Today in Science History -
Frequent RF Cafe visitor who goes by the
moniker "Unknown Engineer" sent me a hyperlink to a PDF file on Amazon's CloudFront*
content delivery network (CDN - basically a file server) that contains no fewer
than 17 amazing radar and vacuum tube related line
drawings published by Varian Associates' TWT Division, Palo Alto Tube Division,
Solid State Division, Eastern Tube Division, Western Tube Division, Solid State
West Division. These highly detailed and busy drawings were done around 1975 by
British illustrator/artist C.E.B. Bernard; a search for his works did not reveal
much. The events shown are fictitious, as are the accompanying hand-printed stories.
Some of the puns are pretty clever, but are somewhat dated for today's readers.
To wit, the name Memamadun Ptolemy, which for the uninitiated is an allusion to
the movie "Blues in the Night," where the actual words are "My momma done 'tol me..."
(get it?). Another worthy mention is, "Tube V or not Tube V, that is the question,"
an obvious play on Shakespeare's "To be or not to be, that is the question" line
by Prince Hamlet. If you recognize those, you'll find other familiar takeoffs as
"The life-givers of
integrated circuits and quantum devices in silicon are small structures made
from patches of foreign atoms called dopants. The dopant structures provide charge
carriers that flow through the components of the circuit, giving the components
their ability to function. These days the dopant structures are only a few atoms
across and so need to be made in precise locations within a circuit and have very
well-defined electrical properties. At present manufacturers find it hard to tell
in a non-destructive way whether they have made their devices according to these
strict requirements. A new imaging paradigm promises to change all that. The imaging
mode called broadband electric force microscopy..."
When I think back at the
labs from my days in school, I wonder how much things have really changed from
then until now. It is hard to believe that freshman and sophomore labs are not still
consumed with radial lead resistors, inductors, and capacitors, solderless breadboards,
and a variety of light bulbs, motors, transformers, relays, and rheostats. By the
time you move into the junior year, labs have gotten a bit more intense with microprocessor
controls (mine used an 8088 CPU with machine language programming for the serial
port), some high voltage apparati[sic], digital logic circuits, and a chance to
lay out/fabricate/populate a PCB. On-hand test equipment consists of 2nd or 3rd
generation oscilloscopes, signal generators, and power supplies. I did a search
for photos of labs from back in the early to mid 1900s to see if much had changed
from then until the time I was in college...
On July 28, 2020, Apple was granted patent
number US10727570 entitled "Electronic
devices having antennas that radiate through a display." Abstract: "An electronic
device may be provided with a display and a phased array antenna that transmits
radio-frequency signals at frequencies greater than 10 GHz. The display may
include a conductive layer that is used to form pixel circuitry and/or touch sensor
electrodes. A filter may be formed from conductive structures within the conductive
layer. The conductive structures may include an array of conductive patches separated
by slots or may include conductive paths that define an array of slots. The filter
may include an additional array of conductive patches stacked under the array of
conductive patches to allow the slots to be narrower than would be resolvable to
the unaided human eye. The periodicity of the conductive structures and the slots...
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
supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies,
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We're leading the way again!
Heathkit's claim to fame was that it was
able to offer user-assembled kits of high quality electronic products at a price
lower than what equivalent factory assembled equivalents would cost. While that
is probably generally the case, it is difficult to gauge what the relative quality
really is. Some of the kits were easy to assemble for even people with little experience,
but a good portion of them required familiarity with soldering and how electronics
were put together. The instructions provided were very thorough, complete with photos
and drawings of how each step should look. In fact, according to a 1972 installment
of Mac's Service Shop entitled "Philosophy of a Kit Manufacturer," every Heathkit
kit instruction booklet goes through a rigorous cycle of writing, testing, and rewriting
before being released for production...
Axiom Test Equipment, an electronic test
equipment rental and sales company has published a new blog post entitled "Practical
Solutions for Measuring Phase Noise" that examines phase noise, what it is,
why too much noise and frequency instability can be a problem in testing, and how
to find the right method and equipment for measuring it. Phase noise can often be
measured directly using different measurement approaches such as residual and cross-correlation
techniques, which are explored more in-depth in the blog. Most importantly, the
blog explains what specifications to look for in a spectrum or signal analyzer to
ensure the best fit for the job. A few equipment examples are given as guides...
"Scientists said they had discovered a way
detect space debris even in daylight hours, potentially helping satellites to
avoid the ever-growing cloud of junk orbiting the planet. Defunct rockets, satellites
and spacecraft parts continue to orbit Earth after they are discarded. The estimated
500,000 objects circling the globe range in size from a single screw to an entire
rocket fuel tank. Travelling at thousands of miles an hour, they pose a huge and
rising collision risk to satellites. Using lasers, it is possible to detect the
debris from the ground..."
