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 A lot of RF Cafe visitors might not be familiar
with some of the electronic waveforms presented in this
Oscilloscope Quiz by Popular Electronics magazine's ultimate quizmaster, Robert
Balin. The shapes are recognizable to anyone who has done a lot of design, troubleshooting,
testing, or alignments on analog circuits. Electronics repairmen were intimately
familiar with these - and much more complex - waveforms. Modulation of the z-axis
is especially cool as it varies the intensity of the waveform. I always roll my
eyes when, back in the day, a laboratory or medical facility in movies or on TV
had an oscilloscope display with a Lissajous pattern writhing on the display...
 "SpaceX is putting its longstanding focus
of sending humans to Mars on the backburner to prioritize
establishing a settlement on the Moon, founder Elon Musk said Sunday. The South
Africa-born billionaire's space company has found massive success as a NASA contractor,
but critics have for years panned Musk's Mars colonization plans as overambitious.
The move also puts Musk in alignment with U.S. President Trump's shift away from
Mars. "For those unaware, SpaceX has already shifted focus to building a self-growing
city on the Moon, as we can potentially achieve that in less than 10 years, whereas
Mars would take 20+ years. Difficulties in reaching Mars include the fact that "it
is only possible to travel to Mars when the planets align every 26 months..."
 Life for the blind has always been fraught
with obstacles that we who can see will never be able to fully appreciate. Society
has come a long way in accommodating the special needs of those with no or severely
reduced eyesight. Recent news stories report of experiments with electronic implants
that use implants set into the eye and couple somehow with the retina to send image
information to the person's brain. While in no way close to being able to be called
sight, it has at least allowed the guy or girl with training to detect and avoid
obstacles based on changes in scenery shading. We are probably a century away from
true bionic vision, incremental improvements will thankfully improve
the lives of our thusly challenged brethren. This article from a 1947 edition of
Radio News reports on efforts made by the New York Institute for the Educations
of the Blind to make amateur radio...
 everythingRF, a long-time supporter of this
website, is now, in addition to publishing e-books, putting out an
e-zine which provides
some insightful content, interesting products and expert interviews within the RF &
Microwave industry. Vol. 4, now available, includes articles on Next Gen Adjustable
Q-Band Gain Equalizers, Earth to Orbit:The Important Role of Antennas in NTN, Benefits
for Phased Array Systems Through SM Components, as well as product features, upcoming
industry events, and more.
Download it now.
 Have you ever heard of a
"globar" resistor? They have been around since the early days
of radio and were used, among other things, to protect vacuum tube heater elements
from burning up due to high inrush current when first turned on. Globars have a
negative temperature coefficient (NTC) of resistance so that, opposite of standard
carbon and metal film type resistors, they exhibit a higher resistance when cold
than when hot. Mac and Barney discuss their use in this episode of "Mac's Radio
Service Shop." You might be more familiar with the name "thermistor" for such devices,
but globars are unique elements in that their construction from non-inductive ceramic
material makes them useful at high power levels and high frequencies. Globar appears
to now be owned by Kanthal (aka Kanthal Globar). Interestingly, Keysight Technologies...
 Louis Garner was the semiconductor guru
for Popular Electronics magazine in the 1960s when he wrote this article
attempting to
demystify the proliferation of over 2,000 transistor types. He devised a "transistor
tree," tracing evolution from the obsolete point-contact transistor - unstable with
high gain but noisy - to advanced designs balancing cost, frequency, power, and
reliability. It covers pnp and npn basics, then details processes: grown-junction
(inexpensive, good high-frequency); meltback diffused (similar, better response);
alloyed-junction (popular for power); surface-barrier family (SB, SBDT, MA, MADT;
excellent high-frequency, low voltage); post-alloy-diffused...
 "Gentlemen,
ei*π
+ 1 = 0 is surely true, it is absolutely paradoxical; we cannot understand
it, and we don't know what it means. But we have proved it, and therefore we know
it must be truth." - Benjamin Peirce
(not to be confused with Captain Benjamin Franklin "Hawkeye" Pierce), 19th century Harvard mathematician.
ei*π
+ 1 = 0 i, BTW, is known as
Euler's identity
- engineers live by it.
