Here is a brief synopsis on the main difference
between
glass and metal vacuum tubes - the metal case tubes generally
exhibit higher interelectrode capacitances. Unless successfully addressed, that
limits usefulness in high frequency circuits. One of the major advantageous features
of metal tubes is the built-in EMI/RFI shielding both for keeping desirable fields
inside the tubes and keeping undesirable fields from entering...
Metal-encased vacuum tubes were such a big
deal when they arrived on the scene in the mid 1930s that two successive issues
of Radio-Craft devoted the majority of print space to them. Metal tubes,
as admitted by editor and author Hugo Gernsback, did not perform as well electrically
as glass tubes yet, but that was attributed to the infancy of the technology. Overwhelming
positives, including ruggedness, lower cost of production, longevity and other aspects
would ensure that metal tubes "are here to stay." They never did even come close
to replacing glass tubes. One of the most interesting statements in the article
has nothing to do with metal tubes, but Mr. Gernsback's understanding...
Thanks to Mr.
Joe Hernandez (KN2A), the
entire set of four manuals for the
Cleveland Institute of Electronics' 515-T Slide Rule are now available
online! Joe bought the manuals and slide rule on eBay as a set, and he was kind
enough to scan the manuals and send them to me for posting on RF Cafe. Since posting
a photo of my personal 515-T slide rules and the partial user's manual I found a
few years ago, I have received many requests for the manuals. Joe is a very active
Ham radio operator and invites you to visit his page on the qrz.com/db/KN2A website.
He is a big time CW guy who likes to tinker. One item you really need to check out
is his custom-built Mouser-40
and 3 Blind Mice CW setup...
"Our increasingly connected world needs better
protection against
RF noise pollution. Radio-frequency noise pollution is everywhere.
You can't see, hear, taste, or smell this noise, of course. Nor can you summon it
and study it at your leisure, because it comes and goes along with the movements
of its sources or its victims. Start with the fact that any significant digital
appliance has a high-speed clock and a digital bus, and both leak radiation profusely.
Electric motors and generators generate RF noise with every small spark that jumps
between their...
NuWaves Engineering today introduced the
NuPower 05E05A, a compact and highly efficient solid-state power
amplifier (PA) module for S-band transmitters and data links. Providing 30 Watts
on average, and 20 Watts minimum, RF output power, the NuPower 05E05A operates from
2,000 to 2,600 MHz for CW and near-constant-envelope waveforms. The connectorized
PA module accepts a nominal 0 dBm (1 milliwatt) input
signal and provides 44 dB of RF gain while operating at 40% DC power efficiency
with a +28 VDC supply...
This is pretty cool. Just in time for Christmas
for the man-woman-boy-girl who has everything is
The Element Cube. "The Element Cube is the ultimate conversation
starter. Containing over 60 elements, in one compact cube, it's the perfect centrepiece
for your office desk or coffee table. From Aluminium to Zirconium, the cube has
it ALL." It began life as a
Kickstarter project (still is, with 11 days to go), and now has
926 backers. Its financing goal was a mere $3,804, but already has $72,105 in pledges.
The high bidder gets the world's largest alloy named after him; i.e., "Kirtonium"...
Here's another electronics-related
Hallowe'en article for you just in time for tomorrow's office
(or lab) party. I almost made an inane statement about how you can substitute a
cellphone for the radios used in these pranks, but then I remembered that a cellphone
is first and foremost a radio in and of itself. I fondly recall the old days as
a technician at Westinghouse Electric when, on the evening shift, we used to get
away with playing practical jokes on each other in the lab. Ours were low tech stuff
like connecting a high voltage supply to someone's metal toolbox or squeezing water
from a soldering iron sponge wetting bottle through a length of plastic tubing
(taped under a workbench) onto a guy's crotch while
he was working intently on something. You'd probably get fired or sued for such...
NI (formerly AWR Corporation) announces that the
University of Messina, Messina, Italy, microwave electronics research group uses
NI AWR Design Environment™
for its modeling work. A recent project has been the design of single-stage, high-power,
microwave amplifiers using complex device models for nonlinear analysis of the device
behavior as well as for amplifier optimization. "NI AWR Design Environment software
is a very valuable tool for teaching and research," said Professor Alina Caddemi.
