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5 of the May 2022 homepage archives. Friday the 13th
 Add-on devices like this "TV-IF
Signal Booster" began appearing in all sorts of magazines back in the early
1950s as television sets became more and more of a household fixture, and people
were beginning to assume the now well-establish couch potato domestic class. According
to this advertisement by Grayburne Corporation, "experience proves a 20% average
boost in overall signal is all that's needed to give satisfactory reception." Since
their signal booster plugs into the IF path, it is probably safe to assume the gain
refers to voltage and not power. A 20% gain in voltage is 10 * log (1.2) = 0.79 dB,
which is not much. Most likely the vast majority of TV installations would benefit
much more from fine tuning of the antenna and transmission cable system, but to
be fair, this devices targets indoor installations where the antenna is rabbit ears
that came installed on the set. In that case, relocating the television to another
place in the room and fiddling with the rabbit ears would also likely result in
as much or more of an improvement as the booster...
 "Hong Kong University of Science and Technology
(HKUST) reports on a
gallium nitride (GaN) non-volatile memory (NVM) with good speed, retention and
endurance at the same time. In silicon-based NVMs there tends to be a trade-off
in these characteristics, creating a manufacturing 'trilemma' due to the use of
Fowler-Nordheim tunneling across a tunnel oxide (TO) to change the memory state.
The researchers comment: 'This work shows that the mainstream GaN-on-Si platform
can also accommodate high-performance non-volatile memory devices in addition to
the power and radio frequency (RF) devices, to enable highly intelligent electronic
systems.' The device integrated a p-channel field-effect transistor (p-FET) with
p-i-n heterojunction diode. The p-FET consisted of aluminium oxide (Al2O3) gate
insulator on p-GaN..."
 This Radio Service Data Sheet for the
Kennedy Superheterodyne Short-Wave Converter (Model 54 "Globe Trotter") is an
example of the dozens of similar schematic and alignment instruction sheets that
have been posted on RF Cafe over the years. It appeared in a 1932 issue of Radio-Craft.
Obtaining technical information on most things, even readily available items, prior
to the Internet era was often very difficult - if not impossible. Service centers
had what was need provided by manufacturers and distributors, but if you wanted
to find a part number or service data on a refrigerator, radio, lawn mower, garage
door opener, etc., and did not have the original paperwork, you were usually out
of luck. Nowadays a Web search will quite often get you what you need thanks to
people (like me) who go to the trouble of making the information available. The
stuff doesn't just magically appear or get posted by benevolent governmental entities...
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
Raytheon now has an opportunity for an experienced
Senior Electrical Engineer: TWT & HPA Design who is seeking to utilize their
strong academic background and experience in High Power/High Voltage Transmitters.
This position requires an experienced senior technical and business leader with
a proven track record of invention, capture, and successful execution in High Power
Microwave (HPM) and Pulsed Power technologies. Responsibilities include design and
hands-on testing of high voltage/high power RF components plus providing technical
support to production activities across multiple programs. Team leadership skills
including cost and schedule management plus proposal writing and presentation experience
are desired...
 "It is anybody's guess as to what modulation
system the amateur of 1975 will be using." That forward-looking line appeared in
this 1947 QST magazine infomercial by the
National Company. The writers probably had no real idea how different electronics
would be 25 years in the future, especially since John Bardeen et al would not invent
the transistor until two more months (December 1947) after the publication of this
issue. In their traditional style, this full-page advertisement was heavy on text
and light on images. The company invested in customer education with the hope being
a well-informed and appreciative hobbyist would reward them with patronage...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic
drawings! Every object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Symbols are provided
for equipment racks and test equipment, system block diagrams, conceptual drawings,
and schematics. Unlike previous versions, these are NOT Stencils, but instead are
all contained on tabbed pages within a single Visio document. That puts everything
in front of you in its full glory. Just copy and paste what you need on your drawing.
The file format is XML so everything plays nicely with Visio 2013 and later...
 Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
RF today.
Thursday the 12th
 There is a physical limit to how small of
a distance may separate two distinct objects (line, dots, etc.), generally agreed
to be about half a wavelength of the color being observed, and be seen with perfect
human eye. Applying that rule of thumb to blue light with a wavelength of approximately
4000 Å (400 nm) yields a distance of 200 nm. Accordingly, there is
no amount of magnification possible which will allow a healthy human eye to resolve
objects closer together than that. Even with perfect optics, magnifications of greater
than about 1500x are not able to render greater detail. To resolve smaller distance
requires shorter wavelengths, but we cannot see them directly and need a device
to transform the detected image into a visible image. That is what an
electron microscope does to enable molecule sized particle to be "seen." The
SARS-CoV-2 particle has been measured by electron microscopy and found to range
between 50 to 140 nm, so it cannot be viewed directly with an optical microscope.
