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4 of the July 2021 homepage archives. Wednesday the 7th
 In 1944 when this National Union Radio Company
ad appeared in Radio News magazine, the price of gold bullion was $35 US
per ounce, as established by the Bretton-Woods Agreement. Inflation remained near
zero until 1971 when President Nixon removed the U.S. treasury notes (dollars) from
the gold standard. Take a look at the inflation chart in the background of the RF
Cafe header (top of page) to see what has happened since then. Today's spot gold
bullion price is around $1800 per ounce - a factor of 51x higher. According to the
Bureau of Labor Statistics' Inflation Calculator, $35 in 1944 had the equivalent
purchasing power of $538 today - a factor of 15x. That means the inflation-adjusted
price of gold is about 3x what it was when National Union decided to use it to
plate the wire control grid of its high power vacuum tubes in order to minimize
performance-degrading grid emissions. Because relatively little gold would have
been used...
 Last week Melanie and I drove down to Greensboro,
North Carolina, to attend our daughter's wedding. The weather was typically hot
there, but not out of the norm. All went well at the small ceremony. Both bride
and groom showed up, as did the minister and necessary witnesses. After the blessed
event was over, we headed back northward to our humble abode in Erie, Pennsylvania.
Our route upon exiting NC is I81 for a few miles in Virginia, then north onto I77,
up to Rt. 19, then I79 all the way home up and down mountains for a few hundred
miles. Our 2011 Jeep Patriot has never had any mechanical issues, but then it only
has 81k miles on it and is kept in the garage. That day, though, the transmission
overheating idiot light illuminated while on I81 - not a particularly hilly stretch.
The outside temperature there was about 80 °F. I had noticed a slightly higher
pitch sound from it while going uphill, but didn't think anything of it until the
light came on. (On-Trak
Automotive Services)...
 "Humans have effectively created continent-size
antennae - all exquisitely tuned to soak up currents caused by space weather" -
John Kappenman of Storm Analysis Consultants, re the vulnerability of our massively
networked electrical supply grids. He was quoted thus in the July 2012 edition of
Popular Mechanics in an article entitled "Welcome to the Next Solar Maximum."
Activities on our sun can effect profound consequences here on Earth, both in the
form of communications disruptions and in the form of electrical supply grid disruptions.
Both can be dire with the potential of crippling worldwide commerce. News agencies
often refer to the violent spewing of copious quantities of high-speed electrons,
protons, and neutrons as sunspot activity, but in fact, the phenomenon is termed
coronal mass ejection (CME). Billion-ton belches of sun guts can be sent hurling
earthward. Fortunately for us, not all CMEs are directed toward Earth, but enough
do that NASA and the DoD...
 Axiom Test Equipment, an electronic test
equipment rentals and sales company headquartered in North County San Diego, currently
has the need for an
Electronic Test Equipment Calibration Technician. We are looking for an experienced,
dedicated and ethical electronic calibration technician to help support our team.
Do you want to work in a low-stress calibration lab, Monday through Friday, with
no on-sites? Would you prefer to be treated as a person and not a number? If you
have experience calibrating RF/Microwave, GPTE, and high-power test equipment, come
talk to us about joining our team in Vista California. General Description: To calibrate
both customer-owned and Axiom-owned electronic test equipment by performing one
or more of the following: calibration, installation of options, troubleshooting,
refurbishing, maintenance of electronic test and measurement equipment. Assist salespeople,
customers...
 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 object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Stencils 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...
 Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
Tuesday the 6th
 "Those who cannot remember the past are condemned
to repeat it." That line from George Santayana's The Life of Reason: Reason in Common
Sense always comes to mind whenever I see articles from vintage publications about
how people at the time were being forced to defend their ways of life from maniacal
would-be dictators who marshaled armies of like-minded crazies to invade and attempt
to subdue other countries and/or citizens within their own borders. It seems after
a generation or two of comfortable, relatively safe existence, the collective guard
is lowered and the hard-lessons from history are forgotten or subversively erased
from memories. This particular 1944 Radio News magazine article tells the
story of women of European Allied nations - in particular Polish women - taking
up arms against Axis powers (Germany and Italy) during World War II. Part of
the survival effort included learning to
operate and service communications equipment in order to provide surveillance
and security both on the battlefield and in helping countrymen escape the incursion.
