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4 of the May 2024 homepage archives. Friday the 31st
 Even as recently as 1967, when this "Rotary
Stepping Switches - They're Everywhere" article appeared in Radio-Electronics
magazine, the vast majority of telephone switching stations used electromechanical
(EM) stepping switches. No computers were involved. If you have ever been inside
one of those facilities, the cacophony of clacking switches will be forever imprinted
on your memory. Nowadays all the switching is performed by computer-controlled solid
state devices. The only sound you hear is cooling equipment fans. The EM stepper
switch stations also had cooling systems with fans, but the contact clacking was
so loud that it drowned out the fans. Part 1, here introduces the basic configurations
and functions of rotary stepping switches. The December issue has Part 2, which
covers applications like counting, selecting, routing, and sequencing...
 Electronics World magazine often published
electronics-themed crossword puzzles. Unlike RF Cafe engineering crosswords
I created for two decades that use only technical words and clues, this one does
include some unrelated words. A couple clues I was surprised to see pertain to radar;
e.g., 32A: Small visible mark on a radar or scope screen, and 44A: Identification
Friend or Foe. Some words require a familiarity with technology of the era, but
you shouldn't have much trouble. You'll need to print this out on paper to work
it...
 "Researchers
in Korea have created the strongest
ever terahertz electromagnetic field: 260 MV/cm or 9x1013 W/cm2
equivalent peak – so powerful that it is classed as ionizing radiation. A 150TW
Ti:sapphire laser was used to convert optical energy into THz radiation in a 75 mm
magnesium oxide doped lithium niobate crystal wafer - a material with strong optical
non-linearity and high damage threshold. A process called phase-matched optical
rectification was used. If the optical laser pulse that generates terahertz radiation
propagates at the same velocity with the generated terahertz waves in lithium niobate,
then the output terahertz energy can continuously grow with the propagation distance,
according to the team..."
 Lee de Forest, upon whom was conferred
the honorary title "Father
of Radio" by Radio-Craft magazine editor Hugo Gernsback (and others,
except those who accord that title to Guglielmo Marconi), exemplifies personal traits
of most great inventors: high intelligence, stick-to-itiveness, courage, passion
for his subject, determination, and a willingness to endure a lot of personal and
financial abuse. The January 1947 issue of Radio-Craft magazine celebrated the 40-year
anniversary of Mr. de Forest's invention of the Audion vacuum tube by
including a large number of articles by various authors who knew him personally
and attest to his greatness. I will be posting a few of those pieces, and you will
probably be shocked at some of the shenanigans that went on by conniving people
and naysayers who tried to deny de Forest due credit. For example, based on
his work to make more sensitive receivers a judge in a lawsuit brought by Marconi
strictly enjoined him...
•
AM Radio Momentum Seems Unstoppable
• CQ Magazine Publisher
Dick
Ross, K2MGA, SK
• Nokia, NASA to
Take 4G to
the Moon
•
Radar Module Market Projected to Reach $36B by 2029
•
Coffee Is Anti-Aging (I might live forever)
 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...
Thursday the 30th
 In the years between graduating from high
school and the time I enlisted in the USAF that I worked as an electrician and did
many in-home service calls, never once did I encounter a situation like our hero
Pete did here. In fact, I doubt many television and radio servicemen ever did, either.
According to most of the anecdotes related by electronics servicemen, homeowners
were more likely to be abusive than dotingly appreciative. In the era (c1962) when
this
Precision Apparatus Model CR-60 Picture Tube Tester and Rejuvenator advertisement
appeared in Radio-Electronics magazine, people were crazy about their televisions,
especially as color broadcasts occurred more frequently, and many got helplessly
depressed when the set went on the blink...
 This is the last of a series of articles
on printed circuit boards (PCBs) that appeared in the October 1969 issue of
Electronics World magazine, reporting on the latest and greatest advances in
printed circuit board technology. Author Gaetano Viglione, of Sanders Associates
(bought by Lockheed Martin in the 1980s and now owned by BEA Systems), reported
on the state of the art of flexible printed circuit wiring.
