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.
Please Welcome Triad RF Systems
Triad
RF Systems just signed on with RF Cafe as an advertiser and
supporter of the website. They are a small, private company run
by serial entrepreneurs, offering tower-mounted amplifiers, unmanned
aerial vehicle (UAV, aka drone) amplifier systems, and many standard
(30 - 6,500 MHz, up to 200 W) and custom-designed amplifier subsystems
to your specifications.
Surfing at 560 M.P.H.
Here
is an interesting graphic published in the New York Times that illustrates
how Internet connections
in high-speed commercial aircraft manage to function reliably. I
have never tried using the Internet on an airplane. Anyone care
to comment?
The Future of Predictive Coding - Part II
But
wait, there's more.
IMS
ExpertServices' lawyer Maggie Tamburro just published
The Future of Predictive Coding (Part II) – Caveats Revealed,
a continuation of her original article. At issue is whether predictive
coding can be presented as an "expert" in court cases. Essentially,
if I read this correctly, it would permit a computer algorithm that
predicts future behavior to be admitted as evidence on par with,
say, a human psychologist. The argument for predictive coding is
that its criteria are selected by and code is written by humans
and is therefore not a Hal (2001:
A Space Odyssey) scenario. Neither is it absolutely reliable.
Is it admissible for demonstrating intent to commit - or not commit
- a crime? What we have is more akin to
Minority
Report than to 2001...
RF & Microwave Webinar
Wireless
Site Survey Using a Handheld Spectrum Analyzer, by Agilent Technologies,
Wednesday, July 11, 1:00 pm EDT
VIP's Are Hams Too!
What
do General Curtis LeMay, Arthur Godfrey, Herbert Hoover, Arthur
Collins all have in common? They were Ham radio operators. A lot
of famous people were/are Hams, with these and a few other notables
mentioned in this March 1958 edition of Popular Electronics. Conspicuously
missing is one of modern day's most renowned Hams, and that's Walter
Cronkite, KB2GSD (died in 2009). His broadcast career stretched
back to World War II, so he was definitely around long enough. Maybe
the author just didn't know; after all, he couldn't...
DJIA Chart Back on RF Cafe
A
couple years ago the DJIA market thumbnail chart I had at the bottom
of the page stopped working (it is a
Google Gadget), so it was removed. It is finally, it is working
again, so it's back at the bottom. Now you have more reason than
ever to keep returning to RF Cafe ;-)
Hallicrafters SCR-299 Mobile Radio in WWII
The
definition of "mobile," at least as it pertains to battlefield communications,
has changed significantly since this Hallicrafters
SCR-299
radio was developed during World War II. The SCR-299 is an adaptation
for battlefield use of what began life as a transmitter for amateur
radio operators. Ruggedization of the entire unit was performed
by factory engineers to ensure it would survive the rigors of rapid
deployment
over hill, over dale, as the soldiers hit the dusty trail. RF
Cafe visitor Paul A. recently sent me a link to this video documentary
produced by Hallicrafters showing the SCR-299 being used in the
field as well as some cool factory factory production footage. Often
when I am looking at an old house, or car, radio, or airplane, I
envision the people who were alive at the time, putting the lathe
and plaster on the walls of a home, or wrapping the paper-dielectric
capacitor lead around the post used in point-to-point wiring of
a radio, or maybe installing the seats in a vintage car - nameless,
faceless...
Play Games with Nixie Tubes
Nixie
tubes were used for numeric - and sometimes alpha - displays back
in the days before LEDs and LCDs. They were more light bulbs than
tubes, but were encapsulated in evacuated glass shells like vacuum
tubes and had round, multi-pin bases like tubes. Separate filaments
were provided for each character. There were tow basic varieties:
characters that displayed through the top of the tube, and
characters that displayed through the side of the tube. Supposedly
the name "Nixie" derived from "NIX I", an abbreviation of "Numeric
Indicator eXperimental No. 1," as designated by the Burroughs Corporation
sometime around...
Wireless Themed Crossword -7/8/2012
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., Lamar)...
Homebrew Wooden Cellphone
MIT
PhD candidate David Mellis has recently achieved fame for his custom
designed and built cellphone. $150 worth of cobbled-together parts
got him a GSM phone
with an 1.8″ color , 160×128 pixel, TFT screen. He used a clever
way of forming the pressable buttons in the plywood cover. Digi-Key
must be happy with the unintended product placement opportunity
in this picture of
David and his companion trying out his wooden phone.
What Is the Higgs Boson?
