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 Here is a good
quiz that tests your knowledge of classifications of science fields.
It appeared in a 1949 edition of The Saturday Evening Post magazine. Even
if you do not particularly know the relationships, you should be able to get most
if not all twelve correct with a combination of surety, recognition of word roots,
and a process of elimination. Good luck...
 ConductRF is continually innovating and
developing advanced solutions for RF cable assembly and various RF through millimeterwave
interconnect requirements. We'll be posting their latest RF cables and technical
articles here at RFcafe.com, but to stay abreast, you're encouraged to visit their
Updates section at https://www.conductrf.com/blog
and sign up for their monthly news releases.
 During the early 1960s, Short-Wave Listening
(SWL) was a remarkably popular era-defining hobby, as enthusiasts worldwide competed
to pull in distant broadcasts from London, Moscow, or Hong Kong. "How
to DX Satellites" challenged these listeners to advance beyond Earth-bound stations
to the ultimate frontier: intercepting signals from orbiting spacecraft. While skeptics
dismissed satellite DXing as impossible due to extreme distances, low power, and
elusive verification, the author maintained it was achievable for those with the
right patience and gear. Successful monitoring required sensitive communications
receivers, crystal calibrators...
 Radio Shack,
like so many of America's original great companies, was born and lived long and
prospered during its glory days, then eventually waned into insignificance and obsolescence
within the last decade or so. It is not always simply an unwillingness to adapt
to new technologies and methods that dooms them. The forces behind those life cycles
are often beyond their control because start-ups vying for market share do not carry
the burden of and have to deal with established investments in people, facilities,
and infrastructure...
 Although obviously (but getting less so)
before my time, the mention of this airborne radar surveillance system having been
built by
General Electric, in Utica, New York, struck a chord since that
is where I had my first engineering job after having graduated from the University
of Vermont with a BSEE degree. It seems to me the work at the time was all done
in the converted textile complex on Broad Street. They were the glory days of GE,
Westinghouse, Collins, Raytheon, and other electronics titans whose engineers, technicians,
assemblers, and program managers...
 The June 1949 issue of Radio & Television
News had four
television-themed comics. Television at that time was a relatively
new home appliance, so there was a huge amount of interest in the technology. It
hadn't really been all that long since the public got used to hearing sound (i.e.,
'talkies') in the movie theater, so the mystique that surrounded television made
it the subject of a lot of puns and jokes. 1949 was a mere four years after the
end of World War II, and the post-war economic boom was primed by a surplus
of left-over electronic components along with lots of available talent both in the
areas of design and assembly...
 Temwell is a manufacturer of 5G wireless communications filters
for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining
transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting
(CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000
completed spec sheets online for all kinds of RF filters including helical, cavity,
LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer,
multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators,
couplers, PA, LNA, and obsolete coil & inductor solutions.
 Both my father and grandfather were
stamp collectors - philatelists is the technical word - who dabbled
in a recreational way with commemoratives from foreign countries. Nearly all were
canceled (used) stamps that today, as back in their
day, have no real value other than to someone interested in history. Of course none
are the rare types. I now possess many of those stamps in an album that was painstakingly
hand-illustrated and assembled to arrange each stamp according to its country and
issue date. At one time I, too, dabbled in the hobby, having collected many plate
blocks and special issue U.S. stamps in the 1970s and 1980s, along with purchasing
a few designs of special purpose such as those with aerospace and communications
themes...
 Exodus Advanced Communications offers a
scalable portfolio of
high-power solid-state RF amplifiers designed for electronic warfare, GPS/GNSS denial,
and counter-drone applications. These systems are engineered to support high-power
RF denial architectures capable of disrupting control, navigation, and payload links
across multiple frequency bands. Integrated into mobile, fixed, and expeditionary
platforms, Exodus amplifiers enable reliable, long-range electronic attack performance
in complex and evolving threat environments. These solutions are deployed within
high-power RF denial systems across mobile and fixed counter-UAS platforms, as illustrated...
 "Measuring low-frequency electric fields
with high precision remains a significant challenge. Existing sensing technologies
often cannot deliver traceability, compact design, and the ability to detect field
direction all in one system.
