|
 World War II was the "necessity" that
elicited the "mother of invention" activity responsible for many huge leaps in technology
- not the least of which was electronic verbal and non-verbal communications. Along
with radio and radar, Loran had become a major means of ocean and air navigation.
A fair description of the operational details, including timing diagrams, is included
in the text. Loran-A, the original system as it came to be known, was fully decommissioned
in 1980, thereafter supplanted by
Loran-C. With the advent of GPS, Galileo, and Glonass navigation
systems and their low and their low equipment and installation costs...
 In this 1960 Popular Electronics
magazine adventure, teenage inventors / hobbyists Carl and Jerry explore the mechanics
of
Space Inertial Reference Equipment (SPIRE), a sophisticated navigation system
using gyroscopes, pendulums, and clocks to track position autonomously. Inspired
by a television program featuring Dr. Charles S. Draper, Jerry demonstrates how
a gyro-stabilized platform maintains spatial orientation regardless of external
movement. The duo soon applies this scientific knowledge to a practical mystery
when a local factory manager seeks their help in catching an employee stealing expensive
alternators. By placing a timer-controlled, battery-operated gyroscope inside a
bait package, they successfully trap the thief. As the culprit exits the factory,
the activated gyroscope creates unexpected torque during a turn, causing the lunch
box to move erratically and reveal the stolen goods. The story concludes with the
boys reclaiming their device, leaving the factory manager delighted by his opportunity
to experiment with the powerful "toy." This plot is a lot like "The Hot Hot Meter"
story.
 This week's
Microwave and RF Engineering crossword puzzle contains the usual
collection of science, math, and engineering terms. Each week for more than 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.
 "Researchers based in Singapore and Belgium
have reported record high peak power-added efficiency (PAE), of more than 60%, for
moderately scaled gallium nitride (GaN) on silicon (Si) high-electron-mobility transistors
(HEMTs) at 30 GHz operation. At the same time, the devices perform with state-of-the-art
noise figures (NFs) as low as 1.1 dB. 'These results suggest that moderate
scaling could deliver competitive
GaN-on-Si HEMT technology, when combined with optimized epitaxial structure
and process..."
 Designing resistive
impedance-matched signal splitting networks is nowadays mostly
done with the assistance of computer software. In fact, odds are pretty high that
the designer either has no idea what the formulas behind the "magic" are, or at
least it has been a very long time since working them with pencil and paper. There's
no shame in that, though, just as there is no reason to expect someone using a cellphone
must know the intricacies of the internal circuits or the network to which it is
connected. We've moved past that. For those of us who still appreciate a refresher
on the behind-the-scenes calculations being performed at lightning speed...
 During and immediately following World War II,
the "Monitoring Service" of the British Broadcasting Corporation (BBC) relentlessly
listened to radio broadcasts from all over the world in order to be able to break
headline news and, if appropriate, pass strategic military information on to Allied
command centers (who were simultaneously doing their own monitoring). This article
tells of some of the more significant messages intercepted and how the facility
was a highly guarded secret in order to prevent sabotage and infiltration. At the
height of activity, 32 languages were being transcribed into English daily, consisting
of more than...
 We have all known at least one of these
guys in our lives. Truth is, some of us - myself included - might have been considered
to be one (or more) of these guys by someone else at some time. Carl Kohler produced
these kinds of comic/real-life pieces for Popular Electronics magazine
for many years. They usually featured a
technohobbyist husband frustrating his mostly-accommodating wife (aka "wife-friend")
with wild-haired inventions and projects. I am always open to someone else offering
an idea or opinion, so long as it is not delivered in an obnoxious manner. On more
than one occasion, a person without even specific technical knowledge will toss
out a great idea that had not occurred...
 OK, I admit that this week's
crossword puzzle is a little self-serving and self-promoting,
but what the hey. All of the clues with an asterisk (*) after them are categories
in the table of contents at the tops of RF Cafe website pages, so that should help
a bit. To make it even easier, they are all on the "Main" TOC menu. 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.,
Hedy
Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst
us will appreciate the effort. Enjoy!
 "Most 3D printers are designed to produce
plastic parts, such as prototypes, housings for electronics, or decorative objects.
Building a working electric machine is far more complicated. Unlike a typical plastic
print, devices like motors need different regions to do different jobs: some conduct
electricity, others insulate it, some generate or guide magnetic fields, and others
provide structural support or flexibility. In a paper published last month in Virtual
and Physical Prototyping, the [MIT] group introduced a
multimaterial 3D-printing
system capable of producing a working electric linear motor in about three hours.