Some were captured...
 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.
 "With
booms spreading almost the length of a football field, the Air Force Research
Laboratory's Demonstration and Science Experiments spacecraft is the largest self-supporting
satellite ever placed on orbit. Last month, nearly two years after it launched and
a year after its mission was expected to end, AFRL decommissioned the satellite.
Although the DSX satellite launched in 2019, work on the experiment actually began
in 2003. AFRL wanted to conduct research on the harsh radiation environment of medium
Earth orbit, defined as the massive space between 1,243 miles and 22,236 miles above
sea level. Emissions from the Van Allen radiation belts in MEO are particularly
challenging and can damage satellites..."
 This vintage
Heathkit HW-8
QRP Transceiver kit is one of the latest unbuilt Heathkit kits which appeared
today on eBay - a fitting subject for the "Why Key Clicks?" article below.. I have
been saving the images in order to preserve the history. The constantly growing
list is at the lower right. The HW-8 covers the 80-, 40-, 20-, and 15-meter bands
for CW. As you can see from the video at the bottom of the page, there were a lot
of parts in the kit to assemble. The first instance I could find for HW-8 being
offered for sale was in the Spring 1976 Heathkit catalog (p79), at a cost of $129.95
($623.56 in 2021 money per the BLS). From the Spring 1976 Heathkit catalog: "We've
made the world's most popular low-power CW transceiver even better! To the Heathkit
HW-7 - we have added more bands, more features and a super new receiver section
that's the best in its class. The famous HW-7 QRP Transceiver helped thousands of
hams work the world on a couple of watts - and on a budget. Now, in the same value
conscious tradition, Heath announces the HW-8...
 Waveform shaping is essential in today's
crowded communications spectrum. Spectral masks are precisely defined in order to
prevent "spreading" beyond the allocated frequency ranges at defined power levels.
Whenever anything other than a continuous sinewave is being broadcast, there is
spectral content generated in addition to the fundamental frequency. A Fourier transform
of the waveform reveals which frequencies at what power levels comprise the waveform.
The CW signal used by Morse code operators is a pure sinewave (or nearly so), but
there is a spectral problem with it every time the signal turns on or off because
of the square-ish edges involved during switching. RC networks are used in the transmitter
circuits to tame the edges so that they do not turn on and off so quickly and in
doing so reduce the extraneous frequency content. Author George Grammer argues that
even though the signal could theoretically be made "clickless" (aka "chirpless"),
there is an auditory benefit to the clicks or chirps that aids operators listening
to high speed code transmissions...
 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...
 TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between -100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Monday the 5th
 This is Part 13 of a series entitled
"The
Saga of the Vacuum Tube," by Gerald Tyne, that appeared in Radio News magazine
in 1944. Part 1 was printed in March 1943, and Part 22, the final chapter,
was published in April 1946. It could have been a stand-alone book. If I manage
to be able to buy issues with some of the other parts, those will be posted as well.
You might be aware of the origins of the amplifying vacuum tubes, beginning with
the accomplishments of Dr. de Forest and his Audion. As with most new technologies,
progress moved very rapidly once other researchers glommed on to the concept. Here,
Mr. Tyne discusses the development of the "Kenotron," "Pliotron," "Dynatron,"
and "Magnetron," by Drs. Langmuir, Dushman and Hull of the General Electric
Laboratories, during the years 1913 to 1921...
 This JavaScript calculator converts between
noise figure and the equivalent noise temperature. Just what is noise temperature
and why is it used? Simply put, noise temperature is the temperature at which a
resistor at the component / system input would generate the same amount of noise
measured at the output. It goes back to the familiar kTB calculation for thermal
noise power. Noise temperature is often used in calculating the overall noise figure
of a system that includes an antenna at the input. That is because strictly speaking,
a 1-port device like an antenna cannot be defined in terms of noise figure...
 Axiom Test Equipment, an electronic test
equipment rental and sales company, has published a new blog post entitled "Spectrum
Analyzers Check 5G Occupied Bandwidth" that informs people on how the right
spectrum analyzers can help locate the interference of additional signal energy
that can interfere with 5G service. With a suitable spectrum analyzer, occupied
bandwidth measurements reveal the total integrated all signal energy within the
bandwidths that concern 5G system designers, service providers, and users and when
any interfering signals are at high enough power levels to be a concern. Selecting
a spectrum analyzer for occupied bandwidth testing is a matter of matching the equipment's
capabilities to the limits of the OBW measurements. An analyzer's frequency range
and amplitude range are good starting points for 5G OBW measurements...
