 Friday the 1st
Thursday the 30th
 TotalTemp Technologies offers two new ways
to elevate your testing with our thermal testing products. Beyond the normal ways
that our
Thermal Platforms and Chambers help you get the job done expeditiously, TotalTemp
is offering: Thermal test equipment with Cloud Storage technology and also Outer
Space Simulation chambers. Supporting the effort to get product testing done correctly,
repeatedly with consistently reported results, Synergy Server and available cloud
storage technologies let you have your test data quickly and easily organized, with
traceability. The days of circle-chart recorders and hand plots are long gone, your
test results can be reliably automatically stored. The efficient advantages of thermal
platforms are a natural for conductive heat transfer in high vacuum applications.
With all the new hardware going into space, where service calls are rare, thermal
vacuum testing is important part of testing high altitude and satellite equipment...
 Here's a topic -
power
supply filter design - that never goes out of style. It was originally published
in a 1952 issue of QST magazine. Without bothering to worry about source
and load impedances, this brief tutorial on the fundamentals of power supply filter
design using series inductors and parallel capacitor combinations. Author Gabriel
Rumble offers a rule-of-thumb type formula for guessing at a good inductor value
based on peak-to-average expected current. This is by no means a comprehensive primer
on power supply filter design and is directed more toward someone new to the concept
of removing or reducing noise and AC ripple from the output of a DC power supply...
 RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 RF Superstore launched in 2017, marking
the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and
microwave Industry. Pasternack fundamentally changed the way RF components were
sold. Partner Jason Wright manages day-to-day operations, while working closely
with Mr. Pasternack to develop RF Superstore into a world class RF and
microwave
component supplier. RF coaxial connectors & adapters, coaxial cable &
cable assemblies, surge protectors, attenuators. Items added daily. Free shipping
on orders over $25. We're leading the way again!
Wednesday the 29th
 I really like the electronics themed comic
that appeared on page 36 of the June 1952 issue of Radio-Electronics magazine.
Like with this one, many of the ideas for the comics are provided by readers, and
then are incorporated by artists such as Frank Beaven, a frequent contributor. Note
in that comic the name of the repair shop is the first name of the guy who submitted
it - a sort of hat-tip to the guy. As with many of the comics, I have taken the
liberty of colorizing them in order to spice them up a bit. The page 78 comic represents
the frustration (and annoyance) a lot of in-home electronics servicemen had to endure
from customers who desperately want their help, but then wouldn't leave them alone
to do their jobs - and then often tried to cheat them out of the pay they earned...
 Manmade electrical noise (QRM) and natural
electrical noise (QRN) has been the nemesis of communications - both wired and wireless
- since the first signals were sent. While it is true that over the last century
the amount of "background" noise has increased significantly, the ability of modern
circuits to deal with (reject) it and/or accommodate (error correction) it has pretty
much kept up with the advancement. You might be tempted to think that "back in the
good old days" such problems did not exist, but operators were plagued by poorly
designed and inadequately filtered transmitters as well as really deficient electrical
service installation that spewed noise from transformers, inadequately grounded
transmission lines, lousy connections, and arcing motor brushes. This 1930 article
from Radio-Craft magazine was written by a serviceman who troubleshot and
solved many of the issues prevalent in his day - a very interesting read...
 "Scientists at the University of Rostock,
in close collaboration with partners from the Vienna University of Technology, have
developed a novel process that can
render artificial materials transparent or even entirely invisible, on demand.
Their discovery was recently published in the renowned journal Science Advances.
Turning something invisible is a common trope in science fiction, such as the Cloak
of Invisibility in Harry Potter. Certainly, it sounds cool, but the reason it is
so common in stories is that it would be incredibly useful technology. The uses
for espionage and the military are obvious, but there are far more applications.