Multi-layer flexible PCBs were limited to only a few. Sanders did a lot of aerospace
and military electronics systems and was a leader in the field. In those days, the
larger electronics manufacturers had their own in-house PCB design and fabrication
capability. With most PCB fabrication being done out-of-house nowadays, companies
like
San Francisco Circuits, who specialize in PCB fabrication, can be contracted
to supply multi-layer flexible printed circuits for static and dynamic 3D applications...
 KOA Speer Electronics, a leading supplier
of
passive electronic components in the Americas, announced it has received TTI's
2023 Diamond Award, Best Quality Award, and Supplier Excellence Award. The TTI Americas
Supplier Excellence Award Program represents the highest recognition possible of
a supplier's performance within TTI. KOA Speer has been a Supplier Excellence Award
recipient in 28 of the 29 years that TTI has presented the awards. In addition,
KOA Corporation achieved the Global Operations Excellence Award for the very first
time. Melanie Pizzey, Corporate Senior Vice President, TTI, Inc. stated "KOA has
demonstrated global consistency in their dedication to continuous improvement and
exceptional customer service. On behalf of the TTI team, thank you to all employees
of the KOA organization for another year of outstanding global support of TTI...
 Magazines usually provided at least a brief
description on the circuit functionality for each of the radio models presented
in schematic format. The April 1947 issue of Radio News magazine published
schematics and parts lists for six sets, including this for the
Air King Model 4604D, but not a word about any of them accompanied it. The Air
King Model 4604D thumbnail image is from Ron Potter's Attic website. These are posted
as part of my ongoing effort to make the information available to those who repair
and/or restore vintage vacuum tube radio sets. Services like SAMS Photofact®, which
began operation in 1946, is still an excellent source of the most detailed data
available...
 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 Banner Ads are displayed on average 280,000 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...
Wednesday the 29th
 The early 1960s was a time of big change
in electronics as the industry transitioned from vacuum tubes to solid state devices,
commercial broadcast radio moved from AM to FM, and color television broadcasting
was overtaking black and white. Airwaves were quickly becoming crowded as engineers
and scientists raced to expand operational frequencies past the hundreds of megahertz.
Spectrum needed to be protected against indiscriminate use and abuse. The FCC expanded
its imposition of licensing for users to help assure effective coexistence. This
1962 issue of Radio-Electronics magazine's "News Briefs" column reported
on plans for new licensing. Also, the introduction of
higher numbers of women into engineering fields was abetted by highlighting
successful examples, like Miss Sylvia Welker at the White Sands Missile Range. Amplifier
noise figures below 1 dB were a rarity in the day, so a 0.9 dB parametric
amplifier...
 Note:
Cat state is named after Schrödinger's
cat. "The
cat qubit, is a route to fault-tolerant quantum computing. Boson 4 marks the
first time a cat qubit has become available to the public. Quantum bits suffer from
two types of errors, bit-flip and phase-flip. Each error occurs dozens of times
per second in superconducting qubits in the best cases, usually far more often.
IMG_0071-150x150.pngThe Boson 4 chip extends the bit-flip time to well over seven
minutes - claimed to be a four orders of magnitude improvement over the state-of-the-art
and a world record for superconducting qubits. Next iterations will focus on improving
the phase-flip performance and enabling multi-qubit operation. Fault tolerance is
now seen as a mandatory..."
 Magazines usually provided at least a brief
description on the circuit functionality for each of the radio models presented
in schematic format. The January 1947 issue of Radio News published schematics
and parts lists for six sets, including this for the
Admiral models 6EI and 6EIN, but not a word about any of them accompanied it.
These are posted as part of my ongoing effort to make the information available
to those who repair and/or restore vintage vacuum tube radio sets. Services like
SAMS Photofact®, which began operation in 1946, is still an excellent source of
the most detailed data available...
 Here is an idea that you makes you wonder
why someone hadn't thought of it long ago. Innovative Power Products' (IPP)
Cool Chip is designed to draw heat from one location that is too hot and move
it to a different location that can absorb the heat. These devices are manufactured
on a highly thermally conductive ceramic substrate (Aluminum Nitride, AlN) that
is electrically isolated with low capacitance and safe to use. The terminals are
gold-plated over nickel, making them easy to solder with many different alloy types.
These devices are ideal for small, compact areas with high heat concentrations,
intended for both military and commercial applications. The Cool Chips come with
or without an edge wrap in three sizes: 0805, 1010, and 1206. Cool Chips are made
in the USA with the same high quality that IPP is known for...
