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 The 20th Century American electronics industry
produced some of the most influential companies in technological history, from the
laboratories that invented the transistor to the factories that put televisions
in every American home. Yet by the end of the century, many of these
iconic names had passed into foreign ownership through a series of acquisitions
driven by globalization, shifting competitive dynamics, and changing corporate strategies.
Finnish, South Korean, French, Dutch, German, Chinese, Japanese, and other international
buyers acquired what had once been pillars of American innovation. Bell Laboratories,
RCA, Zenith, Magnavox, Sylvania, IBM's PC division...
 Sangamo Electric Company was a "heap" big
name in capacitors in the realm in the middle of the last century. The company always
featured an American Indian in its electronics magazine advertisements, and usually
also included some form of "indian-ese" statements as part of the sales pitch. Of
course such marketing schemes would be vehemently raided and those responsible figuratively
"scalped," if you will pardon the gratuitous expressions. As with using names like
the Washington Redskins, the Atlanta Braves, the Chicago Blackhawks, and the Cleveland
Indians to appropriate and celebrate the bravery and might of the named peoples,
Sangamo implied quality, durability, and reliability...
 Phased
vertical stacks of two or more antennas were fairly common in
the television realm - especially once color broadcasts became more dominant in
the 1950s. Up to 3 dB per additional antenna is possible, but due to various
non-ideal physical parameters (summed phase angle, imperfect antenna geometry, etc.),
realized gain is typically in the 2.5 to 2.8 dB range. Higher signal to noise
ratios were needed to guarantee good color separation with the National Television
System Committee (NTSC) and stereo channel audio separation with the advent of Multichannel
Television Sound (MTS). As you might expect, companies appeared claiming to have
invented physics-defying antennas...
 We take a lot for granted these days with
the seemingly unlimited availability of cheap stuff of all kinds - some of it complete
junk and other of it pretty darn good. That goes for electronics components and
complete products and test equipment, tools, automobiles, appliances, and utensils,
clothing, medical equipment - you name it. Something as simple as a
pistol-type soldering gun can be purchased at just about any hardware
or home store, and at a price that when adjusted back to equivalent money in the
1940s would be amazingly cheap even then. For instance a Weller Soldering Gun kit
from Lowes sells for $39.48 today (less when on sale), which would have been $3.44
in 1947
 In its continuing effort to provide RF engineers
the tools needed to perform their jobs, everything RF website has just added an online
S-Parameters
Viewer. Upload your Touchstone files (.s1p, .s2p, .s3p or .s4p) - or a .zip
containing many of them - to instantly visualize S-parameters on an interactive
Smith chart alongside magnitude, phase,
 VSWR and return/insertion loss plots. Compare
multiple parts, temperatures, or production lots side by side, right in your browser.
No software to install and no account required. To the right is an example of a
.s3p diplexer filter file set uploaded as a .zip file.
 Spurious frequency intermodulation products,
often called mixer spurs, are unwanted output frequencies generated by the nonlinear
action of a frequency mixer. In a diode mixer, the same nonlinear diode behavior
that makes frequency conversion possible also generates many additional frequencies
besides the desired conversion product. Mixer spurs matter because they can fall
inside the desired IF, RF output, receiver passband, adjacent channel, image band,
ADC Nyquist zone, or regulatory measurement bandwidth. The practical industry method
for estimating mixer spurs is to use a manufacturer-supplied m x n spur
suppression table which list the suppression, in dBc, of each mRF ± nLO...
 Syzygy is a great word for a Scrabble game.
If you use it on a Triple Word Score (TWS) space where the "Z" sits on a Double
Letter Score (DLS) space, it will net you 105 points. About the only way to do better
is to use all 7 letters on a TWS play, where you earn 50 bonus points added to your
word score (I've done it twice in the last year).
Syzygy is an astronomical term referring to an alignment of three
or more celestial bodies - not necessarily in exact alignment, but within a few
degrees. Astrologers (not to be confused with astronomers) have since their knuckles
no longer dragged on the ground exploited such scenarios to predict various events
both good and bad. That was even before they...
 As with my hundreds of previous
engineering and science-themed crossword puzzles, this one for
May 3, 2020, contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly
two decades. Many new words and company names have been added that had not even
been created when I started in the year 2002. 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...
 Hugo Gernsback is not necessarily a household
name in 2020, but in the early to middle 20th century, he was fairly well known
in both the hard science and science fiction realms. He was a prolific author of
books and magazines in both areas, applying his profound knowledge of technology
and his ability to foretell the futures of many aspects of communications, mechanics,
electronics, and marketing and societal behavior to the aforementioned. This particular
work of prognostication appeared in a 1947 issue of his Radio-Craft magazine.
It presciently claimed that a post-war boom in consumer buying would feed a significant
adoption of FM radio over...