Given its immense usefulness, it may not come as a surprise that this is something
scientists and engineers have been actively working on. They've had quite a bit
of progress too, using molybdenum trioxide, metamaterials, metascreens, and dielectric
materials to fashion invisibility cloaks. It all comes down to manipulating light
in the proper way, and what is especially marvelous is that innovation in this
 Empower RF Systems is a global leader in
power amplifier solutions. Empower RF Systems is an established and technologically
superior supplier of high power solid state RF & microwave amplifiers. Our offerings
include modules, intelligent rack-mount amplifiers, and multi-function RF Power
Amplifier solutions to 6 GHz in broadband and band specific designs. Output
power combinations range from tens of watts to multi-kilowatts. Unprecedented size,
weight and power reduction of our amplifiers is superior to anything in the market
at similar frequencies and power levels.
 Center of Telecommunication Technologies
(CTT) is proud to announce immediate availability of version 2.0 of their popular
Antenna Pattern Editor.
Antenna Pattern Editor 2.0 is a universal tool to view, create, edit and convert
antenna patterns. See the New Features in Antenna Pattern Editor 2.0 list at the
left. The main idea embedded in the program is to provide the user with the opportunity
to quickly create an antenna pattern file using various methods. Antenna pattern
file is a simple text or xml file that describes the main characteristics of the
antennas - radiation patterns, gain, frequency range, name, manufacturer and other
data. These files are used in various radio planning tools including our RadioPlanner,
Indoor Radio Planner, and MLinkPlanner. There are a large number of antenna pattern
file formats, but it often happens that there is no file in the required format.
In this case, using the Antenna Pattern Editor, you can easily convert the file
to the format you need. Sometimes the antenna information is just a picture of the
antenna pattern. In such cases, using the Antenna Pattern Editor, you can prepare
the necessary file in just a few minutes...
 This
reactance measuring bridge circuit which appeared in a 1931 issue of Radio−Craft
magazine employs a very unique element for generating an alternating current: an
electromechanical buzzer which doubles as an audio source. Sure, it doesn't produce
a pure sinewave, but for the method used here to determine inductance and capacitance
it does not matter. Rather than attempting to measure an absolute value of inductance
or capacitance, a known reactance is used as part of a balanced bridge. This is
by no means a precision instrument since accuracy depends on the user's interpretation
of the presence or absence of an audible "buzz" in a pair of headphones, but in
an era when "real" test equipment was beyond the budgets of many (maybe most) hobbyists,
the scheme was better than nothing at all...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
Tuesday the 28th
 In no way do I advocate going back to the
"old ways" for manufacturing electronic components, but I do admire and like to
give credit to the people who used to perform the tedious procedure of
building vacuum tubes, hand-wire chassis assemblies, circuit boards, etc. This
1932 issue of Radio−Craft magazine article is good example. The process
required being able to sit or stand at the same work station and perform the same
range of operations day after day, often for years on end. Of course at the time,
automation processes were not what they are today and machinery needed to be driven
by mechanical means using motors, solenoids, and limit switches. That made employing
people more financially rewarding than using a machine. You can find details on
the algorithms and methodology for designing those contraptions in older engineering
handbooks. It is an amazing sight to to tour a WWII vintage battleship and look
at the hardware that stabilized and steered the cannons without an electronic computer
in sight...
 "Researchers have discovered a
single-molecule switch that can act like a transistor and store binary information
such as the 1s and 0s used in classical computing. The molecule is around five square
nanometers in size - more than one billion of them would fit onto the cross-section
of a human hair. The researchers believe that molecules like the ones they have
discovered could offer information density of around 250 terabits per square inch,
which is around 100 times the storage density of current hard drives. The smart
molecular switches as seen with a scanning tunneling microscope. In the study, molecules
of an organic salt can be switched using a small electrical input to appear either
bright or dark, providing binary information. This information can be written, read,
and erased at room temperature and in normal air pressures. These are important
characteristics for practical application of the molecules in computing storage
devices..."
