|
 In 1936, a high school graduate could expect
to earn about $15 per week, or about 38¢ per hour (40-hour week), in the
nascent radio business. According to the U.S. Bureau of Labor Statistics' Inflation
Calculator, that is the equivalent of around $348 per week in 2026, which is not
much to live on these days. Today, many McDonalds burger flippers are being paid
$15 per hour ($600/40-hour week). That equates to a little over $26 per week in
1936 - nearly twice as much as an electronics technician who likely had military
and/or technical school training. This 1936 Radio-Craft magazine article discusses
the benefits of formal education in regard to potential earnings...
 "NTT DOCOMO, a Japan-based mobile network
operator providing telecommunications services including mobile voice, data, 5G,
and digital solutions for consumers and enterprises and Keio University Haptics
Research Center have conducted a demonstration of high-precision
remote robot operation over commercial 5G. By combining Configured Grant, a
low-latency network slicing technology, with Keio's Real Haptics® technology, force
feedback and tactile sensations were transmitted stably. The demonstration marks
the first instance of Configured Grant being used to enable practical robot teleoperation
over commercial 5G..."
 Radio-Craft magazine ran a series
of feature articles on "Men Who Made Radio." The January 1930 edition honored Canadian
engineer
Reginald A. Fessenden, who is credited for making the first
wireless voice transmission. Mr. Fessended worked with both Thomas Edison and
George Westinghouse, eventually inventing the rectifying electrolytic detector,
which was the successor of the coherer and the precursor of the crystal and the
tube detectors. His interest in communications extended beyond radio to include
sonic devices like sonar, a field in which he also gained significant renown...
 What was considered in 1937 to be a breakthrough
feat for a full-size airplane is today accomplished regularly in model airplanes.
What took hundreds of pounds of generators, radio gear, sensors, and actuators to
perform the first-ever
fully automatic landing is now done with a few ounces of microminiaturized
GPS receiver, processor, MEMS sensors, servos, and a LiPo battery. The HobbyZone
Sportsman S+RTF (see video at bottom) is an example. Most modern commercial aircraft
are capable of landing themselves in an emergency situation. Just today there was
a news report of an American Airlines pilot that died in flight and the copilot
took over to land the airplane...
 Conceptual dilemmas in electronics (and
other fields) often arise from foundational misunderstandings that can be resolved
through rigorous analysis. This Popular Electronics magazine article addresses
three primary paradoxes that frequently confuse beginners. First, the "plus-and-minus"
debate regarding current direction is clarified as a semantic convention: while
electrons physically flow from negative to positive, the historical definition of
current often assumes the opposite direction, provided one remains consistent. Second,
the capacitor-charging paradox, which seems to contradict the near-light-speed transmission...
 Here are the schematics, chassis layout,
and service info for the
Howard Explorer Model W Deluxe 19 Tube All-Wave Superheterodyne
radio. The Radio Service Data Sheets that were published in Radio-Craft
magazine usually seem to have more information included than those published in
other magazines, at least in the same era (1940-ish). It might have to do with how
much material is provided by the manufacturer rather than a decision by the magazine
editors. Believe it or not, there are still people searching for such data...
 "SpaceX satellite policy lead Udrivolf Pica
told participants in the International Telecommunication Union Space Connect webcast
about the next-generation Starlink direct-to-device (D2D) cellular service for smartphones.
The revelation of the new service follows SpaceX's October 2025 U.S. trademark filing
for "STARLINK MOBILE" and comes as Elon Musk has recently hinted at Starlink mobile
ambitions. 'We are aiming at peak speeds of
150 Mbps per user,' Pica said, adding, 'So something incredible if you think
about the link budgets from space to the mobile phone..."
 On a fairly regular occasion someone will
write to one of the QST magazine columnists or post on a forum asking about information
on a particular antenna configuration he recalled seeing printed many moons ago,
but can no longer find anything on it. Fortunately, the columnists are guys who
have been in the Ham game for a many decades and not only remember what the writer
references, but knows where to dig out the original info. Even with the plethora
of resources available on the Web, some things still cannot be found because nobody
yet has posted it. That is one of my prime...
