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.
for the Experimenter
"Kink" is not
a word you hear very often anymore in reference to having a problem in a process
or task, but it turns up fairly regularly in hobby and do-it-yourself types of magazines
as "Hints and Kinks" columns. Having a kink in the neck or a kink
in the garden hose are more familiar uses of the word. "Kink" appears in QST, my
older model airplane magazines, in some of the Popular Electronics magazines, and
likely in many others. "Hints and Kinks" type columns typically are collections
of ideas submitted by readers explaining how they solved a particular problem or
how they came up with a new way of doing something. Some are outdated but many are
timeless in their application and usefulness. I put all the ones here in to the
"Wearable computing device,
comprising a wig that is adapted to cover at least a part of a head of a user, at
least one sensor for providing input data, a processing unit that is coupled to
the at least one sensor for processing said input data, and a communication interface
that is coupled to the processing unit for communicating with a second computing
device. The[sic] at least one sensor, the processing unit and the communication
interface are arranged in the wig and at least partly covered by the wig in order
to be visually hidden during use." That is the description of patent application
#20130311132 submitted to the USPTO by Sony Corporation on November 21st of this
year. Features include, but are not limited to, wireless communications from an
onboard microprocessor to...
Aug 1960 Popular Electronics
You have to be careful
when working this
crossword puzzle from the August 1960 edition of Popular Electronics
because in one instance the name of a certain federal agency has changed since then,
and in another instance the element cited as being "commonly used" no longer is.
It will add to the challenge, which, honestly, is not all that great. I did not
have the magazine page with the solution available when posting this so I had to
work the puzzle myself to create a solution.
Many years have
passed since I sat in a college classroom to learn about
transistor fundamentals. The industry had long moved past germanium
transistors and was solidly into silicon. Having been formally introduced
to transistors in the USAF, I was familiar with their functionality from a technician's
perspective of checking for gain, proper bias (as indicated on "educated" schematics),
and determining go-no-go health by performing a front-to-back resistance measurement
using an ohmmeter. Holes, energy bands, gate widths, and doping levels were first
encountered in solid state physics class, however. This article does a nice job
of introducing the terms and concepts at a layman's level. I actually found the
vacuum tube circuits in our radar unit easier to troubleshoot than transistor circuits,
partially because I had a little experience with them prior to enlistment and also
because the point-to-point component mounting made it easy to isolate or remove
Multiphysics FEM EM Solver
AWR Corporation, the innovation leader in high-frequency
EDA software, announces the release of v11 Analyst-MP™ -
multiphysics finite element method
(FEM) electromagnetic (EM) analysis software. Analyst-MP is an application-specific
product offering from AWR that leverages the capabilities within its Analyst™ 3D
FEM EM simulation and analysis software while targeting big, multiphysics applications
like particle accelerators. Analyst-MP's diverse and unique solver technologies
are the result of more than a decade of development in collaboration with the U.S.
1960 Popular Electronics
a fool, many years ago I donated a perfectly fine
vacuum tube tester that had been given to me by an über-engineer/ham
I worked with during the time (nearly 30 years ago) I was restorating my first vintage
tube radio. Bad move. It was a really nice tester: a B&K Model 650 Dyna-Quik
Dynamic Mutual Conductance Tube & Transistor Tester. It was sold shortly after
I had also given away as a wedding gift the Crosley floor console radio that I restored.
Another bad move. Now, many moons later, I am working to restore yet another Crosley
tube radio and I sure wish I had held on to it. Similar tube testers are routinely
selling on eBay for $100-$200. At some point I'll buy another tube tester, maybe...
for Doppler Radar Systems
PMI Model No. PIFA-9D4G-1D8G-1 is an
integrated frequency down converter used within Doppler Radar Systems. The
RF Input is 9.4 GHz ±30 MHz with an input dynamic range of 100 to 0dBm.
The LO Input is 2.803 GHz ±15 MHz with a power level of +5 to +7 dBm.
The resulting IF Output Frequency is 1.8 GHz ±10 MHz. The RF to IF
gain is 10 dB to 13 dB. This module incorporates internal RF, IF
and LO filtering and amplification for optimum out of band rejection. Group delay
ripple from RF to IF Output is less than 0.1 ns over a 20 MHz bandwidth.
in Appreciation of Support
Vector Telecom has fully instrumented microwave,
millimeterwave, antenna laboratories and production facilities. A wide selection
of waveguide straight and curved plumbing sections,
couplers, dividers, attenuators, circulators, terminations, and rotary joints are
available. Their professional engineers have backgrounds from telecommunications,
electronics, space and aviation industries. Frequencies up to 50 GHz, at globally
competitive prices. Custom designs available.
