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
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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..."
|
Although the subtitle of Part V of
the 1949 Radio-Electronics magazine "Microwaves"
introductory series in refers to Special Sections of Waveguide Are Employed as Transformers,
author Palmer is discussing not impedance transformers but physical configuration
transformations. That includes in-between rectangular, circular, and oval cross-sections,
in-between waveguide and coaxial cable, and rotary joints. Signal injection and
extraction via stubs are also covered. He provides a high level introductory description
of how microwave frequency waveguide works without delving into the scary mathematics
required to design the components...
Even though my fingers stop working when
exposed to temperatures below freezing, I love the northern climate - four full
seasons, snow, iced-over lakes, migrating birds, fiery autumns, cool summers, the
whole experience. Having the option of not participating in the cold outdoor environs
is what makes it good. However, the
U.S. Army Signal Corps guys pulling duty in Alaska during World
War II did not have that luxury. As told by radio engineer Major Colvin in
this story from a 1945 edition of ARRL's QST magazine, winter life in Alaska at
-40° was a real challenge. It was a world where Prestone antifreeze froze, the sun
shone only a few hours a day, vehicles had to be left running 24/7 or risk not being
able to be re-started, and mile-long treks between buildings was common. There were
no snowmobiles. The success of the communications station...
Since 2000, I have been creating custom
technology-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 in the Andes mountains.
You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical
location like Tunguska, Russia, for reasons which, if you don't already know, might
surprise you...
Listen to the RF
Cafe Podcast! Hugo Gernsback, a name familiar to anyone who has been reading
some of the vintage electronics articles posted here on RF Cafe over the years,
was never short on ideas - both serious and fanciful. In 1947, when this editorial
appeared in his very popular Radio-Craft magazine, radio had become ubiquitous
in the commercial and consumer worlds, but he laments that the appliance had not
yet received its due compliment of
ancillary devices. Telephone, which had been around even longer that radio,
had a fair market of add-ons like a shoulder rest for the handset, an amplifier
for the hard-of-hearing, remote ringers, etc. There was not yet a selection of similar
devices for the convenience of radio listeners, and here Mr. Gernsback suggested
a few. Big money was to be made on such products. Among them he mentions a couple
humorous ideas like the "Warmeradio," where a chassis with inset...
With today being the anniversary of the end
of WWII (VE Day), this January 1942 article from QST
magazine report on how it affected amateur radio operators helps add context to
the era. It came as no surprise to amateur radio operators that their
operational privileges would be curtailed immediately after the United States
was drawn into World War II following the Japanese Imperial Navy's attack on
Pearl Harbor. After all they were subject to the same kind of restriction during
WWI. Just as President Woodrow Wilson issued an executive order prohibiting
unauthorized transmissions by amateurs, President Roosevelt had the FCC ban the
radio transmissions of Hams. The fear was that enemy intelligence gathering
posts...
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 motivations for doing what I do - that is to help make
useful data available. That is the reason I also scan and post schematics and service
pages for vintage radios...
Beginning in 2000, I have created hundreds
of custom technology-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 in the Andes mountains.
You might, however, encounter the name of a movie start like Hedy Lamarr or a geographical
location like Tunguska, Russia, for reasons which, if you don't already know, might
surprise you...
Prior to news of the A-bombs dropped at the
end of World War II, most people had no idea what nuclear anything was. My
guess is school textbooks made scant mention of it mainly because what was known
of the science was kept under wraps at the Department of War. The Department of
Energy (DoE), which currently administers nuclear policy and oversight, did not
formally exist as a separate entity until 1977. Per their website, "Although only
in existence since 1977, the DoE traces its lineage to the Manhattan Project effort
to develop the atomic bomb during World War II, and to the various energy-related
programs that previously had been dispersed throughout various Federal agencies."
In 1955 when this episode of "Mac's Service Shop" appeared in Radio & Television
News magazine, one of the popular items for electronics hobbyists was Geiger
counters (along with metal detectors)...
Since 2000, I have been creating custom
technology-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 in the Andes mountains. You might, however, encounter the name
of a movie star like Hedy Lamarr or...
Considering that only three-and-a-half decades
had passed since the brothers Wright first flew their eponymous "Flyer" off the
sands of Kitty Hawk, North Carolina, it is pretty impressive to think that by 1938
the majority of commercial air transport planes were under the able control of electromechanical
apparatus(es?). Rudder, elevator, aileron, and throttle, driven by electrical servomechanisms
rather than human hands and feet, responded to the signals to analog computers fed
data from onboard barometer, accelerometer, level, and compass sensors, and from
ground-based radio directional beams. That was for mostly straight and level flight
from one fixed waypoint to another. An ability to program vectored flight paths
came later. This "Radio Lands the Plane" article discusses progress being made in
the realm of completely automated landings. As can be seen, the framework for modern
instrument landings systems was being laid...