"It offers an impressive tuning action for model performance refining that also
allows students...
Featured Book: Basic Radar Analysis
This
authoritative new resource presents fundamentals of radar analysis including the
range equation, detection theory, ambiguity functions, antennas, receivers, SP,
and chaff analysis for modern radars. This book addresses details behind the detection
probability equations and origins radar engineers commonly use to perform signal
processor analyses. This book consolidates discussions of
receiver design and analysis and treats areas of digital receivers
not commonly found in other books. Packed with details on how to perform radar range
equation and detection analyses, RCS modeling, ambiguity function generation and
antenna pattern generation. This book also includes detailed analyses of coherent
and non-coherent integration, design and analysis...
"Spectrum at 2.3 and 3.4 GHz that once was
allocated to Amateur Radio is going on the auction block in the UK. Telecommunications
regulatory agency Ofcom announced this week the steps it will take in selling off
the shared spectrum it took back after the military no longer needed it. Ofcom announced
in April 2014 that it was ending Amateur Radio access to significant portions of
the 2.3 and 3.4 GHz bands following a year-long consultation..."
"This [noise figure uncertainty]
calculator will not get the same results as earlier versions of on-line calculator
because of the different assumptions. In the most critical DUTs, the ENR uncertainty
usually dominates, and the calculators will agree for the case combination of User
Cal and 95% confidence specifications. When mismatch errors are significant, this
calculator will be more accurate, though harder to use because of all the Specification
Style and Distribution fields that can be filled in. The default settings of those
fields will be optimum for most applications...
The old
pushbutton radio tuners were an ingenuous bit of electromechanical
wizardry. For those too young to have experienced them, operation was simple - turn
the radio tuning knob to your broadcast station, pull out the lever/button, and
then push it all the way back in. Done. The next time you pushed that button, the
mechanism would slew the tuning dial to that position, taking the tuning elements
(usually just a variable capacitor) with it. For most modern electronic radios,
you program the station button by pushing and holding it for a few seconds until
a beep is heard. My father never quite got the hang of tuning the pushbutton radio
in his old Rambler (vacuum tubes) or even his 1972 Chevy pickup...
This "The
Hand of Selene" Carl and Jerry adventure appeared in the November 1960 issue
of Popular Electronics just in time for Halloween. The magazine would have arrived
in mailboxes on newsstands sometime in October. With the great popularity of zombies
and the undead these days (in which I personally have zero interest), the scheme
outlined here to make the hand of Selene (an Egyptian moon goddess) tap out answers
to a soothsayer's questions would be a great scheme to use at a Halloween party.
Read on to discover the tech savvy teenagers' clever implementation...
"The
Chief Executive Officer
is responsible for leadership and management of staff, planning and tracking financial
results and corporate compliance, maintaining effective member interface and service
levels, monitoring regulatory developments and directing advocacy and public-relations
efforts in support of Amateur Radio domestically and worldwide, and working with
the Board of Directors, Officers, and other management toward achievement of the
League's goals, strategies and plans for the betterment of Amateur Radio." This
is a dream job for a qualified
Ham who wants to help lead the organization to new highs.
For some reason the titles of this latest
batch of articles from
RF / microwave
magazines are longer than normal. I've noticed that engineering book title,
including their subtitles, seem to have been growing in length over the last couple
years as well. The November issues are out for Microwave Journal, RF &
Microwaves, Microwave Product Digest, High Frequency Electronics,
and the Test & Measurement portion of EDN...
-
The Three Pain Points of the
Mil/Aero Test Engineer
-
Control Crosstalk in RF/Microwave
Systems
-
Using Automatic Synthesis of RF,
Microwave and Analog Circuits to
Increase Design Productivity
by 10x
-
LINC2 RF and Microwave Circuit
Simulator Includes Design and
Synthesis Tools <more>
Anatech has released three new
RF / microwave duplexer
designs: a 2365-2435 MHz / 2445-2495 MHz cavity duplexer connectorized model, a
1950 MHz /2140 MHz ceramic surface model, and also a 3660.5-3685.5 MHz / 3760.5-3785.5
MHz Cavity Duplexer connectorized model. All can be ordered directly through their
AMCrf web store...
