Today in Science History -
Lightning has not
changed since the days when Benjamin Franklin flew his special kite during
storms. Contrary to some peoples' belief, he did not "discover electricity;"
rather, the experiment proved his theory that lightning was a form of electrical
discharge. Maybe someone has already pointed this out, but in effect Franklin
put into service the world's first
lightning rod. The conductive (wet with rain) hemp rope between the metal
wire spike on the kite and ground (the plate of a Leyden jar) performed the task
a lightning rod is meant to do - lower the difference of potential between the
charged clouds and ground, thereby reducing the likelihood of an electrical
discharge. An induced current traveled along the rope and charged the Leyden
jar. If lightning had actually struck the kite as fables suggest, Franklin would
probably have been killed even though he was holding on to a silk string
attached to the bottom of the hemp string to provide some insulation.
Mr. Kirchhoff's current law would have apportioned the lightning strike current
at the knot joining the two strings according to the respective...
Uncertain Future of Ham Radio." Now there's a loaded title for an article on
the IEEE Spectrum website. Written by Julianne Pepitone asserts, "Software-defined
radio and cheap hardware are shaking up a hobby long associated with engineering."
There are couple ways to look at the situation. One is that the availability of
pre-engineered and built equipment is harming the fundamentals of the hobby by removing
the requirement for a deeper understanding of the fundamentals. Another is that
the real world of engineering is going the same way as well. Freeing up talent from
the need to create and fabricate every minute aspect of a project opens opportunity
for other creativity and skills building. As a documented lover of vintage equipment,
I am willing to allow for modern approaches for vastly improved technology and,
coincidently, lower prices. Ditto for all hobbies and activities.
"The Senate's annual defense policy bill
would authorize an additional $120M toward a space-based sensor layer capable of
tracking hypersonic weapons, despite the fact the Department of Defense did not
seek more funding for the project in its fiscal 2021 budget requests. The
Hypersonic and Ballistic Tracking Space Sensor is DoD's answer to the growing
threat posed by hypersonic weapons being developed by China and Russia. Hypersonic
weapons present a significant challenge to the United States' current missile warning
architecture. Not only can these weapons maneuver around ground based sensors, they're
too dim to be picked up and tracked by space-based sensors in higher orbits. HBTSS
theoretically solves this problem via a proliferated constellation of Overhead Persistent
Infrared (OPIR) sensors operating in low earth orbit..."
Proper soldering is almost as much of an
art form as it is a technical skill. Having been through numerous soldering classes
in my career, starting with electrical vocational courses in high school, then again
in USAF technical school, and other times while working as a technician and engineer,
I always exercise care in
making solder joints. Proper preparation - including both tinning of mating
surfaces and a means to prevent the joint members from moving during cool-down -
is of utmost importance for assuring a nice, smooth, shiny joint with just the right
amount of solder. Lead-free solders do not tend to produce the level of shininess
as do the good old 60-40 type tin-lead solders, but you can still make a nice looking
joint. This might be more information than you want to know about me, but I even
strive for perfection in solder joints in copper pipes and fittings used in plumbing
Mssrs. G. Kiesel, P. Bowden, K. Cook, M.
Habib, J. Marsh, D. Reid, C. Phillips, and B. Baker of Georgia Tech Research Institute
have an interesting article on the Aerospace Defense website entitled, "Practical
3D Printing of Antennas and RF Electronics." The earliest forms of 3D printing
involved depositing successive layers of a pasty substance on a substrate, with
a curing steps between layers. Next can using a melted polymer (plastic) filament
to lay down tiers without the need for intermittent curing. For many years processes
have been developed for 3D printing metallic structures. Many of these techniques
are being used in "additive manufacturing" schemes to produce marketable items,
including complex 3D shapes needed for medicine, automotive, and aerospace markets.
This article discusses 3D printing in the RF & microwave realm.
Triad RF Systems designs and manufactures
RF power amplifiers and systems.
Triad RF Systems comprises three partners (hence 'Triad')
with over 40 years of accumulated knowledge of what is required to design, manufacture,
market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA,
bi-directional, and frequency translating amplifiers are available, in formats including
tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology
partner than a vendor for our line-of-sight communications product line." Please
check to see how they can help your project.
With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
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...
This week's custom RF Cafe crossword puzzle
contains some words particular to amateur radio, along with other tech-themed words
and clues. Each week for two decades I have created a new
technology-themed crossword puzzle using only words (1,000s of them) from my
custom-created lexicon related to engineering, science, mathematics, chemistry,
physics, astronomy, etc. You will never find among the words names of politicians,
mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You
might, however, find someone or something in the otherwise excluded list directly
related to this puzzle's technology theme, such as Hedy Lamarr or the Bikini Atoll,
respectively. Avid cruciverbalists amongst us: the gauntlet has been thrown down...
