|
 If
Radio Corporation of America (RCA) was still in existence today, undoubtedly
it would be running an advertisement mentioning not just radio and television in
their list of wireless communications accomplishments, but also cellphones, satellite
navigation (GPS), cable television, and Wi-Fi. Founded in 1919, RCA was bought by
General Electric in 1986 and then subsequently broken into components and sold off
to other companies like Sony, NBC (National Broadcasting Company), and Comcast.
This RCA advertisement heralding Marconi's Morse code message "first forged
in 1901 from the mere sound of three dots" appeared in a 1952 issue of Radio &
Television News magazine...
 "Researchers have created an
ultra-compact nanolaser
that could transform how data moves within microchips, replacing electrical signals
with light. The idea of computers communicating with light instead of electricity
is moving closer to reality, thanks to a breakthrough nanolaser developed at the
Technical University of Denmark (DTU). Described in Science Advances, the device
is small enough to be embedded by the thousands onto a single microchip. Instead
of relying on electrical currents, which generate heat..."
 It seems that creating almost cartoonish-looking
antenna arrays for the purpose of signal gain and directivity are usually relegated
to the domains of military and amateur radio practitioners, but this article from
a 1952 edition of Radio & Television News magazine was done by the
Channel Master Laboratories television antenna company. Successfully
mounting and phasing even two antennas can be challenging, but in this case
four Yagis were arrayed and tuned for operation. Trying to make
the system work over the entire 4 octave band that is the VHF broadcast realm (54
MHz for channel 2 to 210 MHz for channel 13) would be nearly impossible without
extremely...
 First prize in this circa 1936
reader-submitted design ideas went to William G. Scott for his
wind-powered battery recharger. It was a rather elaborate contraption made of surplus
lawn mower and automobile (Ford Model T, no less) generator. There are two very
good reasons why someone would find the need to build his own battery charger in
the era. First, good luck finding a commercial product to do the job, and if you
could, the cost would be prohibitive for most radio enthusiasts. Second, prior to
the Rural Electrification Act of 1936, most households not in or near cities and
towns had no commercial electric service. Electricity, if any, was...
 Technodrama stories were a popular means
of teaching valuable lessons back in the mid-twentieth century. Carl and Jerry,
Mac's Radio Service Shop, Sally the Service Maid - even Hobnobbing with Harbaugh
- et al, were very popular features. Popular Science magazine's Gus Wilson's
Model Garage was a gearhead equivalent. An occasional non-regular feature appeared,
as with this "Pedro
and the Swami" troubleshooting adventure in a 1959 issue of Radio-Electronics
magazine. You will like the ending. As a long-time troubleshooter of electrical,
mechanical, and hydraulic systems, I always read these kinds of things. Pull up
a chair and take a read through it; you will appreciate the combination of reductio
ad simplicitatem, reductio ad absurdum...
 These two
electronics-themed comics appeared in circa 1952-53 Radio &
Television News magazine. For some reason the early 50s were a little comic
challenged. I really like the one with the guy hanging from the antenna! It's hard
to make out the artists' names, but they have appeared on other comics of the era.
If you enjoy comics like this, there is a growing list of other comics at the bottom
of the page you can check out. I took the liberty of colorizing them...
 "Engineers aren't bad at communication.
They're just speaking to the wrong audience. There's a persistent myth that
engineers are bad
communicators. In my experience, that's not true. Engineers are often excellent
communicators - inside their domain. We're precise. We're logical. We structure
arguments clearly. We define terms. We reason from constraints. The breakdown happens
when the audience changes. We're used to speaking in highly technical language,
surrounded by people who share our vocabulary. In that environment, shorthand and
jargon are efficient..."
  RF Cafe visitor Mike H. sent me these
two photos of the same type Silvertone radio as I discovered in Tony Packo's. He
says there is no part number marked anywhere, so its identity was still a mystery.
Well, no more! I decided to use my paid subscription to newspapers.com to search
for an advertisement from an old newspaper. Sure enough, there was a full-page advertisement
by Sears, Roebuck, and Co., in the October 23, 1936 edition of the Rio Grande
Farmer that appears to include this model. Until proven otherwise, I hereby
declare the
Tony Packo's radio to be the "7 Tube Silvertone Battery Console."
Battery powered radios were quite common in 1937 because commercial AC power distribution
lines did not extend to many rural locations, and many urban homes...