 "Scientists have shown that
twisting a crystal at the nanoscale can turn it into a tiny, reversible diode,
hinting at a new era of shape-engineered electronics. Researchers at the RIKEN Center
for Emergent Matter Science, working with collaborators, have created a new technique
for building three-dimensional nanoscale devices directly from single crystals.
The approach uses a focused ion beam instrument to precisely carve materials at
extremely small scales. Using this method, the team shaped tiny helical structures
from a topological magnetic material made of cobalt, tin, and sulfur, known by its
chemical formula Co3Sn2S2..."
 I am constantly amazed when reading stories
about how easily Adolph Hitler rose to power in Germany by encouraging and exploiting
resentment of his countrymen over being forced, among other concessions outlined
in the Treaty of Versailles, to disarm militarily and make reparations for atrocities
committed in World War I. Part of the Nazi (National Socialist) party success
was extensive use of propaganda via print, radio, and the relatively new technology
of television. Government exercised complete control over the mainstream media (i.e.,
not "underground") by dictating content that promoted the proclaimed virtues of
Nazism and the Aryan race and the vices of just about every other form of government
and race. At the height of Hitler's reign of terror during the Third Reich era,
radio and television sets were only permitted to use crystals
tuned to state-sponsored...
 Manmade electrical noise (QRM) and natural
electrical noise (QRN) has been the nemesis of communications
- both wired and wireless - since the first signals were sent. While it is true
that over the last century the amount of "background" noise has increased significantly,
the ability of modern circuits to deal with (reject) it and/or accommodate (error
correction) it has pretty much kept up with the advancement. You might be tempted
to think that "back in the good old days" such problems did not exist, but operators
were plagued by poorly designed and inadequately filtered transmitters as well as
really deficient electrical service installation that spewed noise from transformers,
inadequately grounded transmission lines, lousy connections...
 Please take a few moments to visit the
everythingRF website to see how they can assist you with your
project. everythingRF is a product discovery platform for RF and microwave products
and services. They currently have 354,801 products from more than 2478 companies
across 485 categories in their database and enable engineers to search for them
using their customized parametric search tool. Amplifiers, test equipment, power
couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
 The debate about upgrading electronics service
shop equipment
from vacuum tube to solid-state instruments was raging in the late 1960s, when
this Mac's Service Shop story appeared in Electronics World magazine. Barney
is querying Mac regarding FET-based VOM performance specifications he is considering
to replace a VTVM. He covets the Hewlett-Packard 217A square-wave generator, delivering
clean 1 Hz-10 MHz waves with 5-ns rise time and scope triggering, justifying its
$300-$400 cost for precise scope testing. An electronic counter for 5 Hz-10 MHz
frequencies, with four- or six-digit readouts and line- or crystal-gated accuracy..
 A lot of people like to demean engineers
and scientists for their propensity to want to
conduct experiments and obtain measured, empirical data rather
than "winging it" and being satisfied with "intuitive" knowledge or the contemporarily
popular term "gut." If mankind had not adopted scientific methods and ventured beyond
the "cradle of civilization" on the African continent, we would all still be living
in grass huts, hurling rocks at prey, making clicking sounds for communication,
and foraging for berries. Quantifying and categorizing all things in nature helps
inventors create new and improved implements that help make life better. Early on
it was mostly individuals like Archimedes, Euler, Newton, and Edison who built the
pool of knowledge that fed and evolved into corporations, governments, and universities
doing the vast majority of the work. Bell Laboratories...
 "A new metasurface lets scientists flip
between ultra-stable light vortices, paving the way for tougher, smarter wireless
communication. Scientists have developed a new optical device capable of producing
two different types of vortex-shaped light patterns: electric and magnetic. These
unusual light structures, called
skyrmions, are known for their exceptional stability and resistance to interference.
Because they hold their shape so reliably, they are strong candidates for carrying
information in future wireless communication systems. 'Our device not only generates
more than one vortex pattern in free-space-propagating..."
