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5 of the January 2023 homepage archives. Friday the 6th
 Railroads have played a fairly major role
in communications development. Beginning with carrying letter mail as cargo across
vast distances much more quickly than horse-drawn coaches and even Pony Express,
much of the early telegraph and then telephone electric lines were strung along
rail lines. Doing so facilitated initial installation as well as maintenance since
materials and personnel could be delivered quickly and conveniently. Many miles
of old telegraph lines can still be seen lurking in the trees and weeds along tracks
all over the country. Both telegraph and wireless communications were used to keep
in contact with trains to establish location, weather condition, equipment status,
indian uprisings, to enable messaging to and from passengers, and to provide navigation
instructions when the need arose. The world's first mobile radio broadcast took
place on a train. This 1960 "Railroad
Radio" article in Electronics World magazine reported on the state
of the art at the time...
 "Three researchers based in the USA and
the UK have reviewed the potential for applying multi-dimensional (multi-D) power
device architectures with a view to suggesting more appropriate figures of merit
(FOMs) compared with those applied to essentially 1D structures. Such FOMs are key
to assessing the performance limits and scaling capabilities of power devices. The
authors - Yuhao Zhang of Virginia Polytechnic Institute and State University (Virginia
Tech), Florin Udrea of the University of Cambridge, and Han Wang of the University
of Southern California - focus on
multi-D structures pioneered in silicon in an effort to beat off the competition
from potentially higher-power-capable but more expensive materials such as silicon
carbide (SiC) and gallium nitride (GaN): superjunctions (SJs), multi-channels, fin
field-effect transistor (FET), and trigate..."
 Atmospheric scientists suspected as recently
as early 1957 that Earth's upper atmosphere (ionosphere
and beyond) temperature might be around 1,000 °K. I say "suspected" because
we had not yet launched instruments there to make actual measurements. Soundly posited
and agreed upon theory was validated a short time later when sounding rockets reliably
reported a maximum of about 1,300 °K in the upper ionosphere. We did not know
for sure what electromagnetic wavelengths and their respective energy densities
would be outside the protective layers of gases encompassing Earth. Much more was
known about the depths of the planet's oceans than of its atmosphere. Scientists
knew that life was abundant below the water's surface but did not know what, if
any, life existed at altitudes any greater than the tallest mountain. Outer space,
devoid of everything we consider essential to support life as we know it, would
be a hostile environment for humans or even electronic instrumentation. It is always
interesting to recall that while you only need to dive 33 feet below the water's
surface to double the ambient pressure, you need to go 18,000 into the atmosphere
to halve the pressure. Beginning in 1957...
 Here's another news tidbit to tweak the
idiot who keeps harassing me for daring to claim
memristors are real
entities. "These brain-mimicking devices boast tiny energy budgets and hardened
circuits. Memristive devices that mimic neuron-connecting synapses could serve as
the hardware for neural networks that copy the way the brain learns. Now two new
studies may help solve key problems these components face not just with yields and
reliability, but with finding applications beyond neural nets. Memristors, or memory
resistors, are essentially switches that can remember which electric state they
were toggled to after their power is turned off. Scientists worldwide aim to use
memristors and similar components to build electronics that, like neurons, can both
compute and store data. Such brain-inspired neuromorphic hardware may also prove
ideal for implementing neural networks - AI systems increasingly finding use in
applications such as analyzing medical scans and empowering autonomous vehicles.
However, current memristive devices typically rely on emerging technologies with
low production yields and unreliable electronic performance..."
 Do you know what a
Fahnestock clip is? Chances are you would know one if you saw one, but you never
knew what it was called. This 1969 Popular Electronics magazine article, requested
by RF Cafe visitor Jan C., references a Fahnestock clip in the parts list for constructing
an easily tunable long-wire antenna. The simple circuit uses just a handful of components
for matching the high impedance antenna to a relatively low impedance coaxial cable
feeder. A flashlight bulb and a few turns of wire act as an RF sniffer to tune for
best match. A high quality ground is essential to the setup's operation so the author
describes using copper sulphate crystals or rock salt to treat the ground rod vicinity
for better conduction. It's a short article so go ahead and read it - if for no
other reason than to see what a Fahnestock clip is...
