See Page 1 |
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archives. Thursday the 21st
 Who hasn't, at one time or another, knowingly
or not, quoted or paraphrased one of
Yogi Berra's famous utterances? "It ain't over 'til it's over ," "Ninety percent
of the game is half mental ," "When you come to a fork in the road, take it," and
"It's déjà vu all over again ," are legend. They are affectionately known as "Yogi-isms."
The New York Yankees catcher, manager, and coach, Lawrence Peter "Yogi" Berra, was
born on May 12, 1925. Hanna-Barbera's famous pic-a-nic [sic] basket snatching Yogi
Bear first appeared in 1958 (eight years after this article was written). According
to legend, the ballplayer sued the bruin (not the Boston hockey team) for allegedly
misappropriation of his name. The similarity of not just the name, but the Barbera
part of the creator's name seemed too coincidental to be happenstance. Hanna-Barbera
claimed Yogi Bear was patterned after Art Carney's character, Ed Norton, on The
Honeymooners TV show. Yogi's life story is typical of a sports-loving guy of his
era; would that it had been my era, too...
 This article reporting ongoing research
for auto anti-collision systems and backup warning systems appeared in a 1972 issue
of Popular Electronics magazine has only come to practical fruition within
the last decade and a half. High-end cars were offering such equipment options in
the early 2000s, but it has only been commonplace since around 2010. 1972 components
were still pretty large and power hungry, and digital processing capacity and speed
was significantly less advanced as well. Bendix, one of the early developers of
anti-collision systems, estimated that the option on a new car might add about $200
to the price, which was a really ambitious estimate, even considering that is the
equivalent of $1,4511 in 2023 money per BLS Inflation Calculator. The total add-on
cost of both anti-collision and backup warning systems on today's automobiles probably
doesn't even hit that figure, and the performance is orders of magnitude better.
The price and sizes of transmitter signal generators and receiver sensors (antennas)
are amazingly low, as are all the other system components...
 The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has an extensive
coaxial cable parameter calculator. Since 2002, the original Calculator Workbook
has been available as a free download. Continuing the tradition, RF Cafe
Espresso Engineering Workbook™ is also
provided at no cost, compliments of my generous sponsors.
The original calculators are included, but with a vastly expanded and improved user
interface. Error-trapped user input cells help prevent entry of invalid values.
An extensive use of Visual Basic for Applications (VBA) functions now do most of
the heavy lifting with calculations, and facilitates a wide user-selectable choice
of units for voltage, frequency, speed, temperature, power, wavelength, weight,
etc. In fact, a full page of units conversion calculators is included. A particularly
handy feature is the ability to specify the the number of significant digits to
display. Drop-down menus are provided for convenience. Now that a more expandable
basis has been created, I plan to add new calculators on a regular basis...
 "The U.S. Air Force has received its first
EC-37B Compass Call electronic warfare aircraft from contractors BAE Systems
and L3Harris Technolgies, industry officials announced Tuesday. BAE Systems said
in a release that the Air Force will next start combined developmental and operational
testing for this Compass Call, the first of 10 aircraft planned for the Air Force.
The new EC-37B fleet will replace Air Combat Command's decades-old EC-130 aircraft,
which the service is now retiring. BAE builds the electronic attack components of
the new Compass Call in Hudson, New Hampshire, and L3Harris integrates that mission-specific
hardware into a Gulfstream G550 business jet at its facility in Waco, Texas. The
Compass Call will conduct a variety of electronic warfare missions to jam enemy
signals, including communications, radar and navigation systems. BAE said this will
include suppressing enemy air defenses by blocking their ability to transmit..."
 While not a second-hand store junkie, I
do like to occasionally make the rounds of the local Salvation Army, Goodwill, and
other independent shops to see what kind of relics are donated. Since eBay, Etsy,
and their kind have gained immensely in popularity, it is getting harder to find
anything useful other than clothes and kitchen wares. A few months ago Goodwill
had a 1910s vintage
cabinet-style Edison disc phonograph (as opposed to wax cylinder) that was in
very good condition, complete with a handful of styli and a couple old records.
The original finish over smooth mahogany and burl veneers had only a few scratches
and could easily be polished to look practically new. The metal hardware could have
stood a fresh coat of black paint due to nearly a century of oxidation. Even the
original nomenclature plate looked factory-new, and a clearly legible paper plaque
of operating instructions was embedded beneath a layer of shellac. I expected an
asking price of at least $500, but was shocked to see only $125 on the price tag.