Unless you use
on a regular basis, you might be inclined to wonder why someone wouldn't simply
use a computer, tablet, smartphone, etc., for routine calculations. After all, the
software available for and the computational power of even a nothing-special computer
greatly outperforms the most powerful handheld calculator, right? The simple answer
is that when you are working in a confined space as is often the case at a classroom
desk or in a research and development lab, finding a place to sit down and use a
notebook or tablet computer can be challenging. There is also an advantage in having
a device specially built with a custom ASIC and populated with optimized software
that covers a wide range of computational...
Skyworks Solutions, Inc. introduces a µSwitcher™
for space-constrained, portable applications including Bluetooth® headsets, smartphones,
digital cameras, hard-disk drives, portable media players and other battery-operated
handheld computers/peripherals. The SKY87250 is a highly efficient, low-supply regulator
with integrated inductor housed in a compact package. Given its ultra-small footprint,
integrated inductor and capacitance, the converter is easy to design in and requires
very little support.
RF Circuits and Nonlinear Vector Network Analyzers: Interactive Measurement and
Design Techniques, by Patrick Roblin. "With increasingly low-cost and power-efficient
RF electronics demanded by today's wireless communication systems, it is essential
to keep up to speed with new developments. This book presents key advances in the
field that you need to know about and emerging patterns in large-signal measurement
techniques, modeling and nonlinear circuit design theory supported by practical
examples. Topics covered include large-signal measurement techniques that have become
available with the introduction of NVNAs, direct extraction of device models from
large-signal RF dynamic load lines, X-parameters and more.
We have long
known that activity on our sun affects electromagnetic communications. Energetic
particles, primarily electrons, explode from the sun's surface (coronal mass ejections
and flares) and are hurled at blazing speeds towards the earth at an
speed of around 424 km/s (263 mi/s). They begin affecting our upper atmosphere
about four days later by ionizing atoms, thereby altering electrical conduction
properties. This in turn determines how and whether electromagnetic signals either
pass through the atmosphere into space or get refracted (bent) back down toward
Earth. Long distance communications in particular are effected, but often even local
communications are impacted as well. Some events have little effect, some cause
for Continued Support!
For over 40 years
KR Electronics has designed and manufactured high quality
RF and microwave filters for the commercial
and military markets. KR Electronics manufactures all filter types and individually
synthesizes filters for special applications. State of the art computer synthesis,
analysis and test methods are used to meet the most challenging specifications for
all standard filter types as well as linear phase, constant group delay, video,
sin(x)/x, root & full cosine, pulse & step response, and nearly any custom
Handsomely from Student Loans
Government profited $41.3 billion on student loans in fiscal year 2013, down $3.6
billion from 2012. That's good news, right, the government making a profit on something
for a change? Yes, except for one major fact: The
business was completely stolen by the Fed from private lending institutions
in 2010. Wouldn't it be nice if you could simply seize control over an already profitable
industry and claim it as your own? Venezuela has been doing that a lot lately. If
you or your child is a student who needs money for school, you now have one place
to go; that evil free market greed by companies harboring an evil
profit motive have been removed from the equation. Oh, wait... What is not factored
into those numbers...
from Space Station (ISS)
Is this a
cool photo or what? Shown are three student-built Cubesats being deployed from the
end of the International Space Station's (ISS) robotic arm. The shape of the launch
mechanism reminds me of a 3-pin, single row Molex or Amp (like used on you PC's
hard drive) power connector. "The
is an international collaboration of over 40 universities, high schools, and private
firms developing picosatellites containing scientific, private, and government payloads.
A CubeSat is a 10 cm cube with a mass of up to 1.33 kg. Developers benefit from
the sharing of information within the community. Resources are available by communicating
directly with other developers and attending CubeSat workshops."
- Eugene Wigner -
Unreasonable Effectiveness of Mathematics in the Natural Sciences" - title of article
by theoretical physicist and mathematician
Eugene Wigner. It is part of the title of his book (out of print), The Unreasonable
Effectiveness of Mathematics in the Natural Sciences, in Communications in Pure
and Applied Mathematics, vol. 13, No. I (February 1960),
John Wiley & Sons.
