 Friday the 24th
Thursday the 23rd
Wednesday the 22nd
Tuesday the 21st
Monday the 20th
 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. I also re-broadcast homepage items
on LinkedIn. If you need your company news to be seen, RF Cafe is the place
to be.
 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.
Sunday the 19th
 This
Electronic Oscillator Theme crossword puzzle for September 19th, 2021, contains
only words and clues related to engineering, mathematics, chemistry, physics, and
other technical words. 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., Hedy Lamarr or the
Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
Friday the 17th
 Even in this current age of ubiquitous computers
and cellphones (also computers), there is still ample reason to consider using
nomographs for presenting data and providing a hand calculation or conversion
resource. In days prior, nomographs were an indispensible tool for both design and
troubleshooting circuits. A huge number of nomographs can be found here on RF Cafe
as they appeared in vintage magazine articles. This 1946 issue of Radio-Craft presents
the first of a two-part tutorial on creating nomographs for any purpose, and uses
current, voltage, and resistance as an example. Their utility is not limited to
electrical and electronic topics, as many have been created for plumbing, hydraulics,
mechanics, chemistry, finance, aerodynamics, pneumatics, lighting, acoustics, and
I've even seen one...
 Is it just me or does this seem like a moot
/ obvious arguement? "For anyone looking for an end-of-the-summer mind bender, this
might be one to consider.
Where does the terahertz (THz) spectrum range start? The subject came up during
a symposium last year, and it was covered here. Some researchers figure it starts
at 100 GHz. Others say it's 300 GHz. Suffice it to say, the debate is alive and
well - depending on who you talk to. Why should we care? For one, it helps to know
what’s what when it comes to spectrum, the idea being there's a finite amount in
the lower bands. Some day, somebody will come knocking for even more spectrum, and
these very high frequency ranges will come in handy when there's nowhere else to
go. For another, it's part of the grand plan for 6G, and even though it's early
days in a lot of ways for 5G..."
 Navy electrical equipment is designed and
installed with every possible provision for the safety of the men who use it and
service it. But this does not completely
prevent injury to you and your shipmates or damage to equipment. Safety also
depends on the Electrician's training. To insure safety while standing watch or
working on a circuit, he must always work safely and observe safety precautions.
Men have been burned, electrocuted, or maimed for life because they became careless
in their work or failed to observe safety precautions. You were selected to be an
Electrician's Mate because of your intelligence, so use your brain to prevent accidents.
Injury and damage can be avoided by staying alert, exercising intelligence...
 Teledyne Relays today announced availability
of a significantly expanded line of
50+
GHz coax switches, adding transfer switching, terminated, and normally-open
models to its product line-up. These join the CCR-50U SPDT DC-53 GHz failsafe/ latching
relay and CCR-39 SPnT DC-52 GHz latching coax relays that already enjoy wide acceptance.
In addition to excellent RF performance, the family offers the widest operational
temperature range (-55 to +85 °C), lowest weight and amongst the longest life (up
to 5 million actuator cycles) of any 50 GHz switches available today...
 In this August 1963 adventure from Popular
Electronics magazine, teenage techno-investigators Carl Anderson and Jerry Bishop
use their home-brew sonar device to help the local sheriff nab a couple bank robbers.
The "Hydro Probe" mentioned in the article was a real product manufactured by the
Raymond Development Company of Watertown, Massachusetts (no longer in business).
By this time the duo were students pursuing electrical engineering degrees at Parvoo
University (a play on Perdue University, located in the boys' home state of Indiana).
Enjoy.
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. I also re-broadcast homepage items
on LinkedIn. If you need your company news to be seen, RF Cafe is the place
to be.
 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.
Thursday the 16th
 Remember the early 1990s Teen Talk Barbie
where one of her phrases, "Math
class is tough!," caused a big kerfuffle because it ostensibly stereotyped girls
as being afraid of math? Maybe if Talking GI Joe (this 1967 version is the
one I had as a kid) also uttered a math phobia statement all would have been fine.
The truth is that a large portion of both girls and boys (and men and women) of
all ages break out in a cold sweat whenever the subject of math arises in print
or in a conversation. The ARRL goes to great lengths to help ease the math anxiety
of radio operators who are studying for a license exam. In this multi-part 1946
Radio−Craft magazine article, the authors attempt to assuage some of the
reluctance of readers to apply mathematics to their electronics hobby endeavors...
