Thursday 31
There's no denying that 2020 has been one
of the worst years in a long time. The Wuhan Virus is responsible for more deaths
in America than the September 11, 2001 terrorist attacks, and has crippled nearly
the entire world medically, psychologically, and financially. Overzealous government
officials have gotten away with imposing restrictions on personal freedoms beyond
anyone's imaginations. With few exceptions, we all are required to wear facemasks
that are practically useless in public, and are forced to isolate from our fellow
human beings with the threat of fines and imprisonment for non-compliance. Self-appointed
busybodies have appeared to tongue-lash anyone not fitting their idea of a fully
state-compliant citizen. Although it will not erase the darker moments of 2020,
hopefully this handful of
electronics-themed comics from a 1941 issue of Radio News magazine
will help take the edge off. Here's hoping 2021 will be a better year!
Yay for us. Our
pollution production levels
are way down compared to what they were in the middle of the last century. Seriously,
things were getting really bad. Pittsburgh was considered such a hopeless mess that
famed architect Frank Lloyd Wright, whose landmark Fallingwater home sat nearby,
when asked what to do about Pittsburg's terrible pollution responded, "Abandon it."
Lake Erie had been declared officially dead. Love Canal dominated headlines. Los
Angeles air was (and still is, BTW) unbreathable. After huge public awareness campaigns,
cleanup efforts, and stricter enforcement of pollution laws, the trend halted and
has reversed. That is unquestionably good news. The bad news is that as pollution
control got better, companies found continuing manufacturing operations in the U.S.
was unprofitable based on what people were willing to pay for their products. Steel,
the literal and figurative backbone of industry, could not be mined, smelted, and
processed into finished goods at a price that would encourage innovation and growth...
"Researchers have developed a
novel design approach that improves upon limitations of conventional antennas
operating at low frequencies, demonstrating smaller antennas that maintain performance.
Impedance matching is a key aspect of antenna design, ensuring that the radio transmits
power through the antenna with minimal reflections while in transmit mode and that
when the antenna is in receive mode, it captures power to efficiently couple to
the radio over all frequencies within the operational bandwidth. Impedance matching
techniques with passive components..."
Comic strips used to be a popular venue for
instruction as well as for humor. Early editions of QST and many other
magazines often had many small comics scattered throughout. The one featured here
came from the May 1941 QST. Amateurs were and still are a vital part of
disaster response efforts. In fact it is pretty much inarguable that a big part
of why the FCC has not stripped away a larger portion of the allocated Ham bands
is due to the thousands of operators who volunteer their time and equipment to assist
government and private agencies with communications during times of duress. Some
have argued that the "amateurs" often do a much better job at disseminating time-critical
information that the "professionals."
PCBONLINE, a one-stop custom PCB/PCBA manufacturer
for prototypes, has posted a blog that answers the question, "What's
going on in testing the printed circuit board assembly?" Unlike most PCB assemblers,
the advanced PCB manufacturer PCBONLINE can process functional tests before delivery
so that our clients don't have to test on their own. PCBA testing at PCBONLINE includes
the Automated Optical Inspection (AOI) test during the assembly process, functional
test, and thermal aging test after the assembly. During the AOI and functional test,
if the PCBA is good, the computer screen will display OK. Otherwise, it will display
NG (no good), and all test process data can be recorded. The aging test consists
of powering on the PCBA to let it work for some time depending on the product application.
If the indicator light is on, the PCBA test is good...
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.
Wednesday 30
Do you remember back in the 1980s when adoption
of the IEEE−type logic schematic symbols* got a big push? It proposed a logical
approach (pun intended) to building any type of combinational logic or sequential
logic devices based on strict rules of construction. Curved lines are nowhere in
sight. Interestingly, the same type of schematic symbol "simplification" was proposed
in the 1940s. The motivation for removing curved lines was to prevent draftsmen
from needing to use a compass or special drawing template rather than using only
a straight edge. Vacuum tube outlines, light bulbs, inductors, etc., required more
time to pencil in. In 1944, this article entitled "Are
Radio Symbols Wrong?" appeared in Radio-Craft magazine...
PCB Directory is the largest directory of
Printed Circuit Board (PCB) Manufacturers,
Assembly houses, and Design Services on the Internet. We have listed the leading
printed circuit board manufacturers around the world and made them searchable by
their capabilities - Number of laminates used, Board thicknesses supported, Number
of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
"An especially counter-intuitive feature
of quantum mechanics is that a single event can exist in a
state of superposition
- happening both here and there, or both today and tomorrow. Such superpositions
are hard to create, as they are destroyed if any kind of information about the place
and time of the event leaks into the surrounding - and even if nobody actually records
this information. But when superpositions do occur, they lead to observations that
are very different from that of classical physics, raising questions that spill
over into our very understanding of space and time. Scientists from EPFL, MIT, and
CEA Saclay, publishing in Science Advances, demonstrate a state of vibration that
exists simultaneously at two different times..."