/jobs.htm">![Engineering Job Board - 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
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Thursday the 5th
 Thanks once again to Mr. Ferrous Steinke,
quite the
Carl & Jerry fan, for providing the following content regarding the technodrama
entitled "Operation Startled Starling," from the January 1955 issue of Popular
Electronics magazine. "Biosonics as a repelling technique are based on acoustical
signals emitted by birds and other animals to convey information to conspecifics.
Two audible bird warning stimuli, distress and alarm calls, have been explored and/or
used for acoustically repelling birds from urban and rural roosts, fish-rearing
ponds, airport runways , agricultural settings, and other locations. Distress calls
are those emitted by birds when being restrained, attacked by a predator, or subjected
to other types of severe conditions, whereas alarm or warning calls are usually
given in response to the presence of an intruder or predator. Depending on the species
and situation, these warning calls often cause conspecifics, and sometimes closely
related species, to leave the immediate area. The use of natural communication signals
to frighten birds has received considerable attention in the past several decades
for managing certain pest birds. They have the advantage of being more effective...
 The term
memristor - a portmanteau
of "memory" and "resistor" - is the fourth fundamental electronic component, along
with the resistor, capacitor, and inductor. The name was coined in 1971, which sounds
like yesterday to someone like me (born in 1958), but incredibly that is now half
a century ago. Until fairly recently, the memristor was merely a theoretical curiosity
existing in academic papers. In April of 2008, HP Labs (Hewlett-Packard) reported
on successfully building a nanoscale memristor in their R&D lab. As with all
new technologies, since that time much progress has been made. This conceptual diagram
illustrates the symmetry of the four basic circuit components - the resistor, the
capacitor, the inductor, and the memristor. Per Wikipedia: "Chua in his 1971 paper
identified a theoretical symmetry between the non-linear resistor (voltage vs. current),
non-linear capacitor (voltage vs. charge), and non-linear inductor (magnetic flux
linkage vs. current)...
 "The term,
positive current feedback, is disturbing to some because, as is well known,
positive feedback increases the distortion of an amplifier to which it is applied.
This is true in this application also, but it must be noted that the net feedback
applied to the amplifier is never positive but simply less negative in the region
where the positive current feedback is effective." Wow, that is a lot like what
politicians refer to a "baseline budgeting." When one political party says it is
going to "cut the budget," while the other complains that doing so will "starve
children" and "hurt women," what it really means is that spending will not be increased
this time as much as what had originally been planned, although it will actually
be higher than the last time. We know the government never actually spends less
money one year than it did the year before, but there are a lot of "low information"
people who never suspect a thing - just keep the welfare checks and food stamps
flowing...
 "What if there were a gadget that could
within short order check whether you have COVID or the flu - or maybe it would even
pick up that you have diabetes without knowing it? The device could figure all this
out without you having to go to a doctor or a laboratory. This technology could
become a reality within a few years, and electrical engineers are some of people
who make it possible to create such gadgets, which contain a key component called
the
whispering gallery mode microresonator. New technology is providing better optical
sensors, which are important for electronics, including devices that analyze chemicals
using light. 'We've built the lowest loss whispering gallery mode microresonator
out there for the longwave infrared spectrum. Because the longwave infrared spectrum
provides definitive information about chemicals..."
 Mechanical meter movements have been around
since the late 1800s. In 1882 Jacques-Arsène d'Arsonval and Marcel Deprez developed
a meter movement with a stationary permanent magnet and a moving coil of wire which
survives today as the dominant form. Lord Kelvin's (aka William Thompson) galvanometer
preceded d'Arsonval's by a decade or so, but it relied on the Earth's magnetic field
and needed to be properly oriented to work. d'Arsonval's movement incorporated a
permanent magnet instead to improve sensitivity and convenience. I'm not sure d'Arsonval
gets sole billing on the name - why not the Deprez movement? This article in Popular
Electronics magazine from 1960 is as relevant today as it was more than half a century
ago...
