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archives.
Tuesday the 7th
Ohm's Law Quiz - How's Your E=IR?
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. However, my mesh
equations yielded I25Ω = 0 mA. Be careful with number 10 to not
assume...
Please Thank RF & Connector
Technology for Their Support
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."
Wireless EV Charging Threat to AM Reception
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..."
YL News and Views
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?
EMI Issues Caused by Structural Resonances
"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..."
Electronics Themed Comics
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.
Post Your Engineer & Technician
Job Openings on RF Cafe for Free
/jobs.htm">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 /jobs.htm">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...
Thanks Once Again to everythingRF for
Long-Time Support!
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.
Monday the 6th
Spiral Conical Antennas
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...
Thanks Again for Windfreak
Technologies' Continued Support!
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.
Zenith Models 5R080 & 5R086 Schematic & PL
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...
The Future of Automation at Digi-Key
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..."
How's Your Math?
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?
Post Your Engineer & Technician
Job Openings on RF Cafe for Free
/jobs.htm">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 /jobs.htm">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...
Thanks to Wireless Telecom
Group for Their Support!
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.
Sunday the 5th
Chinese Spy Balloon Finally Shot Down
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!
Electronics Theme Crossword for February 5
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.
Get Your Custom-Designed RF Cafe
Gear!
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...
Many Thanks to KR Electronics for
Long-Time Support!
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.
Friday the 3rd
Carl & Jerry: Going Up, Up, Up
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..."
Antennas & Microchips Blur Line Between Science and
Sci-Fi
"Sophisticated antenna arrays paired with
high-frequency wireless chips act like superpowers for modern electronics, boosting
everything from sensing to security to data processing. In his lab at Princeton,
Kaushik Sengupta is working to expand those powers even further. In recent years,
Sengupta's lab has designed antenna arrays that help engineers make strides toward
peering through matter, boosting communications in canyons of skyscrapers, putting
a medical lab on a smart phone, and encrypting critical data with electromagnetic
waves instead of software. In a new article in Advanced Science, Sengupta's research
team presented a new type of antenna array based on the paper-folding art of origami.
The
shape-shifting array, designed like a folded paper box called a waterbomb..."
Voices in the Mail
This 1956 Popular Electronics magazine
article reports on the very
earliest form of voice mail - recording a message on a reel-to-reel tape deck,
placing it in an envelope, and snail mailing it to its recipient. Sure, it was slow,
but unless you were under surveillance for some suspected crime, there was just
about zero chance that some government agency was going to hear your private message.
I had forgotten about it until reading this, but I remember that back in the 1960s,
my father bought an el cheapo tape deck for our family and one for his parents,
who lived in Buffalo, New York. My parents and four sisters and I had a pretty good
time hamming it up on the tape, and looked forward to receiving a reply tape a month
or two later. "Grandpa B," as we kids called him, was a real funny guy and kept
us entertained for about 30 minutes with the reply tape. The exchange lasted for
about a year and then our machine died (I probably broke it by opening the case
and screwing with it) and then it was back to the long distance phone calls once
or twice a year...
Anatech Electronics
Intros 3 Filter Models
Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. Three new
filter surface mount, low loss ceramic bandpass filter models have been introduced
- a 2410 MHz WiFi cavity bandpass filter with a 3 dB bandwidth of
22 MHz, a 4885 MHz cavity bandpass filter with a 50 MHz bandwidth,
and a 5630 MHz WiFi cavity filter with a bandwidth of 20 MHz. 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...
1953 Radio Shack Advertisement
Against all odds,
Radio Shack
is still in operation today (barely). They still sell a fairly broad selection of
discrete components for circuit designers and for repair and modifications. Radio
Shack is and has been for a couple decades the only hometown source for parts where
you can walk in off the street to get what you need, rather than order it online.
Even items like a dual-gang stereo volume control potentiometer, a 2-layer, 6-position
rotary switch, and a DPDT PCB-mountable relay can be had. There are nowhere near
as many as there were a few years ago before all the turmoil began, but Radio Shack
is still there in a pinch. This full-page Radio Shack advertisement appeared in
the November 1953 edition of QST magazine, which was during the heyday
of electronics DIY activity. I've written in the past of visiting the local Annapolis,
Maryland, Radio Shack store with a bagful of vacuum tubes from our television set
needing testing on their testing machine. There was also a Lafayette Radio Electronics
store...
RF Cascade Workbook
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...
Many Thanks to ISOTEC for Continued Support!
Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
Thursday the 2nd
Introduction to Ultrasonics
This "Introduction
to Ultrasonics" article from a 1960 issue of Radio−Electronics magazine
does not necessarily directly apply to RF and microwaves, but there are similarities
in the circuitry and theory of generation and propagation. I was surprised to learn
that ultrasonics even back then went into the low GHz realm. Any mechanical vibrations
about about 20 kHz are regarded as ultrasonic. Ultrasonics can preform some
of the functions of x-rays in material inspection, without the danger of ionizing
radiation and extremely high voltages required to generate the rays. While working
in the 1980's as an electronics technician at the Westinghouse Oceanic Division
in Annapolis, Maryland, I often used an ultrasonic cleaner like the one shown here
for removing flux from printed circuit board assemblies (PCA's), cable connectors,
and other objects. The heated methyl-based bath solution produced a PCA with shiny
solder joint totally devoid of flux residue. We were still using 60/40, Sn/Pb rosin
core solder back then. We built sonar systems and components for the U.S. Navy,
including transducer-equipped torpedo nose cones, sonar transducer arrays for ship
hulls, and towed sonar systems...
Many Thanks to Exodus
Advanced Communications for Their Support
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.
THz Quantum Magnetic Switch at RT
"A class of nonvolatile memory devices,
called MRAM, based on quantum magnetic materials, can offer a thousandfold performance
beyond current state-of-the-art memory devices. The materials known as
antiferromagnets were previously demonstrated to store stable memory states,
but were difficult to read from. This new study, now published in Nature, paves
an efficient way for reading the memory states, with the potential to do so incredibly
quickly too. You can probably blink about four times a second. You could say this
frequency of blinking is 4 hertz (cycles per second). Imagine trying to blink 1
billion times a second, or at 1 gigahertz, it would be physically impossible for
a human. But this is the current order of magnitude in which contemporary high-end
digital devices, such as magnetic memory, switch their states as operations are
performed. And many people wish to push the boundary a thousand times further, into
the regime of a trillion times a second, or terahertz. The barrier for realizing
faster memory devices may be the materials used..."
Now! Use Gift Cards for Payment!
Since Elon
Musk purchased Twitter and began exposing the grotesque level of bias and suppression
of free speech perpetrated by social medial platforms, some people have written
to say they no longer want to use PayPal when purchasing
RF Cafe products.
I have been agreeing to send the software immediately with a promise of payment
via snail mail. On a whim, I checked to see whether Gift Cards
can be sent via e-mail, and indeed they can. So, if you want an alternative to PayPal,
I have posted links directly to Walmart, Lowe's, Home Depot, and Sam's Club, where
the majority of my purchases are made. Of course you are also encouraged to send
donations via Gift Cards. Thank you.
Radar on the Great Lakes
An article title with both "radar"
and "Great Lakes" (I lived a mile from Lake Erie) in the title is sure to catch
my attention, as did this. Author Norman Schorr reports on the state of the art
of radar equipment and usage for the purpose of maritime navigation. Research and
development, along with an ample surplus of components left over from World War II
facilitated a rapid adaptation of radar to many venues. Included among its applications
were airway and waterway navigation, rocket trajectory tracking, security systems,
speed measurement, weather observation, and aerial mapping. It is easy to take for
granted the capabilities of radar today with having the accumulated knowledge of
more than half a century on our side, but pioneers in the field had to think everything
up anew. I have to admit to being familiar with what a "Pliotron" was prior to reading
this article (it is Irving Langmuir's high frequency version of the Audion vacuum
tube)...
Keep Temperature and Humidity
Under Control
Axiom Test Equipment, an electronic test
equipment rental and sales company, has published a new blog post entitled "Keep
Temperature and Humidity Under Control" that goes over how to select a chamber
based on key specifications like size, temperature ranges and humidity. Temperature
and humidity testing provide insights into whether a product or device under test
(DUT) will fail or even meet required levels of performance when simulated and stimulated
over extreme ranges of temperature and relative humidity (RH). Being able to control
temperature and humidity provides great benefits and flexibility when evaluating
the reliability of a new design or when ensuring that a product can withstand challenging
operating conditions and provide the performance expected over a long operating
lifetime. Requirements for a temperature or temperature/humidity chamber are typical
determined by the DUT or type of DUT, such as according to its size, application,
and operating environment. Learn more about the most important equipment you will
need when testing temperature & humidity...
Horizontal Hamming
Here is a humorous story from a 1951 issue
of QST magazine - probably not too far from being true - about a Ham operator
(emphasis on "operator") who parlayed a short spat of poor health into an opportunity
to get in a little
rag-chewing
time. The whole scenario turned out so well that he pondered afterward whether
he could indulge in a bit of malingering for a repeat opportunity. So did some of
the contacts he told about it while laid up. The tale didn't appear in an April
edition, so it probably is on the up-and-up...
