See Page 1 |
2 |
3 |
4 | of the July 2023 homepage archives. Friday the 14th
 My introduction to
servomechanisms was sometime in the early 1970s when I became aware of radio
control (R/C) systems for model airplanes, cars, and boats. Modelers referred to
them simply as servos. At the time, they were constructed with discrete electronic
components crammed onto a two-sided printed circuit board with parts mounted vertically
to save space, a brushed DC motor, and a feedback potentiometer. Cases were either
metal or plastic, and the gears were plastic. Control / power cables had four or
five wires. The servos in my first R/C system (OS Digitron 3-Channel) were 1-5/8"
x 1-3/8" x 13/16", and weighed 1.7 oz. The 4-wire cable used a center tap in the
battery to effect bias voltages for the transistor circuitry (-V/2, Neutral, and
+V/2), and the fourth wire was the pulse position control signal. Modern servos
with equivalent power are 1/8th the volume and weight, are faster, use integrated
circuits, and have a 3-wire control cable. Of course there are also larger servos,
but they are immensely more powerful...
 Is nothing sacred? Those of us 60+ people
"were there" when Pink Floyd released its "The Dark Side of the Moon" album in March of 1973 (half a century
ago). Original copies are selling for $30-$150 on
eBay. "Money" was the biggest hit on the album. "Another Brick in the Wall,"
(Hey, teacher, leave those kids alone...)from the 1979 "The Wall" album is probably their
most popular song... but I digress.
Physics World website has an article entitled "Great
gaffe in the sky: the erroneous physics behind The Dark Side of the Moon"
commemorating the 50-year anniversary by pointing out the science errors in the
album title and artwork. Note that the white light dispersing prism shown in the
article is not from the album's cover artwork, so the author's argument about refractive
indices is not referencing it (why show it, then?). "This year marks 50 years since
British rock band Pink Floyd released their seminal album The Dark Side of the Moon.
From my experience as a physics teacher, I can tell you that most teenagers today
would struggle to name a single track on the album. But a majority of them still
do recognize the iconic album cover, which depicts light refracting through a triangular
prism. Indeed, I am convinced that students will be able to name both the album
and the band if shown the artwork..."
 When this was first published, we moving
into the colder days of the year in the northern hemisphere. It was the time of
year that causes those less appreciative of cold weather to conjure up memories
of warm summer days with green leaves on tree branches and colorful flowers in the
garden. For those of you like me who actually prefer the cooler weather, this December
1960,
Carl & Jerry story about making snow by blasting clouds with ultrasonic
energy just adds to my appreciation of the onset of winter and visions of a white
Christmas. To date there has been no major, efficient progress in the field of snowmaking
or rainmaking (other than seeding clouds with silver iodide). Ski resorts still
need sub-freezing weather for their snow machines to work using a ground-based water
source (not directly from the clouds)...
 "NASA and its partners have achieved another
major milestone in the future of space communications - achieving 200 gigabits per
second (Gbps) throughput on a
space-to-ground optical link between a satellite in orbit and Earth, the highest
data rate ever achieved by optical communications technology. These data rates are
made possible by using laser communications, which packs information into the oscillations
of light waves in lasers, instead of using radio waves like most space communications
systems. This communications link was achieved by the TeraByte InfraRed Delivery
(TBIRD) system, carried into orbit by NASA's Pathfinder Technology Demonstrator
3 (PTD-3) satellite, and surpasses the previous 100 Gbps milestone previously demonstrated
by the same team in June 2022. With this speedy connection, TBIRD can send down
multiple terabytes of test data to Earth during a single six-minute pass over a
ground station. A single terabyte is the equivalent of about 500 hours of high-definition
video."
 Here is a brief synopsis on the main difference
between glass and
metal vacuum tubes - the metal case tubes generally exhibit higher interelectrode
capacitances. It showed up in a 1935 issue of Radio-Craft magazine at the
time when metal encased tubes were first appearing. Unless successfully addressed,
that limits usefulness in high frequency circuits. Of course in 1935 most radio
circuits maxed out in the tens of megahertz, so it was not too much of a problem.