/jobs.htm">![Engineering Job Board - 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
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 The
Wireless Telecom Group,
comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer
of advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
Wednesday the 4th
 From the time the Wright brothers made their
historic 1903 flight at Kill Devil Hills on the coast of North Carolina, aviation
progressed at a geometric rate. For safety, convenience, and commercial reasons,
navigation methods and equipment necessarily developed alongside aircraft advances.
Both realms required a huge amount of innovation, research, and development. All
first-world countries participated in the effort in order to establish and/or maintain
leadership in particular realms of the science. One of the earliest
navigational aids was the creation of detailed maps with easily recognized landmarks,
and placement of flags and windsocks where they would be easily visible from an
airborne vantage point. That facilitated more accurate "dead reckoning" navigation.
Bonfires were built in specific locations for the benefit of night flyers. Next
came electronic navigational equipment like direction finding (zeroing in on a commercial
radio broadcast tower), omnidirectional (VOR and VORTAC) broadcast for flying bearing
relative to fixed stations broadcasting compass information...
 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 925.3 - 938.3 MHz cavity bandpass
filter with 1.5 dB insertion loss, a 988.5 MHz cavity bandpass filter
with 45 MHz bandwidth and 1.8 dB insertion loss, and a 1730 MHz cavity
bandpass filter with a 32 MHz bandwidth and 2.5 dB insertion loss. 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...
 "McWatts"
was an electronics-themed comic that appeared in Popular Electronics magazine
back in the late 1957's. Artist Carl Kohler's main character is a stereotypical
Joe Sixpack type electronics hobbyist who always dreams up unique ways to deal with
situations. This edition shows McWatts' way of keeping the kids from using his prized
tools as toys. My father would appreciate this if he had read Popular Electronics
back in the day. I was always leaving my poor father's tools laying around the house
and too often in the yard where they would get rained on and start to rust. If I
were him, I would have been harder on me for repeat offenses. Carl was also the
creator of the very popular series of humorous stories about an electronics-obsessed
husband and his barely tolerating wife...
 "Lightning flashes have distinctive zig-zag
shapes and physicists have long wondered why. Now, John Lowke and Endre Szili at
the University of South Australia have done calculations that could explain this
behaviour. The duo created a model that describes the unusual propagation of 'lightning
leaders' - channels of ionized air - that connect thunderclouds to the ground. They
propose that the zig-zag steps are associated with highly excited, metastable oxygen
atoms - which make it far easier for electrical current to flow through the air.
Lightning appears to propagate in a series of steps that involve leaders, which
are tens of metres long and originate from thunderclouds. A leader will light up
for about 1 µs as current flows, creating a step. Then the channel will darken for
tens of microseconds, followed by the formation of the next luminous step at the
end of the previous leader – sometimes with branching occurring. This process repeats
to create a familiar jagged lightning-bolt shape..."
 Even though the concept could easily be
demonstrated to be viable mathematically, single sideband operation was early on
widely regarded as an unrealizable laboratory curiosity, especially with a suppressed
carrier. More circuitry is of course needed to accomplish single sideband communications
both on the transmit and receive sides, but other than stricter stabilities and
precision for frequency sources, single sideband operation is easily obtainable.
Similar to back when this 1952 issue of QST published "The
Reception of Single-Sideband Signals," there still remains today a debate over
whether voice quality is as good versus double sideband, but there is no arguing
whether the spectral efficiency gained with single sideband is a great benefit to
the world. My first experience with single sideband, suppressed carrier operation
was while designing a modem for an Inmarsat base station installation in Connecticut.
At the time, there were no ICs available to do the job, so individual components
were used for the mixers, oscillators, and quadrature power splitters/combiners.
A potentiometer was used on the I channel (in-phase) to null out the carrier. Nowadays,
a single IC does the entire job, including often with an integrated filter...
