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 In the opening scene of "Gladiators," Quintus
remarks to Maximus (Russell Crowe), "A people should
know when they've been conquered." Such truth is applicable to society today regarding
ubiquitous surveillance. Less than two decades ago the media was
filled with stories of outrage over the discovery of some new form of monitoring
and reporting system having been installed on highways, in shopping malls, along
sidewalks, even bathrooms. Since the 9/11 terrorist attacks, anything goes with
government snooping. Count the numbers of freedoms you have lost and the inconveniences
suffered because of those 19 men with no identifiable common cause
(wouldn't want to profile). This story from 1956 shows
how long stealth installation...
 I wonder why today's editions of the ARRL's
QST magazine does not have a column dedicated to the "YL" (Young
Lady, or female in general) contingent of the amateur radio realm? Ham radio,
as most -if not all - historically male-dominated hobbies has fairly significant
outreach efforts to try attracting women into activities. My Model Aviation
magazine has a monthly column written by a lady whose enthusiasm for model airplanes
equals that of most males - and she's funny to boot! - but it is not dedicated to
female modelers. If there is a girl or woman present at a competition, she is almost
guaranteed to receive coverage...
 The December 1947 issue of Radio News
and the February 1954 issue of Radio & Television News published these
electronics-themed comics. Humor evolves over time, which is apparent when you
look over these and many of the other comics from these vintage electronics magazines.
The AVC comic is the best, IMHO. For those of you not around in the olden days of
vacuum tubes, tapping on a tube would often make it work properly again, either
because of a dirty contact in the socket or crud that had accumulated on the screen
grid. I give this batch a score of about 7 out of 10, but you might think otherwise.
There is a growing list of other comics at the bottom of the page. Enjoy...
 How RF circuits work have long been referred
to as "black magic,... even sometimes by people who fully understand
the theory behind the craft. To me the ways in which a transmission line - be it
coaxial cable, microstrip, or waveguide - can be manipulated and controlled with
various combinations of lengths and terminations is what most qualifies as "magic."
Sure, I know the equations and understand (mostly) what's happening with incident
and reflected waves, etc., and how the impedance and admittance circles of a Smith
chart graphically trace out what's happening, but you have to admit there's something
wonderfully mystical about it all...
 I remember hearing a long time ago about
"The Thing"
- a passive bugging device discovered within a wooden Great Seal gifted to the U.S.
Embassy in Moscow. This 1962 Electronics Illustrated magazine feature explores
the ingenious, battery-less Soviet listening device. Far from a conventional electronic
bug, this passive device utilized a specialized resonant cavity and a diaphragm
that modulated an external 1600 MHz radio beam, essentially acting as an echo-based
microphone that was incredibly difficult to detect. While the article highlights
the device's diabolical simplicity and sensitivity, it contains no mention of the
U-2 incident or Gary Powers; notably, historical records clarify that Ambassador
Lodge displayed the device in 1960 to expose Soviet espionage...
 Based on beleaguered wife Sylvia Kohler's
mention of GE's Electronics Park in this story (surely a fable... or not), she and
unintentional antagonist, superheterodyne hubby (aka "Happy Boy," but we know him
as Popular Electronics cartoonist
Carl Kohler) probably lived in the Syracuse, NY, area. Electronics
Park existed during the hey days of General Electric when the sprawling campus ,
just north of I-90, designed and manufactured a plethora of both household and military
electronics products. GE's Electronics Laboratory ("E-Labs") was the company's pride
and joy. Today, a tiny portion of Electronics Park is still occupied by Lockheed
Martin, who bought that GE division in the 1990s, and the rest belongs the city.
But I digress... enjoy the story (her reason for referring to hubby as a Superheterodyne
is highlighted)...
 Multielement quad antennas are as popular
today as they were in 1967 when this article appeared in the ARRL's QST
magazine. That is not to say they are common. This particular design is for the
10-, 15-, and 20-meters bands, all three
of which are still in use today. If you build a multielement quad as shown here,
you might want to find a substitute for the bamboo frame members; aluminum tubing
is pretty cheap, but if you use metal, you'll need to use insulators at the connection
points. Formulas are provided for determining element lengths and director and reflector...
 This Radio Service Data Sheet from a 1932
issue of Radio-Craft magazine provides schematics and parts lists for
Silver-Marshall Model 727-DC Battery-Operated Superheterodyne
receiver. Most - if not all - electronics servicemen had subscriptions to these
magazines because they were a ready source of not just these service sheets, but
because of the extensive articles offering advice on servicing radios and televisions.
In fact, many electronics manufacturers had a policy of supplying service data only
to bona fide shops. A large list is included at the bottom of the page of similar
documents from vintage receiver schematics, troubleshooting tips, and alignment
procedures...