 There was a time when having a career in
any field of
electricity or electronics related work was an enviable mark of a person's technical
prowess that conveyed a degree of respect. The whole controlling of electrons thing
boggled the minds of most people, whether it meant wiring homes and buildings for
lights, receptacles, and motors, or designing "all wave" radio sets for listening
to the evening broadcast of "The Lone Ranger." Today, with nearly everyone alive
having grown up with such conveniences, the "wow factor" is pretty much gone, except
maybe with those of us who still chose to engage. If an electronics appliance or
device stops working nowadays, it is discarded rather than repaired. This 2-page
advertisement from a 1946 edition of Radio News magazine inviting men to
become a "bonded electronic technician" is typical of those found in the era, and
even in the 1920s and 1930s...
 The Radio Service Data Sheets that were
published in Radio−Craft magazine usually seem to have more information
included than those published in other magazines, at least in the same era (1940-ish).
It might have to do with how much material is provided by the manufacturer rather
than a decision by the magazine editors. Either way, here are the schematics, chassis
layout, and service info for the
Lafayette Model B−100 through B−103. As with most radios built in the era, the
woodwork and artistic design of the cabinet are exquisite. There are still people
searching for such data, but fortunately the Internet is making it much easier to
locate. None of the three models show up on eBay as of this writing...
 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.
 Aegis Power Systems is a leading supplier
of AC-DC and
DC-DC power supplies for custom and special applications. Aegis has been designing
and building highly reliable custom power supplies since 1995. They offer a complete
line of switch mode power supplies and power converters for a variety of markets
including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft,
EV, telecom, and embedded computing applications. Design and manufacture of custom
power supply solutions to meet each customer's exacting specifications. Please visit
Aegis Power Systems today.
Monday the 27th
 This advertisement for a
Zig−Zag Antenna, offered by Trio Manufacturing, appeared in a 1952 issue of
Radio−Electronics magazine, states "patent pending." When I looked up "zig−zag
antenna" at the U.S. Patent and Trademark Office (USPTO), the earliest assignment
I could find for that configuration was US3213457A, "Zig−zag antenna," designed
by John W. Carr and assigned to Lockheed Corporation, in 1961. Maybe Trio never
received a patent, or my search wasn't thorough enough. The claim to fame from Trio's
design is that the zig−zag pattern consisted of various element lengths that resonated
on specific channels while all others acted as parasitic elements. I don't know
if it is coincidence or intention (probably the latter), but there are twelve sections
that might correspond to channels 2 through 13. There are not many (if any) zig−zag
antennas being sold by companies today for amateur or other uses. It evidently was
just another fad to have something different from all the rest - and there were
lots of unique TV antenna configurations back in the day which promised to pull
in far-away stations, reduce ghosts, noise, etc...
 "The Hybrid Channel Emulator is one of the
projects that is currently being developed as a part of ESA's ongoing ARTES (Advanced
Research in Telecommunication Systems) program. The HCE is developed under a
strategic goal namely 'Space for 5G' and the aim of the project is to design an
emulator which can emulate radio propagation conditions of two bi-directional 5G
carriers with accurate emulation of satellite-satellite and satellite-terrestrial
link characteristics. The objective of the Hybrid Channel Emulator project is the
development and validation of a single solution capable of emulating the radio propagation
conditions of two bi-directional 5G carriers (satellite-satellite or satellite-terrestrial).
This has the twin challenges of providing an emulator that accurately models the
dynamics, and tightly controls the channel impairments, of a wide variety of scenarios,
and one that covers frequency bands spanning nearly 30 GHz..."
 Quantic PMI, a leading supplier of custom,
high-reliability
MIC/MMIC components and subsystems for applications in space, military, communications,
commercial and consumer electronics systems for more than three decades, recently
introduced five new products in their extensive line of RF and microwave components.
Included are an 8-12 GHz digitally tuned phase attenuator, a 333 to 368 MHz
variable frequency comb generator, a 0.5 to 18 GHz 4−way power divider, an
8 to 12 GHz digitally tuned phase shifter, and a 0.1 to 40 GHz SP2T absorptive
switch. Contact Quantic PMI today for more information...
