Today in Science History -
Try finding the equation for
phase angle error due to VSWR mismatch, and you
will likely fail. Extensive keyword searches for related terms will turn up
websites that present the formula for amplitude error due to VSWR mismatch, but
not for phase angle error due to VSWR mismatch. If you are fortunate enough to
find the equation, you almost certainly will not be given the derivation. The
actual equation, εθmax = |Γ1 | • |Γ2|, is so simple that it seems unbelievable,
but here its validity is demonstrated. Well, the search is over thanks to Haris
Tabakovic, who was kind enough to provide this excellent derivation for the
benefit of RF Cafe visitors...
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on many types of key searches, both for text and images. New content is added on
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on LinkedIn. If you need your company news to be seen, RF Cafe is the place
Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic
instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC
initially developed custom pulse generators. We became known for meeting the most
stringent requirements for high precision and stability, and for producing instruments
of unsurpassed reliability and performance. We continue to maintain a leadership
position as a developer of custom pulse, signal, light, and function generators.
Our designs incorporate the latest innovations in software and hardware engineering,
surface mount production, and automated testing procedures.
Charts and nomographs are not nearly as
useful or necessary today for the design and troubleshooting of electronics due
to the ready availability of calculators in the form of computers, tablets, and
smartphones. Determining parallel and series resistance, capacitance, and inductance,
reactance, power dissipation, resonant frequency, voltage dividers, etc., can easily
be done with the push of a few buttons (or virtual touch-sensitive screen buttons).
Not only is it not necessary to know the equations behind the calculations, but
you don't even need the know how to enter mathematical operations into a calculator.
A lot of old-schoolers say the availability of newfangled electronic gizmos contributes
to the dumbing down of technicians and engineers. If you can't use a slide rule,
then you don't truly understand the science. I wonder if their attitudes were the
same when special-purpose cardboard slide calculators and even design charts like
this one and nomographs were published?
The introduction of low cost, small-footprint
ceramic filters were unquestionably a boon to efforts at reduction in end-product
package size and manufacturing cost. Very good Q and selectivity, no tuning required,
and good temperature stability made them perfect for use as IF filters in broadcast
radio receivers, at 10.7 MHz (FM) and 455 kHz (AM). They became available
for commercial use around 1960. This publically available paper published in 2000
from the IEEE provides some historical perspective to ceramic filters: The History
of Ceramic Filters, by Satoru Fujishima. The Clevite Corporation, for which this
Electronics World author, Reg Zimmerman worked, is mentioned in the IEEE paper,
as is Murata, for being pioneers in the ceramic filter field...
"Inside today's computers, phones, and other
mobile devices, more and more sensors, processors, and other electronics are fighting
for space. Taking up a big part of this valuable real estate are the cameras - just
about every gadget needs a camera, or two, three, or more. And the most space-consuming
part of the camera is the lens. The lenses in our mobile devices typically collect
and direct incoming light by refraction, using a curve in a transparent material,
usually plastic, to bend the rays. So these lenses can't shrink much more than they
already have: To make a camera small, the lens must have a short focal length; but
the shorter the focal length, the greater the curvature and therefore the thickness
at the center. These highly curved lenses also suffer from all sorts of aberrations,
so camera-module manufacturers use multiple lenses to compensate, adding to the
camera's bulk. With today's lenses, the size of the camera and image quality are
pulling in different directions. The only way to make lenses smaller and better
is to replace refractive
lenses with a different technology..."
Recognizing that many people were reluctant
to approach the theoretical aspect of electronics as it applied to circuit design
and analysis, QST (the American Radio Relay League's monthly publication)
equations and explanations in many of their project building articles. Occasionally,
an article would be published that dealt specifically with how to use simple mathematics.
In this case, the June 1944 edition, we have the second installation of at least
a four-part tutorial that covers resistance and reactance, amplifier biasing (tubes
since the Shockley-Bardeen-Brattain trio hadn't invented the transistor yet) oscillators,
feedback circuits, etc. I do not have Part I from the May 1944 edition or Part IV
from the August 1944 edition, but if you want to send me those editions, I'll be
glad to scan and post them...
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...
Amplifier Solutions Corporation (ASC) is
a manufacturer of amplifiers for commercial & military markets. ASC designs
and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers
for low, medium and high power applications using Gallium Nitride (GaN), Gallium
Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs
operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film
designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility
in the town of Telford, PA. We offer excellent customer support and take pride in
the ability to quickly react to evolving system design requirements.
This week's crossword puzzle for June 4th
electronics theme. This being the fourth day of the month, many of the words
begin and/or end with the letter "D." Besides that, we're only two days away from
"D-Day." All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger,
and have only words and clues related to RF, microwave, and mm-wave engineering,
optics, mathematics, chemistry, physics, and other technical subjects. As always,
this crossword contains no names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort unless it/he/she is related to this
puzzle's technology theme (e.g., Reginald Denny, Hedy Lamarr, or the Tunguska event
in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
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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.
