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.
are a relatively new medium for presenting a large amount of information in a single
graphic using a combination of illustrations and text with numerical data. The format
is typically a high aspect vertical ratio banner, which creates a strong visual
attraction that suggests a chronological progression. Ohio University's Master of
Science in Electrical Engineering program has created this infographic with the
theme "Electrical Engineering Inventions Connect People and Communities."
Theirs is not a time progression of inventions, but more of a snapshot of
days before satellite communications (Telstar I, c1962),
long-range television broadcasts relied on an extensive
(and expensive) series of line-of-sight microwave
towers. Each site had land ownership and maintenance expenses, so there was an incentive
to streamline operations. Development of an
over-the-horizon relay system enabled a reduction in sites and
streamlining of operations - at least in theory. History shows that these installations
must not have provided the improvement needed to implement them on a larger scale
than that reported here
Daylight Saving Time
(DST) ends at 2:00 am local time this coming Sunday
morning in most of the U.S., whereupon we return to Standard Time
(ST). The event, as with the beginning of DST in March,
always elicits a lot of debate over whether DST is necessary in the 21st century.
I would prefer to end the inane biannual ritual for reasons illustrated in the graph
I created in Excel. Daylight Saving Time is not observed everywhere across the globe,
and where it is observed there are variations in when it begins and ends. In the
U.S., DST begins the second Sunday of March and ends on the first...
Selenium rectifiers were
the first widely used replacements for vacuum tubes in commercial electronic equipment.
Since amplification was not possible - that came in late 1948 with the invention
of the transistor, compliments of Shockley, Brattain and Bardeen - diode action
in AC-DC power supplies was its primary application. Typical reverse breakdown voltage
is in the neighborhood of 20 volts and current handling capability depends on the
interface surface area. Cost kept the selenium rectifiers from being widely adapted
early in their history (1933), but by 1946
a pragmatist is the polite way of saying you are a skeptic, or more seriously, a
misanthrope. At various times, I have been called all three
(along with a few other choice terms). I prefer to
think of myself as guardedly inviting of new ideas and personal acquaintances. It
might come with the territory, so to speak, when possessing a stereotypically somewhat
personality. I plead guilty and throw myself on the mercy of the court. To do otherwise
would be disingenuous. Why bring this up? Something I read this morning reminded
once a week I post these sets of schematics and parts lists for
vintage vacuum tube radio sets. Most RF Cafe visitors have no
use for them, but somewhere out there there is probably someone doing a restoration
job on one of them and will be glad to see it.
Belmont Model 5P19, Crosley Model 56FC, Garod Model 5A1,
Admiral Models 7T06, 7T12,
Arvin Models 555, 555A, 552N, 552AN, Emerson Models 507, 509, 518, 522, 535. Thanks for your indulgence.
The main selling
point for this
Snap Circuits kit is the ability to connect your music to it
and cause many different kinds of lighting effects to respond. It is a good way
to engage youngsters in electronics design because of the intense visual feedback.
Create circuits with included building blocks like transistors, capacitors, LEDs,
resistors, switches, motors and more - over 55 parts. There is also the
Elenco 130-in-1 Electronic Playground and Learning Center with
a more traditional electronics experimenter format that has many more component
types. Great Christmas gifts for kids.
This really torques me off.
Antares rocket (Orbital Sciences) was
originally scheduled to launch Monday evening at 6:45 pm to deliver supplies
to the ISS, but was scrubbed 10 minutes before t-0 due to some
dumb-a** boater running into restricted waters off the
coastline. The explosion occurred Tuesday a few seconds after lift-off. There is
a very real possibility that the explosion would not have occurred if the rocket
had launched Monday since so many new variables are added after a cancellation.