"Still have my 'RF Engineers' mug. To this
day, I still ain't got a clue what all the charts and graphs on it mean, but I sure
feel smart when I'm drinking coffee from it." -
Mr. Kim Stricker. Kim is a fellow model airplane builder and flyer
who lives and thrives in the Midwest. He is a huge aficionado of / cum lay expert
on the vintage Cox engines. He and I both owned
Jetco Shark 15 control line airplanes as kids; that is the model
in the picture. Kim is also a licensed pilot and owns a homebuilt
Pietenpol. Big motorcycles and 2nd Amendment hardware are also
among his many interests. Many of his
aviation photos have been featured in the local newspaper. Kim
has my vote for the "Man Most Living Life to the Fullest" award (if, of course,
there was one).
"A
tractor beam, reminiscent of the one used in sci-fi classic
Star Trek, has been developed that uses sound to capture and manoeuvre objects in
mid-air. The technology focuses waves of high intensity sound to grab, lift and
move small items in a similar way to a human hand, and as precisely as a pair of
tweezers. While it is a long way from being powerful enough to ensnare the kinds
of objects seen in the TV series, it..."
A couple weeks ago, Ms. Heather McGhee,
of Wurth Electronics Midcom,
wrote to me asking about getting a listing on Vendor pages for which her company
manufactured products. I obliged accordingly by adding Wurth Electronics to the
Automotive Electronics, Capacitors, EMC / EMI / RFI, Hardware, Inductors, and Substrates
/ PCBs pages. Wurth Electronics Midcom, if you are not familiar with the company,
is part of the Germany-based Würth Elektronik Group companies. Combined, they produce
thousands of circuit board-based system components for power distribution, display
and control panels, electronic controls. Power magnetics, EMC components, common
mode chokes, capacitors, transformers, RF inductors, high current PCB terminals,
printed...
"UK telecomms regulator Ofcom has
announced that it's set to start cancelling Amateur Radio licenses,
possibly numbering into the thousands, that have not been "revalidated" by the holder.
The effort appears to be, in part, an effort to clear dead wood from the agency's
databases. Amateur Radio licenses in the UK must be revalidated every 5 years, but
until Ofcom goes through the..."
I am always in awe when looking at a photograph
of one of the regions in the sky that hosts a dense cluster of galaxies - they look
like fireflies. It seems unbelievable that so many other galaxies can exist, and
that's only what we have discovered so far. This image from the
Hubble Space Telescope
(HST) is the latest in a rapidly growing collection
of such clusters. Incredibly, Earth-based telescopes are now surpassing the HST
in resolution - even with needing to look through miles of scintillation-inducing
atmosphere. Laser-created calibration stars projected into the upper atmosphere
and adaptive optics perform the magic needed to correction. The
European Extremely
Large Telescope (E-XLT), scheduled to see first
light in 2024, will utterly blow away everything that preceded it. I hope to live
that long.
Pasternack, a leading manufacturer and supplier
of RF, microwave and millimeter wave products, has released new lines of in-stock
1.85 mm, 2.4 mm and 2.92 mm
waveguide to coax adapters with operating up to 65 GHz. These
waveguide adapters are used for any number of applications such as SATCOM, wireless
communications, industrial, test and measurement and defense systems whenever there
is a requirement to transition from coax to waveguide or vice versa...
EDI CON China is pleased to announce that the China Electrotechnical
Society's (CES) Electromagnetic Technology Conference & Exhibition (EMC) will
be co-located on the 4th floor of the China National Convention Center (CNCC) taking
place 19 to 21 April, 2016 in Beijing. The combined event forms the largest microwave,
EMC/EMI and high-speed digital design conference and exhibition in Beijing. This
is a natural extension of the EDI CON China event that already covers EMC/EMI topics
but will now feature a comprehensive parallel conference and expanded exhibition.
EDI CON China has formed a pavilion specifically for EMC/EMI companies on the exhibition
floor to congregate similar companies in one area...
This 1934 edition of
Tower Radio magazine was thrown in with a batch of vintage
radio magazines I bought on eBay. Most of the content pertains to entertainers of
the day rather than with technical issues. Reportedly, it was only sold at Woolworth's
stores. Ironically, the number of households with over-the-air radio listeners today,
at least as a percentage of the population if not in absolute numbers, is probably
about the same as in 1934 when commercial radio broadcasting was just getting a
foothold. These days, a majority of people listen to radio and podcasts via cellphone
and/or Internet streaming media than from over-the-air broadcasts, even while in
their cars. Organizations like the National Association of Broadcasters are...
