I have written
before about the love-hate relationship a lot of the buying public had with
television and radio repair shops and repairmen - similar to car owners and
mechanics. Lots of jokes and skits (what today is termed a "meme") were created
back in the heyday of in-home entertainment to make light of the situation.
These four
electronics-themed comics from a 1962 issue of Radio-Electronics
magazine are typical examples. The one from page 111 alludes to an issue that
would almost never be seen today on a TV, unless maybe the AC power supply was
on the fritz. A composite analog broadcast signal contained vertical and
horizontal sync[ronization] components which...
"Electrostatic
discharge (ESD) protection is a significant concern in the chemical and electronics
industries. In electronics, ESD often causes integrated circuit failures due to
rapid voltage and current discharges from charged objects, such as human fingers
or tools. With the help of 3D printing techniques, researchers at Lawrence Livermore
National Laboratory (LLNL) are 'packaging' electronics with printable elastomeric
silicone foams to provide both mechanical and electrical protection of sensitive
components. Without suitable protection, substantial equipment and component..."
Mr. Bob Davis, a seemingly endless
source of little known and/or long forgotten
historical radio and television
technical trivia, apprised me of this short segment from the 1960s Dragnet
television series, starring Sgt. Joe Friday. It features a guy, who turns out to
be a ... well, I won't spoil it for you ... who proudly professes his thirty
year career as a radio repairman. "...started back in the days of the old Crosleys, Atwater-Kents, Farnsworths.
Those were real radios, well built, well designed. Nothing cheap about any of
them. They didn't have transistors in those days, just tubes as big as light
bulbs. That meant heavy chassis, heavy transformers, and we didn't fix them by
simply slapping in a new part, either. We fixed the old parts. I wish...
A new word has been added to my personal
lexicon: "sphenoidal."
Author John Kraus used it to describe the wedge shape of a
corner reflector. The Oxford Dictionary defines "sphenoid" thusly: "A compound
bone that forms the base of the cranium, behind the eye and below the front part
of the brain. It has two pairs of broad lateral "wings" and a number of other projections,
and contains two air-filled sinuses." This "square corner" configuration - essentially
a "V" shape, is shown to exhibit up to 10 dB of gain while being relatively (compared
to a parabolic reflector) insensitive...
Albert Einstein's general theory of relativity,
published in 1915, fundamentally reshaped the way scientists understand gravity,
space, and time. It extended his 1905 special theory of relativity, which described
how the laws of physics are consistent for all observers in uniform motion and how
light's speed is constant in a vacuum. However, the special theory did not address
accelerating reference frames or gravitational forces. Einstein's general theory
tackled these limitations by proposing that gravity is not a force in the traditional
sense, but rather a curvature of spacetime caused by mass and energy. This profound
insight would alter the course of 20th-century physics, influencing cosmology, black
hole theory...
"The growing use of artificial intelligence
(AI)-based models is placing greater demands on the electronics industry, as many
of these models require significant storage space and computational power. Engineers
worldwide have thus been trying to develop neuromorphic computing systems that could
help meet these demands, many of which are based on memristors.
Memristors are electronic components that regulate the flow of electrical current
in circuits while also 'remembering' the amount of electrical charge that previously
passed through them. These components could replicate the function of biological..."
Reading through the news items in the vintage
electronics magazines provides a mixture of important historical facts and figures
along with some predictions on the future of the industry. Some of the predictions
turn out to be amazingly accurate, even though in retrospect they might seem obvious.
Take, for example, Sylvania VP Dr. Robert Castor's foresight about how, "the future
growth of the semiconductor industry lies in a major switch from the production
of individual components to solid-state subsystems that can be used as building
blocks in electronic designs." "Well of course," you might be temped to say; however,
at the time there were still significant hurdles to overcome related to material
purity, wafer size, photolithography...
Reactel has become one of the industry leaders
in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They
offer the generally known tubular, LC, cavity, and waveguide designs, as well as
state of the art high performance suspended substrate models. Through a continuous
process of research and development, they have established a full line of filters
of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more.
Established in 1979. Please contact Reactel today to see how they might help your
project.
2012 came and went more than a decade ago.
