 Friday the 8th
Thursday the 7th
Wednesday the 6th
Tuesday the 5th
Monday the 4th
Sunday the 3rd
 In these times of communists and Marxists
(and other "-ists") infiltrating high positions of American government and destroying
our hard-won legacy of freedom, compassion, traditional family values, hard work,
and patriotism, this
Independence
Day theme crossword puzzle is created to celebrate our heritage and resist the
corrupters. The Cancel Culture mobs will never dissuade our staff (Melanie and me)
here at RF Cafe! Clues with an asterisk (*) are related to the puzzle's theme. All
crossword puzzles use a personally built dictionary of thousands of 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...
 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."
Friday the 1st
 Life is a constant battle on all fronts,
be it in health, personal relationships, business, medicine, careers, education,
technology, or any other realm. Scientists, engineers, and technicians at the former
Bell Telephone Laboratories are affected by that maxim as well as any group
of people. The company, known to many as Bell Labs, invested a huge amount of funds
and personnel effort into fighting the problems while constantly cropped up both
during research and development and which servicing their massive installed base
of equipment and transmission lines. Bell Labs regularly ran full-page ads in magazines
(including technical and others like Life, The Saturday Evening Post, Woman's Day,
etc.) informing the paying public of the extents they went to in order to bring
new products to market and to keep existing systems providing excellent quality
communications (the best in the world). This example for a 1948 issue of Radio News
magazine tells of the unexpected chemistry issues solved by their crack teams of
employees...
 Center of Telecommunication Technologies
(CTT) is proud to announce immediate availability of its
Indoor
RadioPlanner v1.0 software. Indoor RadioPlanner is a planning tool for Wi-Fi
and other indoor wireless networks. Release 1.0 is mainly intended for planning
Wi-Fi networks in the 2.4 GHz, 5 GHz, and 6 GHz bands, but it can
be used for planning indoor GSM/ 3G / LTE / 5G networks in the frequency range 300 MHz
– 7.5 GHz. With Indoor RadioPlanner, you can design Wi-Fi networks of any scale
- from a small office to a large multi-story building...
 Berkeley Nucleonics recently added a couple
of courses on
Quantum Computing in the Berkeley Nucleonics Academy. Because you have taken
previous RF courses with 100% completion, you are entitled to those QC courses at
no charge. Would you like a passcode? You may also share this code with any colleagues
or students who may have an interest. Completion of the course takes approximately
4 hours and includes CEU units, a Completion Certificate and a BNC "60 Years" Commemorative
Tee-Shirt. The Nuts and Bolts (and Qubits) of Quantum Computing: This exclusive
course will dive into the immersive world of quantum computing. Take quizzes, watch
videos and get current knowledge of quantum computing from experts in the industry.
QC 02 - Quantum Computing Instrumentation in Use Today" A cursory look at some of
the research and development tools...
 Selenium rectifiers were the first widely
used replacements for vacuum tubes in commercial electronic equipment. Since amplification
was not possible - that came in late 1948 with the invention of the transistor,
compliments of Shockley, Brattain and Bardeen - diode action in AC-DC power supplies
was its primary application. Typical reverse breakdown voltage is in the neighborhood
of 20 volts and current handling capability depends on the interface surface area.
Cost kept the selenium rectifiers from being widely adapted early in their history
(1933), but by 1946 when this article was published in Radio-News magazine
it had dropped enough to make their use economical. Eliminating one or two vacuum
tubes in a radio or television power supply made the sets more efficient and increased
reliability since the selenium rectifiers rarely suffered failures if designed into
the circuit correctly...
 Amentum is seeking a motivated
Junior RF Engineer
in Hanover, MD, willing to dive into the world of satellite communication coordination.
Job Summary: We are looking for an engineer with the curiosity to work problems
until truly understood and then the drive to identify and implement efficiencies
in the problem-solving process. You have a foundation in radio frequency (RF) engineer
principles to apply that knowledge in the RF analysis of new and existing satellite
systems being proposed. Responsibilities will include analysis and certification
for emerging spectrum dependent technologies, review of new satellite network submissions,
and evaluation of RF related interactions between satellites. Beyond the analytical,
you'll also need to communicate highly technical findings to a large international
stake holder community. You will be part of a team evaluating the risk to Department
of Defense (DoD) assets...
 Well I'll be darned, old Mac the master
radio repairman taught me something else new in this October 1949 issue of Radio &
Television News magazine. Along with giving sidekick and trusted technician
Barney a lesson on business ethics and how honest dealing can pay dividends as societal
conditions change, he also put on his Sherlock Holmes cap and deduced a
surprising cause for circuit failure based on the physical location of a lady's
radio; read on to learn the details. As usual, the exact scenarios of the stories
do not apply to today's environment and/or equipment, but the troubleshooting logic
certainly does. And, as usual, the time of year wherein the technodrama takes place
aligns with the edition's month of publication...
