Today in Science History -
When this "Four
New Sources of Power" article appeared in Radio−Electronics magazine
in 1960, most people had never heard of a fuel cell, the Seebeck effect, thermionic
effects, or magnetohydrodynamics. All had been around as features embedded in common
products in some manner, like thermionics in vacuum tubes. It is pointed out that
Sir Humphrey Davy invented the fuel cell technique in 1802, thermoelectricity by
Thomas Seebeck in 1821, thermionic effects by Thomas Edison in 1878, and magnetohydrodynamics
by Michael Faraday in 1831. Today, all four types of power sources have been integrated
into a host of products. Whereas thermionics was among the most common in 1960,
it might be the least common of the four nowadays...
This
Bulova Accuquartz wristwatch is not the first quartz-controlled wearable timepiece;
however, it was the first to be manufactured in the U.S. Interestingly, it is not
a fully electronic watch because the quartz crystal stimulates a mechanical tuning
fork which ultimately drives the hands. Bulova's first tuning-fork-driven "Accutron"
was introduced in 1960. It sported a 360 Hz tuning fork that was stimulated
by a pair of electromagnets. The story appeared in a 1972 issue of Popular Electronics
magazine. The retail price at the time (pun intended) was $395, which in 2023 money
is equivalent to $2,832 (per the BLS Inflation Calculator)! I found a couple nice
photos of the Accuquartz...
"'This partnership will build on SPL's
world-first 5G demonstration from the stratosphere in 2022,' said SPL CEO Richard
Deakin. Funded by Innovate UK, the trials will be at BT's labs at Adastral Park
and 'could offer transformational opportunities for sectors operating in remote
areas such as transport, maritime security and search and rescue,' said BT.
Stratospheric Platform's
(SPL's) antennas are designed to communicate directly with standard 3G, LTE/4G,
5G phones. The eventual aim is to create a 20 kW >3 m diameter version
for flight, with 500 individually steerable beams, each intended to be equivalent
to a cell created by traditional terrestrial masts - delivering up to 150 Mbit/s,
and covering a 140 km diameter, or 15,000 km2 land area. 'Virtually
any shape of beam coverage can be painted on the ground,' according to SPL..."
There are still many old-timers and beginning
nostalgic collectors out there who nurse heirloom and otherwise procured vacuum
tube radios - like this
Arvin Models 150TC, 151TC combination radio / phonograph - back to health (operating
condition) and/or keep them in good health. While it is possible to purchase schematics,
parts lists, and service instructions from many different models, there are still
some that have escaped the scanners of those publishers. For those kindred spirits
in search of such reference materials, I happily scan, clean up as necessary, and
post this collection (see complete list at bottom of page). I have dozens more that
will eventually be added over time, so check back later or send me an e-mail if
I have an issue (check the lists first, please) of Radio News, Radio-Craft,
etc. known to contain the information you need...
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...
Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners (hence "Triad") with
over 40 years of accumulated knowledge of what is required to design, manufacture,
market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA,
bi-directional, and frequency translating amplifiers are available, in formats including
tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology
partner than a vendor for our line-of-sight communications product line." Please
check to see how they can help your project.
All but two of these circuits in this "How's
Your E=IR? Quiz" can be analyzed by inspection, without even needing a calculator
or writing down equations, because the component, voltage, and current values given
are integer ratios that make the math easy. It appeared in a 1969 issue of Popular
Electronics magazine. You might end up with an order-of-magnitude error when
mentally calculating milli, kilo, etc., but your base number will be correct. Numbers
8 and 10 are a bit trickier. Your approach might be to rearrange the schematic to
create more recognizable series and/or parallel component configurations. For number
8, I ended up writing equations for the three circuit loops and solving the simultaneous
equations because I did not see the balanced bridge configuration at first. However,
my mesh equations yielded I25Ω = 0 mA. Be careful with number 10
to not assume...
Providing full solution service is our motto,
not just selling goods. RF & Connector Technology has persistently pursued a management
policy stressing quality assurance system and technological advancement. From your
very first contact, you will be supported by competent RF specialists; all of them
have several years of field experience in this industry allowing them to suggest
a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable
assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically,
we put priority on process inspection at each step of workflow as well as during
final inspection in order to actualize "Zero Defects."
