Today in Science History -
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...
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
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
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
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.
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..."
"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.
shape-shifting array, designed like a folded paper box called a waterbomb..."
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 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...
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 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...
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.
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...
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.
"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..."
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.
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
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...
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...
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...