 We really have it good today compared to
the early days of the semiconductor revolution. Most of the most difficult problems
were solved long ago. Point contact devices were still fairly commonplace even in
1964 when this ad appeared in Electronics magazine. Recall that the very
first manufactured
solid state diodes and transistors were the point contact type that were encapsulated
in glass with a space gap where the contact was made. That left the device vulnerable
to vibration and impact damage and to contamination if the hermetic seal failed
between the metal lead and the junction(s). Unitrode claims to have been the first
to eliminate that issue with essentially a fully bonded package. Keep in mind, however,
that even the early semiconductor device packaging was no worse than the vacuum
tubes that they replaced, since the tubes also suffered from the same vulnerabilities
due to their construction...
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 Banner Ads are displayed on average 280,000 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...
Tuesday the 28th
 Did you know the 1961 Lincoln Continental
that President John F. Kennedy was shot while riding in had a transparent Plexiglas
roof available? If it had been installed that fateful day in November of 1963, would
the bullet have missed the president or maybe the shooter would not have even tried
for the shot. You might think the car would be referred to as Presidential Limo
One or some code name similar to Air Force One (airplane), or Marine One (helicopter),
but the best they could come up with was
X-100. There was also an official presidential yacht (Sequoia) up until 1973.
I highlight this feature from a 1961 issue of Popular Science magazine
primarily because it mentions a pair of radiotelephones - one with a scrambler for
super-secret communications. The car, by the way, was a rental ($500/year), and
was actually owned by Ford Motor Company...
 Even in the early days of
"computer-designed" printed circuit boards, the software was sophisticated enough
to take a circuit net list and perform a rudimentary auto-routing all of metal traces,
component solder pads and through holes, using a set of defined design rules for
line width and spacing, component size, number of layers, etc. Manual tweaking was
usually needed after the initial run, but even today, especially for high frequency
PCBs, some manual adjustment is needed to help ensure first-pass success of a layout.
According to author Bauer, as many as 22 layers had been accomplished at the time
of the article's printing in a 1969 issue of Electronics World magazine.
Numerically controlled machines were already being used to produce artwork and drill
through holes. What kinds of computers did the heavy computations in the day? "A
12 x 12 inch board with 50 thousandths of an inch grid requires 120,000 bytes of
memory. This memory capacity is supplied by a medium- to large-scale computer...
 The
World Administrative Radio Conference (WARC) is associated with the International
Telecommunications Union (ITU). It is hard to pin down exactly when the organization's
name official became the WARC since it is no longer a separate entity, and good
luck locating a definitive history on the WARC proper. The closest I could come
to determining a time when it was first referred to as the World Administrative
Radio Conference was from this list of all radio conferences on the ITU website.
The Geneva 1967 WARC is it. Previous events did not include the word "World" in
them, from what I could find. Please let me know if you have another authoritative
source. This 1971 WARC for Space Communications was the first to emphasize allocation
of frequencies to satellite operations...
 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, and
more. Page templates are provided with a preset scale (changeable) for a good presentation
that can incorporate all provided symbols...
Monday the 27th
 Hugo Gernsback wrote in his June 1962 issue
of Radio-Electronics magazine editorial "Earth
Signals on the Moon" editorial that, "Within the next few years - certainly
before 1970 - men will have landed on the moon, opening up a vast new world." That
was a year after John F. Kennedy made his famous "man on the moon" speech.
As he was wont to do, Mr. Gernsback accurately predicted the series of events
that would lead up to the first manned moon landing. He mentions the need for automation
to achieve a controlled, soft landing on the lunar surface because of the time lag
for radio communications between the Earth and the moon - a little more than a second
each way - which is not fast enough for a remotely controlled landing of an unmanned
craft. He also addresses the necessity for accommodating the Doppler frequency shift
due...
 These couple
tech-themed comics appeared in the June 1969 issue of Electronics World
magazine. The one on page 52 is a bit short-sighted even for its era given that
any advanced civilization would likely no longer use vacuum tubes. For that matter,
most first-world peoples on Earth were pretty much out of the vacuum tube realm
by 1969. New TVs (except the CRT) and radios were almost exclusively solid state.