Regular EV chargers are bad enough with
power factor and harmonics issues, but the gross
inefficiencies in power transfer with contactless charging will make matters
even worse. Imagine a world full of them! "Consumers are eager to cut the cord on
their electronics charging devices, a trend that could soon benefit drivers of electric
vehicles (EVs). HD Radio developer and licensing company Xperi is seeking to raise
awareness about a potential new threat to AM radio broadcast reception: the proposed
introduction of wireless power transfer systems for electric vehicle charging, or
WPT-EV, that use switching frequencies that generate harmonics in the lower
AM band. Xperi recently filed comments about this concern in response to a notice
of inquiry at the FCC about radio receiver performance. It hopes to raise awareness
and also believes its HD Radio technology can be of help. Interference to AM from
unintentional radiators including low-cost switching power supplies in EVs is a
concern..."
I wonder why today's editions of the ARRL's
QST magazine does not have a column dedicated to the "YL" (Young Lady, or female
in general) contingent of the amateur radio realm? Ham radio, as most - if not all
- historically male-dominated hobbies has fairly significant outreach efforts to
try attracting women into activities. My Model Aviation magazine has a
monthly column written by a lady whose enthusiasm for model airplanes equals that
of most males - and she's funny to boot! - but it is not dedicated to female modelers.
If there is a girl or woman present at a competition, she is almost guaranteed to
receive coverage in the form of a photograph and/or mention in an article. Any lack
of other-than-male participation these days can only be attributed to a lesser degree
of interest by other than males. Could there really be a difference between men
and women (in general) after all?
"Has it happened to you? When troubleshooting
an
electromagnetic interference (EMI) issue, you've tried various combinations
of components and saw the signal of interest reduced. But another frequency signal
unexpectedly raised above the limit line. Or, you introduced a chassis plane on
your printed circuit board (PCB), only to find the radiated emissions became much
worse instead of getting better. These are typical cases of 'tuning the resonances
of a circuit.' Most EMI emissions are related to structural resonances. Structural
resonances are also one of the main reasons that electromagnetic compatibility (EMC)
can be mystifying. Unknowingly, engineers often spend days and months tuning the
resonances of a circuit by adding passive elements such as inductors and capacitors.
Sometimes, they are lucky enough to finally arrive at a combination that would give
them a pass. But most of the time, solutions are hard to find. A tremendous amount
of work has been done on the subject of structural resonances. Two practical case
studies are presented to demonstrate methods to identify, locate, and fix EMI issues
that are associated with structural resonances. EMC engineering often requires problems
to be resolved..."
It's time for little levity. These
electronics-themed comics from a 1944 issue of Radio−Craft magazine
have an electronics theme, so you can claim looking at them is work-related since
you might use one for your next conference or project status presentation. Some
of the concepts are utterly foreign to contemporary readers, like user-serviceable
electronics apperati [sic] and radio sets that receive over-the-air signals with
analog information modulated on the carrier. Radio was still somewhat of a novelty
to much of the public, and "radio can do anything" memes were common in comics.
I took the liberty of colorizing them. There is a list of many more similar comics
at the bottom of the page in case you haven't seen them yet. Enjoy.
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Using modern blazing speed computers and
sophisticated programs, designing and analyzing something as complex as a
spiral conical antenna is child's play - and many school-age children actually
do it. It wouldn't surprise me if there is a phone app capable of performing such
tasks. However, back in 1960 when this article appeared in Radio−Electronics
magazine, a lot of intuition, guesswork, and trial and error on physical models
was necessary to model and parameterize the spiral conical antenna shown on the
cover. This particular antenna resonates at 14 MHz with a 1.25:1 VSWR, however
across the 7-17 MHz intended bandwidth the VSWR can be as high as 6:1. Surprisingly,
an image search for spiral conical antenna radiation patterns did not turn up much.
This paper from the International Center for Radio Astronomy Research is about the
best I could find...
Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
downconverters. Since the conception of WFT, we have introduced products that have
been purchased by a wide range of customers, from hobbyists to education facilities
to government agencies. Worldwide customers include Europe, Australia, and Asia.
Please contact Windfreak today to learn how they might help you with your current
project.