Employees
of Wonderful Motherboard took to the streets of Brooklyn, NY, to
ask people what they know about the Higgs Boson. The responses are
about what you might expect. One of my sisters asked me yesterday
what the Higgs Boson is.
My answer was that it is basically the "equals" sign in Einstein's
famous e=mc2 equation. You can quote me on that one.
Notable Quote
"Successful technology is invisible. It gets out of the way and
lets us live our lives." -
Amber Case of Geoloqi (Jul/Aug 2012
Inc.)
Featured Book - Silicon Valley History
An
Alabama Boy and the Birth of Silicon Valley: The Autobiography of
Ernest Jerry Collins - by Ernest Jerry Collins
"Few people would expect that someone born in the small town
of Gadsden, Alabama during the Great Depression would end up being
involved in everything from the US Navy to the Atlas II ICBM missile,
but Ernest Jerry Collins did just that..."
Featured Book - Silicon Valley History
An
Alabama Boy and the Birth of Silicon Valley: The Autobiography of
Ernest Jerry Collins - by Ernest Jerry Collins
"Few people would expect that someone born in the small town
of Gadsden, Alabama during the Great Depression would end up being
involved in everything from the US Navy to the Atlas II ICBM missile,
but Ernest Jerry Collins did just that..."
The Capacitor: What It Is, What It Does...
Here
is a very nice primer on capacitors that appeared in the April 1960
edition of Popular Electronics. A lot of ground is covered including
history, form factors, dielectric types (ceramic mentioned as a
new variety at the time), applications, etc. Interestingly, units
of picofarads were still being referred to as μμfarads. In fact,
since not a lot of work was being done yet in the GHz realm, there
was not much use for pF other than maybe to tune a filter response.
The author reveals a sense of humor when writing of early capacitance
experiments as he says...
Find the Brightest Bulb
Here
is a nifty little exercise that appeared in the April 1960 edition
of Popular Electronics. It has 10 different light bulb circuits
and challenges you to figure out which bulb would burn the brightest.
All are intuitively obvious to most of us who have been in the field
for decades, but do you remember how to do a circuit mesh analysis
to prove your "gut," as the Donald would say? If you resort to building
any of...
10 Minutes of Your Time, Please
Here
in America, July 4th is when we celebrate our
Declaration of Independence.
Please take this time to read it in its entirety. The delineated
wrongs of King George III ring chillingly familiar as applicable
to the government we have today: Refusal to assent to laws, forbidding
his governors to pass laws of immediate and pressing importance,
obstructing the laws for naturalization of foreigners. Yes, it's
all in there...
Operate and Release Times of Relays
The
April 1967 edition of Electronics World had a series of articles
on designing systems with electromechanical relays. Even in today's
high solid state relay world, there are still lots of applications
for electromechnical relays. Only a handful of people actually design
them, but the application tutorials provided therein are as valuable
to today's engineers and technicians as they were 45 years ago...
Average Engineering Wages
Many
of the major engineering magazine websites publish annual salary
survey results that have polled their readership. They always provide
numbers explaining how they arrived at their charts, but in the
end, those might not represent a true cross-section of salaries
since they only represent people who bothered to participate. Maybe
the type of person who fills out surveys tends to bias the results
upward or downward. Those polls also usually include participants
from other countries, with salary information being converted to
U.S. dollars (although often separate charts are included showing
the distribution of data by country. Still, I am never quite sure
of what the numbers really mean. Since I am not sophisticated enough
to collect my own statistics, instead I went to the website of the
U.S. Bureau of Labor Statistics to get their latest numbers (as
of May 2011) for incomes of all wage earners. Salaries used here
are from the "Average...
The Future of Predictive Coding
Every
month or so the good folks at
IMS
ExpertServices sends me an article written by one of their legal
beagles (aka lawyers) reporting on court high tech cases that are
of interest to RF Cafe visitors. They all involve use of Expert
Witnesses. Here's an excerpt from this one titled
The Future of Predictive Coding: "Like a dog chasing its
own tail, technology has been forced to generate new solutions to
deal with the escalating costs and burdens associated with legal
review of massive amounts of electronically stored information..."
New Radar Shop Troop Checks In
Please
welcome fellow USAF radar technician
Tony Spagnolia to
my honored list on the AN/MPN-14(13) ASR/PAR Mobile Radar Shop web
page. If you or anyone you know is a former radar tech, please contact
me and I'll be glad to add you...