 "Seeking a route to high-performance power
semiconductors, scientists in Japan have bonded
gallium nitride to a diamond substrate – the latter an insulator whose thermal
conductivity is many times that of copper or silver. 'The researchers succeed in
the direct bonding of diamond and GaN at room temperature, and demonstrate that
the bond can withstand heat treatments of 1,000°C, making it ideal for the high
temperature fabrication process of GaN-based devices,' according to Osaka City University,
home of the project. Unsurprisingly, attempts have already been made create a GaN-on-diamond,
using some form of transition or adhesion layer..."
 Canadian website visitor Richard F.
sent me this photo of his "Log
Polar Plane" acetate stencil, circa 1958. As a collector of vintage of science
/ technical paraphernalia, he ran across this as part of one of his acquisitions.
"Computing Aids" is printed on it. I had never heard of the log polar plane, but
according to the Wikipedia entry, "In mathematics, log-polar coordinates (or logarithmic
polar coordinates) is a coordinate system in two dimensions, where a point is identified
by two numbers, one for the logarithm of the distance to a certain point, and one
for an angle. Log-polar coordinates are closely connected to polar coordinates,
which are usually used to describe domains in the plane with some sort of rotational
symmetry. In areas like harmonic and complex analysis, the log-polar coordinates
are more canonical than polar coordinates." The David Young, on the University of
Edinburgh website, explains, "Log-polar sampling is a spatially-variant image representation..."
 It was a little difficult to make out the
shape within the
crossword puzzle grid from this December 1960 issue of Popular Electronics
magazine, so I got out my blue Crayon and filled in the hashed squares. It appears
to be a transistor schematic symbol. Unlike the weekly RF Cafe crossword puzzles,
not all of the clues and words are specifically related to science and engineering,
but a large percentage of them are. Admittedly, I have the advantage of a software
program to help place the words within the grid. Margaret LeFevre did not. Doing
it by hand is a lot more work. I can't imagine how the people who created the
New York Times' Sunday-size puzzles were able to do it without computer
assistance!
 Innovative Power Products (IPP) has over
30 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Please take a couple minutes
to visit their website and see how IPP can help you today.
Wednesday the 15th
 "Why the Tube Shortage" was not a question
being asked by Radio−Craft magazine editor Hugo Gernsback, it was an explanation.
It is similar to the present day situation with the "Global Chip Shortage" in all
the headlines being blamed on the Wuhan Flu plandemic (sic) causing a worker shortage.
It has affected everything from the production of smart watches to kitchen appliances
to cars and trucks. In 1946, however, the cause of the
vacuum
tube shortage was a multi-faceted ordeal according to investigative work by
Mr. Gernsback. Service shops were accusing tube manufacturers of favoring radio
production companies while radio production companies accused the tube manufacturers
of favoring service shops. The truth, ostensibly, was that the federal government
still laid claims to a large portion of tube manufacturing for post-war defense
needs, and at the same time labor strikes were crippling production lines...
 Berkeley 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.
 "Visible light has been used to communicate
for centuries. Lanterns on ships and Morse code flashes allowed information to be
conveyed at a distance. But now there's a better way to use light to communicate
over even further distances and with far more accuracy: lasers. Launching in 2021,
NASA's
Laser Communications Relay Demonstration (LCRD) is going to geostationary orbit,
where it will communicate with the ground at gigabit speeds. It's the agency's latest
step to get more data from space per downlink. Currently, most NASA missions use
radio frequency communications to send data to and from spacecraft. Radio waves
have been used in space communications since the beginning of space exploration
and have a proven track record of success. However, as space missions generate and
collect more data, the need for enhanced communications capabilities becomes paramount..."
 ConductRF offers many lines of Lab &
Production RF Test solutions for DC to 18 GHz.
TEA80
series TESTeCON and TESTeLINK RF Cable lines feature standard connector choices
include straight male, female, and bulkhead, and right angle male. Standard interfaces
include type-N, TNC, SMA, 3.5 mm, and 2.92 mm. Phase stable testing ±4°
to 18 GHz, amplitude stable to ±0.2 dB to 18 GHz, max power 170 W
@ 18 GHz, flex life over 10,000 cycles, cable loss <0.330 dB/ft @ 18 GHz,
VSWR <1.30:1 (typical < 1.20:1). These cables can be purchased directly from
Digi-Key. ConductRF VNA series provides customers with reliable ruggedized solutions
for lab and production vector network analyzer testing. With options for 18, 26.5,
40, 50 & 70 GHz...
