|
 Popular Electronics magazine printed
in April 1966 its first notice of
new frequency units to be used beginning with the June edition.
The May issue included this piece titled, "Comes the Revolution - or - '40 Million
Frenchmen Can't Be Wrong'." Predictably, not everyone liked it. With the
June issue came the promised change and along with it the first in a series of reader
responses. I also found a reader's opinion from the August issue as well. Evidently,
not everyone wanted to honor Heinrich Hertz by naming the base unit of frequency
in his honor...
 "Eventually," Dr. Herwald said, "we believe
it will even be possible to automatically and continuously produce actual electronic
equipment, such as radio receivers and amplifiers, starting from a pool of molten
semiconductor materials." That was in early 1960 in an Electronics World
article titled, "Molecular Electronics." The term "molecular" references what eventually
became integrated circuits (IC), the first of which was realized in 1958 by Texas
Instruments engineer Jack Kilby. Kilby's IC incorporated one transistor, one
capacitor, and three resistors on a germanium substrate. Building on that success,
researchers envisioned single-chip semiconductors which contained hundreds, thousands,
and even millions of transistors, diodes...
 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 models have been added to the product line in June, including
a 9660 MHz (COM1 - COM3) cavity bandpass filter, a 2442 MHz waveguide
band stop filter, and a 2072.5 MHz / 2250 MHz / 1800 MHz triplexer
filter. Custom RF power filter and directional couplers designs can be designed
and produced with required connector...
 I suppose a more appropriate title for this
chart would be "Foreign Valve Substitution Data," considering that most (if not
all) of Europeans refer(red) to vacuum tubes as "valves." As with having posted
scores of Radio Service Data Sheet pages for the benefit of hobbyists who restore
and service vintage radio equipment, I also post other hard-to-find reference resources
when I find them. Sure, the number of people looking for this information is extremely
small, but they are extremely grateful for this when in the throes of finding replacement
tubes (valves). Posting a hyperlink to this page on the RF Cafe homepage will assure
that...
 My father used to refer to the "sweet-voiced
lady predicting the weather over and over again" as my girlfriend because I would
call the "WEather 6-1212" phone number (936-1212) so often. It really wasn't
because I was infatuated with her voice, it's that I was obsessed with weather forecasting.
Most of my free time as a kid and teenager was spent building and flying model airplanes
and rockets, and at eighteen years of age I began taking full-size aeroplane flying
lessons, so my world revolved around a zone extending from terra firma up to about
5,000 feet AGL. This collection of communications news...
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
 Welcome to the
RF Cafe
Isolators & Circulators Quiz, an essential assessment for engineers focused
on the reliable sampling and monitoring of signal flow. Directional couplers are
the cornerstone of power metering, reflected power detection, and signal injection
in high-frequency transmission systems. Whether you are calibrating a forward-power
monitor, auditing VSWR in a feedline, or balancing a complex signal distribution
network, a rigorous understanding of coupling factor, directivity, and insertion
loss is vital. This quiz challenges your knowledge of these passive structures,
covering the mechanics of coupled transmission lines, the significance of isolation
and directivity, and the critical trade-offs in power splitters and tap networks.
By evaluating your grasp of these core principles
 Werbel Microwave's
WMADC-0.38-3-40DB-SERIES is a high-power 40 dB directional coupler covering
380 to 3000 MHz, supporting a wide range of VHF, UHF, cellular, LTE, and wireless
infrastructure bands. Built on an air dielectric coaxial structure, this design
delivers low insertion loss, excellent power handling, and exceptional directivity
for accurate forward and reverse power discrimination. Unlike many broadband couplers
that prioritize ultra-flat coupling, this model is engineered to maximize directivity
across the band, ensuring cleaner separation between forward and reflected signals.
In most real-world systems, coupling variation is easily calibrated out...
 The
medical x-ray machine shown here reminds me of the "Illudium Q-36 Explosive
Space Modulator" contraption Marvin the Martian wanted to use in "Hare-Way to the
Stars" to disintegrate the Earth (because it blocks his view of Venus). Of course
our hero Bugs Bunny thwarts his plan, whereupon Marvin asks, "Where's the kaboom?"