Bayliss Transformers Advertisement
This
advertisement for transformers, coils, chokes, and rotary converters
from William Bayliss Ltd., on Sheepcoat Street in Birmingham, England,
appeared in the March 9, 1932 edition of The Wireless World. For
those not familiar with it, The Wireless World was the UK's premier
electronics magazine of the day...
Free Engineering Magazine Subscriptions
Most
of the "important" technical magazines offer you a free subscriptions
if you are qualified - often that means you still have a pulse.
Their advertisers pay according to circulation, so higher subscription
numbers
mean higher sales prices for them. A few of the most useful for
us are
Electronic Design,
Microwave Engineering Europe,
Military & Aerospace Electronics, and
Microwave Product Digest (lots of
good articles). There are a couple hundred
magazines
and white papers to choose from (I
make about $1 on each one you subscribe to)...
Microwave Themed Crossword -7/1/2012
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., Lamar)...
No Space Between Number and Units
In
the last year, there has been a trend to forego the space between
numbers and units in product datasheets and in press releases. Not
only does that practice violate a centuries-old standard, but it
creates an opportunity for misinterpretation. I actually asked a
couple company communications people why they are doing that and
they say it is to prevent units and numbers from being separated
as a line wraps on the screen. I mentioned that the non-breaking
space symbol (HTML   or ), aka hard space
or fixed space, can be inserted...
Featured Book for Entrepreneurs
Street
Smarts: An All-Purpose Tool Kit for Entrepreneurs, by Norm
Brodsky and Bo Burlingham. Every month I look forward to reading
Norm Brodsky's sage advice to small business owners / entrepreneurs
in Inc. magazine's
Street Smarts column. The nut of his philosophy to crunch the
numbers and make business decisions accordingly just as the big
companies do. Otherwise, those who do will run right over you. OK,
so now I know what to do; I just have to do it.
RF Absorbent Material (RAM) Chart
Emerson &
Cuming has a really nice chart available for determining the dielectric
constant and loss tangent. It includes materials that they supply
as well as for some other common materials. JP-4 fuel, various types
of rubber, silica, beryllium oxide, pure water are amongst those
included on the chart...
Nobel Prize "Medal Migrations"
According
to a survey done by Scientific American
(July 2012), there has been a
majority shift of Nobel Prize awards from European recipients to
American recipients. The author cleverly titles the article "Medal
Migrations" (metal migration - get it?).
This would make me proud as an American except that I know the selection
process has been greatly politicized. The graphic also includes
trends in awards according to gender and age
(average age increasing significantly,
youngest is 25 years old, oldest is 103!). The institution
with the most affiliated members...
Notable Quote
-Archive-
"In the surreal world of student loans, the brilliant student
completing an electrical engineering degree at M.I.T. pays the same
interest rate as the student majoring in ethnic studies at a state
university who has a GPA below 2.0." -
Richard Vedder, Professor of Economics, Ohio University
RF & Microwave Webinar
-Archive-
MSR Base Station Introduction and Measurement Challenges, by
Agilent, Thursday, June 28, 1 pm ET
Ultra-Portable Cellular Networks for Next Generation Warfare,
by Military & Aerospace Electronics, Thursday, June 28, 2:00
PM EDT
Among the Novice Hams - Nov 1957 PE
As
with on my
Airplane
and Rockets hobby website, a big part of my motivation for scanning
and posting these vintage electronics magazine articles has been
two-fold. The first reason is to provide access to historical documents
for educational reasons. The second reason is to have the names
of people and places published in text format (everything OCRed)
so that someone doing a Web search for himself, a relative, or a
friend, might run across it here...
Pop'tronics Comic Strip Electronics
The
1950s was a time when futurists were predicting that domestic robots
would be common place items in households. By the turn of the century,
mankind, freed from the drudgery of manual labor, would have plenty
of time for recreating, resting, and sitting around brainstorming
the next big thing. Here it is 12 years into the new century and
at the most, a fraction...
Crossword from 1957 Popular Electronics
Here
is a 1950s vintage crossword puzzle from Popular Electronics. Unlike
the weekly crosswords from RF Cafe that uses only relevant technical
words, this one fills in with common words. It's still a good puzzle.
