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4 of the April 2022 homepage archives. 
Friday the 29th
 Ryan Aeronautical Company was founded in
1934, and became part of Teledyne in 1969, eventually being owned Northrop Grumman
in 1999. Ryan, which produced many airplanes and drones, was perhaps most famous
for building the Spirit of St. Louis (Ryan NYP) used by Charles Lindbergh on his
historic transatlantic flight. Ryan also dabbled in jet engines and electronics.
The "packaged
radar" concept described in this 1952 Radio & Television News magazine article
was the precursor to modular circuit assembly commonly used in military systems
to facilitate rapid field repair...
 Axiom Test Equipment, and NH Research have
reached an agreement for Axiom to become an NHR official rental partner in the U.S.
Backed by over 50 years of experience, NH Research is able to offer world class
test instruments and systems for a wide range of industries. Axiom Test Equipment,
a premier provider of electronic test and measurement equipment rentals, sales and
repair services, further expands its rental fleet of high-quality test instruments.
As NH Research's rental partner, Axiom is excited to offer NHR's high-quality products
as solutions to fill customers short-term project testing needs. This partnership
allows Axiom Test Equipment to introduce NHR's
grid simulators and battery test systems to users with shorter-term projects
and those that want to "try before buying." Users now have a choice to rent or purchase
equipment, based on their specific requirements. The list of industries now able
to benefit from the partnership include, Aerospace, Automotive, Battery, Military,
Industrial Power, and Renewable Energy...
 Location, location, and location. Those
are always half-jokingly cited as the three most important factors to consider when
deciding where to best
set up a retail business. Unfortunately, the days of scouting out a spot to
set up an electronics sales and service shop are long gone. Except for a cellphone
screen replacement service at a mall kiosk and maybe the Geek Squad desk at the
Best Buy store, there are not many places left that do consumer electronics repair
- at least as a primary vocation. This story makes a good read for anyone contemplating
setting up shop where serving the local population is a prime objective. About two
years ago, I visited a couple up-for-sale buildings being looked at by daughter,
Sally, for a business location. One building was a former TV and radio repair shop
that...
 If you are into such things, this whitepaper
entitled "Five Key Workflows
that Deliver 3D IC Packaging Success" from Siemens might be a useful bit of
info. Several factors are converging and driving the "chiplet" design revolution.
This paper explores these factors and outlines five key workflows that address and
manage the associated, new challenges. These five workflows span several interlinked
domain areas: Architecture definition, design activities, multi-physics analysis,
device-level test, and manufacturing. This paper recommends workflow adoption focus
areas that provide immediate heterogeneous integration capability benefits while
establishing...
 The term "plate
solving" (aka "astrometric solving") in astronomy has its roots in the days
when dinosaurs roamed the earth and images of the sky were captured on, gasp, glass
plates with photosensitive emulsion coatings. Attempting to identify astronomical
items on a plate, or paper photograph developed from a plate, was/is similar to
finding an unfamiliar star, nebula, or galaxy when viewing the heavens through binoculars
or a telescope. You begin with a nearby entity you are familiar with, and then move
in the direction of the object being sought. Sometimes a process known as "star
hopping" is used to move from point to point in a predictable combination of direction
and distance from the current star (or whatever). With the advent of digital photography,
software programmers have developed algorithms that assess and map all the points
in an image, then compare it to a calibrated set of points from carefully processed
images and attempt to identify all the astronomical objects in the investigated
image. Only fairly recently has a highly efficient method of computer plate solving
been available. Fortunately, the community of professional and amateur astronomers
has produced a plethora of software tools...
 Byron Goodman published a very thorough
diode modulator
article in a 1953 issue of the American Radio Relay League's QST magazine.
It was one of the first of such articles that used the very recently available semiconductor
diodes rather than the previously used vacuum tubes. Single-balanced bridge and
ring modulator circuits are presented, along with the theory behind their operation.
It would be a few years more before double balanced mixers with their abilities
to reject even intermodulation products, and triple balanced mixers with very high
overall spurious product rejection, would become commonplace...
 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...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
downconverters. Since the conception of WFT, we have introduced products that have
been purchased by a wide range of customers, from hobbyists to education facilities
to government agencies. Worldwide customers include Europe, Australia, and Asia.
Please contact Windfreak today to learn how they might help you with your current
project.
