|
 Carl and Jerry stories are usually a good
mixture of teenage curiosity, adventure, and electronics technology, but this "Out
of the Depths" episode is a bit too far-fetched. The first ninety percent of
this 1957 Popular Electronics magazine tale fulfills expectations, with
the boys applying their shared interest in technology while attempting to learn
and apply the technique of luring elusive fish from their safe dwelling places and
onto the ends of their hooks. A car battery, DC-to-AC inverter, tape recorder, and
high-gain microphone are the basis for the scheme. Things were going well, and I
expected the normal hard-fought victory with big, fat bass in their creels - and
then something only slightly more believable than finding a crashed alien spaceship...
 RCA, the
Radio Corporation of America was not merely a manufacturer of
radio, television, and phonograph equipment for home entertainment. The company
also made vacuum tubes for all sots of electronic equipment, and produced a weekly
radio broadcast called "Magic Key" on the NBC Blue Network. Sticking to their communications
roots, RCA today markets televisions, microwave ovens, Android-based tablet computers,
DVD / Blu Ray drives, telephones, 2-way radios, radios, clocks, antennas, and many
other devices - with no tubes in sight, not even in their TV displays...
 "Scientists at the University of New Hampshire
are using artificial intelligence to dramatically speed up the search for
new magnetic materials. Their approach has produced a searchable database containing
67,573 magnetic materials, including 25 previously unknown compounds that retain
their magnetism at high temperatures, a key requirement for many real-world applications.
'By accelerating the discovery of sustainable magnetic materials, we can reduce
dependence on rare earth elements, lower the cost of electric vehicles and renewable
energy systems, and strengthen the U.S. manufacturing base,' said Suman Itani, lead
author of the study..."
 Breaking News!
Espresso
Engineering Workbook™ v3.2.2026 has just been released. This makes the 49th
worksheet added. It calculates magnitude, phase, and group delay for Butterworth
and Chebyshev lowpass, highpass, bandpass, and bandstop filters. Outside of the
kilobuck simulators, finding a calculator for phase and group delay is extremely
difficult - believe me, I've searched extensively for years. Espresso Engineering
Workbook™ can be downloaded free of charge. All you need is Excel™ v2007 or newer.
It is provided compliments of my advertisers. Contact me if you would like your
company added to the next release.
 Disneyland opened its gates in Anaheim,
California on July 17, 1955. It was billed as the most high-tech theme park in the
world, with a "wow" factor on par with the World's Fair extravaganzas. One of its
much-ballyhooed features was the "realistic" jungle safari tour with life-like animal
automatons and authentic 3-D jungle sounds. This article, published less than a
year after opening day, highlights some of the equipment and methods used by artists
and engineers to achieve the effects...
 Established in 1990,
dB Control supplies mission-critical,
often sole-source, products worldwide to military organizations, as well as to major
defense contractors and commercial manufacturers. dB Control designs and manufactures
high-power TWT amplifiers, microwave power modules, transmitters, high- and low-voltage
power supplies, and modulators for radar, ECM, and data link applications. Modularity
enables rapid configuration of custom products for a variety of platforms, including
ground-based and high-altitude military manned and unmanned aircraft...
 You will love the irony at the end of this
Carl Kohler technodrama. It appeared in the June 1957 issue of Popular Electronics
magazine. I'm not going to spoil it by even hinting at the conclusion - only that
the story follows the familiar path of the dauntless husband-electronic-hobbyist
taking off on another of his somewhat hair-brained ideas, while "friend-wife" looks
on. Her self-restraint is tested, as usual - although she jabs with some uncharacteristically
harsh zingers this time. Have you noticed how men are expected to be self-deprecating
in situations in order to create humor? The technology here was considered bleed-edge
back in the day. BTW, I fed the husband's humor bait to AI and it came up with some
pretty good responses - like what had been expected by him. AI came up with
a long name for FUNIAC (clearly a play on names like UNIVAC and ENIAC)...
 "The Whistler
and His Dog" is one of those tunes that you have probably heard dozens of times
but never knew the title of it (video at bottom of page).