CITE City: A Planned High Tech Ghost Town
When
you think about a ghost town, visions might be invoked of a deserted
Old West town where Wyatt Earp could have passed through, or maybe
you think about a recent news story of one of the empty - or nearly
so - newly constructed towns in some areas of China where a slowing
economy has put big plans on hold. Believe it or not,
there is a group of investors here in America that plan to construct
an entire 15 square mile city from the ground up, complete with
high-rise buildings, a shopping mall, urban areas, suburbs, an airport
and bus terminal, train tracks and paved roads, trees and parks,
water and wastewater facilities, an electrical grid, and virtually
everything else you would expect to find in a typical 20th century
city with a population of around 35,000, but nobody will ever live
there. People would only complicate matters by necessitating planning
for and compliance with crippling regulations and accommodations.
It sounds like the dream of a serious misanthrope. In reality, it
is the perfect environment for conducting large scale systems testing
on everything from wireless communications, to computer networking...
Life @ RF Cafe
More
than a few people asked why we moved from North Carolina to Erie,
Pennsylvania, back in 2008. This photo at least partially answers
the question. The view is from the back porch of
RF Cafe HQ.
Radio on Postage Stamps
Over
the past many decades, my involvement in stamp collecting (philately)
has waned and ebbed with the amount of time available to dedicate
to it. Commemorative stamps - from all countries - have always been
of the greatest interest to me. Even if you are not a cruciverbalist,
your interest in radio should be piqued by the large number of postage
stamps that have been issued in radio's honor. Although I do not
own most of the stamps pictured here, there are some that are in
my collection. This is a small cross-section...
The Case of the Morse Code Oven Latch
In
the May 2012 edition of QST, "Hands-On Radio" column author H. Ward
Silver has an article titled, "RFI Hunt." It is a very interesting
saga of discovering, then troubleshooting, then correcting a very
strange and unlikely issue. In a nutshell, Mr. Silver installed
a new 105-foot dipole antenna about 30 feet over his house and,
unbelievably, when he operated CW at 30 or 40 meters (at 25 W or
higher), the door safety latch on his self-cleaning oven would energize
during the dot or dash transmission. He works his way through many
iterations of line chokes, bypass capacitors...
Radio Tech Positions @ U.S. Capitol Police
Installs/maintains
a wide range of radio equipment and system components, including
VHF repeaters (conventional and trunked), combiners, duplexers,
filters, power amplifiers, UPS, and antennas. Sets up and installs
ad hoc radio networks (repeaters, receivers, duplexers, base stations,
and connectivity) at off site locations in support of USCP travel
missions...
Science Themed Crossword - 6/24/2012
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., Lamar)...
Angel Flight Video
Angel
Flight" is the unofficial designation given to aircraft transporting
fallen military members back to the USA for burial. Country songwriter/singer
Radney Foster
came up with a piece by that title. The video presented here is
not the one posted on his site as the "official" version; this one
is a remix that has the words superimposed (and there is no advertisement
in it - yet). We're fast approaching...
Dave Coverly Tech Comics
Dave
Coverly (SpeedBump.com)
is an artist who frequently does tech-themed comics for newspapers
on topics like cell phones,
math,
science,
electronics, etc. Here are a few that I think are particularly clever.
Tech Blunder in "Air Force One" Movie
Melanie
and I were watching Air Force One (Harrison Ford) the other night
and there was a scene where the Prez was in the bowels of the 747
and had to jerry-rig some wiring to dump fuel. He used a butter
knife to easily strip the insulation off the wires. I know from
having built MIL-SPEC and aerospace harnesses that only Teflon...
Notable Quote
-Archive-
We prefer not to call people 'seats.'" --
Jason Fried, re enterprise software applications
Featured Book
Load-Pull
Techniques with Applications to Power Amplifier Design,
by Fadhel
Ghannouchi, Mohammad Hashmi
Beware Yontoo Virus
Yesterday evening, Melanie alerted me that on her computer an
ad for a search company called Contenko was appearing on her web
pages where Google Ads and other 300x250-pixel image ads would normally
appear. She wondered if the problem was with something gone awry
on RF Cafe, because that's where she first noticed it. I immediately
suspected a virus and confirmed something was up after verifying
that the page source code was presenting the proper images. A quick
search revealed that a piece of software by Yontoo is being distributed
with some downloadable software that is capable of hijacking image
space and displaying its own content. It is not officially a virus,
but in my book it certainly is a virus. It, without permission,
usurps real estate on any web page and attempts to steal potential
profit. In my case, I have RF component companies that pay to rent
public space on RF Cafe web pages so if some piece of shite company
decides to display their products there instead, it denies my advertisers
a chance to get business. This phenomenon is not unique to RF Cafe;
it does its dirty deed on any website. I suspect the software installed
with a program that Melanie downloaded for her violin and cello
playing since the date in the Windows Control Panel's Add/Remove
area coincides (might want to check your).