 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.
 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.
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 You are taught early in your electronics
career to be mindful of the tendency for
measurement equipment to affect the circuit it is measuring, and therefore the
indicated results. In the case of high frequency circuits, even minute amounts of
capacitance and/or inductance can render results utterly unusable, but even in circuits
operating down to D.C. the simple internal resistance of a meter can profoundly
affect measurement accuracy. High impedance circuits are particularly vulnerable
to such "loading" effects by test equipment. For example, consider a circuit being
measured (device under test, aka DUT) that has an impedance of 10 kΩ and the
internal resistance of the VOM is 100 kΩ (see diagram to left). If the open
circuit "true" voltage level is 11 V, then voltage division effected by the
100 kΩ meter in series with the DUT's 10 kΩ internal resistance would
produce a VOM reading of 10 V (ten elevenths of 11 volts) - clearly incorrect.
In the days before FET (field effect transistor) input multimeters, when most volt-ohm-milliammeters
(VOMs) consisted...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to present
the new
Exodus AMP2140C-1LC, a powerhouse in a compact configuration! Covering 2.5-7.5 GHz,
produces 900 W minimum, >1 kW typical output. Excellent gain flatness
with a minimum power gain of 60 dB. Included are amplifier monitoring parameters
for Forward/Reflected power in dBm & watts, VSWR, as well as voltage, current &
temperature sensing for optimum reliability & ruggedness. Unprecedented 32U
panel-space rack integrated. Features include a rack mounted cabinet system, Class
A/AB advanced technology high power linear design, instantaneous ultra-wide bandwidth
designed for EMI/RFI, lab, and general communication applications, suitable for
linear CW and composite signal channel modulation standards & applications...
 Hams like members of the Mogollon Rim
Collins Collectors Club (K0CXX)*, play an important role in the preservation of
vintage radio equipment. They own a nice example of a
Collins model 30K-5 medium
power (250 W) AM transmitter that is the subject of this 1946
article in Radio News. At 5½ feet tall and weighing 350 pounds, the 30K is many
times the volume and weight of a modern solid state transmitter (transceiver +
PA) having the same capability. Its advertised price in 1946 was $1,450, which
is equivalent to $19.9k in 2022 money - obviously not in the affordability range
of your typical amateur radio enthusiast...
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 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...
 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...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Symbols are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
 RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 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...
|
 "Machine learning models
are growing exponentially larger. At the same time, they require exponentially more
energy to train, so that they can accurately process images or text or video. As
the AI community grapples with its environmental impact, some conferences now ask
paper submitters to include information on CO2 emissions. New research offers a
more accurate method for calculating those emissions. It also compares factors that
affect them, and tests two methods for reducing them. Several software packages
estimate the carbon emissions of AI workloads. Recently a team at Université Paris-Saclay
tested a group of these tools to see if they were reliable. 'And they're not reliable
in all contexts,' says Anne-Laure Ligozat, a co-author of that study who was not
involved in the new work. The new approach differs in two respects, says Jesse Dodge,
a research scientist at the Allen Institute for AI and the lead author of the new
paper, which he presented last week at the ACM Conference on Fairness, Accountability,
and Transparency (FAccT)..."
 "Mind-controlled 'metasurfaces' could be
used in health monitoring, 5G/6G communications and smart sensors, according to
Chinese researchers. Mind-controlled 'metasurfaces' could be used in health monitoring,
5G/6G communications and smart sensors, according to Chinese researchers. Chinese
researchers say they have made it possible for
humans to beam radio waves with their brains in a breakthrough that could have
uses ranging from health monitoring to mind-controlled military radar. In an air
force laboratory experiment, researchers showed that brainwaves could control and
interact with electromagnetic waves remotely. 'Our design provides users with a
universal way to manipulate electromagnetic waves using brainwaves,' said Professor
Wang Jiafu, leading project scientist with Air Force Engineering University in northwestern
Shaanxi province..."
 "The invention of the transistor by Bell
Laboratory in 1947 ushered in an era of electronic devices that were smaller and
ran cooler using far less power than their bulky and fragile vacuum tube counterparts.
Transistors function as a binary switch to facilitate electrical current from off
to on states. Radios, calculators and telephones were among the first wave of instruments
to replace vacuum tubes with the new semiconductor technology. As the technology
scaled smaller and smaller, subsequent decades saw the steady integration of silicon
transistors into devices, and today's computers, cell phones, watches, pacemakers,
and virtually every kind of electronic device relies on them for high-speed processing
and memory. Enter the
memristor, an electronic device that emulates the binary switch using a two-
and also three-dimensional matrix configuration, or cross bar array, to regulate
states of conductivity based on current resistance..."
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