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4 of the January 2022 homepage archives.
Monday the 31st
Reliance Test & Technology (RT&T),
a high-technology firm specializing in information systems, science and engineering,
and technical and administrative services, is seeking a
Telemetry Engineer for work at the National Radar Test Facility at White Sands
Missile Range. The Telemetry Engineer is responsible for the architectural design,
integration, testing and operation of telemetry systems for the Dynamic Range Measurement
System (DRMS). Experience with flight test instrumentation and telemetry (TM) systems,
telemetry ground stations such as the Advanced Range Data System (ARDS) and Data
Acquisition, Recording and Telemetry (DART) systems. Strong technical background
with technical problem-solving skills. Must be hands-on and capable of working with
limited to no supervision. Expert knowledge of systems engineering practices &
best practices...
"The
Gouy-Chapman
theory describes what happens near an electrode when it is in contact with a
salt solution, but this description does not match reality. Researcher Kasinath
Ojha, assistant professor Katharina Doblhoff-Dier and professor Marc Koper present
a new version. 'The next generation of textbooks on electrochemistry is going to
look different.' When you look inside a fuel cell, one of the things you will see
is an electrode, often made of platinum. This piece of metal is in contact with
a salt solution, which contains positively and negatively charged particles called
ions. If you were to zoom in on the interface between the electrode and the salt
solution, you would perceive all kinds of interactions. At the surface of the electrode,
a shortage or abundance of electrons exists..."
In order to facilitate searches for information
on vintage radios, I have been scanning and running OCR (optical character recognition)
on many of the Radio Service Data Sheets like this one featuring the
Philco Model 200-X, 10-tube high-fidelity superheterodyne model in graphical
format, rather than run OCR on them to separate the textual content. It appeared
in the December 1934 issue of Radio-Craft magazine. A fine restored example
of the Philco Model 200-X appears on the Radio Museum website. There are still many
people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information. A running list of all
data sheets can be found at the bottom of the page to facilitate a search...
Signal Hound recently updated its flagship
Spike software to include LTE Analysis Mode. Users and fans of the company's free
and heavily capable spectrum analyzer software will now find a highly useful LTE
measurement function in the package. The addition of an LTE utility to the core
spectrum analysis software package, Spike, aligns with Signal Hound's commitment
to its customers and users - to provide unrivaled value in the test equipment industry.
Spike contains an ever-growing list of analysis tools for measuring the world's
most popular communication signals, making Signal Hound and Spike the most cost-effective
solution for many communications and network engineers. Spike's new LTE measurements
allow for the monitoring and scanning of LTE downlink signals. Customers can monitor
a single frequency or define...
May 6, 1937, is the date of the Hindenburg
disaster at the Naval Air Station in Lakehurst, New Jersey, and is the RF Cafe logo
theme for that Day in History (see upper left page corner). Ironically, last night
while looking through the July 1936 edition of Radio-Craft magazine, I
saw this news article reporting on preparations being made in the onboard radio
and direction finding equipment for Hindenburg's maiden voyage from its home base
in Frankfurt, Germany to North America. No one at the time of this article suspected
such a terrible fate was looming less than a year later. Theories abound regarding
the cause of the fatal fire, but there is no doubt that a combination of highly
flammable hydrogen gas and an also highly flammable graphite dope (used to make
it conductive and lightning impervious) impregnated cloth envelope was responsible
for the incredibly rapid consumption...
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. 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 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.
Sunday the 30th
This custom made
Antenna theme crossword puzzle for January 30th is provided compliments of RF Cafe.
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!
Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
downconverters. Since the conception of WFT, we have introduced products that have
been purchased by a wide range of customers, from hobbyists to education facilities
to government agencies. Worldwide customers include Europe, Australia, and Asia.
Please contact Windfreak today to learn how they might help you with your current
project.