The platform processes five functional materials used in the printed motor..."
 Game playing with a remote opponent is routine
these days thanks to the Internet, but a couple decades ago it was not quite so
easy. A
checkers or chess match via telephone, snail mail, or even fax machine were
the venues available to the common man, but Hams had another means - radio! Using
either Morse code or voice and a playing board set up like the one shown in this
article, two players could easily match wits anywhere in the world where signals
could be exchanged. Evidently the participants could get so wrapped up in the game
that they risked forgetting to broadcast their call signs at the legally required
interval (every 10 minutes), so author Utterback provides a friendly...
 This edition of National Radio News
announces the FCC's approval of the first 15
FM broadcast licenses for stations spread across the country.
It is also the first issue following America's entrance into WWII and includes a
question from a Ham regarding whether simply listening to radio reports was allowed.
As you might know, the FCC prohibited amateur radio operators from transmitting
for any reason during both World War I and World War II. The reasons given
were clearing the airwaves to make monitoring easier, to prevent intentionally encoded
messages from being sent, and to keep homeland status information from being broadcast.
Homeland status could be ascertained by assimilating reports of who was being drafted
and entering service and...
 The
Stabistor, a specialized semiconductor device introduced in the 1960s, functions
as a voltage-dependent switch that remains an open circuit until its specific "break
over" voltage is reached, at which point it conducts current effectively. Popular
Electronics magazine highlighted its versatility, showcasing practical circuits
for sensitive meter overload protection, linear temperature-sensing bridges, signal
volume compressors, noise-squelching limiters, and voltage regulation. By utilizing
the forward conduction characteristics of silicon junctions, the Stabistor provided
a cost-effective alternative to more complex components of the era. Despite its
utility, the Stabistor is largely obsolete today...
 The effort to
block advertising on radio broadcasts has been going on for about
as long as advertising has been in use, as evidenced by this 1934 article in
Radio-Craft where a 'robot' advertising silencer' device is presented for removing
"superfluous advertising." Headlines from a few weeks ago announced Apple's program
for blocking ads that appear on websites, causing a big to-do about how all the
"free" content would be jeopardized since it is the advertisers who pay for the
music and other programming to be delivered to the user. Without the convenience
and economy of software to do the job in 1934, however, fairly complex discriminator
circuits were used to detect and mute the 'garrulous announcer or advertiser' between
regular programming. It's pretty funny to...
 "Direct-to-device (D2D) satellite services
were to the fore at Mobile World Congress 2026 in Barcelona. One of the main questions
that remain, however, is how well they will work indoors. Starlink talked about
their version 2 satellites at the show. Starlink and AST SpaceMobile must prove
whether satellite services can actually offer service indoors. The indoor question
Some industry analysts are still unconvinced by the possibility of indoor satellite
data and cell offerings..."
 TotalTemp Technologies maximizes our combined
40 years of experience in this highly specialized field to create new, alternative,
"Next Generation" temperature chambers and temperature testing equipment. In order
to best serve our customers, TotalTemp Tech publishes a technical Blog where our
designers post informative articles on the industry and our unique products. A new
blog post has been added titled "Space
Demand Rising: Powering up with Next-Gen TVAC Testing," wherein is discussed
the growing need for efficient, small-scale thermal vacuum (TVAC) testing equipment
as the U.S. space economy expands toward 2026. Key Takeaways Include: Market Drivers:
Increased activity from NASA, the Space Force, SpaceX, and global satellite initiatives...
 The advent of
metal-encapsulated vacuum tubes was supposed to be the death knell
for traditional glass tubes. This 1935 article from Radio-Craft spelled out the
many virtues of 'metal' tube and how in short order their superiority would obviate
the need - even desire - for "glass" tubes. I'll let you read the article for the
details, but want to make note of an evidently archaic term used that could potentially
be really popular in today's manufacturing world if duly resurrected - "quantiquality"
(aka "quanti-quality" or "quanti quality"). The connotation is a process of high
quantity in conjunction with high quality. The only references I could easily find
to quantiquality was from late-19th-century newspaper archives. If sometime within
the next few years you start seeing some...