 This item from Tarek Mealy showed up on
my LinkedIn feed. He created a nifty software app called "SymMos" that allows
you to use a drag-and-drop interface to create a schematic using MOSFETs, resistors,
inductors, capacitors, bias voltages, and signal sources. Then, click on the appropriate
button to get the transfer function equation for input impedance, gain, transconductance,
or noise figure. SymMos is a work in progress and is available as a free download.
After unzipping the file, you need to change the SymMos.txt file extension to .exe.
Launch the executable and then you'll need to wait many seconds while the program
loads (a black screen is displayed while waiting). BTW, Norton flagged the file
as dangerous since it is new and hasn't seen it before, but I allowed it to run
anyway with no problems. I recreated the example shown in the YouTube video and
it works as advertised...
 "If you have dark eyes and blonde hair and
are under 30, you're due for some easy squeezing. Milligan's Appliance Center, 84
Main Street, is giving every girl between 16 and 30 who has these striking features
a newly patented orange squeezer, to introduce the new item ... Note: Any traces
of recent peroxide rinse will disqualify applicants." That is advertising copy offered
as an example of effective promotional material in a 1947 edition of Radio News
magazine. My first reaction was to think how something like that would never fly
today, but then I wasn't so sure. It seems there must be anti-discrimination laws
in this "offend nobody" climate today that prohibits singling out a certain demographic
for inclusion or exclusion; however, there are many such promotions run today such
as members only, active military and student discounts, senior citizens, etc. It
is clear that these days
only certain privileged sectors of society are still allowed to discriminate...
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...
 Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
Sunday the 26th
 With few exceptions, I, RF Cafe webmaster
Kirt Blattenberger, have for more than two decades designed a custom crossword puzzle
every week for the benefit of website visitors. This
Science
Theme Crossword Puzzle for was created for June 26th, 2022. All crossword puzzles
use a personally built dictionary of thousands of words and clues related to RF,
microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and
other technical subjects. As always, this crossword puzzle 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 or the Tunguska event in Siberia). The technically inclined cruciverbalists
amongst us will appreciate the effort. Enjoy!
 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.
Friday the 24th
 Supreme Publications was another of the
more prominent publishers of electronic equipment service manuals back in the middle
of the last century. Howard W. Sams Photofact was of course the most well-known,
but there were others including this one and Rider Service Manuals. Supreme Publications
claims their content is provided by the manufacturers; to wit, " factory instructions
for troubleshooting, repairing, and alignment." For a mere $2.00, a service shop
could have the required data to service every AM and FM radio and television receiver
produced for model year 1948, when this issue of Radio News magazine was published.
According to the BLS Inflation Calculator, that's the equivalent of $24.56 in 2022
- a pretty good deal. A version of the manual with extra diagrams could be had for
an additional 50¢...
 As the opening sentence indicates, National
Company ran a very long series of advertisements in QST magazine that were
in a format more reminiscent of a short essay than a company promotion. This installment
for the December 1952 edition was number 224. Subjects ran the gamut from technical
innovations from the company's research and development laboratory to social and
political issues relevant to electronics technicians, hobbyists, students, and engineers.
Being that it was a presidential election year in the U.S.,
National Company felt compelled to remind readers of their patriotic duty to
vote. Although this was the December issue, it would reach readers' mailboxes prior
to the election. Dwight D. Eisenhower ran against Adlai Stevenson. The latter won
the South and the former won everything else. Note the thinly veiled criticism at
the bottom about why amateur radio participation rate was down at the time...
 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.
 RF Cafe visitor
Jonathan Zane (KC2SHO) recently sent me a hyperlink to his collection of photos
taken when he visited a
broadcast facility in Balkhash, Kazakhstan. A sample of his extensive image
cache is shown here. You can view the entire set that includes vintage electronic
equipment, facilities, and city streets on his
kc2sho.com website. You
will see a huge stash of vacuum tube assemblies, large coaxial cables, operation
and maintenance manuals, and spare parts. These kinds of treasure troves exist all
over the world; it's a matter of finding them. Imagine what all that abandoned equipment
and components would sell for on eBay! Along with requesting permission to post
a few of his photos, I invited him to provide some text to accompany them. Here
is what he wrote - you will definitely like the anecdote at the end. Many thanks
to Jonathan for this!