Can you imagine being fraught with cancer and getting strapped into a chair with
that huge hypodermic-needle-looking thingy pointed at you, as shown in this 1959
issue of Popular Electronics magazine? The Caduceus sword in the pic doesn't
help matters, either. The trauma of such an experience might have been worse than
the treatment for some people. As usual the pioneers took the arrows so that we
can benefit from the treatments enjoyed today, and the equipment does not look nearly
as intimidating. See also "After Class: X-Rays" for more info...
 A wee bit of levity in the form of comics
is good for the soul on a busy workday.
Good humor, it is said, contains a degree of truth in it, and this group from
vintage editions of Radio-Craft magazine is no exception. One of the comics
in particular struck a chord with me - the one with the table model radio where
the serviceman is speaking on the phone with his customer. The first familiar feature
is the shape of the radio and the removed rear cover; it reminds me of my Tesslor
R-601S. The second thing is the dead bugs. Just like a stray cat will climb into
your car's engine compartment on a bitter cold day in search of heat, so will
bugs be drawn to a heat source such as that provided by an electronic appliance
filled with warm, glowing vacuum tubes...
Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
 The concept of
exploding wire propulsion is a fascinating relic of the early Space Age concepts,
reflecting an era of high-energy-density experimentation that prioritized power
density over long-term system efficiency. While this 1962 Electronics Illustrated
magazine report captured a valid physical phenomenon - the rapid plasma expansion
of a metallic conductor - the practical implementation for spacecraft encountered
insurmountable engineering hurdles relative to the chemical and electrical propulsion
benchmarks that followed. When you dump several thousand amperes into a 1-mil wire
in nanosecond timescales, you bypass traditional heating...
 Here is another article about a
"prodigal" Ham who returned to amateur radio after about a 30-something year
respite, per this 1955 Popular Electronics magazine. Author Charles Meistroff's
previous experience had been with surplus World War I - yes that's WWI! He must
have been in Heaven to be able to now get his hands on all the new-fangled equipment
now (then) available on the World War II surplus equipment market! I don't know
if the military is still making surplus equipment available like they did even up
through Korea and Vietnam. There must be some great stuff from the Middle East wars
if it is circulating within the surplus market. Then again, other than ruggedness
factors, most commercial equipment is as good or better than MIL-SPEC stuff...
 "If the car is parked in a dark remote spot
it is better to do the job where the car is. This is because auto burglary is a
lesser crime than stealing the whole damn car." That remark was made by a 'former'
thief who ostensibly gave up a life of crime after spending nearly two decades in
the slammer for various infractions of the law. One of his specialties was breaking
into cars to steal radios - AM, FM, CB, Ham, or whatever was available. Mr. X
volunteered his insight for the benefit of QST readers who might want to take proactive
steps to help minimize the chance of being a victim. The year was 1967, but you
can bet the same mindset pervades the thinking of modern day break and grab thieves
today. Even though most modern portable electronics equipment is protected from
access by passwords, that wouldn't stop a thief from stealing...
 Prior to the emergence of
silicon-based semiconductors, selenium and copper(cuprous)-oxide
rectifiers were the alternatives to vacuum tubes. Copper-oxide (Cu2O)
was popular as a small signal detector since its forward voltage drop was similar
to a Schottky type diode - typically around 0.2 V. Copper-oxide diodes were
used in radios and test equipment meters. Selenium (Se) has a forward voltage drop
of around 1 V, but its high reverse voltage withstanding of 20 V or more
made it popular for voltage rectification, with as many layers as necessary being
stacked serially as required. Selenium rectifier stacks...
 Centric RF is a company offering from stock
various RF and Microwave coaxial
components, including attenuators, adapters, cable assemblies, terminations,
power dividers, and more. We believe in offering high performance parts from stock
at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500
watts are available off the shelf. We have >500,000 RF and Microwave passive
components we can ship you today! We offer Quality Precision Parts, Competitive
Pricing, Easy Shopping, Fast Delivery. We're happy to provide custom parts, such
as custom cables and adapters, to fit your needs. Centric RF is currently seeking
distributors, so please contact us if interested. Visit Centric RF today.
