See Page 1 | 2 | 3 | 4 | of the July 2024
homepage archives. Friday the 5th
 The
Lightning Protection Institute (LPI)has been around for a long time; in fact,
it might have been informally founded by Benjamin Franklin ;-) Last year while working
on an installation plan for a friend's solar panel array and equipment room, I found
lots of useful info on the LPI website for best practices of lightning protection.
I was surprised to learn that there was still disagreement among experts as to whether
a raised, grounded surface like the metal roof onto which the photovoltaic (PV)
arrays are mounted tended to reduce or increase the likelihood of a lightning strike.
There are good theoretical arguments on both sides. I tend to think the raised,
broad surface decreases the cloud-to-ground potential and disperses the charge across
a larger area, thus reducing chance of a strike. There is also disagreement whether
the ground for the PV array should be physically connected to the ground...
 Parts 1 and 2 of this series covered the
theory of nuclear physics and laboratory investigation devices. This final installation
talks about commercially available test instruments for detecting and measuring
nuclear radiation levels. My introduction to
Geiger counters was in the old The Adventures of Superman television show where
they were used by villains to verify that their stash of Kryptonite would be sufficient
to disable our superhero. I could not find anywhere whether Kryptonite's emission
type is alpha particles (helium nucleus; i.e., 2 protons and 2 neutrons), beta particles
(electron), gamma rays (electromagnetic waves), or some other form. Multiple designs
of detectors are used based on radiation type and strength to be measured...
 Transcat | Axiom Test Equipment, an electronic
test equipment rental company has published a new blog post that covers how
thermal imagers can be used to detect temperature overloads in electrical and
mechanical equipment, and what to look for when selecting the one for your project.
Electronic performance is affected by temperature, with heat sources inside and
outside a device or system. High-power amplifiers exhibit rises in temperature from
the heat of semiconductors and must be equipped with cooling for safety and longevity.
Other electronic designs can suffer performance degradations when placed too close
to heat sources or even when exposed to sunlight. Fortunately, the temperatures
of electronic equipment can be measured quickly and accurately without making physical
contact, with the aid of IR...
 It is the opinion of many historians that
in order to better understand the present, you need to know the past. Searching
for one's roots in this world is big business. Online family tree type websites
are used by thousands of people to research their family histories, and some services
don't come cheap. You can even pay someone to dig into your past to assimilate all
available information and put it in a bound, printed volume. Here on RF Cafe, I
research and post a lot of our profession's past. While the individual topics themselves
might not bear significantly on the present, having an insight into the people's
mindsets and progression of technology is - or should be - motivating. No, most
modern
televisions do not process analog signals, use a CRT, have vertical and horizontal
hold adjustments, but then not too far in the future most televisions won't be much
like they are now. Engineers and technicians of today's world have a distinct advantage
over prior years' innovators because with enough ingenuity and fortitude...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols
available for RF, analog, and digital system and schematic drawings! Every object
has been built to fit proportionally on the provided A-, B- and C-size drawing page
templates (or can use your own). Symbols are provided for equipment racks and test
equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous
versions, these are NOT Stencils, but instead are all contained on tabbed pages
within a single Visio document. That puts everything in front of you in its full
glory. Just copy and paste what you need on your drawing...
Thursday the 4th
 Seeing a reader name of Qutaiba Bassim El-Dhuwaib
would not seem unusual in one of today's technical magazines, but having it appear
in a 1964 issue of Radio-Electronics was definitely a rarity. Such was
the case with this first "Black
Box" circuit challenge submitted by the aforementioned subscriber. I took a
WAG at the answer and got it right, but without considering the theory behind it.
Fortunately, Mr. El-Dhuwaib provides that gory detail for us. It is a pretty clever
scheme for effecting a phase shift while not affecting the magnitude. The second
mystery circuit requires being familiar with types of meter movements commonly used
in DC and AC voltmeters. Having begun in the craft prior to the advent of digital
multimeters (that includes me) helps. Such circuits were probably more intuitive
to designers in the days of analog...
 Here is a type of chart I don't recall seeing
before. This
Tolerance Calculator Graph makes it very easy to quickly determine the upper
and lower extremes of tolerance values for resistors, capacitors, inductors, etc.
