See Page 1 |
2 |
3 |
4 | of the April 2020 homepage archives. Friday 1
 Whether you are a DIY'er, tinkerer, hobbyist,
experimenter, roustabout, odd-jobber, handyman, jack-of-all-trades, innovator, or
any sort of electronics dilettante to any degree of adeptness from mere abecedarian
to seasoned professional polymath, chances are you can learn something useful from
just about all of John T. Frye's "Mac's
Radio Service Shop" techno-drama stories. They appeared on a monthly basis in
Radio & TV News magazine, and then continued when it became Electronics
World in 1959. The varied collection of "dogs" that piled up on Barney's bench
while Mac was on vacation provided a convenient excuse to touch on a wide variety
of equipment types, from record players to radios, including sets that had fallen
victim to "home-talentitis" at the hands of a not-so-capable owner...
 Fairview Microwave, an Infinite Electronics
brand and a leading provider of on-demand RF, microwave and millimeter wave components,
has launched a new series of
waveguide shorts and shims that are ideal for use in test and instrumentation,
wireless communication, satellite communication and radar applications. Fairview's
new line of waveguide shorts and shims includes 36 models offered in waveguide sizes
ranging from WR-430 to WR-10. This new line is ideal for use in RF test and measurement
applications and provides superior RF performance. Waveguide shims and shorts, or
shorting plates, are commonly included in calibration kits and they are used in
calibration applications. Waveguide shims can also be used to bridge gaps between
waveguide components. These waveguide shims and shorts are compatible with square
and round UG cover and CPR-style flanges...
 The National Company, of Malden, Massachusetts,
which made this
cesium-based Atomichron in the mid-to-late 1950s, began life as a toy manufacturer.
It had an output frequency at the nominal resonance frequency of cesium - 9192.631830 MHz
- and was accurate to better than a second in 600 years. The unit was 7 feet tall
and weighed 500 pounds. Modern cesium standards are more stable and are portable.
As of January 2013, the NIST-F1 cesium fountain primary frequency standard is accurate
to within one second every 100 million years! That's a tad better than the Atomichron,
non?
 "The Space Development Agency plans to award
contracts for a mesh network in space this August, with the expectation that an
initial batch of
20 satellites will be placed on orbit during summer 2022. The agency expects
to release a request for proposals for the contracts May 1. The announcement came
during an industry day the agency hosted over the phone April 2. The industry day
was originally slated to take place during the 36th Space Symposium in Colorado
Springs April 2, however, after that event was cancelled due to the circumstances
with COVID-19 the agency opted to hold a virtual industry day instead. According
to SDA Director Derek Tournear, 580 people called in for the event. That first batch
will include 20 satellites and will comprise what Pentagon leaders are calling Tranche
0 of the SDA's Transport Layer, a mesh network of satellites operating primarily
in low earth orbit..."
 3D Smith chart progenitor Andrei Muller
and some of his associates have published a paper on the ACS website entitled, "Radio-Frequency Characteristics
of Ge-doped Vanadium Dioxide Thin Films with Increased Transition Temperature."
It begins: "This work investigates and reports on the radio-frequency (RF) behavior
in the frequency range of 5-35 GHz of germanium-doped vanadium dioxide (Ge-doped
VO2) thin films deposited on silicon substrates via sputtering and pulsed
laser deposition (PLD) with estimated Ge concentrations of 5 and 5.5%. Both films
exhibit critical transition temperatures (Tc) of 76.2 and 72 °C, respectively,
which are higher compared to that of the undoped VO2 which undergoes reversible
insulator-to-metal phase transition at 68 °C. Both types of Ge-doped films
show low hysteresis..."
 Axiom Test Equipment allows you to
rent
or buy
test equipment, repair
test equipment, or
sell or trade test equipment. They are committed to providing superior customer
service and high quality electronic test equipment. Axiom offers customers several
practical, efficient, and cost effective solutions for their projects' TE needs
and is committed to providing superior customer service and high quality electronic
test equipment. For anyone seeking a way to offload surplus or obsolete equipment,
they offer a trade-in program or they will buy the equipment from you. Some vintage
items are available fully calibrated. Please check out Axiom Test Equipment today!
Thursday 30
 For many years, I have been scanning and
posting schematics & parts lists like this one that appeared in radio and electronics
magazines in the middle of the last century. Most use vacuum tubes. This
General Electric Model 280 Farm Radio "Radio Data Sheet" was in the May 1947
issue of Radio-Craft. The Radio Museum website has more information on the GE Model
280 Farm Radio. Farm radios were designed to work on storage batteries since until
the Rural Electrification Act of 1936 was put into effect, most rural properties
had no commercial AC electric power service. 11 years later, work was in progress
to light up the entire country, but many locations had to wait while resources went
to service war production needs. No actual example of the Farm Radio could be found
online. There are still many people who restore and service these vintage radios...