Promote Your Company on RF Cafe
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 16,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
Many Thanks to LadyBug Technologies
for Their Continued Support!
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Wednesday the 1st
Bendix Aviation Corporation
Bendix Corporation was begun in 1914 by
Mr. Vincent Bendix, eventually manufacturing brakes, starters, carburetors,
and other components for automobiles, trains, and airplanes. During World War II,
Bendix was a major supplier of critical components, including radio transmitters
and receivers and avionic instruments. As with many - probably most - big corporations,
advertisements were run in many magazines in order to make sure the public knew
the part their companies were playing in the effort to defeat Communism, Nazism,
Socialism, and all the other "isms" worldwide seeking to subdue and destroy freedom.
Bendix branched out into many areas of development and production with computers,
mine detectors, inertial guidance platforms (for Saturn V and other man-carrying
rockets), televisions, phonographs, kitchen appliances, and much more. I don't know
if it is still the case, but back in the 1970's when I did a lot of work on my 1969
Camaro SS, the term "bendix" was a generic reference to the solenoid-actuated
spur gear that coupled the electric starter to the big starter gear connected to
the engine crankshaft...
Boston Dynamics' Atlas Automaton - Spooky
Anyone involved in technology
for the past decade or more is aware of the progress
Boston Dynamics has made with
their automatons. Early models were tethered in order to supply the amount of electrical
energy required to operate. The newest models are completely self-contained and
move unconstrained. If you haven't already seen it, you need to watch this video
of "Atlas" as he (yep,
Atlas was a male Greek
god; maybe they need an "Otrera"
model for equality) performs amazing acts of cognition and physical dexterity. Advances
in intelligent humanoid robotics is advancing a a fairly good rate, but if you want
it to really surge we need automatons released into the domestic toy and entertainment
markets. If the history of drones is any predictor of the future, doing so would
greatly increase research and development with a resulting feedback into commercial
and military realms.
Thanks to PCB Directory for Continued
Support!
The leading website for the PCB industry.
PCB Directory is the largest directory of
Printed Circuit Board (PCB)
Manufacturers, Assembly houses, and Design Services on the Internet. We have listed
the leading printed circuit board manufacturers around the world and made them searchable
by their capabilities - Number of laminates used, Board thicknesses supported, Number
of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
Adson Radio & Electronics Co. Advertisement
Here's another advertisement that you probably
wouldn't see in a contemporary RF / microwave engineering magazine, like this one
in the 1949 issue of Radio & Television News. For that matter you probably
wouldn't see it on a contemporary RF / microwave engineering website ... except
on RF Cafe where political correctness finds no sanctuary.
Adson Radio & Electronics, an electronic components distributor, was located
on Fulton Street in New York City, just a block from the 911 Memorial. The original
building might well have been destroyed when "some people did something" (Saudi
Arabians flew two commercial jetliners into the World Trade Center towers) in 2001...
SynthHD 10 MHz-15 GHz Dual Channel
Synth Shipping
Windfreak Technologies is glad to announce
that their very popular
SynthHD, dual channel RF/microwave synthesizer is back in stock and shipping
within 3 days of ordering. The global parts shortage made a key component hard to
procure for a short while, but a dependable source has been secured. The SynthHD
covers a frequency range of 10 MHz to 15 GHz in 0.1 Hz steps, with
an output power of −50 dBm to +20 dBm in 0.01 dB steps. Channels
are totally independent with relative phase adjustment from 0 to 360° in 0.01°
steps. This allows its use in antenna beam steering applications or quadrature signal
generation commonly used in image reject frequency conversion. SynthHD is useful
in R&D and production applications. LabVIEW source code included. Please contact
Windfreak today!
A Crystal That Amplifies
Messrs. Brattain, Shockley, and Bardeen,
are credited with inventing the first working transistor per their announcement
in December of 1947. This article provides what was for many people an introduction
to the operational specifics of transistors. Although its crude point contact (aka
"cat's
whisker") emitter and collector arrangement against the doped germanium base
element was still in a configuration that did not yet represent a significant challenge
to the domain of vacuum tubes, people of vision recognized its superior potential.
As with most technologies, progress occurred quickly and within a year the first
commercial transistor was on the market. C.E. Atkins, a frequent author in Radio &
Television News magazine, related this story of his own attempts to develop
a transistor and offers the opinion that transistor might indeed someday replace
tubes as amplifiers, oscillators, and frequency converters...
RF Cascade Workbook
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...
Thanks to TotalTemp Technologies
for Continued Support!
TotalTemp Technologies has more than 40
years of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
recirculating & circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
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.
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 /jobs.htm">job openings. HR department employees and/or managers of hiring
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Exodus Advanced Communications
LadyBug Technologies
Bendix Corporation