Optenni Ltd has released a new version of its
matching circuit optimization software
Optenni Lab™, supporting a link to Copper Mountain Technologies
(CMT) USB VNAs. The link enables users to stream the measured data directly into
Optenni Lab, where the user can specify the matching targets and synthesize matching
circuits essentially in real time. Using this connection, users can easily test
antennas and virtual matching circuit prototypes in different impedance environments...
This is the second of a two-part article titled
"How Are Short Waves Propagated?" The first part appeared in the
December 1931/January 1932 edition of Short Wave Craft.
Nancy Golden: "You don't have to be brilliant
to be a good engineer. You just need to be able to find the answers to what you
need to know for the specific task at hand. That can take the form of good Internet
research skills, and it doesn't hurt to have a decent technical library in your
office. Knowing when to call tech support or when to strike up a conversation with
a field application engineer is an important skill. To paraphrase a well-known movie
quote, always be learning, because not only is technology constantly..."
Prior to atmospheric sounding rockets and
orbiting satellites, all information gained and theories developed on the nature
of Earth's upper atmosphere and its interaction with
electromagnetic waves were purely academic, not the result of
empirical data. That is not to say the theories were wrong (although some were),
just that they were incomplete. For that matter, even today there is still much
to be learned and, according to an excellent article in the October 2015 issue of
the ARRL's QST magazine titled "Five Myths of Propagation Dispelled," there is still a lot of
misinformation being believed and promulgated about shortwaves and how they travel
in the atmosphere. This work is a great testament to the level of expertise that
exists in the realm of Amateur Radio, and the...
"Here at Keysight, we enjoy sharing insight
into the latest in electronics design, test, and measurement. Towards that end,
we thought it'd be fun to give away 1000 copies of this new book to help you stay
up to date on spectrum and network measurement fundamentals.
First 1000 Electrical Engineers to Enter. What's the
catch? If you're an engineer in the USA or Canada, simply fill in the form below.
Only one entry per person, but feel free to share with your colleagues! The first
1000 names from companies in the Electrical Engineering community will be sent a
book. Simple as that."
DO IT NOW!
"The handedness or 'chirality' of electrons
affects how current flows in graphene transistors, according to new work done by
researchers in the UK and Russia. The team's findings could help to make better
graphene-based electronic devices and could even lead to a new technology, dubbed
'chiraltronics.' Graphene is a sheet of carbon atoms just one atom
thick, arranged in a honeycomb lattice. The material is unique in that each electron
moves along the sheet relativistically, as..."
The advent of
metal-encapsulated vacuum tubes was supposed to be the death knell
for traditional glass tubes. This 1935 article from Radio-Craft spelled out the
many virtues of 'metal' tube and how in short order their superiority would obviate
the need - even desire - for "glass" tubes. I'll let you read the article for the
details, but want to make note of an evidently archaic term used that could potentially
be really popular in today's manufacturing world if duly resurrected - "quantiquality"
(aka "quanti-quality" or "quanti quality"). The connotation is a process of high
quantity in conjunction with high quality. The only references I could easily find
to quantiquality was from late-19th-century newspaper archives. If sometime within
the next few years you start seeing some...
Charles Murray, of Design News, has
come up with yet another interesting engineering trivia subject - he dug up the
names of 9 major league baseball players who have
engineering degrees. He notes that since most baseball players
are drafted out of high school, few have college degrees at all. Per Mr. Murray,
"A 2009 Wall Street Journal analysis of a thousand or so players and managers revealed
that only 26 had four-year degrees." We will, of course, expect a similar analysis
in the near future for other professional sports realms; e.g., football, hockey,
basketball, NASCAR...
"Celebrating its 10th anniversary this year,
the ARRL On-Line Auction
opened on October 22, and bidding already is hot and heavy. Participants are bidding
on the chance to own 270 items that range from Amateur Radio transceivers, test
equipment, tools, antennas, ARRL swag, memorabilia, vintage books, one-of-a-kind
finds, and — in honor of the auction's 10th anniversary — the ARRL Lab team has
contributed five "Mystery Junque Boxes." Some of the premier items..."