 Lemos International Technologies is
both a designer and manufacturer of wireless products and a distributor of products
from other world-class manufacturers. A modular approach to wireless connectivity
helps eliminate much of the technical design and testing and also simplifies or
eliminates the need for expensive conformance testing and certification. Ready-to-use
Bluetooth, GPS, Wi-Fi, licensed and unlicensed band products are available. Custom
design services can help you achieve success with your project's unique needs.
 Artech House today announced the publication
of
Basic Radar Analysis, Second Edition by Mervin Budge and Shawn German. This
2nd edition covers several key radar analysis areas, including the radar range equation,
detection theory, ambiguity functions, waveforms, antennas, active arrays, receivers,
signal processors, CFAR and chaff analysis. Analog signal processors and digital
signal processors of the types used in modern phased array radars are discussed.
Fundamentals of radar analysis including the range equation, detection theory, ambiguity
functions, antennas, receivers, and signal processors for modern radars are also
covered. This book addresses details of the radar range and detection probability
equations and the tools radar engineers commonly use to perform signal processor
and clutter analyses. Packed with details on how to perform radar range equation
and detection analyses, RCS modeling...
 Back in the early 1990s, while working for
a fine Midwestern company that made automated utility meter reading (AMR) equipment,
an older gentleman was hired as a contractor to do some design work. He was an instant
hit with everyone not just because of his engineering prowess, but because of his
stories of the mechanical and analog electronic computers he worked on for the U.S.
Navy. After being commissioned as an ensign at the U.S. Naval Academy in Annapolis,
Maryland, he spent time studying, researching, and designing massive
radar-directed gun pointing systems for battleships. Just as contraptions like
Babbage's difference engine was a marvel of contemporary engineering, so, too, were
those fantastic shipboard amalgamations of gears, switches, vacuum tubes, rheostats,
flywheels, cams, and bearings. Calculations of azimuths and elevations were made
using sum, difference, integrating, and multiplication circuits built of discrete
analog components and electronic valves...
 "Reliable
indoor mobile coverage can ease home broadband capacity challenges during the global
health crisis. As the regular rules for business and social interactions are being
torn to shreds as a result of the Coronavirus pandemic, homeworking is an important
lifeline for U.K. companies trying to maintain some sort of 'normality' for their
businesses and employees. Organisations that have previously avoided or discouraged
remote working for fear of motivational issues have been forced to rethink their
attitudes to home working since the country went into lockdown. Similarly, those
that have historically only permitted hybrid working under special circumstances
have had to formulate a feasible homeworking framework almost overnight, offer guidance
on implementation and come up with innovative ideas..."
 Centric RF is a company offering from stock
various RF and Microwave coaxial
components, including attenuators, adapters, cable assemblies, terminations,
power dividers, and more. We believe in offering high performance parts from stock
at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500
watts are available off the shelf. Order today, ship today! Centric RF is currently
looking for vendors to partner with them. Please visit Centric RF today.
Wednesday 29
 Here are a couple new-old
tech-themed comics from vintage Popular Electronics magazines. Both
have a Ham radio theme, so maybe you need to have been there to appreciate the scenario...
or maybe not. It is possible that the presence of clothes pins on twin lead or ladder
line could de-tune the line, and could crush the internal dielectric of a coaxial
line. There is no metal on boxer shorts, but maybe the clothes pins are the type
with a metal spring. For the other comic, you just need to know what ••• --- •••
is to get it. Enjoy
 Here is an interesting idea from the world
of astronomy - a
Lunar Crater Radio Telescope. RF Cafe visitor
Alan Dewey sent me this article on
plans to build a 1 km diameter radio telescope, operating in the 5 to 100 m
wavelength band, in a crater on the far side of the moon. That will facilitate blocking
of Earth-origin radio emissions from the telescope's super-sensitive receiver. Unlike
the 60-year-old 1,000 meter
Arecibo Observatory
radio telescope, the moon-base instrument will sweep a much larger area of the sky
and at a greater frequency than its Earth-based relative. "An ultra-long-wavelength
radio telescope on the far-side of the Moon has tremendous advantages compared to
Earth-based and Earth-orbiting telescopes, including: (i) Such a telescope can observe
the universe at wavelengths greater than 10 m (i.e., frequencies below 30 MHz),
which are reflected by the Earth's ionosphere and are hitherto largely unexplored
by humans..."
 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 ...
When Do You Expect Your
Business to Return to Normal?
 This is a bummer of a poll done by The Engineer
website asking UK engineering and manufacturing businesses, "When, if at all, do
you expect a return to business as usual?" 13% said never, and 79% said 3-18
months. It's not looking good in the UK or in the U.S. "Do you work in the UK engineering
or manufacturing sectors? If so, when – if at all – do you expect a return to 'business
as usual' once COVID-19 lockdown restrictions are lifted?"