The comic on page 61 made me chuckle out loud when I saw it. That one is worth printing
out and framing to hang in the lab or outside an electronics professor's office
door...
 According to the Oxford English dictionary,
the definition of an anagram is: a word or phrase made by using the letters of another
word or phrase in a different order; e.g. "Neat" is an anagram of "a net." Therefore,
the title of this Electronics World magazine puzzle appears to be misnamed.
Sometimes an anagram crossword puzzle is created in which the clues are in the form
of anagrams, but even that is not the case here. With any due apologies to author
Comstock, I hereby re-title this a "High-Fidelity Crossword Puzzle." The "high-fidelity"
part is entirely appropriate since it refers to the musical nature of the clues
and words. As mentioned previously, the late 1950s through the early 1980s was a
major era for interest in high fidelity radio receivers and playback gear. It represented
the transition from powerful vacuum tube amplifiers to hybrid amplifiers, clear
through to high power transistorized amplifiers. "Man caves" of the day were outfitted
with the latest and greatest stereo gear, and might have included a 25" television,
but that was an optional feature. Being able to measurably add to the permanent
deafness of yourself and your buddies was a measure success and increased social
status...
 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+ 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...
Friday the 24th
 The fundamental
principles of sonar (sound navigation and ranging) and radar (radio detection
and ranging) are very similar. Oddly, the author never makes the comparison, and
neither does he mention the makeup of the acronym. Although I am no sonar expert,
I did work as an electronics technician with sonar system components while at the
Westinghouse Oceanic Division in Annapolis, Maryland, back in the 1980s. And, as
you might know, I was an Air Traffic Control Radar Repairman in the late1970 - early
1980s, so I have some experience there, too. While both sonar and radar have their
own unique challenges regarding operational environments, I have to say the sonar
system designer has more obstacles to overcome than does his radar counterpart.
Factors affecting signal propagation which can lead to uncertainty in position,
size, and speed are water salinity, temperature, pressure (at great depth), turbidity,
turbulence, including often traversing multiple gradients between the source and
the target. Wavelengths useful at long distances are too long for fine resolution
images, but for close-up inspection, ultrasonic enable near photographic resolution.
•
Collegiate Amateur Radio at 2024 Hamvention
•
China's Hi-Tech Progress Reshaping Global Politics
•
Marconi Radio Awards Nominations Open
•
FCC Fines Carriers for LBS Information Misuse
• The
U.S.-China Tech Cold War
 Francis A. Gicca, manager of Raytheon's
Space Communications Systems, published a very extensive two-part article in
Electronics World magazine in 1969. Part 1 covered Score through
Intelsat II satellites which launched between from December 1958 and December
1968, respectively, in the July 1969 issue. Part 2 begins with Intelsat III,
which commenced operation in September 1968. Rather than reiterating the article's
contents, I will offer an anecdote about the altitude used by geostationary satellites,
which is 22,300 miles. In the early 1990s, I worked for a few years at COMSAT Laboratories
(Communications Satellite Corporation, famous for involvement in both Intelsat and
Inmarsat), in Clarksburg, Maryland. The mailing address there was 22300 Comsat Drive...
 Winged
Shadow Systems has developed a solid state
electronic altimeter called the How High™ that plugs into a spare receiver channel
for power, and provides altitude readings between 50 feet and 7,000 feet above ground
level. The heart of the system is the SM5420 pressure sensor, by Silicon Microstructures.
It is a micromachined structure molded in an 8-pin SOIC plastic package. Here is
the datasheet. Per the manufacturer, "The SM5420C is a small outline SO-8 packaged
pressure sensor. The sensor uses SMI's SM5108C micromachined, piezoresistive pressure
sensing chip that has been optimized to provide the highest possible accuracy for
a package of this size..." News
Flash: I set a personal thermalling altitude record of 1,267 feet
in my 85% Aquila glider on May 23, 2024!