 You can buy a pretty good metal detector
today for a hundred dollars that will find coins buried many inches deep and larger
metallic items even deeper, and you even get discriminator functions to filter out
unwanted objects like tin cans. They weigh just a couple pounds and can be used
with one arm. Compare that to early
metal detectors that had huge induction coils on a frame so heavy
that shoulder straps were needed just to lug them around. Some models came on wheels
for pushing or pulling like a cart. You could plan to spend a few hundred dollars
(a thousand or more in today's dollars) for one. Even then, they were not as sophisticated
as the $50 models sold in Walmart now. In classic fashion, teen electronics hobbyists
Carl and Jerry use their technical prowess to design and build their own metal detector
and then unintentionally using it to convince...
 This might be one of the earliest printed
instances of Harold A. Wheeler's simplified formulas for the
three basic inductor forms. Wheeler is credited with having devised the first
automatic volume control (AVC) using diode envelope detection. We all use them on
a regular basis, but for most the origin was never known or has long since been
forgotten (I fall into the latter category). I did some research on Wheeler's
inductance formulas a few months ago while working on what is now titled "RF Cafe
Espresso Engineering Workbook™," so it was sort of déjà vu when this blurb appeared
in a 1932 edition of Radio-Craft magazine...
 The leading website for the PCB industry.
PCB Directory is the largest directory of
Printed Circuit Board (PCB)
Manufacturers, Assembly houses, and Design Services on the Internet. We have listed
the leading printed circuit board manufacturers around the world and made them searchable
by their capabilities - Number of laminates used, Board thicknesses supported, Number
of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
 Don't let the title fool you. This "Ultrafax" system developed by RCA in the late 1940s was essentially
the first attempt at video on demand, or streaming video. Rather than piping the
signal over cable or local broadcast frequency towers, a microwave link was used.
While initial system equipment space and financial requirements meant only corporations,
universities, and governments could procure an Ultrafax, engineers who developed
the system envisioned an eventual culmination of equivalent systems in every home.
Even at the end of the last century it was still not possible for program providers
to personalize broadcasts to individuals. It wasn't until broadband Internet came
on the scene in the 2000s that such services were possible. Now, a decade later,
people watch any video they want on cellphones while riding in a car...
 Maxwell's inception of the theory of electromagnetic
radiation is compared here 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...
 "A research team affiliated with UNIST has
introduced a novel, high-performance, and thermally stable polymer-based non-volatile
analog switch. This next-generation device is as
thin and flexible as vinyl, yet capable of withstanding high temperatures. Professor
Myungsoo Kim and his team from the Department of Electrical Engineering at UNIST,
in collaboration with Professor Minju Kim from Dankook University, have developed
this robust, flexible radio-frequency (RF) switch. Such technology could enable
reliable 5G and 6G wireless communication in demanding environments -- such as wearable
devices and the Internet of Things (IoT)..."
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes. Our
WM4PD-0.5-18-S is a wideband 4-way in-line power splitter covering 500 MHz
to 18 GHz with excellent return loss, low insertion loss, and high isolation
performance. The device covers several military radios letter octave bands in one
product, delivering much value to the program. Aluminum enclosure measures 6.25
x 2.98 x 0.50", includes four through-mounting holes, and has durable, stainless
steel SMA female connectors. One device covers the upper UHF band, as well as L,
S, C, X and Ku bands...
 This week's
Wireless Engineering crossword puzzle contains the usual collection
of only 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!
 Providing full solution service is our motto,
not just selling goods. RF &
Connector Technology has persistently pursued a management policy stressing
quality assurance system and technological advancement. From your very first contact,
you will be supported by competent RF specialists; all of them have several years
of field experience in this industry allowing them to suggest a fundamental solution
and troubleshooting approach. Coaxial RF connectors, cable assemblies, antennas,
terminations, attenuators, couplers, dividers, and more. Practically, we put priority
on process inspection at each step of workflow as well as during final inspection
in order to actualize "Zero Defects."
 "Essayons," that's the motto of the U.S.