 There is something about these proposed
shorthand circuit symbols that reminds me of the IEEE digital
logic symbols using the distinctive shape (the traditional format) versus the newer
rectangular shape format. The set is quite extensive when all the different flavors
of combinatorial blocks - flip-flops, timers, counters, shift registers, encoders,
decoders, etc. - are included. My personal preference, you might guess, is the original
format with distinctive shapes. Although I do not do a lot of digital work, it is
easier for me to follow the signal flow and mentally perform the logic operations
with the distinctive shapes. But I digress. This article from a 1947 issue of
QST magazine introduces...
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You
Covered."
 Mac's young technician sidekick Barney decides
to one-up the
do-it-yourself television repair books that were flooding magazine
pages those days by writing a series of do-it-yourself surgery books. He figures
if the other guys can get rich by convincing Joe Sixpack that he can easily fix
problems in his TV set - where potentially lethal voltages lurk in every corner
- in as little as five minutes while saving hundreds of dollars from those rascally
shop owners, then surely those same people might buy his books for removing your
own appendix or tonsils. Deny the greedy doctors...
 This week's
Science & Engineering Crossword Puzzle has a special message
included that has to do with why you might be off work on Monday for a holiday.
Oh, and it also happens to be the world's most revered religious time of commemoration,
which to the delight of some and to the sorrow of others, is rapidly fading into
the shadows of time. The colorful "no-letter" squares were inspired by the type
of candy I am eating as I make the puzzle. As always all the other words are from
a hand assembled file of thousands of terms from science, engineering, mathematics,
chemistry, astronomy, etc. 7 Across + 15 Across to all...
 It really was not all that long ago when
wiring images for news stories literally meant
transmitting photographs over a twisted pair of telephone lines
either to a fax machine or to a computer on standby waiting for incoming files.
Videocasts were being regularly performed via satellite of ground relay microwave
stations since the 1960s, but most still shots were sent via phone lines. For the
last decade and a half, both still shots and videos have been transmitted as a routine
matter via camera-equipped cellphones, and as with most technologies we have quickly
become so accustomed to the convenience that memories of the old ways are quickly
(even thankfully) forgotten. This article from a 1936 edition of Radio-Craft
magazine describes one of the really early systems. Notice that coupling to the
telephone line is...
 On
sale through the end of June! Werbel's new
WM3PD-6-18-S, 3-way Wilkinson divider that operates from 6 to 18 GHz.
It is part of Werbel Microwave's catalog of splitters that offer a wide range of
port count and frequency ranges. Its compact aluminum enclosure measures 1.57 x
1.57 x 0.38 inches. The device is RoHS compliant, however it may be specially
ordered with lead solder. Return loss 14 dB typical input, 15 dB typical
output. Insertion loss above 4.8 dB is 0.3 dB typical. Isolation 23 dB
typical. Phase balance 3.4° typical. Designed and assembled in the USA. "No Worries
with Werbel!"
 Velocity modulation, aka deflection modulation,
of electronic images was evidently considered by some engineers to be potentially
disruptive technology when this article was published in a 1951 issue of Radio &
Television News magazine. You can see from the pictures that the result is
an image that today's digital software would render with an "emboss'" technique.
More vertical relief seems to be generated with the analog velocity modulation technique
compared to what my graphics program does when embossing the original photo. At
the bottom of the page is a velocity modulation video demonstration found on YouTube...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products such as
RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters,
and a 15-band programmable filter (5 MHz-8 GHz). Since the conception
of WFT, we have introduced products that have been purchased by a wide range of
customers, from hobbyists to education facilities to government agencies. Worldwide
customers include Europe, Australia, and Asia. Please contact Windfreak today to
learn how they might help you with your current project.
 Fortunately, there is a constant flow of
people newly interested in electronics who are seeking information on basic principles.
Some will find an article this one on
Ohm's law fundamentals and decide maybe being just a user of electronics
is good enough. Others will, as did you and I, read this kind of material and be
amazed at how ultimately predictable electrical circuit parameters are. If he or
she continues and launches into a career in electronics or electrical engineering,
it won't be long before he or she will, as do you...
 Whilst reading this Carl Kohler technodrama
entitled "Thin Air My Foot!," I happened upon this word new to me: "din,"
as in "It was dinned into me." OK, maybe you already knew that, but surely I should
have been aware of its alternate meaning other than being a loud noise ("the agitated
cat made quite a din."). Fortunately, I am not subject to a household of people
who refuse to put things back in their respective places when through with them,
but this tale of woe tells what might be a familiar scenario to you. To be honest,
this could have been written about me as a boy - before the U.S. Air Force taught
me a thing or two about organization and neatness - since I continually frustrated
my father by leaving his tools (and hardware and lumber and paint) scattered in
forgotten places around the house and yard...