 Maybe it isn't so anymore, but according
to Centralab the ceramic raw materials available in abundance in America were electrically
superior to those being used in Europe since the early 1900s when German scientists
first discovered the dielectric properties of the material.
Ceramic capacitors represented a major advance in capacitor technology
over liquid and paste dielectric types in most areas of electrical and mechanical
specifications such as vibration, aging, vibration and shock, temperature, value
stability, voltage and current handling, etc. Centralab ran this advertisement spelling
out all the virtues of ceramic capacitors...
 Radio-Electronics magazine ran a monthly
"News Briefs" section that corralled happenings in the industry. Included were inventions,
product announcements, events, demonstrations, job promotions, company headlines,
and even death notices. Notably in this 1959 installment was the announcement of
the passing of one of the
Varian brothers, Russell. He and his brother, Sigurd, are credited with inventing
the klystron microwave tube. Also highlighted was the short-lived phenomenon called
the Ovitron. It was a current-amplifying device that consisted of two plates immersed
in an electrolyte, with a control grid modulating the current - essentially a liquid
tube as opposed to a vacuum tube. The Ovitron suffered...
 Assuming the 10 enumerated advantages of
a gridless vacuum tube may be added to the 17 enumerated disadvantages of a gridded
vacuum tube, there are 27 reasons, per author Henri Dalpayrat why one should consider
abandoning the "old style" tubes for his revolutionary concept.
Part 1 of this 2-part series discussed the unavoidably negative
features of a gridded vacuum tube. Part 2, presently, extolls the wonders of a gridless
tube. Chief among the features is the use of "compressor bar" elements that are
situated parallel to the electron flow rather than in series with it. Another major
difference is the cathode element...
 "SpaceX has filed confidential paperwork
today for its initial public offering (IPO), according to Bloomberg and the New
York Times. The company plans its IPO for June and founder Elon Musk aims to raise
$50 billion to $75 billion, which would make it the
largest IPO Wall Street has ever seen. SpaceX currently values itself at more
than $1 trillion, according to the NTimes. The company is an umbrella that includes
not only the SpaceX rocket company but also xAI, Starlink, Grok and X. A confidential
filing means that the financials of the company are not disclosed until later..."
 The ability to generate clean, controlled
radio waves at 3 THz in 1937 was about as attainable as putting a man on the
moon. That did not stop scientists and engineers from theorizing how to get there
and what to do once attained. That's the way science progress happens. An official
name had not yet been given to the spectrum realm, but news reporters conjured up
the moniker "mystery rays." Even scientists called it the "black gap." Both sound
a bit hokey and there is a temptation to poke fun at the renown technical ignorance
of most media types, but no less a science giant as Albert Einstein referred to
quantum entanglement as "spooky action at a distance." The big idea of author W.E.
Shrage was to exploit and extend the concept of a cathode ray tube (CRT) to convert...
 CPC Amps recently released its latest product
to complement their full line of solid state high power RF and microwave amps. Pulsed
RF system requirements are now easily met with CPC Amps' S-band solid state power
amplifier (SSPA). Operating from 2700 to 3500 MHz, the
AM-2700-3500-2E2 will deliver up to 250 W of power with 48 dB of nominal
power gain for pulsed applications including radars, radar test equipment, and EW
systems. Pulse widths of 200 µs with duty cycles of 20% are easily supported.
Built in a rugged, low-profile connectorized housing, the unit delivers superior
performance in a small form factor...
 You know you've gotten old when you have
an "I remember when..." line for just about every kind of product or process mentioned
in a magazine article, video, or conversation. Here is mine for microwave ovens.
I remember that it was sometime around 1977-79 that my father gave my mother a
microwave oven for Christmas. It was the most expensive gift anyone in our household
had ever received. According to this 1971 Radio-Electronics magazine article,
household microwaves had only been on the scene for about a decade. A look at the
wiring diagram shown for this International Crystal microwave...
 Reading through this article reminds me
of studying for the amateur radio exams. In fact, the information presented in this
1940 QST magazine piece does not seem to be lacking anything that contemporary
discussions include. My point is that a great amount of knowledge had already been
amassed about earth's
upper atmosphere a mere four decades after the first transatlantic
radio communications were accomplished by Marconi on December 12, 1901 from Poldhu
in Cornwall, England, to Newfoundland, Canada. Considering that at the time no instrumented
sounding rockets had been launched into the extreme upper layers (F1 & F2, beginning
at around 120 mi | 200 km), a lot had been discerned about characteristics as they
pertain to radio communications. Balloons were...