The date was 50 years in the future back in 1962 when Radio-Electronics
magazine editor Hugo Gernsback asked industry leaders to cogitate on possibilities
of the
state of electronics in 2012. Let's see how they did. One guy predicted our
communications would be in the 100 THz to 1,500 THz band, using 2 decimeter
antennas. Nope. Another believed we would be communicating with aliens on a regular
basis. A military dude partly hit the mark by predicting 2- and 3-year-olds would
be sitting in front of "televideo screens" (cellphones) learning Esperanto and "other
basic studies." Bell Labs believed most audiovisual material, along with commerce,
would be done electronically; i.e., the World Wide Web. I'm not quite sure how to
interpret the IT&T guy's prediction of replacing microwave space transmission
with light wavelength waveguide transmission. Seems bassackward to me...
Here is a unique approach to discouraging scam
callers. A lot of scam calls are themselves AI, so can one AI detect and aviod another?
"Gangster
Granny! Meet Daisy: O2's new weapon against scammers. O2 has unveiled its new,
unique weapon in its fight against scammers: Daisy, an AI-powered assistant designed
to keep fraudsters talking and waste their time. As part of Virgin Media O2's 'Swerve
the Scammers' campaign, Daisy's mission is to distract scammers with realistic,
rambling conversations, helping protect potential victims while raising awareness
about fraud. Her lifelike conversations, peppered with stories about family or hobbies
like knitting, have kept fraudsters on the line for up to 40 minutes..."
Albert Einstein's
special theory of relativity, a milestone in physics, transformed our understanding
of space, time, and energy (mass). The theory, published in 1905, stemmed from Einstein's
efforts to resolve inconsistencies in classical physics, specifically between Newtonian
mechanics and electromagnetism as formulated by James Clerk Maxwell. By reconceiving
space and time as interconnected and relative to the observer's frame of reference,
Einstein established a framework that had profound implications for science and
technology. To understand how this groundbreaking idea emerged, one must consider...
Werbel Microwave's Model WM2PD-0.5-26.5-S
is a wideband 2-way in-line power splitter covering of 500 MHz to 26.5 GHz with
excellent return loss, low insertion loss, and high isolation performance. With
ultrawideband performance, amplitude balance is typically 0.24 dB and phase
unbalance is typically 2.6°. Insertion loss is low for the bandwidth, coming in
at a typical 1.2 dB above 3 dB splitting loss. Return loss 16 dB
typical. Isolation 18 dB typical. The device is precision-assembled and tested
in the USA...
If you wanted a career as an
electronics technician at the end of World War II, the world was your oyster
- so to speak. Electronics and communications trade magazines and publications like
Mechanix Illustrated and Popular Science ran a plethora of ads
monthly that offered unlimited opportunity to men seeking a career servicing the
burgeoning market of postwar technological marvels. Even though the enclosures were
not yet being marked with "No user serviceable parts inside," that fact was most
people were not qualified - nor did they want - to monkey with the guts of radios,
televisions, and other household appliances... (I provide a simulation to show the
true zener diode circuit output)...
Take time out of your busy workday to look
at these three
electronics-themed comics from the February 1962 issue of Radio-Electronics..
The page 32 comic reminds me of sometime in the late 1970s while working as
an electrician (prior to enlisting in the USAF) when I was doing side jobs, and
a guy had me wire up a receptacle for his big 25" screen (CRT) which he had mounted
in a wall, with the chassis sticking out the back. It was in an upstairs room in
a Cape Cod style house with lots of room behind the wall. He was a "man cave" pioneer
with a full suite of high quality audiovisual equipment - even a Betamax machine!
The page 81 comic exhibits the irony that would have existed in the day if
American-made electronics equipment had been promoted in Japan, which they probably
were not. In 1962, Japanese...
Admittedly, I mostly posted this because
of the drawing. "While
direct-to-cell (D2C) satellite communications were a big topic at the recent
Brooklyn 6G Summit, the technology is already here, well before 6G's anticipated
2030 arrival. Apple and Google already offer D2C emergency messaging, and Starlink,
T-Mobile and others are anticipated to follow. D2C satellite communications will
be well established when 6G arrives. The 3GPP froze a 5G specification for Non-Terrestrial
Networks (NTN) in Release 17 in March 2022, which means that NTN-compatible chips
and components should be available now or soon. SpaceX has reduced the cost..."