 "Researchers have demonstrated a silicon-based
optical communication link that combines two multiplexing technologies to create
40 optical data channels that can simultaneously move data. The new chip-scale optical
interconnect can transmit about
400 GB of data per second - the equivalent of about 100,000 streaming movies.
This could improve data-intensive internet applications from video streaming services
to high-capacity transactions for the stock market. 'As demands to move more information
across the internet continue to grow, we need new technologies to push data rates
further,' said Peter Delfyett, who led the University of Central Florida College
of Optics and Photonics (CREOL) research team. 'Because optical interconnects can
move more data than their electronic counterparts, our work could enable better
and faster data processing in the data centers that form the backbone of the internet..."
 Simpson Electric is a name most RF Cafe
visitors are probably familiar with as being the maker of high quality analog multimeters,
with the Simpson 260 line being the most famous (it is still manufactured today).
Not as many people, however, know that Simpson also used to make oscilloscopes.
This article from a 1957 issue of Radio & TV News magazine was written
by a Simpson Electric engineer whose job was, in part, to respond to questions asked
by users. It covers basic operations like how to calibrate the display, adjust the
horizontal time base and vertical amplitude scales, and how to synchronize the display
with the input signal. Some explanation of
how to interpret periodic and pulse type waveforms is provided as well as tips
on how to avoid overloading and possibly damaging the instrument...
RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 ASC designs and manufactures hybrid, surface
mount flange, open carrier and connectorized amplifiers for low, medium and high
power applications using gallium nitride (GaN), gallium arsenide (GaAs) and silicon
(Si) transistor technologies. ASC's thick film designs operate in the frequency
range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up
to 20 GHz.
Thursday the 23rd
 The March 1954 issue of Radio−Electronics
magazine provided five
electronics-themed comics for readers to enjoy. Thanks to a certain individual
who has posted hundreds of these vintage comics, you are able to also able to benefit
from them. The themes are a bit dated and might not be familiar to those of you
not familiar with the issues of concern to people of the era. Television was a fairly
new technology for most households, and there was a mixture of joy and frustration
by owners because while they were thrilled with being able to watch TV, signal reception
and equipment reliability could be a real headache. Just as with today's rapid advance
in electronics technology, the pace of new and wonderful products being introduced
to the market was impressive, although many ideas were too far ahead of reality
to facilitate a successful market introduction - like for instance the video-phone
featured in the comic on page 106. Stereo sound was another high-end feature addressed
in the page 104 comic. I won't even comment on the nudist colony comic...
 "The semiconductor market in 2022 is weakening,
says Semiconductor
Intelligence, driven by inflation, the Russian war on Ukraine, COVID-19 related
shutdowns in China, and lingering supply chain issues. Four of the top 14 semiconductor
companies (Intel, Qualcomm, Nvidia and Texas Instruments) are expecting lower revenues
in 2Q 2022 versus 1Q 2022. All four cited COVID-19 related lockdowns in China as
a factor. China locked down several major cities including Shanghai and Beijing
in April in May due to rising COVID cases. The shutdowns were lifted on June 1,
but since then temporary shutdowns were re-imposed to fight emerging cases. The
shutdowns significantly impacted manufacturing in China. Six non-memory companies
expect revenue growth in 2Q 2022 from 1Q 2022 ranging from 3% to 7%. Three of these
companies (Infineon Technologies, STMicroelectronics and NXP Semiconductors) have
significant automotive business contributing to their growth..."