Back in the early 1990s I had my first need
as a product design engineer to
select a fuse type; it was for protecting a downconverter chassis. Having
already worked in the electronics and electrical equipment installation and maintenance
field for twenty years, I have had to replace many fuses of many different types
in many types of assemblies ranging from AC motor controls to microprocessor boards.
Slo−Blo, Fast−Blo, Standard−Blo, high voltage and low voltage, high current and
low current, glass bodied, plastic bodied, and even metal explosion-proof bodied
fuses were in the realm my experience. However, some other engineer had already
decided what the appropriate fuse was for the application. I assume each instance
had been determined from a selection process based on knowledge of both the device
to be protected and the characteristics of the fuses. Not just any fuse will do
the job. Sometimes you get lucky and the one used will work so long as the current
and voltage ratings are within the normal operational range of the product being
protected, but if that was generally the case, there wouldn't be such a large variety
of fuse types, n'est−ce pas? This "Fuses Are Not for Confusion" article from a 1960
issue of Popular Electronics magazine is a great primer on the art of fuse
Regardless of your position on the appropriateness
of actions taken by world governments and private entities regarding the COVID 19
debacle, if you truly do "believe the science" as we were all admonished to do,
then you are obligated to avail yourself of validated, relevant data. Those of us
who had researched the issue and arrived at our own conclusions early on were routinely
condemned and demonized for daring to buck the official narrative. By all accounts
we should have expired long ago from the virus while the believers enjoy practically
eternal life from being vaxxed ... and revaxxed ... and revaxxed... Seems the opposite
has happened. Sadly, many people still have not exposed themselves to information
from other than the perpetrators of the deed. This presentation by
Dr. David Martin, at the International
COVID Summit | 2023 European Parliament will shock you (~15 minutes) regardless
of your beliefs. The level of deception and lying has been epic - with catastrophic
results. If you still enthusiastically support the official narrative, fear not,
your heroes will not face any penalty. How many weeks will be needed next time to
"flatten the curve?"
I was first introduced to the
Simpson 260 volt-ohmmeter (VOM) in the radar shop where I was assigned in the
USAF. Here is the modern version of that classic, the Simpson 260-8 VOM; it looks
a lot like the original. Here is an advertisement that I scanned out of my copy
of the July 1944 QST magazine. It highlights the precision to which its
meter movement pivots are manufactured. "While Simpson Electric Company, chartered
in 1934, is a firm with a distinguished past, it is just as importantly an organization
with a dynamic present and a definite future." There is an entire website dedicated
to the history of the Simpson 260. The famous 260 Volt-Ohm-Milliammeter put Simpson
on the map and cemented a reputation for quality that still defines Simpson in the
marketplace today." You can still buy a brand new Simpson 260 (-8) from Amazon -
and it isn't cheap - or grab a vintage Simpson Model 260 on eBay for under $100...
Werbel Microwave, a designer and manufacturer
of RF and microwave power couplers, dividers, terminations, and DAS equipment, introduces
the Model D−2065−N from Werbel Microwave is a
2−way power splitter covering the continuous bandwidth of 500 MHz to 6 GHz.
The product features low insertion loss of 0.9 dB, high isolation of 22 dB
and excellent return loss performance of 19 dB. Tight phase and amplitude matching
between outputs. Aluminum body with stainless steel N(F) connectors. Small size,
only 0.75 in thick, allows for dense stacking in tight spaces. Werbel Microwave's
catalog of directional couplers and power splitters / combiners are high performance
at an affordable price point. Our original design. Click here for the C-9001-8.5
spec sheet. About Werbel Microwave In-House Manufacturing Capability Werbel Microwave
started in 2014 humbly working out of a one-car garage. Since then we have grown
to occupy a 1300 square foot office and shipped over 10,000 products to date...
Most of these matches of the devices and
its inventor are pretty easy for people who have been around electronics for any
length of time (well, not if the length of time is only a day or two), but there
are a couple that just might stump you. This "Electronics
Inventors Quiz" appeared in the November 1963 issue of Popular Electronics
magazine, so you won't be challenged with knowing the inventors of the LCD or MEMS
devices, but neither will you have to know who came up with the abacus or the Archimedes
screw :-). I managed to score 100%, but that was admittedly partly luck in deciding
between two men for items "B" and "C." The other eight should be a piece of cake
for most RF Cafe visitors...
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
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. The file
format is XML so everything plays nicely with Visio 2013 and later...
Alliance Test Equipment sells
used / refurbished
test equipment and offers short- and long-term rentals. They also offer repair,
maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP,
Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization
with ability to source hard to find equipment through our network of suppliers.
Alliance Test will purchase your excess test equipment in large or small lots. Blog
posts offer advice on application and use of a wide range of test equipment. Please
visit Allied Test Equipment today to see how they can help your project.