Thursday the 28th
 1954 was in middle of a time of many transitions
in the electronics world. Vacuum tubes were being replaced by semiconductors, point-to-point
wiring in chassis was giving way to printed circuit boards, FM was overtaking AM
as the preferred radio medium, and color TV was (for those who could afford it)
shoehorning itself into homes across America and the world. This article in
Radio-Electronics magazine has the Federal Communications Commission (FCC)
extolling the many virtues of telecommunications. I have not been able to ascertain
whether it is a direct reprinting of an FCC publication or an excerpted section.
At the time, there were
600,000 licensed transmitters including commercial and amateur radio operations.
Interestingly, Industrial, scientific and medical (ISM) equipment is mentioned,
although nothing about an unlicensed band have been allocated yet...
 "Electric vehicles, power tools, smart watches
-
Lithium-ion batteries are everywhere now. However, the materials to make them
are finite, and sourcing them has environmental, humanitarian, and economic implications.
Recycling is key to addressing those, but a recent study shows most Lithium-ion
batteries never get recycled. Lithium and several other metals that make up these
batteries are incredibly valuable. The cost of raw lithium is roughly seven times
what you'd pay for the same weight in lead, but unlike lithium batteries, almost
all lead-acid batteries get recycled. So there's something beyond pure economics
at play. It turns out that there are good reasons why lithium battery recycling
hasn't happened yet. But some companies expect to change that, which is a good thing
since recycling lithium batteries will be an essential part of the renewable energy
transition. How extreme is the disparity between lithium and lead batteries? In
2021, the average price of one metric ton of battery-grade lithium carbonate was
$17,000 compared to $2,425 for lead North American markets, and raw materials now
account for over half of battery cost..."
 The value of memorizing multiplication tables,
the proper spelling of words, the location of countries on a map, et cetera, is
being questioned by many people these days based on an easy access to data on the
Internet and other media. All such people need to do is get fairly close to spelling
topics of interest correctly and other people who do not subscribe to the aforementioned
philosophy have seen to it that the laziness and ignorance of those who do subscribe
are duly accommodated. I'm referring to basic life skills of course, not nuclear
science or phenology. The obvious advantage gained in memorization is
developing an intuitive feel for what the entire realm of subject entails. Strong
visual clues during the learning process augment retention of data. For instance,
electronic calculators in their various forms are great for arriving at precise
numerical answers with given input conditions. Enter an exact set of numbers and
get an exact result on the display (right or wrong, depending on the input data
and the correctness of the algorithm). Whether or not the answer makes sense and
should be believed depends on the user's familiarity with expected results...
 According to astronomical authorities, a
once-in-a-millennium (1,075 years to be more precise) year alignment of the planets
is occurring now. "During the last week of April 2022, a rare and unique planet
parade will take place when
Venus, Mars, Jupiter and Saturn will line up in the eastern sky around one hour
before sunrise. This will be a planet parade of the third kind as described above.
The last such parade of these planets occurred in 947 AD, around 1,000 years
ago," said Indian planetarium Director
Subhendu Pattnaik. The sun rises shortly before all are visible, so an unobstructed
view of the eastern horizon is needed, which I do not have. The thumbnail above
(click
it) is a
TheSkyX
simulation I just did of the sky for this morning and for the year 947 AD.
Sure enough, there they are again. History shows the last time this occurred hoards
of people bought unfired clay bowls (aka
software) from
a vendor called Ready-to-Fire Cafeteria (aka RF Cafe). Will there be a repeat this
time?
 San Francisco Circuits (SFC) has launched
its latest industry focus page, this time on PCB manufacturing & assembly for
the automotive industry. This new industry focus page on
PCBs for the Automotive Industry covers common uses for PCBs in automobiles,
automotive PCB technologies, production capabilities, & best practices. As the
circuit boards in automobiles become increasingly more complex and sophisticated,
the need for reliable manufacturing has never been more important because they're
most commonly utilized for safety measures. Automobile PCB applications include:
airbags, anti-lock brakes, LED lighting, on-board & remote diagnostics, security
systems, rear-view cameras, blinkers, & more. Adhering to Standard IPC-6012DA
ensures the quality and reliability of PCB design & fabrication...
 This entry level introduction of
differential calculus as it applies to electronic circuit analysis appeared
way back in a 1932 edition of Radio News magazine. It was written by none
other than Sir Isaac Newton himself (just kidding, of course). Author J.E. Smith
created an extensive series of lessons that began with simple component and voltage
supply descriptions and worked up through algebraic manipulations and on finally
to calculus. I remember not being the best math student in high school (OK, one
of the worst), but once I got an appreciation for the power of mathematics for analyzing
electronics, mechanics, physics, and even economics, my motivation level soared
to where I craved more of it and ended up receiving "As" in all my college math
courses. That is truly an indication that while not everyone can excel at math,
the proper environment can make a world of difference...