Surely, I thought, the employee who affixed the tag must not have realized the value
of such a treasure of American history. Out of curiosity, I put a fresh steel needle
in the tone arm and placed a vinyl album gotten from the music area in the store
on the platter and cranked 'er up. The sound was barely discernable, so that ruled
out any possibility of justifying the purchase...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 220,000
per year (in six locations on each page, with >17,000 pages). That's pretty good
exposure for $300 per month. Some companies have expressed an interest in being
able to manage their advertising accounts themselves a la the Google AdSense program...
 Amplifier Solutions Corporation (ASC) is
a manufacturer of amplifiers for commercial & military markets. ASC designs
and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers
for low, medium and high power applications using Gallium Nitride (GaN), Gallium
Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs
operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film
designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility
in the town of Telford, PA. We offer excellent customer support and take pride in
the ability to quickly react to evolving system design requirements.
Wednesday the 20th
 This set of "Word
Charades and Riddles" was presented in the 1956 issue of The Old Farmer's Almanac.
The Charades puzzle solutions are each a single word formed from the combination
of two or more other possibly unrelated words inferred in the clues. They are not
portmanteaus, as in "coplay" for costume player, or "smog" for smoke and fog. Instead,
they are akin to "port," as in the left side of a boat, plus "age," as in years
since birth, combined as portage, being the act of carrying something. The Riddles
solution takes a more classic approach. Batman could figure out all of them...
 "The Power and Signal Distribution (PaSD)
SMART boxes (Small Modular Aggregation RFoF Trunk) are an essential component of
the Square Kilometre Array Low frequency (SKA-Low) telescope, currently under construction
at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory,
in Western Australia. The SMART boxes provide electrical power to the
SKA-Low telescope's 131,072 antennas and collect signals received from the sky
to go off-site for processing. The Development Journey The Engineering & Operations
team at the Curtin University node of the International Centre for Radio Astronomy
Research (ICRAR) designed and built the first set of 24 SMART boxes, which were
10 years in the making. 'The SKA-Low telescope will receive exquisitely faint signals
that have traveled across the Universe for billions of years,' he said. 'To detect
them, the SKA-Low telescope is being built in a pristine radio quiet zone far from
the interference created..."
 You can add to the long list of technical
wonders promised - and not delivered - to us by the end of the twentieth century
(this is now the 21st century, btw) a
three-dimensional (3D) television set. This 1958 article from Radio &
TV News magazine described efforts already made by the movie industry for generating
3D films that provided audiences with life-like projections that were designed to
shock their senses by having scary or dangerous objects suddenly hurled at them.
Pictures of a theater filled with people wearing the cardboard-framed red/blue stereoscopic
glasses are a very familiar symbol of the scheme known as stereoscopy. Another method
of 3D image perception was to use horizontal and vertical polarization along with
appropriately configured glasses to separate the images entering the eyes and relying
on the brain to convert a pair of two-dimensional pictures into a three-dimensional
image. Designers who came up with the ViewMaster line of viewers used a different
approach that used two cameras separated by some distance to record a unique perspective
of the same scene and presenting the two images to the viewer's eyes. It was the
most life-like scheme and, unlike the other described schemes...
 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
filters have been announced for September 2023: a 1750 MHz lowpass filter
with SMA Female connectors, a maximum passband VSWR of 1.3:1 and a maximum insertion
loss of 1.5 dB; a highpass filter a minimum rejection of 30 dB at 0–932 MHz
and maximum return loss of 2 dB; and a 2180-2520 MHz / 4380-5020 MHz
cavity duplexer with a return loss of 15 dB, and a maximum insertion loss of
0.3 dB. Custom RF power filter and directional couplers designs can be designed
and produced with required connector types when a standard cannot be found, or the
requirements are such that a custom approach is necessary...
 Throughout
the years, I have seen quite a few examples of art that depicts Phillip H.
Smith's famous Smith Chart, created by techie types. Its array of circles and semicircles
is attractive even to people who have no idea what it is. To wit, it is hard to
conceive of Pamela Anderson appreciating the gravity of the Smith Chart design on
the front of her T-shirt in this photo. From a purely technical standpoint, there
appears to be a lot of ripple in the response, which being biased toward the upper
half of the chart makes it inductive. Note from my "RF Engineers - We Are the World's
Matchmakers" design (to the right), where the bulk of the "Forbidden Region" areas
lie on the shirt. Hmmm, maybe she does understand the Smith Chart ... but I digress.
After an extensive Internet search using multiple search engines, I was able to
come up with these other examples of
Smith Chart Art™...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This
is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector,
waveguide, digital, analog, antenna, and other commonly used symbols for system
block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols
was exported individually from Visio in the EMF file format, then imported into
Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down
without becoming pixelated, so all the shapes can be resized in a document and still
look good. The imported symbols can also be UnGrouped into their original constituent
parts for editing. Check them out!