Friday the 28th
I didn't know that another name for a nomogram
(or nomograph) is an "abac," but thanks to Mr. Crowhust in this 1954 Radio-Electronics
magazine article I now do. At first I thought maybe it was a shortened version of
abacus, but I couldn't find anything suggesting that. Anyway, this article presents
a couple abacs you do not often (if ever) see - the attenuation and reflection levels
for
resistive attenuators when the impedance(s) are incorrect for the designed values.
Keep in mind, particularly when using off-the-shelf components like attenuators,
filters, power couplers and splitters, PIN switches, etc., that if your source and
load impedances are not exactly the same as the component input and output impedance
(usually 50 Ω or 75 Ω), the response will not be as advertised. Achieving
the proper performance will require inserting an impedance matching section...
"A study of electron dynamics timed to millionths
of a billionth of a second reveals the damage radiation can do on a molecular level.
The first-of-its kind study used
ultrafast
X-ray laser pulses to disrupt the electrons in a molecule of nitrous oxide and
measure the resultant changes with unprecedented accuracy. The work, published today
in Science, was performed at the Linac Coherent Light Source (LCLS) at the Stanford
Linear Accelerator Centre (SLAC), Stanford, U.S. and was supported by a team of
five scientists from Imperial College London. Conventional X-rays used in imaging
and radiotherapy can cause damage to cells, but exactly how on a molecular level
is not known. Additionally, new high-intensity and short-pulse-duration X-ray lasers
are being proposed to image smaller molecules with greater precision, leading to
questions about potential damage this could cause to living tissue. For the first
time..."
Precision Ruggedized VNA Cables from ConductRF
offer RF Engineers great alternatives to costly OEM cables that are now past their
best days. We have standards for applications at 18 GHz, 27 GHz, 40 GHz,
50 GHz & 70 GHz. Our torque resistant connector heads and phase stable
constructions ensure great performance for many tests to come. ConductRF VNA series
provides customers with reliable ruggedized solutions for Lab and Production Vector
Network Analyzer testing. With options for 18 GHz, 26.5 GHz, & 40 GHz,
these cables offer cost leading alternatives to original OEM VNA cable solutions.
VNA Series cables are enhanced with a stainless steel spiral armor, providing protection
from excess bending and crushing forces. A black non-conductive outer cover completes
the product. These cables are phase stable during flexing and have an operating
life cycle...
"We might say almost, that all modern scientific
investigation in the basic sciences, and a good deal of all practical developments,
are connected in some way or other with the electron." So writes Dr. Irving J. Sax
in this 1932 issue of Radio News magazine regarding the incentive for determining
as precisely as possible the
mass and electrical charge of an electron. The Bohr atomic model had just been
introduced two decades earlier, so the entire concept of particle physics was still
in its infancy. As with most areas of physics, experiments are conducted with particular
biases and expectations such that often the results are manipulated as needed to
conform to preconceptions. Look no further than the complex retrograde motion planetary
models devised and perfected by early astronomers who believed the universe revolved
around the Earth. It wasn't until a heliocentric model was accepted (following the
exile and execution of many "heretics") that orbital systems became simplified and
readily explainable. The same, to some extent, has been true of subatomic particle
physics, except digging deeper into the true nature of the beast has continually
revealed greater and greater complexity. Each time a new "fundamental" particle
is discovered through empirical testing, an new, more basic element is theorized...
CONATEL, the regulatory authority of Paraguay,
has chosen the
R&S AMS aerial monitoring system from Rohde & Schwarz to efficiently
verify the technical parameters of the ever-increasing number of microwave links
in the country. R&S AMS is a small, lightweight monitoring payload carried by
a commercial drone. This solution allows easy, economic and effective measurements
by flying inside the main lobe of microwave links that usually run horizontally
tens of meters above the ground and are otherwise very hard to access. The R&S
AMS payload comprises a spectrum analyzer, antenna, control computer, Wi-Fi unit
and battery pack. Having its own battery and data link make the payload independent
from the drone's infrastructure. Weighing less than 4.5 kg...