One very satisfying aspect of 'rolling your
audio frequency coils (aka chokes, aka inductors), is how well the simple inductance
equations match measured end results. Unless you really manage to mangle the job,
if you use the right equation and are reasonably careful to observe wire size, spacing
(including insulation), and core diameter, you will be amazed at how close practice
matches theory. Although strictly speaking audio frequencies run from a few Hertz
up to maybe 15 kHz for people with really good hearing. My experience is that
similar success can be had even into the low MHz realm with just a little tuning
required. It's not until you get into the realm of self-resonance that everything
starts falling apart...
Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. The P/N AE1200-1400DB5450
passes DC-1200 MHz and 1400-3000 MHz with a crossover insertion loss of
5 dB at 1300 MHz crossover frequency at 1300 MHz and in band insertion
loss of less than 1 dB. The AE2310B11640 passes the LTE band of 2305-2315 MHz
with an in-band insertion loss of less than 1 dB. The 2305-2315 MHz bandpass
filter exhibit a very sharp transition to the rejection band with a power...
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.
An engineer friend wrote saying he is in immediate need of 50 pieces
of the Cree
CMPA0060025F, 25 W, 20-6000 MHz, GaN MMIC power amplifier. If you
can supply any quantity, please contact me at firstname.lastname@example.org
to let me know. Time is of the essence. Thank you very much!
Crossword" appeared in the September 1958 issue of Radio & TV News magazine.
Its creator, John Gill, designed specialty theme crossword puzzles for many other
editions of Radio & TV News and Electronics World (see the big list at the bottom
of the page). He considered this crossword to be a "fooler" because he claims
to include many "unusual definitions and a number of obscure words which you will
have to work around if your vocabulary of 'exotic words' is rusty." It really doesn't
seem so difficult to me, and anyone used to working my custom RF Cafe Crosswords
will have no problem with it.
To meet the challenging requirements of cellular
LTE and 5G NR infrastructure applications, Skyworks has released the
SKY67183−396LF and SKY67189−396LF low noise amplifiers (LNAs). These LNAs feature
ultra low-noise figure, exceptional linearity, and operate over a wide range of
frequencies. To reduce PCB board space, these devices are housed in an ultra-compact
2 x 2 mm plastic surface mount package. The SKY67183−396LF and SKY67189−396LF are
ideal for 2G/3G/4G/5G TDD and FDD infrastructure applications, including small cell,
massive MIMO, and macro base...
"After completing a countdown dress rehearsal,
Astra is gearing up for its first orbital launch attempt this week from Kodiak Island,
Alaska, but company officials said it will likely take multiple test flights before
small satellite launcher successfully reaches orbit. Astra's small satellite
delivery vehicle was set for liftoff from the Pacific Spaceport Complex in Alaska
during a two-hour window opening at 10 p.m. EDT Sunday, or 6 p.m. local time in
Alaska. In social media updates, Astra said it fueled the small satellite launcher
with liquid propellants Sunday. But officials said out-of-limits upper level winds
and a boat in restricted waters offshore..."
When someone with the first name of "True"
writes an article about transmission line feeds for short-wave antennas, you should
probably take note. This very topic has been covered in detail many times since
the use of impedance-matched transmission lines have been in use (more than a century),
but since there are always people new to the concept, it is good to keep introducing
the topic on a regular basis."Transmission-Line
Feed for Short-Wave Antennas" appeared in a 1932 issue of QST magazine.
Even in this era of prefabricated everything, it still often comes down to winding
coils and adjusting cable lengths to get optimal impedance matches between transceivers
I have extolled the virtues of Aerospace &
Defense Technology magazine many times for its variety of extremely interesting
articles on a wide range of topics. The August issue has a story on the
element Vanadium (atomic number
23) and the critical role it
plays as an alloy component of metals. At concentrations of less then 0.1%, vanadium
can nearly double the strength of steel and aluminum, as well as increasing resistance
to corrosion. It is also used as a catalyst (sometimes a substitution for nickel
and platinum), in electronics components, and in ceramics. Use of vanadium is considered
"green" because most of it is obtained from byproducts of other industrial processes
like ash from coal burning. Vanadium is the earth's 22nd most abundant element and
is found everywhere, but as you might suspect China provides 61% of the supply while
the U.S. does a mere 3% (Russia makes 14%). Fortunately, part of the Dept. of Interior's
2018 charter was to include vanadium on its list of critical commodities and must
act to significantly increase domestic production rather than be dependent on foreign
sources. It's long past time.
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