 Narrow-band frequency modulation (NFM) was
a relatively new technology in 1947, having been advanced significantly during World
War II. Amateur radio operators were just getting their gear back on the air
after having been prohibited from transmitting for the duration of the war (see
"War Comes," January 1942 QST). Few were probably thinking about adopting
and exploiting new modulation techniques, but for those who were and recognized
FM as the path to the future of radio, QST published this fairly comprehensive
treatment of both frequency modulation (FM) and phase modulation (PM). Mathematically,
FM is the time derivative of PM. Both modulation schemes vary the carrier frequency
in some proportion to the baseband signal. Author Byron Goodman provides some insight
into the techniques...
 Since 2003, Bittele Electronics has consistently
provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly
services. It specializes in board level turnkey
PCB assembly
for design engineers needing low volume or prototype multi-layer printed circuit
boards. Free Passive Components: Bittele
Electronics is taking one further step in its commitment of offering the best service
to clients of its PCB assembly business. Bittele is now offering common passive
components to its clients FREE of Charge.
|
 James Kilton Clapp in 1948 first published
details on an oscillator that used positive feedback obtained from an LC (capacitive &
inductive) voltage divider to initiate and sustain oscillations. Thus was born the
now familiar Clapp oscillator. It had an advantage over both the Colpitts and Hartley
oscillators because the feedback, not being dependent on a simple capacitive or
inductive voltage division, respectively, made it more reliable as a variable frequency
oscillator (VFO). This article does a nice job of explaining the operation of the
Clapp oscillator. Just as the Colpitts and Hartley oscillators handily provide an
easy mnemonic for being based on voltage dividers of capacitance with the Colpitts
oscillator and inductance (Henries) with the Hartley oscillator, the Clapp oscillator...
 Copper Mountain Technologies is pleased to
announce that
Online Help manuals are now available for S2VNA and PXIe software by selecting
the Online Help buttons. These online manuals are easy to navigate and have been
designed to deliver an enhanced user experience. Online Help manuals for additional
software versions are in development. The existing operating manuals and documentation
for all other versions of software are available for download. If you prefer to
use a PDF manual for S2VNA or PXIe models, it is also available to download by clicking
the "Download Documentation" button...
 Admittedly, the concept is not original,
but the design and slogans are. So as to not step on anyone's trademark for the
periodic table of elements format, I borrowed from one from the NIST website, which
being owned by we the taxpayers (and there are fewer of us all the time), is open
source. My inspiration for the RfCaFe
scheme was from the Human
Element (Hu) ads put out by Dow Chemical years ago. They chose element #8 (oxygen),
but #6 (carbon) seems more apt to me. I thought it was clever and intended to make
one for RF Cafe, and just now got around to it. It will appear on
September 26th and
December 6th as the website logo.
 Having never been a sports aficionado, I
have not spent much money or time at baseball, football, or soccer fields, hockey
rinks, bowling alleys, curling sheets, or basketball courts. When an air show comes
to town, however, I'm there. I'll stand in line for 45 minutes to tour the inside
of a DC-3, B-25, B-17, PBY-5, or just about anything that will admit me. What is
particularly enjoyable is being able to inspect the
radio equipment racks and bays. The sight and smell (I consider it an aroma)
of the old UHF and VHF sets, recording equipment, power supplies, generators, synchros,
and the associated wiring and connectors is something I never tire of experiencing.
I always imagine the men who operated and maintained everything doing their assigned
duties to keep those wonderful machines flying. Maybe you know of what I write.
This article provides a nice overview of the state of the art for airborne electronics
in the post WWII era.Dig the Zenith console radio...
 This is really clever. Appearing in the March
1955 edition of Popular Electronics magazine, "The
Electronic Husband" article is one wife's attempt to quantify her husband's
interest in all things electronic by adapting forms of Ohm's Law to fit observed
behavior. In the process of writing the parody, Mrs. Jeanne DeGood demonstrates
an impressive basic knowledge of Mr. DeGood's second passion (Mrs. DeGood
being his first, presumably). After all the articles that Melanie has proof read
for me, she knows a lot of these equations just as well, even if she doesn't know
what they mean.
 Electro-Photonics is a market leader in RF
and Microwave components with extensive experience designing RF/microwave test fixtures
for a wide range of RF and microwave passive and active components. Model FRFS-AT-64020-001
is a high performance custom
RF/microwave fixture designed for testing Avago AT-64020 silicon bipolar transistor.