The subtitle of this article from a 1971
issue of Popular Electronics magazine, "From
Quackery to Speculation to Programmed People," could to some extent still be
applicable even though the author evidently meant to put an end to the "quackery"
and "speculation" part of it. Indeed, a lot of advancement has been made in the
fields of electrostimulation of weak or/or paralyzed muscles, healing of certain
types of soft and hard tissues, suppressing sporadic muscle twitching and epileptic
seizures, and other malady diagnosis and relief. Specifically tuned microwave frequencies
have proven useful in healing and symptom relief as well. As with most articles
on medical procedures, I cringe at some...
Anatech Intros 3
Filter Models for November
Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized RF and microwave filters
and filter-related products for military, commercial, aerospace and defense, and
industrial applications up to 40 GHz. Three new
C-band cavity bandpass filter models have been added to the product line, including
a 4994 MHz BPF with a 50 MHz bandwidth, a 4950 MHz BPF with a 10 MHz
bandwidth, and a 5785 MHz BPF with a 100 MHz bandwidth. Custom RF power
filter and directional couplers designs can be designed and produced with required
connector types when a standard cannot be found, or the requirements are such that
a custom...
• 5G
Is 42% of Fixed Wireless Access (FWA) in 2024
• Robert Dennard,
DRAM Pioneer, Dies at 91
• TSMC's Energy
Demand Drives Taiwan's Geopolitical Future
• Semiconductor
Packaging Market on 5.6% CAGR 'Till 2028
• Altering
Asteroid Trajectories with Nuclear X-Rays
Albert Einstein, one of the most renowned
physicists in history, was born on March 14, 1879, in Ulm, in the Kingdom of Württemberg,
part of the German Empire. His father, Hermann Einstein, was an engineer and salesman
who ran an electrochemical factory, and his mother, Pauline Koch, managed the household
and supported her son's education. Einstein had one sister, Maja, who was born in
1881 and with whom he had a lifelong close relationship. Einstein's extended family
included several relatives who would play various roles in his life, both personally
and professionally. His early family life was comfortable, though his parents moved
frequently as they sought economic stability. Hermann Einstein's business ventures
had varying success, and eventually, the family moved to Italy in 1894...
Here is the second part of a series of articles
about
stepping switches appearing in 1967 issues of Radio-Electronics magazine.
A standard (at the time) dial rotary phone was used as a familiar example in the
part one. It delivers a single pulse for each number / letter set from 1, 2 (ABC),
3 (DEF), through 9 (WXY), 0 (Operator). On some phones, you can hear the clacking
of the switch contacts as the spring-loaded dial rotates from the selected number
back to home position. The stepping action as the result of dialing occurs at the
telephone system switching and call routing equipment at central locations. There,
stepping switches increment with each pulse received, and when the full number of
pulse sets have arrived, the circuit is complete and the call put through to ring
the phone...
"Results are published, and the numbers
are in. They paint a picture of a very active
2024 ARRL
Field Day. Nearly 1.3 million contacts were reported during the 24-hour event.
That is up from 2023's 1.25 million contacts. That's likely indicative of the continued
rise of Solar Cycle 25 leading up to the event, but more people also participated
this year. Entries were received from all 85 ARRL and Radio Amateurs of Canada (RAC)
sections, as well as from 27 different countries from outside the US and Canada.
'It is encouraging to see a rise in participation year to year,' said ARRL Contest
Program Manager Paul Bourque, N1SFE. 'ARRL Field Day is amateur radio's premier
event, and the hams turned out for it..."
After searching for the first mention of
Nikola Tesla in U.S. newspapers, I performed a similar search on
Albert
Einstein, again using editions available in the NewspaperArchive.com database.
I was utterly surprised to find it in a 1919 issue of the The New York Times.
His theory of Special Relativity was published in 1905 and his theory of General
Relativity was published in 1915, so it took The NY Times four years to
mention it. There is a reference to Dr. Einstein's' work on relativity in a 1915
edition of The Manitoban, from Winnipeg, Canada. The NY Times article
is an actual interview with Albert Einstein, wherein at one point it is stated that
there were perhaps only a dozen people in the world at that time who understood
general relativity. Interestingly, Einstein uses the term "difform motion" to describe...
Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to announce
the model
AMP2103P-LC, dual-mode (CW & pulse) amplifier covering 800 to 3200 MHz.