Army Corps of Engineers. It means "Let us try," in French. In 1968, when this
G.I. Engineers editorial appeared in Electronics World magazine, it
noted that about 38,000 engineers, or roughly roughly 6% of the nation's total,
served in the U.S. Armed Forces, far more technically skilled than in World War
II or Korea. Despite surpluses in bachelor's-degree holders, advanced-degree shortages
persisted, with over 15 thousand master's and PhD positions unfilled - by fewer
than 8,500 qualified personnel, forcing underqualified assignments. Utilization
varied: Air Force effectively deployed 14,000 engineers in R&D and civil roles;
Navy specialist programs covered ship, ordnance, aeronautical, and Civil Engineer
Corps (Seabees)...
 Here is a handy-dandy baker's dozen worth
of "kinks," otherwise known as
tricks, shortcuts, or clever ideas, that could prove useful while
working in the lab at work or in your shop at home. One suggestion is to place a
sheet of tracing paper over your schematic while wiring a circuit and draw each
connection as it is completed, rather than mark up the original drawing. That was
definitely good for a time when making a spare copy of a magazine page or assembly
instruction from a kit was not as simple a matter as it is today...
 "Apple has published a patent application
describing a method to detect user gestures on wireless earbuds by measuring changes
in RF antenna impedance, potentially reducing the need for dedicated touch-sensing
hardware. The filing, titled 'Gesture
Detection Based on Antenna Impedance Measurements,' published on January 8,
2026 as US 20260010234, describes using antennas already present for wireless communication
as dual-purpose components that can also detect user input..."
|
 • FCC to
Exempt Amateurs from Foreign Adversary Reporting
• Continuing
Your Professional Education in 2026
• India Reaches
400M 5G Subscribers
in 3 Years
• EIB Backs
Europe's 1st Gallium Production Investment
• 2026 a
Pivotal Year for 6G Standardization
• New
60-Meter Frequencies for Hams
 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.
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...
 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...
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...
 "One of the least orderly and most poorly executed
of NASA projects," was the description given to the
Surveyor program whose goal was to land on the moon and send back images,
both still and motion (in preparation for a manned landing). That, from a
congressional sub-committee. Yes, the very same Congress that famously cannot
balance its own budget or create successful programs of its own. It is a classic
case of "The pot calling the kettle black." NASA was and always has been at the
bleeding edge of new technology and as such lives in uncharted territory.
Unexpected pitfalls lurk everywhere - a minefield of "gotchas." Not that every
organization can't benefit from external oversight to prevent "blinders-on"
engineering and management teams from straying too far off the defined path, but
having the notoriously pompous and buffoonish bureaucrats...
 Before the Internet, cellphone apps, and
personal computers, many calculations began with a lookup table, chart, or nomograph.
In the case of long distance radio operators [Ham, Short Wave Listener (SWL), and
professional types] seeking distance and direction information for pointing antennas,
it took a map like this one published by Radio News & Short-Wave magazine
in 1934 to estimate an optimal configuration. Such tools were essential in order
to determine the best direction to point the antenna, which over a long distance
is usually much different than what might be assumed by looking at a
flattened projection map of the earth (see "Distance Lends Enchantment"
below). Distances in Chart No. 1 are all relative to New York, so operators
in other locales need to compensate. Here is one example of many online great circle
calculators...
 When I think back at the
engineering labs
from my days in school, I wonder how much things have really changed from then until
now. It is hard to believe that freshman and sophomore labs are not still consumed
with radial lead resistors, inductors, and capacitors, solderless breadboards, and
a variety of light bulbs, motors, transformers, relays, and rheostats. By the time
you move into the junior year, labs have gotten a bit more intense with microprocessor
controls (mine used an 8088 CPU with machine language programming for the serial
port), some high voltage apparati[sic], digital logic circuits, and a chance to
lay out/fabricate/populate a PCB. On-hand test equipment consists of 2nd or 3rd
generation oscilloscopes, signal generators, and power supplies. I did a search
for photos of labs from back in the early to mid 1900s to see if much had changed
from then until the time I was in college...