Rydberg atoms are gaining attention in electric-field quantum metrology because
they have large electric dipole moments and their behavior can be tied to well-defined
atomic properties. Most current methods for detecting low-frequency or DC electric
fields using Rydberg atoms rely on vapor-cell electromagnetically induced transparency
(EIT) spectroscopy. However, this technique is limited..."
 Here are the
Majestic Chassis Models 380 A.C. T.R.F., and 400 A.C.-D.C. Superheterodyne
and
Delco 32-Volt Radio Receiver Chassis Radio Service Data Sheets
as featured in a 1933 edition of
Radio-Craft magazine. 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. Even with the availability
of SAMS Photofacts, there are some models that cannot be found anywhere other than
in these vintage magazines...
 For the sake of avid cruciverbalists amongst
us, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics, chemistry,
physics, and other technical words. You will never be asked the name of a movie
star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Clues
in this week's puzzle with an asterisk (*) are directly from this week's "High Tech
News" column on the RF Cafe homepage (see the Headline Archives page if necessary)...
 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.
 In 1961, when these
tech-themed comics appeared in Electronics Illustrated magazine, the
"Space Race" was in full swing. That, along with home hi-fi stereo equipment, newfangled
color televisions, and - gasp - transistors, filled the headlines. They were also
the subject of many forms of humor. These four comics touch on many of those aspects,
all centered on the Space Race. Of course, everything is noticeably dated. "Flunking
the code test" means not much to Amateur radio licensees who earned their first
license (like me, in 2010) after the 5 WPM Morse code requirement was removed. Building
something in "kit form" was a good way to save some money and learn something...
 In our present "No user serviceable parts
inside" world of electronic products, it is easy to understand why very few people
have an appreciation for the technical prowess needed to troubleshoot and repair
them. When reading through these episodes of "Mac's Radio Service Shop" that appeared in mid last century editions
of Radio & Television News magazine, I am inspired to envy the skills
that small electronics repair shop owners had for working on the old vacuum tube
based radio and television sets. Digital electronics has its own unique set of quirks
and special knowledge requirements to troubleshoot, but when everything is analog
rather than merely being required to be a "0" or a "1"...
 "The U.S. Federal Communications Commission
(FCC) has announced that it is once again accepting applications for its
Honors Engineer Program. Initiated in 2018, the one-year development program
gives selected candidates an opportunity to work with FCC personnel on innovative
issues in the communications and high-tech arenas, including 5G communications technology,
the national deployment of broadband services, and communications technologies intended
to improve access to those with disabilities. Those selected to participate in the
Honors Engineer Program will be eligible for continued employment at the agency.
Application to the FCC's Honors Engineer Program is open to recent college graduates
with an engineering degree..."
 This week's crossword puzzle theme is
Amateur Radio. All RF Cafe crossword puzzles are custom made by me, Kirt
Blattenberger, and have only words and clues related to RF, microwave, and mm-wave
engineering, optics, amateur radio, mathematics, chemistry, physics, and other technical
subjects. As always, this crossword puzzle contains no names of politicians, mountain
ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she
is related to this puzzle's technology theme...
 Submarines first proved their deadly capabilities
during World War II when Adolph Hitler's navy used them to torpedo not just
military ships but merchant ships in commercial trade routes between the Americas
and Europe. Hideki Tojo's navy used subs to conduct surveillance prior to the deadly
surprise attack on Pearl Harbor. Their naturally stealthy environment - underwater
- proved to be a difficult realm both for detection and for attack. Fortunately,
sensor technology developed quickly during the war, and soon a combination of air
and sea based methods were in use and proved very effective. Submariners no longer
sailed in relative security from being treated to a violent, icy burial at sea...
 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.
 As
the Soviet army closed in on the Peenemünde rocket base in March 1945, German engineers
led by
Wernher von Braun initiated a desperate evacuation of their revolutionary research.
Tasked by von Braun, engineer Dieter Huzel organized the transport of tons of top-secret
blueprints and records to avoid capture by the advancing Red Army. Amidst the chaos
of collapsing lines and aerial warfare, Huzel successfully secured the documents
in an abandoned, ironclad mine near Goslar, shielding them from Soviet hands. After
dynamiting the entrance to seal the cache, Huzel and fellow scientists fled westward
to surrender to American forces. Following their successful arrival in U.S. lines,
the location was revealed...
