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4 of the November
2022 homepage archives.
Wednesday the 30th
This set of six
electronics-themed comics appeared in the March 1956 issue of Radio-Electronics
magazine. The one on page 84 is pretty clever, but would need to be modernized in
our semiconductor era. I'm not quite getting the page 114 comic. Computer dating
is a fairly recent phenomenon - or is it? The page 142 comic suggest otherwise.
In fact, I know three married couples who met via an online dating service, all
within the last ten years; my daughter is one of them! The shopper in the page 145
comic might have misinterpreted the gist of the signs, but taken literally maybe
her assumption isn't so unreasonable. The page 148 comic shows how a "futuristic"
concept proposed in the middle of the last century has not only been realized by
2022, but has evolved much farther than imagined...
Copper Mountain Technologies (CMT) has a
whitepaper available entitled, "Near
and Far Field Measurement." It begins, "To obtain optimal performance in an
over the air RF system, the antennas must be chosen to meet specific requirements.
Performance parameters such as size, wind-loading, environmental ruggedness, transmission
pattern, bandwidth, and power handling capability should be considered. Especially
important in an RF system design is the 'link budget.' This parameter determines
the end-to-end RF loss and is affected by transmitter output power, feedline loss,
transmit antenna gain, path loss through the air, receiver antenna gain, feedline
loss once again and receiver noise-figure among other factors. A failure to meet
the link budget in an RF system design will result in noisy performance and loss
of coverage. In this application note, methods of measuring the transmission (or
reception) pattern which determines antenna gain with a VNA will be examined. Most
antennas possess some directionality to their performance..."
Radio & Television News magazine
was not normally in the practice of instructing retail outlet salesmen and service
shop owners in techniques for hacking their wares, but this article in the June
1951 issue is an exception. In it, A.W. Bernsohn, Managing Director of the
National Appliance & Radio Dealers Association, extensively outlines many
tried and true schemes for use in convincing customers that they really do need
a new, reconditioned, or rental portable radio for those lazy, hazy, crazy days
of summer*. Those were the days long before iPods, Walkmans, and smartphones, when
"portable" meant maybe smaller than a breadbox, but powered by batteries rather
than an AC outlet. If any of the featured models appeal to your sense of nostalgia
and you want to lay you hands on one again, try eBay; eventually just about everything
shows up there. M. Bensohn even covers the ramification of Regulation "W" of
the Federal Reserve Act...
"DARPA looks to build on previous success
in radio frequency power output with new
transistor-focused THREADS
program. Military and civilian uses for radar range broadly, and the possibilities
for radar applications expand almost every day. Whether they are being used to navigate,
control air traffic, track weather patterns, carry out search-and-rescue missions,
map terrain, or countless other functions, radar technologies are constantly advancing.
As radio-frequency (RF) systems, radar capabilities hinge on the ability to sense
and communicate across long distances while maintaining signal strength. Powerful
RF signal capabilities extend mission-critical communications and situational awareness,
but the microelectronic technologies that strengthen RF output - specifically, high
power density transistors - must overcome thermal limitations to operate reliably
and at significantly higher capacity. Technologies for Heat Removal in Electronics
at the Device Scale (THREADS) aims to overcome..."
When Government controls the media and
deploys military and police forces against citizens as a show of force to discourage
and suppress protesting against injustice, Government wins and Citizens die. No,
I'm not referring to the U.S. In this case China's "Zero Covid" policy resulted
in political prisoners burning to death in a quarantined apartment building. The
"White Paper Revolution" consists of people symbolically waving blank sheets of
paper. Communists cannot abide a challenge to authority, so any measure to end the
situation is justified - including murdering human beings. The world's opinion is
irrelevant, especially since global economies depend heavily on China. Politicians,
university heads, and corporate titans are all sold out to them, therefore will
comply as directed. Evidently, though, most people don't mind because Communism
is being adopted across the Earth. You've been warned...
