|
 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.
 Each week, for the
sake of all avid cruciverbalists amongst us, I create a new
technology-themed
crossword puzzle using only words from my custom-created lexicon related to
engineering, science, mathematics, chemistry, physics, astronomy, etc. You will
never find among the words names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort. You might, however, see someone or
something in the exclusion list who or that is directly related to this puzzle's
theme, such as Hedy Lamarr or the Bikini Atoll, respectively. Enjoy!
 Prior to around 1960, the nature of electromagnetic
radiation outside the Earth's atmosphere was entirely a matter of scientific conjecture.
As is evidenced by this 1961 Popular Electronics magazine article, at the
time it was still not known for certain whether electromagnetic energy outside the
bands transmitted through the
ionosphere existed for sure. There was of course no reason to believe that low
frequency, long wavelength radio waves were not present along with the rest of the
spectrum, but experiments needed to be developed that would launch satellites above
the atmosphere to detect probable out-of-band signals and then re-transmit them
on frequencies known to easily penetrate the "ether." Many failures occurred along
the way, but persistence paid off in what is today a very well explored and documented
outer space. Prior to the last half decade, groups like NASA were more interested
in conducting research than wasting precious allocated funds on unrelated projects
like the utterly unrelated studies...
 It was a lot of work, but I finally finished
a version of the "RF &
Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft
Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive
set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog,
antenna, and other commonly used symbols for system block diagrams and schematics
created for Visio™. Each of the 1,000+ symbols was exported individually from Visio
in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format
allows an image to be scaled up or down without becoming pixelated, so all the shapes
can be resized in a document and still look good. The imported symbols can also
be UnGrouped into their original constituent parts for editing...
 Here is an overview of the sort of topics
an applicant for an FCC
Commercial Radio Operator License needed to know - back in the 1940s, anyway.
Much of it still applies to obtaining the same license today. Per the FCC website:
You need a commercial operator license to operate, and/or to repair and maintain,
specified ship, and aircraft radio communication stations. The licensing requirements
for operating such radio stations and the licensing requirements for repairing and
maintaining such radio stations are discussed [herein]." Examples are ships or aircraft
traveling to foreign destinations, ships employing radiotelegraphy (some still do
for emergency communications; e.g., ••• --- •••), and vessels carrying more than
six passengers. A license is required to repair and align radio, radar, and navigation
equipment...
 "Transatlantic
News" was a regular column in the 1940 issues of Radio-Craft magazine,
written by their European correspondent Major Ralph Hallows. As the title suggests,
it reported on happenings from across the pond. A couple items caught my attention
in this edition. One is about one of the first instances of the prediction of existence
of a D-Layer in the ionosphere based on radio signal propagation characteristics
noted by operators. The article estimates a height of about 30 miles, while the
modern definition of the D-Layer places it at between 60 km (37 mi) to 90 km (56
mi). It also has a piece describing a simple method for silver plating without the
need for supplying an electrical current. It involves making a paste of silver chloride
and cream of tartar (potassium bitartrate) and rubbing it on the target metal. Supposedly
the bond is as durable as electroplating...
 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...
 Camouflaging amateur radio antennas and their
mounts is not a new concept, although an increasingly large amount of prohibitions
by community organizations and/or municipalities have made the lives of many hobbyists
more difficult. The ARRL's QST magazine issues are replete with articles
describing how desperate and determined Hams have managed to erect successful antennas
in spite of imposed limitations. Flag poles have long been the means of disguising
vertical antennas of the 1/4-wave, 1/2-wave, J-pole, and other formats that are
constructed in a long, straight line. Some authors are just-the-facts types and
aptly present all the required information for getting the job done. Others, like
Roland McMahan, throw in a bit of humor to help take the bite out having such an
otherwise unnecessary task imposed upon him - in this case at the "request" (pronounced
"insistence") of his YL...