 Sending telegraph messages, whether by wire
or wireless means, has always been expensive, particularly considering charges are
determined by the character (letter, number, symbol). Accordingly, the Shakespearean
line from Hamlet declaring that "brevity is the soul of wit" can be reworked to
"brevity is the soul of economy." A telegraph wire, unlike a telephone call, is
a legally binding communiqué, as is of course a written letter, but a telegram is
immediate transmission of information for time-critical messaging. A series of "commercial codes" were developed enabling senders to save often
significant money by sending multi-character codes that represented entire phrases
and/or sentences. What struck me about this article that appeared in a 1948 issue
of The Saturday Evening Post magazine...
 "With all the many pressures you have as
a product designer, does
electromagnetic
compliance (EMC) always seem like a stumbling block to delaying product sales?
Is your product exhibiting one of the top three failures: radiated emissions, electrostatic
discharge, or radiated immunity? Are you continually cycling between design/fixing
- running to the compliance test lab - failing again - and back to shot-gunning
more fixes? Wondering how to attack these issues earlier in the design cycle? Would
you like to learn how to characterize and troubleshoot simple design issues right
on your workbench? Then, this monthly column is for you..."
 In 1938, the designers at Sears, Roebuck &
Company's, Silvertone radio division were truly thinking "outside the box" when
they came up with this "Rocket" model
Models 6110. It is an ultra compact tabletop design with a unique
rounded top and a huge tuning dial that comprised one entire end of the Bakelite
cabinet, along with a set of six pushbuttons for station recall. Also published
were datasheets on the
Allied Radio Knight Model E10913, the
General Electric Model GD-52,, and the
Zenith Models 6D302, 6D311, 6D326, 6D336, 6D360. An ever-growing
list of models is at the bottom of every page...
|
 • How
Test and Measurement Will Evolve in 2026
• AI
and Geopolitics Forge Memory Market Crisis
• European
Electronics Distribution Gains Momentum
• UK
Secure Quantum Communications Boost
• 2026
PC Sales down 11.3%, Tablets down 7.9%
 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.
 The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has a Butterworth
Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but
also phase and group delay! Since 2002,
the original Calculator Workbook has been available as a free download.
Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is
also 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
(VBA) 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...
 Here is an amazingly detailed article on
how to construct and operate a near-lab-quality
impedance bridge out of relatively inexpensive components. It appeared in a
1944 issue of QST magazine. A bridge is used to determine the precise value of a
resistor, capacitor, or inductor. Prior to modern, easily affordable digital impedance
meters, both amateurs and professionals relied on such devices for lab and field
work. Why might you need to measure the value of a component when most are marked
with a value? One common application is when a variable version of a component (or
components) is soldered into the circuit while tweaking for optimal performance,
and then the variable is replaced either with a single fixed component or a fixed
component with a smaller-range variable component. It is not uncommon when doing
the initial tuning on a complete home-built transceiver to have many variable components
in place initially, and then solder in fixed versions later...
 Windfreak Technologies is proud to announces
the availability of our
FT108, an innovative
programmable bidirectional filter bank spanning a frequency range of 5 MHz
to 8 GHz in 15 bands. Band selection can be controlled through USB, UART or
at high speeds through powerful triggering modes. Each unit is factory tested via
network analyzer with unique data stored in the device to help with its use. Crossover
frequencies are stored so the user can send a frequency command and the FT108 will
utilizes Intelligent Band Selection logic to automatically toggle the optimal
filter path based on minimum insertion loss. Readback of FT108 insertion loss at
any frequency between crossover points allows for easy amplitude leveling...
 RF Cafe visitor and former Watkins-Johnson
engineer Paul Johnson (no relation to the "J" in WJ), recently sent me this note
regarding the Watkins-Johnson catalog page that contained the famous "Phase
vs. VCTL vs. Frequency vs. Phase of the Moon" graph on the WJ-G1/SMG1
Voltage-Controlled Attenuator Module (5 to 2,000 MHz). We all suspected it was
not an officially approved feature, but now a first-hand account of the prank
confirms it...
 Thanks to J.C. for providing three more
of the
Varian
Associates radar comics - that's a total of twenty thus far. The original text
on these is in German poem form, so the Google translations have lost some context.