Charles Murray over at Design
News posted a video of a lithium-ion (Li-Ion) battery
going up in flames, as a reminder of the potential (pun intended)
danger posed by the chemistry used by the vast majority of our portable devices
as well as the current fleet of electric cars. In it, a guy whacks an iPad battery
pack with a hammer causing it to immediately burst into flames - an act that could
easily go way wrong and automatically self-nominate the performer for a Darwin Award.
Just as the Ford Pinto and early model Mustangs were discovered to include an unadvertised
explode-on-impact feature with ...
Buckle your mental
seatbelt before reading this fast-moving rundown of the origins of many
measurement standards used in the cgs (centimeter-gram-second)
system. It reminds me of a video you might see of a physics dude 'wowing' an audience
of science laymen as he rolls through one topic after another, among them being
mass, acceleration, time, electricity, magnetism, solenoids, pendulums, inertia,
and gravity. There's nothing you haven't seen and heard before in the first couple
chapters of Physics 101 class in the way of equations and drawings, but
If you are soon likely
to find yourself in the position of an interviewer or an interviewee, fear not.
There is plenty of advice available for consideration. What you don't say can be
as critical as what you do say. As someone who has been the successful interviewee
at least a dozen times throughout my electronics career (only
one attempt failed), my advice if you don't like rejection is as follows,
in order of importance: 1) Do not apply for a position for which you are not fully
qualified. 2) Optimize your resume and cover letter for the specific position. 3)
Know something about the company's history and
OK Go is perhaps best
known for sophisticated videos that require extremely high levels of choreography.
Their I Won't Let You Down video was posted on YouTube just yesterday
and it has nearly 2.5 million views a day later. Back in 2010 I posted their Mousetrap-like
This Too Shall Pass video; it now has more than 45 million
views. Two major aspects of high technology are featured here: Honda's UNI-CUB β
robotic unicycle and the use of a remote control
for filming the video. Honda is not selling the UNI-CUB β yet, so the company
must have been involved in the effort. The I Won't Let You Down
matter how beautiful your guess is or how smart you are or what your name is. If
it disagrees with experiment, it's wrong. That's all there is to it." -
Richard Feynman (start video @ 3:52),
populist, Nobel Prize winning physicist.
announcement of the merging of
Radio Craft and Radio & Television magazines
into a single publication was made on the eve of America's entrance into World War II.
Knowing the visionary talents of publisher Hugo Gernsback, he probably did so at
least partly due to what could be predicted as a severe contraction of the domestic
electronics appliance market once the war machine gears began cranking. It turns
out that he was in fact prescient, because history shows that the government did
direct all critical production to military equipment. Buying a new model radio
Anatech Electronics, a manufacturer of RF and
microwave filters, has published its October 2014 newsletter. As always, it includes
both company news and some tidbits about relevant industry events, regulations,
and standards. This month, Sam Benzacar offers his views on the subject of "So Many
Bands, Too Much Hardware." There are also a couple headlines on MRI on steroids,
Biggest wireless job slashers of 2014, microwave device market poised for growth,
analysts predicts 2.48% growth in EW spending, and NASA lets you
I offer up these vintage yet timeless
electronics-themed comics for your enjoyment. I freely admit to
reaching for the comics page(s) of the newspaper to read the latest antics of
Beetle Bailey, Dilbert, Hagar the Horrible, Garfield,
Dennis the Menace, Peanuts, Blondie, and many others.
As if that was not bad enough in some people's opinion, what would really keep me
from getting invited to any more high class dinner parties* if the word got out
is the fact that I actually try to spot the 6 differences in Bob Weber, Jr.'s drawings.