This week's crossword
puzzle, as with all
RF Cafe puzzles, uses only words pertaining to engineering, science,
mathematics, mechanics, chemistry, astronomy, etc. You will never find a reference
to some obscure geological feature or city, or be asked to recall the name of some
numbnut movie star or fashion designer. Enjoy!
"A Utah company
has a new nickel-carbon material that could help the Pentagon fight off some of
its most haunting threats. Your next tinfoil hat will won't be made of tinfoil.
A small company called
Conductive Composites out of Utah has developed a flexible material
- thin and tough enough for wallpaper or woven fabric - that can keep electronic
emissions in and electromagnetic pulses out. There are a few ways to snoop
on electronic..."
A
grid dip meter (aka a grid dip oscillator, dipper, or dipmeter)
has long been the instrument of choice for fine tuning LC-tuned receivers for maximum
sensitivity at a particular frequency. It is a simple device that oscillates at
a predetermined frequency and has a meter in the grid bias circuit to measure current.
When the grid dip meter tuning circuit's inductor is in close proximity to an external
inductor-capacitor tank circuit that is tuned to the "dipper's" output frequency,
the grid current exhibits a significant reduction in value - hence the name grid
dip meter. Modern versions no longer use vacuum tubes that have screen grids, but
the name persists even with the use of transistors that, for BJTs, have a base junction
and FETs, that have a gate...
"The
FCC is proposing to update its broadcast station ownership rules to allow for greater
foreign ownership, and to streamline its review and approval procedures for such
greater foreign ownership <download>. Here, in a nutshell, is what is being proposed.
It is necessary to say upfront that any discussion of the FCC's broadcast station
ownership rules quickly becomes mired in complexity and exceptions. Leaving aside
foreign ownership, even an explanation of..."
In the
year 2012 while completing his doctoral studies, Dr. Andrei Müller introduced
the world's first publically available software for portraying the classical 2-dimensional
Smith Chart in a 3-dimentional format. A brief report on the
3D Smith
Chart software was posted here on RF Cafe, and an article titled "The 3D Smith
Chart and Its Practical Applications" was published in Microwave Journal
magazine. Since that time, Dr. Müller has authored many scholarly articles
on circuit theory dealing largely with complex impedances. Recently and in collaboration
with Dr. Stepan Lucyszyn, the paper "Properties of Purely Reactive Foster and non-Foster Passive Networks"
dealt with Foster and non-Foster passive networks with 'a strongly real function
of real frequency of positive type'. It can be read in its entirety on the IET Digital
Library website for...
"A NASA-developed laser communication (lasercom) system demonstrated record-breaking data download
and upload speeds to the moon. Now, a NASA optical physicist says he can match those
speeds - plus provide never-before-achieved, highly precise distance and speed measurements
- all from the same relatively small package. Called the Space Optical Communication
and Navigation System, the breadboard technology is made up of commercially available
components simulating both ground and space..."
While
reading a great article titled "Setting up a Test Bench" in the October 2015 issue of Nuts &
Volts magazine, a reference to the
Boat Anchor Manual Archive
(BAMA) website reminded me that it has been many years since I mentioned it
here on RF Cafe. Webmaster Kenneth Grimm (K4XL) has accumulated what has to be the
world's largest collection of vintage test equipment and radio equipment manuals,
all available FREE for download. "It is made possible by the generous folks who
take the time and make the effort to scan and upload their manuals to the BAMA site."
If you have a scanned copy of a manual either not already in Mr. Grimm's collection
or a better copy of an existing one. please submit it for the benefit of others...
Ok, here's a little dose of
Ham
comedy for your Friday afternoon. It's a little bit kooky by today's standards,
but in 1940 the style of humor it fits right in. This could easily have been the
plot in an old TV show like The Honeymooners, or one of the radio situation
comedy (sitcom) programs like The Life of Riley. QRM, by the way, is Ham
lingo for man-made signal interference, as opposed to QRN, which is atmospheric
or "natural" signal interference. Enjoy...