Cigarette smoke is about 400 nm in diameter...
 "This paper describes the fabrication of
digital logic circuits comprising resistors and diodes made from
protein complexes
and wired together using printed liquid metal electrodes. These resistors and diodes
exhibit temperature-independent charge-transport over a distance of approximately
10 nm and require no encapsulation or special handling. The function of the protein
complexes is determined entirely by self-assembly. When induced to self-assembly
into anisotropic monolayers, the collective action of the aligned dipole moments
increases the electrical conductivity of the ensemble in one direction and decreases
it in the other. When induced to self-assemble into isotropic monolayers, the dipole
moments are randomized and the electrical conductivity is approximately equal in
both directions. We demonstrate the robustness and utility of these all-protein
logic circuits by constructing pulse modulators based on AND and OR logic gates
that function nearly identically to simulated circuits. These results show that
digital circuits with useful functionality can be derived from readily obtainable
biomolecules using simple, straightforward fabrication techniques that exploit molecular..."
 Astronomers consider all elements heavier
than helium to be metals. That definition obviously does not jive with the standard
chemical definition of a metal as an element that readily conducts electricity,
but a concept called "metallicity"
argues that from a star (and therefore the universe) formation perspective, extremely
high temperatures and pressures in first generation stars (like our sun) preclude
the identification of distinct elements other than hydrogen and helium. Heavier
elements, such as lithium (#3 on the periodic chart and a major component in LiIon
batteries, is classified as a metal in chemistry) are overwhelmingly created after
a massive enough hydrogen star collapses and begins fusing H and He into heavier
elements. The relative abundance of hydrogen in the universe is deemed to be about
92%, and helium is 7.1%, so together they comprise about 99% of all elements. Universally,
oxygen is at 0.1%, carbon is 0.06%, nitrogen is 0.015%, silicon is 0.006%, and iron
is 0.004%. By comparison, the Earth's elemental composition is 48.8% oxygen, 14.3%
iron, 13.8% silicon, 0.2% hydrogen...
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
Raytheon Missiles and Defense is seeking an engineering professional to work with
a variety of programs as a contributor to detailed design, simulation, product development,
and initial product testing. The RF Products Department is currently searching for
Electrical Engineers who have experience designing RF and Microwave hardware &
CCA design, including transmitters, receivers, and exciters. This role includes
design and test activities that span preliminary design to integration. Products
we develop support radar and datalink applications on a variety of tactical missile
programs. Critical to this role will be designing for challenging mechanical constraints
and extreme environments...
 News reports are full of features about
the wave of radio controlled (R/C) "drones" terrorizing citizens with their often
inexperienced pilots navigating their camera-laden craft to peer into bedroom windows,
obtain "birds-eye" views of sporting events, and to be a general pain in the posterior
to people trying to enjoy their right to privacy and safety (except, of course,
unless it is the Government choosing to violate them). Incredible advances in radio,
navigation, and sensor systems has facilitated a wide variety of very affordable
multirotor (the correct term, not "drone") aircraft that can literally fly themselves.
For under $500 you can buy a
GPS-guided multirotor that can be programmed to fly to one or more waypoints
and return to the launch location, with range and flight duration limited only by
battery capacity. Gimbaled, remotely steerable cameras can snap photos or record
video and either store it onboard for later retrieval or wirelessly transmit the
images back to the operator. Platform stabilization is provided by ultra-miniature,
ultra-lightweight orientation and rate gyros...
 This quiz is based on the information presented
in Battlespace Technologies: Network-Enabled
Information Dominance, by Richard S. Deakin. Published by Artech House. Note:
Some of these books are available as prizes in the monthly RF Cafe Giveaway. This
book has some of the best photos of modern war-fighting technology that I have seen.
"The era of mechanized warfare is rapidly giving way to the battle for information
superiority enabled by electronic technologies that provide data for detailed analysis
of enemy forces and capabilities. this book discusses how to use sensor technologies,
including radar and electronic warfare systems, to disseminate information to key
decision makers in timely and relevant manner..."
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies for
amplitude and phased matched VNA applications as well as standard & precision
RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the
iBwave component library. They also provide custom coax solutions for applications
where some standard just won't do. A partnership with Newark assures fast, reliable
access. Please visit ConductRF today to see how they can help your project!