It was published in a 1963 issue of Electronics World magazine, and can
actually be used to find the limits for any number, regardless of units. This is
one example of where a physical visual aid can still yield results faster than punching
numbers into a calculator, if a number with just a couple significant figures of
precision is sufficient...
 Back in May, the American Radio Relay League
(ARRL), the world's largest amateur radio organization, reported a
major service
disruption. Not a lot of information has been divulged, but it appears to involve
member and processing information. Even the phone system was down for a while. Several
services, such as Logbook of The World® and the ARRL Learning Center, were affected,
as well as mailing of hard-copy magazine editions (which indicates member addresses
might have been involved). Per the ARRL:
"On or around May 12, 2024, ARRL was the victim of a sophisticated network attack
by a malicious international cyber group. ARRL immediately involved the FBI and
engaged with third party experts to investigate. This serious incident was extensive
and categorized by the FBI as “unique,” compromising network devices, servers, cloud-based
systems, and PCs. ARRL management quickly established an incident response team.
This has led to an extensive effort to contain and remediate the networks, restore
servers, and staff are beginning the testing of applications and interfaces to ensure
proper operation."
 This is the
electronics market prediction for Denmark, circa 1966. It was part of a comprehensive
assessment by the editors of Electronics magazine of the state of commercial,
military, and consumer electronics at the end of 1965. Unless you can find a news
story on the state of the industry, detailed reports must be purchased from research
companies like Statista. Their website has a lot of charts on Denmark's current
electronics market showing revenue in the consumer electronics segment amounts of
US$1,020 million in 2018...
 In
CONGRESS, July 4, 1776.
The
unanimous Declaration of the thirteen united States of America, When in
the Course of human events, it becomes necessary for one people to dissolve the
political bands which have connected them with another, and to assume among the
powers of the earth, the separate and equal station to which the Laws of Nature
and of Nature's God entitle them, a decent respect to the opinions of mankind requires
that they should declare the causes which impel them to the separation.
We hold these truths to be self-evident, that
all men are created equal, that they are endowed by their Creator with certain unalienable
Rights, that among these are Life, Liberty and the pursuit of Happiness. -- That
to secure these rights, Governments are instituted among Men, deriving their just
powers from the consent of the governed, --
That whenever any Form of Government becomes
destructive of these ends, it is the Right of the People to alter or to abolish
it, and to institute new Government, laying its foundation on such principles and
organizing its powers in such form, as to them shall seem most likely to effect
their Safety and Happiness. Prudence, indeed, will dictate that Governments
long established should not be changed for light and transient causes; and accordingly
all experience hath shewn, that mankind are more disposed to suffer, while evils
are sufferable, than to right themselves by abolishing the forms to which they are
accustomed. But when a long train of abuses and usurpations, pursuing invariably
the same Object evinces a design to reduce them under absolute Despotism, it is
their right, it is their duty, to throw off such Government, and to provide new
Guards for their future security. -- Such has been the patient sufferance of these
Colonies; and such is now the necessity which constrains them to alter their former
Systems of Government. The history of the present King of Great Britain is a history
of repeated injuries and usurpations, all having in direct object the establishment
of an absolute Tyranny over these States...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 280k
per year (in eight locations on each page, with >17k pages)...
Wednesday the 3rd
 In 1967, when this National Radio Institute
(NRI) advertisement appeared in Radio-Electronics magazine, allowing
tattoos to be visible on people representing a company's interest was almost
never done. Harley Davidson might have allowed it, or maybe Old Spice after shave
lotion, but certainly not typical from an educational establishment pitching electronics
instruction. The dude in this ad has a clearly, intentionally visible "tat" on his
right arm. It is no accident because the shirt sleeves are rolled up when they don't
need to be, and the right sleeve is up twice as far as the left sleeve. The photographers
wanted readers to see it. My interpretation of it is "D. S.," and then some illegible
character at the end (maybe "jr"?). Any guesses as to what it might be?