Some of these offerings are sample chapters from books while others are stand-alone
resources from TradePub. I
make a few pennies (literally) off each item you download. The price you pay is
giving them your e-mail, but to date I have never had a complaint. Thanks.
Resumes for Dummies, 6th Edition - Free Sample
Cover Letters for Dummies, 3rd Edition - Free
Job Interviews for Dummies, 4th Edition -
Free Sample Chapter
10 Tips and Techniques For More Effective
Photoshop CS6 Unlocked: 101 Tips, Tricks, &
Techniques - Free 61 Page Preview
Wiley's Career Book Bundle - A Free 207 Page
For the sake
of avid cruciverbalists, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics,
chemistry, physics, and other technical words. You will never be asked the name
of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Enjoy!
If you are an audiophile,
you probably have spent a lot of effort setting up your home entertainment system,
car system, and maybe even your portable music player. You know all about how to
select speakers, where to place them, the kind of wire and connectors to use,
treble, midtone, and bass equalization. You know what you like, but the way you
perceive sounds is not the way many other people do. Even if your hearing follows
a 'normal' response curve per
standardized audio tests, personal preferences vary widely in
part because the way brains are wired (speed of sound processing, preferred musical
style, state of mind - maybe you're insane) and in part because of the impact of
sound waves upon your body (soft tissue and bone pressure wave conduction, clothing
worn). Pitch, timbre, tone, and loudness has been extensively studied and quantified.
While three of the four are purely objective measurements...
husband wants a selenimum rectalfire, a silicode capasitator, and a 16 bome appleflyer."
That is the caption of one of the "Hobnobbing with Harbaugh," comics that appeared in the June 1962
edition of Popular Electronics magazine. "Hobnobbing with Harbaugh" was
a monthly feature for a couple years that dealt with stereotypical (pun intended)
behavior of technophiles and their often unwilling, often unwitting wives, girlfriends,
kids, parents, workmates, and neighbors.
Microwave for Support
has helped deliver RF Cafe since 2009. "We provide a wide range of high quality
RF and microwave products with quick
delivery time at very competitive low prices. Our products include coaxial connectors
and adapters, circulators, isolators, low noise amplifiers, power amplifiers, broadband
amplifiers, terminations and more, covering the frequency range of 100 MHz
to 110 GHz. We also provide technical consulting services and engineering contracts
which include antenna design, electromagnetic structural analysis, and low cost
manufacturing of RF/microwave circuits and systems."
for November 2013
For your professional edification
and reading enjoyment, I suggest the following from MW&RF, EDN, and MPD Digest:
Check for Co-Existence
Between LTE and Radar,
by Greg Jue
So You Think You
Lines, by Eric Bogatin
in Spectrum Analysis,
by Bob Nelson
EDA Software for
by Stephen Maas
the Role of Local
Phase Noise in
by Dale Henkes
& Science Doodles
Do you remember seeing a cool
Doodle on the Google search page and would like to find it again? Would you like
to see not only the Doodle that piqued your interest, but ALL of the Doodles that
Google has ever published? You can do that, but what might be more useful would
a page full of all the technology- and science-related Doodles or some other specific
topic. Fortunately, there is an easy way to find what you want by going to the Google
website and typing "google doodles" into the search box. Once you get there, enter
the specific event that interests you. Doodles have been created to commemorate,
among other topics, Robert Noyce's Birthday, the Large Hadron Collider, and the
Invention of the First Laser. Some, like the 25th Anniversary of the Buckyball,
are animated. If you happen to be interested in seeing the Google Doodle for Canada
Day , Bruce Lee's 125th Birthday , or Thanksgiving Day - all worthy Doodles
- then add the name of your sought-after...
as an Advertiser !!!
Excel-Wireless is a solution provider with
many years of experience in the cellular
amplification and wireless communications industry, serving private companies,
universities, military and government agencies. Cellphone signal boosters, antennas,
cable assemblies, and WiFi/WLAN network equipment are among our offerings. We stand
behind our products offering full service warranty, return and replacement, and
installation support. We can produce up to 10,000 pieces of different cable
assemblies every day. Not many factories can do that!
for Continued Support!