It is mentioned in this installment of "Mac's Radio Service Shop" from a 1948 edition
of Radio & Television News magazine. Barney is said to have been whistling
it while replacing an output transformer on a receiver-recorder... a wire recorder
at that. The "20 Questions" theme is from the game where the player attempts to
guess the answer by asking a series of questions that narrows the possible results
until only the correct one is left - aka deductive reasoning. BTW, I'll bet "The Syncopated Clock" is another tune you've
heard many times but didn't know the title of it...
 Have you noticed how many wooden utility
poles are
bending under the load of communications cable weight they were never designed
to withstand? Some are ridiculously burdened - and it is not "engineered deflection"
for line tension changes. Power companies want to charge the communications companies
for pole and/or cross bar replacement and/or upgrading, but the FCC just ruled that
pole owners cannot charge the full cost of replacement. That financial deficit,
of course, gets passed on to electric power customers. You wonder why your monthly
bill has skyrocketed in the last few years? That is part of it - along with
us peoples subsidizing wind and solar generation, and paying for free Internet and
cellphones to half the population (including Illlegals). Do you fell violated? I
do.
 Radio-Craft magazine solicited inputs
from its readers for a series of "Radio
WittiQuiz" questions and answers related to radio and electronic, with a stipulation
being that there had to be some aspect of humor included. That meant that some of
the multiple choice answer options needed to be inane. For most of the questions,
the process of elimination is pretty easy, but a couple could cause some head scratching
- especially if you are not really sure of the answer. This group starts at number
28, so obviously preceding issues had questions 1 through 27. At some point I will
probably acquire them and post other Radio WittiQuizzes...
 Having never been a sports aficionado, I
have not spent much money or time at baseball, football, or soccer fields, hockey
rinks, bowling alleys, curling sheets, or basketball courts. When an air show comes
to town, however, I'm there. I'll stand in line for 45 minutes to tour the inside
of a DC-3, B-25, B-17, PBY-5, or just about anything that will admit me. What is
particularly enjoyable is inspecting the radio equipment racks and bays. The sight
and smell (I consider it an aroma) of the old UHF
and VHF sets, recording equipment, power supplies, generators, synchros, and the
associated wiring and connectors is something I never tire of experiencing. I always
imagine the men who operated and maintained everything doing their assigned duties
to keep those wonderful machines flying...
 The
Chronistor, which appeared in a 1958 issue of Popular Electronics magazine,
was a compact elapsed time indicator in the form of a common glass fuse. Powered
by electroplating, it requires roughly 1 mA of DC current to migrate metal
ions from anode to cathode via an electrolyte, resulting in visible cathode deposition
along a glass-printed hour scale. Standard options included 500, 1000, or 2500-hour
ranges, with specials (like a 1-year, 8760-hour version) from Bergen Laboratories.
The article outlines a basic series circuit for AC line operation, comprising a
half-wave rectifier, pilot lamp, and limiting resistor for the Chronostat...
 If
you have kids, you'll probably appreciate these two
comics that appeared in the May 1956 issue of Young Men • Hobbies • Aviation
• Careers magazine. Young Men was a fairly short-lived publication,
having existed for only a couple years around the 1956 timeframe. It was not affiliated
with the Academy of Model Aeronautics (AMA), which had its own series of magazines.
Howard McEntee, famed radio control pioneer, was on the staff, and Albert L.
Lewis was editor. Unlike the other aviation magazines of the day, Young Men covered
a broad range of activities and hobbies including model boating and cars, electronics,
chemistry, physics, school, amateur magic tricks, shooting, and more.
 "Google's parent Alphabet has reached a
definitive agreement to
acquire renewable energy developer Intersect Power for $4.75B, a transaction
that signals a structural transformation in how Silicon Valley intends to power
the AI era. By owning a power utility, Google can secure energy for its data centers
directly. This acquisition marks a departure from the industry's decade-long standard
of signing Power Purchase Agreements, where companies contract for energy from third-party
developers. Instead, Google is taking ownership of a 3.6-GW pipeline of late-stage
solar and wind projects, along with 3.1 GWh of battery storage..."
 Well... it was 50 years ago referenced to
the year this story was published in 1937. That makes it 138 years ago referenced
to 2025. The story's point is that half a century had passed already since the confirmation
of existence of electromagnetic waves as proposed by James Clerk Maxwell.