 Dealing with on-site traveling salesmen has
always been a sort of love-hate (or maybe a necessary evil, to put it less extremely)
relationship - for both the salesman and the engineer/technician. Not having been
in the engineering design environment for nearly two decades, I don't know how much
face-to-face contact is made anymore. Up through the early 2000s, I was still occasionally
meeting with components salesmen. In this June 1952 issue of Radio & Television
News magazine's
Mac's Radio Service Shop technodrama, proprietor Mac McGregor takes the occasion
of an afternoon rain torrent to discuss the situation with two of his regular sales
representatives. The open trading of pet peeves and appreciated behavior on both
sides is common sense stuff, but are courtesies often forgotten while in the throes
of the daily work grind. Mac references a book...
 Here in this 1954 issue of Radio &
Television News magazine is one man's (Commander Paul G. Watson, USNR (ret.)
collection of early vacuum tubes and a bit about them. It reaches back to Dr. Lee
de Forest's farther than even earliest Audion tubes - including the "UltraAudion"
- to include the flame-based detector and amplifiers he worked on. For a very thorough
history of de Forest's work from the vantage point of both the good Dr. and
those who worked with him, including a story by William Howard McCandless (the man
who's glass blowing business built the various tubes for de Forest), check out
the January 1947 issue of Radio-Craft magazine. It celebrated the 40th
anniversary of the de Forest Audio tube. I wonder where this collection of
tubes is today. Many priceless collections of technical history artifacts end up
being mistakenly or ignorantly disposed of...
 Bell Labs, having been responsible for creating
the first positive amplification point contact transistor just before Christmas
1947, continued to lead the way in semiconductor research and new product announcements
for many decades. This little tidbit was tucked away at the bottom of page 120 in
the May 1954 issue of Radio & Television News magazine. It reported on "the
purest substances in the world" being created there in the form of 99.99999999%
(aka 10N)
pure germanium crystals, which are used as seed for growing boules for device
production. That's one rogue impurity atom in ten billion germanium atoms. Modern
monocrystalline silicon boules are typically 7N or better...
 Little could Electronics World magazine
editor William Stocklin have known in 1965 when he wrote this "The
Battery Renaissance" article the advances in technology that would occur half
a century later. Consumer products were at the time just becoming small, energy
efficient, and inexpensive enough for widespread adoption, having only recently
evolved from high voltage and power vacuum tube circuits to transistorized versions
of radios, televisions, tape recorders, and other portable devices. Carbon-zinc
batteries still dominated the markets and came in relatively high voltage packages
to power voltage multiplier circuits for tube biases, but alkaline and mercury batteries
did the job for transistors where non-rechargeable cells were used, and nickel-cadmium
(NiCad) was the rechargeable battery of choice. Those chemistries ruled for decades,
until nickel-metal-hydride (NiMH) came on the scene in the 1990's with a higher
energy density than NiCad, and then the advent of Lithium-Polymer (LiPo) trumped
them all. Of course at the same time semiconductor devices were shrinking in size,
power consumption, voltage requirements, and cost. It is hard to imagine where the
market goes from here. I won't be here fifty years...
 Here is a really interesting animation of
the world's top 20 country ranked by the
number
of Internet users in those countries. It runs (as of this posting date) from
1990 through 2019. I have not verified the numbers used by the Animate Stats producers,
but the results do not seem unreasonable. Given the the U.S. Department of Defense's
research arm, Defense Advanced Research Projects Agency (DARPA), created the Advanced
Research Projects Agency Network (ARPANET) that eventually became the Internet,
showing the U.S. as the run-away leader in the beginning is not surprising. Around
1996, things begin to change quickly as Japan advances, but it is in 2000 when the
Internet user landscape really becomes dynamic...
 Even with the ready availability of
programmable calculators and smartphone apps, there are still times when having
a handy-dandy
nomograph printed out and hanging on the wall for quick reference can be a
great asset. This nomograph which appeared in a 1965 issue of Electronics
World magazine provided ready conversion between two different (input and
output) voltage and power values to equivalent decibel values. It seems strange
that the watts and voltage scale is on the left and the milliwatts and
millivolts scale is on the right. That might be more intuitive for a nomograph
of attenuation, but not - at least to me - for positive gain as through an
amplifier...