If you do repair or restoration work on electronics
assemblies with leaded components (i.e., not surface mount), large metal mounting
tabs, or other relatively high mass surfaces to be soldered and the surfaces are
contaminated and/or not easily tinned, then the advice offered in this 1951
Radio & Television News magazine article is well worth considering.
Acid flux is normally taboo around electronics, but, as author Herbert Brier
points out, there are instances where, with careful work, it can be used to create
surfaces which can then be soldered using standard rosin flux. The key is to use
the acid flux sparingly and being sure to thoroughly clean off the acid flux residue
before moving on to rosin flux. I have done this with both electronics and mechanical
parts (such as music wire for model airplane landing gear). I do NOT recommend ever
using acid flux on insulated wire if the flux can wick up under the insulation,
and NOT on stranded wire since the flux will get between the individual strands
and can eat away at it over time. An exception might be if the aforementioned wires
are just being tinned and can be placed in an ultrasonic cleaner...
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. 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 Superstore launched in 2017, marking
the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and
microwave Industry. Pasternack fundamentally changed the way RF components were
sold. Partner Jason Wright manages day-to-day operations, while working closely
with Mr. Pasternack to develop RF Superstore into a world class RF and
microwave
component supplier. RF coaxial connectors & adapters, coaxial cable &
cable assemblies, surge protectors, attenuators. Items added daily. Free shipping
on orders over $25. We're leading the way again!
Thursday the 27th
There is no such thing as too many articles
on the subject of
standing wave ratio. Standing waves were known and studied long before
their behavior in transmission lines was of concern. Although the Wikipedia entry
for standing waves credits Michael Faraday for first noticing them, undoubtedly
centuries prior to that scientists like Archimedes, Isaac Newton, and Descartes
observed and studied standing waves in ropes, vines, water, and other media. Author
Carl Drumeller went into a fair amount of detail with his description of the phenomenon
and the mathematical treatment of it, although he avoided the application of complex
numbers lest he scare away those unfamiliar with them (a wise decision). This is
one of the rare articles where voltage, current, and power standing wave descriptions
are provided...
"Atoms bind together by sharing electrons.
The way this happens depends on the atom types but also on conditions such as temperature
and pressure. In two-dimensional (2D) materials, such as graphene, atoms join along
a plane to form structures just one atom thick, which leads to fascinating properties
determined by quantum mechanics. Researchers at the University of Vienna in collaboration
with the Universities of Tübingen, Antwerp and CY Cergy Paris, together with Danubia
NanoTech, have produced a new 2D material made of
copper and iodine atoms sandwiched between two graphene sheets. The design of
new materials allows for either improved efficiency of known applications or totally
new applications that were out of reach with the previously existing materials..."
When this "Transistor
Roundup" article appeared in a 1961 issue of Popular Electronics magazine,
the world was just getting serious about the transition from vacuum tubes to semiconductors.
The slow take-up with solid state diodes and transistors was not simply a matter
of not wanting or trusting the newfangled technology; it was also a practical matter
of components being available which could be used in place of existing technology
from both a performance and price perspective. In looking through the transistor
parameter pages, the highest cutoff frequency I find is 800 mc (MHz),
which was pretty good for the day, but most topped out in the tens of MHz. Power
dissipation was a mere 75 mW, so that limited applications to low power oscillators,
switches, and amplifiers. As we now know, within a decade semiconductors would completely
replace tubes in new equipment except for high power and high voltage circuits...
Varian is a company familiar to most people
involved in early development of radar and other higher power microwave systems.
While the name sounds like a moniker construed from a combination of technical terms,
it is actually the surname of engineer brothers Russell H. and Sigurd F.
Varian. They are credited with building the first practical reflex klystron tube,
and its variant the
rhumbatron, while at Stanford University. Velocity modulation, the subject of
this 1939 QST magazine article, changes the speed of a stream of electrons
flowing at a constant current rate, rather than modulating the current. It was a
big deal that eventually found application in CRT displays for adding another dimension
to information on monochrome presentations...