This is a must-read article for all persons
interested in the history of wireless communications. Seriously. Stop what you are
doing and read it. I guarantee the vast majority have never heard of this challenge
to the veracity of Mr. Guglielmo Marconi's bestowed title of "father
of wireless telegraphy." Most of us are at least passingly familiar with challenges
to Samuel Morse's, Thomas Edison's, and a few other notables' claims to being the
first at a particular technical breakthrough, but herein, as penned by of Lieutenant-Commander
Edward H. Loftin, is a first-hand account of multiple successful challenges by the
U.S. Patent Office against Mr. Marconi and his company, Marconi Wireless Telegraph,
Ltd., regarding filings for patent protection. As with the other aforementioned
individuals, history writers long-ago grew tired of reminding the public of often
dubious assertions of creative individuals - other than that it seems every December
17 the media is sure to bring up Whitehead's and Chanute's claims...
RF Cafe's raison d'être is and
always has been to provide useful, quality content for engineers, technicians,
engineering managers, students, and hobbyists. Part of that mission is offering
to post applicable job openings. HR department employees and/or managers of
hiring companies are welcome to submit opportunities for posting at no charge
(of course a gratuity will be graciously accepted). 3rd party recruiters and
temp agencies are not included so as to assure a high quality of listings.
Please read through the easy procedure to benefit from RF Cafe's high quality
visitors ...
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 267,269 products from more than 1397
companies across 314 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.
Tuesday the 29th
This "Operation
of a High-Quality CCTV Camera" article from a 1965 issue of Electronics
World magazine interests me not necessarily because I am interested in CCTV's
but because it has many similarities to the video mapper system used in the radar
system I worked on in the U.S. Air Force. It was probably built around the same
era, so no surprise there. The combination of analog and digital electronics is
likely one of the earliest examples of such an integration. The digital portion
is for timing, not video processing. An electromagnetically scanned vidicon tube
is the heart of the system. Rather than using the television type composite timing/amplitude
signals that require complex circuits to deconstruct and direct portions of the
signal to appropriate circuits, this is truly digital timing. In fact, the timing
diagram show here is one of the earliest I recall seeing in these vintage magazines...
How did we ever accomplish research without
the Internet? Sure, that is a rhetorical question, but I find myself asking that
often when I find information on something I figured there was no way anything would
be available. Such was the case when looking up this
Kolster K20 radio. Its Radio Service Data Sheet appeared in the October 1930
edition of Radio-Craft magazine. Mr. Gordon Bell, WA2YQY, provided the photo
of the one to the left, which I found on the RadioAtticArchives.com website. As
with nearly all radios of the era, is has a nicely styled wooden console cabinet.
Note the simplicity of the tuning indicator...
Copper Mountain Technologies (CMT) has a
webinar coming up in league with Eravant as part of our VNA 101 Bootcamp Webinar
series titled "Software
Tips & Tricks." The CMT vector network analyzer software has a lot of features
and capabilities. During this session, we will review some aspects of the software
in more detail to help users understand how to get the most out of the software.
This is a follow-on to the previous "Fixture Requirements to Accurately De-Embed
DUTs from VNA Measurements" Webinar. Automatic Fixture Removal software may be used
to remove the effects of fixtures from the measurement of a Device Under Test. It's
fast and easy to use, but it is imperative to understand the extent to which fixture-related
measurement impairments may be compensated. During this webinar, we will review
the possible pitfalls during de-embedding and measurement of a DUT on a fixture...
While
not specifically related to RF Cafe type content, this article on the Physics.org
website entitled, "Fun Research
on Cold War-Era Ads About Flying Saucers, UFOs Finds Themes That Remain Relevant
Today," is an interesting bit of sci-fi techno-nostalgia. A study found that
although not exactly the same methods and subjects are being used to influence today's
consumers, the motus operandi (MO) are basically the same. "While ads with flying
saucers and UFOs may use them differently than in the past, desired messages and
reactions from those who place the ads have not changed. Emotion and sensation continue
to motivate purchases, and advertisers consistently seek to share messages about
quality and technology. Plus, the appetite of consumers for big events has never
waned..."