 "Backscatter
radios encode data in reflected signals to offer wireless communications that
consume as little energy as possible - but they can be limited by poor data rates.
Now scientists at Nokia Bell Labs and their colleagues have developed backscatter
radios capable of gigabit speeds, for potential use in the emerging Internet of
Things and other devices, a new study finds. Whereas conventional radios generate
their own signals, backscatter radios transmit data by making tiny changes to reflected
signals. This approach requires a minimal number of active components, promising
simple low-cost battery-free operations. However, the low frequencies that backscatter
radios often employ and the strategies they use to encode data in reflected signals
typically limit their data rates..."
 Wirewound inductors (as most are) can be
mysterious entities even when you are familiar with their many interdependent physical
and electrical properties. Because of interwinding capacitance and a sometimes (when
a large number of turns are involved) rather significant series resistance, the
equivalent circuit model gets quite complex - literally in a mathematical sense.
If you have the luxury of staying far away from the
self-resonant frequency (SRF) of the coil, your component will behave very much
like an ideal inductor, that is, XL = 2πfL. This 1966
Electronics World magazine article delves into what causes inductors to
act like parallel and/or series resonant tank circuits, how to avoid the inconvenience
of unwanted resonances, and how to exploit resonances in your favor. You'll also
learn (if you don't already know) the distinction between a "choke" and an inductor...
 Innovative Power Products (IPP) has over
30 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Please take a couple minutes
to visit their website and see how IPP can help you today.
Sunday the 4th
 ...because
it is important to remember what is actually in it - not just what the Public Schools
teach about it::: "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..."
 This
Radio
Theme Crossword Puzzle for July 4th has a few words paying homage to what remains
of the freedoms and promises of America, along with words and clues related to RF,
microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and
other technical subjects. 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., Reginald Denny or
the Tunguska event in Siberia). The technically inclined cruciverbalists amongst
us will appreciate the effort. Enjoy!
Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets
exceedingly high standards of quality, performance and excellent value, and are
100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz.
Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production.
All products are custom designed. We will find a solution and save your time and
cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Friday the 2nd
 The Dog Days of Summer run from July 3rd
through August 11th. In fact, they begin tomorrow (as of when this is being written).
John Frye usually wrote his monthly Mac's Radio Service Shop technodramas to correspond
with the month - at least the season - in which it was published, so "Dog
Day Discussions" is aptly placed in the August 1952 issue of Radio &
Television News magazine. This episode dealt with how some TV manufacturers
were dealing with the relatively new technology as the sets were being ravenously
consumed by householders. Owners in fringe areas with weak signals or signals experiencing
a lot of multipath interference were registering complaints about their very expensive
television delivering poor performance. One response was to issue retrofit kits
to service shops for peaking reception sensitivity while filtering out nearby out-of-band
noise. In those days you didn't simply throw out your old TV or radio and buy a
new one. An interesting phrase...
 Atomically thin materials are a promising
alternative to silicon-based transistors; now researchers can connect them more
efficiently to other chip elements. Moore's Law, the famous prediction that the
number of transistors that can be packed onto a microchip will double every couple
of years, has been bumping into basic physical limits. These limits could bring
decades of progress to a halt - unless new approaches are found. One new direction
being explored is the use of atomically thin materials instead of silicon as the
basis for new transistors but connecting those '2D' materials to other conventional
electronic components has proved difficult..."
 Exodus Advanced Communications, a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide, introduces the
AMP2053A-1. Model AMP2053A-1 is a rugged solid state power amplifier (SSPA)
replacing aging TWT technology. It is a broadband class A/AB amplifier design for
all industry standards, with a wide 6.0-10.0 GHz bandwidth, a minimum power
output of 100 W Minimum (>120 W typical) and 50 dB of gain. The
SSPA features excellent power and gain flatness as compared to TWT's. Forward and
reflected power monitoring, VSWR, voltage/current and temperature sensing are provided
for superb reliability and ruggedness. The nominal weight is 45 lbs. in a compact
4U chassis, 7"H x 19"W x 22"D...