Fortunately J.C., a German who lives in Germany, provided a translation in modern
lingo. A few years ago, another frequent RF Cafe visitor who goes by the moniker
"Unknown Engineer" sent me a hyperlink to a PDF file on Amazon's CloudFront content
delivery network (CDN - basically a file server) that contained no fewer than 17
amazing radar and vacuum tube related line drawings published by Varian Associates'
TWT Division, Palo Alto Tube Division, Solid State Division, Eastern Tube Division,
Western Tube Division, Solid State West Division. These highly detailed and busy
drawings were done around 1975 by British illustrator/artist C.E.B. Bernard; a search
for his works did not reveal much. The events shown are fictitious, as are the accompanying
hand-printed stories. Some of the puns are pretty clever, but are somewhat dated
for today's readers...
 As always, the reading of this
Mac's Radio Service Shop techno-saga leaves you a little bit smarter about an
aspect of electronics as well as how to approach business from both the serviceman's
and the customer's perspective, with a bit of humor and personality thrown in for
good measure. Author John T. Frye, who also wrote the long-running and much-loved
Carl & Jerry series, uses service shop proprietor "Mac" McGregor as a sort of
alter ego for passing on his own extensive knowledge of radio and television servicing.
Customer satisfaction is the main theme of this installment, which entails going
beyond just repairing the problem the items is brought in for. Mac instructs his
young wingman technician Barney to run a series of standard tests on every set in
hopes of ferreting out...
 America's first successful orbiting of a
satellite launch happened on February 1, 1958 with the launch of Explorer 1
atop a Juno 1 rocket. Our first attempted satellite launch was the Vanguard TV3,
on December 6, 1957, but it unfortunately succumbed to a failed booster rocket (it
rose only 4 feet off the launch pad). Russia had already launched its Sputnik 1
satellite on October 4, 1957, making it the very first manmade satellite to orbit
the earth - to the forever chagrin of U.S. scientists. Fortunately, advances occurred
rapidly for the U.S. space program after Explorer 1. In its first full decade
of existence, the
Goddard Space Flight Center, located in Greenbelt, Maryland, was responsible
for launching more than 100 different spacecraft...
 The ability to generate clean, controlled
radio waves at 3 THz in 1937 was about as attainable as putting a man on
the moon. That did not stop scientists and engineers from theorizing how to get
there and what to do once attained. That's the way science progress happens. An
official name had not yet been given to the spectrum realm, but news reporters conjured
up the moniker "mystery rays." Even scientists called it the "black gap." Both sound
a bit hokey and there is a temptation to poke fun at the renowned technical ignorance
of most media types, but no less a science giant as Albert Einstein referred to
quantum entanglement as "spooky action at a distance." The big idea of author W.E.
Shrage was to exploit and extend the concept of a cathode ray tube (CRT) to convert
streams of electrons into a visual image to use a photosensitive surface to directly
convert (no mixing to an IF) terahertz radio waves modulated with audio directly
into sound...
 Genius
takes on many forms, not the least of which is the ability to concoct and compose
an [almost] believable a story describing in the utmost detail the technical workings
of a complex mechanical gadget. Items such as a mizule wrench, meta-phasic shielding,
blinker fluid, a left-handed screwdriver, and - one of my favorites - the muffler
bearing, have been heard in comic routines... er... routinely. No matter how many
times you hear them you always laugh again. Some are actually a portmanteau and
just sound funny while others are completely made up. This
Digital Decabulator article that appeared in a 1966 issue of
R/C Modeler magazine is amazing; it pegs the B.S. detector from beginning
to end...
 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...
 Hmmm... this is the first time recall either
of Carl's or Jerry's father, at least where either was present in the story. Their
mothers are mentioned on occasion for providing sandwiches or uttering words of
caution when embarking on a sleuthing mission. In this episode entitled "Two Tough Customers," creator and author John T. Frye have
the techno-teens set out on an adventure to shop for a good deal on a fundamentally
sound car - which they would own in a partnership set up by their fathers. As you
would expect if you are an ardent C&J follower, their effort includes inspecting
not just the mechanical integrity but also the electrical system health. Frye always
used his stories as the basis for a lesson on some technical aspect of everyday
life. The boys broke teenage car owners into three groups: Hot-Rodders, Show-Offs,
and Mechs. They seemed to assign one trait or the other, but not a combination
thereof. Personally, I was a bit of all three with my first car - a 1969
Camaro SS. While reading, see if you notice what I did about the battery
measurement...