"A key objective of electronics engineering
studies focusing on radio communication is the development of increasingly smaller,
lighter, and low-power radio components. This could be achieved by integrating all
radio components into a single chip, for instance by combining acoustic microelectromechanical
systems (MEMS) with complementary metal oxide semiconductors (CMOS). Researchers
at Purdue University have recently used this approach to develop an
acoustic resonator based on commercially available field effect transistors
(FETs), which was presented in a paper published by Nature Electronics. FETs are
a class of transistor that control the flow of electrical current in a semiconductor
using an electrical field, which are commonly used to amplify signals and are the
building blocks for all logic circuits. "This paper is a culmination of years of
work involving multiple graduate students and collaborations with semiconductor
companies. 'It began with the recognition of a need for high-Q frequency sources
embedded in microchips (CMOS) despite the huge barrier to entry for any new materials
or processes into CMOS manufacturing...'"
Back in the 1970s while taking flying lessons,
I used to enjoy watching the
Civil Air Patrol run through its exercises at
Lee Airport,
in Edgewater, Maryland. For some reason, I never bothered to look into joining.
I wish I had. A few years later while in Basic Training (BT) for the USAF at Lackland
AFB, Texas, there were a couple guys in my squadron who had been long-time members
of the CAP and guess what? They only had to spend the first two weeks in BT, just
long enough to do all the paperwork processing, take a few of the classroom sessions,
get shots, examinations, a head shave, and to have uniforms issued. Then, immediately
before leaving for technical school, they got to sew a stripe onto their shirtsleeves
as an Airman 1st Class. High school ROTC guys got to do the same thing. I don't
know if the Air Force still has that policy; you might want to check it out if you're
planning on joining...
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.
The
Wireless Telecom Group,
comprised of Boonton, CommAgility, 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.
Monday the 28th
This "Glass
for Electronics" article in a 1965 issue of Electronics World magazine
provides some really interesting information about the properties of glass which
I, for one, either never knew or have forgotten. One such point is that glass is
typically defined with a "softening" temperature rather than a melting temperature.
That is because the final characteristics of the glass is highly dependent on the
cooling down time/temperature profile. Those of us having been in the world of automated
printed circuit assembly (PCA) solder oven operation are familiar with the criticality
of time/temperature profiles, so the concept is not new. In the case of PCA's, profiling
is necessary to accommodate the often widely varying thermal dimension changes over
temperature to prevent fracturing. With glass, it is the final atomic alignment
(or misalignment) that is dependent on the cooling process, akin to tempering of
metal (although the metal is not heated to the point of liquidus flow). At the time
of this article, Corning Glass Works claimed to have >100k unique formulas for
glass using various mixes of elements...
These before and after satellite photos
of
Ukraine's nighttime lighting shows the profound effect of a barrage of power
grid infrastructure attacks by Russia's military. While billions of American dollars
and state-of-the-art technology are funneled into the domonstratably corrupt government
of Ukraine, and inept, agenda- and money-driven media coverage describes how Russian
troops are being decimated, Ukraine is looking like
North
Korea at night. That's about what the whole Earth would look like if we did
a wholesale switchover to solar power;-) "It was only a matter of time. The recent
Russian pull-back of troops clearly indicated a broad shift in tactics, and the
one thing that the Kremlin avoided for several months seemed like the next most
logical step - Full spectrum strikes on Ukrainian infrastructure. Initially, Ukraine's
media spin suggested that the precision strikes were 'ineffective,' with western
news outlets showing only a handful of images of craters in streets and some scarred
apartment buildings..."