 "We've seen the writing on the wall for
awhile that data centers need fiber and lots of it. Research from RVA LLC has now
done the math and worked out that providers need to build about
92,000 new route miles in the next five years to support that demand. Suffice
to say, the pressure is on for suppliers. 'Everybody talks about the constraints
of power, cooling, land and chips and so forth, but fiber is also a constraint,'
said RVA Founder and CEO Mike Render at a Fiber Broadband Association (FBA) webinar
Wednesday. He noted a single cable can contain 'hundreds or thousands' of fiber
strands and that cabling will only get smaller..."
 These three
electronics-themed comics appeared in the November 1948 issue
of Radio & Television News magazine. You don't need to be of the era
in order to appreciate the humor, but Millennials might need a little assistance
with the second one. That contraption sitting the desk is called a "turntable,"
and it used to play audio media called "records" by spinning them at a certain rate
(33-1/3 rpm, 45 rpm, 78 rpm), while that horizontal lever called
a 'tone arm' held a piezoelectric needle in the grooved tracks of the record. The
joke here is the guy having to spin his head while trying to read the printed label.
I'm just joshing the Millennials, of course, since they use spinning disks called
CDs and DVDs for listening...
 These are
close-up photos of common household objects. Your mission, should you decide
to accept it, is to identify each one. Most are fairly easy, but a couple are a
little outdated since they appeared in a 1939 edition of Boys' Life magazine.
Answers are way down at the bottom of the page. BTW, this January issue is the one
Ralphie Parker is reading in the movie A Christmas Story...
Exodus AMP20110,
0.5-6 GHz, 150 W SSPA
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Exodus'
AMP20110 is a rugged, ultra-broadband solid state power amplifier (SSPA) designed
for all applications. Frequency range of 500 MHz-6.0 GHz (P-, L-, S-band),
150 W minimum, and 53 dB gain. Excellent power/gain flatness as compared
to other amplifiers. Forward/Reflected power monitoring, VSWR, voltage / current
/ temperature sensing...
 This 1971 Radio-Electronics magazine
article provides a comprehensive technical overview of
laser theory and practical application. It explains that laser action requires
a population inversion within a medium, typically contained in an optical cavity
with reflective surfaces to amplify coherent light through stimulated emission.
The author distinguishes between three-level systems, such as the ruby laser, and
four-level systems, exemplified by the helium-neon gas laser. Advanced techniques
like Q-switching are described as methods to achieve high-power pulses by interrupting
the cavity. Beyond core physics, the text explores the diverse utility of lasers
in engineering and biology...
 Next Spring I will be installing an old-fashioned
(but newly manufactured)
Channel Master television antenna on a short tower with a rotator.
Here in Erie, Pennsylvania, under certain conditions I can receive broadcasts from
Erie and many of the cities that border close to Lake Erie like Toronto and Waterloo,
Canada and even Detroit. AM radio stations are easily pulled in from the same areas,
but FM does not do quite so well. I plan to also integrate some form of FM antenna
on the installation. There is something insulting about paying for cable or satellite
TV and then having to suffer the deluge of commercials as well (I have neither).
Nobody likes sitting through commercials, but at least if the programming is being
delivered at no cost, it is not unreasonable for the broadcast...
 "Just when you thought it was safe to go
back into the networking waters, the Federal Communications Commission (FCC) throws
a curveball. This one is directed squarely at the consumer-grade router industry.
The FCC on Monday announced that all
consumer-grade routers produced in foreign countries are banned from sale in
the United States – unless the supplier applies for and receives a 'Conditional
Approval' from the Department of War (DoW) or the Department of Homeland Security
(DHS). Existing Wi-Fi routers and those that were previously approved by the FCC
can continue to be operated and sold..."
 Before most people listened to radio and
television programming via cable, satellite, and/or the Internet, broadcasts were
received over the air, usually from local stations. A common problem in the days
of vacuum tube Ham transmitters back in the day was inadvertently causing
broadcast interference (BCI) or specifically in the case of television, TVI,
due to insufficient filtering, shielding, or design. Nowadays, we generally refer
to all such unintentional and incidental radiation as radio frequency interference
(RFI). Lots of articles were written on the subject in the 1940s through about the
1970s. Some RF spectrum is shared by more than one entity per FCC and other countries'
band plans, with primary and secondary allocations assigned...