 Welcome to the
RF Cafe Coaxial Cable
Quiz, a technical assessment designed to sharpen your proficiency in the fundamental
transmission media that underpin all radio frequency communications. Whether you
are scaling a tower for antenna installation, troubleshooting impedance mismatches
in a feedline system, or calculating loss budgets for a long-run cable deployment,
a firm command of coaxial theory is vital for maintaining signal integrity and power
efficiency. This quiz challenges your understanding of critical transmission line
metrics, including characteristic impedance calculations, the impact of dielectric
constants on velocity factor, the physics of the skin effect, and the thermal limitations
of power handling. By testing your knowledge...
 If you were hanging around here in 2014,
you might recall a paper I published titled, "Drone-Based Field Measurement System™ (dB-FMS)™." Since that time,
I have seen news items about a few companies using drones to measure antenna radiation
patterns and many more others are coming online all the time. Some amazing working
systems have been implemented that seem to perform very well. I'm not saying
they got the idea from my article because more than one person can have the same
brilliant idea ;-). It's just good to know that my concept had some merit in
the real world...
 My
Vise-Grip pliers have performed a lot of hard duty over the decades.
Many rusted nuts and bolts would still be unremoved if it weren't for their
sharp, corrugated locking jaws. I have 10", 7", and 4" w/cutter, and 6" long nose
models. These are all manufactured under the Petersen Manufacturing Company name,
before they bought Irwin, who now manufactures Vise-Grips. Even high quality tools
eventually show signs of wear after decades of use and abuse. A few of mine had
jaws worn down to the point where they no longer would "bite" into the bolt head
or nut being clamped. I was about to buy a couple new pairs of Vise-Grips, but then
wondered if I could recondition the jaws to put the pointed shape back on the jaws
with a triangle file. Being hardened steel, a lot of times a standard file will
barely scratch the surface, but in this case I managed to dress the jaws of four
pairs of Vise-Grips before the file (double taper triangle) got dull...
 "Stratovision" sounds about as serious as "Wonkavision," but unlike
the candy maker's fictional machine that transported chocolate bars across the
room, Stratovision was in fact a serious proposal. It was an early form of satellite
television. Since orbiting communications satellites would not be practical for
another decade, Westinghouse devised a system in 1945 using aircraft flying at high
altitude to relay television signals. Engineers calculated that 14 airplanes circling
at 25,000 feet could provide coverage to 78% of the country. By 1950 they had a
working system, but needless to say (because nobody has ever heard of it... except
you, now), the concept ultimately did not pan out. It was not because the system
failed to work as designed, but because there was not enough demand...
 Werbel Microwave is a manufacturer of
RF directional and bidirectional couplers (6 dB to 50 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.
 According to this full-page advertisement
in the June 1955 issue of Radio & Television News magazine, Bell Telephone
Laboratories was responsible for designing and fielding "waveguide pipe," aka flexible circular waveguides. According to
other historical sources, both George Southworth of Bell Telephone Laboratories
and Wilmer Barrow of the Massachusetts Institute of Technology (M.I.T.) independently
and simultaneously developed circular waveguide, but the early devices were rigid
pipe rather than being fabricated from tightly wrapped, insulated wire that permitted
it to be bent rather than requiring separate corner and offset pieces. Insertion
loss and VSWR is typically not as good as with rigid waveguide, but the ease of
installation in many situations justifies the poorer electrical performance. Bell
Telephone Laboratories was responsible...
|
 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.
 OK, class, put your books away and take out
a pencil. Spread your chairs out because we're going to have a short test today.