Author Howard Wright takes the opportunity
here in a 1936 issue of QST magazine to distill the concept of modulation
down to its basic operation while dispensing with the garbled mix of "graphs, formulas,
charts, vectors, diagrams, and Greek letters which often enter into various
discussions of modulation." Mr. Wright describes how to the uninitiated
radio dial spinner, the culmination of events occurring behind the scenes in an
AM reception process is akin to this: "...it might be compared to the reproduction
of a color photograph in a magazine. How would we ever know that, to be reproduced,
the picture was broken down into its primary colors, if all we had to go by was
the original print and the magazine?" That is a very apt comparison...
IEEE's Spectrum magazine has an
interesting article entitled "The State of the Transistor
in 3 Charts." Although the first transistor was built in Bell Labs in late 1947,
commercial products did not appear until the mid-1950's, and integrated circuits
until the early 1970's. Hence that's where the charts timelines begin. An accompanying
article entitled, "The Ultimate
Transistor Timeline" accounts for all major developments from the first point-contact
transistor on Christmas Eve Eve (sic) in 1947 through to today's newest transistor
innovation, the complimentary FET. Note in the chart that there are four transistor
types which have been invented but not yet commercialized (as indicated by no black
line at the end of the red bar)...
Anyone who has been in aeromodeling for
more than a decade or so is familiar with the name William (Bill) Winter. Bill has
been in the model airplane realm for longer than a lot of us have been alive and
is one of the true pioneers of the sport. He has served as editor for a couple aircraft
modeling magazines, and has written countless articles both for the magazines he
edited and for other special interest magazines. When Popular Electronics
came on the scene in the mid 1950s, Bill was editor of Model Airplane News
magazine. Radio control was beginning to mature from its infant state when only
hobbyists with an intimate knowledge of electronics were able to participate. Oliver
Read, editor of Popular Electronics, tapped Bill's ample knowledge and
skill to craft quite a few articles for his own magazine. This one, "Radio
Control Installations," appeared in the February 1955 issue. As always when
reading this type of vintage material, it is amazing how much innovation has occurred
between then and today in the fields of electronics, materials, and construction
techniques...
RF Cafe's raison d'être is and
always has been to provide useful, quality content for engineers, technicians,
engineering managers, students, and hobbyists. Part of that mission is offering
to post applicable job openings. HR department employees and/or managers of
hiring companies are welcome to submit opportunities for posting at no charge
(of course a gratuity will be graciously accepted). 3rd party recruiters and
temp agencies are not included so as to assure a high quality of listings.
Please read through the easy procedure to benefit from RF Cafe's high quality
visitors ...
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.
Sunday the 27th
November 27th's
crossword puzzle sports an electronics theme. 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!
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
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.
Friday the 25th
My first encounter with a
parametric amplifier was in the S-band search radar system I worked on in the
U.S. Air Force. That was in the late 1970's - early 1980's, and the radar was an
early 1960's era vacuum tube system with a few solid state upgrades. A silicon diode
in the receiver detector circuit, and a transistorized parametric amplifier in the
receiver front end are the only two that come to mind. I remember the etch school
instructors making a big deal out of the parametric amplifier being so great because
it could actually improve the SNR of the received signal. Even at the time, in my
youthful ignorance, it seems too good to be true, but if an ambassador of Uncle
Sam - especially one wearing five times the number of stripes on his sleeve that
had I - then surely it must be so. Leap forward a decade in time and I'm working
at General Electric Aerospace Division in Utica, New York, freshly endowed with
a BSEE degree, and while researching a design for an airborne early warning ECM
system, a thought of that miraculous parametric amplifier came to mind. There was
no Internet back then, but the place had a very nice technical library. Not much
information was available, so I asked a couple of the seasoned radar gurus about
it, but none were particularly enthusiastic, so I moved on. Over the years...
Here's a genius idea: Spend $billions and
generate tons of greenhouse gases in building, deploying, and maintaining a system
to beam sun power to Earth (which manages to arrive here
w/o any help otherwise, and w/o frying airborne birds & planes in the process).