 Withwave's
Precision Test Adapters with Right Angle types are designed based on precision
microwave interconnection technologies. These adapters are manufactured to precise
microwave specifications and constructed with male and female gender on both side.
The precision microwave connector interfaces ensure an excellent microwave performance
up to 40 GHz. Features include a frequency range of DC to 40 GHz, VSWR
of 1.20:1 (max) @40 GHz, and body made of passivated stainless steel...
 "PCBs? We ain't got no PCBs in our TV sets†...
We don't have to give you no stinking PCBs." That is effectively what the Zenith
television advertisement from a 1958 edition of Radio-Electronics told its potential
customers. According to the Zenith communications department, even though their
head R&D guy, Dr. Alexander Ellett, was "the
daddy of printed circuit boards," they stuck with the traditional point-to-point
wiring in all their TV chassis. I have to agree with them from a troubleshooting
and component replacement perspective. There's nothing easier than heating a solder
lug or terminal post to unwrap a leaded R, L, or C either to measure its value,
isolate it from the rest of the circuit for making tests, or to replace it. There
is no worry about solder splatter or bridges, overheating the PCB material to cause
delamination, or lifting metal traces from the surface. There is also no issue with
getting a component lead out of a plated-through hole. Yes, of course modern circuits
need multilayer, high density circuit boards...
 Since 1961, MECA
Electronics has designed and manufactured an extensive line of
RF & microwave components
for in-building, satellite, radar, radio, telemetry, mobile radio, aviation &
ATC. Attenuators, directional & hybrid couplers, isolators & circulators,
power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables.
MECA has long been the 'backbone' of high performance wired and air-interfaced networks
such as in-building applications, satellite communications, radar, radio communications,
telemetry applications, mobile radio, aviation & air traffic communications.
Tuesday 28
 As this is written, we in the U.S. are nearing
the end (hopefully) of the virtual house arrest period most of the country has had
imposed upon us by overzealous politicians. Part of the "comeback" plan being bandied
about by governors is requiring subjects/citizens to don
cloth face masks when in public places where the arbitrarily conjured up six-foot
"social distancing" rule cannot be easily maintained. Think of the cloth face mask
as the equivalent of an ankle bracelet when venturing outside. There is no foreseeable
end to this "new normal" imposed upon most of the world. Contrary to what many people
believe, the mask's purpose is not to prevent the wearer from inhaling COVID-19
(aka Wuhan Virus, China Virus, CCP Virus - pick your favorite) particles, but to arrest the
body fluids emanating from the wearer's mouth and nose from being spewed into the
air and/or onto surfaces. In response to the shortage of N95 type masks that are
supposed to stop up to 95% of virus particles, many private citizens - mostly women
- worked with health care personnel to design cloth masks that are comfortable to
wear for long periods of time and are reusable by washing them...
 Skyworks is pleased to introduce the
SKY5®-5242-11 a dual 2.4 GHz, 802.11ax high-linearity, high-efficiency
front-end module (FEM) designed for Wi-Fi 6 enabled devices including handsets,
tablets and mobile devices supporting WLAN and Bluetooth® protocols. This highly
integrated FEM includes two transmit and receive chains, an extremely low EVM floor
power amplifier, low noise amplifier with bypass, and a SP3T antenna switch. The
three transmit modes for high linearity, high efficiency and low gain provide optimal
performance. The SKY55242-11 builds on Skyworks' portfolio of revolutionary products
for 5G applications...
 "Despite the time spent with smartphones
and social media, young people today are
just as
socially skilled as those from the previous generation, a new study suggests.
Despite the time spent with smartphones and social media, young people today are
just as socially skilled as those from the previous generation, a new study suggests.
Researchers compared teacher and parent evaluations of children who started kindergarten
in 1998 - six years before Facebook launched - with those who began school in 2010,
when the first iPad debuted. Results showed both groups of kids were rated similarly
on interpersonal skills such as the ability to form and maintain friendships and
get along with people who are different. They were also rated similarly on self-control,
such as the ability to regulate their temper..."
 Meteor (burst) scatter communications is
an excellent example of where hobbyists - in this case amateur radio operators -
have contributed mightily to technology. It could be argued that a big part of the
reason for such occasions is that many people involved in science type hobbies are
employed professionally in a similar capacity, and their extracurricular activities
are a natural extension of what pays for the pastimes. It seems amazing to me that
meteor scatter as a means of achieving upper atmosphere reflections of radio signals
went undiscovered until 1953, but evidently that is the case. Meteor scatter is
a very popular form of amateur radio challenge these days, with much activity when
the bigger meteor showers are underway. Prior to 1953, meteor shower study was the
sole domain of astronomers...