 Hiram Percy Maxim is well-known by amateur
radio operators as the founder of the American Radio Relay League (ARRL). He died
in 1936 and was buried at Rose Hill Cemetery in Hagerstown, Maryland. A few years
ago while visiting relatives in Hagerstown, I went to the cemetery, took some photos,
got the exact GPS coordinates, and posted a short article on it (see
Hiram Percy Maxim's Gravesite in Hagerstown, Maryland). If
not for my documentation, there would be no way to know that the large grave marker
shown in this 1940 QST magazine article does not belong to the esteemed
Mr. Maxim, but to the matron of his wife's family...
 Here are a couple
high tech comics for your enjoyment from the pages of the July
1961 edition of Electronics World magazine. I'm guessing the joke in the
page 72 comic is that unknown parts were/are generically referred to as "Brand
X," so hopefully that would bring in customers who couldn't identify components
(which the repairman probably could). It could also be an unintended warning that
if "Brand X" (knockoff part) is sold there, then there is a good chance inferior
parts will be used in the repair. The page 94 comic is yet another play
on the huge popularity of home hi-fidelity (hi-fi) sound systems of the day. Amplifiers
still used vacuum tubes so building speaker driver circuits that could handle hundreds
of watts was easy to do...
 Fifth in the "Men Who Have Made Radio" series,
Heinrich Hertz is honored here for giving mankind what author Hugo Gernsback appropriately
termed "a sixth sense." Having earned his doctorate with a thesis on "the distribution
of electricity over the surface of moving conductors," Hertz proved through his
experiments the existence of electromagnetic waves - the aforementioned sixth sense.
During his short 37 years on Earth,
Heinrich Hertz accomplished an impressive amount of fundamental
research and discovery. He was remembered fondly as a kind man who placed advancing
the frontiers of science ahead of fighting for credit...
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes. The
WMRD09-7.2-S is a 9-way resistive splitter that covers from DC to 7.2 GHz
with ultra-wide bandwidth. This unique design accomplishes extremely flat frequency
response in a small radial package. Our unique design approach provides higher than
expected isolation between outputs at far ports than would be achieved in a typical
star topology. It has applications in markets such as CATV, T&M, and military
radio...
 While watching the Avengers: Age of
Ultron movie, at some point when one of the computer voices was speaking, a
memory of the "This
Is DigiTalker" voice suddenly came to mind. Back in the mid-1980s while working
at Westinghouse in Annapolis, Maryland, a couple of the engineers brought a DigiTalker
prototype experimentation board into the super-classified area where I worked. According
to National Semiconductor's datasheet, it was introduced sometime around 1980. The
programmable digital voice IC was a big deal in that unlike other devices that had
a fixed set of...
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
 Some things never change - at least at the
fundamentals level.
Electric circuits is one of those things. I don't remember when I first became
interested in electrical apperati, but it must have been due to a natural affinity
to the science because nobody in my family or my circle of friends expressed any
interest. I was the odd man (or boy) out on my street, because while all the other
kids were playing baseball, basketball, and football, I was sticking forks in electric
sockets and disassembling flashlights, battery-powered toys, and building Erector
Set contraptions using the included electric motor. That's not to say I ever got
really good at it, but significantly better than I ever got at playing sports...
 You would be forgiven in this era of ubiquitous
cellphone usage for thinking maybe
Citizen Band (CB) radios are only used these days by techno-throwbacks
like myself, but the fact is many truckers still use them for convenience as well
as to avoid having all their communications intercepted, monitored, and recorded
by government agencies. It can be a deceiving sense of privacy though, because police
officers often monitor CB radio transmissions while in patrol cars, and even solicit
the assistance of other CBers in identifying and apprehending suspected transgressors
- an advantage of public, unencrypted conversation afforded law enforcement which
is not available with cellphones. Also, CB transmission, even though usually regarded
as "hearsay" in legal venues, has many times been admitted as evidence in cases
where "present sense impression," "excited utterance," or some other special...
 I have experienced the problem with low
precision AI calculations; however, it will use high precision if specifically instructed
to do so. "AI has driven an explosion of
new number
formats - the ways in which numbers are represented digitally. Engineers are
looking at every possible way to save computation time and energy, including shortening
the number of bits used to represent data. But what works for AI doesn't necessarily
work for scientific computing, be it for computational physics, biology, fluid dynamics,
or engineering simulations. IEEE Spectrum spoke with Laslo Hunhold..."