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
Tuesday the 19th
 The terms
"L-Pad" and "T-Pad" refer to the schematic circuit layout of the variable resistors
(potentiometers) used to form variable attenuators. An L-Pad uses a series and parallel
(shunt) resistor combination inserted between the source and load. A T-Pad uses
a parallel (shunt) resistor between two series resistors. Potentiometer values are
chosen to maintain a fairly constant input and output impedance throughout the attenuation
adjustment range. Resistance charts are provided rather than design equations, but
they are the same as those used for RF type attenuators of the same topography ("L,"
"T," "Pi"). Using the example for the T-Pad in this 1967 Radio-Electronics article
and the calculator I have on the webpage, plug 16 Ω into the Input Resistance
and Output Resistance fields and 4.375 dB into the Attenuation field, and it
will yield the resistor values shown below. The article's author stipulates 9.65 dB,
but that is voltage decibels. The RF calculator is for power decibels, so half the
voltage attenuation decibel value is entered...
 "Firefly Aerospace's Alpha rocket successfully
launched the U.S. Space Force's second operational tactically responsive space demonstration
Sept. 14, setting a record for flying within 27 hours of receiving launch orders.
The
Victus Nox mission, Latin for 'conquer the night,' was meant to demonstrate
the ability to rapidly acquire, build, integrate and launch a satellite. Boeing
subsidiary Millennium Space Systems built the spacecraft, which flew from Vandenberg
Space Force Base, in California. 'The success of VICTUX NOX marks a culture shift
in our nation's ability to deter adversary aggression and, when required, respond
with the operational speed necessary to deliver decisive capabilities to our warfighters,'
Lt. Gen. Michael Guetlein, head of Space Systems Command, said in a Sept. 15 statement.
With the satellite now in orbit, the team will work to begin operating it in within
48 hours..."
 As a life-long aircraft enthusiast, my attention
is always drawn to photos, drawings, and titles in articles dealing with any aspect
- but particularly a historical aspect - of aviation. This 1937 edition of Radio-Craft
magazine reported on the fledgling field of aircraft radio maintenance, and in particular
the opportunities presented to radio repairmen.
Aircraft electronics (aka avionics) have of course changed significantly over
the last 80 years. Accordingly, maintenance has become such a highly specialized
skill that other than swapping out entire pieces of equipment, relatively few facilities
exist that are qualified for the task. According to the article, at the time there
were a mere 5k privately owned airplanes. As of 2019, the AOPA estimated a total
of around 220k private aircraft (down from 224k in 2011), with 720k currently licensed
pilots (all categories) per the FAA...
 TotalTemp Technologies, a worldwide leading
provider of research laboratory and production temperature chambers and thermal
platform equipment, introduces their
Synergy Nano Temperature Controller. The Synergy Nano equips temperature chambers
and thermal platforms with capable and reliable controlling functionality. The flexible
Nano supports the ability to optimize equipment and processes. They are feature
rich while still being easy to use. Features include logging, configurable inputs
and outputs, alarms, displays, remote programmability options plus easy to build
and reproduce local test profiles. Controller is universal 120-230 Volts AC, whereas
platforms and chambers are typically not universal voltage. Size is a mere 5" x
8-3/16" x 8-1/2"...
 You wouldn't know it from the title, "The
Bell Bull Session," but this Carl and Jerry technodrama features a very interesting
subject - the Shive Wave Machine. The "Bull Session" part of the title is self-explanatory;
it's the "Bell" part that is a reference to Bell Telephone Laboratories, and specifically
to a gentleman named Dr. John N. Shive, who was Director of Education
and Training there. Being avid amateur radio operators and electronics experimenters,
Carl and Jerry were very familiar with the concept of traveling waves and impedance
matching. The Shive Wave Machine is an ingenious device that provides a visual physical
representation of a traveling wave and how an impedance mismatch generates a standing
wave within the metal tube transmission medium. A video of Dr. Shive explaining
his invention is embedded at the end of the article...
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...
 Withwave manufactures an extensive line
of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated
4-port vector network analyzer (VNA) calibrator, between- and in-series connector
adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes &
probe positioner. Special test fixtures for calibration and multicoax cable assemblies.
Frequency ranges from DC through 110 GHz. Please contact Withwave today to
see how they can help your project succeed.