Modelithics® is pleased to announce the release
of
version 21.9 of the Modelithics COMPLETE Library for Sonnet Suites. Modelithics
models represent discrete components that are typically very difficult to represent
with EM analysis, thus combining Modelithics circuit models with Sonnet Suites software
represents a "best of both worlds" simulation experience. This new release includes
the addition of 23 new models as well as compatibility with the latest version of
Sonnet (v18). The Modelithics COMPLETE Library for Sonnet Suites includes over 360
Microwave Global Models™ for capacitor, inductor, and resistor part series. Version
21.9 adds new models to the library for components from vendors such as AMOTECH,
Coilcraft, KEMET, Kyocera-AVX, Passive Plus, TDK, and Vishay, among others. Specifically,
new Microwave Global Models are included for the AMOTECH A60Z and A60L capacitor
series. Both models are validated to 50 GHz. Version 21.9 also includes new models
for the TDK CGA1A2C0G, CGA1A2X7R, and CGB1T3X5R0J104M capacitor series...
You probably read a while back of the San
Francisco's Bay Area Rapid Transit (BART - good acronym, as in Simpson) shutting
down cellphone service in order to thwart a rumored attempt to organize a flash
mob attack. 1st Amendment groups have sued BART over the action. Also in the news
has been the government's plan for being able to
shut down the
Internet in the event of a national emergency (defined as whatever they need
it to mean). We already know that Big Brother has the capability to universally
control both wired and wireless phone service. OnStar-equipped vehicles have been
shut down remotely by law enforcement. It all seems very Orwellian, but it began
before the publication of "1984" (in 1949). Did George just dream up the book's
theme of total government control and a lemming populace, or did it come from astute
observations of past behavior that was projected into the future? On December 8,
1941, the day after the Japanese attack on Pearl Harbor, the FCC issued a "Notice
to All Amateur Licensees" that began thusly: "All amateur licensees are hereby notified
that the Commission has ordered the immediate suspension of all amateur radio operation
in the continental United States...
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 (of course a gratuity will be graciously
accepted). 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 ...
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.
Wednesday the 26th
If a kid built a
Jacob's Ladder type of high voltage spark machine today and took it to school,
he would probably be accused of bringing a lethal weapon onto the grounds. An FBI
SWAT team would subsequently storm his house at 5:00 in the morning and drag him
and his family members out onto the front lawn in their pajamas and conduct a thorough
search of the premises for other such weapons of mass destruction. The mainstream
media would all be there, having been tipped off by the Feds. In the 1970s when
I was in junior high school in Annapolis, Maryland, a couple times a year one of
us electrical tinkerers would show up with one to amaze and, to be honest, scare
fellow students. Mine was housed in a shoebox and was barely powerful enough to
generate a respectable climbing arc on a dry winter day...
"Researchers in China have developed an
adaptive liquid
lens based on dibutyl adipate (DBA), a new electrically responsive fluid that
changes focal length when a voltage is applied. According to the team, the lens
is suitable for mobile phone cameras, endoscopes, eyeglasses and machine vision
applications because it is lightweight, compact and simple to fabricate. 'The human
eye can arbitrarily focus on objects at different distances at incredibly fast speeds,'
said research team leader Miao Xu from Hefei University of Technology. 'Inspired
by this functionality, we developed an eye-like adaptive liquid lens that can be
used to diverge or converge light by changing the shape of the DBA liquid.' In Optics
Letters, the researchers describe their new DBA-based adaptive liquid lens..."
Planar Monolithic Industries (PMI) recently
introduced six new products in their extensive line of
RF and microwave components. Included are a DC to 40 GHz absorptive, SPST
PIN diode switch; a 110 to 210 MHz frequency discriminator; a 0.5 to 18.0 GHz
non-reflective, 10 bit, 60 dB PIN diode attenuator; a 160 MHz frequency
discriminator; a 0.1 to 50.0 GHz SP8T absorptive switch; and a 26.5 to 40.0 GHz,
passive amplitude equalizer with a negative slope. Contact PMI today for more information...
