See Page 1 |
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4 | of the June 2024 homepage archives. Friday the 7th
 Not to disrespect Gustav Kirchhoff's accomplishments,
but his two eponymous laws seem so obvious that you might wonder why they even need
to be stated, much less be named after someone. The equivalent for the oft-used
water in a hose analogy would be as follows: (#1) The volume of water entering the
common port of a manifold is equal to the sum of the water exiting all the other
ports. (#2) In a closed system, the sum of the the pressure drops (e.g., constricted
pipe) and pressure rises (e.g., water pump) is zero. In fairness, when Mr. Kirchhoff
formulated his laws in the middle 19th century not many people were familiar with
electric circuits, and instruments for making certified measurements with enough
precision to validate the claims were not readily available. This 1962 Radio-Electronics
magazine article introduces
Kirchhoff's current law and voltage law. Remembering and applying them does
make writing equations for multi-loop circuits much simpler...
 Here are a couple
tech-themed comics that appeared in the October 1969 issue of Electronics
World magazine. I like the one with the two guys applying for a patent best.
Note the size difference. Of course the mother-in-law comics are always funny. There
is a huge list at the bottom of the page of links to other comics I have posted
over the years. BTW, people have asked why I separate the text from the image. The
answer is simple: If someone finds the image using an image search, he/she has to
actually visit the webpage to get the punch line. Does that make me a bad person?
• U.S. Revokes
Huawei Chip Export Licenses
• FCC Investigates
Unauthorized Undersea Cables
•
463,000 Kia e-SUV Should Park Outside Pending Recall
•
Ofcom Plan for Hybrid Sharing of Upper 6 GHz Band
•
Quantum Computing Market on 17% CAGR to $1.8B in 2029
 Audio distortion is most often expressed
as
total harmonic distortion (THD) as opposed to intermodulation distortion (IMD).
As the name suggests, THD is a measure of harmonic power content relative to the
fundamental frequency (a single tone) from which harmonics are created. IMD on the
other hand, is generated from the nonlinear mixing of two or more tones, with the
products being non-harmonically related to the original tones. The author's discussion
of audio frequency IMD applies equally to radio frequency IMD. Intentionally generated
harmonic components can enhance sound quality due to being consonant, whereas IM
products create dissonant tones not directly related to the originals. Audio amplifier
frequency vs. power specifications typically include the sum of total harmonic distortion
and noise (THD+N), signal-to-noise ratio (SNR)...
 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 280k
per year (in eight locations on each page, with >17k pages)...
Thursday the 6th
 Sometimes one of the most interesting parts
of a magazine is the Letters to the Editor. Most of the time it is composed of notes
of appreciation for publishing a certain article, or appreciation for the works
overall. Occasionally, a reader will sound off with a criticism of and article -
some more polite than others. The magazine editor will usually give the author a
chance to respond immediately after the challenge to content veracity. Such was
the case in the March 1967 issue of Radio-Electronics magazine when a Zenith
company engineer wrote to correct a previous article's claim regarding
linear phase filter design in FM radio systems. Author Crowhusrt happened to
mention in an AM-to-FM converter circuit that a Zenith scheme might not be the best
approach for the application (versus a General Electric scheme). Zenith's Huenemann
meant to set the record straight, but Mr. Crowhust did an admirable job defending
his writing. Nerd wars...
RF Cafe website visitor Joseph B. sent me this note in regard to this 80th
anniversary of the D-Day invasion:
"Below are a few links regarding D-Day (which is today). The first [Radio
Comms] is a link to how radio comms were setup during the invasion, the second
[Broadcasts Link]
is a collection of news broadcasts on the day of the event, and the third is an
article about local radio technician and baseball hero,
Jim Pinder,
who stormed Normandy beach carrying 52 lbs of radio equipment. Lastly, a very
heartfelt "Thank you!" to all who served and to those who gave their lives.
 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 Model AMP2145D-LC, a 18.0-40.0 GHz, 80 W Solid State
Amplifier is another industry first from Exodus. Designed for Broadband EMC &
Lab Testing, Mil-Std 461 (RS103) standards as well as other High-Power Applications.
Exodus Model AMP2145D-LC is a compact 6U design providing outstanding power/gain
flatness, Forward/Reflected power monitoring in both dBm & watts, VSWR, voltage/current
and temperature sensing for superb reliability and ruggedness. Unprecedented reliability
compared to TWT's, with 49 dB gain including gain control, and -20 dBc
harmonics...
 When I saw this Hughes Research and Development
Laboratories employment ad in a 1955 issue of Radio & Television News
magazine, I wasn't sure how to take it. The text of the ad makes no reference to
the bar graph and the weird drawing.
Note the "bottle" is actually a slide rule. The graph can be interpreted to
indicate that the more education a person has, the less likely he is to have children.
If the typical age of the respondent is in the twenties, then that might reflect
how people still in school to earn a higher degree would not be having children.
It might also show that people with higher degrees focus more on their careers than
on having a family. If you extrapolate the graph backward, does it imply people
with an Associate's degree might average 1.5 children, those with just a high school
diploma have about 1.7 children, and high school dropouts average maybe 2.0 kids...