 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 12,000 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.
 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.
Tuesday the 3rd
 The first installment of this two-part "Computer
Memory Devices" series discussed the use of magnetic data storage in the form
of drums and tapes. Both types provide long-term, non-volatile storage, but both
suffer from a relatively slow execution of writing and reading to and from, respectively,
the media. In 1960 when Electronics World magazine printed the articles, drums and
tape were used during execution of programs because electronic storage in the form
of vacuum tube circuits was extremely costly in terms of power, cost, and physical
space. As recently as the early 1980's, magnetic tape storage still dominated the
data storage field, especially where huge amounts on information needed to be stored
and retrieved. Semiconductor memory, while less voluminous and less power hungry,
still added a lot to the cost of computers. If you were around at the time and used
a PC, you remember that 64 kilobytes or RAM...
 David Goins, founder of and chief engineer
for Windfreak Technologies, has written a number of application notes pertaining
to the specification and testing of RF and microwave frequency signal generators.
"The
Ins and Outs of Radio Frequency" is addressed to people not familiar with the
concept of electromagnetic radiation, and uses a very nicely designed infographic
format to augment the brief textual discussion. It is a great classroom prop for
introducing middle and high school students to radio. "Radio frequencies are used
in a wide range of items, but most people do not understand how they work or are
used in our daily lives. A radio frequency is a type of electromagnetic energy and
is measured in hertz, and it is used by radars, radios, televisions, microwaves,
GPS, cells phones, and satellites. When you are buying these types of products,
you should look for items that come with warranties, are high in quality..."
 Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Vector
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments. 50 Ω and 75 Ω models are available, along with
a full line of precision calibration and connector adaptors.
 As one who recently installed an outdoor
antenna with a signal booster on it, I definitely considered whether my exercise
and investment would be worthwhile because all the preamplification in the world
wouldn't help if the signal-to-noise ratio was lousy to begin with. This statement
in Radio & Television News magazine from Mac McGregor, proprietor of
Mac's Radio Service Shop, sums it up well, "One thing you have to remember is
that the booster has to have something to boost. Unless the antenna can deliver
some sort of signal to it, it has nothing to work on. The results are about the
same as when a small boy reaches the bottom of his soda. He keeps on trying, but
about all his straw delivers is noise..."
 "Magnetic
tunnel junctions (MTJs), which consist of two ferromagnets separated by a non-magnetic
barrier material, are found in a host of technologies, including magnetic random-access
memories in computer hard disk drives as well as magnetic sensors, logic devices
and electrodes in spintronic devices. They do have a major drawback, though, which
is that they do not operate well when miniaturized to below 20 nm. Researchers in
China have now pushed this limit by developing a van der Waals MTJ based on a semiconducting
tungsten diselenide (WSe2) spacer layer less than 10 nm thick, sandwiched between
two ferromagnetic iron gallium telluride (Fe3GaTe2) electrodes. The new device also
has a large tunnel magnetoresistance (TMR) at 300 K, making it suitable for memory
applications..."
 "And there is nothing new under the sun."
- Ecclesiastes 1:9, NKJV (did you know this is the origin of the saying?). This
1930 editorial by Radio-Craft editor Hugo Gernsback describes a coordinated
scam perpetrated by radio manufacturers to compel consumers to buy new sets rather
than have their existing sets repaired; such schemes persist today. In short, retail
prices were inflated to accommodate a built-in "trade-in" allowance that far exceeded
the repair cost or used radio cost.
Radio service shops were getting the short shrift because many people who might
have otherwise elected to have repairs made would instead trade in the old set for
a new one. That a conspiracy was underfoot was evidenced both by the practice of
destroying traded-in sets so they cannot be used again (similar to the Cash for
Clunkers program where engines were destroyed after trade-in), and by making it
difficult or even impossible for repair shops to obtain adequate technical documentation.
The latter is a prime reason why magazines like Radio-Craft began publishing
Radio Service Data Sheets monthly...