This "Radio Service Data Sheet" covers the
International Kadette Model 66 and 666, superheterodyne receiver. Most - if
not all - electronics servicemen had subscriptions to these magazines because they
were a ready source of not just these service sheets, but because of the extensive
articles offering advice on servicing radios and televisions. In fact, many electronics
manufacturers had a policy of supplying service data only to bona fide shops. A
large list is included at the bottom of the page of similar documents from vintage
receiver schematics, troubleshooting tips, and alignment procedures. They were originally
published in magazines like Radio-Craft (this April 1936 issue), Radio
and Television News...
This Radio Service Data Sheet covers the
Ford-Philco radio model FT9, 6-tube auto-radio receiver. A large
list is included at the bottom of the page of similar documents from vintage receiver
schematics, troubleshooting tips, and alignment procedures. They were originally
published in magazines like Radio-Craft, Radio and Television News,
Radio News, etc. I scan and post them for the benefit of hobbyists who
restore and service vintage electronics...
Battery technology experienced a major technology
evolution in the late 1950s similar to the one that took place in the late 1990s.
Prior to the 50s, most common portable batteries were of the carbon-zinc type and
were not rechargeable. Nickel cadmium (NiCad) cells existed, but were not in widespread
use largely because little was known about the chemistry and how it responded to
various charge and discharge cycles. Mercury, NiCad, nickel metal hydride (NiMH),
alkaline-manganese, began gaining popularity in applications requiring longer battery
life and more consistent discharge characteristics. In the 2000s, lithium polymer
(LiPo) and lithium ion (LiIon) underwent a similar evolution. Still, all the aforementioned
battery types are in use today...
The effort to
block advertising on radio broadcasts has been going on for about
as long as advertising has been in use, as evidenced by this 1934 article in
Radio-Craft where a 'robot' advertising silencer' device is presented for removing
"superfluous advertising." Headlines from a few weeks ago announced Apple's program
for blocking ads that appear on websites, causing a big to-do about how all the
"free" content would be jeopardized since it is the advertisers who pay for the
music and other programming to be delivered to the user. Without the convenience
and economy of software to do the job in 1934, however, fairly complex discriminator
circuits were used to detect and mute the 'garrulous announcer or advertiser' between
regular programming. It's pretty funny to...
MathWorks introduced WLAN System Toolbox, providing
standard-compliant functions for the design, simulation, analysis, and testing of
wireless LAN communications systems. WLAN System Toolbox expands capabilities of
MATLAB for
wireless development by providing configurable physical layer waveforms for IEEE
802.11ac and 802.11b/a/g/n standards. The system toolbox provides reference designs
to enable exploration of baseband specifications, and demodulate and recover signals.
Users can also study the effects of RF designs and interference sources...
New options have been added for winners of
the monthly RF Cafe
Book Drawing. Amongst them is
Spectral-Spatial Classification of Hyperspectral Remote Sensing Images,
by Jon Atli Benediktsson (graciously provided by
Artech House).
"This comprehensive new resource presents recent developments in the classification
of hyperspectral images using both spectral and spatial information, including advanced
statistical approaches and methods. The inclusion of spatial information to traditional
approaches for hyperspectral classification has...
If you watched
Back to the Future Part II, released to theaters in 1989,
you might recall that October 21, 2015 was the date Marty McFly dialed into Doc
Brown's DeLorean time machine in order to fix the future "him" and, more importantly,
his kids. BBC News published an article titled "Back to the Future
II: What Did It Get Right and Wrong?" Among them are silent (electric) cars,
converting garbage into energy, and large screen home televisions.
Both
Lexus and
Hendo have
recently made news with its prototype "hover board." Oh, another thing the film
got right was that in 2015, when you get older, you look older - heavy sigh.
Radio Frequency Systems (RFS) is a global wireless and broadcast
infrastructure specialist which designs and manufactures cable, antenna and tower
systems, as well as active and passive RF conditioning modules, providing total-package
solutions for outdoor and indoor wireless infrastructure. At the 5th Annual Canadian
Wireless Trade Show, RFS will showcase a variety of its end-to-end infrastructure
solutions, including: Low-inductance HYBRIFLEX cables that feature special wiring
to reduce overall cable inductance...