 Copper Mountain Technologies (IMS 2022 Booth
#10036) is excited to announce the unveiling of its
Multiport USB VNAs during IMS2022 in Denver, Colorado. SN5090 vector network
analyzers are a competitively priced, versatile multiport solution with excellent
dynamic range and measurement speed available in 6-, 8-, 10-, 12-, 14-, and 16-port
configurations. The SN5090 VNAs are an organic extension of the Compact VNA family.
This enables the full complexity of VNA measurements, a streamlined calibration
process, and reduced test times. The SN5090 hardware can fit a 19" rack and utilizes
robust, durable port connectors with ergonomic positioning for simplified cable
connection. SN5090 features CMT's next-generation software that delivers an intuitive
and contemporary user interface compatible with both Linux and Windows OS. The SN5090
VNAs enable dependable and accurate testing of various DUTs: multiport antennas,
integrated circuits, switches, interconnects, cable assemblies, diplexers, etc.
Relevant applications include telecommunications, automotive, satellite, aerospace,
defense, and many other industries that require multiple input/output components...
 When you think of printed circuits, probably
what comes to mind is what is really a photo-etched circuit board. In the early
days of
printed circuits a lot of the circuits actually were "printed" on a substrate
of some sort. A silkscreen process was often used for low resistance interconnects
and printed inductors, as well as for printed resistors on materials like fiber,
plastic, phenolic, and even (yikes) asbestos board. There is still what is called
a thick film screen printing process used today primarily in military systems, but
overwhelmingly the photo etching process is used to generate circuit boards. In
the era of vacuum tubes, it was not uncommon to have grid biasing circuits printed
directly on the glass enclosure using a resistive paint and then trimming for the
target resistance by removing excess material. This 1950 Radio & Television
News magazine article shows an example of a circuit printed on a 6J6 twin-triode
tube...
 San Francisco Circuits (SFC) has released
a report on the global integrated circuits/chip shortage that has impacted numerous
industries around the world. This new
PCB Component Shortage Report explains the key factors that have led to the
shortage, how it is currently affecting many industries, and provides multiple mitigation
strategies to help designers make it through this challenging semiconductor market.
While the global pandemic certainly contributed to the current component shortage,
supply disruptions were already happening well before factories began shutting down.
Stockpiling specialized components, designing against obsolescence, and recycling
chips are a few strategies that will help designers make it through these difficult
times. Partnering with a PCB fabrication and PCB assembly provider is another key
strategy that will help when sourcing components in short supply. SF Circuits
has a strong reputation and many connections with various suppliers...
 Here is a brief primer on
mutual inductance between inductors (aka coils), compliments of the July 1934
issue of Radio News and the Shortwave magazine. It is lesson #31 in a series.
Mutual inductance is your circuit's friend if you want it to occur, as with a transformer,
or it can be your circuit's mortal enemy if you don't want it to occur, as when
two inductors "talk" to each other unintentionally because of proximity and relative
orientation. One form of mutual inductance not mentioned here but of utmost importance
(and necessity) to radio is that existing between elements in a directional antenna
like a Yagi or log periodic configuration...
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
 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.
Wednesday the 22nd
 Following on the heels of the record-setting
demand for the January 1975 issue of Popular Electronics magazine (Part 1),
this February edition contains the second part of the
Altair 8800 Minicomputer article. The first article covered theory of operation
and constructions of the Altair 8800 Minicomputer, then the one introduces
the concept of computer programming. BASIC (Beginners' All-purpose Symbolic Instruction
Code) came about in the 1960's, but it was not until Altair BASIC (created by Microsoft)
hit the community in 1975 that it really started being used by a larger cadre of
programmers. It was for the Intel 8080 microprocessor, which the Altair 8800
used. Interestingly, BASIC is not referred to in this article; rather, machine language
code is demonstrated. The authors probably did so in order to emphasize the relationship
between the instructions being given and the actual machinations of the microprocessor
and logic circuitry...
 everything RF is once again covering
on-the-spot coverage of the IEEE MTT-S International Microwave Symposium (IMS 2022), this
year being held in Denver, Colorado. Please stop by an greet them in
Booth #6016. This event is planned to be a live show with various technical
programs. New in 2022 will be the Systems Forum, which is a three-day forum that
will bring together the latest in telecommunications, radar and space applications.