 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...
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas.
Wednesday the 27th
 By now, engineers and scientists have managed
to replace most vacuum tubes with solid state devices - at least for consumer products.
The one place tubes remain are in microwave oven. Those klystron tubes operate in
the 2.4 GHz band and typically output ranging from about 500 W to 2 kW.
No doubt materials and methods have changed since the 1950s, but fundamentally klystrons
of today are the same as klystrons then. Between this article and Part 1 that
appeared in the April 1952 issue of Radio & Television News magazine,
authors Joseph Racker and Lawrence Perenic provide a very nice introduction on the
topic. According to the Wikipedia entry, the name "klystron" comes from the Greek
verb κλύζω (klyzo) referring to the action of waves breaking against a shore, and
the suffix -τρον ("tron") meaning ...
 Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, is pleased to introduce their new model
IPP−8090 dual directional coupler that handles 200 watts CW and comes in a SMD
style package which is only 1.000 x 1.000 x 0.148 inches. The IPP-8090 is a unique
broadband design which provides separate coupled ports for both forward and reflected
signals with internal Terminations. Insertion loss is less than 0.30 dB, main
line VSWR is less than 1.30:1, coupled flatness is ±1.0 dB and directivity is greater
than 17 dB. Applications include commercial, military, dual use, industrial,
medical, test and measurement applications for signal monitoring...
 The circuit drawings in this
Series Circuit Quiz are a little hard to read in a few places because the original
page used light red on top of a gray background. The magic of image processing did
a pretty good job of cleaning them up to where you shouldn't have any trouble reading
them. This quiz from Robert Balin appeared in the April 1966 issue of Popular
Electronics magazine. It is one of the easier of his quizzes (although it does
have capacitors and transformers in addition to resistors), so don't tell anyone
if you score less than 100% ;-)
 Nominating these unfortunate people for
the Darwin Award (slogan "Evolution in Action)
would be a bit insensitive, so I won't. I will, however, point out that this is
a prime example of why the old saying "ignorance is bliss" is not always true. According
to the news report, a man and woman were attempting to create
fractal wood burning art (aka
Lichtenberg wood burning), in which a lethally high voltage is applied to damp
wood, producing fractal-like scorch patterns on the surface. High voltage transformers
from microwave oven klystrons and from neon signs are popular power supply sources.
Around 2 kV is the minimum for achieving impressive patterns. More than 30
people have died while engaging in the hobby. This
fractal wood burning video
demonstrates the "right" way to do it. RIP, erstwhile fractal wood burners.
 The title says "21
Years a Ham," and that was true in 1950 when this story appeared in Radio &
Television News magazine. However, 72 years later author Helen Cloutier can claim
"93 Years a Ham," if she has not yet obtained Silent Key (SK) status. As with today,
as far back as the middle of the last century organizations and publications went
out of their way to celebrate and promote "non-traditional" participants, in this
case a woman, engaged in the hobby, sport, or profession. Concurrently, those same
groups were accused of discouraging and shunning women and minorities from participation
(yes, of course some were guilty of it). Special accommodations - even laws - were
made to right the accused wrong. It simply can't be that males (particularly white
males) might be more interested in those particular activities than others. For
many decades, white males have been placed at a disadvantage regarding access to
schools, jobs, political office, and organizations, in favor of everyone else. It
is the only acceptable form of discrimination (see the update with her incredible
obituary from 2002)...
 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...
 SF Circuits' specialty is in the complex,
advanced technology of PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
Tuesday the 26th
 Here are a couple more
technology-themed comics that appeared in the May 1956 issue of Radio-Electronics
magazine. Both are indicative of the issues commonly encountered in the day. The
era was during the transition between vacuum tubes and semiconductors, but inhabitants
of either can understand and appreciate the humor. The comic from page 52 does require
you to be familiar with the copper oxide or selenium type of rectifier that spanned
both eras. Otherwise, you might wonder what the funny-looking hat on the guy's head
is (hint - it's not a hat). The 1950s was also a time of transition from electromagnetic
speaker magnets to iron magnets, so AC hum in radios could get in not just through
the audio circuits but also through the speaker itself. The page 126 comic addresses
that issue...
 "A
brief glimpse at
semiconductor history, from SCRs and TRIACs to NVIDIA's 80-billion-transistor
Hopper GPU." Says William Wong: "Electronic Design [magazine] has been
around a bit longer than I have worked in the industry - but not by much. Having
lived through it, you might think I had a good handle on how the technology progressed.