 If you have been an RF Cafe website
visitor for a long time, you might recall back in 2010 when I posted How an Electrical
Engineer Spends "Vacation." It showcased the extensive electrical wiring I did on
my daughter's horse riding business. A few years ago, she and her husband, a major
in the USANG, moved to an old former diary farm property. The buildings are old
and dilapidated, but we are slowly patching and improving them. Earlier this month,
the new submersible pump we just installed late last summer stopped working. When
I measured the panel bus voltage, one leg read 120 V, and the other leg was
at about 70 V. Turns out the current that would normally be supplied by the
other 120 V leg was being supplied in series with the submersible pump motor.
This task was within my purview. Having performed many electric service heavy-ups..
 Battery technology experienced a major technology
evolution in the late 1950s similar to the one that took place in the late 1990s.
Prior to the 50s, most common portable batteries were of the carbon-zinc type and
were not rechargeable. Nickel cadmium (NiCad) cells existed, but were not in widespread
use largely because little was known about the chemistry and how it responded to
various charge and discharge cycles. Mercury, NiCad, nickel metal hydride (NiMH),
alkaline-manganese, began gaining popularity in applications requiring longer battery
life and more consistent discharge characteristics. In the 2000s, lithium polymer
(LiPo) and lithium ion (LiIon) underwent a similar evolution. Still, all the aforementioned
battery types are in use today...
 Since 2005, San Francisco Circuits has been
a trusted U.S. provider of advanced PCB manufacturing and assembly solutions for
R&D innovators, prime contractors, and integration experts.
Double-Sided Ball Grid Array (BGA) assembly allows designers to maximize component
density without increasing the board size. From smartphones and IoT devices to medical
and industrial electronics, this approach delivers higher pin counts in a smaller
footprint. BGA technology replaces traditional pins with solder balls under the
package, and placing BGAs on both sides of the PCB increases the usable area, letting
engineers create more compact and complex designs...
 This Radio Service Data Sheet covers the
Ford-Philco radio model FT9, 6-tube auto-radio receiver. A large
list is included at the bottom of the page of similar documents from vintage receiver
schematics, troubleshooting tips, and alignment procedures. They were originally
published in magazines like Radio-Craft, Radio and Television News,
Radio News, etc. I scan and post them for the benefit of hobbyists who
restore and service vintage electronics...
 Prior to atmospheric sounding rockets and
orbiting satellites, all information gained and theories developed on the nature
of Earth's upper atmosphere and its interaction with
electromagnetic waves were purely academic, not the result of
empirical data. That is not to say the theories were wrong (although some were),
just that they were incomplete. For that matter, even today there is still much
to be learned and, according to an excellent article in the October 2015 issue of
the ARRL's QST magazine titled "Five Myths of Propagation Dispelled," there is still a lot of
misinformation being believed and promulgated about shortwaves and how they travel
in the atmosphere. This work is a great testament to the level of expertise that
exists in the realm of Amateur Radio, and the...
|
 • FCC Requires
FRN Contact Information Change Within 10 Days
• India Targets
1B 5G Subscribers
by 2031
• 6G Coming - with
Connectivity & AI
• 5G
Americas Dissolves in 2026
• How
Hackers Break into Chip Fabs
• European
Digital Market Collision
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 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+ 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...
 According to this story in a 1945 issue of
Radio News magazine, Raytheon certainly had an ambitious plan with its
"Sky-top" network of microwave relay stations from border to border and coast
to coast. No orbiting satellites existed at the time, so purely terrestrial methods
were necessary. The basic idea was to build facilities at the peaks of the highest
mountains in the U.S. to enable high bandwidth, reliable, high quality broadcasting
of all known forms of services - television, facsimile, aircraft and nautical navigation,
telephone, emergency, et al. The funding and logistical investment would be enormous,
particularly with getting access roads, materials and electricity to all the remote
sites. Automation was to mitigate the difficulties involved in manning stations
fulltime, but there would be the need for periodic maintenance and repair. Plans
included tests for frequencies into K-band (26 GHz), which was really stretching
the limits of technology at a time when a few tens of MHz were challenging for most
applications...
 According to this 1972 article in Popular
Electronics, there were as many as 50,000 computers in the world at the time using
magnetic core memories. Among them was the Apollo Guidance Computer that was onboard
the Apollo 11 Lunar Module that Neil Armstrong used in July 1969 to land on the
moon*. Semiconductor memories were being manufactured in 1972, but believe it or not
they were not as fast as the magnetic core memories. Machinery was not available with
enough precision and repeatability to thread the read, write, sense, and inhibit wires...