One of the major advantageous features of metal tubes is the built-in EMI/RFI shielding
both for keeping desirable fields inside the tubes and keeping undesirable fields
from entering the tube...
/jobs.htm"> RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable /jobs.htm">job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 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.
Thursday the 13th
 Yeah, upon seeing the title of this puzzle,
I also thought it said "Roundworm." As is evident by the construction of the puzzle
grid, it is indeed "Roundword." Be sure when working the puzzle to spiral in toward
the center and don't do a raster scan from top to bottom. Although it appeared in
a 1960 issue of Radio-Electronics magazine, there are no terms that should give
a Millennial any problems. Careful with number 14 since today's classes of Hams
is not the same as it was back in the day...
 Werbel Microwave presents an impressive
array of features in our latest offering. The D−4047−BNC is just one of the many
coax splitter components available in our extensive range. This Werbel Microwave
power divider/splitter features a 4−way design with BNC connectors. It operates
within a frequency range of 700 MHz to 4 GHz. The D−4047−BNC is a 50 ohm
impedance power divider with a maximum input power rating of 30 watts. It has
a female input and four female output ports. This RF power splitter/divider is specifically
designed for Wilkinson applications. For detailed specifications and design information
on this coaxial BNC reactive power divider, please refer to the RF power splitter
PDF specifications datasheet provided...
 Here is the Radio Service Data Sheets for
the
Philco Model 15 Series, 11-Tube Superheterodyne Chassis, as it appeared in the
August 1932 issue of Radio−Craft magazine. As is typical of the era, a
fancy, curvaceous wooden cabinet houses the "ultra modern receiver." Philco Radio &
Television Corporation went all-out for high quality sound by incorporating two
"reproducers" - otherwise known as speakers. The partially reclined speaker surface
avoids blasting sound at kneecap level as is typical of floor console radios, preferring
rather to intercept the listeners' ears. There are still many people who restore
and service these vintage radios, and often it can be difficult or impossible to
find schematics and/or tuning information. I keep a running list of all data sheets
to facilitate a search...
 "Ampère's
theory was fundamental to electronic inventions such as motors and generators. Without
an understanding of the fundamental relationship between electricity and magnetism,
it would not have been possible to invent motors, telecommunications equipment,
kitchen appliances and more. A key part of our understanding of that relationship,
known as
classical electromagnetics or classical electrodynamics, was first theorized
in the 1820s by André-Marie Ampère, a French physicist and mathematician. Through
a series of experiments, Ampère discovered that a magnetic field is generated when
charge flows through two parallel wires, pushing them apart or pulling them together.
He also identified the important distinction between current and voltage. The unit
of electric current known as the ampere, or amp for short, is named after the founder
of electrodynamics. Ampère, a professor of mathematics at the Collège de France,
in Paris, developed a formula to measure the magnetic force between two electric
currents. It was fundamental to 19th-century developments in electricity and magnetism
by scientists including Michael Faraday...
 With a fair helping of chagrin, I admit
to being a "10-4
Good Buddy" type of Ham radio operator. That moniker is applied liberally by
pre-1991 (February 14, to be exact) amateur radio licensees to post-1991 licensees
because that was the year in which the FCC no longer required aspiring Hams to pass
a Morse code proficiency test for an entry level license (with restrictions). It
was a sort of Valentine's Day gift. In 2003, the International Telecommunications
Union (ITU) announced the rescinding of its code requirement and allowed countries
to set their own standards. By 2007, General and Extra exams no longer required
code tests. I earned my Technician license in 2010, General license in 2015, and
Amateur Extra license in 2017 - all without sending or receiving a single dit or
dah (or keying a mike for that matter). Please don't hate me for it, because I have
every intention of learning code... maybe, if I ever get to retire, which doesn't
appear likely with the cost of living rising as quickly as it is :-(
 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.