Melanie and I also like to work the
it up, wear it out, make it do, or do without" was more than just a clever slogan
during World War II. It was a way of life that extended to both civilian and
military realms. While civilians were being both encouraged and compelled to make
the most of what was available, military operations were scavenging, borrowing,
begging, confiscating, manufacturing, and
cannibalizing. France was an important center for not just resurrecting
battle-damaged Handi-Talkie and other types of radios, but for taking salvageable
components out of unrepairable units. The bit about grinding special crystals for
Skyworks Solutions today announced that a family
of groundbreaking diversity receive modules (DRx)
for LTE smartphones is currently ramping with several tier-one manufacturers. This
new product category leverages Skyworks' systems level expertise and techniques
developed for cellular base stations to create a highly innovative solution integrating
multiple low loss RF switches, receive SAW filters and LNAs
I have to admit to being
a bit surprised when creating this crossword puzzle featuring names of
editors from the RF and microwave industry's top shelf magazines.
In a couple instances I discovered some people I thought were editors are not anymore,
and some I did not know were editors now are. Clearly, I need to get out more. This
crossword commemorates the efforts of at least eight of those editors. If I remember
to do so, maybe next week's theme will be modern technical book authors.
was a distant memory for most people during the dark days of World War II.
Germany's forces launched its second siege of the 20th century against Europe in
Fall of 1939. By January of 1945, even the Brits were beginning to feel confident
that the seemingly endless days of World War II were about to come to an end.
Hitler's forces had been beaten back from its massive sprawl across Europe and into
northern Africa. Eisenhower's D-Day campaign six months earlier had broken
The November 2014 edition of ARRL's QST
magazine had a couple photos of some way-cool looking cakes decorated to look like
Ham radios. I figured there might be a few more out there so a Google search ensued
using "radio cake"
as the keywords. "Few" is not the most accurate word for describing the
humongous number of radio cakes that have been made. Below is a small sample of
specialty cakes you can find just in the Ham and antique radio categories. In
the electronics topics alone there are cakes styled after cellphones, computers,
telephones, boom boxes, alarm clocks, microwave ovens...
Algebra class just got easier
for high school math students with smartphones (ok, that
last part is redundant). PhotoMath is an app that uses OCR technology to decipher a polynomial
algebraic equation and perform operations on it - like solving for unknowns. microblink's
"Vision" app provides the OCR (blinkOCR) part of the
functionality since it already knows how to take a picture of text and convert it
to ASCII type characters based on its 'text recognition, barcode, and ID scanning'
algorithms. PhotoMath then takes the process a step farther by figuring out
what needs to be ...
guessing once word got out about the Fusite advertisement in the 1945 edition of
Radio News, there was a sudden surge of interest in buying electronics
magazines by young boys. Even by today's rather loose decency standards this
mermaid depiction would undoubtedly cause an outcry. Imagine my
shock in turning to page 90 and seeing this illustration! Why, I had to stare at
it for many minutes to believe what was before my tender eyes ;-) Of course
since RF Cafe is a family friendly website I did the responsible thing and blurred
the offending anatomical portion of Cincinnati Electric Products
announces an application note detailing the fundamentals of phase shifters including
theory of operation, critical parameters, and applications for test and measurement.
Telemakus offers USB controlled phase shifters covering 1-8 GHz with 12-bit
DAC resolution and greater than 400° of phase control. Models extending the
frequency coverage to 18 GHz are discussed. The application note outlines key
phase shifter parameters and how the Telemakus phase
"We do less with less,"
is what a senior engineer at a major defense electronics contractor once remarked
to me as he grew more and more infuriated with a malfunctioning antiquated component
specification database microfiche machine the company insisted on keeping in spite
of a modern computer-based alternative. Remember those frustrating contraptions?
That instance came to mind when I saw this white paper titled, "The Engineering
Workforce Problem: Doing More with No More." Since my last excursion to the TradePub
website they have added a lot of
with topics on PCB design that might be interesting
look at the circuit board and/or chassis of a radio set - new or old - you see a
lot of components including resistors, semiconductors (and/or
inductors, capacitors, transformers, switches , potentiometers,
shielded cables, shielded compartments, displays, indicator lights, connectors,
etc. With the possible exception of some semiconductors, the function of just about
every component can be discerned by most people who are at all familiar with radio
Communication Ground Segment and Earth Station Handbook, by Bruce Elbert, explores
the delivery end of the satellite link and its relationship to delivery of services.