Heinrich Hertz's "Funken-Induktor" (spark inductor) and his "Knochenhauershen
Scheiben" (Karl-Wilhelm Knochenhauer's disk-type capacitors) were key to his ability
to generate, transmit, and receive EM energy. The work originated from attempts
to prove that light was a form of electromagnetic waves...
 Before the advent of companies like Sam's
Technical Publishing information packets, it was often impossible to obtain schematics
and service information from manufacturers unless you were a certified service shop
and/or dealership. In response to many inquiries from Radio-Craft magazine's
readers, publisher Hugo Gernsback queried the
top manufacturers of the day to determine their policies for distributing such
data. Unlike the last couple decades, procuring service information on commercial
products could be very time consuming, and often resulted in not even obtaining
what you needed. Thanks to the Internet being populated with schematics and mechanical
drawings for seemingly everything ever made, we no longer need to call or mail order
for information needed to repair your radio, television, cellphone, lawn mower,
toaster...
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes, and has quickly grown into a major designer and manufacturer with volume
production capacities. Our
WMC-0.5-20-30dB-S is a wideband 30 dB power coupler is a wideband 4-way
in-line power splitter covering 500 MHz to 18 GHz with very good return
loss, low insertion loss, and high isolation performance. The device covers military
bands C through J (upper UHF band, L, S, C, X, Ku, and K bands), delivering much
value to the program. No Worries with Werbel!...
 A lot of the guys I knew from my time in
the U.S. Air Force as an Air Traffic Control Radar Repairman (AFCS 303x1) went to
work for the government or defense contractors after separation. Many were retirees,
so they were (are) collecting military retirement pay on top of really good pay
doing field service work. At this point, probably most of those guys are now doubly-retired,
and collecting Social Security. They're living pretty well these days, probably
with nice homes paid off long ago. 1957, the year this solicitation for
field engineers appeared in Popular Electronics magazine, was right
at the end of the Korean War, and only a decade after World War II. A lot of
new equipment was designed and delivered...
 While working as an electronics technician
at the Oceanic Division of Westinghouse in Annapolis, MD, in the 1980s, I received
a vintage 1941 Crosley model 03CB console style radio for Christmas from Melanie.
It was in poor condition, having spent the previous few decades sitting in a barn
on the Eastern Shore of Maryland. Due to the era of manufacture, vacuum tubes rather
than transistors provided all the necessary amplification. One of the engineers
I worked for at Westinghouse (Mr. Jim Wilson, engineer extraordinaire)
was a Ham radio operator and had been from boyhood in Pittsburgh, PA. After learning
of my Crosley, he gave me his
B&K Dyna-Quik Model 650 tube tester for use in restoring the
radio. The Model 650 was a rather high-end portable tube...
 "Firefly Aerospace's Blue Ghost Mission
2 with the LuSEE-Night radio
telescope aboard will attempt to become the third successful mission to land
there. The moon's far side is the perfect place for such a telescope. The same RF
waves that carried images of Neil Armstrong setting foot on the lunar surface, Roger
Waters's voice, and hundreds of Ned Potter's space and science segments for the
U.S. broadcast networks CBS and ABC interfere with terrestrial radio telescopes.
If your goal is to detect the extremely faint and heavily redshifted signals of
neutral hydrogen from the cosmic Dark Ages, you just can't do it from Earth..."
 In the early days of television, what we
today refer to as cathode ray tubes were called
kinescopes. The kinescope on the receiving end displayed images generated
by a tube called an iconoscope on the transmission end. Kinescopes had round faces
onto which a rectangular picture was electronically drawn. Once manufacturing technology
evolved sufficiently, it became possible to make them rectangular in order to save
on material and to fit a larger picture in a smaller area. The real story as told
in this 1947 Radio News magazine article from my perspective is appreciating the
ingenuity of the manufacturing engineers for an ability to develop machines that
handle very complex operations. They were wonders of electromechanical manipulation.
Oh, and I learned a new word - "lehr"...
 This Radio Service Data Sheet for the
Sparton Model 40 6-Tube T.R.F. Automotive Receiver is an example
of the dozens of similar schematic and alignment instruction sheets that have been
posted on RF Cafe over the years. Obtaining technical information on most things,
even readily available items, prior to the Internet era was often very difficult
- if not impossible. Service centers had what was need provided by manufacturers
and distributors, but if you wanted to find a part number or service data on a refrigerator,
radio, lawn mower, garage door opener...