 "Researchers have successfully manipulated
the structural properties of magnetite using
light-induced phase transitions. This technique uncovered hidden phases of magnetite,
paving the way for new approaches to material manipulation in electronics. 'Some
time ago, we showed that it is possible to induce an inverse phase transition in
magnetite,' says physicist Fabrizio Carbone at EPFL. 'It's as if you took water
and you could turn it into ice by putting energy into it with a laser. This is counterintuitive
as normally to freeze water you cool it down, i.e. remove energy from it.' The study
discovered that using specific light wavelengths for photoexcitation the system
can drive magnetite..."
 You just never know when your number is
going to be called. People who engage in a dangerous activity they love often claim
that if they are going to die in an accident, it would preferably be while engaging
in that activity. It really sucks to die like Army-Air Force Lt. Henry B. Harris
who was an accomplished instrument flight research pilot (and noted
Ham radio operator).
Rather than expiring in an airplane, he met his end as a passenger in a car that
was towing some other pilot in a glider. The story is told in the August 1934 issue
of the ARRL's QST magazine...
 TEMWELL Corporation is a worldwide expert
and company in designing & manufacturing RF helical bandpass filters since 1994.
For the entire
month of July, you will receive a discount of 50% off all filters! We have designed
and built up over 5000 completed spec sheets online for displaying all our excellent
capability. Furthermore, in order to satisfy more RF engineers and develop projects
all over the world, our engineers have designed diplexers and duplexers for 5G,
VHF, UHF, TETRA cavity duplexers, helix cavity diplexers, LTE low PIM diplexers,
and coaxial duplexers ...
 James Clerk Maxwell's inception of the theory
of electromagnetic radiation is compared in this 1930 Radio-Craft magazine
article to if Christopher Columbus had conceptualized the existence of America and
mapped its features based solely on observations of how the known oceans and land
masses interacted. I have always been amazed at the ability of people who formulate
entirely new theories of science, finance, medicine, etc., and manage to detail
and support their ideas with hard data and mathematics. Einstein did so with relativity,
Dalton did so with atomic structure, Darwin did so with evolution, Pasteur did so
with germ theory; the list is long. There are lots of geniuses out there, but a
relative few change the world...
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils
available for RF, analog, and digital system and schematic drawings! Every stencil
symbol has been built to fit proportionally on the included A-, B-, and C-size drawing
page templates (or use your own page if preferred). Components are provided for
system block diagrams, conceptual drawings, schematics, test equipment, racks, and
more. Page templates are provided with a preset scale (changeable) for a good presentation
that can incorporate all provided symbols...
Tuesday the 2nd
 When I think of the
first space station, what comes to mind is the Russian Salyut 1 (c1971),
and then America's Skylab (c1973). This "News Briefs" feature in the December 1960
issue of Radio-Electronics magazine claims there was an earlier space station
- the Courier. OK, NASA might have called it a space station, but it wasn't a manned
space station like the aforementioned were. It launched in early October of that
year. Courier 1B (its full designation) was the world's first active repeater
satellite, which could receive a message (text, image, voice, or data), store it,
then transmit it later. A few details regarding its operation are provided. Also
in the news was research into using "ball lightning" as a weapon. That's right,
shoot a ball of searing hot plasma toward the enemy to obliterate it - or at least
scare the bejeebers...
 "Chinese scientists say they have developed
a groundbreaking material that could
give storage chips an almost infinite lifespan. This new type of ferroelectric
material could potentially reduce data center costs and have applications in deep-sea
exploration or aerospace in the future. Ferroelectric materials are commonly used
to make chips for storage and sensing purposes that are critical to artificial intelligence
and other hi-tech areas hit by U.S. sanctions, as a tech war plays out between the
United States and China..."
 TotalTemp Technology's John Booher sent me
this item he saw on "The Vault of the Atomic
Space Age" Facebook page. Not being a Facebook follower (except for looking
for stuff to buy on the Marketplace page), I tried to find the drawing on the website,
but there are so many that I never did see it. There are lots of really great vintage
photos, advertisements, and artwork in an endlessly scrolling list. Although not
mentioned, that antenna looks a lot like Bell Lab's "Sugar
Scoop" antenna which was built around 1960 to communicate with early satellites,
but also ended up discovering the cosmic microwave background radiation (CMBR) noise
form the Big Bang...