 This week's
Science & Engineering Crossword Puzzle, as is the case with all RF Cafe
crossword puzzles, has only words and clues related to science and engineering.
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.
 "And there is nothing new under the sun."
- Ecclesiastes 1:9, NKJV (did you know that is the origin
of the saying?). This 1930 editorial by Radio-Craft editor Hugo
Gernsback describes a coordinated scam perpetrated by
radio manufacturers to compel consumers to buy new sets rather
than have their existing sets repaired. In short, retail prices were inflated to
accommodate a built-in 'trade-in' allowance that far exceeded the repair cost or
used radio cost. Radio service shops were getting the short shrift because many
people who might have otherwise elected to have repairs made would instead trade
in the old set for a new one...
 It really wasn't all that long ago when
most people worked on computers with Color Graphics Adapter (CGA) that had just
16 colors (4-bit pixels). In the late 1980s (wow, maybe it really was a long time
ago), the luxury of a 256-color (8-bit pixels) Video Graphics Adapter (VGA) monitor
and video card would cost you around $300 each. I recall seeing ads for "16 million
color" displays by ViewSonic that ran north of a kilobuck. My first "real" monitor
was bought in 1987 and was 4-bit monochrome.
Televisions, as you know, began as black and white (actually a
infinite number of gray levels between black and white). When TVs first arrived
in people's homes, they were glad for any kind of display, but it wasn't long before
marketing gurus convinced the masses that...
![To Be, Or Not to Be [a Metal] - Do Astrophysicists Know the Difference?: Kirt's Cogitations™ #374 - RF Cafe](miscellany/homepage-archive/2026/images/big-bang-universe-creation-kirt-blattenberger-hp.gif) As a multi-decade-long amateur astronomer,
I have read countless articles written by
astronomers who refer to all elements heavier than helium (#2 on the periodic
table of the elements) as "metals." Ostensibly, the origin stems from early detection
of heavy elements in stars, based on heliographic spectrum investigations, where
iron - being the most abundant stable byproduct of supernova explosions - was most
readily observed. I wondered if the "metals" nomenclature came from the next heaviest
element, lithium (#3 in the periodic table), being a metal, thereby laying the foundation.
Not so, claims AI, since lithium is very rare overall in the universe, and not readily
observed. For clarity, I also procured the scientific distinction...
 I usually learn something new with each
episode of Mac's Radio Service Shop, but not necessarily related to electronics.
Such is the case this time where after Mac gives Barney a quick lesson in how to
determine a transformer's winding turns ratio when needing to create an impedance
match circuit. He then, while discussing whether "free" repair estimates are truly
free or of any real value at all, he uses the phrase "a horse on you." Maybe it is because I don't frequent bars that
I had never heard that, but after a little research I now know it refers to a bar
dice game called "'Horse." "A horse on you" is when you lose the final round of
a 2-out-of-3 challenge. "A horse apiece" is when you and your opponent each win
one round in a 2-out-of-3...
 "Data centers for AI are turning the world
of power generation on its head. There isn't enough power capacity on the grid to
even come close to how much energy is needed for the number being built. And traditional
transmission and distribution networks aren't efficient enough to take full advantage
of all the power available. According to the U.S. Energy Information Administration,
annual transmission and distribution losses average about 5%. The rate is much higher
in some other parts of the world. Hence, hyperscalers such as Amazon Web Services,
Google Cloud and Microsoft Azure are investigating every avenue to gain more power
and raise efficiency. The potential virtues of
high-temperature
superconductors..."
 Consumer grade
thermoelectric coolers have been around for so long now that most
people probably assume there is nothing wondrous about the discovery that makes
them possible. I still marvel at the process that allows the application of a current
through physical junction of two dissimilar metals (certain
types) to produce a cooling effect rather than the I2R heating normally associated
with conductors. This article from a scientist at Westinghouse Electric's research
laboratories provides a nice introduction to the subject of thermoelectricity from
both electric current generation based on the application of heat to a dissimilar
metals junction, and the aforementioned cooling effect possible from passing a current...
|
 • 6G
Spectrum Sharing Shows Promise
• FCC Expands
Unlicensed Use of 6 GHz Band
• Active
Smartphone Installed Base up 2% in 2025
• FDA Clarifies
Wearable Device Rules
• Revisiting the
1996 Telecommunications Act
• China's
BeiDou Satellite (their GPS) Does Emergency Messaging
 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.