From international telephone network gateways to direct broadcast home receivers,
today's broad range of ground systems and devices require satellite communication
engineers and business managers to have a broad and sound understanding of the design
and operating principles of earth stations and ground control facilities
This adventure of
Sherlock Ohms is useful to read because it demonstrates the
importance of finding the root cause of and truly correcting a problem rather than
stopping when a lesser solution that is merely a 'band aid' type cure would be easier.
The less desirable action would have been to de-rate the number of circuits that
could be serviced by each system since it was initially discovered that the problem
only occurred when the board count went above
others joke frequently about the promise of flying cars, automated homes, and miracle
pills to cure any ill that were predicted to be commonly available by the end of
the 20th century. Magazines like Popular Science, Mechanix Illustrated,
Science and Mechanics, et al, regularly printed stories about these and
a host of other inventions that were just around the corner. Most have never been
realized, but we're appreciative of the dreamers and those people who dedicated
their lives - often to the point of financial and/or physical ruin - while trying
to succeed. Taking a different approach,
Advanced Test Equipment Corp
is a nationwide company that focuses on the rental of a wide variety of equipment
working in a fast paced environment. We are looking for and experienced Calibration
Technician to calibrate, troubleshoot, and repair a wide variety of equipment, including
but not limited to: analyzers, GPTE, fiber optic, scopes, meters, power supplies,
in time for Halloween, John T. Frye's teenage sleuths
Carl & Jerry unexpectedly recorded a late-night conversation
between two men where they plot how to dispose of the 'body' when death occurred
as a result of prolonged choking. Employing their trademark technical prowess and
scheming ability, the pair sets a trap for the perpetrators and dutifully summon
the authorities as they complete their nefarious act of the night before. Halloween
comes into play because the recordings were made for
fairly ubiquitous in society these days for use in heating, radar, and even lighting.
They were probably the first useful means of producing high power microwave signals.
The concept was first brought to fruition in the early 1920s as a laboratory curiosity
and rapidly developed into a practical type of device with many applications and
spin-off products like the klystron, the traveling wave tube, and the cross-field
"For disappearing acts, it's hard to beat what
happens to the 8 hours supposedly left after 8 of sleep and 8 of work." - Doug Larson,
columnist. This appears in the 2015 edition of
The Old Farmer's Almanac. The article in which it appeared,
"Where Does the Time Go?," has a lot of anecdotal information about how long people
live, average sleep time, TV viewing time, work commuting time, pace of life, etc.
RFMW announces design and sales support for a
Ku-band SPDT switch capable of handling 5 W of RF power. The TriQuint
TGS4310 is a SPDT reflective switch fabricated on TriQuint's 0.15 um
GaAs production process. Operating from 13 to 19 GHz, the part handles +37 dBm
input power with <0.1 dB compression and less than 1.7 dB insertion loss.
The TGS4310 is available in a small 1.00 x 2.14 mm die size and requires very
little control current allowing for
While researching lab
wall charts last week, I happened upon a large collection of
comics on the Keysight website. They are clever puns on familiar engineering
themes, professionally drawn by artist
and very colorful. Permission for usage, presumably with proper attribution to the
source, is granted "For your lectures or in your labs." Screen savers are somewhat
passé these days, but if you are one who still sports such things, you can download
and radio facsimile machine electronics technology was credited for aiding in the
development of a new type of
scanning electron microscope (SEM)
that could image the surface of opaque object to a resolution of 100 Å.