When looking a these
electronics-themed comics, it probably is a case of "you had to have been there"
to appreciate the humor in them. In a world of 24/7 broadcasting of every TV channel,
the first comic wouldn't even make sense to someone who was born after about 1990,
after which time most local over-the-air broadcast stations signed off at 1:00 or
so, played the National Anthem, and then displayed a test pattern until about 6:00
am. The second comic is from the era of high voltages inside radio and TV chassis
for vacuum tube plates and CRT accelerator grids. That big bulky thing the guy in
the last comic is carrying is a thing called a cathode ray tube (CRT), which old
people used to use to view television shows and SVGA computer displays...
RF Diagnostics, LLC, designs and sells surface
mount RF to DC converters and other building block modules for
RF energy harvesting systems. With our products you can harvest ambient AC/AM/FM/Wireless
Energy to power your IoT battery-free system. For example, the RFDKIT−01 RF Energy
Harvesting Experimenter Kit is intended for energy harvesting developers and hobbyists.
It is intended for low power system developers and hobbyists. The kit contains parts
to collect and manage the power from wireless energy from 1 Hz to 6 GHz.
Users can connect to the modules using the included 4-pin headers with a little
soldering and clipping. We also provide custom designs for RF/microwave and general
electrical engineering products and design contracting services to clients in the
commercial wireless and defense electronics businesses...
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
"A transistorized i.f. stage for a TV set
can be built today to fit into a match box. But
molecular electronics has made possible the production of a device that contains
two such stages and is only a fraction of the size of a single transistor!" Nobody
talks of molecular electronics today, but that really is an accurate term for what
we have when compound semiconductors like GaAs, GaN, or any of the many-atomed exotic
photovoltaic substrates are being discussed. When referring to pure elements like
silicon that are being doped with impurities, I'm not sure those structures are
considered molecules which, according to Dictionary.com, are "the smallest physical
unit of an element or compound, consisting of one or more like atoms in an element
and two or more different atoms in a compound..."
Empower RF Systems'
Model 2225 is a long duty cycle pulsed amplifier operating from 5.2 to
5.9 GHz and represents our new technologically advanced liquid cooled and scalable
architecture. This breakthrough solid state GaN design replaces tube technology
to bring new capabilities to EW, Radar, Directed Energy and Satcom applications
where tens and hundreds of kilowatts of CW and Pulse power are required. This new
modern architecture offers scalability for affordable upgrade paths to future power
needs by adding hardware to an existing system. Additional racks can be combined
and for racks not fully populated, 2U amplifier drawers can be added without the
need for tuning...
Please take a few moments to visit the
everythingRF website to see how they can assist you with your
project. everythingRF is a product discovery platform for RF and microwave products
and services. They currently have 267,269 products from more than 1397 companies
across 314 categories in their database and enable engineers to search for them
using their customized parametric search tool. Amplifiers, test equipment, power
couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Radio & Television News editor
Oliver Reed wrote in this 1955 issue about the "flattening" of electronics - including
both individual components and overall assembled products. He described a large
screen, wall-mountable television system with built-in flat stereo electrostatic
speakers. "The so-called 'picture
on the wall' television screen has also received widespread publicity although
such a screen is not yet commercially available. In this system, a flat screen is
connected to the TV receiver by means of a cable, and the picture is formed on the
screen electronically." That is a lot like a large flat LCD or LED monitor being
fed by an HDMI cable from a computer. Mr. Reed also writes of a magnetic tape
video playback system akin to what eventually became the VHS / VCR. Evidently the
concept of an optical-based storage medium like the DVD and Blu-ray disk was too
far out of the realm of possibility...
Anatech Electronics has a handy app note
describing how to
select and specify coaxial cables and assemblies. "Coaxial cables
are too often taken for granted and RF and microwave systems. As a result, they
are often treated like a spool of bell wire, twisted, band, crimped, stepped on,
and subject to assorted other abuses. However, the more you know about coaxial cable
the more likely you are to treat it with respect, as its integrity, lifetime, and
overall performance are at stake. To get a better understanding of coaxial cables
in general, Anatech Electronics has prepared a series of guides that provide information
about RF and microwave coaxial cables ranging from the basics contained in this
application note to more detailed information about characteristics, applications,
specific cable types, and other topics..."
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...
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.
"Do you think that F.C.C. would be engaged
in the present terrific expense and effort of getting our fingerprints and citizenship
histories if there were intention of shutting us down shortly?" That statement was
printed by the QST magazine editor in the issue that preceded the December
7, 1941, attack on Pearl Harbor by thirteen months. A few things about it are troubling.
FCC was collecting
fingerprints of licensed amateur radio operators. Second, the FCC was assimilating
information about licensed amateur radio operators' citizenship histories. Third,
a combination of short-sightedness and apparent naiveté concerning the FCC's willingness
to shut down amateur radio operations once America had been inevitably drawn into
World War II...