Wednesday the 11th
 When beginning to read this 1954 Radio-Electronics
magazine article, I almost missed the uniqueness of the author's name:
Henry Farad. Usually something like that appears in an April edition, but this
being March, I figured it was just a clever device used by whomever really wrote
the story. For anyone trying to enter the field of electronics repair in that era,
reading this piece must have been discouraging, and Mr. Farad makes that clear
up front by stating, "He is up against a problem as old as civilization - he hasn't
been able to find a job because he has no experience; he can't get any experience
because he can't find a job!" Profit margins were very low in repair work due to
the usually undeserved reputation of service shops as being rip-off joints. Taking
on an apprentice was a luxury few could afford since the payoff would take so long.
Radio, TV, record players, etc., were not generally serviceable by laymen (except
for swapping out vacuum tubes), and the throw-away mindset was not yet possible
because of how relatively expensive those sets were. Accordingly, you might think
knowledgeable servicemen...
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
Job Summary: Raytheon Missiles & Defense miniaturized guided weapons – rockets,
artillery, GPS-guided mortars, radar-seeking and anti-armor weapons. (Raytheon image)
"High-tech guidance systems are fitting into increasingly smaller weapons as engineers
work to bring them the same pinpoint accuracy once found only in mammoth missiles
and hulking bombs." The
Guidance Electronics Team provides Electrical Systems Engineering to develop
Guidance Electronics solutions for products across the Raytheon Missiles and Defense
(RMD) portfolio. Our team develops missile Guidance Electronics Hardware. Our core
electrical engineering responsibilities include architecture, analysis, requirements,
integration, and test. Our core electrical engineering technologies include RF/RADAR,
Navigation/IMU/GPS, Digital, and Power...
 If you have ever placed a
fixed resistor in parallel with a potentiometer to reduce the total resistance,
then you are familiar with how you also convert a linear relationship of the wiper
movement with resistance to one that is nonlinear. That is because the equation
changes from Rtotal = Rx:potentiometer (where x is the potentiometer
position) to Rtotal = (Rx:potentiometer * Rparallel) / (Rx:potentiometer +
Rparallel). The graph of it looks like one of the curves in this chart.
Since the total parallel resistance is always smaller than the lowest value of the
two resistances, the greater the ratio of the two is, the more dominant the smaller
resistance value becomes. That means as the potentiometer wiper approaches the minimum
resistance end of its travel, the parallel resistor attached across it has virtually
no effect. Since parallel-connected inductors and series-connected capacitors scale
in the same manner as parallel-connected resistors, this chart is useful for those
circuits as well. Series-connected resistors and inductors, and parallel-connected
capacitors are simply the sums of their individual values...
 Triad RF Systems has secured a seven-figure
design and production order from a prominent South Asian aerospace and defense company
for the THPR1039, Triad's new, DTC-based, high power radio system designed for use
in Group 2 UAS. The
THPR1039 is a 10 W (5 W per channel), L-Band, dual MIMO radio that
is used for long distance UAS Video and C2 links, which achieves RF link ranges
in excess of 50km when used in both the ground and air radio segments. This unit
is an expansion of Triads High Power Radio System (THPR) product line. It combines
a DTC Solo8 MIMO radio, high power amplification, and custom filtering into a single,
easy to integrate package. Group 2 UAS require the lightest payloads possible to
maximize their flight endurance and mission duration. For this aircraft, Triad was
given a directive to minimize the weight of the radio system. Triad's engineering
met this challenge by designing the THPR1039's housing from magnesium alloy, instead
of the aluminum alloys traditionally used for housing RF systems...
 Benjamin Franklin is famous for his
kite-flying experiment whereby he "discovered" not electricity (as many people
believe), but that lightning is a form of electricity (most people thought it was
a jet of gas). A lesser known fact about Mr. Franklin is that he invented the
lightning rod after realizing the electrical nature of lightning. His understanding
of electric fields facilitated an implementation whereby hefty iron cabling interconnected
a tall, pointed rod installed at the tallest point on a building and a spike driven
into the ground. Lightning typically strikes the object that is the shortest distance
(in terms of electrical field strength) from it because the discharge can begin
at the lowest voltage. The presence of the grounded lightning rod above the highest
point on a structure effectively brings that point all the way down to ground level,
rendering it no longer as electrically tall, thereby reducing its likelihood of
being struck by lightning. Contrary to common belief, the purpose of a lightning
rod is NOT to attract lightning and provide a discharge path for the bolt. Benjamin
(he insists I call him "Ben") was a hero in Philadelphia where his invention almost
totally stopped the rash of fires that occurred all around the city whenever a major
lightning storm occurred...