 "ED2 Corporation, a company that designs
a range of products in electronics and wireless communications, has developed Advanced
Glass Packaging Technology (AGPT™) that will enable
heterogeneous integration of electronic components and modules. The AGPT technology
is based on using Synthetic Quartz (Fused Silica) as the substrate material that
exhibits excellent thermal, electrical, and optical properties. It enables ultra-small
feature sizes, excellent high frequency response, allowing for tight integration
and supporting fabrication as a wafer-level process, for scale and cost. The heterogeneous
integration of components is facilitated..."
 Today is the 80th anniversary of D-Day.
Maybe it comes from having crossed the half-century Rubicon, but with increasing
frequency I find myself seeking out vintage magazines to learn how the world used
to be. I am a realist who has no misconceptions about how things used to be idyllic
and that today is utter debauchery, but it is apparent from a lot of the publications
that we surely have changed significantly in the last 50+ years - better in some
ways, worse in others.
Technologically we are
much better off; societally, not so much. For many years I have been purchasing
of WWII era QST and other electronics magazine titles listed on eBay. I
do the same thing for vintage model magazines on my Airplanes and Rockets website.
Selected articles and advertisements are scanned...
 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...
Wednesday the 5th
 Probably most people of my era (nee 1958)
had their introduction to a
track ball in a bowling alley or convenience store where a Missile Command (Sega)
arcade machine installed. Most machines had either pushbutton or joystick directional
control, but for the fast-moving action of Missile Command, you really needed the
track ball. I never got really good at it (Asteroids and Donkey Kong were my area
of expertise), but the guys who were could whip that surface defense gun at lightning
speed and pinpoint accuracy as the cascade of missiles came raining down from space.
Their firing fingers would be a blur as they timed the barrage of shots with the
track ball. Ah, those were the carefree days! A quarter was a lot to drop into a
machine, but there were much more addictive, destructive, and expensive habits to
consume you. This 1962 issue of Radio-Electronics reports on what would have been
one of the first track ball designs. It was developed by Hughes Aircraft. The mechanism
was purely electromechanical since there were no laser or even infrared diodes to
use for counting light pulses through a perforated encoding disk...
 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 June 2024 - a 2205.5 MHz cavity bandpass
filter with a bandwidth of 15 MHz, a 2201.5 MHz cavity bandpass filter
with a 6 MHz 1 dB bandwidth and an insertion loss of 2.0 dB, and
cavity bandpass filter with a 90 MHz 1 dB bandwidth. 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...
 This
electronics analogy quiz is a little easier than many of the others created
by Robert Balin and published in Popular Electronics magazine because all
of the electrical and mechanical objects depicted here are very familiar. The concepts
might seem trivial to those of us who have been immersed in the science for decades,
but I for one can remember when first hearing these analogies how helpful they were.
Not only that, but I also recall during physics and mechanics courses in college
being amazed at the similarity of equations shared by electrical and mechanical
processes. Wikipedia has a huge page describing many of the most familiar mechanical-electrical
analogies...
 The
Yole Group has provided a comprehensive review of
UWB technologies, highlighting and comparing the solutions implemented in smartphones
by leading companies like Apple, Samsung (NXP), and Google (Qorvo). In the past,
Yole Group conducted extensive analysis on numerous FEMs and components to provide
insights into the RF market within specific flagship smartphones. Each Yole Group
report focuses on a specific topic, whether it's the evolution of a particular player,
a specific technology, or a comparison of flagship devices. This year, Yole Group
pursues its investigation in this domain, offering various technical and cost comparisons
of smartphone RFFEMs. The report, Ultra-Wideband Comparison 2024, delves into the
technology and cost aspects related to UWB connectivity in consumer applications.
It offers an overview of UWB technologies, comparing solutions for smartphones used
by major companies...
 This photo of
Ray Dolby with one of his prototype noise reduction circuits is probably the
most widely published of him and therefore the most iconic of the Dolby noise reduction
system. Audiophiles of the era (and today for that matter) immediately recognize
the man who took the hisses and pops out of their beloved music. I always like to
keep in mind when reading articles like this one in a 1971 issue of Radio-Electronics
magazine is that when it was originally published, Dolby had not yet become a household
word and news of his accomplishment was just getting out. Many articles, books,
and research papers have been written on how the Dolby system works. At least five
of them from the groundbreaking era have been posted here on RF Cafe, so you can
get some insight into the excitement. The technical term "companding" (compressing
and expanding) was being seen in print for the first time. Unlike today when such
signal processing...
 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...
Tuesday the 4th
 Time to put on the thinking cap again for
three more "What's
Your EQ?" circuit challenges, compliments of Radio-Electronics magazine
in May 1962. The first is a classic "black box" type problem which, from reading
its description, involves some sort of resonant circuit. that's all I'll say on
that. The next, called "An Easy One?" should, by the way it is drawn, be a clue
that it might be easier to solve if you re-draw it to make a familiar-looking circuit.