 Here is a great primer on the operation
of
traveling wave tubes (TWT). A controversy exists over who first invented the
TWT - Bell Telephone Labs' Dr. Rudolf Kompfner, or Andrei Haeff while at the Kellogg
Radiation Laboratory at Caltech. Regardless of its provenance, the device was a
major advancement in the development of high power microwaves. A TWT amplifies broadband
microwaves continuously: an electron gun emits a high-speed beam through a vacuum
tube, interacting with the weak input signal propagating along a helical slow-wave
structure. The helix slows the signal's phase velocity to sync...
 Take a break from workaday drudgery by trying
your hand at this week's
Amateur Radio crossword puzzle. Every word in the RF Cafe crossword
puzzle contains the usual collection of science, math, and engineering terms, and
also includes special words related to Amateur Radio (clues labeled with asterisk
*). There are no generic backfill words like many other puzzles give you, so you'll
never see a clue asking for the name of a movie star or a mountain on the Russia-China
border. 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. Enjoy.
 "Advanced threats lead to open architecture
approaches and new
analysis of electronic countermeasures. Over the past decade, preeminent countries
involved in major military conflicts mainly focused on asymmetrical warfare - surprise
attacks by small groups armed with modern, high-tech weaponry. During that same
period, however, near-peer adversaries began attaining impressive electronic warfare
(EW) capabilities. As a result, a plethora of new, dynamic threats flooded the EW
spectrum, pushing threat detection and analysis to keep pace. Large military forces
must now engage in ongoing..."
 Here are a couple more electronics-themed
comics from Electronics World magazine, good for winding down the week.
They appeared in the January 1963 issue. The page 86 comic reminds me of the professor
I had for solid state circuit design. He was supposedly the first person to successfully
use gallium arsenide (GaAs) as a semiconductor, although he also did pioneering
work with silicon. Anyway, Prof. Anderson would say he takes at least one "business"
trip each year to Portugal in order to search for higher quality raw semiconductor
material in sand on the beaches. He spoke Portuguese, BTW. The page 89 comic is
reminiscent of the pre-GPS days of navigation. Raise you hand if you ever drove
around utterly lost while looking for an off-the-beaten-path location...
|
 • Amazon Leo
Asks FCC for
Satellite Launch Extension
• FCC Gives
Amazon OK for 4,500 More Satellites
• China
Memory Producers Race to Exploit Shortage
• U.S.
Manufacturing Sector Returns to Growth
• ARRL
Student Coding Contest $25k Award
• Shielding
Electronics Supply Chain from Cyberthreats
 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.
 Here is a timeless subject for anyone routinely
subject to exposed high voltages. Most RF Cafe visitors already know that technically,
it is the amount of electric current through the body that determines severity of
electric shock, not the voltage. However, we also know that voltage
does play a role because a certain voltage, per Ohm's law, is needed to induce
a commensurate current. The body's resistance is determined primarily by perspiration
(salt and water) and the path between contact points (e.g., across adjacent skin
areas or hand-to-hand via the heart). MIL-STD-883 and JEDEC* have decided that the
proper Human Body Model (HBM) for testing semiconductor...
 Here is the last engineering- and
science-themed crossword puzzle for June. These custom-made crosswords are done
weekly for the brain-exercising benefit and pleasure of RF Cafe visitors who are
fellow cruciverbalists. The jury is out on whether or not this type of mental challenge
helps keep your gray matter from atrophying in old age, but it certainly helps maintain
your vocabulary and cognitive skills at all ages. A database of thousands of words
has been built up over the years and contains only clues and terms associated with
engineering, science, physical, astronomy, mathematics, chemistry, etc. You will
never find a word taxing your knowledge of a numbnut soap opera star or the name
of some obscure village in the Andes mountains...
 This RF Cafe
Engineering & Technical Headlines Crossword Puzzle contains
at least 10 words from headlines posted on the homepage during the week of August
19 through August 23, 2019 (marked with an asterisk*). These custom-made engineering
and science-themed crossword puzzles are done weekly for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. Every word and
clue - without exception - in these RF Cafe puzzles has been personally entered
into a very large database that encompasses engineering, science, physical, astronomy,
mathematics, chemistry, etc. Let me know if you would like a custom crossword puzzle
built for your company, school, club, etc. (no charge)...