 Here is a sample of what passed as big news
in the electronics world in 1965 as reported in none other than Electronics
World magazine. Linear integrated circuits were beginning to be designed into
commercial products and a lot of effort and money was invested in promoting the
newfangled technology to the public. Prices were rapidly falling as acceptance increased.
The truth is the vast majority of the general public had no idea what the
difference was between vacuum tube and semiconductor equipped radios, televisions,
phonographs, tape recorders, etc., from a performance standpoint. What they did
notice was the smaller size, lack of warm-up time, and lower power consumption (i.e.,
less heat). Prices were about the same at the beginning of the technology transition.
Some anti-semiconductor naysayers tried to argue that at least with tube equipment
you had a chance of fixing a malfunctioning unit simply by replacing a $1 tube,
but failed to note that the equivalent semiconductor product almost never experienced
a failure. Of course there were some crappy transistorized products, but that was
the exception rather than the rule...
 Sprague Electric engineer Benedict Rosen,
discusses how the characteristics of a circuit in need of protection against RF
interference needs to be considered when selecting filter components. He points
out that attempting to hang a shunt
feedthrough capacitor on the input and/or output of a low impedance
(e.g., 50 Ω) RF circuit could make the situation worse, depending on whether
the circuit is strongly capacitive or inductive in its out-of-band region. Sprague
was a major manufacturer of all sorts of capacitors qualified for use in military
and aerospace systems, so they put a lot of effort into characterizing device parameters
over a wide range of voltage, current, power, temperature, mechanical, and frequency
environments...
 Nationwide survey shows a
decline in opportunities for engineers. Although jobs are fewer and requirements
tougher, certain specialists are still in demand. An employment-agency official
on Long Island says, "If it weren't for Grumman (Aircraft Corp.), you could just
cut Long Island off and let it float into the Atlantic." A Chicago agency that specializes
in jobs for engineers advises applicants to relocate and be prepared to drop out
of the five-figure salary range. These are typical findings in a coast-to-coast
employment survey. Don't panic; these statements are from a 1964 issue of Electronics
magazine. Prior to our current Era of Wireless, which, unbeknownst to most people,
is a nomenclature that harkens back to a century earlier...
 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+ 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...
 I have mentioned this before, but nearly
always the setting for John Frye's "Mac's Service Shop" technodrama stories coincide
with the time of year corresponding to the month in which it appeared (for the northern
hemisphere) - in this case the July 1952 issue of Radio & Television News
magazine. In addition to that, Barney's crack about Mac using his slide rule to
try calculating who the president would be is also time-appropriate since 1952,
being a Leap Year, was also an election year (Eisenhower beat Stevenson, BTW) ...but
I digress. Mac's actual preoccupation was with
open wire transmission lines. With the rise of UFH broadcasting on the horizon,
he predicted that such lines would become popular due to their lower signal attenuation
compared to standard 300 Ω plastic-insulated twin lead. Open line (aka ladder
line or window line) at 500 MHz exhibits about a quarter the loss when dry
and as much a twentieth the loss when wet (depending on the quality of the standard
300 Ω twin lead)...
 Prior to news of the A-bombs dropped at the
end of World War II, most people had no idea what nuclear anything was. My
guess is school textbooks made scant mention of it mainly because what was known
of the science was kept under wraps at the Department of War. The Department of
Energy (DoE), which currently administers nuclear policy and oversight, did not
formally exist as a separate entity until 1977. Per their website, "Although only
in existence since 1977, the DoE traces its lineage to the Manhattan Project effort
to develop the atomic bomb during World War II, and to the various energy-related
programs that previously had been dispersed throughout various Federal agencies."
In 1955 when this episode of "Mac's Service Shop" appeared in Radio & Television
News magazine, one of the popular items for electronics hobbyists was Geiger
counters (along with metal detectors)...
 This is another example of a multi-part article
of which I happen to have discovered only one of installments - Part 9. As is often
the case, each article is pretty much stand-alone and does not require that you
have already seen the previous sections. In 1951, computers were still mostly analog;
digital circuits were just beginning to get serious research thanks to the recent
advent of solid state devices. Boolean algebra, truth tables, and combinational
logic were just beginning to be taught in engineering courses.