 One of the best ways to learn about how something
work is to build and operate it yourself. This article from a 1974 issue of Popular
Electronics magazine presents a
voice scrambler that exploits a simple spectral inversion technique to create
a mirror image of the original voice spectrum. Spectral inversion occurs whenever
the difference frequency is taken during a mixing process, so that low frequencies
are translated to the high end of the band and high frequencies are translated to
the lower end of the band. The result in the case of audio (voice) is garbled sounding
speech. It is probably the simplest form of scrambling that is easily unscrambled,
but it serves as a good learning tool...
 "Eventually," Dr. Herwald said, "we believe it
will even be possible to automatically and continuously produce actual electronic equipment,
such as radio receivers and amplifiers, starting from a pool of molten semiconductor
materials." That was in early 1960 in an Electronics World article titled, "Molecular
Electronics." The term "molecular" references what eventually became integrated circuits
(IC), the first of which was realized in 1958 by Texas Instruments engineer Jack Kilby.
Kilby's IC incorporated one transistor, one capacitor, and three resistors on a germanium
substrate. Building on that success, researchers envisioned single-chip semiconductors
which contained hundreds, thousands, and even millions of transistors, diodes...
 In this episode of John T. Frye's "Carl &
Jerry" series, the intrepid pair of teenage electronics hobbyists and Ham radio
operators are experimenting with an audio amplifier rig that uses a parabolic dish
for concentrating sound waves at a focal point where they have a microphone mounted.
Aside from picking up bird noises and a neighbor lady scolding her husband for not
properly washing the windows during a round of Spring cleaning, Carl imposes upon
Jerry for a lesson in
feedback techniques - both positive and negative - and the reasons one is preferred
over the other. The story winds up with a clever double entendre comment referring
to osculation...'
 If you think paying $80-$100 per night for
a relatively low end chain hotel/motel is outrageous, then this advertisement in
a 1930 issue of Radio-Craft magazine will help justify your indignation.
While in California for the
IMS 2016 show, a convention-goer likely paid $200 or more per night for a room
within walking distance of the Moscone Center in downtown San Francisco. Compare
that rate to, say, the Eastgate Hotel or St. Clair Hotel in Chicago in 1930. Room
prices started at $2.50 - including free garage parking. The Madison Hotel in Atlantic
City had rooms starting at $4 per night that even included "Showers and Baths Throughout."
According to the CPI Inflation Calculator published by the U.S. Bureau of Labor
Statistics, $2.50 in 1930 is the equivalent of $45.58 in 2023 currency, and $4.00
equals $72.93. Those were prices for downtown medium grade hotels in downtown areas
of major cities. Yeah, you're being shaken down, alright...
 In case such things interest you, this first-person
story of a
ship's wireless operator, or "op," - the guy who manned the radio room - provides
a little entertainment and insight into transoceanic travel in the 1930s. Per this
1932 Radio News magazine article, the author's trip was made less than
two decades after the demise of the "unsinkable" RMS Titanic, where surviving passengers
and crewmen were saved partially due to the heroics of the telegraph operators.
Having never traveled on the water beyond the Chesapeake Bay, I wouldn't know how
to compare today's voyage with those of yesteryear. Do passenger ships nowadays
sometimes idle for three weeks in Central American waters while waiting for passage
through the Panama Canal? Can anyone identify the story's ship shown in the photo?
Evidently Griffin was not permitted to name it because of the less than totally
complimentary...
 Each edition of Radio-Electronics
magazine featured a couple pages of industry news entitled "The Radio Month." This
August 1949 issue started out with a rather tragic items reporting on the death
of Philco chairman John Ballantyne evidently while making a speech at his 13-year-old
son's school commencement ceremony. It's hard to imagine the scenario. Also included
was news of one of the first attempts in the country to impose training and licensing
mandates on electronics repairmen. Illinois and New York led the effort. Fortunately,
the attempted legislation did not succeed. The
Federal Communications Commission (FCC) marked it 15th year of existence as
a federal bureaucracy after it replaced the former Federal Radio Commission (FRC)
in 1934...