The file format is XML so everything plays nicely with Visio 2013 and later...
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
Wednesday the 12th
 The ARRL (American Radio Relay League) just
published the results of their "ARRL Member Dues Survey." Unfortunately,
access requires signing in as a member, but then most likely if you care about the
survey, you are an ARRL member and have access. 12 multiple choice questions and
one essay question polled issues was covered. Topics included are an annual dues
increase (and if yes, by how much), whether both print and digital editions should
be included at one price, if Lifetime Membership should still be offered, are you
an active Ham, would amateur radio still have dedicated spectrum if the ARRL did
not exist, from which features of ARRL membership do you benefit. I am one of the
20,077 ARRL members who responded. My essay comment about how the ARRL might trim
operational costs was to use lower quality paper and less color in the print version
of QST publication. Most issues are either never read or only read once,
and therefore highly durable (therefore more expensive) paper is not needed. It
might seem trivial, but publishing costs are high and small per-copy savings can
add up to a lot.
 "Quantum electronics promises significant
advances in ultra-sensitive measurements and quantum information processing. In
nanoelectronic circuits, one electron can be used to precisely modify the trajectory
of another electron through their mutual Coulomb interaction. This new fundamental
circuit element has now been demonstrated by three independent research teams, whose
complementary discoveries have been published in the journal Nature Nanotechnology.
Electrical current is a stream of charged elementary particles. In semiconductor
devices, ballistic electrons move at high speeds, making it difficult to address
them individually. A controlled collision of individual electrons can provide the
time resolution required for one electron to interrogate the other. The operating
principle of such an
electron collider circuit is similar to hitting one fast moving projectile with
another well-timed shot. The challenge is therefore to precisely synchronize two
individual electrons to exploit their interaction..."
 "Nuclear" this and "nuclear" that were big
attention getters after the dropping of the uranium and plutonium bombs that ended
World War II in August of 1945. Science was at the cusp of its foray into understanding
and manipulating atoms at the nuclear level - a realm that at the time was not directly
observable. "Shadows" of elementary particles were successfully imaged, but many
theorized that it would never be possible to directly "see" an electron, proton,
or neutron. One cause of the inability to image such a small entity was a lack of
a stable enough reference source that could resolve tiny features. Short wavelengths
(i.e., high frequencies) are needed, and the current standard - piezoelectric crystals
- could not be fabricated thin enough to function reliably (or at all) in the microwave
spectrum. Fulfilling the old adage of "necessity
is the mother of invention," scientists developed the first atomic clocks that
exploited a very stable and repeatable frequency reference based on electron energy
level transitions of the ammonia atom. Doing so allowed the earliest measurements
of sub-microscopic physical features of materials. This story details some of the
history...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 30 dB) and RF power dividers
/ combiners (2− to 16−way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
Tuesday the 11th
 In this second installment in his "Principles
of Modern Radar" series in Radio-Electronics magazine, author Jordan
McQuay discusses pulse-Doppler radar, which exploits the frequency shift of moving
targets to discriminate against fixed objects. The ability to separate fixed from
moving targets is generally more difficult are the moving target gets closer to
the fixed object(s), such as when near the ground during take-off and landing, and
when mountains are nearby in the background. Clutter cancellation can and is also
accomplished by comparing radar amplitude vs. time return signals to previous returns
and subtracting the two so that only the newer signal survives for display on the
scope (plan position indicator, or PPI). That is how the AN/MPN-14 (13) radar system
I worked in the in the U.S. Air Force worked...