ENIAC (Electronic Numerical Integrator and Computer), first used in 1945 at
the end of World War II, was the world's first general purpose digital computer,
and its active elements were vacuum tubes - about 20,000 of them. As you might expect,
there was a lot of excitement in the electronics, scientific, and finance world
about digital computers that would be inexpensive enough that individual corporations...
 Since we seem to be on a roll of FM radio
theme articles printed in vintage electronics magazine, here is one from a 1973
issue of Popular Electronics. The author never explicitly tells us the date when
the Institute of High Fidelity (IHF) updated its
FM tuner specifications, and neither does he mention groundbreaking work of
IHF's Julian Hirsch, who is largely responsible for both the initial and updated
standards. If you read magazine stereo equipment reviews in the 1960s and 1970s,
then you probably recall the name. Anyway, this article discusses the improved specifications
made possible by more sophisticated circuits made possible by semiconductors and
miniaturized passive components. Interestingly, by 1973 magazines had gone from
abbreviating decibels from d.b. to dB, from k.c. and m.c. to kHz and MHz, from m.m.v.
to (μV), and from r.f. to RF, but they still used i.f. (intermediate frequency)
rather...
 Amateur radio operators have been blamed
for a lot of radio frequency interference (RFI) and
television interference (TVI) over the years, with some being
justified and a lot being unjustified. The surest sign that a Ham set is interfering
with your entertainment box is when you actually hear voice or a series of dits
and dahs. However, when the interference is a steady or waver buzzing sound or scratchy
intermittent hash, chances are greater that the interference is coming from a noisy
motor in a vacuum cleaner, a kitchen blender, a power tool, or an arcing power line
transformer / cracked insulator. The American Radio Relay League (ARRL) has jumped
through burning hoops (figuratively) to educate licensed operators on how to avoid
complaints by assuring gear is functioning properly, and educating the public about
the likelihood that the problems they experience are not coming from the guy down
the street with big antennas in the yard but from the next-door neighbor's swimming
pool filter pump...
 As one who many moons ago (1970s) used to
make
service calls to people's homes (as an electrician), I can relate to some of
the stories like the ones which appeared in various issues of Radio News
magazine in the 1930s and 1940s. For that matter, most of the trade magazines ran
similar pieces. This saga of course is most likely not a for-real experience, just
a humorous tale of the kinds of scenarios sometimes met by on-site servicemen. The
laissez-faire attitude of the star of this story made him deserving of the treatment
he received from the customer. In fact, my attitude was always one of extreme courtesy,
respect, going beyond the call of duty to do a good job, and performing my work
as efficiently as possible. It put me in good stead with my employers because of
favorable comments from home and business owners. One notable exception was one
lady who sent me away when I met her at the door with my pre-USAF long hair...
 Most
professional engineers and technicians will never have the need to calculate the
capacitance, inductance, or impedance of a
coaxial cable since they are
usually designing systems using well-defined components that are manufactured to
exacting specifications. Students, hobbyists (Ham radio operators), and research
types are probably the ones most likely to actually plug numbers into a calculator.
For those people, I present these equations. Be very careful to realize that at
frequencies far from DC, factors like skin depth and effective inner and outer conductor
diameters may be significantly different than the physical measured values, and
that can significantly affect real world results. Therefore, be sure to consult
manufacturers' published data before making a final decision. I leave it to other
sources to provide the complex equations needed to precisely model coaxial cables...
 The
Old Farmer's Almanac (OFA) has been on my annual need-to-buy list for as long as
I can remember. It is chock full of useful data for sunrise and sunset times, high and
low tide times, crop planting days, first and last frost days, and significant astronomical
events. There are stories of interest on topics ranging from canning your garden's harvest
to how to view a solar eclipse. - often from noted authors, but also from lay people.
I also enjoy the monthly "on this day" type tidbits and the homey short story relating
to the time of year. After 225 years of continuous publication, it still features the
hole in the upper left corner to facilitate handily hanging it on the wall of your shed
-- or outhouse. I gave a 1961 edition of the Old Farmer's Almanac found on eBay to Melanie
as a birthday present this year... |