"Solar power could be gathered far away in space and transmitted wirelessly down
to Earth to wherever it is needed. The European Space Agency (ESA) plans to investigate
key technologies needed to make
Space-Based Solar Power a working reality through its SOLARIS initiative. Recently
in Germany, one of these technologies, wireless power transmission, was demonstrated
to an audience of decision-makers from business and government. The demonstration
took place at Airbus' X-Works Innovation Factory in Munich. Microwave beaming was
used to transmit green energy between two points representing 'Space' and 'Earth'
over a distance of 36 meters..."
I
never engage in the "woke" practice of promoting certain people because of real
or imagined oppression. Nor do I denigrate real or imagined "privileged" people.
My decision to acknowledge accomplishments is based on merit and character, regardless
of history. If significant enlightening information comes to my attention regarding
any aspect of technology and I deem it of value to RF Cafe visitors, it receives
front page space. Such was the case with the Hidden
Figures movie, and is the case with this "The Women Behind ENIAC"
article from IEEE's Spectrum magazine. "If you looked at the pictures of
those working on the first programmable, general-purpose all-electronic computer,
you would assume that J. Presper Eckert and John W. Mauchly were the only ones who
had a hand in its development. Invented in 1945, the
Electronic Numerical
Integrator and Computer (ENIAC) was built to improve the accuracy of U.S. artillery
during World War II. The two men and their team built the hardware. But hidden behind
the scenes were six women - Jean Bartik, Kathleen Antonelli, Marlyn Meltzer, Betty
Holberton, Frances Spence, and Ruth Teitelbaum - who programmed the computer to
calculate artillery trajectories in seconds. The U.S. Army recruited the women in
1942 to work as so-called human computers - mathematicians who did calculations
using a mechanical desktop calculator. For decades, the six women were largely unknown..."
"It is anticipated that within a few years
if we do not have new methods and new machinery, there will be a
shortage of manpower to produce the goods and services needed to sustain the
American standard of living." Those words, noted in this 1960 issue of Electronics
World magazine, were uttered in the same year by U.S. Senator Hiram Fong, of
Hawaii (first name ring a bell?). His was an admonition against ignoring the need
for highly trained workers for the country's burgeoning technical fields. "A few
years ago, there were no electronics industries, no atomic energy projects, no missiles
or rockets or space vehicles. New vocations, created in the past ten or fifteen
years, run the full spectrum of man's pursuits and offer careers undreamed of only
a few decades ago." "Fifteen years from now, supersonic airplanes will bring Paris
within two hours of New York and Geneva about three hours from Los Angeles. Space
travel will approach reality. In 1961 we hope to launch our first man into space
with safe return; about 1970, to transport an American astronaut to the moon [accomplished
by July 1969]." Senator Fong was prescient in his remarks. His remarks about work
ethic would be lambasted today by pols promising work-obviating government handouts
and free healthcare in exchange for votes...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets
exceedingly high standards of quality, performance and excellent value, and are
100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz.
Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production.
All products are custom designed. We will find a solution and save your time and
cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Thursday the 24th
A few years ago, I posted an article about
the restoration and installation of my
Alliance Model U-100 Tenna-Rotor. I'm not sure of the exact vintage of my Model
U-100 Tenna-Rotor, but this full-page advertisement from a 1956 issue of Radio-Electronics
magazine presents the Alliance Tenna-Rotor Model U-98, so mine must be sometime
after that. From what I can tell based on the ad, the controller appears to be the
same or very similar. "Model U-98 - fully automatic - incorporates 32 distinct improvements
- eliminates all arcing and consequent picture distortion - points directly, positively,
instantly to target station - 'just set it and forget it!'" It seems they forgot
to make a couple other needed improvements. As I mentioned in my article, the ker-chunk,
ker-chunk of the solenoid stepping through the angle increments is a very strongly
nostalgic memory from the days of yore, back at 114 River Road, in Mayo, Maryland...
Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his November 2022 newsletter that
features his short op-ed entitled "Face Reality: Level 5 Vehicle Autonomy Won't
Be Here Anytime Soon." A definition of Level 5 on the level5auto.com website
declares thus: "Level 5 driving is full driving automation. That is, the car's systems
can accomplish every part of the dynamic driving task (DDT). They can also monitor
all of the vehicle's surroundings and make predictions about what the objects in
the space around it will do next. Further, the car can do this anywhere. The systems
are no longer confined to a limited operational design domain (ODD). And, finally,
the car operates without the expectation or need for a human to ever take over driving
- even in the case of a system failure." The scheme requires not only perfect AI
(artificial intelligence), but perfectly functioning electronics processors, sensors,
and control over the car's throttle, steering, and brakes. That's a pretty tall
order. As Sam notes, if any monitoring and/or intervention by the human occupant
is required, then Level 5 has not been achieved. Level 5 may well be an
asymptote of the vehicle autonomy curve...
"NIST, in collaboration with CU Boulder
faculty, published a paper titled: 'RF
Josephson Arbitrary Waveform Synthesizer with Integrated Superconducting Diplexers'
demonstrating results that show a significant step toward a broadband, integrated,
quantum-based microwave voltage source with useful power above -30 dBm. This
milestone creates new opportunities for improving measurements of high-accuracy
RF voltage and power for modern high-speed communications components and instruments.
NIST's goal is to advance quantum-based standards for RF communications to eliminate
costs and overhead in calibration and traceability chain measurements by providing
self-calibrated, quantum-based standards and automated measurement capability to
communication and instrument manufacturers. The voltage source is an RF Josephson
arbitrary waveform synthesizer (RF-JAWS) that utilizes a superconducting integrated
circuit that is cooled to 4K and is composed of an array of 4,500 Josephson junctions..."
My introduction to
passive intermodulation (PIM) issues was while working on a BTS switching system
back around the turn of the century (yes, this century), where because of high power
levels, the matrix had to be guaranteed to not generate PIM products greater than
a certain value. About 1/3 of the units were not passing test. The cause turned
out to be a high power attenuator in one of the paths. The manufacturer of the attenuator
was a very well established and reputable firm. The PIM levels were intermittent
and would come and go after removing and then replacing the interconnecting cables.
I fortunately noticed that the N-type connector on one end of the attenuator was
rotating slightly during the process. According to our specification to the manufacturer
(it was a custom design), the connector bodies were to be pinned to prevent movement
during torqueing. They appeared to be built properly because the small hole where
the steel pin was driven had been backfilled with conductive epoxy. When the company
was told that the connectors were rotating, they immediately blamed us (me, actually)
for abusing the connectors, since there was no way the connectors would move with
the pins in place...
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.
Wednesday the 23rd
Anyone who watched the
WKRP in Cincinnati
sitcom back in the 1970s has to remember what was one of the funniest episodes ever.
Here is the 4 minutes that made Prime Time history. In this Thanksgiving episode,
station owner / manager Arthur Carlson decided he would surprise the community with
good deed - that doubled as a promotional stunt for his radio station - by dropping
turkeys from a helicopter for lucky shoppers at the local shopping mall. Watch the
disaster unfold as Les Nessman reports live, and then see Carlson's final comment
that is still used or alluded to in many comic routines. Posting this video is an
RF Cafe tradition. Have a Happy Thanksgiving!
Hopefully, you are winding down operations
for the week and getting ready to celebrate Thanksgiving with a long weekend. This
trio of
electronics-themed comics from a 1946 issue of Radio-Craft magazine
will help get you in a jovial spirit, regardless of whether or not you're getting
the long weekend. I've mentioned many times that these comics make a good source
of levity for adding to your presentations. As you might have guessed if you are
familiar with Frank Beaven, he drew the top and bottom comics. He also drew the
middle one. Two of these comics are part of his "Radio Term Illustrated" series,
where magazine readers sent him suggestions for a theme that could serve, along
with his drawing, as a sort of double entendre. Enjoy!
Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, is pleased to introduce the
IPP-5004, a unique 3-port Balun that, as a divider, splits an unbalanced input
signal at the sum port J1 into a balanced signal output pair at J2 and J3. The balanced
signals are equal in amplitude and have a 180° phase shift between them. As a combiner,
the Balun will sum the balanced signal pair into one unbalanced output at the J1
sum port. The IPP-5004's unbalanced impedance at the sum port J1 is 50 ohms and
the unbalanced impedances at J2 and J3 are 25 ohms referenced to ground. The operating
frequency is 30-1500 MHz with a power rating of 100 W. The insertion loss is
less than 0.60 dB, main line VSWR is less than 1.35:1, phase balance is ±7° and
amplitude balance is ±0.60 dB. This Balun is produced in a small surface mount
(SMD) package with a 1.10" x 1.15" footprint and is available on tape and reel to
pick and place for high volume applications...
Wow, a $50,000 helicopter! You can't touch
a new heli these days for less than a third of a million dollars (like a Robinson
R22). 1959 marked the early days of helicopter traffic reports, I'm guessing before
the really good noise cancellation headsets were available, so drivers down in the
traffic snarl tuned in their AM radios and got a lot of reporters yelling into the
microphone to overcome the rotor chop-chop-chop sound in the background. According
to this 1959 Popular Electronics magazine article, an airborne GE unit of the era
transmitted 3 watts at 26.19 mc (MHz), and received on a triple conversion, crystal-controlled
receiver. If you look at the one photo, you'll see a Handie-Talkie on the passenger
seat...
Alliance Test Equipment sells
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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.
"Researchers from NC State University have
demonstrated a new technique for directly
printing electronic circuits onto curved and corrugated surfaces. The work paves
the way for a variety of new soft electronic technologies, and researchers have
used the technique to create prototype 'smart' contact lenses, pressure-sensitive
latex gloves, and transparent electrodes. 'One challenge is that existing techniques
require the use of polymer binding agents in the 'ink' you use to print the circuits.
This impairs the circuit's conductivity, so you have to incorporate an additional
step to remove those binding agents after printing.' 'A second challenge is that
these printing techniques typically require you to print on flat surfaces, but many
applications require surfaces that aren't flat..."
For many years I have been scanning and posting
schematics & parts lists like this one featuring the
General Electric Model 280 tabletop radio. It appeared in a 1947 issue of
Radio News magazine. Unlike with most of these documentation sets, no functional
description or tuning data was included. I did find a few pages from the John F.
Rider (similar to Sams PhotoFacts) service manual - see below. The thumbnail image
at the left is a restored GE 280 appearing on the RadioAtticArchives.com website.
There is also a shot of the inside showing the chassis, tuning dial, and speaker.
There are still many people who restore and service these vintage radios, and often
it can be difficult or impossible to find schematics and/or tuning information...
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...
TotalTemp Technologies has more than 40
years of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between -100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Tuesday the 22nd
By 1952, when this "TV
Without Radio" episode of Mac's Radio Service Shop story appeared in Radio &
Television News magazine, Mac's technician / protégé Barney had been working
there for four years. We know that because the first episode entitled "Mac Hires
a Helper" appeared in the April 1948 issue. If after all that time troubleshooting,
repairing, and aligning circuits Barney was still using a metal-shafted tool to
tweak an IF coupling transformer, either should have been a reason to fire the boy
or for Mac to consider whether he had not adequately trained him. During my USAF
radar maintenance years in the later 1970's - early 1980's, all techs carried a
variety of plastic tuning wands for making adjustments. I did have one tuning wand
that had a very small metal tip on the end of the plastic shaft because it was used
on a couple tiny (for the day) inductors in the transistorized IFF secondary radar...
The leading website for the PCB industry.