 Antenna radiation (beam) patterns published
by manufacturers are obtained under ideal - or close to ideal - conditions with
a carefully prepared and calibrated open air test site (OATS) or an enclosed anechoic
chamber. Multipath, imperfect earth ground, obstacles both manmade and natural,
misshapen elements, poor VSWR, antenna orientation (in both azimuth and elevation)
are among the many factors which produce real-world operational results that do
not jive with a manufacturer's datasheet. Without employing some far field 3-dimensional
field strength scheme see
Drone-Based Field Measurement System™), there is no way to obtain
a complete picture of how your antenna performs in all directions...
 It has been quite a while since posting
a
Carl & Jerry adventure tale. The teenage-neighbors-cum-Ham-radio-operators-cum-electronics-hobbyists-cum-amateur-detectives-cum-pranksters
are the creation of John T. Frye. He published a monthly episode in Popular
Electronics magazine. Mr. Frye is also the author of the
Mac's Radio Service Shop series of instructional stories
that ran in Radio & Television News magazine. This adventure is quite
a digression from the typical storyline in that the boys actually engage in a bit
of deceit in order to save face based on a bet...
|
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AI Eroding Critical Thinking
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Approves Charter's $34.5B Acquisition of Cox
• Amazon
Might Buy Globalstar
• AI Could End
Online Anonymity (or falsely identify)
• How
Test and Measurement Will Evolve in 2026
 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.
 Mixing a little fun with learning has always
been a good motivation for students. I have written in the past about a particular
electronic circuits professor I had that liked to play practical jokes during lessons
and exams. Including gag options on a multiple choice test is a great way to inject
a bit of tension-easing levity while at the same time eliminating one or more opportunities
to guess at a wrong answer (although no relief for the truly clueless). I sometimes
do that on the RF Cafe Quizzes that I generate. Radio-Craft printed a large
bunch of such quiz questions under the title "Radio
WittiQuiz," where the questions and answers were provided by readers. Here
is one from October 1938...
 In these times of communists and Marxists
(and other "-ists") infiltrating high positions of American government and destroying
our hard-won legacy of freedom, compassion, traditional family values, hard work,
and patriotism, this
Independence
Day theme crossword puzzle is created to celebrate our heritage and resist the
corrupters. The Cancel Culture mobs will never dissuade our staff (Melanie and me)
here at RF Cafe! Clues with an asterisk (*) are related to the puzzle's theme. All
crossword puzzles use a personally built dictionary of thousands of 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...
 This
Science
Theme crossword puzzle for August 22nd, 2021, contains only words and clues
related to engineering, mathematics, chemistry, physics, and other technical words.
As always, this crossword 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., Hedy Lamarr or the Bikini Atoll). The technically
inclined cruciverbalists amongst us will appreciate the effort. Enjoy!
 Unless I find one I missed from my collection
of vintage Popular Electronics magazines, this could be the last Friday electronics
quiz for a while. All of the quizzes were created by Robert p. Balin, and range
in difficulty from relatively easy to head scratchers (for typical test takers like myownself).
Sometimes modern readers will be stumped by references to dated drawings and/or terms
like vacuum tubes and CRTs (which are themselves vacuum tubes, of course). This
Electronics Geometry Quiz might require a Millennial handicap on item "E" if you
spaz out over the picture, but if you get the other nine correct, you'll get all ten
by default. This is probably...
 This gives a whole new meaning to "Political
Science." Vaccinated people have been generating and shedding variants of COVID-19.
WHO designates each new variant with progressive letters in the Greek alphabet,
beginning with Alpha. Until a few days ago they were up to the Nu variant. Next
came Omicron. "What
happened to Xi?" you might reasonably ask. It so happens that Xi (Jinping) is
the name of China's dictator, so "the Science" we are admonished to listen
to decided to omit it. Now we need the Ministry of Truth to replace all former references
to Xi (Ξ, ξ) with some other symbol. Let me be the first to suggest a spiked
virus icon  . Damping ratio henceforth
is written as = 2.5
rather than the traditional ξ=2.5. Similarly there is the
baryon (rather than the Xi baryon),
the Riemann function, potential difference is
volts, the Scientific Research Honor Society
is now Sigma . You get the idea...
 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)...
 Humor in 1933 was evidently very different
than it is today. This is part of what was in the April edition of the ARRL's QST
magazine from that year. Unlike the unannounced "April
Fools" features that may or may not appear in a given year's April issue nowadays
(the April 2022 issue of QST has a gag article on page 40 - the page 38
article is actually real), much ado was made over the gags back in the day. You
might have noticed the humor in some of the older electronics-themed comics also
sometimes invokes the "what am I missing?" response. Shown below on the left is
the gag table of contents page and on the right is the "real" table of contents.