Here are the schematic and parts list for
Zenith model
5R080 and 5R086 radio/phonograph combos, from a 1947 issue of Radio News
magazine. It must have been a fairly popular set because many have been sold on
eBay; in fact, that's where I got the photos shown here. The schematic page from
the Sam's Photofact also came from an eBay listing. Note where it says that unless
otherwise noted, all resistors values are ±20%. I suppose when your phonograph
turntable uses a metal chain drive mechanism, precision isn't a huge concern. There
are still many people who restore and service these vintage radios, and often it
can be difficult or impossible to find schematics and/or tuning information; that's
why I keep a running list of all the data sheets I find to facilitate searches...
This story on the Supply Chain Connect website
caught my attention because of the photo of the huge new Digi-Key building in
Thief
River Falls, Minnesota (about as far north you can go in the USA). "Join us
as we explore the latest development in supply chain automation when we visit
Digi-Key's newly opened, 2.2 million-square-foot, PDCe in Thief River Falls,
Minnesota. After the ribbon is cut, we learn how one of the 10 largest warehouses
in the country plans to accelerate into the next decade. We sit down with Digi-Key
leadership, including Vice President, Order Fulfillment at Digi-Key, Chris Lauer,
to talk about new areas of growth and the implementation of technology that pushes
the envelope of supply chain automation. We answer questions like: What are the
challenges that come with shipping 13.4 million products to more than 857,000 customers
each year in 180 countries..."
If you are just starting out in the realm
of electronics or maybe just need a little freshening up of your basic math skills,
this rather extensive article from a 1942 issue of QST magazine is just
what you need. Author Dawkins Espy does a really nice job of laying out the basics
of algebraic operations, Ohm's law, trigonometry, and logarithms. Examples are provided
for each category. In this day of calculators doing all the hard work of calculating
logs, antilogs, and trig functions, it does even seasoned veterans at electronics
calculations a bit of good to do a quick read-through to knock off cobwebs in the
gray matter. How long has it been since you have seen tables of sine, cosine, and
tangent values and/or tables of logarithms? Not long enough, you say?
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
The
Wireless Telecom Group,
comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer
of advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
As of September 16, 2022, if I fly my radio-controlled
model airplane, helicopter, or drone even an inch off the ground anywhere in the
U.S. without having a specially designed and certified electronics device - at my
expense - broadcasting identification and position data ("Remote
ID of Unmanned Aircraft"), I can be fined and/or jailed and/or have my equipment
confiscated by the U.S. government. The stated justification is concern for safety
of property, persons, and national security. However, if a country established as
a military and economic threat to the U.S. flies a huge uncontrolled (other than
by altitude in air currents) aircraft burdened by maybe 1000 pounds of equipment,
including batteries, from coast to coast across populated areas, no action is taken.
Here is a video of the Chinese balloon finally
being shot down over the ocean after it was allowed to collect and relay data,
and even possibly release pathogens over wide areas for days (NOAA
HYSPLIT trajectory). Here's Trump impersonator
Shawn F.
with his take on the Chinese spy balloon debacle. Another victory for China!
This custom RF Cafe
electronics-themed crossword puzzle for February 5th contains words and clues
which pertain strictly to the subjects of electronics, mechanics, power distribution,
engineering, science, physics, astronomy, chemistry, etc. If you do see names of
people or places, they are directly 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.
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers"
Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's"
design has been ripped off by other people and used on their products, so please
be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per
item - Cafe Press gets the rest of your purchase price. These would make excellent
gifts for husbands, wives, kids, significant others, and for handing out at company
events or as rewards for excellent service. It's a great way to help support RF
Cafe. Thanks...
Thanks to Mr. Ferrous Steinka for submitting
this commentary on the episode of Carl & Jerry appearing in the March 1955 issue
of Popular Electronics. "Radio and television waves are reflected in the
same way as light waves. As both light and radio waves are forms of electromagnetic
waves, they are both subject to the same basic laws and principles. Visual examples
of light reflection are everywhere from specific mirrors to flat reflective surfaces
like glass, polished metal and the like. So too, radio waves can experience reflection.
Conducting media provide the optimum surfaces for reflecting radio waves. Metal
surfaces, and other conducting areas provide the best reflections, so the story
below is feasible and within the known technology at the time. The use of a highly
directional Yagi antenna would have been very important because without it the reflected
waves would have been inverted (out of phase) with the normal signals, thereby reducing
the overall received signal..."
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