 Here is another instance that shows how much
expectations have changed over the years. Except maybe for an experimenter or someone
set on reproducing original equipment as closely as possible, nobody would even
consider trying to build capacitors from scratch. Compared to when this "Roll
Your Own Capacitors" story appeared in a 1956 issue of Popular Electronics
magazine, components nowadays are so inexpensive that it's just not worth the trouble.
If you are one of the extreme do-it-yourself type people, then this story is for
you. Come to think of it, another use for this article is to provide material for
a physics class laboratory exercise where the student calculates a predicted value
for capacitance based on surface area, dielectric constant, and plate separation
distance...
 The
Dog Days of Summer, contrary to what many people believe, is named
not to describe the hottest, most humid, most oppressive period of the year, but
marks the astronomical point in time following the heliacal rising of the star system
Sirius, aka the
Dog Star in the constellation
Canis Major.
40 days later, on August 11th, the Dog Days end. That also happens to be middle
of summer (not midsummer),
which is on or about August 6th. Never having been a proponent of summer, the end
of the Dog Days has always meant we're closer to the end of summer than to the beginning,
and autumn is on the way.
 RF Cascade Workbook 2018 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...
 Since 2003, Bittele Electronics has consistently
provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly
services. It specializes in board level turnkey
PCB assembly
for design engineers needing low volume or prototype multi-layer printed circuit
boards. Free Passive Components: Bittele
Electronics is taking one further step in its commitment of offering the best service
to clients of its PCB assembly business. Bittele is now offering common passive
components to its clients FREE of Charge.
Thursday the 1st
 Many people in the electronics realm - both
producers and consumers - were reluctant to let go of their dearly beloved vacuum
tubes and adopt the newfangled semiconductor components. To be honest, I likely
would have been one of them based on my aversion to change. In 1958 when this "Tiny
Tube Steals Transistor's Thunder" feature graced the cover of the August issue
of Radio-Electronics magazine, the transistor was barely a decade old and
could not yet operate at high temperatures, high frequencies, high voltages, or
under rugged mechanical conditions. This particular miniature tube was the creation
of GE, and soon thereafter RCA introduced their "nuvistor" to compete with transistors.
History shows, of course, that the battle was handily won by the semiconductor industry,
and we're better off because of it. Still, there's something about the soft orange
glow of a vacuum tube in a darkened room that sets a mellow mood...
 ""The 2018 Nobel Prize in Physics was shared
by researchers who pioneered a technique to create ultrashort, yet extremely high-energy
laser pulses at the University of Rochester. Now researchers at the University's
Institute of Optics have produced those same high-powered pulses - known as
chirped pulses - in a way that works even with relatively low-quality, inexpensive
equipment. The new work could pave the way for better high-capacity telecommunication
systems, improved astrophysical calibrations used to find exoplanets, more accurate
atomic clocks, precise devices for measuring chemical..."
 I and others joke frequently about the promise
of flying cars, automated homes, and miracle pills to cure any maladies that were
predicted to be commonly available by the end of the 20th century. Magazines like
Popular Science, Mechanix Illustrated, Science and Mechanics,
et al, regularly printed stories about these and a host of other inventions that
were just around the corner. Most have never been realized, but we're appreciative
of the dreamers and those people who dedicated their lives - often to the point
of financial and/or physical ruin - while trying to succeed. Taking a different
approach, Edwin Lawrence, in this 1956 article in Popular Electronics,
solicits readers to consider inventing a few 'needed
inventions" that he throws out. Among them death ray that will incapacitate
or kill at great distances, a speech-into-writing translator, a buried explosive
detector, a 3-dimensional visual display, a device for recording television programs,
and a handful of other ideas. Interested parties are bade to contact the National
Inventor's Council...
 This
is a Javascript
calculator for
fixed Pi and T attenuators. Enter values for Rin, Rout, and Attenuation, then
click Calculate. If unequal termination resistances are used and an attenuation
value is selected that is lower than what is physically possible (a negative resistor
value is displayed), then a message will appear in the box over the schematics.
"k" is the linear ratio equivalent to the decibel value of the attenuator. Equations
used in this calculator can be found on the Pi and Tee Attenuators Equations page...
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 object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Stencils 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...
 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. 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.
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. I also
have an extensive list of
Recently Added topics.
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