However, so much has happened over the years that's been amazing even to me. Silicon
and germanium transistors have been around since the 1950s when vacuum tubes were
king. There were metal-oxide-semiconductor field-effect transistors (MOSFETs) in
1959, starting with p-type MOS (PMOS) and n-type MOS (NMOS) logic and eventually
complementary metal-oxide-semiconductor (CMOS). Silicon has been the mainstay since
the early '60s, bumping germanium out of the way over time. There also are some
very broad areas, including digital, analog and power, when it comes to semiconductors.
Optoelectronics should be in the mix, too, but that's yet another area of discussion..."
 Before most people listened to radio and
television programming via cable, satellite, and/or the Internet, broadcasts were
received over the air, usually from local stations. A common problem in the days
of vacuum tube Ham transmitters back in the day was inadvertently causing
broadcast interference (BCI) or specifically in the case of television, TVI,
due to insufficient filtering, shielding, or design. Nowadays, we generally refer
to all such unintentional and incidental radiation as radio frequency interference
(RFI). Lots of articles were written on the subject in the 1940s through about the
1970s. Some RF spectrum is shared by more than one entity per FCC and other countries'
band plans, with primary and secondary allocations assigned for some. For example,
in the U.S., the 33 cm amateur radio band coexists with the 902-928 MHz
unlicensed Part 15 ISM (Industrial, Scientific, and Medical) band. Ditto for some
of the other ISM bands. If you're not a Ham, you might be surprised to learn that
licensed amateurs have primary rights to the band's use...
 Planar Monolithic Industries (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 shifter, a 0.01-20 GHz ultra-low-noise amplifier, a 0.1-18.0 GHz,
digital attenuator w/USB interface, a 0.01-18.0 GHz limiter, and a 0.5-18.0 GHz
SPST reflective coaxial switch. Contact PMI today for more information.
 During and immediately following World War II,
the "Monitoring Service" of the
British Broadcasting Corporation (BBC) relentlessly listened to radio broadcasts
from all over the world in order to be able to break headline news and, if appropriate,
pass strategic military information on to Allied command centers (who were simultaneously
doing their own monitoring). This 1946 Radio News magazine article tells of some
of the more significant messages intercepted and how the facility was a highly guarded
secret in order to prevent sabotage and infiltration. At the height of activity,
32 languages were being transcribed into English daily, consisting of more than
300,000 words. Voice, teletype, and Morse code were processed...
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...
 Alliance Test Equipment sells
used / refurbished
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.
Monday the 25th
 The term "drone"
is relatively new to being common parlance throughout society. Prior to the early
2000s, a drone was thought of as either the mate to a queen bee or a special remotely
controlled aircraft used by the military for target practice or for carrying out
special missions not deemed safe for human pilots. When this article appeared in
a 1952 issue of Radio & Television News magazine, drones were the exclusive
purview of the military and research institutions because of high procurement and
operational costs. With the advent of inexpensive, highly advanced spread spectrum
radio control systems by the hobby community, lightweight and powerful brushless
motors and lithium polymer (LiPo) batteries, sophisticated miniature stability and
guidance integrated circuits (processors and sensors), and advanced computer simulation,
incredibly capable and relatively inexpensive multirotor drones are widely available.
From simple toys for erstwhile non-pilots to serious R/C flyers to professional
operators, drones are everywhere. A couple days ago I saw a utility company worker
using one to inspect power lines along a country road...
 With the well-publicized electronics component
supply chain issues disrupting normal manufacturing cycles, you might want to see
this whitepaper entitled, "Electronic
Manufacturing Supply Chain Risk: Are You Vulnerable?" Many companies turn to
contract electronic manufacturers to outsource elements of their products, such
as circuit board assemblies, wire harness and cable subassemblies, full-system assemblies,
and enclosure fabrication. Products that are complex, highly engineered, and custom
configured depend on the integrity of these assemblies. Most mission-critical product
manufacturers, such as in the medical, aerospace, and defense industries, understand
the importance of protecting their supply chains from costly disruptions. Therefore,
taking active steps to reduce your supply chain risks is crucial for ensuring continuity
of your manufacturing operations...
 Having an
unusual last name like "Blattenberger" in the U.S. has caused me some abuse
over the years as many people have felt the need to either purposely mispronounce
it or make make snide comments about its length and number of syllables. Even school
teachers joined in the fray, especially on the first day of class when attendance
was being taken. My drill sergeant in USAF basic training (circa 1978), TSgt. Ramerez,
felt the need to needle me about it. People in America with surnames of German origin
were often the victims of physical abuse, alienation, and derision during both World
War I and World War II. You hear a lot about the government's internment
of Japanese Americans during WWII, but some Germans were also rounded up merely
because of their names...