RF Cascade Workbook is the next phase in the evolution of
RF Cafe's long-running series, RF Cascade Workbook. Chances are you have
never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system
cascade parameter and frequency planner that includes filters and mixers for a mere
$45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch
and the format is entirely customizable. It is significantly easier and faster than
using a multi-thousand dollar simulator when a high level system analysis is all
that is needed. An intro video takes you through the main features...
 Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Vector
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments.
Tuesday the 10th
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
The
Production Support Engineer is responsible for Circuit Card Assemblies (CCAs)
and other electrical subsystems hardware. We are seeking candidates with the skills
and passion to engineer complex systems, subsystems, circuit card assemblies and
components. A successful candidate is one who can participate in a multi-disciplined
team and properly apply engineering tools and processes. A candidate willing to
collaborate and coordinate with Operations, Supply Chain, Quality, and other Engineering
disciplines to resolve issues that may arise during production, testing, and integration.
Qualified candidates must have experience with digital, analog and/or RF testing
and experience debugging complex circuit card assemblies or electro-mechanical systems.
Knowledge of RF / microwave devices preferred...
 In the opening scene of "Gladiators," Quintus
remarks to Maximus (Russell Crowe), "A people should know when they've been conquered."
Such truth is applicable to society today regarding ubiquitous surveillance. Less
than decades ago the media was filled with stories of outrage over the discovery
of some new form of monitoring and reporting system having been installed on highways,
in shopping malls, along sidewalks, even bathrooms. Since the 9/11 terrorist attacks,
anything goes with government snooping. Count the numbers of freedoms you have lost
and the inconveniences suffered because of those 19 men with no identifiable common
cause (wouldn't want to "profile"), 15 of which came from Saudi Arabia, and how
they changed our lives forever. But, I digress. This story from 1956 shows how long
stealth installation of
radar speed traps have been in use. I was very surprised to see the detector
disguised as a street lamp at such an early date...
 "Joel Berkson, a third-year doctoral student
at the University of Arizona James C. Wyant College of Optical Sciences and Steward
Observatory, has developed a new way for precisely
measuring the surfaces of radio antennas, which are used to collect and focus
radio waves for astronomy and satellite communications. These dish-shaped antennas,
like the ones depicted in the 1997 movie 'Contact' starring Jodie Foster, must be
manufactured with an extremely high level of accuracy to work well. To ensure their
accuracy, engineers measure the antenna surfaces using metrology, a technique that
applies the science of measurement to manufacturing, instrumentation and calibration
processes. 'People always want to make larger, more accurate antennas for radio
telescopes, and more of them..."
 This
RF & Analog Company Name Change History Quiz challenges your knowledge of
the history of familiar electronics products companies' name changes (aka etymology).
Many of you have lived through the plethora of acquisitions, mergers, and name changes
represented here. There might be more than one correct answer. You might need a
motion sickness pill when navigating all the changes. Wikipedia is used as the reference
because I know the historical information presented there is accurate (enough)...
 TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between -100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
 Trameto, the innovator of smarter
energy harvesting power management ICs (EH PMIC), announced today it has successfully
closed the second round of seed funding with investment partners the Development
Bank of Wales and u-blox AG (SIX:UBXN), a leading global provider of positioning
and wireless communication technologies and services. Development Bank of Wales
is an existing equity investor and board observer, and u-blox AG will also join
the board as an observer. Commenting on the investment, Huw Davies, CEO and co-founder,
says, "This funding round enables us to embark on the next part of our journey to
engage more widely with the market to complete and promote our OptiJoule® energy
harvesting PMIC solutions. Meeting the demand to remove or reduce the reliance on
batteries used in wireless IoT devices is one of the initial application markets
we are addressing. OptiJoule's harvester-agnostic and autonomous approach..."
 Galvanometers are the basis for most analog
type meter movements - remember those things? They work by having the current flowing
through a fine wire coil armature generate a magnetic field that displaces an attached
needle. Most galvanometers respond nearly linearly to applied current, and therefore
are used in voltmeters and ammeters with simple resistor series and parallel configurations.
The
current-squared galvanometer on the other hand, as reported in this 1931 issue
of QST magazine, responds roughly linearly to power values. It can therefore
be used in a transmitter output monitoring circuit, for instance, or within amplifier
interstage coupling circuits to indicate peak coupling values while tuning. Yes,
a linear ammeter could be used, but its needle deflection in terms of power would
be nonlinear and could make obtaining fine adjustments readings difficult to discern...