I get the thumbing the nose by the little dude in the margin, and I get the play
on American Radio Relay League, but what the hey does "Liberian Dog-Apple Growing"
mean? Any ideas? Maybe you'll be able to appreciate the intended humor here...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
 Here are a few of my favorite
Christmas music
videos. They include an eclectic mix of Cloverton, the Trans-Siberian Orchestra,
an unlikely duet sung by Bing Crosby and David Bowie, and Casting Crowns. Watching
the instruments being played really enhances the effect of the song. I used to have
the videos embedded in this page for easy viewing all in one place, but each year
on some of them I have to go find new hosting location because the previous year's
had been removed. This time I am just linking to the YouTube (and other) web pages.
The U.S. Air Force Band performance at the Smithsonian Air and Space Museum is my
newest addition for 2020...
 Prior to phasing-based single sideband generation
circuits, a brute force filtering of the unwanted sideband and carrier signals was
required. Depending on how well the carrier was suppressed, more than half the total
signal power could be lost. According to author Jack Brown in this "Commercial
Aspects of Single-Sideband" article from a 1956 issue of Radio & Television
News magazine, it had only been since the mid 1940s that wide-band audio-frequency
phase-shift networks were even feasible. An ideal implementation of a single-sideband
suppressed-carrier modulator (SSB-SC) would result in 100% efficiency, but typical
results are in the 80% range...
 There is a twofer on this page - a feature
article and a couple related
electronics-themed comics. Point-to-point wiring of electronics
assemblies is rarely seen these days. For that matter, the use of leaded components
is rarely seen these days. The advent of printed circuit boards was a real breakthrough
concept when they became commercially viable in the 1950s. As the comic at the bottom
of the page suggests, many people did not even know what a printed circuit board
was. The air traffic control radar unit that I worked on in the USAF had all point-to-point
wiring in a trailer-full of chassis. Terminal strips and bus strips, bifurcated
terminals, tube socket terminals, and studs from relays and switches were the connection
points...
 I remember in one of my circuits classes
in college when the
gyrator was introduced, and I thought it was an ingenious invention. The gyrator
circuit, implemented with an opamp and a couple resistors and capacitors, changed
its measured impedance type from that of a capacitance to that of an inductance.
That is, its impedance represents an R + jX Ω format. Frequency limits
are imposed by a combination of the self-resonant frequencies of the resistors and
capacitors as well as the GBWP of the opamp, and power handling is primarily limited
by the opamp's voltage and current capabilities. You might ask why, with all those
constraints on its use you would even want to use a gyrator circuit? The answer
is that within its limitations, the gyrator often represents a less expensive and
more compact version of a physical inductor. This is particularly true with ICs
where, unless it is a MMIC operating in the tens of gigahertz region, there is no
space available on the die for a printed metallic inductor with enough inductance
to be useful. Any inductors would need to be mounted off-chip on the PCB with I/O
pins interfacing to the IC. Gyrators...
 Not many of us are still using multimeters
with analog movements for the display. The convenience and fool-proof-ness of digital
multimeters (DMM) makes them the obvious choice for the majority of people. In fact,
the vast majority of my voltage, current, and resistance measurements are made with
a DMM. I still have a couple analog meters which I bought decades ago when first
entering the field of electricity and electronics. The crudest type of indicator
I have is on my early 1970's vintage Square D Wigginton Model 5008 Voltage
Tester with a solenoid indicator. This "Measurement
of Meter Resistance" article in a 1960 issue of Electronics World magazine
was needed sagacity at the time because the internal resistance (impedance) of the
meter and the analog indicator movement might be sufficiently low enough to load
down the circuit being measured to the point where an erroneous measurement is made.
The presence of a parallel resistance causes the circuit under test...
 Thyratrons, klystrons, and magnetrons I've
heard of, but
trochotrons, charactrons, tonotrons I ain't heard of. That made this quiz more
of a learning exercise for me than a test of any sort of knowledge possessed. Heck,
I thought an 'ignitron' was a pejorative term for a really dumb techie wannabe.
In all there are 17 types of '-tron' devices given for which to match from a list
of descriptions. You'll probably do better than I did on this quiz that appeared
in the October 1963 issue of Electronics World magazine.
 OK, I give up. What is a "pukka amateur?"
According to an online dictionary: pukka, adj (esp in India) 1. properly or perfectly
done, constructed, etc. a pukka road 2. genuine pukka sahib. Next up: A
Blattnerphone. That sounds an awful lot like Blattenberger, or
maybe more like Blattnerberger. Anyway, a Blattnerphone was an early attempt at
recording sound on a steel tape. I thought my native language was English, but evidently
there are still some good words to learn. If you read enough vintage magazines from
the first half of the 20th century, you will run across many words and phrases that
are still in the Merriam-Webster dictionary, but you hardly ever see or hear them
used anymore... |