This fixture is constructed to provide repeatable measurements in a production environment.
The FRFS-AT-64020-001 test fixture feature fast load/unload clamshell type cover.
Electro-Photonics' standard line of test fixtures covers frequency ranges from DC
to 5 GHz frequency range has been introduced to facilitate your measurement
needs. We also design custom test fixtures for even the most technically challenging
high frequency applications. Our high performance test fixtures utilize the latest
RF materials and high frequency technology, resulting in repeatable and accurate
testing. Trust Electro-Photonics LLC to build your next RF and microwave test fixture...
 Electroluminescent (EL) devices were patented
by General Electric back in 1938, but it was not until the 1960s that the fabrication
process, involving copper-doped zinc sulfide (ZnS) as the light-emitting compound,
had developed to the point where high volume production was feasible. Early EL displays
exhibited short lifetimes and low efficiencies. EL panels are also referred to as
light-emitting capacitors because of their construction geometry. Some of the first
commercial applications for such EL panels were as back lighting in automobiles.
Electroluminescence can also be obtained in semiconductors in the III-V group class
like indium phosphide (InP), gallium arsenide (GaAs), and gallium nitride (GaN).
This 1965 Electronics World magazine article...
 Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, is pleased to introduce two new
90° power couplers, models IPP-7112 and IPP-7114. These surface mount couplers
are conservatively rated at 50 watts CW, and operate from 8.0−12.0 GHz and
6.0−12.0 GHz, respectively. The IPP-7112 and IPP-7114 product pages list the
complete product specs, and provide links to pdf files of the detailed Outline Drawings
and the Typical Test Data results for several parameters. In addition, these product
pages also offer links to the Simulated S-Parameters in s4p format, and the PCB
Mounting Footprint in dxf format. To view Technical Data Sheets in PDF format for
these products...
KR Electronics
3450-SMA Bandpass Filter
TotalTemp Technologies John Booher in Evaluation Engineering Special
Report: "Power
Semiconductor Testing."
Triad RF Systems Inc. announces partnership with Mobilicom to produce
High Power Radio Solutions
 Infographic "The Ins and Outs of Radio
Frequency "
RfCaFe
autodidacts
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. I also re-broadcast homepage items
on LinkedIn. If you need your company news to be seen, RF Cafe is the place
to be.
 RF Cascade Workbook 2018 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...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils 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). Stencils 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...
 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...
 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...
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 "A new universal theory and three basic rules
for how
defects in semiconductors behave in response to strain could lead to improvements
in the electronic properties of a wide range of semiconducting materials. The work,
which began with the discovery of a key physical quantity that describes how a semiconductor's
volume changes in the presence of impurities, could help researchers determine the
'right' amount of strain to apply, and thus optimize the effects of these impurities.
Defect-induced volume changes Most materials contain impurities, or dopants, that
are either intentionally or unintentionally introduced into the system - for example,
during the growth of a crystal..."
 "Researchers at Princeton University have
built the world's smallest
mechanically interlocked biological structure, a deceptively simple two-ring
chain made from tiny strands of amino acids called peptides. In a paper published
August 23 in Nature Chemistry, the team detailed a library of such structures made
in their lab - two interlocked rings, a ring on a dumbbell, a daisy chain and an
interlocked double lasso - each around one billionth of a meter in size. The study
also demonstrates that some of these structures can toggle between at least two
shapes, laying the groundwork for a biomolecular switch. 'We've been able to build
a bunch of structures that no one's been able to build before,' said A. James Link,
professor of chemical and biological engineering, the study's principal investigator...."
 "Forefront RF, a Cambridge-based fabless
semiconductor company, is set to change the way global smartphones, wearables, and
IoT devices are designed. They have developed a chip that enables connected devices
to operate across the increasingly wide range of 3G to 6G mobile telephony frequency
bands. Forefront RF's cancellation technology redesigns the radio frequency (RF)
system in a wireless device, enabling manufacturers to simplify the design and delivery
of
frequency agnostic products, whilst reducing cost and supply chain waste. Forefront
RF was founded in 2020 by Dr Leo Laughlin whose academic work in this field is widely
cited, together with Julian Hildersley who brings 30 years of experience in the
development and marketing of ground-breaking RF mobile phone technologies..."
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