 I have always been a stickler for creating
neat, orderly arrangements when building any type of circuit assembly. Many moons
ago when starting out as an electrician, I made a point of installing straight runs
of Romex type cable with no twists, evenly spaced staples, and keeping the identification
marking to the outside. Conduit was precisely bent and installed, again with organized
parallel runs and even spacing where possible. Circuit breaker panel wiring looked
like something seen in an Apollo space capsule. Electrical inspectors often complimented
my work. Moving on to an electronics career, the habits carried over when prototyping
and even when directing layout for production PCBs or chassis assemblies, including
cabling. The greatest enjoyment I had was when laying out runs of
waveguide...
|
 • Shielding
Electronics Supply Chain from Cyberthreats
• FCC
Warns Ham on Out-of-Band Transmissions
• On-Chip
Temperature Monitoring
• UK, US, Others Set
6G Security Principles
• AI
Boom Drives Memory Shortage
 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.
 In 1942 and throughout the War Years,
Life magazine (and many others) ran many articles promoting industries,
services, organizations, and individuals who contributed toward our ultimate victory.
Of course no one knew for certain that we would prevail in the end, but if it hadn't
turned out that way, it wouldn't have been for lack of effort and sacrifice. Part
of the objective was to inform the populace about how the country was pooling its
resources - physical, labor, and mental - to defeat the Axis Powers that sought
to takeover the world. This particular issue of Life focused on the
chemical industry, with the raw materials and processes used to produce needed
products both for fuel and for the base components of other finished goods. Sulphur,
potassium, and coal mining and processing, along with petroleum, common table salt,
and air and water were some of the most fundamental ingredients of every other item
needed to aid the effort. Ever hear of Ameriopl rubber?
 Edward Weston was a pioneer in the
photoelectric cell field. His "photronic" cell was one of the first successful
devices for commercial use. Just like with early battery cells, photoelectric cells
of the era required a liquid medium to facilitate electron transfer and thereby
generate electric current. The lead nitrate compound used by Weston is now considered
a possible human carcinogen. Mr. Brooke Clark has a web page with extensive data
on the history of Weston's photoelectric sensors, meters, test data, patents, and
history of his company - which now has the name Huygen Corporation. Photoelectric
science has advanced significantly in the 80 years since this article was published.
A good website to visit regularly if you like following progress on photocell technology
is Semiconductor Today...
 Thanks to Chuck U. for providing new
Watkins-Johnson (WJ) Tech Notes v10-3 and v15-2, and an
improved copy of v5-2. A lot (but not all) of the TNs that I had or other people
sent to me are made from B&W copies from old scanners, so the quality is not
super good. Chuck's versions appear to be scanned from the originals in color,
so they're very good...
 QST reader George P. Orphan, KG4DXJ,
wrote in the February 2020 issue's "Letters from Our Members" column about an episode
of the old "Hazel" television show entitled, "Stop Rockin'
Our Reception," where interference on the Baxters' TV set was blamed on the
"shortwave set" operated by a teenager, Bruce, who had recently moved in down the
street. George Baxter, the household's impulsive lawyer father, was convinced enough
that Bruce, a friend of his son, Harold, was responsible that he paid a visit to
the boy's house and spoke to his father about it. Bruce politely informs Mr. B
that unless his television was was manufactured before 1950, it was unlikely that
his operations on the 10-meter band would be causing the interference, but it fell
on deaf ears. Shortly thereafter, a power company investigator was seen walking
around the front yard with a box bearing a loop antenna on the top of it. At the
request of Bruce's father...
 Every once in a while an RF Cafe visitor
writes to let me know that he or she found one of the vintage electronics magazine
articles I post regularly useful. It helps to validate my efforts, which is critical
for motivation to continue. A couple days ago Mr. Dave Jones (N1UAV), sent
me a note about the stacked television antenna project he undertook after finding
the "How
to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts" article
from the November 1965 issue of Popular Electronics magazine. His location
about 90 miles outside of Nashville, TN, is a challenge for trying to receive a
good signal from a television station from both an attenuation and multipath signal
degradation perspective. Dave began with a single antenna, but was not happy with
the performance. The results of adding the second antenna is amazing...