 The following
technology-themed "Cryptoquip" appeared
in the Erie, PA, newspaper on December 26, 2019. It is from King Features Syndicate
and is likely covered by copyright. I attempted to find a webpage for it that I
can link to, but with no success. King Features Syndicate publishes a huge number
of my favorite comic strips. With a Cryptoquip, you try to decode a message by substituting
letters for the ones presented. It is usually pretty easy after you have done a
few. A clue is always provided for one letter. In this case it is F = P, so you
substitute the letter P everywhere you see the letter F. The message is usually
a form of pun (aka quip)...
 This custom
s-Parameters themed Crossword Puzzle for May 15th, 2022, is brought to you by
RF Cafe. Clues for words relevant to the theme are marked with asterisks (*).
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...
 Charts and nomographs are not nearly as
useful or necessary today for the design and troubleshooting of electronics due
to the ready availability of calculators in the form of computers, tablets, and
smartphones. Determining parallel and series resistance, capacitance, and inductance,
reactance, power dissipation, resonant frequency, voltage dividers, etc., can easily
be done with the push of a few buttons (or virtual touch-sensitive screen buttons).
Not only is it not necessary to know the equations behind the calculations, but
you don't even need the know how to enter mathematical operations into a calculator.
A lot of old-schoolers say the availability of newfangled electronic gizmos contributes
to the dumbing down of technicians and engineers. If you can't use a slide rule,
then you don't truly understand the science. I wonder if their attitudes were the
same when special-purpose cardboard slide calculators and even design charts like
this one and nomographs were published?
 Gimmick or brainstorm? I'd says the
Jerrold Magic Carpet Antenna is a little bit of both. Undeniably, it is a good
way to conceal a full-size antenna with the general characteristics of multi-element
broadband structure. The downside is that it is fixed in position and any directionality
will favor some stations while shunning others. Its installation inside removes
weather concerns - snow, ice, and wind - which is a major advantage. I have never
seen one, but the illustration seems to show that the antenna elements are integrated
into a fabric sheet (hence the "carpet" part of the name), so its geometry is fixed
and should be consistent as long as the installer takes care to not distort it.
On the other hand, based on my experience with television and FM radio antennas,
a bit of variation from the factory "textbook" shape often provides improved performance.
Ultimately, anything other than a high gain antenna mounted high off the ground,
and on a rotator will result...
 Space exploration and exploitation has always
advanced quickly. Sputnik and Explorer were launched in 1957 and 1958, respectively.
They were the world's first artificial satellites, and had only one-way communications
from onboard scientific payloads to earth stations which picked up the signals (many
amateur radio operators received the data as well). In a little over half a decade,
multiple two-way communications satellites were in orbit, and instrumented probes
had already reached the moon, Venus, and Mars. Results of the International Geophysical
Year (IGY) effort are rightfully credited with setting everything in motion. This
article from a 1965 issue of Popular Electronics magazine reports on the state of
the art in satellite technology. Not mentioned is the concurrent rapid advances
being made in rockets, tracking stations, and orbital and space navigation capabilities
which were an integral part of the program...
 In 1931, QST reader John H. Miller, Electrical
Engineer, of the Jewell Electrical Instrument Company, wrote to the editor regarding
the story "What Is This Thing Called Decibel?," by James L McLaughlin and James
J. Lamb, which appeared in the August issue of that year. Mr. Miller wished to inform
(or remind) readers that the
American Wire Gauge
system for assigning sizes to wire cross-section ratios closely follows a decibel
(i.e., logarithmic) relationship. Applying his information: A 28 AWG solid wire
has a cross-section of 160 circular mils, so at 3 sizes larger, 25 AWG should be
320 circular mils. In fact, it is 320 circular mils. A 12 AWG solid wire has a cross-section
of 5,630 circular mils, so at 3 sizes larger, 9 AWG should be 13,060 circular mils,
and it is 13,090 circular mils. That verifies the 3 dB per three differences
in gauge for two cases using small and large wire sizes. What about, say, 5 dB
for 5 wires sizes in difference? Using 28 AWG again as a reference, a 5 dB
increase in size for 28-5=23 AWG wire should be about...
 These "Radio
Term Illustrated" and "Technical Term Illustrated" electronics-themed comics
are amongst the best I can remember seeing. They appeared in two 1946 issues of
Radio-Craft magazine. For the uninitiated, WAVES is an acronym for Women Accepted
for Volunteer Emergency Service. They were a World War II phenomenon established
on July 30, 1942, half a year after the Pearl Harbor attack. Their Navy Reserve
status granted both commissioned officers and enlisted women official service duty
status for the duration of the war and entitled them to the privileges (and in some
case dangers) that came with it. As with women occupying manufacturing and even
airplane ferrying jobs previous dominated by men, WAVES freed up men to go fight
the war. The artist, Frank Beaven (FB), solicited suggestions from readers and then
turned them into a sort of double entendre form of comics...