A collective sigh permeates the room. Remember those days? I still have nightmares
over those moments, and they were decades ago for me. At least this "Electronic
Noise Quiz" from the August 1962 edition of Popular Electronics
won't affect your GPA. Sometimes PE's quiz illustrations are kind of hard to
interpret, but this one does a pretty good job (except item 'E', but I'm not
telling what it is since nobody helped me). You will need a fairly diverse
background in consumer type electronics to do well, and having a few gray hairs
will probably help as well. Good luck. BTW, my score was a somewhat embarrassing
80%...
 This "Recent Developments in Electronics"
from a 1960 issue of Electronics World had a lot of
antenna news that included a retarded surface wave antenna with high gain and
low silhouette for use in airborne early warning radar as well as ground based and
shipboard radar, a pair of 60-foot tropospheric scatter antennas that are specially
mounted at opposite ends of a 180-mile long section of the Gulf of Mexico, and a
104-foot-long rotating 50-ton radar antenna used for the SAGE early warning system.
Also reported was Westinghouse Electric's airborne Stratovision for broadcasting
educational television programming to rural areas out of reach of existing
towers...
 The 1950s was a time when futurists were predicting
that
domestic robots would be common place items in households. By the turn of
the century, mankind, freed from the drudgery of manual labor, would have plenty
of time for recreating, resting, and sitting around brainstorming the next big
thing. Here it is 12 years into the new century and at the most, a fraction of a
percent of the population even has a Vroom robotic floor vacuum - and it looks
nothing like a human. This comic from the November 1957 Popular Electronics
exemplifies the visions of the last century. Now, maybe by the end of the 21st
century we'll finally be there...
 Sometime around 1980, while stationed at
Robins AFB, Georgia, I finally succumbed to the peer pressure of other more sophisticated
audiophiles in the barracks and bought a "real" stereo. Unlike my roommate who had
a full compliment of rack-mounted gear, my meager enlisted military pay only allowed
for a mid-grade instrument. The solution was a
Sansui TA-300 Integrated Tuner Amplifier. It put out a whopping 30 watts per
channel, but unlike my existing radio (a Readers Digest 800-XR), those 30 watts
were nearly distortion free when driving good speakers. Having only the pathetic
5 W speakers that came with the 800-XR, I designed a set of speakers rated for
60 W, and built the enclosures myself in the base woodshop. Unfortunately, in
preparation for a household move about 20 years ago, I sold the Sansui and the
speakers...
 This is a nice short article covering the
calculation of inductances for coils wound on cores and wire sizes. It appeared
in a 1932 issue of Short Wave Craft, but of course inductance has not changed
since then so it is still relevant. The author recognized that standard formulas,
although concise and accurate, are sometimes difficult to work with when calculations
for a large number of values is needed for a particular circuit design. To address
the situation, he presents a handy nomograph, chart, and a table of typical values.
He also introduces a rarely seen term "Nagaoka's correction factor*" for skin
effect. A smartphone app, a spreadsheet, or a desktop computer program would be
used today to calculate inductance...
 Since 2000, 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. The
jury is out on whether or not this type of mental challenge helps keep your gray
matter from atrophying in old age, but it certainly helps maintain your
vocabulary and cognitive skills at all ages. A database of thousands of words
has been 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, if you don't already know, might
surprise you...
 Lots of
RF transmission cable parameter charts are available on the Internet, but what
sets this one apart is that is has entries for some of the popular 300 Ω
twin-lead cables of the rooftop television antenna era. It appeared in a 1956 issue
of Radio & Television News magazine. Mentioned in the article is the
reason most TV lead-in cable was colored brown was to help keep the sun's ultraviolet
rays from penetrating and deteriorating the plastic. Author Robert Gary claims silver
coloring was also used to reflect the UV, but I don't recall ever seeing silver
twin-lead - maybe it was a regional thing like for in the southwest. At the time,
μμfd (micro-microfarad) was commonly used rather than pF (picofarad). He also mentions
the G-Line transmission cable used by many of the...
 Exploiting the electronic nature of living
organisms through contrived application and manipulation of electric currents has
been a goal of researchers (and quacks) ever since Luigi Galvani first discovered
that connecting a battery lead to a frog's leg would cause it to kick.