 New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 12,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. I also re-broadcast homepage
items on LinkedIn. If you need your company news to be seen, RF Cafe is the
place to be.
 Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners
(hence 'Triad') with over 40 years of accumulated
knowledge of what is required to design, manufacture, market, sell and service RF/Microwave
amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating
amplifiers are available, in formats including tower mount, benchtop, rack mount,
and chassis mount. "We view Triad more as a technology partner than a vendor for
our line-of-sight communications product line." Please check to see how they can
help your project.
Monday the 9th
 John Potter Shields was somewhat of a prolific
author of technical books, primarily on the subjects of electronics and amateur
astronomy - both of which are interests of mine. This "New
Sound Recoding System" article from a 1952 issue of Radio-Electronics
magazine reported on a system he devised for writing audio to a photographic plate
in a manner similar to a record engraving on a platter. He places an unexposed film
plate in front of a cathode ray tube (CRT) and modulates the beam with audio, which
is superimposed on a deflection plate signal that moves the beam (cathode ray) in
a spiral of fine spacing from the outside edge of the CRT in toward the center -
just like a record (both shellac* - the kind Moe would break over Curly's head -
and vinyl). There is an amazing c1942 RCA video showing how shellac records were
made. Note the nearly total absence of safety devices on machinery or on operators.
I also notice an absence of visual inspection for surface flaws or contamination
during the master production process...
 "When you're baking a cake, it's hard to
know when the inside is in the state you want it to be. The same is true - with
much higher stakes - for microelectronic chips: How can engineers confirm that what's
inside has truly met the intent of the designers? How can a semiconductor design
company tell whether its intellectual property was stolen? Much more worrisome,
how can anyone be sure a kill switch or some other hardware trojan hasn't been secretly
inserted? Today, that probing is done by grinding away each of the chip's many layers
and inspecting them using an electron microscope. It's slow going and, of course,
destructive, making this approach hardly satisfactory for anybody ... [A]fter pondering
this problem, we considered using
X-rays to nondestructively image chips. You'd need to go beyond the resolution
used in medical X-ray scanners. But it was clear to us that the needed resolution
was possible. At that moment, what we've been calling the 'chip scan' project was
born..."
 These six
schematics and parts lists were published in a 1946 issue of Radio News
magazine. Included models are the Hoffman Model A300, the Emerson Model 505, the
Olympic Models 6-501, 6-502, 6-503, the Radiola Models 61-5, 61-10, the Farnsworth
Models ET-060, ET-061, ET-063, and the General Electric Model 321. All are tabletop
models. Many, if not all, of these radios can be found on eBay eventually - maybe
even right now. In fact, all of the thumbnail images shown below were just pulled
from eBay listings...
 Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. Three new
filter models have been introduced - a 912.5 MHz GSM cavity bandpass filter
with N-type connectors, a 906-924 MHz surface mount ceramic duplexer, and a
120-1000 MHz highpass filter with SMA connectors. Custom RF power directional
coupler designs can be designed and produced when a standard cannot be found, or
the requirements are such that a custom approach is necessary...
 National Company, headquartered in Malden,
Massachusetts, was a manufacturer of radio receivers for military and amateur use
in the mid part of last century. They ran many full-page advertisements that were
actually infomercials in that much more of the content presented generally useful
technical information than pitched a product. This particular installment, which
appeared in a 1951 issue of QST magazine, describes how extensive experimentation
and testing on their HRO-50 receiver by a Ham radio guy led to a circuit change
in future production models. It involved adding a tuning stage to the band select
filter. An equivalent scenario today would probably involve an algorithm change
to the SDR (software-defined radio) software...
 RF Cafe's raison d'être is and
always has been to provide useful, quality content for engineers, technicians,
engineering managers, students, and hobbyists. Part of that mission is offering
to post applicable job openings. HR department employees and/or managers of
hiring companies are welcome to submit opportunities for posting at no charge
(of course a gratuity will be graciously accepted). 3rd party recruiters and
temp agencies are not included so as to assure a high quality of listings.
Please read through the easy procedure to benefit from RF Cafe's high quality
visitors ...
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Sunday the 8th
 This May 8th custom made
crossword puzzle has an Amateur Radio (aka Ham Radio) theme, compliments of
RF Cafe. Clues specifically related to the Ham Radio theme are marked with
an asterisk (*). All RF Cafe crossword puzzles are custom made by me, Kirt
Blattenberger, and have only words and clues related to RF, microwave, and mm-wave
engineering, optics, mathematics, chemistry, physics, and other technical subjects.
As always, this crossword puzzle 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., Reginald Denny or the Tunguska
event in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
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.
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