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We have listed the leading printed circuit board manufacturers around the world
and made them searchable by their capabilities - Number of laminates used, Board
thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers,
flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing,
fabrication, assembly, prototype), and more. Fast turn-around on quotations for
PCB fabrication and assembly.
"Sunshine streaming through a window could
be directly harnessed for
wireless data transmission to electronic devices. KAUST researchers have designed
a smart glass system that can modulate the sunlight passing through it, encoding
data into the light that can be detected and decoded by devices in the room. The
use of sunlight to send data would offer a greener mode of communication compared
to conventional Wi-Fi or cellular data transmission. Basem Shihada had been exploring
data encoding into an artificial light source when he had the lightbulb moment to
use sunshine. 'I was simply hoping to use a cell phone camera to record a video
of the encoded light stream to try to decode the video to retrieve the data; that's
when I thought, why not do the same with the sunlight?' Shihada recalls. 'This would
be much easier and can be done over the cell phone camera too..."
Zetta (1021), zepto (1023),
yotta (10-21), and yocto (10-23) have just been trumped
as the largest and smallest, respectively,
numerical prefixes by ronna (1027), quetta (1030), ronto
(10-27), and quecto (10-30), respectively. The last time new
prefixes were added was in 1991. "Measurement scientists and government representatives
from around the world voted in favor of adding the new prefixes at the General Conference
on Weights and Measures in Versailles, France." From whence came these strange new
prefixes, you might ask? "The need for new prefixes led ... to words that began
with the only letters not already in use as symbols for units or prefixes: 'r' and
'q.' Ending the multipliers in an 'a' for the large extreme and 'o' for the smaller
end of the scale followed the already established path. The prefixes also have the
sound of Greek or Latin numbers..." Is it a coincidence that "ronna" contains "nano"
along with the new "r?" "Quecto" contains "ecto" (i.e, outer) with "q" and the accompanying
"u."
Even if you are even old enough to remember
the
Packard Bell line of desktop computers that appeared during the PC revolution
of the late 1980s, you probably do not know that before making PCs, Packard Bell
made television sets. Before that they made radios. Herb Bell and Leon Bell formed
the company in 1933, then marketed their first radio model, the 35A. Neither Packard
nor Bell had any direct family ties to the automobile maker or the telephone company
of similar names, respectively. Packard Bell was sold to Teledyne in 1968, then
in 1986, an American businessman named Beny Alagem and a group of Israeli investors
bought the Packard Bell name from Teledyne...
A new website
named SATNow is online, serving the needs
of satellite component and equipment users. A large selection of unique, space qualified
items can be found there including sun sensors, star trackers, reaction wheels,
earth / horizon sensors, magnetorquers, ACDS systems, and satcom transceivers. Ground
station satcom transceivers and antennas, satellite link emulators, redundancy switches,
and block upconverters can also be found on SATNow. Even launch related equipment
from payload adapters and payload deployers, up through rocket engines and entire
rockets can be sourced. Save yourself valuable time by using a website - SATNow
- built specifically to locate and present the needs of satellite communications.
The first
commercial color television broadcast occurred in 1954 during the Tournament
of Roses Parade. By the late 1950s, color television sets were becoming popular
in homes, but the price, at around $500, was too prohibitive for most people to
afford. In 2014 dollars that is equal to around $4,200 (per USBLS), which would
allow you to hang a 70" Samsung UHD on the family room wall. This 1957 Radio &
Television News magazine article reported that there were only about five major
manufacturers (more, actually) making color TV sets, including RCA, Sylvania, Emerson,
Westinghouse, Magnavox, Zenith, and Philco. Most or all used a common 21" round
CRT. Over the years many television manufactures came and went, and now today there
are really only about twice as many TV manufacturers, although many brands are built
by the major companies...
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...
Innovative Power Products (IPP) has over
35 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband
couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Products listed on website
link to detailed mechanical drawings that contain electrical specifications as well
as performance data. Please take a couple minutes to visit their website and see
how IPP can help you today.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
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