Psychogavanic reflex (PGR) is the technical term for the science. Once it
was determined that all forms of fauna would respond to electrical stimulation,
it wasn't long before the same sort of treatment was applied to all forms of
flora. Many people (not me, for the record*) believe that talking to plants can
influence their health and growth, so why not - so goes the reasoning - try
electric currents as well. We all know from spy, war, sci-fi, and horror movies
that under the right conditions...
 This is yet another example of humorous
- and clever - poetry written by Hams from back in the 1940s... November 1942,
to be exact. It, along with "''Somewhere in Australia," appeared in the ARRL
magazine QST. As alluded to in the title, "Ravin," it is a play on
Edgar Allen Poe's famous "The Raven" poem. A editorial note added, "QST's mail
these days is laden with [aspiring poets'] efforts. Of these, many are, of
course, quite devoid of merit; others, while readable, are unavailable simply
because of space limitations. Yet so strong a flood of contributions must
indicate at least a partially equivalent strength of reader interest...
 A few months ago, one of America's big-city
mayors made the proclamation, "We're not going to make America great again. It was
never that great." There has been a big push in the last decade to not only erase
the
significant accomplishments and sacrifices of America's and Western Europe's
past, but to vilify those people and institutions that make up that past.
Purging the records and rewriting history is a tried and true method of assuring
few have easy access to archival material documenting the accomplishments of the
nation's past. Along with desiring to provide useful and interesting material to
people seeking technical and historical information, my motivation...
 This
subscription renewal for Radio-Electronics magazine was tucked
inside one of the group of 1969 issues I bought on eBay. It's not a big deal,
but is always interesting to see how the companies communicated with customers
in the day. Note that the mailing address for Radio-Electronics is simply
Boulder, Colorado, with no street address given - all the mailmen must have
known where they were. The cost was $12 per year...
 This line from the Basic Navy Training
Courses is very important when considering electrical machines: Many electrical
devices and machines operate on the principle of "transformer
action." They in fact are not transformers - but the theory of their operation
is best explained by considering them as if they were transformers. It is part of
chapter 21, entitled, "Some Electrical Machines - Transformer Action," which provides
a simple introduction to induction motors and generators, regulators, frequency
converters, and synchros. If you are a newcomer to the field of electricity
and/or electronics, or if you just want to brush up on old knowledge to be
conversant at office parties, this is a great short read. A quiz is provided at
the end...
 After many years of reading
Mac's Service Shop sagas, a persistent theme seems to be Barney's refusing
to refer to equipment schematics while troubleshooting, thereby often wasting
valuable time. According to business owner and electronics sage Mac McGregor,
assuming that what is typical for most sets will apply to all sets can and does
create a fertile environment for frustration - and profit loss. Mac's advice to
check "simple things first," has always been my troubleshooting philosophy -
maybe because identifying the "hard things" has nearly been my undoing many
times when the trouble is not simple. One of first things I do is check
switches, connectors, and user-accessible potentiometers for proper operation
(when potentially responsible for the problem, of course). I've written many
times about how often a dirty connector is the culprit...
 This week's crossword puzzle will keep you
busy for a while. Since 2000, 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. The jury
is out on whether or not this type of mental challenge helps keep your gray matter
from atrophying in old age, but it certainly helps maintain your vocabulary and
cognitive skills at all ages. A database of thousands of words has been 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...
 Here are a few
tech-themed comics from the April 1967 edition of Popular Electronics
magazine depicting the perception of techies during the era. As mentioned
before, stereo equipment was a big deal in the era, back before most people
listened to music through ear buds attached to smartphones. When in the USAF in
the early 1980s, a sure sign of hipness was to have 19" equipment rack in your
barracks room, stuffed full with a reel-to-reel tape deck, a high end AM/FM
receiver ("tuner," to the audiophile), power amplifier that could deliver at
least 200 W per channel, a dual cassette deck, turntable (referring to it as a
"phonograph" revealed your squareness). Of course no self-respecting stereo
aficionado would be caught dead with an 8-track tape deck in the rack... |