 If you or someone you know is just starting
in the realm of radio and want a really nice pictorial presentation of the basics
of
radio wave propagation, then this one-page article from a 1935 edition of
Short Wave Craft magazine is just what you need. Formula phobia will not
be an issue for anyone since no equations are presented. The fundamentals have not
changed in the intervening 89 years, and this same sort of analogy is still used
in introductory physics classes and books today. Note in Figure 7 that the
antenna for the airplane is shown being dragged behind. Back in the day, a long
antenna was spooled out once in the air, and cranked back in before landing. If
the pilot forgot to reel the antenna in, it could get yanked off by a tree upon
landing. CW (Morse code) was the dominant form of air-to-ground communications...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's
Matchmakers" Smith chart design. These would make excellent gifts for husbands,
wives, kids, significant others, and for handing out at company events or as rewards
for excellent service. My graphic has been ripped off by other people and used on
their products, so please be sure to purchase only official RF Cafe gear. I only
make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way
to help support RF Cafe. Thanks...
Thursday the 23rd
 90 miles of wire in an average home is a
lot of wire. That includes not just the wire used for supplying 120 VAC receptacle
and light lines within the walls and ceiling, but also the wire in motors, relays,
and transformers in appliances and various subsystems (HVAC, attic fans, shop tools,
etc.). When this article appeared in Popular Science magazine in 1961,
the average size of an American home was around 1,300 square feet. In 2024, it is
around 2,600 square feet. That's a doubling in size with fewer people per household
(mine is smaller than the 1960 standard). The typical house now has more AC wiring
in it due to electrical code changes requiring ceiling lights in all rooms, more
receptacles, more feeder circuits, etc.
Adding a ground wire increases the copper in a length of Romex by 33% to 50%.
Most kitchens have more appliances on the counter, and the proliferation of cordless
tools has added significantly to the number of motors. Most houses did not have
air conditioning in 1961, so add a compressor motor...
 When designing filters, be they lowpass
(LP), highpass (HP, bandpass (BP), or bandstop (BS), you begin with prototype values
of capacitors and inductors using an impedance of 1±0j Ω and a
frequency of 1 rad/s. From there, you need to
scale the components for whatever impedance and frequency you need. Most filters
we use are 50±0j Ω and then scaling frequency is the cutoff for LP and
HP, and the fencer frequency for BP and BS. Of course these days nearly everyone
uses software to do the heave lifting, but if you're old school or are in school
and need to do it manually,
Espresso Engineering Workbook (free download) now have a page to do that for
you...
 Here are a couple more
electronics-themed comics from 1947 issues of Radio-Craft magazine.
Artist Frank Beaven, who created a huge number of comics and advertisements (e.g.,
Eveready batteries, Zippo lighters) for technical and other types of publications
(Saturday Evening Post, New Yorker, Esquire), did both of them. Beaven must have
a fan base since many examples of his drawings are offered for sale on eBay. Most
of his comics credit reader suggestions as the basis for the subject. I have to
admit to not really "getting" the gag in the top comic. Maybe Sinatra's voice strained
the frequency response of simple tabletop radios of the day. The bottom comic is
one of a series entitled "Radio Terms Illustrated," in this case "High Potential"
(get it?)...
 "This article presents the derivation of
the radiated far fields from a
Hertzian dipole antenna above the ground plane using image theory. An electric
dipole, often referred to as a Hertzian dipole consists of a short, thin wire of
length l carrying a constant current positioned symmetrically at the origin of the
coordinate system and oriented along the z-axis. Ideally, the wire is infinitely
short; practically, a wire of the length l << λ /50 (λ = wavelength) can be
considered a Hertzian dipole. The far field of a Hertzian dipole has only a θ component
(in a spherical coordinate system) and is given by Eq. 1. In image theory, a radiating
antenna (actual source) is placed at some distance h from a perfect conducting plane..."
 The origin of the saying "Everything old
is new again" is credited to sources ranging from the Bible to Shakespeare to Mark
Twain. It might be one of the most oft-repeated phrases about life. The topic of
this editorial from a 1972 issue of Popular Electronics magazine is a prime example
of why people like me invoke the aforementioned dictum. For as long as I have been
aware of the
state of engineering and technology, opinion writers (aka "journalists") have
lamented the sorry condition of education in that it cannot motivate and produce
a qualified new crop of replacement engineers, scientists, technicians, doctors,
nurses, chemists, and other white collar workers (I can't recall ever hearing of
lawyer shortage, unfortunately). Looking back at how the "shortages" have been handled,
a large portion of the deficit was rectified by importing foreign talent rather
than...