 Try Googling 'cyclodos' and 'cyclophone'
and see what you come up with. I found that Cyclodos is a German company which makes
apparel from recycled inner tubes and tents (among other things), and cyclophone
is a weird bicycle-mounted contraption for blasting sound while peddling down the
street. In 1946 when this article appeared in Radio News magazine,, the
terms cyclodos and cyclophone referred to modulator and demodulator tubes, respectively,
for
pulse-time modulation applications. Fortunately, the science of pulse modulation
quickly evolved past such devices. This article goes into quite a lot of detail
on the beginnings of pulse modulation techniques developed for radar systems during
World War II. It is very informative without going into the gory details of
equations that govern the theory...
 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 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!
Sunday the 24th
 Here is your custom made
Electronics-themed crossword puzzle for April 24th, 2022. 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 or the Tunguska event in Siberia). The technically inclined cruciverbalists
amongst us will appreciate the effort...
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...
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.
Friday the 22nd
 As mentioned a while back, in the 1980s
while working at Westinghouse Oceanic Davison in Annapolis, Maryland, an engineer
who worked for knew I had recently obtained a 1941 Crosley Model 03CB console style
radio. He generously gave me his
B&K Dyna−Quik Model 650 Vacuum Tube Tester which, although formerly a very
active Amateur radio operator (since boyhood), he didn't need it anymore. The Model
650 is a very comprehensive portable tester used at one time by many professional
radio and television servicemen. My tester also had the Model 510 Accessory Socket
Panel that added an ability to test 50% more tube types. An indication that it is
one of the later model tube testers is the inclusion of a transistor testing socket.
Unlike testing vacuum tubes, all of which plugged into sockets to make them easily
replaceable, testing a transistor or solid state diode required unsoldering or clipping
the device out of the circuit and then soldering back in either the verified still
good device or a replacement. It was one of the reasons electronics servicing people
eschewed the adoption of semiconductors. That, and a lot of money was made by the
sales of replacement tubes, with a typical profit of a dollar or so per tube. The
$169.95 price in 1957 is the equivalent of about $1,720 in 2022...
 Here is an interesting whitepaper from UnitedLex
entitled "Semiconductor Patent
Portfolio Profitability Through Reverse Engineering." Having spent a few years
doing this type of work, I know it is quite interesting, and you might even find
some infringement on your own company's IP in the process. Semiconductor companies
hold untapped profitability in their intellectual property (IP) portfolio. Advancements
in reverse engineering (RE) have made it possible to scale patent enforcement, enabling
companies to create new revenue opportunities, effectively monetizing patented holdings...
 Achieving what we consider relatively simple
results with electronics indicators used to be cutting edge technology. This
6AL7-GT
Electron-Ray Indicator Tube by Ken-Rad (a division of General Electric) provided
a dual-channel electrofluorescent (i.e., cathode ray) display of relative signal
strength or tuning the new-fangled FM radio stations. It was promoted in this 1947
issue of Radio News magazine. The tube could also be used, of course, for
many other applications where signal strength from any measured process: fuel level,
voltage, temperature, stock price, phase angle, sound volume, speed, etc., needed
to be measured. Today, we have electrochemical indicators so cheap that they are
built into off-the-shelf batteries at Walmart...
 Colicraft has added another online app for
selecting their products. The new
EMI
Power Choke Impedance Finder takes your parameter inputs, then searches its
inventory of inductors and presents a list of parts that fit. You specify operational
frequency and optionally set a value range for impedance, self-resonance, current
handling, package size, DC resistance, core material, etc. After looking through
the list of qualifying coils and selecting those of interest, click on the "Analyze
and Graph" button to get a screen like the one in this thumbnail image. The components
shown here are the same ones Colicraft used in their magazine advertisement...
 In April of 1952 when this article appeared
in Radio & Television News magazine, the
bipolar junction transistor (BJT) had only made it out of the experimental laboratory
of Messrs. Bardeen, Shockley, and Brattain at Bell Labs a mere three years earlier
in December of 1948. It did not take long for commercial production to begin. Along
with being a great primer for anyone new to transistors, herein is also some background
on how the now ubiquitous BJT schematic symbol was created. Interestingly, only
Dr. William Shockley is mentioned, making me wonder whether the contributions of
Dr. John Bardeen, and Dr. Walter H. Brattain was not widely publicized early
on. Not to worry, though, because all three were duly recognized as recipients of
the 1956 Nobel Prize in Physics...
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...
 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.
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.
About RF Cafe.
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