Today in Science History -
Here is your custom made
Science Themed Crossword Puzzle for August 7th, 2022. 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 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!
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...
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
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!
As I often do on Fridays, I searched through
my collection of vintage electronics magazines for some
comics. This group of five appeared in the July 1952 issue of Radio-Electronics.
A couple of these were suggested by the magazine's readers, and staff artists turn
the ideas into drawings. The Standing Waves comics gets my vote for the best of
the lot for cleverness. Page 102's comic could be (almost) a depiction of a contemporary
in-home entertainment center, given the size of televisions today. For some reason
I'm not "getting" the gag in the page 113 comic, which features a buxom woman with
big hair doing a juggling act on TV...
I have to admit to being drawn to this story
primarily due to the graphic. Although it does not appear on an RF website, there
is a Smith chart and reflection coefficient equations included. I also like the
striated blue motif. "Multivariable calculus, differential equations, linear algebra
- topics that many MIT students can ace without breaking a sweat - have consistently
machine learning models. The best models have only been able to answer elementary
or high school-level math questions, and they don't always find the correct solutions.
Now, a multidisciplinary team of researchers from MIT and elsewhere, led by Iddo
Drori, a lecturer in the MIT Department of Electrical Engineering and Computer Science
(EECS), has used a neural network model to solve university-level math problems
in a few seconds at a human level. The model also automatically explains solutions
and rapidly generates new problems in university math subjects. When the researchers
showed these machine-generated questions to university students, the students were
unable to tell..."
These are the schematics and parts list
Crosley model 56TD-W vacuum tube radio, as it appeared in the November 1947
issue of Radio News magazine. I scan and post these for the benefit of hobbyists
and historians seeking such information. As time goes by, there is less and less
likelihood that records of these relics from yesteryear's archives will be made
available. As with all historical information, it takes someone with a personal
interest in preserving the memories in order to fulfill the mission, and I am glad
to be a small part of that cadre. Also, I found a short video (below) from someone
who did an excellent job restoring a Crosley Model 56TD Duette tabletop radio...
Atek Midas, based in Istanbul, Turkey, is
a technology company working on high-frequency integrated circuit (RFIC/MMIC) products
as its roadmap. Their main target markets are satellite communication, telecommunications,
test & measurement and aerospace & defense. Atek Midas has been added to
my collection of Vendor pages in the categories
of RFIC/MMIC's, attenuators, power and low noise amplifiers, mixers, power dividers,
filters, RF front ends. Please check out their website to see if they can help you
with your project...
Antenna radiation (beam) patterns published
by manufacturers are obtained under ideal - or close to ideal - conditions with
a carefully prepared and calibrated open air test site (OATS) or an enclosed anechoic
chamber. Multipath, imperfect earth ground, obstacles both manmade and natural,
misshapen elements, poor VSWR, antenna orientation (in both azimuth and elevation)
are among the many factors which produce real-world operational results that do
not jive with a manufacturer's datasheet. Without employing some far field 3-dimensional
field strength scheme (see Drone-Based Field Measurement System™), there is no way
to obtain a complete picture of how your antenna performs in all directions. This
article presents a practical procedure for making measurements that will at least
collect useful data for specific orientations...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
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...
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.
Prior to the invention of the
silicon-controlled rectifier (SCR), most semiconductor devices were only able
to handle powers in milliwatt range, with some reaching into the realm of a few
watts or tens of watts. Voltage handling got up to around 1 kV (and 500 A)
for diodes and 200 V for transistors. The higher power and voltage devices
were exceedingly expensive and were used primarily in special applications. When
this article appeared in a 1966 issue of Electronics World magazine and
the SCR had been introduced less than a decade earlier, the price of an SCR had
dropped from more than $300 to less that 50¢ apiece. Due to the construction of
the SCR, it is more robust and can handle high power switching applications (it
is generally not used as a signal amplifier). Unlike a triac, which can be controlled
with a signal to turn the device both on and off while voltage is present across
the anode and cathode, the SCR can only be used to switch off current...
It's time to gather 'round for another story
about fictional radio service shop owner Mac McGregor and his trusted sidekick technician,
Barney. In this January 1954 Radio & Television News episode, an errantly
wired bypass capacitor on a chassis from one of the old AC/DC radio sets caused
Mac to get a 300-volt wakeup call when his hand brushed against it. After explaining
the situation to Barney and apprising him of the danger it poses to an owner who
unwittingly sticks his/her hand into the back of the cabinet, Mac lists a few other
common dangers to watch for. Radios that ran on either AC or DC power were very
common back in the early days because there were homes and businesses that had both
type systems wired in to the premises - in part due to the famous battle between
Thomas Edison's preferred DC electrical distribution system and Nikola Tesla's preferred
AC electrical distribution system. Another reason for DC compatibility was that
prior to the Rural Electrification Act of 1936, many homes not located in cities
and nearby suburbs had no electric service at all. Farm homes often ran on DC power
supplied by banks of lead-acid storage batteries, with wind- or water-powered generators
providing the charging current. Radios, aka "wireless sets," were powered by those
batteries. In order to accommodate both AC and DC supplies...