 Exodus Advanced Communications presents
the
AMP20130 high power solid state amplifier , covering the 80 to 1000 MHz
frequency band with 1300 W of power. Our AMP20130 is a rack-mountable High-Power
Solid-State amplifier delivering >1300 W with 61 dB gain across the
80-1000 MHz range with excellent P1dB power. It features Class A/AB linear
design, ultra-wide instantaneous bandwidth, built-in protection circuits, extensive
monitoring, large local LCD display, and remote interfaces. Ideal for EMI/RFI, lab,
CW/Pulse, and communication applications requiring high efficiency...
 As long-time RF Cafe visitors are aware,
my series of RF Cascade Workbook™ spreadsheets, based in Microsoft Excel, has been
around since 2002. The latest and greatest version, packed with features for creating
and analyzing RF transmitter and receiver component chains, is called RF Cascade
Workbook™ (RFCW) ver L. RFCW™ 2008 brought, along with other new capabilities,
a major change where the components are arranged horizontally across the page, rather
than being stacked vertically. Occasionally, I receive a request to make the RFCW™ 2005
vertical layout an alternative to the horizontal layout. I decided instead to release
RFCW™ 2005 under a new name, "Wireless
System Workbook," and make it available at no cost - compliments of RF Cafe
advertisers and me. The only "price" you pay is having a small, persistent floating
window...
 $5,000 in 1956 currency is equivalent to
about $46,000 in 2020, per the U.S. Bureau of Labor Statistics' "Inflation Calculator."
That is the value of the amateur radio equipment used by
Mrs. Mary Burke in her work handling "an average of 3000 messages
per month, principally for service personnel overseas." For her tireless wireless
efforts, she was the first woman to win the coveted Edison Award Cup (sponsored
by General Electric). Most of Mrs. Burke's communications was via Morse code, where
she restrained herself to "about 30 words a minute to maintain accuracy". Way to
go, Mary...
 Herein lies the tale of my
LP Gas Tank and Supply Line Installation adventure: In mid-June (2026), I detected
a rather strong odor of LP gas in the vicinity of an 300-gallon underground storage
tank in my daughter's yard. I had detected it a few times before, usually after
a strong rain. My guess is that the gas permeated the soil during a dry spell, then
was forced out as water saturated the ground. LP gas if heavier than air, so it
would tend to prefer residence in the ground if its source was there. The tank,
of late 1980s vintage, is buried about 30 feet from the house, which in and of itself
is OK per code, but the disturbing part is that my grandson's play yard is right
over top of it. Previous attempts to "scare" the adults into relocating...
 Around the time this article was written,
the first wave of the solar and wind (which essentially is also solar) power generation
craze was settling in. A few small windmill generators popped up around where I
lived in the Annapolis, Maryland area, but they were mostly owned by hippie Earth
worshipers who eschewed modern conveniences and didn't need hot water for bathing
anyway. Most of that generation (pun intended) of windmills put out direct current
(DC - typically 12 or 24 volts). We knew a very nice older man and his wife who
lived "off the grid" and grew most of their produce and even kept a goat for milk
(they were clean people). They had some
photovoltaic (PV) solar cells...
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
 The
1-dB compression point, usually written P1dB, is a practical large-signal linearity
limit for RF and microwave components such as low-noise amplifiers, power amplifiers,
mixers, active frequency multipliers, driver stages, variable-gain amplifiers, attenuators,
limiters, isolators, filters, switches, and receiver front-end modules. It is the
input or output power level at which the measured gain has fallen 1 dB below the
gain predicted by the small-signal linear gain line. In symbols, if the small-signal
gain is GSS in dB, then at the 1-dB compression point: Pout(measured,
dBm) = Pin(dBm) + GSS(dB) - 1 dB When the input power at that condition
is quoted, it is called input...
 Anytime I see an airplane in a photograph,
my interest is immediately piqued to learn the story behind it - sort of like with
the "MPATI - Its Problems & Solutions" feature in the May 1963 edition of
Electronics World magazine. This "Aerial 'Private Eye' Traces TV Signals" story also involves
airplanes and television broadcasting, albeit in a completely different way. A couple
enterprising broadcast engineers created a company called Tele-Beam Industries,
in Napa, California, that measured and mapped TV signal strength in the region surrounding
transmission towers to provide the stations with information useful in marketing
and radiation characteristic planning. Signal strength...
 Two major radio events were covered in this
1954 issue of Radio & TV News magazine's monthly "Spot Radio News"
column - the rapid advance of microwave technology for building out
high capacity voice and television transmission systems, and the
ever-increasing number of new TV station operation license grants since the ending
of the Federal Communications Commission (FCC) moratorium in 1952. In 1944, the
FCC stopped issuing broadcast permits due to serious unforeseen interference from
co-location interference issues as post-war households enthusiastically adopted
TV. Unlike today's microwave relay networks, in the 1950s most systems were
still analog in nature. Coaxial...