 "Modern manufacturing is becoming more and
more complex as designers and manufacturers attempt to integrate the latest core
technologies into their solutions. Software design tools are addressing this issue
by enabling the modeling of the latest RF fin field-effect transistors (FinFET),
a complex and time-consuming process that involves massive amounts of data. An example
of such a tool is Keysight's
IC-CAP Model Generator (MG). It was recently chosen by the Samsung Foundry to
give its RF engineers the wherewithal to efficiently organize the large volumes
of data needed to develop advanced transistor models. Faster Simulation Using the
IC-CAP MG software framework, Samsung can handle data management and all of the
details involving multi-device simulations. As a result, engineers are able to focus
on creating and automating custom flows instead of getting bogged down in the process.
Accelerating Samsung's advanced RF semiconductor process technology development,
the Python-3-based MG software leverages..."
 A lot of us still use older test equipment
at home and even in the company lab. As discussed in this 1972 article from
Popular Electronics magazine, the displayed rise time on an oscilloscope display
is not necessarily that
true rise time of a signal - particularly when the speed approaches the rated
bandwidth of the equipment. In that case, it is necessary to mathematically compensate
for the rise times of each individual component used for making the measurement.
Hooking the o-scope probe tip to the calibration point on the front of the instrument
and adjusting the probe's trim capacitor for a flat response is not always good
enough. Most modern o-scopes can calculate and apply corrections automatically,
negating the need for a manual correction. If your application is not super critical
from a timing standpoint, then you do not need to bother with correction, but it
is worth keeping rise time measurement inaccuracies in mind just in case you run
into an otherwise...
 Yes, the Average Daily Sunspot Number is
certainly high, but only about half of some maximums since formal observations began
in
1749. A look at the bottom plot in the composite image I made shows that the
year before I was born (1957), the number was around 332, compared to today's 132.
The Sunspot Number
is calculated by awarding each sunspot group a value of 10, and each individual
sunspot a value of 1. For example, if there are 3 sunspot groups having, say, 2,
4, and 5 sunspots, then the Sunspot Number is 3x10 + 2 + 4 + 5 = 41. If instead
none of the sunspots were part of a group, then the Sunspot Number would be just
2 + 4 + 5 = 11. I'm sure there's a good reason for doing it that way, but why introduce
ambiguity? After a pronounced lull in the early part of Cycle 25, Ham radio
DX'ers are loving the increased solar activity because it opens up higher frequencies
for skipping off the ionosphere. Of course during heavy sunspot activity the probability
of a major
coronal
mass ejection (CME) directed toward Earth is much greater than normal, and that
could significantly interrupt communications and power distribution systems. Anyway,
when you see headlines and news distorters [sic] hyperventilating about the sun's
activity, don't go stocking up on food, medical supplies, and ammo in the backyard
bunker -- at least not yet.
 You will be excused for not knowing that
Norelco, famous today (or was it seemingly just yesterday?) for its line of
electric shavers, coffee makers, and cassette recorders, once was famous for its
radio loudspeakers. Norelco also offered a line of wooden speaker cabinets. This
advertisement appeared in the April 1957 issue of Radio and TV News magazine.
"Sink me, the copy writer's a poet," to shamelessly paraphrase Sir Percy Blakeney
from "The Scarlet Pimpernel..."
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 2018 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. An intro video takes you through the main features...
 Aegis Power Systems is a leading supplier
of AC-DC and
DC-DC power supplies for custom and special applications. Aegis has been designing
and building highly reliable custom power supplies since 1995. They offer a complete
line of switch mode power supplies and power converters for a variety of markets
including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft,
EV, telecom, and embedded computing applications. Design and manufacture of custom
power supply solutions to meet each customer's exacting specifications. Please visit
Aegis Power Systems today. Manufactured in the USA.
Monday the 10th
 Here is the follow-up article from Phillip H.