 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...
 I frequently refer to magazine editor, inventor,
author, and futurist Hugo Gernsback as a genius who accomplished as much in his
lifetime as just about anyone has. He often noted in his magazines, including as
in the 1945 issue of Radio-Craft, where products, methods, and events he
predicted ended up coming true. It might seem like a case of "blowing his own horn,"
so to speak, but the fact is that then, as now, you have to publicize your successes
because competitors and those who wish to cause you harm will not do it for you.
Here, he had described a year previous a "Radio
Bomb" which had the capability of radio controlled guidance, including onboard
navigation for pinpointing targets in the final phase of flight. An onboard transmitter
provided telemetry enabling tracking and correction...
 I have often stated that some of the most
enthusiastic and capable engineers and technicians I have had the honor working
with were Hams. As evidenced by this ad in the February 1941 edition of QST
magazine, heads of corporations hold the same view. None other than the president
of Zenith Radio Corporation, Mr. E.J. MacDonald, Jr., thought enough of the talent
residing within the amateur radio community to appeal directly to them with this
full-page ad titled, "Amateurs - Your Thoughts May Be Worth Money." What makes this
advertisement even more interesting is that it specifically wanted Hams with ideas
about the newfangled thing called Frequency Modulation...
 This week's
crossword puzzle for October 9th sports an electronics theme. 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. Enjoy!
 Whenever you see an article with "The Truth
About..." in the title, the expectation is the author is going to reveal some aspect
about the subject that has been kept from public knowledge by nefarious schemers,
or a common misconception is going to be cleared up for the unwitting majority.
This 1952 QST magazine article comes closest to the later category, although
it is not really clear to me after reading it what the newly revealed "truth" is
- maybe just that the effort required for using a vertical antenna at fairly long
wavelengths is worth it because of low radiation angles that facilitate local area
and relatively nearby communications. A lot of really good information is presented
regarding
vertical antenna field patterns, antenna installation, and feedline systems...
 "Mobile
telephone equipment installed in the trunk of the car takes up relatively little
space, is out of the way." That sentence seems really strange in today's world of
pocket-size mobile phones, but it was a big (literally) deal in 1957 when this article
appeared in Popular Electronics magazine. If you are getting old (but not old yet)
like me, you'll remember the prime time TV show called Mannix, where crafty private
eye Joe Mannix had a "futuristic" Motorola car phone in his convertible. Today,
the only kind of radio you are likely to find installed in a car trunk is a high-power
Ham rig. Two-way messaging was a big deal before the advent of cellphones. Service
trucks were dispatched by operators at the home base. As an electrician back in
the 1970s, most of the trucks I operated from had a two-way radio for directing
workers to job sites. I did a lot of troubleshooting and old work (adding circuits
and equipment to existing establishments, as opposed to new construction work...
 This installment of the multi-month series
of articles on antenna principles covers
directional arrays for 300 MHz and higher. Keep in mind that in 1947 when
this appeared in Radio-Craft magazine, wavelengths of a meter or less were
considered to be at the upper end of the operational range. Parabolic reflector
antennas were the domain primarily of ground-based installations due to the physical
size and weight being prohibitive in airborne platforms, and even then they were
rarely used at the time. Most ground and airborne installations were composed of
dipole antennas with various configurations of reflector and director elements for
desired gain and directivity characteristics. Special applications like for direction
finding and longer wavelength radio communications used loop and long wire antennas,
respectively. Highly directive dipole...
 Hugo Gernsback, ever the prolific author
on futuristic technology of the wireless nature, proposes here in a 1944 issue of
Radio-Craft magazine a new form of sea-faring weapon that would project
an practically unstoppable assault on enemy ships: a high speed,
remote controlled torpedo. After being launched from the safety of a location
far out of range of enemy fire, a human controller in an airborne platform (i.e.,
an airplane) would, using navigation advice provided by spotter aircraft (forward
air control in modern terms), steer the explosive craft over potentially long distances
to direct hits on battleships, destroyers, landing craft, patrol boats, etc. Fortunately
for all involved (well at least for Allied nations), the war would only last another
year and a half by the time this concept was published so it did not come to fruition
in time to test...