 In the 1930s, electricity and electronics
were mysteries to most of the population. The concepts were relatively new and few
had a firm grasp on the technology. That reality was exploited by Hugo Gernsback
during the
1934 Electrical Exposition to challenge attendees to discover how the radio
receiver sitting on the top of an empty, clear glass case was being powered. It
was a clever ruse that reportedly stumped most people. The secret is revealed here
in this 1934 issue of his Radio-Craft magazine. BTW, my guess is that an
even smaller proportion of our current citizens would be able to figure it out,
or for that matter even realize that maybe there should be a power source of some
sort...
 The early 1960s was evidently a good time
for printing quizzes in electronics magazines. Popular Electronics was
no exception. As I look through my collection I am finding quite a few. Here is
the latest, from the January 1963 edition, that tests basic knowledge of
using analog multimeters (digital types were not around yet). All are
pretty straightforward; however, be careful with question 9. At first I thought
maybe it was a trick question, but the key to arriving at the correct answer is
noting that you are measuring a low resistance. Be sure to consider the
properties of a standard multimeter of the era. Give it a try for yourself to
see how well you fare...
 This advertisement for transformers, coils,
chokes, and rotary converters from
William Bayliss Ltd., on Sheepcoat Street in Birmingham, England, appeared in
the March 9, 1932 edition of The Wireless World magazine. I only have this one edition,
but will work on getting more soon. William Bayliss London Ltd. was a British manufacturer
of scientific instruments, founded in London in 1919 by Sir William Maddock Bayliss,
a well-known physiologist and Fellow of the Royal Society. The company specialized
in the production of laboratory equipment, including microscopes, balances, and
other precision instruments used in scientific research and education. One of the
company's most significant contributions to science was the development of the Bayliss-Tate
apparatus, a device used to measure the concentration of oxygen in blood. This instrument
was based on the discovery made by Bayliss and his colleague, Ernest Starling, that
the oxygen-carrying protein hemoglobin in blood changes color depending on the amount
of oxygen it is carrying. The Bayliss-Tate apparatus was widely used in medical
research and diagnosis for many years...
 Declaring any kind of straight LC tank circuit
to be high stability is a bit of a stretch when compared the Q available simply
by adding a crystal, even in 1958. Tone modulation was an early method for achieving
remote control of model airplanes, boats, and cars. The number of channels with
these
tone modulation systems is two times the number of modern proportional
systems in that moving the rudder left took one channel and moving it right took
another. Up and down elevator likewise took two channels. Therefore, this four
channel system is only two channels by today's terminology. Technology evolved
into fully proportional ...
 Here is another one of those ads you would
not likely see in a present day engineering magazine. Today, you'll routinely find
racier images in JC Penny and Target advertisements (although in the latter example
the girl might not be a real girl). Loral Electronics is a well-known defense systems
contractor founded in the late 1940s by William Lorenz
and Leon Alpert. Loral specialized in aerospace and avionics
(airborne) systems like radar, radios, satellite navigation and communications.
They also had a component distribution division which sold, among other items, the
Arcolytic capacitors represented in this 1968 Radio-Electronics magazine
promotion. Lockheed Martin bought Loral in 1996, the same year Loral was accused
of transferring missile stabilization technology to China, which was useful in their
Long March intercontinental ballistic missile (ICBM) program.
 If you like pictures of très cool-looking
devices involving vacuum-filled (an oxymoron?) glass enclosures, i.e., lamps and
tubes, then you will want to spend a few minutes perusing the personal collection
of Giorgio Basile, of Nivelles, Belgium. Per the homepage of his
Lamps & Tubes website:
"My collection consists of more than 4,000 lamps and vacuum tubes. This is a wide
area! In addition to well known incandescent lamps, radio tubes and cathode ray
tubes, it includes, among others: arc lamps, light sources for the laboratory, transmitting
tubes, camera tubes, flash lamps, microwave tubes, photocells, photomultipliers,
radiation detectors, rectifiers, relays, thyratrons, vacuum gauges, X-ray tubes...
 Use of a
load line chart is a fast way of selecting the bias (operating) point and operational
range for nonlinear devices. Notice that I didn't specifically say for transistors
because this particular article deals with load lines for vacuum tubes. Almost nobody
has any need for tube load line charts anymore, but the skill needed to interpret
load lines for transistors is fundamentally the same as for tubes. Substitute Vce
(collector-to-emitter voltage) for Plate Volts and Ic (collector current) for Plate
Milliamperes and you have equivalence. Popular Electronics magazine ran
this "After Class" tutorial series covering a broad variety of topics for many years.