1000 watt peak pulse power, or 500 watts CW. Ideal for automotive pulse/radar
EMC-testing & commercial applications. Pulse widths to 560 μsec, duty cycle
to 10%, 60 dB gain, and outstanding pulse fidelity. Monitoring parameters for
forward/reflected power in watts and dBm, VSWR, voltage, current, and temperature,
with unprecedented reliability and ruggedness in a compact 7U chassis...
Sally Mason was the soldering iron-wielding
heroette (heroine sounds too much like the narcotic) of Nate Silverman's "Sally,
the Service Maid" series that ran in Radio-Craft magazine during the
years of World War II. As I noted in the previous episode, many of the nation's
women were left behind to run their husband's, father's and/or son's electronics
sales and repair businesses when they went off to save the world from aggressive
Communists, Socialists, Maoists, Nazis, and other nasty types. Some of those ladies
had already become very adept at troubleshooting, component replacement, and aligning
radio and television sets, while some were left to learn at the School of Hard Knocks.
Sally's father, Gus Mason...
Crane Aerospace & Electronics' products
and services are organized into six integrated solutions: Cabin Systems, Electrical
Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions,
and Sensing Components & Systems. Our Microwave Solution designs and manufactures
high-performance
RF, IF and millimeter-wave components, subsystems and systems for commercial
aviation, defense, and space including linear & log amplifiers, fixed &
variable attenuators, circulators & isolators, power combiners & dividers,
couplers, mixers, switches & matrices, oscillators & synthesizers.
The AN/MPN-13|14 mobile radar system I worked
on while enlisted in the U.S. Air Force was designed and fielded around the time
this
Electronic Navigation in Flight article appeared in a 1962 issue of Radio-Electronics
magazine. It had been upgraded a few times by 1979 when I was in Air Traffic Control
Radar Repairman technical school at Keesler AFB, Mississippi; however, the original
system did not featured a Doppler capability. The fully RF analog system could not
provide air traffic controllers with speed data, but it did use physical mercury
delay lines to provide a stationary target (ground, and to some degree, rain, clutter)
cancellation by inverting and summing a real-time radar...
Decisions, decisions, decisions. As the
title states, color television manufacturers were, in 1965 when this Electronics
magazine article was published, finding themselves between a rock and a hard place,
as the saying goes, regarding a change
from vacuum tubes to transistors. The buying public (aka consumers) had mixed
emotions about the newfangled semiconductors based at least partly on bad information
about transistors. Transistors had been designed in various circuits for a decade
and a half and were gaining rapidly in performance and reliability. The price was
coming down, but as reported here, still cost $5 to $10 apiece compared to a $1
vacuum tube. Company management needed to decide whether to delay implementing the
new engineering and production methods required to deal with transistors...
"At 8:30 p.m. on 16 May 1916, John J. Carty
banged his gavel at the Engineering Societies Building in New York City to call
to order a meeting of the American Institute of Electrical Engineers. This was no
ordinary gathering. The AIEE had decided to conduct a live national meeting connecting
more than 5,000 attendees in
eight cities across four time zones. More than a century before Zoom made virtual
meetings a pedestrian experience, telephone lines linked auditoriums from coast
to coast. AIEE members and guests in Atlanta, Boston, Chicago, Denver, New York,
Philadelphia, Salt Lake City, and San Francisco had telephone receivers at their
seats so they could listen..."
|
For many years I have been scanning and posting
Radio Service Data Sheets like this one featuring the
Admiral "Aeroscope" 161-5L, 162-5L, and 163-5L Midget Set models which appeared
in a 1939 issue of Radio-Craft magazine. There are still many people who restore
and service these vintage radios, and often it can be difficult or impossible to
find schematics and/or tuning information. Some websites offer to sell this information,
but often what is shown here is enough to get an old radio working again since most
times both schematics and alignment steps are included. I keep a running list of
all data sheets to facilitate a search...
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...
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...
Thyratrons, klystrons, and magnetrons I've
heard of, but
trochotrons, charactrons, tonotrons I ain't heard of. That made this quiz more
of a learning exercise for me than a test of any sort of knowledge possessed. Heck,
I thought an 'ignitron' was a pejorative term for a really dumb techie wannabe.
In all there are 17 types of '-tron' devices given for which to match from a list
of descriptions. You'll probably do better than I did on this quiz that appeared
in the October 1963 issue of Electronics World magazine.