In 2012, we were inundated with stories on
the 100-year anniversary of the "unsinkable" RMS Titanic, on April 15, 1912. Even
after a century of research and exploration, no definitive cause has been determined
relating to how the ship's crew managed to hit a gigantic iceberg on a star-lit,
glass-smooth sea. The prevailing theory seems to be that an optical illusion due
to an atmospheric inversion caused the crew to misjudge the position of the iceberg.
An article in the March 2012 Smithsonian magazine lays out the scenario,
complete with diagrams. The same edition has a story titled, "They Missed the Boat,"
discussing some of the famous people who were originally scheduled to make the voyage,
but decided not to before it departed. Amongst the notables was none other than
1909 Nobel Prize in Physics honoree
Guglielmo
Marconi. Instead, he left for America on the Lusitania three days earlier. Interestingly,
he also made the Atlantic passage on the Lusitania three years later on the trip
immediately before a German U-Boat sunk it...
RF Cascade Workbook 2018 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...
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."
Tuesday 29
It's probably a safe bet that most people,
even at the
dawn of color television, knew of the competition which occurred for the adoption
of three different methods of implementation. Two of them - line-sequential by Color
Television, Inc. (CTI), and dot-sequential by Radio Corporation of America (RCA)
- were fully electronic while the third system by the Columbia Broadcast System
(CBS) used a kludge of a spinning color wheel placed in front of a black and white
display. The CBS field-sequential design used a synchronization component of the
composite transmitted signal to position the correct color screen (red, yellow,
or blue) in front of the screen as the electron gun scanned the CRT - analogous
to how World War I airplane machine guns were synchronized with the engine
to fire between propeller blades. Of course an out-of-synch scenario in the color
wheel was not as serious as with the machine gun. The worst that could happen with
the TV is a false color picture whereas with the machine gun your biplane instantly
became a glider. Although I poke some fun at the CBS solution...
"Conventional fiber optics guide light through
solid glass cores that are extremely transparent. The clearest fibers have loss
as low as 0.142 decibel per kilometer. Which means that more than one percent of
input light remains after a hundred kilometers. Yet solid glass fibers cannot carry
very high powers, particularly in short pulses, limiting their use for applications
including delivering intense light for laser machining. Now a team at the University
of Southampton's Optoelectronics Research Center has made
hollow-core fibers that are clearer than solid-core fibers at some important
wavelengths. They report their results in Nature Communications..."
Withwave's
New Compact N-Type Calibration Kit offers excellent performance characteristics
that is specially designed for fine-tuning in production environments and quality
testing facilities using N-type connectors from DC to 8 GHz. This Calibration Kit
includes all needed calibration standard (Open, Short, Load) in one unit. It is
the best solution available for ease of use in VNA calibration, especially in the
field. Return loss (Load): <-42 dB for DC to 6 GHz, <-38 dB
for 6 to 8 GHz...
For many years I have been scanning and posting
Radio Service Data Sheets for sets like this
Westinghouse Model WR 207 & WR 208 5-tube dual-band superheterodyne tabletop
radio model. Hundreds of them appeared in magazines like Radio-Craft and Radio News
from the 1910's up until around the 1960's. This one appeared in a 1936 issue. There
were a couple companies (Sams Photofact, most notably) that sold packages of service
data for all new domestic use electronics products, but smaller service shops could
not easily afford the subscription cost, and the do-it-yourselfer was out of luck
because the manufacturers did not sell such data to non-licensed dealers. Today
it is even harder to come by the information. Often, images of these radios can
be found on websites like RadioMuseum.org and RadioAttic.com. Another great source
is eBay, but usually those are not as photogenic because they are in need of restoration...
"Cambridge Consultants, part of Capgemini,
revealed its role in a visionary program to realize the dream of
superfast 5G for everyone and everything across the globe. Working in collaboration
with Stratospheric Platforms Limited (SPL), Cambridge Consultants achieved a remarkable
technical feat with a wireless antenna unlike anything seen before, delivering affordable
connectivity from a fleet of zero emissions aircraft, airborne at an altitude of
20,000 meters for more than a week. Operating at a fraction of the cost of building
and maintaining terrestrial infrastructure, and with minimal environmental impact
due to its zero-emission hydrogen power system, such a fleet could rewrite..."
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