 Have you ever wondered what is inside the
familiar 9-volt battery (often referred to as a "transistor
radio battery" in the last century)? I have read about there being AAAA cells
(that's right, quadruple-A, A-A-A-A), but wanted to see for myself. So, I used a
small screwdriver and a pair of pliers to remove the outer metal case. This first
picture shows the six AAAA cells bundled together and contained with heat-shrink
tubing. In the bottom photo, you can see that all six AAAA cells are connected in
series. Each individual cell is 1.5 volts, so 6 x 1.5 = 9.0 volts.
For a size comparison, a standard triple-A (AAA) cell is shown next to one of the
AAAA cells. Here are the specifications for the Duracell Ultra 9V battery: Battery
Capacity: 550 mAh Battery Technology: Alkaline (Single Use) Current: 2.1000 A Depth:
17.0 mm Height: 48.5 mm Width: 26.2mm Voltage: 9.00 V Weight: 44.0 g Since the cells
are connected in series, than means the overall current rating for the battery assembly
is the same for each AAAA cell. So, each AAAA cell is rated at 2.1 amps with an
energy capacity of 550 mAh (milliamp-hours)...
 After having read many articles about Dr. Lee
de Forest, it seems the poor guy was besieged his entire life by envious and/or
belligerent electronic communications compatriots who sought to defame him and/or
deny him of monetary rewards. This January 1947 issue of Radio-Craft magazine
includes a dozen or so pieces written by friends and colleagues who recognized the
momentous struggles and achievements of Dr. de Forest. Such burdens of
fame are borne by many - if not all - persons of similar celebrity. Dogged persistence
is the order of the day for experimenters and breakers-through of assumedly impenetrable
walls. Guys like de Forest lived by the old adage recommending that "if at
first you don't succeed, try, try again." You'll be amazed at how de Forest whipped
- almost literally - that thing which was preventing his
wireless telephone from working. BTW, as I've pointed out before, you will find
the good doctor's last name written as "de Forest, DeForest, and De Forest."
As evidenced by his signature...
 The probability-based
quantum mechanical model of atoms has been in existence since around 1932 when
Robert Mulliken coined the term "electron orbital." It superseded the Bohr model
that modeled the atom as a proton/neutron nucleus that was surrounded by electrons
orbiting like planets around a star. For many decades thereafter, text books - particularly
those used in beginner level courses - continued to present the Bohr model and only
gave passing reference, if at all, to the quantum model. The Bohr model was and
still is easier for most people to envision, although as time goes on the percentage
of people who even recognize a planetary model is probably rapidly decreasing. This
article from a 1944 edition of Radio-Craft magazine chooses to use the Bohr model
as part of an introduction to electronics. Today, you might need to start from a
lower point and talk about groupies swarming around rock stars for most people...
 Mac McGregor, owner of
Mac's Radio Service Shop, can always be counted on to provide
his apprentice technician, Barney, with a lesson from his own life-long attendance
at the School of Hard Knocks. Barney is your stereotypical young buck whose level
of seriousness needs occasional alignment, just as do the radio and television sets
he services. In this episode, I can't find where Mac actually solved the intermittent
electrical condition believed to be causing the problem - weird. The "Mac's Radio
Service Shop" series ran in Radio & Television News magazine for many
years prior to a similar electronics story series called "Carl & Jerry" that
appeared in Popular Electronics. Both were created by consummate storyteller
John T. Frye.
 Here's one last thing to do before you
leave work for the weekend. This "Polarity
Quiz" by Robert Balin appeared in a 1968 issue of Popular Electronics.
If you know your left- and right-hand rules for magnetism and induction, then a
100% score is practically guaranteed... provided you also are a whiz at diode and
meter connections. Since the author did not do so, I provided brief explanations
for the answers at the bottom of the page. When applying the hand-rules, assume
conventional current (flow from more positive to more negative), not electron current. |