These things always make me reflect longingly on the story of a
major hacker in Russia discovered with a ball peen hammer buried
in his head.
Senior Engineer @ Millimeter Wave Products
Familiar
with microwave and millimeter wave amplifier designs, filters, down
converters, multipliers, passive components, waveguide theory and
antenna design and testing...
6/20/2012
After Class: The Particle Accelerators
By
1957, betatrons, cyclotrons, cosmotrons, synchrocyclotron, bevatrons,
and other forms of "trons" had the physics world all agog with anticipation
of the next big discovery. Quarks were still a decade away from
being discovered and something as exotic of the Higgs boson (aka
god particle) hadn't entered anyone's mind. The news media was agog
with reports of the world...
Arbitrage via Microwaves
If
you have wondered why the world's stock markets behave the way they
do, why the DJIA falls 150 points on one day on news of Greece leaving
the euro, then gaining 200 points the next day on news of a bailout,
then back down a day later on more news of the bailout, your confusion
is understandable. It seems that there might be nobody who actually
can predict the market's contortions and that every trade is a gamble.
You would be wrong. There is evidently a small group of elite, well-financed,
well-equipped market players who have decision advantages measured
in microseconds - just enough time to have a glimpse of the world
that almost no one else has and then execute trades based on that
privileged information. It allows them to test theories of market
reactions and make nearly instantaneous adjustments to either increase
profit on good decisions or minimize losses on bad decisions. This
is referred to as "high frequency trading." Actually, software makes
all the decisions, not actual humans, but of course that software
is created based on human knowledge. According to one
of many articles in the June 2012 edition of IEEE's Spectrum
magazine reporting on the world's money machine, a multimillion
dollar microwave link has just been built between the New York Stock
Exchange (NYSE) and the home of
Chicago-based futures traders by the company McKay Brothers
(nobody named McKay has ever worked there).
Its purpose is to exploit the lack of signal delay inherent...
QA Manager @ TRM Microwave
TRM
Microwave is looking for a Quality Assurance Manager to ensure that
the product or service we provide is fit for its purpose and meets
customer expectations. The QA manager coordinates the activities
and develops procedures and processes required to meet this aim...
Dilbert™ on Trade Shows
Being
that the world's largest RF and microwave trade show, IMS2012 (aka
MTT-S) is happening this week in Montreal, Canada, I thought this
Dilbert™ comic strip from last month would be a fitting subject
for posting on RF Cafe. Having been to a couple of the IMS shows
and talking to exhibitors, many seem to actually relate to Dilbert's
experience. The main value of having a presence there is often simply
being seen in the realm of major players, which confers a certain
level of industry prominence. So, even if spending a week at the
show does not directly result in new customers, at lease some companies
believe the cumulative effect of a persistent presence will pay
off in the long run. I tend to agree. That being said, it looks
like Melanie and I will probably not be adding to RF Cafe's cumulative
advantage this year because we likely will not be going to the IMS2012
show after all. Maybe next year.
Eavesdropping on Satellites
1963
was five years since America's first communications satellite, Echo,
was placed in orbit. Echo was a passive, spherical reflector that
merely provided a good reflective surface for bouncing radio signals
off of. By 1963, the space race was well underway and active communications
satellites were being launched at a rapid pace. Spotting and tracking
satellites has long been a popular pastime with two types of hobbyists:
amateur astronomers using telescopes and binoculars, and amateur
radio operators using antennas and receivers...
Metamaterials for RF
Metamaterials
are receiving as much attention in university research departments
these days as graphene and carbon nanotubes. What makes metamaterials
so desirable is its negative refractive index. It causes waves -
be they electromagnetic or mechanical - to bend (refract) in the
opposite direction as nearly every material found in nature. If
water droplets had a negative index of refraction, rainbows would
display color in the opposite direction with red on the bottom and
violet on the top. If a negative refractive index was the norm in
nature, our resistor color code would probably be reversed: 0=black,
1=brown, 2=violet, 3=blue=4, etc. So, why is a negative refractive
index a big deal? It allows waves (signals) to be bent (focused)
across wider bandwidths without dispersing (spreading out) the beam
spatially. It can also be used to steer waves around an object in
a manner that renders the object invisible within the bandwidth
of interest, a prime requirement for cloaking. While cloaking is
most often thought of as a military application for hiding soldiers
and equipment, it is also being studied for uses such as directing
earthquake waves and wind around buildings and bridge abutments...
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