Innovative Power Products has been with RF Cafe since early 2008.
Innovative Power Products has more than 25 years of experience designing and manufacturing
RF Passive Components. Our RF couplers, combiners,
resistors, and terminations incorporate the latest technology in materials available,
which equates to unrivaled product performance. Please call 1-631-563-0088 to speak
to an experienced Design Engineer about your upcoming project.
cannot buy this amazing
Chart of Electromagnetic Radiations anymore, but thanks to the
folks at Lawrence Livermore National Laboratory, extremely high resolution image
files of it have been placed on the flickr website. The chart showed up in Popular
Science magazine recently. W.M. Welch Manufacturing Company originally sold the
wall poster in 1944, so the content does not reflect knowledge gained in the last
seven decades, but its sheer artistic beauty and amazing content is enough to bring
a tear to a technophile's normally staid eye. Even if you do not print out and hang
it on your office wall, you owe it to yourself to at look at the 10000x6958-pixel
from IEEE JobSite
time I have some items from the IEEE JobSite newsletter for you, in case you are
not a subscriber.
The No. 1 Reason
Employers Can't Find the
Work-Life Law Coming to
City Near You
How to Make Your Resume
or CV Age Anonymous
Asia-Pacific – Open
Business, and Tech
have to admit that when I saw this large advertisement for the
Sarkes Tarzian company in Radio & TV News, I didn't
recall ever having heard of the company. According to Wikipedia, "Sarkes Tarzian
(1900-1987) was an American engineer, inventor, and broadcaster... He attended the
University of Pennsylvania and received an undergraduate degree in 1924 and a graduate
degree in 1927. Tarzian worked for the Atwater Kent company and then for RCA...
He founded the manufacturing company Sarkes Tarzian Enterprises in 1944, and was
involved in early experiments in VHF audio broadcasting in 1946... In 1949 he started
television station WTTV...
Microwave Technology !!!
Technology is the newest company to join supporters of the RF Cafe website. Without
their backing, RF Cafe would not exist. Please show your appreciation by taking
a moment to visit Agile Microwave Technology's website to see whether they might
be of use to your project for RF amplifiers,
switches, limiters, multipliers and mixers up to 40 GHz. "Our founders
have over 100 man-years of experience designing, developing, manufacturing, marketing
and providing innovative solutions to the industry. Higher Performance at Lower
Cost through Innovative Engineering."
to Ford and Chrysler aficionados for not having similar articles for your classic
automobiles, but this article from a 1957 edition of Radio & TV News
Chevrolet radios. Maybe someday I will acquire editions with other
models. Transistors were fairly recent newcomers on the portable radio scene (on
any radio scene for that matter), so you will please excuse the absence of them
in most radios of the era. In fact, as evidenced by a companion article in this
same edition titled "Delco's All-Transistor Auto Radio," such newfangled devices
like transistors were reserved for top-of-the-line models like Cadillac's Eldorado
Brougham. A move toward printed circuit boards, rather than the time-honored point-to-point
wiring, was well underway, and push-button tuning was being sold to the car buying
public as an indispensible safety feature - the "hands-free" feature of yesteryear.
Even though push button tuning with memory (albeit mechanical) for storing station
locations had been around for a long time in tabletop and floor model console home
are a few worthwhile new news stories from the IEEE USA's today's engineer
Key to Unexpected
Egos in Action:
My Idea is
Way Better Than
Why Do Managers
a Skills Gap Exists?
High-Frequency Module Design
AWR Corporation offers the second in a series
of white papers addressing RF/Microwave design flow issues. This latest offering,
"EDA Software Design
Flow Considerations for the RF/Microwave Module Designer," outlines the steps
for implementing an integrated design flow within the Microwave Office® design suite
for an MCM microwave monolithic integrated circuit (MMIC) design. This white paper
is a follow on to "RF/Microwave EDA Software Design Flow Considerations for PA MMIC
Design," which examines GaAs pHEMT PA design approach from a systems perspective
Civil Air Patrol (CAP), being made primarily of volunteer, unpaid
airmen and officers, has been serving the country since World War II. Many
members use (or at one time used) their own aircraft and radio gear in the service
of the country. Per the CAP website, "In the late 1930s, more than 150,000 volunteers
with a love for aviation argued for an organization to put their planes and flying
skills to use in defense of their country. As a result, the Civil Air Patrol
was born one week prior to the Japanese attack on Pearl Harbor. Thousands of volunteer
members answered America's call to national service and sacrifice by accepting and
performing critical wartime missions. Assigned to the War Department under the jurisdiction
of the Army Air Corps, the contributions of Civil Air Patrol, including logging
Fundamentals of RF and Microwave Transistor Amplifiers,
by Inder Bahl. "This book provides state-of-the-art coverage of RF and microwave
transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power,
high-efficiency, and high-voltage. Topics covered include modeling, analysis, design,
packaging, and thermal and fabrication considerations. Through a unique integration
of theory and practice, readers will learn to solve amplifier-related design problems
ranging from matching networks to biasing and stability. More than 240 problems
are included to help readers test their basic amplifier and circuit design skills-and
more than half of the problems feature fully worked-out solutions...