The organizers have announced an Industrial Showcase, an Industry Paper Contest
and an Interactive Forum. The Industrial Showcase will have industrial authors showcase
their work and answer questions regarding their work or organization. There will
be contributions from MTT-S Sister Societies, RFIC and ARFTG. The IMS2022 will also
continue the program where the 50 top-ranked papers, as determined by the Technical
Paper Review Committee, will be invited to submit the paper to the IEEE Microwave
and Wireless Components Letters (MWCL) for publication.
 It wasn't all that long ago that deadlines
for magazine printing cycles were measured in months - unlike today where electronics
on-demand printing has cut lead times to weeks and even days. Accordingly, this
National Schools advertisement pitching "after the war" training in electronics
servicing that appeared in the September 1945 edition of Radio−Craft magazine
was likely designed and submitted two or three months ahead of the publication month
(e.g., in June or July). How could they be so sure that their scarce advertising
dollars wouldn't be wasted? Simple. By that time, the entire country seemed to have
a sense that World War II would come to an end soon since Hitler's, Mussolini's,
Tojo's, and other Axis Powers' forces were under severe stress and suffering profound
defeats in every theater. Surrender was deemed imminent. It was as if word had leaked
earlier in the year that Little Boy and Fat Man were under construction and about
to deliver the debilitating and psychologically devastating blow that would finally
end the saga. It turns out they were correct...
 Innovative Power Products (IPP), a designer
and manufacturer of RF and microwave passive components for more than three decades,
is pleased to introduce its
2022 Catalog. IPP has been designing and manufacturing RF and Microwave passive
components since 2005. We use the latest design tools available to build our baluns,
90 degree couplers, directional couplers, combiners/dividers, single-ended
transformers, resistors, terminations, and custom products. For us, "Engineering
Driven, Customer Focused" is not just a tag line but the way we do business. This
catalog contains a list of our most popular products. Please visit our website for
a more comprehensive and current product listing containing detailed mechanical
drawings with electrical specifications, performance data, S-parameters, and .STP
files. Come visit us at booth #4110 at the IMS show June
21 – 23 in Denver!
 Membership in the
American Radio Relay
League (ARRL) is currently $49.00 per year, and includes a subscription to its
flagship publication, QST. According to this postcard insert that I found in a June
1940 issue of QST, membership then was a whopping $2.50, and it also included the
magazine subscription. According to the Bureau of Labor Statistics' online Inflation
Calculator, $2.50 in 1940 bought you what you buy for $51.83 in 2022 (it was $42.59
in 2016 when this was first posted). Because of the extremely high rate of inflation
today (2022), the effective cost of ARRL membership is less today than in 1940.
To wit, $49.00 in 2022 would have been $2.36 in 1940. BTW, postage for mailing a
postcard in 1940 was a mere 2¢, and today is 40¢. In inflationary terms, 2¢ in 1940
bought...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 Withwave manufactures an extensive line of
metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated
4-port vector network analyzer (VNA) calibrator, between- and in-series connector
adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes &
probe positioner. Special test fixtures for calibration and multicoax cable assemblies.
Frequency ranges from DC through 110 GHz. Please contact Withwave today to
see how they can help your project succeed.
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 Antenova Ltd, the UK-based manufacturer
of antennas and RF modules for M2M and the IoT, is launching GNSSNOVA M20071, a
brand new
GNSS receiver module, with power consumption reduced five-fold to enable smaller
tracker designs, and trackers that run for five times longer. The M20071 module
is for small tracking devices that operate from Li-ion batteries, where a lower
power requirement is a clear advantage. These are typically small mobile trackers,
pet trackers, personal fitness devices, and location trackers for bikes and e-scooters.