Hogarth is a comic character invented by
the
Echophone
Radio Company. Their bespectacled Army grunt was one of the first technology
nerd types who always managed to appear with pretty girls. His caricature evolved
quickly over the two or three year run of the advertisements in electronics magazine.
Most Echophone Radio ads I have seen either feature Hogarth and his woman/women
or Hogarth and a demanding sergeant. This full-page advertisement appeared in the
June 1945 edition of Radio-Craft magazine. Echophone radios can still be
found on eBay for fairly low prices - often less than the shipping cost...
Rohde & Schwarz will equip the German
Navy's NH90 Multi-Role Frigate Helicopter (MRFH), with
SOVERON family airborne radios that include embedded COMSEC. Each aircraft is
fitted with three VHF/UHF transceivers plus spares. The navy will receive 31 helicopters
- a naval version of the NH90 - that offer close-range protection, anti-surface-warfare
(ASuW) und anti-submarine-warfare (ASW), transport, and search and rescue capabilities.
The SOVERON family airborne transceiver uses state-of-the-art communications algorithms
that were standardized throughout NATO, and particularly for naval applications.
The transceiver's interfaces...
7-year-old Sharon Pakinas was celebrated
as the
youngest licensed female - aka "YL" (young lady) - Ham radio operator in 1953.
That was quite an accomplishment considering that she had to not only pass the written
test which included FCC regulations, operational guidelines, electrical theory,
but also pass a 5 word-per-minute Morse code test! From what I can find in a Google
search, the current youngest licensed girl is 5½-year-old Rosalie White, from Long
Beach, California, who earned her ticket in 1991 while a 5 WPM code test was still
required. In 1991, the Morse code test for the Technician level license was removed,
allowing easier access to Ham radio. The FCC dropped the Morse code requirement
for all license levels in 2007...
The advent of FET-input
multimeters greatly reduced reading accuracy errors due to not taking into account
the impedance of devices being measured. A certain amount of familiarity with how
to interpret the indication on a meter movement on analog meters is still required
based on the multiplier switch position and scale selected, but for most users simply
reading the number beneath the pointer - or interpolating its position between two
numbers - is good enough. Mirrored scales take the some of guesswork out of that
by reducing parallax issues. Finally, digital multimeters (DMMs) hit the scene and
made slackers out of just about all of us when it comes to making voltage, current,
and resistance measurements. With few exceptions, only production test, research,
and metrology environments require pulling out the meter specifications to determine
precision and accuracy numbers...
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!
Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas.
Tuesday the 25th
Before a plethora of readily available and
affordable electronic and mechanical components of all sorts was at your fingertips
(on a keyboard), often times project builders and repairmen either did without,
substituted "close enough" parts, waited a long time for mail order, drove long
distances to a supply house, or did like
Carl and Jerry did in this May 1960 Popular Electronics magazine adventure
- they modified on-hand equipment to suit the need. Replacing the center conductor
of a length of RG-58 coaxial cable in order to change its capacitance (and impedance)
might seem like an extreme measure to take, but half a century go it was de rigueur
with hobbyist of all sorts. Magazines of the era nearly always had monthly hints,
kinks, tip, and suggestions features, enthusiastically provided by readers who had
already reaffirmed the old adage of necessity being the mother of invention. As
is author John Frye's normal practice...
"Thales has partnered with the climate and
aerospace research project Airbus Perlan Mission II, with plans to create the 'highest
ever Wi-Fi hotspot.' Airbus Perlan Mission II Through the partnership, Thales
will aim to fly its latest mobile satellite communications system, FlytLink, in
a zero-emission glider to more than twice the altitude of a commercial airline flight.
Based in Nevada, the Airbus Perlan Mission II team is planning for a possible return
to flight this year in the US and El Calafate, Argentina. The group has already
set aviation world altitude records in the Perlan 2 glider, which was designed,
built and deployed to fly to 90,000ft. Launched in 2015, the Perlan 2 achieved its
highest record-setting flight of above 76,000 in 2018. The organisation's mission
is to conduct climate, atmospheric and aeronautical research at extreme high altitudes.
