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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.
 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?
 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...
 Wireless Site Survey Using a Handheld Spectrum
Analyzer, by Agilent Technologies, Wednesday, July 11, 1:00 pm EDT
 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...
 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 ;-)
 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...
 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...
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)...
 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.
 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.
"Successful technology is invisible. It gets out of the way and lets us live
our lives." -
Amber Case of Geoloqi (Jul/Aug 2012
Inc.)
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..."
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..."
 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...
 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...
 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...
 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...
 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...
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..."
 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...
 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...
  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)...
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)...
 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...
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.
 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...
 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...
-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
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
 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...
 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...
 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.
 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...
 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.
 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...
 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...
 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...
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" 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 (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.
 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...
-Archive-
We prefer not to call people 'seats.'" --
Jason Fried, re enterprise software applications
Load-Pull Techniques with Applications to Power Amplifier Design,
by Fadhel Ghannouchi, Mohammad Hashmi
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.
Familiar with microwave and millimeter wave amplifier
designs, filters, down converters, multipliers, passive components, waveguide theory
and antenna design and testing...
6/20/2012
 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...
 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...
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...
 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.
 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 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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