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers"
Smith chart design. These would make excellent gifts for husbands, wives, kids,
significant others, and for handing out at company events or as rewards for excellent
service. My graphic has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. I only make a couple bucks
on each sale - the rest goes to Cafe Press. It's a great way to help support RF
Cafe. Thanks...
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...
In this article from a 1942 issue of
QST magazine, author T.A. Gadwa employs a
standing wave mechanism analogy that I don't recall having
read before - that of a dam on a river. The river is the transmission line with
a lake as the source (presumably) and then he imagines a dam load. The dam
standing waves, per his description, have phase and amplitude characteristics
that depend on how tall the dam wall is relative to the surface height of the
dammed river. An extensive array of graphs is provided showing how the current
of the dam standing waves react to the dam transmission line termination
impedance. I always wonder when seeing electrical-mechanical parity examples
whether, as with this case, there are any dam magazine articles out there that
use an electrical transmission line to help fellow civil engineers...
Around the time this article was written,
the first wave of the solar and wind (which essentially is also solar) power generation
craze was settling in. A few small windmill generators popped up around where I
lived in the Annapolis, Maryland area, but they were mostly owned by hippie Earth
worshipers who eschewed modern conveniences and didn't need hot water for bathing
anyway. Most of that generation (pun intended) of windmills put out direct current
(DC - typically 12 or 24 volts) rather than tying in with the AC line power, and
required separate electric wiring in the house. People used appliances and light
fixtures designed for recreational vehicles. We knew a very nice older man and his
wife who lived "off the grid" and grew most of their produce and even kept a goat
for milk (they were clean people). They had some
photovoltaic (PV) solar cells to supplement the windmill...
"YL" is the shorthand used by amateur radio
operators when referring to female operators -
Young Lady.
Although still chosen as a hobby in larger number by men, ladies have long been
avid participants in the art/science of Ham radio. The American Amateur Radio
League's QST magazine devoted this "YL News and Views" column to their
contributions many years ago - trendsetting in its day. This particular issue
introduces Louise Ramsey Moreau as its new editor. Her interest in Ham radio was
piqued when she realized "all the women heard on their receivers were not 'just
wives,' but licensed operators." The rest, as said, is history...
When you read a lot of tutorials about
introductory electronics on the Internet, most are the same format
where stoic, scholarly presentations of the facts are given. Those of you who don't
have enough fingers and toes to count all of the college textbooks like that which
you have read know of what I speak. When hobby articles are written in a similar
fashion, it can quickly discourage the neophyte tinkerer or maybe even a future
Bob Pease. QST has printed a plethora of articles over the years that are
more of a story than just a presentation of the facts. My guess is the reason is
because often the authors are not university professors who have forgotten how to
speak to beginners. This article on basic calculations for AC series and parallel
circuits is a prime example...
If you have not yet discovered the Engineering
and Technology History Wiki (ETHW) website, now would be a good time to surf on
over and take a look at the vast resources there - particularly the "Oral-History"
series of in-person interviews of our field's top scientists and engineers. Among
them are Dr. Harold Beverage, Dr. Ulrich L. Rohde (N1UL), Harold S.
Black, Harold A. Wheeler, Dr. Irwin Jacobs and Dr. Andrew Viterbi,
and of particular significance to me,
Dr. David B. Leeson (W6NL), founder of California Microwave and Ham
radio contesting champion. Many of the oral interviews were conducted in the pre-Internet
era and some of the people are no longer with us. A few days ago, I had the honor
of being contacted Dr. Leeson as part of his search for information he wants
for some work he is doing. His name is familiar to amateur radio contesters who
participate in DX (long distance) events. Most Hams do their part from home-based
"shacks" while others join in during Hamfest gatherings. Some adventuresome and
hardy souls set up temporary (and sometimes fixed) stations in remote locations
around the world in order to provide rare and exotic contact opportunities, where
coveted QSL cards can be collected...
As a long-time Paul Harvey fan, I used to
listen to his radio news broadcasts and especially looked forward to his "The Rest of the Story"
pieces. It was a challenge to listen and try to figure out who or what the alluded-to
person, place, or thing at the end of the the story would be. In honor of Mr. Harvey,
who left this Earth in 2009, the following Smorgasbord about featured celebrity
"Sam" is fashioned after his trademarked style. As is often the case with people
of accomplishment, this subject's talents extended beyond the skill for which he
is most known. An article in the September 2011 Smithsonian magazine inspired the
research ...