There is a short quiz at the end...
 The history of electrical current is replete
with tragic incidences of maiming and death caused by ignorance and/or inattention
to known danger. Having been involved in both the electrical wiring and the electronics
fields since the 1970s, I am quite aware of the legion of hazards present when current
flows. My tool box contains screwdrivers and lineman's pliers with notches of melted
metal from inadvertent contact between differences of potential in circuit breaker
panels and electrical wall boxes. Once you experience the thrill of a sudden blinding
flash, unique buzzing sound, and smell of burning hot steel, you'll never forget
it. Those incidences could have been avoided with more careful work practices. A
lot of people have been
electrocuted, though, through no fault of their own, if ignorance (as opposed
to stupidity) is a valid excuse. Early radios, televisions, and other household
appliances did not have a safety ground...
 Just as with the poor, the spies will always
be among us. This story reports on a bookstore in New York that during World War II
funneled money and technical information back to the Nazi Party in Germany. Electronics,
aerospace, and other technical publications (including Radio-Craft magazine)
were chief among the sought-after sources. The shop was a front operation which
lost a huge sum of money per the official accounting books, but had copious amounts
of funds pouring in from German "investors." Today's enemy money fronting operations
are largely radical religious and communist entities collecting funds from America-hating
groups and individuals who live and thrive here. Did you know it was during WWII
that Persia began being commonly referred to as "Iran," which has the same etymology
as the Aryan (the similarity in sound is no coincidence) movement that accompanied
Nazism? Both groups aspire(d) to eradicate the Jewish people from the face of the
Earth. The more things change, the more things stay the same...
 "Eventually," Dr. Herwald said, "we believe it
will even be possible to automatically and continuously produce actual electronic equipment,
such as radio receivers and amplifiers, starting from a pool of molten semiconductor
materials." That was in early 1960 in an Electronics World article titled, "Molecular
Electronics." The term "molecular" references what eventually became integrated circuits
(IC), the first of which was realized in 1958 by Texas Instruments engineer Jack Kilby.
Kilby's IC incorporated one transistor, one capacitor, and three resistors on a germanium
substrate. Building on that success, researchers envisioned single-chip semiconductors
which contained hundreds, thousands, and even millions of transistors, diodes...
 This week's
wireless engineering-themed crossword puzzle, as is the case every
week, contains only words pertaining to science, engineering, amateur radio, physics,
mechanics, mathematics, etc. Making a special appearance is the name of the most
recent company to support RF Cafe through advertising. You will see their banner
graphical ad appearing in the right page border sometime this week ...
 If you have ever placed a
fixed resistor in parallel with a potentiometer to reduce the total resistance,
then you are familiar with how you also convert a linear relationship of the wiper
movement with resistance to one that is nonlinear. That is because the equation
changes from Rtotal = Rx:potentiometer (where x is the potentiometer
position) to Rtotal = (Rx:potentiometer * Rparallel) / (Rx:potentiometer +
Rparallel). The graph of it looks like one of the curves in this chart.
Since the total parallel resistance is always smaller than the lowest value of the
two resistances, the greater the ratio of the two is, the more dominant the smaller
resistance value becomes. That means as the potentiometer wiper approaches the minimum
resistance end of its travel, the parallel resistor attached across it has virtually
no effect. Since parallel-connected inductors and series-connected capacitors scale
in the same manner as parallel-connected resistors, this chart is useful for those
circuits as well. Series-connected resistors and inductors, and parallel-connected
capacitors are simply the sums of their individual values...
 During and immediately following World War II,
the "Monitoring Service" of the
British Broadcasting Corporation (BBC) relentlessly listened to radio broadcasts
from all over the world in order to be able to break headline news and, if appropriate,
pass strategic military information on to Allied command centers (who were simultaneously
doing their own monitoring). This 1946 Radio News magazine article tells of some
of the more significant messages intercepted and how the facility was a highly guarded
secret in order to prevent sabotage and infiltration. At the height of activity,
32 languages were being transcribed into English daily, consisting of more than
300,000 words. Voice, teletype, and Morse code were processed... |