 A few years back, I bought the issues of
The Saturday Evening Post which contained the very first published comics from Peanuts
creator Charles Schulz. As with just about everything else, they were available
on eBay for a few bucks apiece (although prices have really gone up since the beginning
of the year). Most of the issues also had articles and advertisements - and even
comics - that make appropriate fodder for both RF Cafe and my hobby website,
Airplanes and Rockets. Here are a few of the tech-related comics I found. The first
one might seem to be a bit distasteful to the survivors of the RMS Titanic
disaster and/or their relatives, given that only 36 years had passed. The next one
is about architectural engineer - ahem, and the Hazel comic applies for obvious
reasons...
 An update has been provided by Michael M.
with more information about the Earth-Space propagation calculation DLL provided
free of charge by the French organization Centre National d'Études Spatiales (CNES,
National Centre for Space Studies). The
PROPAGATION dynamic
link library (DLL) contains functions to compute propagation losses according
to ITU-R P.† recommendations. Versions are available for both 32- and 64-bit
Windows and Linux operating systems, as well as for the C and Visual Basic programming
languages. Very conveniently, the DLL functions can be referenced from within an
Excel spreadsheet as well. A full list of the functions is given below, including
ones for gaseous, cloud and rain attenuation that factors in temperature, precipitation
intensity, and atmospheric noise, as well as for inputting geographic location...
 You've heard of
"Litz" wire, right? It's the twisted bundle of multiple enamel
or otherwise coated wire used for making couplers, antennas, and at frequencies
up to about a couple MHz. Congratulations, but did you know the full name for it
is "Litzendraht?" Neither did I until after reading this article. Litzendraht does
not derive from the surname of a fellow named Otto or Wolfgang Litzendraht, but
is the German word meaning "braided wire" or "woven wire." Litzen by itself means
braided or stranded. So, technically if you call it Litzendraht wire, you are being
redundant since it is the same as saying woven wire wire. That might save you some
embarrassment one day if you happen to be working around a German techie. Litzendraht
is used in order to exploit the skin effect at high frequencies where the majority
of the current is conducted on the wire's surface. Using multiple insulated wires
enables greater current carrying capability...
 A nice article by Donald Lancaster appeared
in an issue of Radio-Electronics magazine that introduces and puts into
layman's terms the relatively new (at the time) world of
digital logic circuits. Rapidly falling prices and equally
rapidly rising performance fuelled the craze. By 1969, most of the barriers
preventing former never-tubers from adopting the fledgling semiconductor
paradigm and there was by then a new generation of electronics hobbyists,
technicians, and engineers who had "grown up" on transistors and integrated
circuits. I like the author's analogies for AND gates and OR gates that involve
the familiar objects that include a garden hose with the house tap and nozzle,
and the kitchen sink faucet with the hot and cold handles. It's interesting how
often water, a substance generally to be avoided around electricity...
 Wayyyy.... back in 1992, RF Design
magazine (Gray Breed was editor at the time) ran a
software
contest. Those were the days when most engineers and hobbyists wrote software
in either Basic or Fortran. I happened to use Turbo Pascal, by Borland. At the time,
I was working as an RF engineer for Comsat, in Germantown, Maryland. Having done
a lot of frequency conversion designs in my previous work at General Electric, and
even more there at Comsat, I had already written a crude program to calculate mixer
spurious products, so this challenge gave me the excuse I needed to refine the user
interface and add some creature comfort features like loadable mixer spur files
and detection of spectral inversion if present. Although I did not win the grand
prize, I did win the runner-up prize. The prizes included having the following article
published in the November 1992 edition of the magazine, a couple experimenter kits
of surface mount inductors and resistors, a T-shirt, and a couple other items. Of
course, the greatest prize as far was I was concerned was having an article published
in a major magazine...