Hint: Summons the spirit of Sir Charles Wheatstone. Just the name of the last one,
"Iterative Network," is enough to induce a cold sweat. As with most of these "What's
Your EQ?" problems, successful completion of a first year college circuits course
is plenty to get through them. A few are better attempted by people with hands-on
experience troubleshooting circuits, but don't let that scare you off...
 Once transistorized computers made desktop-sized
systems a reality, the sure eventuality of humans being replaced by their electronic
equivalents became a popular theme of media pundits. News reports and "special features"
on TV at the same time scared citizens concerned for their jobs and assured them
that by the year 2000, humans wouldn't need to work anymore anyway because
computers and robots would be doing everything for them. The last millennium
crossover occurred nearly a quarter century ago now, and looking back it is true
that computers and robots have usurped a lot of what used to be done manually, but,
as Mac presciently predicts in this story, along with the changeover has come a
plethora of new high tech jobs both for creating and maintaining those systems.
There are still many service type jobs that will never be replaced by automation,
but one aspect of domestic job losses not envisioned by Mac McGregor (Frye's alter
ego) is the offshoring of call service centers, doctors in Kazakhstan reading our
medical x-ray and MRI images, and all the design work being done in countries most
people never knew existed - using equipment...
 "Engineers at the University of California
San Diego have developed a new technology that has the potential to make the
extended reality (XR) experience smoother and more seamless. The technology
consists of an asset localization system that uses wireless signals to track physical
objects with centimeter-level accuracy in real time and then generates a virtual
representation of these objects. Applications of this technology range from enhancing
virtual gaming experiences to improving workplace safety. The team, led by Dinesh
Bharadia, a professor in the Department of Electrical and Computer Engineering at
the UC San Diego Jacobs School of Engineering, presented the technology..."
 Prior to atmospheric sounding rockets and
orbiting satellites, all information gained and theories developed on the nature
of Earth's upper atmosphere and its interaction with
electromagnetic waves (radio in particular) were purely academic, not the result
of empirical data. That is not to say the theories were wrong (although some were),
just that they were incomplete. For that matter, even today there is still much
to be learned and, according to an excellent article in the October 2015 issue of
the ARRL's QST magazine titled "Five Myths of Propagation Dispelled", there
is still a lot of misinformation being believed and promulgated about shortwaves
and how they travel in the atmosphere. This work is a great testament to the level
of expertise that exists in the realm of Amateur Radio, and the contributions made
by it to the science world...
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 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...
Monday the 3rd
 This quad of
electronics-related comics appeared in the March 1967 issue of Radio-Electronics
magazine. Their themes reflect the norms and issues of the era. If you have ever
had to re-string the dial cord on a radio where the path turned a few corners and
ran around three or four tuning element pulleys, then you will appreciate the comic
from page 101. My most challenging dial cord adventure was on a Realistic Patrolman-50
portable radio. It was bought on eBay, and the dial cord broke shortly after I received
it. Without a routing diagram, it took a bit of head scratching to get figure out
the correct direction for wraps around dials and pulleys. The oscilloscope display
on the page 59 comic is pretty funny...
 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.
 Here's a gimmick that never really caught
on. In the 1960's, Antenna Specialists promoted their Model M-148 Co-Ax Omni Antenna
"with
visual RF indicator." This 1966 Popular Electronics magazine ad is a prime example.
That indicator was a neon light bulb at the tip which lit up when the transmitter
was keyed on. Not only would this novel feature let you know when your transmitter
was broadcasting, but it would also "guide mobiles visually to your 10-20." OK,
maybe at night, but it certainly wouldn't have been bright enough during the day
to even see. Alas, the feature evidently didn't impress the buying public as much
as it did the designers. Maybe it had something to do with operators not wanting
to waste transmitter power for the purpose of lighting a neon bulb. Oh well, nice
try...
 "Bird, recognized as the leader in RF communications,
measurement and new technologies, has released an exclusive
Master RF Analyzer Kit. This Master RF Kit (SK-SH-KIT)
provides all the necessary equipment needed for field technicians and engineers
for installation, troubleshooting, and maintenance of coaxial cable and antenna
systems, and analysis of system performance. It provides coverage with the SiteHawk™
Cable and Antenna Analyzer, SignalHawk™ Spectrum Analyzer, including a power sensor,
calibration combo, and an assortment of adapters and cables. Bird's Master RF Kit
provides a wide frequency range..."
 Television broadcast stations were quickly
growing in number in the post-Korean War era and the FCC needed to devise a
scheme for accommodating more channels. There were only 13 channels (only 2-13
used) allocated in the VHF spectrum with 6 MHz-wide bands. Even though VHF
propagates primarily in a line-of-sight mode, reflections and earth-bounce can extend
the range fairly significantly, limiting density in closely spaced cities. The military
refused to yield any spectrum so a decision was made to add new channels (14-83,
also 6 MHz wide) in the UHF band. UHF presented its own problems with more
difficult equipment manufacturing issues and higher atmospheric attenuation. It
never really caught on because cable TV was being widely installed in metro areas
and even into suburbs by the early 1960s. Over-the-air (OTA) transmission issues
were eliminated...
 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...
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. I also
have an extensive list of
Recently Added topics.
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