Whereas this "Choosing
the Right Antenna" from a 1958 issue of Radio & TV News magazine
article concerns television antennas, the information applies generally for any
application. Folded dipoles, conicals, Yagis, log periodic, and other types were
used by homeowners sometimes desperate to receive a good signal from a far away
broadcast station or from a location buried in obstacles (terrain, buildings, water
bodies, automobiles, towers, etc.) blocking and reflecting otherwise strong signals,
thus causing fading and multipath degradation. You might think the advent of cable
and satellite TV, along with Internet access, might have removed the need for rooftop
type over-the-air antennas, but it is not so. There are still plenty of people located
in rural areas that struggle to get a good signal, as evidenced by RF Cafe
visitor Dave Jones, (N1UAV) stacked 9- & 17-element yagi TV antenna project...
Most of us
here in America recognize the
Packard Bell name from the line of personal computers they sold in the 1980s and
1990s. I owned three of them, beginning with an Intel 80286 model, then an 80486, and
finally a Pentium model. They were in the "pizza box" format that sat on the desk with
the CRT monitor on top; I always preferred that configuration over the tower type. Before
Packard Bell made personal computers, they made personal radios for the desktop beginning
back in the 1930s. That explains why Mr. J.T. Goode, an engineer with Packard Bell, would
write an article in 1947 regarding a method to tune antennas using light bulbs...
Here is a short tutorial on
resistor-capacitor (R-C) combinations and the time constants created
by their combinations. It's pretty basic stuff, but there are new people coming
into the field of electronics all the time so it is worth posting. Discussed are
coupling circuits, filter networks, differentiators, and time-delay circuits. The
"After Class" feature is a series run by Popular Electronics magazine in
the 1950s and 1960s. As with this installment, "After Class" presented topics on
electricity and magnetism that served not just as new material for beginners, but
was a good review even for seasoned practitioners of the craft ...
Incandescent pilot lights are definitely
a thing of the past; LEDs are the ubiquitous choice these days for obvious reasons
(low cost, low current, long life). Nonetheless, there are still lots of equipment
still in service that do use them. In 1952 when this article appeared in Radio-Electronics
magazine, incandescent (and neon) lamps were standard in test gear, radios, televisions,
tape recorders, record players, kitchen appliances, cars, industrial machinery,
and many other everyday things. Electronics repairmen needed to deal with them on
a regular basis. Although not technically sophisticated, knowing a little something
extra about the little bulbs could be quite handy. One tidbit if useful info in
this article is how the color of the little glass bead that mounted the filament
to the base was often a clue to the current draw of the lamp at nominal operating
voltage...
My long-established collection of
soldering aid and tuning wand tools still gets a fairly regular workout - but not
necessarily for soldering tasks. Because of their purpose-designed ends, they come in
handy for all sorts of model building activities. Most are non-metallic, meant for bending
and poking, and are very strong and heat resistant. The metal types are still required
for direct contact with molten solder. One of the best tips offered in this Electronics
World article is for when replacing a leaded component on a printed circuit board
(PCB). If possible, rather than heating the landing pad and plated through-via to remove
the leads, just clip the leads far enough from the PCB surface to create a post or loop
to solder the new component to...
October 18th's custom
Science and Engineering Technology themed crossword puzzle contains only only
words from my custom-created lexicon related to engineering, science, mathematics,
chemistry, physics, astronomy, etc. (1,000s of them). 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. The technically inclined cruciverbalists amongst
us will appreciate the effort.
This news bit from a 1951 issue of Radio-Electronics
magazine reports on the FCC's declaration of illegality the practice by some FM
broadcasting stations of providing a means for
blanking out commercials and station identification to entities willing to pay
for the special receivers and pay for a subscription. Nobody I have ever known looks
forward to enduring commercials on television or radio (or Internet these days).
The only way most of us could listen to music without interruption was to by a record,
tape, or CD. VHS tapes and DVDs provide some relief from commercials, although even
though you pay for them there are typically promotions for other movies at the beginning.