Monday the 18th
 The Radio-Electronics magazine
folks who thought up the May 1961 issue's "What's
you EQ?" (Electronics Quotient) questions were in rare form; they called it
"a department of mental calisthenics." The first two of three were real posers,
both with multiple correct answers. Readers obliged the challenge with many proposed
solutions, so many that the June and July issues were required for providing enough
print space. The third, while fundamentally simple, can throw you for a loop if
you overthink the problem. I didn't come up with their solution. Going with the
not overthinking approach, mine suggested that there is nothing in the black box
(i.e., open circuit) and that the internal resistance of the voltmeter was 10 Ω,
which would cause 1 A to be drawn from the 10 V source while registering
0 W on the wattmeter. That's the solution with an absolute minimum of thought.
None of the readers - at least those who wrote in - came up with that...
 There are three fundamental
three dimensional
(3-D) coordinate systems (rectangular, cylindrical, and spherical), each of
which is a more convenient means for calculations depending on the configuration
of your model. For example, mapping points on the surface of a sphere using the
Cartesian coordinate system requires describing all three coordinates (x, y, and
z) in terms distance from each of the threes axis references. Doing the same in
the spherical coordinate system requires simply a radius and two angles. When you
start doing very complex calculations like those requiring calculus applications,
choosing the best coordinate system can make the difference between nightmarish
equations and relatively simple ones. Conversion formulas between the three fundamental
coordinate systems are as follows...
 Prior to the middle of the 19th century,
U.S. Post Office mailing rates were based on the number of sheets in a letter and
the distance it was traveling. In 1845, rates were based on the weight of a letter
and the distance it was going. Beginning in 1863, domestic letter rates became "uniform,"
that is, they were based solely on weight, regardless of distance. Benjamin Franklin
was appointed as America's first Postmaster General in 1775. The first postage stamps
were issued in 1847 According to the Bureau of Labor Statistics' (BLS) Inflation
Calculator, the inflation-adjusted price of the 1919 2¢ stamp is 35¢ in 2023 (a
17.5x, or 1650% increase). It is actually 66¢ as of July 9th. That's a 33x (3200%)
increase, nearly twice the rate of inflation...
 DigiKey has announced a back-to-school giveaway
with prizes up
to $1,000 of credit toward purchases in its store. That's $1,000 worth of any
products currently available on digikey.com. "Elevate your projects to another level,
or just keep the parts for your next great idea. Either way, we understand. We get
technical. If you are working on an engineering Senior Design project or Capstone
project, here is your big break." Second and third place winners get $500 and $250,
respectively. DigiKey ranked #5 in Supply Chain Connect's 2022 list of
top electronics suppliers...
 We have truly fallen as a great country.
This weekend, a USMC
F-35 stealth jet went missing in South Carolina after its pilot ejected. Officials
claim it just disappeared. A call went out to the public for assistance in finding
it. Yes, you read that right. As with many stories like this on, the reader comments
are the best part. Examples include "It's stealth so you'll never find it," Look
for it in Iran parked next to the supersecret
drone we let
them commandeer in 2011," "It's now flying over Ukraine," "Parked in Joe's garage
next to his 1967 Corvette," "The Mexican aliens snatched it," "It now identifies
as a bird and just flew away," "The official list of Jeffery Epstein Pedo Island
clients was aboard - you'll never find it." Fortunately, the pilot got out safely,
but bailing and saving your own hide out while your aircraft is left to go its own
way and potentially wreak massive damage and death to unwitting targets on the ground
seems undistingushed.
 Pop Quiz: What is the contemporary name
we have given to the
voltage dependent resistor (VDR)?* Although VDRs are nowadays used most familiarly
for overvoltage protection due to spikes on a power or signal line, they used to
be functional parts of television display and power supply circuits. Sylvania was
a prime manufacturer of VDRs, and field effect transistors - both junction (JFET),
and enhancement mode and depletion mode insulated-gate (IGFET, aka MOSFET). The
company used of all these devices back in the day as part of their effort to modernize
televisions and radio by abandoning vacuum tubes wherever possible. Thermistors,
silicon-controlled rectifiers (SCRs), and varactor diodes are also discussed in
this 1969 vintage Radio-Electronics magazine article. Answer:...
 Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your 728x90-px and 160x600-px Banner Ads are displayed on average 225,000 times
per year! 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. If you need your company news to
be seen, RF Cafe is the place to be...
 Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today - and don't miss the blog articles!
Sunday the 17th
 This custom RF Cafe
electronics-themed crossword puzzle for September 17th contains words and clues
which pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. As always, you will find no references to numbnut movie stars or fashion
designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page
links to hundreds of them dating back to the year 2000. Enjoy...