Innovation, out-of-the-box thinking has been
responsible for a large part of the world's more successful ventures - ranging from
small-time operators to the corporate and university scale. The "War Years" were
notably difficult for a lot of businesses not directly involved in wartime production
and/or service due to the shortage of supplies and workers. Radio News
magazine and others of the era printed many stories to both inform and encourage
electronics industry participants. This October 1945 story tells of how radio service
and sales shop owner Pat Murphy, of Carthage, New York, devised a system to successfully
tap an otherwise avoided customer base - rural farm and home owners. His scheme
made a lot of people happy and provided a source of income to others as a reward
for facilitating the endeavor. "Reaching
the Ruralist" is a great, short read...
Mac's staff service technician, Barney, asked
a great question when he mentioned that Pittsburgh radio station KDKA made the country's
first commercial broadcast in 1920: "Who
was listening?" It is a reasonable question since prior to the beginning on commercial
radio broadcasts there would have been no reason for there to have been a lot of people
to own a radio for receiving commercial broadcasts. The answer, of course, is that there
were plenty of multi-band radios in homes and businesses for listening in on shortwave
broadcast from around the world - a very popular pastime in the era. Just as today we
are bombarded with admonitions to not stare at computer monitors or cellphone screens
for too long lest we suffer near-sightedness or worse, radio listeners of yore who used
headsets were told, "Youths of this generation will never have as protruding ears as
some of their older brothers." I suppose...
Banner Ads are rotated in all locations
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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...
February 1953 was just a little more than
four years since Messrs. Brattain, Shockley, and Bardeen announced their invention
of the transistor. This full-page advertisement by Raytheon ran in Radio-Electronics
magazine announcing the world's first commercially available
PNP germanium transistors. It was a big deal. Model numbers CK721
and CK722. CK721 handled about twice the collector current (12 mA) as the CK722,
both with collector voltages maxing out at around 8 volts. The introductory
price for the CK722 was $7.60, which in 2018 money is equivalent to $72.27* At that
cost, it is hard to believe they got anyone to replace vacuum tubes with transistors.
Fortunately, economy of scale rapidly brought prices down. Interestingly, CK722
inventor Norman Krim promoted a business...
All
RF
Cafe quizzes would make perfect fodder in employment interviews for technicians
or engineers - particularly those who are fresh out of school or are relatively
new to the work world. Come to think of it, they would make equally excellent study
material for the same persons who are going to be interviewed for a job. This quiz
is based on the information presented in High-Frequency Integrated Circuits, by
Rosin Voinigescu.
Electronics symbols
for schematics and wiring diagrams have remained amazingly consistent for the last
hundred years, although obviously many new ones have been added. You can see from
this set of standardized wiring diagram and schematic symbols from a 1955 edition
of Popular Electronics what I mean. Even symbols for newly introduced devices tend
not to change. There are some variations such as whether or not to draw a circle
around a transistor or how many lightning bolt lines to use with photon emitters
and detectors, but that's about it. The digital world adopted IEEE Standard 91-1984
for logic and microprocessors, although you will still occasionally see variants
in symbols, especially in early digital circuit schematics. The ARRL publishes its
own version of standardized electrical schematic symbols, but even the ARRL
Handbook, in which the symbols are printed, does not strictly conform to its
own standards.
Genius
takes on many forms, not the least of which is the ability to concoct and compose
an [almost] believable a story describing in the utmost detail the technical workings
of a complex mechanical gadget. Items such as a mizule wrench, meta-phasic shielding,
blinker fluid, a left-handed screwdriver, and - one of my favorites - the muffler
bearing, have been heard in comic routines... er... routinely. No matter how many
times you hear them you always laugh again. Some are actually a portmanteau and
just sound funny while others are completely made up. This
Digital Decabulator article that appeared in a 1966 issue of
R/C Modeler magazine is amazing; it pegs the B.S. detector from beginning
to end ...
"Our first complete column devoted to the
subject [of
v.h.f. and u.h.f. signal variation], presenting material similar to that which
follows, was withheld from publication at that time in compliance with censorship."
That is an amazing statement from a time when almost any form of technical information
that was not already public knowledge was withheld for the sake of the war effort.
Nothing that might even remotely give the enemy an edge, and consequently possibly
harm our troops, got past the government censors at the War Department. Most citizens
and even media editors willingly complied. Compare that with today's 5th column
traitors at most of the media outlets that not only can't wait to publish information
that will aid and abet our country's enemies, but have been known to manufacture
stories in order to make the U.S. look bad...