Commercials on radio and television (and now the Internet) have consumed a larger
part of each hour of programming with each passing year. The DVD collections we
have of 1960s and 1970s Prime Time TV shows average run times of about 54-55 minutes...
As the planet's population grows older and
people have an increasing amount of disposable income and spare time, the opportunity
to engage in nostalgic endeavors has gone up. That includes
collecting, restoring, and operating equipment and peripherals that were the
mainstay of their lives during their halcyon days of youth. In recognition of the
new marketing opportunities, industries are popping up to feed the frenzy. Look
no farther than eBay and the amount of vintage items available for purchase - at
ever increasing prices. Having myself been an eBay buyer of memorabilia from my
early model airplane, model rockets, and electronics hobbies, I have watched prices
soar in many cases. Turntables (aka phonographs, or for the lowbrow types, record
players) are being manufactured again ...
The 1940s and 1950s was an era of much advancement
in our knowledge of Earth's upper atmosphere and its affects on
radio communications - both good and bad as reported by this 1947 issue of
QST magazine. Industry, government, academic, and amateur groups all played
major roles in conducting experiments and publishing findings for the interested
community to share and build upon. Still today a huge amount of research is being
carried out to better understand how the various layers of the atmosphere - from
ground level to space - are affected by extraterrestrial influences. A year ago
I posted an article, along with a bit of editorializing, from the July 1958 edition
of Radio-Electronics entitled..."
Since 2000, I have been creating custom
engineering- and science-themed crossword puzzles 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 ...
Anyone who pays attention in a present-day
high school physics class would read this article from 1944 and immediately appreciate
the advances that have been made in atomic theory during the ensuing 75 years. With
modern knowledge, it is hard to believe that even in 1944 someone would seriously
suggest that theorized
sub-electronic particles (building blocks of electrons) might be responsible
for supporting the propagation of electromagnetic energy. We still consider the
electron to be an elementary particle (although now not so the proton and neutron),
but at this point we are aware of many elementary particles other than the electron
(some of which make up protons and neutrons). There are six types of quarks, the
gluon, the photon, three types of bosons, and five other types of leptons other
than the electron - for a total of 17. The author's characterizing of the electron
as having a "flitting and jerking" "enormous" positional presence...
Images, harmonics of the intermediate frequency
(IF), harmonics of the local oscillator (LO), multiple station IF mixing, inductive
and capacitive coupling, other types of noise can find a way into circuits if sufficient
shielding and judicious component placement is not implemented. It is as true today
as it was in 1941 when this article appeared in Radio-Craft magazine. An
interesting interference generator discussed is that of heterodyned signals generated
external to the receiver by means of random nonlinear junctions reacting to multiple
high power broadcasting stations in a local area, as was fairly common when AM stations
were the norm. Rusty bolted joints in buildings, towers, even automobiles can be
the source of such phenomena. Even today it is not uncommon for bolted and riveted
junctions on antennas and RF connectors to generate what are now termed
passive intermodulation (PIM) spectral products...
Air Route Traffic Control Centers, now using
the acronym ARTCC rather than ARTC as used in this 1960 article, were and still
are the human and computer command and control facilities responsible for safe and
orderly flow of air traffic in the U.S., and a worldwide network of Area Control
Center (ACC) handles everything else in a massive coordinated effort. The advent
of radar during World War II and the ensuing evolution of it and electronic
computers in the following years struggled to keep pace with the equally rapidly
evolving aircraft design and capability. A simple control tower with air traffic
controllers using binoculars and a radio mike could not handle the volume of airplanes
and helicopters traversing the skies and patronizing busy terminals. Many forms
of electronic navigation aids were developed including very high frequency omnidirectional
range (VOR), direction finders (DF) using antenna nulling for finding radials to/from
FM radio transmitter, long range navigation (LORAN)...
The 1950s was a time of transition in the
television watching business. Broadcasters were experimenting with
pay-TV systems to replace or supplement over-the-air service. Much as people
today think that everything on the Internet should be free, the same mindset prevailed
then regarding television programming. Early coding and decoding schemes seem really
hokey by today's standards, using computer-type punch cards. I remember the area
around Annapolis, Maryland, where I grew up, had both over-the-air and cable-based
subscription services in conjunction with the open broadcasts. I spent at least
a little time playing with the horizontal and vertical picture sync settings on
the back of the TV set that, if lucky... |