Applications of its research include informing more accurate climate change models,
innovating zero-emission aviation and demonstrating feasibility of using energy-efficient
winged aircraft on Mars..."
During my daily technical headlines search,
one of the websites I regularly visit is Radio Ink. As a lifelong fan of over-the-air
broadcast radio (and TV), it is interesting to see what trends are playing themselves
out.
OTA (over the air) broadcasting is struggling to survive in this modern world
of Podcasts and Internet streaming broadcasts; indeed, I do a lot of my radio listening
via the Internet because the local stations don't provide what I want. The Big Media
types are involved in a major lobbying effort to mandate FM radio receivers in all
cellphones, which of course is a prime example of corporate chieftains using their
financial might to pay off politicians for something that the rest of us will ultimately
have to foot the bill for. Radio's early days faced no such dilemma. People the
world over were excited about the advent of radio and eagerly awaited their favorite
broadcasts each day...
RF Superstore offers a wide selection
of popular
coaxial
cable in bulk lengths at exceptional prices - order by the foot for any custom
length needed for your project. RF coaxial connectors are available for terminations.
RF Superstore also offers power couplers, attenuators, terminations, DC blocks,
surge protectors, waveguide, and more. The launch of RF Superstore in 2017 marked
the return of Murray Pasternack to the RF and Microwave Industry. As founder and
CEO of Pasternack Enterprises from 1972 to 1992, Mr. Pasternack fundamentally changed
the way RF components were sold throughout the industry. His signature catalog greatly
simplified the ordering process and became the industry standard for RF component
sales. We're leading the way again...
Some people like to demean engineers and
scientists for their propensity to want to conduct experiments and obtain measured,
empirical data rather than "winging it" and being satisfied with intuitive knowledge
or the contemporarily popular term "gut." If mankind had not adopted scientific
methods and ventured beyond the so-called cradle of civilization on the African
continent, we would all still be living in grass huts, hurling rocks at prey, and
foraging for berries.
Quantifying and categorizing all things in nature helps inventors create new
and improved implements that help make life better. Early on it was mostly individuals
like Archimedes, Euler, Newton, and Edison who built the pool of knowledge that
fed and evolved into corporations, governments, and universities doing the vast
majority of the work. Bell Laboratories is probably one of the most recognizable
names for a group of people that collectively produced an immense amount of data
and products...
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 stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
SF Circuits' specialty is in the complex,
advanced technology of PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
Monday the 24th
This "R/C
Triplex: Three Channels on One Channel" article that appeared in a 1956 issue
of Popular Electronics magazine was written by a fellow who was well known in the
aeromodeling world at the time - Claude McCullough. Claude won many titles in precision
scale for both control line (C/L) and radio control (R/C). As was the case with
many R/C modelers of the era, he did a lot of experimentation with transmitters,
receivers, and electromechanical devices used to move control surfaces. Rubber-band-powered
escapements dominated the field, but some servomechanisms were being developed to
provide a means for proportional control and/or a more powerful means of multiposition
control. As can be seen in the video I produced showing how a typical escapement
worked, the output drove the airplane's rudder to either neutral, full left, or
full right deflections, with no position in-between. To actuate the control, the
R/C pilot pushed a button on the transmitter the number of times required to affect
the desired control movement. That made for somewhat jerky flights, but it was a
very popular setup...
"When scientists discovered DNA and learned
how to control it, not only science but society was revolutionized. Today researchers
and the medical industry routinely create artificial DNA structures for many purposes,
including diagnosis and treatment of diseases. Now an international research team
reports to have created a
powerful supermolecule with the potential to further revolutionize science.
The work is published in Nature Communications. The researchers describe their supermolecule
as a marriage between DNA and peptides. DNA is one of the most important biomolecules,
and so are peptides; peptide structures are used, among other things, to create
artificial proteins and various nanostructures. 'If you combine these two, as we
have, you get a very powerful molecular tool..."