Smith's original "Transmission Line Calculator" of his Smith Chart in the January
1939 issue of Electronics magazine. "An
Improved Transmission Line Calculator" appeared in the January 1944 issue. Mr. Smith
worked at the Radio Development Department of Bell Telephone Laboratories in New
York City. He states in part, "The calculator is, fundamentally, a special kind
of impedance coordinate system, mechanically arranged with respect to a set of movable
scales to portray the relationship of impedance at any point along a uniform open
wire or coaxial transmission line to the impedance at any other point and to the
several other electrical parameters. These other parameters are plotted as scales
along the radial arm and around the rim of the calculator, both of which are arranged
to be independently adjustable with respect to the main impedance coordinates."
A thorough discussion of the Smith chart's constructions and examples of its use
are presented...
 Anatech Electronics offers the industry's
largest portfolio of
high-performance standard and customized RF and microwave filters and filter-related
products for military, commercial, aerospace and defense, and industrial applications
up to 40 GHz. Three new filters have been announced: a 3-7 MHz bandstop/notch
filter with BNC female connectors, an 8 MHz LC highpass filter with BNC connectors,
and a 14.7 MHz bandpass filter with N-type connectors and a bandwidth of 2.0 MHz.
Custom RF power filter and directional couplers designs can be designed and produced
with required connector types when a standard cannot be found, or the requirements
are such that a custom approach is necessary...
 Test your knowledge of the country of origin
of the inventors responsible for these ten inventions by taking this "International
Electronics Quiz." It appeared in the July 1967 issue of Popular Electronics
magazine. In some cases the inventor was born in another country but then emigrated
to the U.S. or another country before his/her invention or discovery. This is a
pretty tough quiz even for someone who has done a lot of reading on the history
of technology. Guessing the country of origin for the inventor of the voltaic pile
might be easier if you recall the guy's name (hint: his name is in the caption),
and for the TV antenna take note of the configuration of the elements (hint: there
was nobody named Log Periodic). I'm too embarrassed to divulge my score, but if
you do better 50% or better, you've beaten me...
 "Photos
from low-earth orbit (LEO) are often strikingly beautiful. But what they typically
fail to capture is the tens of thousands of debris pieces, or 'space junk,' that orbit
around Earth's face like hungry mosquitos - and threaten to hit satellites and other
orbiting assets with enough force to be destructive. Such pieces of space junk -
only a fraction of which space agencies like NASA and ESA can track with ground-based
telescopes - are only going to multiply as mega-constellations like Starlink or
OneWeb enter LEO. A growing number of planners and researchers are concerned about
whether further crowding could lead to a higher risk of catastrophic collisions
that knock out communications satellites or even one day send fiery debris back
home to Earth. To better anticipate and avoid these situations, some are turning
to computer simulations and artificial intelligence to better see what humans cannot..."
 My Uncle Brian was a
radioman in the U.S. Navy during the end of the Korean War era. A great story
teller, he used to talk about his Navy experiences and later times as a United Parcel
Service (UPS) tandem semi trailer driver when he and others from my Buffalo side
of the family would come to visit during summers when I was a kid. He spent most
of his enlistment on a gravy assignment at the U.S. embassy in Australia, relaying
messages between self-important bureaucrats at the Pentagon and self-important bureaucrats
at the U.S. embassy in the Down Under. His favorite saying about his time in the
service was, "I joined the Navy to see the world, and all I saw was the sea." I
laugh every time I hear it...
 Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 website visits
each weekday.
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Your 728x90-px and 160x600-px Banner Ads are displayed
on average 225,000 times per year! New content is added on a daily basis,
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each day. Items added on the homepage often can be found in a Google search within
a few hours of being posted. If you need your company news to be seen, RF Cafe is the place to be...
 Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
Sunday the 9th
 This custom RF Cafe
electronics-themed crossword puzzle for July 9th contains words and clues which
pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. Being that "I" is the 9th letter of the alphabet, it is used as the first
and/or last letter of many words in today's crossword puzzle - as well as in-between.
Those clues are marked with an asterisk (*). As always, you will find no references
to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles?
A list at the bottom of the page links to hundreds of them dating back to the year
2000. Enjoy.
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
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.
About RF Cafe.
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