 Andrei Muller, co-progenitor of the 3D Smith
chart, and a few of his fellow engineers recently published in Nature magazine
an article entitled, "3D Smith charts scattering
parameters frequency-dependent orientation analysis and complex-scalar multi-parameter
characterization applied to Peano reconfigurable vanadium dioxide inductors."
It begins, "Recently, the field of Metal-Insulator-Transition (MIT) materials has
emerged as an unconventional solution for novel energy efficient electronic functions,
such as steep slope subthermionic switches, neuromorphic hardware, reconfigurable
radiofrequency functions, new types of sensors, terahertz and optoelectronic devices.
Employing radiofrequency (RF) electronic circuits with a MIT material like vanadium
Dioxide, VO2, requires appropriate characterization tools and fabrication
processes. In this work, we develop and use 3D Smith charts for devices and circuits
having complex frequency dependences..."
 ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test Cables
for labs. ConductRF makes production and test coax cable assemblies for amplitude
and phased matched VNA applications as well as standard & precision RF connectors.
Over 1,000 solutions for low PIM in-building to choose from in the iBwave component
library. They also provide custom coax solutions for applications where some standard
just won't do. A partnership with Newark assures fast, reliable access. Please visit
ConductRF today to see
how they can help your project!
Monday 27
 Before the days of cheap stuff from China
(now including exotic viruses that cause politicians to shut down entire economies),
the supply of most common items- particularly high technology - were the domain
of relatively few companies. In some ways it was not entirely a bad thing because,
at least theoretically, the economy of scale enabled larger producers to leverage
bulk buying, well-equipped development labs and manufacturing equipment, and pooling
of talent resources to sell quality products at a lower price. Of course it required
that the company had serious competitors or monopolistic tendencies resulted in
gouging - it's human nature, unfortunately. Hewlett Packed, as much as I appreciate
what the company did for
electronics test equipment, had gotten out of hand with its prices until Tektronix,
Rohde & Schwarz, Fluke, Berkeley Nucleonics, Simpson, Boonton, Triplet, EICO,
Bird, and even RCA began introducing similar equipment at lower prices...
 As a designated critical industry, ConductRF
continues to operate at full capacity during the COVID-19 pandemic. ConductRF offers
a full line of
D38999, RF and mixed signal cable solutions with performance up to 65 GHz.
D38999 cables are one of our flag ship product capabilities. Standard features include
M85049 backshells, RF contacts for #8, #12 & #16 gauge, BMA & SMPM solutions,
low loss cable types, phase matching available. Custom marking and serialization
also available. Made in the USA. ConductRF coaxial cable assemblies are available
for immediate purchase from
Digi-Key.
 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.
 Breaking news from May 1958: "Hardly a month
passes nowadays without the announcement of some 'sensational' new amplifying device.
The great majority of these startling inventions, after their brief flurry in the
popular and technical press, disappear into oblivion. But we believe that the
Tecnetron, just announced in France, has a brilliant and enduring future." Have
you ever heard of a Tecnetron? I didn't think so; neither had I before reading this
article in Radio-Electronics. I guess that pretty much negates the preceding prediction.
The holy grail of the Tecnetron, whose etymology in and of itself is worth reading
about (it's not what you would guess), is that its transconductance increases with
frequency. Construction is such that although it is fabricated from a shaped rod
of germanium, it has a current controlling component that acts like a cross between
a triode vacuum tube and a depletion mode field effect transistor. My guess is that
the rapid improvement of standard semiconductor junction field effect transistors
rendered...
 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...
 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.
Sunday 26
 This April 26, 2020,
tech-themed crossword puzzle is bigger than most, figuring that unfortunately
many people have more time to kill due to the situation described in the sentence
formed by 5 Down, 8 Down, 44 Down, 74 Down, 77 Down, and 80 Down. Otherwise, it
contains only clues and terms associated with engineering, science, physical, astronomy,
mathematics, chemistry, etc., which I have personally built over nearly two decades.
Many new words and company names have been added that had not even been created
when I started in the year 2002. You will never find a word taxing your knowledge
of a numbnut soap opera star or the name of some obscure village in the Andes mountains.
You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical
location like Tunguska, Russia, for reasons which, if you don't already know, might
surprise you.
 Res-Net Microwave has a complete line of precision
RF & microwave components
including attenuators, terminations, resistors, and diode detectors for commercial,
military, and space applications. Products range from the small flange type to large
2,000 watt connectorized power attenuators and/or terminations at frequencies up
to 26.5 GHz. In-house photo etch and laser trim capability. The company is
a leader in development and production of the films required for these type of RF/microwave
components. Please check out Res-Net Microwave's website to see how they can help
with your current 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. I also
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