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.
Most of the articles include features and applications for Windfreak Technologies
products, but the concepts are universally applicable. His latest, "Testing
RF Generators for Reliability" is featured here. It begins: "We pride ourselves
in designing, building, and selling high value radio frequency products that are
thoroughly evaluated and tested. All of our products go through rigorous testing
before releasing to our customers. Our devices have proven to be very reliable.
In rare cases, we have had a product come back for repair caused by output amplifier
failures. In this post, we explain the testing process we go through to ensure our
high-quality products and the two reasons for output amplifier failures..."
"What are these devices?" "How do they work?"
"What are their characteristics?" "How are they used?" Those are the kinds of questions
about
semiconductor diodes posed - and answered - in this article in a 1961 issue
of Popular Electronics. Author Jim Kyle runs through a short history of
he diode and then delves with more detail into physical construction, I-V curves,
power handling, junctions capacitance, resistance, etc. An interesting point mentioned
is that while a semiconductor diode will conduct some finite amount of current when
biased in the reverse direction (sometimes a desired characteristic), a vacuum tube
diode will not conduct at all when reverse biased - thereby making the tube a more
perfect rectifier...
Westinghouse's motive for dubbing the
Model WR-8 the "Columnaire" is apparent when you see a photograph of it. This
model also had a -R version with remote control. The remote, though, has a cable
attached to it; it's not wireless like today's remote controls. There are some very
nice photos of a fully restored WR-8-R version on the AntiqueRadios.com website
forum. Look about half-way down the page. Near the bottom of the page is a copy
of an advertisement for the Westinghouse WR-8 with a price of $193 (~$3,563 in 2022
money per the BLS Inflation Calculator). The fundamental circuit of these receivers
is the WRV5 receiver chassis and power pack shown in Data Sheet No. 29. The model
WR-6 is a highboy; its circuit is the same as used in the WR-6, except as modified
for tone control. The Model WR-7 is similar to the model WR-6, except as modified
for an electric phonograph...
In response to my solicitation for information
on the origin of band letter
designations, a website visitor offered this: "I just looked at your web page
that gives the names of the various RF bands, and, in one place asked for any information
on origins of the names. I have some history on the band names that apply to UHF
and above. In the early days of radar (during WWII), the British and the U.S. researchers
at MIT chose, arbitrarily I believe, letter designations for radar frequencies.
The frequencies that were then possible to use for radio communication were just
called by their 'meter range' names: HF, VHF and UHF. The new frequencies that were
then only used for deployable radar sets, and for new technology looking for even
shorter wavelength radars, were given letter designations. So, in the 1940s and
1950s, radar sets were identified as being UHF, L-Band, S-Band, C-Band, X-Band and
K-Band. Later they added Ku-Band - presumably for 'K Upper,' but I do not know..."
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...
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.
Sunday the 23rd
This January 23rd custom made
crossword puzzle has an Amateur Radio theme, compliments of RF Cafe. 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!
There are not many technical realms where
Google engineers have not either entered or created. Wireless connectivity is key
to their continued dominance in the information domain, so they understandably have
a vested interest in the "white space"
spectrum debate. White space comprises portions of the electromagnetic spectrum
where bands are either unlicensed or where licensed bands are or will be up for
grabs. An example of the former is the 2.4 GHz Wi-Fi band, and an example of
the latter is some parts of the broadcast television band that is being vacated
in areas. Although this information is a few years old, it shows how Google was
working early-on with the Federal Communications Commission (FCC) to build a real-time
database of what they term "dynamic spectrum" in order to provide useful information
about available white space (now directs here) to both users and providers. A separate
database is available for fixed and mobile spectrum. Enter your location of interest
and the map zooms into that region. For instance, in my town (at the time) of Erie,
Pennsylvania (see marker on map below), as of January 2013 when this was first posted
there were 21 channels available...
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...
![Reactel Filters - RF Cafe](../../../vendors/sponsors/reactel/images/reactel-products-hp.gif)
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
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