 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.
Monday the 2nd
 In 1960 when this "Computer
Memory Devices" article appeared in Electronics World magazine, digital electronic
computers were still a relatively new technology. Although bulky and power-hungry,
accomplishing digital manipulations of data for logic, mathematics, sorting, etc.,
was relatively easy, but unless programming instructions were fixed and output was
used real-time, an ability to store data is necessary. Memory banks composed of
vacuum tubes could -and often did - do the job, but the data was neither permanent
nor physically transportable. If power is lost, the information is lost. We still
suffer that issue even today volatile type memory. For more permanent data storage,
magnetic media was developed, solving both aforementioned down sides...
Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Vector
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments. 50 Ω and 75 Ω models are available, along with
a full line of precision calibration and connector adaptors.
 If this article had appeared in an April
edition of Radio-Craft magazine, I might have suspected it was a Fool's
hoax, but it was the March 1933 issue and, it turns out, it was serious. Obviously
the "filamentless
tube" concept did not work out well since the overwhelming majority of vacuum
tubes sold up until the time semiconductors took over the electronic device market
had separate filaments (heaters). It was a great idea, though, and the world is
thankful for the pioneers who take the figurative "arrows" for the rest of us. We
benefit from their hard work and ingenuity, while they suffer the agony of defeat,
with an occasional taste of the thrill of victory (ref. ABC's Wide World of Sports).
It is too bad the concept did not work because, as pointed out in the article, the
benefits of simpler, cheaper manufacturing and greatly extended tube lifetime would
have been a significant asset to the electronics industry...
 Do you remember back in the mid to late
1990's when the World Wide Web (WWW) was just becoming a major "thing," and people
were buying up domain names in hopes of selling them later at astronomically high
prices? Back in those days there was no restriction on which domain name you could
claim, even if it was the name of a major company. Not every corporate honcho was
convinced that a time would come when having a website bearing the company name
would be essential. Not having someone else own it would be equally essential. I
read of cases where McDonalds and one of the auto makers paid big $$$ to buy domain
names from Joe Sixpack types with more foresight. Domain names like radio.com, travel.com
and realtor.com were fetching enviable prices as well. At the moment the
Radio.com domain name is up for auction. The starting bid is $2.5 million.
Here's your chance...
 Whoa! Take a look at the
RF feedthrough and lightning arresting choke on the feed line on the original
Voice of America transmitter in Munich, Germany. Now that is serious stuff. This
story from a 1959 issue of Popular Electronics reports on the extreme lengths
to which the Soviet bloc went in order to prevent its countrymen from hearing radio
signals broadcast by the Voice of America and other non-state-approved beacons.
Quarter megawatt transmitters sent messages of freedom that could be picked up by
even the most remote crystal sets that didn't have the advantage of amplification.
Ground-wave, sky-wave, and short-wave jamming techniques were employed to ensure
the only signal that could be received was a buzz-saw type noise. Not so long ago,
and certainly in 1959, America was viewed as a beacon of freedom, both figuratively
via word-of-mouth and underground newspapers, and literally via high powered radio
broadcasts directed into cordoned off countries ruled by Communist rulers. Herculean
efforts were made by the likes of Stalin, Khrushchev, Castro, Kim Il-sung, Pol Pot,
and various other despots to prevent any form of communications with the outside
world. I remember back when my grade school classmates and I were practicing hiding
under our desks in the event of a nuclear bomb attack...
/jobs.htm">![Engineering Job Board - 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
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...
 Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets
exceedingly high standards of quality, performance and excellent value, and are
100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz.
Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production.
All products are custom designed. We will find a solution and save your time and
cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Sunday the 1st
 This custom made
Electronics theme crossword puzzle for January 1st is provided compliments of
RF Cafe. A special message is included (marked with asterisk *). 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 puzzle
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 or the Tunguska event in Siberia). The technically inclined
cruciverbalists amongst us will appreciate the effort. Enjoy!
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
 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.
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. I also
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