The decade of the 1960s was probably the
heyday of television. Household incomes had been steadily rising since the end of
World War II while inflation was relatively low. The Korean War was over and
until around 1965 the country was not on a serious war footing. Game shows, soap
operas, shows depicting non-dysfunctional families, variety show formats, non-woke
cartoons, movies, and newscasts that didn't insult half the country with biased
coverage fed the country's appetite for wholesome, useful entertainment. Once violent
race riots and hippie anti-establishment protests became a major threat to safety
and civic deportment, people monitored radio and television to keep abreast of events.
In accord with rapidly improving television sets were advances in
antenna technology. Viewers wanted the best possible picture and audio, and
were willing to pay dearly for it. Through around the end of the 20th century, after
which cable dominated as a transmission medium, over-the-air broadcasts in increasingly
crowded RF environments made higher performance antennas even more necessary...
"Many situations arise in which an antenna
needs to dynamically reconfigure its center frequency or beam pattern. In some cases,
this can be done with a steerable, multi-element antenna array, but it's often not
a viable solution for various reasons. As an alternative, a team of electrical engineers
in the Penn State College of Engineering devised an innovative design for a reconfigurable
patch antenna dubbed a
reconfigurable compliant mechanism antenna (rCMA). The antenna, which leverages
the inherent elastic properties of selected material to create a desired motion
through controlled deformation, is designed to operate up to 10 GHz. These
compliant mechanisms can be made as a planar structure from a single material yet
still achieve multi-axis motion. Further, they can be designed as a full structure
with minimal or even no assembly, require no lubrication, and their reliability
is high, as it's based on the elastic properties of the material..."
Amateur radio station operators seemed to
always be amongst the first to lose their rights in time of war. Governmental power
brokers - from unelected local bureaucrats on up to presidents - love to demonstrate
their influence over citizens when the opportunity arises. The
Radio Act of 1912 revoked the rights of amateur radio stations to operate, and
in some cases authorized the confiscation of radio equipment for use by the government.
Permission was not restored until 1919, after World War I. Amateurs took it
on the chin again in World War II with revocation of licenses. In this 1917
article in The Electrical Experimenter magazine publisher Hugo Gernsback
makes the case for permitting "our red-blooded boys be trusted to assist our officials
in running down spies." "...we realize how absurd it is to close all privately owned
radio stations during the war," says he. It fell on deaf ears, as usual. As the
now mayor of Chicago once famously said, "You never want a serious crisis to go
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 models have been introduced - a 1176 MHz / 1575 MHz ceramic duplexer with
an 18 MHz minimum bandwidth, a 1616 - 1626.5 MHz cavity bandpass filter with
TNC female connectors, and a 4900 MHz bandpass filter with N-type male / N-type
female connectors. 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...
International Geophysical Year (IGY) was an international scientific project
that took place from July 1, 1957, to December 31, 1958. It was a collaborative
effort involving scientists from around the world to conduct research in various
fields of geophysics. The IGY was organized in response to a proposal by the International
Council of Scientific Unions (ICSU) to promote international cooperation in the
study of the Earth and its environment. The project aimed to advance our understanding
of Earth's physical properties, including its atmosphere, oceans, and solid Earth.
During the IGY, scientists conducted research in a wide range of disciplines, such
as meteorology, seismology, glaciology, oceanography, and solar physics. They used
cutting-edge technologies and established numerous research stations across the
globe to gather data. One of the most significant achievements of the IGY was the
International Geophysical Year Antarctic Program. Several countries established
research bases in Antarctica, leading to significant discoveries about the continent's
geology, weather patterns, and wildlife...
After reading the first paragraph of this
"Mac's Service Shop" technodrama entitled, "Technician
of Consulting Engineer?," I expected to be told a story about the seemingly
excited customer exiting the shop as he returned from lunch. Had the man made an
unreasonable demand on Mac McGregor, the proprietor, and was rebuffed appropriately?
It never materialized. In the second paragraph underling technician Barney mentions
having seen two men exiting the shop on his way in, not just one. At that point
I'm wondering what sort of melee had just occurred. As it turned out, my interpretation
of the event was totally incorrect. While explaining the happenings to Barney, he
imparts, as he is want to do, a couple clever bits of technical information in the
process. This appeared in the October 1960 issue of Electronics World magazine...
If only eBay had been around at the end
of World War II, this surplus equipment would have dominated the electronics
and electromechanical gizmo categories. Electronics magazines of the post-WWII era
were filled for years with advertisements like this one from G & G
Radio Supply Company in a 1953 issue of Radio & Television News magazine.
That B-29 bomb sight, like the one used on the Enola Gay, could be purchased brand
new for a scant $295, which even in equivalent 2018 dollars of $3,3142,758 (per
the BLS), is a steal. This is not the famous Norden bombsight, but it's still a
sweet collector's item, which is available on eBay today if you would like to own
one. Already have a B-29 bombsight? How about a complete IFF (Identification Friend
secondary radar system? For a mere $350 you could have owned a complete rack
of RC−188−A equipment, including the rack and chassis, a 450 W power supply,
a 157-185 MHz transceiver (not in the Ham bands), a 5" CRT display, and a slew
of vacuum tubes...