electronics analogy quiz is a little easier than a few of the
others published in Popular Electronics because all of the electrical and
mechanical objects depicted here are very familiar. The concepts might seem trivial
to those of us who have been immersed in the science for decades, but I for one
can remember when first hearing these analogies how helpful they were. Not only
that, but I also recall during physics and mechanics courses in college being amazed
at the similarity of equations shared by electrical and mechanical processes.
A Carl and Jerry Adventure
"The River Sniffer," our intrepid sleuthing heroes
Carl and Jerry apply their electronics prowess and lessons remembered
from chemistry class in order to catch polluters who are dumping chemicals into
the river where they like to fish. I always like being reminded of something long
forgotten when reading an article, and this one did not disappoint. Do you recall
what 'pH' stands for as a measure acidity or alkalinity? It means 'potential
Hydrogen ion concentration.' Don't thank me if it jogged your memory
as well - thank Carl and Jerry.
am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under
the second law of thermodynamics, steeped in the steam tables, in love with free-body
diagrams, transformed by Laplace, and propelled by compressible flow." -
(I had forgotten about free-body diagrams in Statics class!)
from Your Military Unit
If you are getting
nostalgic in your old age and want to reclaim some of your past military duty history,
one possible venue is eBay. A fellow USAF radar shop technician recently wrote to
ask if I would be willing to part with one of my
5th Combat Communications
Group (aka 5th Mob) patches as displayed on my web page dedicated to the radar
shop at Robins AFB, Georgia. Since I only have one of each patch, I decided to look
on eBay to see what might be available, although admittedly with little expectation
that any of the patches would be show up. To my surprise, not only were patches
available, but other kinds of paraphernalia like basketball team jerseys (I didn't
know the 5th Mob had one), coffee cups, pens, hats, and other stuff. I had
no idea that there was an Association of Old Crows (AOC) patch for Robins Air Force
Base. If I can...
Crossword for 11/17/2013
break and work this week's
microwave engineering themed crossword puzzle. All the words are
pulled from a hand-built list of terms, names, and abbreviations that have only
to do with science, mathematics, and engineering. If you want a crossword with names
of movie stars and obscure countries, try the local newspaper. If you want to exercise
your nerd knowledge, this is the one for you.
Almost without exception when there is a breaking
news story about some schmo being arrested for committing a crime, reporters find
neighbors who say they were taken totally by surprise because the accused is such
a nice guy and keeps to himself, volunteers at the food pantry, etc. There was never
any sign that the guy (or gal) might be on the verge of robbing a bank, embezzling
church funds, or kidnapping a couple neighborhood children. It has happened often
enough that I have adopted the philosophy that you can never really know someone
unless you live with him/her for a long time and are aware of all activities. Such
a surprise happened to Melanie and me a few days ago. The dentist we have...
RBO-2 Radio Restorations/p>
visitor and occasional contributor Gary S. just sent me photos of two fine
looking vintage U.S. Navy radios that he restored to working order. The condition
of the front panels on both radios is amazingly good. Here is Gary's Tale of
Two Radios. "I thought I would share with you my latest refurbished WW-II Navy
receivers I acquired last spring. I say refurbished because I do what repairs are
needed to get them operational again and then clean them up a bit. I consider
a restoration to mean made to work and look like new again using original parts
if they are available. The first receiver is the
Hammarlund RBG-2 general coverage HF communications receiver.
It covers from 540 kc to 32 mc. They didn't use Hertz in those days. It is
basically an HQ-120X beefed up to Navy specs...