 The first video below is my favorite. It
is a one-minute clip from a 1960s episode of "The
Twilight Zone" television show. It is an outrageous slam on amateur radio operators
by a family whose radio and TV shows are being interrupted by interference. Dad
looks out the window and sees what are actually television antennas on the guy's
roof and when Mom asks if there is anything they can do about the neighbor, he walks
toward the telephone saying he can at least check to find out whether neighbor man
has a license to operate. Mom then says, "Do you think you should, Stu? Those men
seem kind of...threatening somehow." Those d**n evil Hams! As you might expect if
your are familiar with the series...
 Empower RF Systems announces the release
of its new
Model 1240, a compact, high-performance RF amplifier module delivering a guaranteed
minimum of 200 watts across the 900-1700 MHz frequency range. Designed to address
the evolving demands of modern electronic warfare (EW) and counter-unmanned aerial
systems (C-UAS), the Model 1240 expands Empower RF's portfolio of tactically deployable,
high-reliability solutions. The Model 1240 is a full gain "smart module" built on
advanced GaN transistor technology, integrating comprehensive control and monitoring
features to ensure consistent RF performance under all environmental conditions.
What sets the Model 1240 apart is its strategically targeted frequency coverage.
The 900-1700 MHz range aligns...
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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.
 That
ultrasonic communications has not proved to be a reasonable means of transmitting
information from one location to another - even over fairly short distances - is
borne out by the obvious lack of such systems today. With all the technology available
in the form of electronics, mechanics, and software, if it were possible to efficiently
and effectively implement systems of ultrasonic communications, such devices would
be as common as the current plethora of wireless systems. Some early research efforts
at ultrasonic communications were published in a 1945 edition of Radio News
magazine. Regardless of the era, the electromagnetic frequency bands are...
 1945 or 2022? Seventy-seven years have passed
since this photo of a
vacuum tube manufacturing facility in China was taken. Given that most new vacuum
tubes are made in China, and that the labor work conditions have not changed much
in the intervening time period (except in high-profile plants like Foxconn where
Apple products are made), this might very likely represent a modern day operation.
BTW, most of the vacuum tubes not being made in China are made in Russia... to assure
their antiquated infrastructure has an ample supple of replacement parts. I say
that only partly in jest. The largest market for new vacuum tubes is music amplifier
equipment...
 The August 1972 issue of Popular Electronics
included a short quiz by William Shippee titled "Test
Your Knowledge of Semiconductors." I guessed wrong on question #2, but guessed
right by process of elimination on question #8 (although afterward I discovered
that in 2012 I had posted an article about the #8 device in Electronics World
magazine). Go ahead and take your best shot. You might be surprised at how much
you've forgotten if you don't work with transistors on a regular basis. I'll bet
Q2 has most people guessing, too...
 The ARRL (American Radio Relay League) might
be considered as one of the first app developers. At 50¢ and $1 per app, the price
was in-line with one of today's typical not-for-free Apple or Android app. A user
willing to shell out $4 for all six had at his fingertips calculators and reference
tables for capacitive and inductive reactance, resonant frequency, gain and power,
conductor amperage, transformer turns ratio, resistor, capacitor, and inductor series
and parallel combination, and other values. These six apps, dubbed "Lightning Calculators,"
were comprised of bit of cardboard, plastic, and a metal eyelet, not data bits.
Here is a for-real Type B "Lightning...
 Repair service businesses have always gotten
a bad rap for deliberately inflating part and labor costs - often deservingly so
- but it's a shame the honest brokers are dragged down by the scum
(or "gyps" as this article calls them). Come to think
of it, the word "gyp" is likely short for "gypsy," which is sure to offend someone
these days. Along with admonishing customers to beware of shyster servicemen, there
is an example of an orchestrated
"sting" operation whereby a radio set was intentionally "broken"
in a certain way with witnesses as to the fault, and then a couple dozen repair
services were called upon to troubleshoot and fix it, then present a bill for their...
 This 1954 issue of Radio-Electronics
magazine reported on the death of electronics communications pioneer
Major Edwin H. Armstrong. Most famously known for his wideband FM (frequency
modulation) scheme, Maj. Armstrong also developed the superheterodyne circuit,
the superregenerative circuit, and was an independent inventor of regeneration.
As with many prodigious, prolific inventors throughout the ages, he spent much time
and fortune battling legal claims against himself and against others. Interestingly,
the news item does not mention that Major Armstrong, who was famous for his daring
antics at the tops of extremely high antennas, died...