 Satellite evolution occurred at a rapid pace once
Sputnik and Echo were successfully launched in the late 1950s. Sputnik was a simple beacon
transmitter whose signal was used to measure orbital and atmospheric properties and their
effects on radio signals. Oh, and also to announce to the world that the USSR had accomplished
the world's first satellite mission - I'd brag, too. Explorer 1, the first
U.S. satellite, launched the following year, measured and broadcast Van Allen Radiation
Belt data. This Electronics World article appeared about a decade into the satellite
aspect of the "Space Race." By then...
 A lot of nostalgia gets waxed here on RF Cafe,
to which frequent visitors can readily attest. Old timers (if you're not one now, you
some day will be) often like to see remembrances of days of yore, the halcyon days of
past hobbies, family, long naps, school (yuk), vacations, and other pleasurable times.
Hopefully, you already have or will soon have a few of your own. This 3-page
Lafayette Radio Electronics spread from a 1965 issue of Popular Electronics
magazine is typical of what what avid electronics hobbyists would have read and
drooled over with so many great items in the offering. If you were like me, the
cost of most of the things I wanted were well outside my budgetary reach. Prices
for electronics gizmos were quite high...
 While listening to the radio the other day,
I heard a guy who is very technically astute and is a Ham radio operator pronounce
the word "schematic" as "skem-E'-at-ik." He wasn't just joking because he kept saying
it that way throughout the show. It came to mind while posting this chapter entitled,
"The
Electrical Circuit Diagram," and I thought you might appreciate it (especially
if you also routinely mispronounce the word). But I digress... The U.S. Navy over
the years has produced a number of series of training courses for electricity, communications,
mechanics, navigation, etc., that are held in high regard by the military and private
industry. Graduates of the courses who served a term of enlistment performing equipment
maintenance have always been preferred by employers looking for high quality technicians... Sunday 17
 For two decades, I have been creating custom
engineering- and science-themed crossword puzzles for the brain-exercising
benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. This November
17, 2019, puzzle uses a database of thousands of words which I have built up over
the years and contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing
your knowledge of a numbnut soap opera star or the name of some obscure village
in the Andes mountains. You might, however, encounter the name of a movie star like
Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons
which...
 Here is a simple JavaScript routine that
converts between frequency and wavelength in the electromagnetic field realm. Wavelength
and frequency are related by the following formula: c = λ * ν * √εr ; where c =
speed of light, λ = wavelength, ν = frequency, and εr = relative permittivity. Here
are some familiar objects and their equivalent wavelength-related frequencies in
air...
 When the electronics product world consisted
of vacuum tube based circuits, the physical sizes of standard fixed-value passive
resistors, inductors, and capacitors were not of much concern in terms of
how much volume they consumed. R's, L's, and C's, had wire leads protruding from
their molded bodies, or in the case of larger power supply filtering capacitors
had solderable tabs. Point-to-point wiring consisted of components and hookup
wire suspended in the air between solder terminal strips and tube base tabs.
Even with miniature (peanut) tubes, all but the largest passives had no
significant impact on overall unit size. Once semiconductors came onto the
scene, everything changed. Suddenly, even the standard 1/4 W carbon resistor and
tantalum capacitor became a significant factor when attempting to reduce size...
 Commercially available radio receivers for
the home had only been around for a couple decades when this advertisement from
Crosley appeared in a 1932 issue of Radio-Craft magazine. I keep looking
in old electronics magazines for an ad featuring my 1941 Crosley model 03CB console
radio, but thus far with no luck. There is a chance, although I have not seen any
direct evidence of it, that the 03CB chassis was sold as a special upgrade to the
less ornate 02CA model. What makes it special is that it was probably one of the
last new radios sold prior to the shift of material usage to military equipment
in World War II...
 Listen to the RF
Cafe Podcast! "The Whistler and His Dog" is one of those tunes that you have
probably heard dozens of times but never knew the title of it (video at bottom of
page). It is mentioned in this installment of "Mac's
Radio Service Shop" from the November 1948 edition of Radio & Television
News magazine. Barney is said to have been whistling it while replacing an
output transformer on a receiver-recorder... a wire recorder that predated magnetic
tape types. The "20 Questions" theme is from the game where the player attempts
to guess the answer by asking a series of questions that narrows the possible results
until only the correct one is left - aka deductive reasoning... |