The M20071 tracks the GPS, Galileo, GLONASS and BeiDou constellations simultaneously,
this improves position accuracy particularly in urban environments. Based on the
latest generation chip from Mediatek, it draws 17 mW of power when receiving GPS
only, and 21 mW receiving all constellations. GNSSNOVA M20071 measures 9.0 mm x
9.0 x 1.8 mm. Pairing this with one of Antenova’s compact SMD antennas makes a compact
RF solution and a way to realise slimmed down tracker...
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.
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...
 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...
It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers"
Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's"
design has been ripped off by other people and used on their products, so please
be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per
item - Cafe Press gets the rest of your purchase price. These would make excellent
gifts for husbands, wives, kids, significant others, and for handing out at company
events or as rewards for excellent service. It's a great way to help support RF
Cafe. Thanks...
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area can also significantly..."
 "The quest to transmit electric power wirelessly
and over distance has been a goal of electrical engineers since the end of the 19th
century, when Nikola Tesla tried his hand at it, to no avail. In the 1970s, NASA
and the U.S. Department of Energy engineers achieved some notable successes in
wireless power transfer
(WPT) in the kilowatt-kilometer range, their efforts spurred on by the energy crises
of the time. Interest waned, however, as energy became plentiful again. Now, with
the advent of 5G and its ability to transmit at high frequencies in the millimeter-wave-band
range, new opportunities and approaches are opening up for WPT. Researchers at the
Tokyo Institute of Technology have developed a prototype 64-element millimeter-wave-band
phased-array transceiver that can send and receive data while simultaneously receiving
power. The aim is to employ the transceiver initially as a 5G relay, and later to
integrate into Internet of Things (IoT) devices..."
 "Machine learning models
are growing exponentially larger. At the same time, they require exponentially more
energy to train, so that they can accurately process images or text or video. As
the AI community grapples with its environmental impact, some conferences now ask
paper submitters to include information on CO2 emissions. New research offers a
more accurate method for calculating those emissions. It also compares factors that
affect them, and tests two methods for reducing them. Several software packages
estimate the carbon emissions of AI workloads. Recently a team at Université Paris-Saclay
tested a group of these tools to see if they were reliable. 'And they're not reliable
in all contexts,' says Anne-Laure Ligozat, a co-author of that study who was not
involved in the new work. The new approach differs in two respects, says Jesse Dodge,
a research scientist at the Allen Institute for AI and the lead author of the new
paper, which he presented last week at the ACM Conference on Fairness, Accountability,
and Transparency (FAccT)..."
 "Mind-controlled 'metasurfaces' could be
used in health monitoring, 5G/6G communications and smart sensors, according to
Chinese researchers. Mind-controlled 'metasurfaces' could be used in health monitoring,
5G/6G communications and smart sensors, according to Chinese researchers. Chinese
researchers say they have made it possible for
humans to beam radio waves with their brains in a breakthrough that could have
uses ranging from health monitoring to mind-controlled military radar. In an air
force laboratory experiment, researchers showed that brainwaves could control and
interact with electromagnetic waves remotely. 'Our design provides users with a
universal way to manipulate electromagnetic waves using brainwaves,' said Professor
Wang Jiafu, leading project scientist with Air Force Engineering University in northwestern
Shaanxi province..."
 "The invention of the transistor by Bell
Laboratory in 1947 ushered in an era of electronic devices that were smaller and
ran cooler using far less power than their bulky and fragile vacuum tube counterparts.
Transistors function as a binary switch to facilitate electrical current from off
to on states. Radios, calculators and telephones were among the first wave of instruments
to replace vacuum tubes with the new semiconductor technology. As the technology
scaled smaller and smaller, subsequent decades saw the steady integration of silicon
transistors into devices, and today's computers, cell phones, watches, pacemakers,
and virtually every kind of electronic device relies on them for high-speed processing
and memory. Enter the
memristor, an electronic device that emulates the binary switch using a two-
and also three-dimensional matrix configuration, or cross bar array, to regulate
states of conductivity based on current resistance..."
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