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+ 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...
 KR Electronics has been designing and manufacturing custom filters
for military and commercial radio, radar, medical, and communications since 1973.
KR Electronics' line of filters
includes lowpass, highpass, bandpass, bandstop, equalizer, duplexer, diplexer, and
individually synthesized filters for special applications - both commercial and
military. State of the art computer synthesis, analysis and test methods are used
to meet the most challenging specifications. All common connector types and package
form factors are available. Please visit their website today to see how they might
be of assistance. Products are designed and manufactured in the USA.
Wednesday the 22nd
 Mr. E.D. Clark added these three circuit
posers to his increasingly large number of "What's
Your EQ?" series of columns, this one appearing in the June 1962 issue of
Radio-Electronics magazine. While many can be real head-scratchers, the
first problem is not too much of a challenge. The resistor and capacitive reactance
circuit should also be a piece of cake for even a first-year student. It's a standard
voltage divider except you need to account for the phase shift (-90°) of the capacitor,
which requires using the magnitude of the series combination. I had to admit that
the author's solution to the 1 μs pulse from a 2 μs using only a simple
passive device eluded me. I was thinking in terms of an RC differentiating circuit
of some sort with phase delays, but a much simpler method is possible. You'll need
to think "out of the box" - the spare parts box, that is...
 "Remcom's
XFdtd and Wireless InSite EM simulation software packages provide a complete
solution, from system and MIMO antenna design through performance assessment in
realistic, simulated environments, and planning for deployment in 5G networks. Their
mission is to provide accurate solutions, optimized for performance to help customers
reliably predict how their systems will behave in the real world. Through active
research and development, Remcom has remained a leader in modeling and MIMO simulation
technology for 5G and advanced wireless communications. 5G is pushing the boundaries
of wireless communications and wireless device design. Significant innovations are
needed in order to accommodate increased requirements for Enhanced Mobile Broadband,
Massive Machine-Type..."
 You've heard of the World's Fairs, the most
familiar probably being the 1933 Chicago World's Fair where the theme was "A
Century of Progress." World's Fairs have been held in various cities worldwide
since the late 1790s. In 1929, the World's Fair was held in the United Kingdom,
but the "Radio World's Fair," which began its annual run in 1924 (click on stamps
thumbnail), was held in New York City. Surprisingly little exists on the Internet
about the events. It was more of a trade show to introduce new products than it
was a fair, as can be seen from the photos. Radios with decorative wooden cabinets
were becoming popular as the number of commercial broadcast stations was growing
rapidly. Remote control in the day meant a handheld unit with a cable attached to
the main system. Crosley introduced its first gendered radio model - the Monotrad
(see photo).
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to announce
the
Exodus AMP2099C, a rugged ultra-broadband SSPA designed for all applications.
It supports a frequency band of 500 MHz to 6.0 GHz, with 150 W minimum
power and 53 dB of gain. Excellent power/gain flatness as compared to other
amplifiers. Forward/Reflected power monitoring, VSWR, voltage/current/temperature
sensing for superb reliability and ruggedness. The nominal weight is 23 kg
in a compact 4U chassis 7"H x 19"W x 22"D...
 When you read a lot of tutorials about introductory
electronics on the Internet, most are the same format where stoic, scholarly presentations
of the facts are given. Those of you who don't have enough fingers and toes to count
all of the college textbooks like that which you have read know of what I speak.
When hobby articles are written in a similar fashion, it can quickly discourage
the neophyte tinkerer or maybe even a future Bob Pease. The American Radio Relay
League's (ARRL's) QST magazine has printed a plethora of articles over
the years that are more of a story than just a presentation of the facts. My guess
is the reason is because often the authors are not university professors who have
forgotten how to speak to beginners. This 1944 article on basic calculations for
AC series and parallel circuits is a prime example; everything still holds true
today.
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.
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news to be seen, RF Cafe is the place to be...
 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. We have >500,000 RF and Microwave passive
components we can ship you today! We offer Quality Precision Parts, Competitive
Pricing, Easy Shopping, Fast Delivery. We're happy to provide custom parts, such
as custom cables and adapters, to fit your needs. Centric RF is currently seeking
distributors, so please contact us if interested. Visit Centric RF today.
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About RF Cafe.
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