The television contribution part of the technology was precisely controlling a raster
path for the electron beam. The facsimile part is the knowledge of how to assemble
a printed image from streaming data. It is interesting to note that in order for
an object to be imaged via SEM, its surface must be electrically conductive. Accordingly,
Here are another half dozen
schematics and parts lists for vintage radio sets. These are being
posted for the sake of the relatively few hobbyists who still take on the challenge
of restoring these old relics of yesteryear. I've finally resumed work on my
Crosley 03CB console cabinet radio. My nostrils are filled with
70+ year old walnut wood dust from doing the final sanding in preparation for staining
This week's engineering
crossword puzzle has a theme of
test equipment. The four longest words are types of test equipment,
and a few of the other are as well (or related to test equipment).
All the other words are from my hand-selected library of a couple thousand terms
related to engineering, science, mathematics, etc. Enjoy!
listen to a fair amount of radio and read news headlines throughout the day, so
I have heard and read a lot about the lurking Ebola epidemic. Like most RF Cafe visitors, I am at least as informed
on topics like viruses as the average citizen of the world. We know that there is
no 'cure' for a virus per se, just a possibility that it can be subdued by disrupting
its ability to replicate. Unlike bacteria which are cellular and have their own
support system, viruses require the metabolic mechanisms of a host in order to
will not find the name Central Intelligence Agency (CIA)
mentioned anywhere in this WWII era story reporting on the activities of the
Foreign Broadcast Intelligence Service, but it was then and is
now a branch of the CIA. Per the
CIA website "For nearly 70 years, the Foreign Broadcast Information
Service (FBIS) monitored the world's airwaves and
other news outlets, transcribing and translating selected contents into English
and in the process creating a multi-million page historical archive of the global
news media." Equally surprising is that the BBC
this week I posted a page pointing to the many laboratory wall charts offered by
Keysight Technologies. I mentioned how unlike modern charts that
are full of color, the old ones were usually a single color or black & white.
Here is an example from American Amphenol in the mid 1940s. Something like this
would make a really cool decoration for today. I just looked on eBay and didn't
Amphenol Tube Socket Wall Chart for sale, but that would probably
be the bet place to latch on to one eventually.
Website contributor Joe Cahak reminded
me of the Hewlett Packard Archive
website that is absolutely the go-to source for vintage HP documents. According
to the site's owner, Glenn Robb, there are more than 35,000 pages of Hewlett Packard
catalogs, Bench Briefs, product manuals, service notes, Watt's Current,
price lists, periodicals (Measure and Insight
magazines), journals, presentations, HP Test and Measurement News,
seminars, application notes, and much more ...
Joshua Fruchter, Esq., has posted an article that made me think
about how to a large extent the practice of law is a lot like writing HTML code
for a web page. Think of a lawyer as a programmer who writes his HTML code to produce
a specific output for a specific input. Codified law is analogous to the HTML specification
as published by the W3C. The judge and/or jury is equivalent to the browser creator.
As we all are painfully aware, even relatively simple web page code can end up displaying
vastly differently on not just browsers from various manufacturers
(Chrome, IE, Firefox, Safari,
It's time for another
round of RF & microwave articles from our industry's top tier magazines. Happy
Slot Antenna Tames 3 Wireless Bands
C. Jianzhong, P. Wenjuan
DARPA's Mobile Hotspot Program Drives E-Band
Cut the Defense Budget? Sure, No Worries,
Measurement of an Active Radar Module in a
Compact Antenna Test Range, H. Shakhtour,
D. Heberling, K. Noujeim, F. Gerhardes, P. Knott
Advantages of Propagation Path Replication for
Radar Range Testing, J. Mazzochette
Digital Technology is Removing the RF-to-Digital
Divide, Curtiss-Wright Defense Solutions,
Did I ever tell
the story about a manager I had at a major defense electronics firm who thought
he could make an NPN transistor by wiring two diodes in series with the anodes tied
together? He reasoned that since a bipolar junction transistor consisted of three
alternating layers of n-type and p-type silicon, the device could be affected per
his scheme. That was in the mid 1980s when I was still a technician
(working diligently on my BSEE degree at night). Needless
to say the engineers who worked under him were not too impressed with