 This week's
wireless engineering-themed crossword puzzle, as is the case every
week, contains only words pertaining to science, engineering, amateur radio, physics,
mechanics, mathematics, etc. Making a special appearance is the name of the most
recent company to support RF Cafe through advertising. You will see their banner
graphical ad appearing in the right page border sometime this week ...
 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...
 Until the last couple decades, people of
the world recognized and called out evil by name when it reared its ugly head. Except
for subversive imbedded agents, media outlets - radio, television, print, speeches,
etc. - openly and vigorously condemned and attacked the enemy of its country's traditional
way of life. The theme ran deep and wide in news reports and in magazine features.
This advertisement for Air Adventures magazine which appeared in early 1940s
Radio News magazine is an example. In the place of politically correct
speech that doesn't dare to offend an entity which openly and maniacally seeks to
kill you we had the vast majority of media promoting nationalism and patriotism
in order to defeat the enemy. As with just about everything, eBay is a good source
of these vintage Air Adventures magazines. This particular publication only
ran for three editions. However, there were plenty of other titles that featured
stories of heroic adventures against the Nazi scum ;-) Flying Aces magazine...
 Audio crossover networks have the same fundamental
mission as RF multiplexer filters in radio systems, which is to separate and steer
specific bands of frequencies into two or more signal paths. While simple in concept,
implementation in hardware can be a major challenge depending on requirements for
channel separation, feedthrough, phase and group delay, amplitude equalization,
distortion, and other factors. This article discusses some of the decisions used
by crossover network designers when considering where to make band breaks, while
leaving actual circuit design rules to other authors. I built a set of custom speakers
many moons ago and went through the frustrating process of deciding where to place
the breaks and which speakers to use...
 Have you ever heard of a 'globar' resistor? They have been around since the early days
of radio and were used, among other things, to protect vacuum tube heater elements
from burning up due to high inrush current when first turned on. Globars have a
negative temperature coefficient (NTC) of resistance so that, opposite of standard
carbon and metal film type resistors, they exhibit a higher resistance when cold
than when hot. Mac and Barney discuss their use in this episode of "Mac's Radio
Service Shop." You might be more familiar with the name 'thermistor' for such devices,
but globars are unique elements in that their construction from non-inductive ceramic
material makes them useful at high power levels and high frequencies...
 This is just one of many full-page advertisements
in the December 1950 issue of Mechanix Illustrated magazine for
electronics service schools. There was also Coyne Electrical & Television-Radio
School, De Forests' Training (yes, THAT de Forest), deVry Institute, and
a couple others. Electronics for home and industry was big business following World
War II, both from the enormous amount of new knowledge gained in components,
circuits, and manufacturing, and from the near total lack of consumer products being
turned out by manufacturers while wartime rules mandated that all available resources
be dedicated to the effort. In fact, immediately after the end of the war, aircraft,
electronics, automobile, and many other industries went into a major downturn as
government contracts were pulled overnight, leaving companies high and dry with
no orders and factory floors which had been reconfigured to meet government demands.
Of course those companies and employees enjoyed handsome profits and all the work
they could handle for half a decade, so they couldn't complain too much...
 A well-laid-out and routed chassis, control
panel, equipment rack, or circuit breaker panel has always invoked the same sort
of appreciation and awe in me that a Rembrandt painting invokes in an art cognoscente
or a Beethoven concert invokes in a music aficionado. Many moons ago when I worked
as an electrician, I prided myself in obsessively neat and orderly runs of conduit
and Romex™ cable (with no twists), squarely mounted receptacle and switch boxes,
and rigid compliance with NEC requirements. Once I entered into the RF and microwave
realm, an entirely new kind of eye candy appeared in the form of
semi-rigid coaxial cable and waveguide runs. Knowing the technical (electrical)
requirements and limitations based on power, wavelength, and VSWR concerns served
to enhance the appreciation. Electrical wiring has its own unique requirements for
bend radii, enclosure fill, and voltage levels, due to heating, mechanical stress,
and voltage induction issues. RF transmission media adds to that signal reflections
due to contamination and cross-section perturbations, dissimilar junction spurious
mixing products, microphonics, common mode currents... |
