight, and rugged
pulsed amplifier that delivers a minimum 800 W peak power across the 5.2 to
5.9 GHz frequency range. The 2240 is ideal for radar systems that operate
in C band, such as air traffic control, weather forecasting, and maritime surveillance.
Capabilities include pulse widths from 1 to 500 μsec and duty cycles up to
20%. It is built with the latest GaN technology, which provides high power and high
efficiency. This air cooled SSPA is designed for 19" rack mount or bench top applications
and is 3U in height. Remote control and diagnostics are available via the Ethernet
port to a LAN with either a Web browser or M2M (Machine-to-Machine) interface or
using the Local Touchscreen panel. The control system runs an embedded OS (Linux).
Empower RF's ISO9001Quality Assurance
Electronic Design has a new online
quiz to challenge your knowledge on
data storage media / devices. It is a multiple choice exercise that provides
a score at the end. I managed to squeeze out a 50%. Every question I guessed out,
I got wrong. Admittedly, the ones I got right are from technology dating before
the turn of the century (this century, not last century - I'm not that
old). Mercury delay lines, cathode ray tubes, magnetic drums, magnetorestrive delay
lines are my history, not CXL CCISX, CXC, DXL, and PCIe devices...
JB Booher, of
TotalTemp
Technologies, sent me a link to the Winter/Spring 2009 issue of The Journal
of San Diego History, which included a feature article entitled, "Before Qualcomm:
Linkabit and the Origins of San Diego's Telecom Industry." While there are entire
books written to commemorate the lives and times of Qualcomm founders and products,
this piece does a great job of summarizing the early days of Irwin M. Jacobs and
Andrew J. Viterbi in their treks from childhood to college to the founding of Qualcomm,
including an initial venture with a company called Linkabit. TotalTemp Technologies
has been in San Diego for a long time and according to JB, used to sell thermal
test systems to
Linkabit (bought
my M/A−COM in 1979, now owned by L−3 Communications). It is not difficult to surmise
where the company name came from - "They decided to build a company that delivered
'QUAL ity COMMunications' and called their new company, Qualcomm." It is an interesting
10-minute read.
Arthur Steele is probably enjoying retirement
from Littelfuse (still in business today) by now. In 1965 he had an article published
offering guidelines on how to
select the proper type fuse for protecting the circuit at hand. The correct
choice is seldom a simple matter of adding a margin of some amount onto the known
maximum current draw, especially if you are designing for a commercial or defense
electronics project. Applied voltage, expected current surges, operational temperature
and mechanical stress (vibration & shock, etc.), applicable design regulations
(UL, Mil-Spec, etc.), serviceability, and available space are among the factors
that need consideration. Do you need a fast-blow, medium-blow, or slow-blow fuse
for that circuit? You'll have a good understanding after reading Mr. Steele's
piece. The automotive blade fuse type (thumbnail to left) so common today was not
around at the time; they first came on the scene in the 1980s...
Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your Banner Ads are displayed on average 280,000 times per year! 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. If you need your company news to be seen, RF Cafe is the
place to be...
Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