 National defense needs have pushed back
the frontiers of science and technology since time immemorial. Mechanics, chemistry,
medicine, mathematics, psychology, astronomy, electricity, and as of the late nineteenth
century, electronics. Astronomy was useful as a navigational tool and required a
very sophisticated knowledge of geometry and algebra to make it accessible to seafaring
men, cartographers, and land surveyors. Since the early 1900s,
radio astronomy has played a huge role in the advancement of super-sensitive
receiver designs. Most people think of information arriving to them in two or maybe
three forms: sound, visible light, and some (but not many)
even consider radio waves. As over-the-air AM and FM radio broadcasts die out, even
fewer people are aware of radio waves; they certainly don't think of their WiFi
or cellphone signals...
 Do you detect any (probably unintended)
irony in the page 76 comic from a 1947 issue of Radio-Craft magazine? It
shows a husband and wife shopping for a new radio and has the husband telling the
salesman, "I don't care if it is FM - I want one that plays in the P.M.!" I'll let
you think on it for a moment. As with many of the comics that appeared in the magazine,
the scenarios were suggested by readers. The other comic played on the common music
programming schedule that included times of "dinner music," "evening music," etc.
If you like these comics, then you'll appreciate the huge list at the bottom of
the page of others with tech themes.
 Radio Corporation of America (RCA) was not
the inventor of the telegram, but it did decide that the status quo transmitting
and delivery services available like the Marconigram were in need of improvement.
Accordingly, in 1929 the company initiated its
RCA Radiogram, as promoted in this 1947 issue of Radio-Craft magazine. A promotional
brochure printed by RCA in 1950 entitled, "What it is - What it does," contrails
a lot of detail about the radiogram, including many photos of the operational offices.
RCA Radiograms initially could be sent from ship to shore, shore to shore, ship
to ship, or shore to ship. No mention was made of being able to send them to/from
aircraft. At the time, the cost was 21¢ per word. As with most things, authentic
RCA Radiograms...
 This custom RF Cafe
electronics-themed crossword puzzle for May 21st contains words and clues which
pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. Being that "T" is the 21st letter of the alphabet, it is used as the first
and/or last letter of many words in today's crossword puzzle. As always, you will
find no references to numbnut movie stars or fashion designers. Need more crossword
RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating
back to the year 2000. Enjoy.
 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, and
more. Page templates are provided with a preset scale (changeable) for a good presentation
that can incorporate all provided symbols...
 In a Scientific American article
titled "Elemental
Urgency," Jennifer Hackett reported on a paper published in 2013 by Yale University's
Thomas Graedel et al regarding the availability (or unavailability) of the raw elements
- and suitable substitutes - used extensively in modern manufacturing. Unlike half
a century ago when most products were made from relatively common and easily obtainable
elements like lead, iron, tin, nickel, aluminum, carbon, zinc, silicon, and even
silver and gold, many more elements are now regularly included in mass manufacturing
processes. Rhenium (Re), used in high strength, temperature alloys to applications
like jet engine turbine blades and as a catalyst in chemical processes, is one of
the most critically rated elements for uniqueness. Ditto for titanium. Yttrium (Y),
used in the familiar YIG oscillator and YAG laser, is another critical element.
Keep in mind that this chart rates elements not solely according to scarcity, but
how critical they are in processes where no other element can be substituted in
the event of a shortage. Lead (Pb) is a clear example of an element that is abundantly
available, but the materials in which it is used cannot be easily replaced with
another element...
 This is the electronics market prediction
for
Belgium, the land of Hercule Poirot, circa 1966. It was part of
a comprehensive assessment by the editors of Electronics magazine of the
state of commercial, military, and consumer electronics at the end of 1965. Military
systems for NATO and television sets were a big part of the picture. Unless you
can find a news story on the state of the industry, detailed reports must be purchased
from research companies. Their website has a lot of charts on Belgium's current
electronics market showing revenue in the consumer electronics segment amounts
of US$2.56B in 2025. The $346.4M reported in 1965 is the equivalent of $3.50B in
2025, representing a drop of nearly 27%...
 Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your Banner Ads are displayed on average 225,000 times per year! 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. If you need your company
news to be seen, RF Cafe is the place to be... |