"Silicon is one of the most abundant elements
on Earth, and in its pure form the material has become the foundation of much of
modern technology, from solar cells to computer chips. But silicon's properties
as a semiconductor are far from ideal. For one thing, although silicon lets electrons
whizz through its structure easily, it is much less accommodating to "holes" - electrons'
positively charged counterparts - and harnessing both is important for some kinds
of chips. What's more, silicon is not very good at conducting heat, which is why
overheating issues and expensive cooling systems are common in computers. Now, a
team of researchers at MIT, the University of Houston, and other institutions has
carried out experiments showing that a material known as
cubic boron arsenide
overcomes both of these limitations. It provides high mobility to both electrons
and holes, and has excellent thermal conductivity..."
Axiom Test Equipment, Inc., an electronic
test equipment rental and sales company has published a new blog post entitled "Modular
Test Solution Speed Semiconductor Testing," explains how to pick the right module
when you need a solution with semiconductor testing. A well-designed mainframe that
operates according to plug-in modules can not only pack a great deal of measurement
power into a small space, but it can also be configured as needed by exchanging
modules. Modular semiconductor parameter testers are capable of top-line mainframe
accuracy along with the test speed and flexibility for high-volume production-line
device testing. Modular units provide a more "compressed" approach to executing
semiconductor parameter measurements. A modular unit consists...
Achieving what we consider relatively simple
results with electronics indicators used to be cutting edge technology. This
Indicator Tube by Ken-Rad (a division of General Electric) provided a dual-channel
electrofluorescent (i.e., cathode ray) display of relative signal strength or tuning
the new-fangled FM radio stations. It was promoted in this 1947 issue of Radio
News magazine. The tube could also be used, of course, for many other applications
where signal strength from any measured process: fuel level, voltage, temperature,
stock price, phase angle, sound volume, speed, etc., needed to be measured. Today,
we have electrochemical indicators so cheap that they are built into off-the-shelf
batteries at Walmart...
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
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
This is a pretty good
electronics-related detective story. Admittedly, it did not turn out the way
I expected, which is a good thing because the unexpected curve it threw me caused
me to like the adventure even more. The author is Guy Slaughter, but it could have
easily been one of John T. Frye's "Carl & Jerry" techno-adventures. I say
that because (without giving away the ending) the sleuthing "good guy" uses his
electronics communications savvy to solve the crime, the way Carl and Jerry are
famous for doing. The setting is the early 1950s when electronics repair shops were
commonplace and some customers did their best to swindle the proprietors out of
honestly earned money - and sometimes products. Guy Slaughter wrote earlier pieces
featuring Pedro for Radio−Electronics magazine...
In the "Astro Letters" section of the September
2022 issue of Astronomy magazine,
a reader wrote to ask why Planck mass uses units of 10-5 grams, while
the other two Planck-scale constants (length at 10-33 cm and time
at 10-44 s) are many orders of magnitude smaller. Stan Odenwald
responded: "Using only the three natural constants - the speed of light (c=3x108 m/s),
Newton's gravitational constant (G=6.67x10-11 m3/kg s2),
and Planck's constant (h=6.6x10-34 m2 kg/s) - you
can create three 'fundamental scales': length = (hG/c3)½,
time = (hG/c5)½, and mass = (hG/c)½.
But these scales are experimentally inaccessible. Although the Planck mass appears
reachable (i.e., larger than the other quantities), it actually represents an energy
of 1019 gigaelectronvolts crammed into a Planck-scale volume, which cannot
be replaced by humans (yet). By comparison, the Large Hadron Collider at CERN achieves
only 104 GeV in a volume of space 1010 time larger then the
Planck scale." I'd like to be able to answer a question like that!
Except for a few notable examples such as
the incredibly life-like humanoid robots coming from Japan, the overwhelming majority
robots today are either educational tools, special function equipment for performing
highly precise tasks (surgical, exploratory, search & rescue), or part of high
volume production lines. Back in 1940 when this "Telecan" robot debuted and appeared
in National Radio News magazine, people though of robots almost exclusively
as autonomous devices that would some day make life easier for the human race...
or eventually conquer and subdue the human race into slavery. Constraining robots
to the relatively inefficient layout and proportions of homo sapiens, as engineers
have discovered, greatly limits their utility...
Maurizio Di Paolo Emilio has an article
on the EE|Times website entitled ,"Antenna
Design Considerations for 5G Applications," which discusses some of the issues
needed to be addressed for mobile hardware, namely multiple frequency bands and
increased bandwidth. He begins, "A 5G mobile device's antenna design needs specific
consideration to maintain performance. The entire performance is impacted by the
ground plane, the antenna positioning on the board, and other associated components.
The reliability needed by wireless devices is made possible by analyzing and making
corrections from the very beginning of design. In order for smartphones to function
well over a wider variety of RF frequency bands and support the transition to 5G
and other technologies, tuning the aperture of an antenna is crucial..."