 Here is
Zenith Models 5D011-5D027 schematic and parts list as featured in a 1947 edition
of Radio News magazine. Unlike with most of the Radio Service Data Sheets,
this came from group of three which also included the Bendix Models 636A, C, D and
the Coronet Model C-2, al three of which are tabletop models. As mentioned many
times in the past, I post these online for the benefit of hobbyists looking for
information to assist in repairing or restoring vintage communication equipment...
 These two
electronics-themed comics appeared in a 1952 edition of Radio &
Television News magazine. In the early days of television, it was common in
comedy skits and in cartoons to have someone on a television show interact, to the
viewer's great shock, directly with the viewer or to reach out of the set and do
something, as in the first comic here. The Three Stooges show did that in a couple
shows. One in particular I remember was when they were doing plumbing in a house
and had water coming out of light sockets and telephones. The homeowners were watching
the TV with a film of Niagara Falls when suddenly water came gushing out of the...
 Both my father and grandfather were
stamp collectors - philatelists is the technical word - who dabbled in a recreational
way with commemoratives from foreign countries. Nearly all were canceled (used)
stamps that today, as back in their day, have no real value other than to someone
interested in history. Of course none are the rare types. I now possess many of
those stamps in an album that was painstakingly hand-illustrated and assembled to
arrange each stamp according to its country and issue date. At one time I, too,
dabbled in the hobby, having collected many plate blocks and special issue U.S.
stamps in the 1970s and 1980s, along with purchasing a...
 My first thought when seeing the cover for
this December 1936 edition of Radio-Craft magazine was that it was an April
Fools gag, but it turns out the
"Hat" being worn by the radio receiver's designer is a loop antenna for AM reception.
Ya' know, he does look like he could be a suicide bomber.
In a way it is the opposite of a tinfoil hat in that this headgear invites electromagnetic
energy around the wearer's head rather than shielding it. Back in 1936, being seen
in public donning a contraption like this radio would have been akin to wearing
Google Glass (a failed concept) a few years ago - you'd be a superhero to fellow
nerds, and just be confirming your...
 This custom made
Analog Engineering theme crossword puzzle for May 22nd is provided
compliments of RF Cafe. All RF Cafe crossword puzzles are custom made by me,
Kirt Blattenberger, and have only words and clues related to RF, microwave, and
mm-wave engineering, optics, mathematics, chemistry, physics, and other
technical subjects. As always, this crossword puzzle contains no names of
politicians, mountain ranges, exotic foods or plants, movie stars, or anything
of the sort unless it/he/she is related to this puzzle's technology theme (e.g.,
Reginald Denny or the Tunguska event in Siberia). The technically inclined
cruciverbalists amongst us will appreciate...
 This article describing the "Auto-Sembly"
technique for fully automated processing of electronic assemblies appeared in the
1954 issue of Radio & Television News magazine. Auto-Sembly was developed by
the U.S. Army Signal Corps, and might have first appeared in print in the 1951 issue
of Electronics magazine. Single-sided printed circuit boards (PCBs) with components
mounted on the far side were hot-dipped in a solder bath. All components were through-hole
at the time since surface mount was not in the picture yet. The large mass (weight)
and relatively low adhesion strength of copper foil to the substrates would not
reliably hold the...
 Don't let the title fool you. This is not
a "bees-birds-and-flowers
routine" being provided to Barney by his boss, Mac. It turns out to be a brief
introduction into the fine art of troubleshooting intermittent problems in radio
and television circuits. As is usually the case, while the specifics of the scenarios
Mac describes might not apply to your challenge at hand, the general philosophy
always does. It is basically the old process of elimination where after rapping
components mechanically and/or heating or cooling them in hopes of observing a tell-tale
change in performance, the next step is to divide the suspected circuit portion
in half (electrically, but sometimes...
 Some of the earliest television display
schemes were mechanically scanned light projection systems rather than electronically
raster scanned cathode ray tubes. This 1930 vintage article from Radio News
magazine reports on a scheme developed by Arthur Watson whereby a specially formed
rotating Monel disk served as the rotating reflecting surface to produce the light
scanning action. This invention was hailed as a breakthrough that would finally
make commercial TV available to the masses.
Mechanical televisions worked by transmitting scanned images of the original
subject in the form of amplitude modulated electrical signals whose voltage was
determined by...
 Atomic energy research came to the forefront
of public awareness in 1945 following the detonation of the world's first nuclear
bombs. X-rays had been studied for decades and uses had been developed for medical
and industrial inspection purposes, but the harmful effects of low level exposure
over long periods of time were still largely undetermined. Some people, like the
author of this report from a 1949 edition of Radio & Television News
magazine, believed "man's life is shortened by exposure to any amount of
radioactivity." That was a rather extreme and alarmist statement to make in
an article whose purpose was ostensibly to encourage engineers... |