NI (formerly AWR Corporation) announces that it
is sponsoring "Breakthroughs in Phased Arrays and Radar" as part of Microwave
Journal's RF/microwave technical education webinar series. Moderated by Dr. Eli
Brookner, IEEE Life Fellow and former radar expert at Raytheon, this webinar examines
the significant improvements in radar capabilities made possible by the advent of
the active phased array antenna...
This edition of National Radio News
announces the FCC's approval of the first 15
FM broadcast licenses for stations spread across the country.
It is also the first issue following America's entrance into WWII and includes a
question from a Ham regarding whether simply listening to radio reports was allowed.
As you might know, the FCC prohibited amateur radio operators from transmitting
for any reason during both World War I and World War II. The reasons given
were clearing the airwaves to make monitoring easier, to prevent intentionally encoded
messages from being sent, and to keep homeland status information from being broadcast.
Homeland status could be ascertained by assimilating reports of who was being drafted
and entering service and...
"Sometime in the past 30 years, electronics
got so complex and automated that product manufacturers took control away from us,
and radio stations became a number. But a radio station is not a number. It is a
place, and it has 'width.' How wide it is depends on how far away you are from the
station, how powerful it is, and how your radio was designed." -
Heathkit Explorer Jr.™ webpage note.
Game playing with a remote opponent is routine
these days thanks to the Internet, but a couple decades ago it was not quite so
easy. A checkers or chess match via telephone, snail mail, or even fax
machine were the venues available to the common man, but Hams had another means
- radio! Using either Morse code or voice and a playing board set up like the one
shown in this article, two players could easily match wits anywhere in the world
where signals could be exchanged. Evidently the participants could get so wrapped
up in the game that they risked forgetting to broadcast their call signs at the
legally required interval (every 10 minutes), so author Utterback provides a friendly...
Advanced Test Equipment Corporation is a world-wide
Hi-Tech equipment rental company located in Sorrento Valley. We are seeking a technical
person or engineer to write technical articles and web content for our website on
Test & Measurement equipment. A background in engineering or test and measurement
equipment is a plus! Responsible for researching, writing and editing, summarizing
data from data sheets to transform intricate technical content into user friendly
specs. This position requires in-depth knowledge of test & measurement equipment
as well...
"In the 21st century,
photonic devices, which use light to transport large amounts of
information quickly, will enhance or even replace the electronic devices that are
ubiquitous in our lives today. But there's a step needed before optical connections
can be integrated into telecommunications systems and computers: researchers need
to make it easier to manipulate light at the nanoscale. Researchers at the Harvard
John A. Paulson School of Engineering and Applied Sciences have done just that,
designing the first on-chip metamaterial with a refractive index of zero, meaning..."
Reactel has become one of the industry leaders
in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. We have
established a full line of filters of all types. Latest CAD/CAM methods and equipment
used in design and manufacturing. Many filter designs are available in either tubular,
rectangular, or waveguide packages, connectorized or surface mount, and standard
or high power versions. Frequencies up to 50 GHz, depending on filter type.
"As part of an ongoing research and design
project 'to dramatically improve the usability and functionality' of its website,
the FCC has debuted a new prototype
website and wants to know users think about it. The FCC's 2011 website re-design
was not well received, and the Commission has continued to maintain its previous,
much-older website design in tandem with the newer one. 'You spoke, we listened,'
FCC Chief Information Officer David Bray said in an..."
During and immediately following World War II,
the 'Monitoring Service' of the British Broadcasting Corporation (BBC) relentlessly
listened to radio broadcasts from all over the world in order to be able to break
headline news and, if appropriate, pass strategic military information on to Allied
command centers (who were simultaneously doing their own monitoring). This article
tells of some of the more significant messages intercepted and how the facility
was a highly guarded secret in order to prevent sabotage and infiltration. At the
height of activity, 32 languages were being transcribed into English daily, consisting
of more than...
P1dB, an RF and Microwave component supplier,
announces in-stock availability of a series of broadband RF couplers that operate
from 0.5 to 18 GHz. The SMA Directional couplers, series number
P1CP-SAF-R518G30W, come in 10 dB, 20 dB and 30 dB
values as standard items, but other values are available upon request. The Directional
couplers are designed to handle 30 watts of input power...