 "Are
we killing the broadcasting goose, layer of many golden eggs?" Dr. Lee de Forest
asked in his inaugural address, upon his election to the presidency of the Institute
of Radio Engineers. So went the opening editorial in a 1930 edition of Radio
News magazine. It was directed at the question of whether excessive, "gratuitous"
advertising was going to be so offensive to listeners that they would turn off the
set and go back to their former silent worlds. Remember that many, if not most,
households, and certainly not automobiles, even had radios at the time. Building
an audience was essential to nurturing the new phenomenon of radio, and to saturate
the listeners with commercials would surely doom the medium. Dr. de Forest would
be truly depressed if he could see the commercial broadcast landscape today with
it consisting of 15-20% advertising content and much of the rest filled with political...
 Here from a 1965 issue of Electronics
World magazine is a really nice write-up on
electrical noise, both how it originates and how it affects receiver systems.
Although vacuum tubes were still the predominant active amplification components
in 1965 (the date of this article), semiconductors were already solidly ensconced
in the signal detector role. I have to confess to learning a new term that I probably
should be familiar with: Equivalent-Noise-Sideband-Input, or ENSI. It appears also
in Reference Data for Engineers: Radio, Electronics, Computer, and Communications.
Interestingly, this is the first time in a long time I have seen noise referred
to as "grass;" the drawings make it clear why the moniker was created. We were taught
to use "grass" in USAF radar tech school and used it in common parlance...
 This
Microwave Engineering Crossword Puzzle for April 11th has many 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!
 This Radio Service Data Sheet for the
General Electric Model HJ-1205 floor console model vacuum tube radio came from
the June 1940 edition of Radio-Craft magazine, published by Hugo Gernsback.
Console type floor model radios had plenty of space for large speakers, more effective
built-in antennas (usually mounted around the perimeter of the back of the cabinet),
and more convenient tuning and sound adjustment controls. The HJ-1205 featured "feathertouch"
pushbuttons. Some of the early pushbutton tuning mechanisms took a pretty heavy
finger to manipulate. I post these for the sake of hobbyists and historians searching
for information on vintage electronics. If you happen to own one of these radios,
whether in its restored or unrestored condition, please send me a photo and I will
be glad to post it here with attribution to you...
 Although the article's title specifies "electronic
hobbyist," the advice applies equally well to students and professional technicians and
engineers. A few of the
tools are no longer available from the original manufacturers, but modern
equivalents - often of better design and quality - are available. If you are
nostalgic for the originals, though, you can always look for them on eBay;
there's not much you cannot find there if you wait long enough. To show how much
times have changed, get a load of (pun intended) that pistol-shaped soldering
gun. Can you imagine the mayhem that would ensue if it showed up in a high
school electronics lab today? For that matter, is a classic Weller soldering gun
allowed? Can you even say "soldering gun?"...
 The
thyratron is not necessarily a familiar type of vacuum tube to most RF and microwave
electronics practitioners unless they happen to be involved in radar, imaging (x-ray),
particle accelerators, etc.† It is basically a high speed, high current switch used
in pulse forming networks for firing magnetrons (via a high-voltage transformer).
Both the S-band airport surveillance radar and the X-band precision approach radar
I worked on in the USAF employed thyratrons. The X-band radar had been modified
by the time I came on the scene to use a solid state thyratron (one of the earliest
adaptations), but the S-band radar still used its original vacuum tube thyratron.
While I don't recall for certain, I believe the thyratron in the thumbnail image
is the one it used. The accompanying ruler...
 You always need to pay careful attention
to "breakthrough" type articles when they appear in April issues, since many magazines
have a tradition of burying an "April Fools' Day" item without notice. This April
1932 issue of QST magazine seems to be legitimate. The term "lycopodium
pattern" aroused my suspicion, but it turns out to refer to a pattern of vibration
that resembles the needle orientation of certain pines and cedars. As radio frequencies
continued to increase during the early years of "wireless" development, the use
of quartz crystals as a stable reference source ran into a physical limitation because
as crystal slices reached a certain thinness, overtone and subharmonics appeared
that caused problems in circuits. A new mineral called tourmaline saved the day.
With an elasticity much greater than quartz, tourmaline is able to vibrate at higher
fundamental frequencies for a given thickness... |