 Withwave's
Non-Magnetic Coaxial Connectors are widely used in applications that experience
strong magnetic field can cause interference or introduce errors such as quantum
computing, magnetic resonance imaging(MRI) equipment, the aerospace industry. Constructed
of beryllium copper (BeCu) and plating, they features a DC to 40 GHz frequency range
and are available in various interface sizes. Applications include quantum computing
, military & space, and medical devices (MRI). Withwave is a leading designer
and developer of a broad range of RF, microwave, and millimeter-wave test solutions
and subsystems with a focus on electromagnetic field...
 Here is the
ECA (Electronic Corporation of America) Model 108 schematic and parts list as
featured in a 1947 edition of Radio-Craft magazine. It had a very unique
tabletop chassis design made of formable "plastic-like" Bakelite material. The front
panel contains a matrix of slits for the speaker area, and the frequency strip at
the top is behind a curved clear window. The speaker driver was a powerful push-pull
design. 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...
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...
Monday the 1st
 Based on three major stories on
tunnel diodes in 1960 issues of Radio-Electronics magazine, you might
think the relatively new negative resistance device was a big deal. It was. Known
also as an Esaki diode, the tunnel diode, named after its inventor, Leo Esaki, in
1957, is a two-terminal semiconductor device which exhibits negative resistance
over a certain range of voltage and currents, making it useful as an oscillator
and amplifier. Its cost compared to a transistor is much lower, and its operational
frequency is much higher than that of a transistor (at least it was so back in 1960
and for a couple decades afterwards). The tunnel diode works on the quantum tunneling
principle Big plans were made for using tunnel diodes as local oscillators and even
amplifiers in radios and radars. Their relatively low voltage and current handling
ability caused them to be preferred less than the high power handling Gunn diode,
which emerged just a few years later.
 The newest addition to RF Cafe's spreadsheet
(Excel) based engineering and science calculator -
Espresso Engineering Workbook™ (click to download) is a functional Smith Chart
that plots a series of user-defined impedance points. RF Cafe Espresso Engineering
Workbook™ is provided at no cost, compliments of my generous sponsors. The original
calculators are included, but with a vastly expanded and improved user interface.
Error-trapped user input cells help prevent entry of invalid values. An extensive
use of Visual Basic for Applications functions now do most of the heavy lifting
with calculations, and facilitates a wide user-selectable choice of units for voltage,
frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page
of units conversion calculators is included. A particularly handy feature is the
ability to specify the the number of significant digits to display. Drop-down menus
are provided for convenience...
 Have you ever made a power or noise figure
measurement and had to scratch your head over why the reported value made absolutely
no sense? How about measuring a positive gain value through a passive device? I
have experienced this sort of nonsensical phenomenon on more than one occasion,
and to my recollection every time the cause was stray frequencies - often oscillations
- mixed in with the intended signal. This app note from a 1952 issue of the ARRL's
QST magazine addresses the issue in regard to
impedance matching
networks that are wideband enough to support RF energy that is outside the band
being tuned - or even unexpected inband signals - with a simple method of avoiding
such surprises...
 TiVO systems are just the latest incarnation
of programmable systems for recording television programs for playback at a later
time. In 1972, Sears, Roebuck & Company announced "plans to market the first
integrated videotape cartridge recording-playback unit for the home." It was part
of a package that included a specially designed 25" color TV, a camera, and a recording
/ playback unit. The projected price of $1,600 is equivalent to $12,006 in 2024
money. As always, it was the early adopter technophiles who financed the engineering
and market research that eventually led to the sub-$1,000 monster LED TVs and $200
TiVO units of today.
Earned engineering degrees had leveled off in numbers by 1971, with a grand
total of 43,167 Bachelor's degrees, primarily electrical engineering...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's
Matchmakers" Smith chart design. These would make excellent gifts for husbands,
wives, kids, significant others, and for handing out at company events or as rewards
for excellent service. My graphic has been ripped off by other people and used on
their products, so please be sure to purchase only official RF Cafe gear. I only
make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way
to help support RF Cafe. Thanks...
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
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