One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 220,000
per year (in six locations on each page, with >17,000 pages). That's pretty good
exposure for $300 per month. Some companies have expressed an interest in being
able to manage their advertising accounts themselves a la the Google AdSense program...
 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!
Friday the 15th
 The history of superconductors spans over
a century, beginning in 1919 with the discovery by Heike Kamerlingh Onnes, and has
led to significant advancements in the field of physics and technology. A superconductor
is a material that exhibits zero electrical resistance and the expulsion of magnetic
fields when it is cooled below a critical temperature. In other words, it can conduct
electric current without any loss of energy due to resistance, and it can also expel
magnetic fields from its interior. This phenomenon is known as superconductivity.
Superconductors have numerous practical applications, including in the construction
of powerful magnets for medical devices like MRI machines, high-speed electronic
circuits, and potentially even in energy transmission and storage systems. Superconductivity
is a quantum mechanical phenomenon that was first discovered in certain metals and
has since been observed in various materials, including ceramics and some specialized
compounds. This "The
1960's - Superconductivity's Decade?" article from a 1964 issue of Radio-Electronics
magazine is an optimistic view of the state of the art at the time. Sixty years
later, we're still not really "there" with superconductors...
 Note the vintage TE. "This is the second
part of our article '(Re)Discovering
the Lost Science of Near Field Measurements.' Part 1 of the article explained
what near and far field measurements entail, and that one-meter measurements are
very much near field. This second part picks up where Part 1 left off, and explains
the evolution of the earlier 12" and present-day one-meter separation measurements,
considerations in antenna selection, and the difference between antenna-induced
and field strength limits, and the evolution from one to the other. It is instructive
to compare and contrast how the limits in standards such as CISPR 22/32 were determined,
vs. those in MIL-I-6181. Such specifications state that a certain quality of baseband
signal results when a specified level of broadcast signal is received. From this
level, an EMI limit may be counted down using the signal-to-noise ratio required
to get the specified baseband quality. Thus, it is completely natural to specify
limits protecting such services in terms of field intensity, especially when the
compliance measurement is made in the far field (or nearly so)...
 I tried to find some information on "direct-impedance
amplification," but alas none could be located. At first, I suspected that it
being in the April edition of Radio-Craft magazine might have meant it
was a ruse on readers, especially since author L. Mitchell Barcus focused on
the nearly sub-audible portion of the sound spectrum down to around 16 Hz.
Careful reading of the article reveals, however, that his pièce de résistance was
designing the circuit with a minimum of biasing resistors, capacitors, and inductors
that might otherwise attenuate low frequencies. Success was in the form of direct
coupling of stages sans Rs, Ls, and Cs. I'm guessing the technique was not adopted
by the wider radio industry, except maybe for sound systems installed in aquariums
where whales and dolphins could appreciate faithful reproduction of 16 Hz tones...
 We at everything RF have published
our first eBook titled "Introduction
to 5G RedCap" to act as a comprehensive resource for anyone looking to learn
about 5G RedCap. This eBook covers the very basics of what this technology is to
more advanced topics that cover its use cases and compares 5G RedCap with existing
technologies and how to test this technology. everything RF has collaborated with
industry leaders like Anritsu, Keysight, Rohde & Schwarz, u-blox, Viavi and
Qorvo to ensure that the information provided is comprehensive and highly informative.
This eBook contains a wealth of technical content, well-researched whitepapers,
and valuable insights shared by experts in the field. 5G RedCap (Reduced Capability)
is the 3GPP IoT wireless specification designed to address several generic and specific
use cases for 5G NR. This new, lighter version - also known as 5GNR-Light - fills
the capability and complexity gap between the extremes in 5G today with an optimized
design for low/mid-tier use cases...
 Here is a quick, 10-question "Coil
Function Quiz" about common coil (inductors) applications, common at least in
1962 when it appeared in the June issue of Popular Electronics magazine. Don't be
scared off by the vacuum tubes that appear in three drawings. Just pretend they
are transistors - it won't affect your answers. One of the coil applications is
almost obsolete for most people as the nature of computer monitors and TV screens
has changed significantly in the last decade, so CRTs are rarely seen. If you are
one of the dwindling numbers of people who own and maintain vintage equipment, this
probably will not present much of a challenge...
 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...
 Empower RF Systems is the technological
leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat
Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers
incorporate the latest semiconductor and power combining technologies and with a
patented architecture we build the most sophisticated and flexible COTS system amplifiers
in the world. Solutions range from tens of watts to hundreds of kilowatts and includes
basic PA modules to scalable rack systems.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
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