I
signed up as a
"Heath Insider" about a year ago when news first broke about Heathkit's
intention to finally, after a couple decade hiatus, begin producing built-it-yourself
electronics kits again. The
Explorer Jr.™ is a basic capacitor-tuned AM radio kit
that comes complete with everything needed to build it. Why not a digitally tuned
synthesizer with an LCD display? Company president Andy Cromarty promises many more
kits to follow, with all being in the classic Heathkit tradition of high quality
parts and well-written, illustrated, step-by-step instructions. It will be a continuation
of their "You Can Build It. We won't let you fail." motto. An e-mail arrived a few
days ago stating the following: "Here's a quick summary of what we've quietly been
doing at Heathkit during the past year: We assembled a terrific team of very talented...
OK, I admit that this week's
crossword puzzle is a little self-serving and self-promoting,
but what the hey. All of the clues with an asterisk (*) after them are categories
in the table of contents at the tops of RF Cafe website pages, so that should help
a bit. To make it even easier, they are all on the "Main" TOC menu. As always, this
crossword contains no names of politicians, mountain ranges, exotic foods or plants,
movie stars, or anything of the sort unless it/he/she is related to this puzzle's
technology theme (e.g.,
Hedy Lamarr
or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
MECA's new compact 50 watt and 100 watt
Low PIM Attenuators (-160 to -165 dBc typical) feature industry
leading thermally stabilized low PIM distortion performance (low thermal noise).
In addition all of the terminations cover 0.698 – 2.700 GHz frequency bands. Also
available in: Type N, 4.1/9.5, 4.3/10.0, and 7/16 DIN models both within connector
series and mixed series configurations...
Designing resistive
impedance-matched signal splitting networks is nowadays mostly
done with the assistance of computer software. In fact, odds are pretty high that
the designer either has no idea what the formulas behind the "magic" are, or at
least it has been a very long time since working them with pencil and paper. There's
no shame in that, though, just as there is no reason to expect someone using a cellphone
must know the intricacies of the internal circuits or the network to which it is
connected. We've moved past that. For those of us who still appreciate a refresher
on the behind-the-scenes calculations being performed at lightning speed...
Planar Monolithics Industries (PMI) has just
released PMI-What-Weve-Been-Doing-10-15-2015.htm" >8 new devices for the RF and
microwave market. Among the list is an 18-40 GHz successive approximation log video
amp, an 8-18 GHz high speed 5-bit frequency translator, a 30 MHz to 26.5 GHz LNA,
and a 10 MHz - 6 GHz portable amplifier. PMI has one of the industry's largest selections
of RF and microwave products spanning from DC...
A 1-year subscription to the very popular
Explore RF online
course, created and hosted by Dr. Francesco Fornetti, will be available again
as an option for the December 2015
RF Cafe Book Drawing.
Dr. Fornetti graciously provided two subscriptions last year shortly after
first publishing his Conquer
RF Frequency book that accompanies the course. Both were selected by winners
immediately - passing up an otherwise great array of other high quality, recently
published engineering books.
Keysight Technologies, via the
IEEE ComSoc folks, has provided
a free online tutorial titled "Error Vector Magnitude Measurements Fit for 5G." Summary:
Error vector magnitude, EVM, measurements have been the mainstay of modulation performance
analysis for more than twenty years. Each new technology has defined a specific
measurement to suit the characteristics of the physical layer signal. The interest
in signals for 5G that are much wider bandwidth, operating at much higher frequencies
means it's time to draw a comparison between the different waveforms...
World War II was the "necessity" that
elicited the "mother of invention" activity responsible for many huge leaps in technology
- not the least of which was electronic verbal and non-verbal communications. Along
with radio and radar, Loran had become a major means of ocean and air navigation.
A fair description of the operational details, including timing diagrams, is included
in the text. Loran-A, the original system as it came to be known, was fully decommissioned
in 1980, thereafter supplanted by
Loran-C. With the advent of GPS, Galileo, and Glonass navigation
systems and their low and their low equipment and installation costs...
"While the US military continues to develop
new and awesome ways of blowing aerial drones to smithereens, not many of these
systems can easily be adapted to use in the civilian realm. That's why Battelle
has developed the
DroneDefender, a shoulder-mounted rifle that knocks UAVs offline
with a barrage of radio waves. It easily and reliably neutralizes the threat." The
weapon weighs roughly 10 pounds and can target drones up to 400 meters away..."