Prior to the advent of earth-orbiting satellites,
very long range communications like between continents was dependent on the state of
the various ionosphere levels. There is never a completely predictable "open" channel
from point A to point B. A satellite repeater, however, while not always in a position
to be within view of both points, at least is predictable based on a published ephemeris
of times and positions. The first
OSCAR (Orbiting Satellite Carrying Amateur Radio), now governed by AMSAT,
was launched in December of 1961. This 1973 article in Popular Electronics
mentions OSCAR 6, which was launched in October 1972...
The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has a Butterworth
Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but
also phase and group delay! Since 2002,
the original Calculator Workbook has been available as a free download.
Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is
also provided at no cost,
compliments of my generous sponsors. The original calculators are included, but
with a vastly expanded and improved user interface. Error-trapped user input cells
help prevent entry of invalid values. An extensive use of Visual Basic for Applications
(VBA) functions now do most of the heavy lifting with calculations, and facilitates
a wide user-selectable choice of units for voltage, frequency, speed, temperature,
power, wavelength, weight, etc. In fact, a full page of units conversion calculators
is included. A particularly handy feature is the ability to specify the the number
of significant digits to display. Drop-down menus are provided for convenience...
Robert Gary waxes philosophical on the subject
of ground in his Electronics World article, "'Grounds' for Confusion." He is justified from the viewpoint of
someone attempting to make sense of how something as seemingly fundamental as Earth
ground is not a constant. The layman probably doesn't care. Practitioners in the
electrical and electronics realms who deal only with low frequencies and short distances
might occasionally be affected by differences in ground potentials, although they
might not realize it is the cause of their problems. Those with more than a casual
involvement (designers, installers, and maintainers as opposed to only users) in
high frequencies and/or long distance signal interconnections are likely to be intimately
familiar with the effects of ground potential differences. RF Cafe visitors are
undoubtedly members of the latter group...
This entire page has been reworked to make
the denormalization
of prototype lowpass filter component values much easier to understand. I have received
numerous questions about the process over the years, particularly regarding the
swapping of capacitor and inductor values for highpass transformations. Bandpass
and bandstop transformations can be equally confusing. The original page pretty
much regurgitated the kind of presentation made by many textbooks, but this new
format should make amply clear the transformation from normalized lowpass component
values ...
Dr. Lee DeForest might have had something
like National Public Radio (est. 1970) in mind when he penned this article in 1933.
In it, the famous vacuum tube amplifier inventor lamented and criticized the commercialization
of broadcasts because of all the paid product announcements (aka commercials) that
had been steadily increasing over the years. He also was critical of the "hit-or-miss,
higgeldy-piggeldy mélange program basis" of programing; i.e., the same station playing
a mix of jazz, opera, swing, syndicated story-telling, etc. The good doctor did
not elaborate on where funding for such dedicated, uncorrupted broadcasts would
originate if not from paying advertisers, and I do not recall ever reading about
a DeForest Radio Network paid for by his vast fortune. I don't like commercials
any more than the next person, but a company deserves time to pitch its products
and/or services if it helps deliver a source of entertainment to you that...
The word prefix "para" can mean "above and
beyond" or "resembling" or "abnormal or incorrect." Ward Products probably preferred
first two be inferred by potential customers when naming their
PARA-CON television antenna, although it actually is a shortening of "parabolic."
The "con" part is a shortening of "conical." After reading the text of this full-page
advertisement from a 1951 issue of Radio & Television News magazine, I'm inclined
to assign the third prefix meaning of "para" to it. Then, add in the "con" part
where "con" can take on either the noun form meaning of "disadvantage" or the verb
form definition of "to trick or defraud," and you get what this antenna truly represented
in terms of achieving superior performance. At best the PARA-CON exhibited the characteristics
of a phased pseudo-[bi]conical antenna. The allusion to a parabolic antenna...
We don't hear much - if any - talk these
days about a certain weapon type being a "peace maker," "game changer," or a "stale
mate proposition." That is because most nations, or for that matter terrorist groups,
have access to some ferocious weapons. The world has operated for a long time on
the Mutually Assured Destruction (MAD) principle, where skirmishes have been fairly
local. Many conspiratorialists as well as arguably rational people believe the real
game at hand is Mutually Assured Financial Destruction (no clever acronym for that
one), where world financial powers cooperatively trade off monetary wins and losses
via what was termed by President Eisenhower the
Military-Industrial Complex. You don't need to be one who wears a tinfoil hat
or keeps your savings buried in a jar in the back yard to suspect at least some
form of malfeasance is going on at the expense of we the little people... |