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A Radioman's Wife Puts in a Good Word
In the days before people were so easily
offended by light-hearted poking, it was not uncommon to find magazine articles
written by the wives of hobbyist husbands lamenting the habits and proclivities
of their matrimonial mates. Over the years I have read many such treatises in model
and full-scale airplane, electronics, and Ham radio publications. As with "A
Radioman's Wife Puts in a Good Word" from a 1951 issue of Radio-Electronics,
they typically start by expressing frustration of having lost their once-doting
husbands to alternative loves in the form of hobbies (I once saw a boat named "The
Other Woman"). Determined to win back the devotion of their sweethearts, they make
a sincere attempt to learn about and be part of whatever hobby or hobbies is/are
the cause of abandonment of wife and children. It usually doesn't take long for
Friend Wife, as Popular Electronics' Carl Kohler addresses his better half, to decide
that try as she may, engendering a sufficient...
Gray Market Electronics - Reaping What We've Sown
Gray market electronics components have been
a problem for a long time. An extensive article appeared recently in EE Times
reporting on a case based on a small operation in south Florida that was importing
and re-selling counterfeit parts to military, aerospace, medical, and other product
manufacturers. The Feds charged them "with conspiracy, trafficking in counterfeit
goods and mail fraud for knowingly importing more than 3,200 shipments of suspected
or confirmed counterfeit semiconductors into the United States, marketing some of
the products as "military grade" and selling them to customers that included the
U.S. Navy and defense contractors." The good news might be that this particular
scam operation was caught and stopped, but the bad news is, according to the story,
that many more are never prosecuted...
Lamp Bulb Resistors
Most people who have been in the electronics
world for a while know that neon light bulbs* used to be commonly employed as a
"pert-near" voltage regulator reference of between 55 and 65 volts, depending on
the type. The familiar NE-2 has a turn-on voltage of 65 Vac (90 Vdc),
for instance, and the voltage across the terminals remains there with little change
regardless of the current through the bulb - a lot like a Zener diode. Neon bulbs
are also used as non-invasive RF power detectors. Most people probably do not know,
however, that incandescent bulbs also have properties that make them useful for
purposes other than just lighting up a dark space.
Incandescent light bulbs have been used successfully for voltage regulation
and RF power measurement. They have also been used as dummy loads for transmitters.
John Parchman details some of these uses...
The Broadcasting Goose
"Are
we killing the broadcasting goose, layer of many golden eggs?" Dr. Lee de Forest
asked in his inaugural address, upon his election to the presidency of the Institute
of Radio Engineers. So went the opening editorial in a 1930 edition of Radio
News magazine. It was directed at the question of whether excessive, "gratuitous"
advertising was going to be so offensive to listeners that they would turn off the
set and go back to their former silent worlds. Remember that many, if not most,
households, and certainly not automobiles, even had radios at the time. Building
an audience was essential to nurturing the new phenomenon of radio, and to saturate
the listeners with commercials would surely doom the medium. Dr. de Forest would
be truly depressed if he could see the commercial broadcast landscape today with
it consisting of 15-20% advertising content and much of the rest filled with political...
Smellevision Now Here!
We all know that for the most part television
stinks. Back in 1951 when this article appeared in Radio-Electronics magazine,
the technology was very new and it was considered a miracle not to be wasted on
inane programming. Newscasts actually presented news and not opinion, movies and
sitcoms cast the nuclear family, law enforcement, the military, religion, and patriotism
in a positive light rather than as the purveyors of evil in the world. By the end
of the 1960s to early 1970s a lot of that had changed. Political and social agendas
weaseled their way into nearly all programming to the extent that terms like "boob
tube" and even, yes, "smellivision,"
became common monikers for television. The form of smellivision presented in this
article was granted patent (US2540144A) protection in 1951 under the title, Television
with scent effects..."
Thanks to Brad B. for Many New W-J Tech Notes
RF Cafe visitor Brad B. just provided
the following
Watkins-Johnson Tech Notes for the collection: v5-3, v5-4, v5-5, v5-6, v6-2,
v6-3, v6-4, v6-5, v6-6, v8-1, v8-4, v9-1, v9-2, v9-3, v9-4, v9-5, v10-2, v10-5,
v10-6. They run the gamut from Solid State Limiting Amplifiers and Antenna Polarizations
to Digital Signal Processing for Multichannel Receiving Systems. Many old-timers
consider the W-J Tech Notes to be some of the best sources of circuit and systems
design guides ever written, especially for military, defense, and aerospace applications.
Carl & Jerry: Feedback
In this episode of John T. Frye's "Carl &
Jerry" series, the intrepid pair of teenage electronics hobbyists and Ham radio
operators are experimenting with an audio amplifier rig that uses a parabolic dish
for concentrating sound waves at a focal point where they have a microphone mounted.
Aside from picking up bird noises and a neighbor lady scolding her husband for not
properly washing the windows during a round of Spring cleaning, Carl imposes upon
Jerry for a lesson in
feedback techniques - both positive and negative - and the reasons one is preferred
over the other. The story winds up with a clever double entendre comment referring
to osculation...'
Radio & Science Crossword Puzzle for May 24
Beginning in the year 2000 and running through
today, May 24, 2020, I have been creating weekly custom
technology-themed
crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors
who are fellow cruciverbalists. 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, familiar company names 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.
Understanding Mechanical Filters
I'm not sure how much
mechanical filters are used in circuit design these days due to their somewhat
large size and complexity. They typically exhibit a high "Q" with a relatively flat
passband (with some ripple) and very sharp cutoff in the skirts, and the insertion
loss is low compared to lumped element equivalents (for comparative out-of-band
cutoff). Operational frequencies were limited to a few hundred kilohertz, so they
are useful only at intermediate and baseband frequencies. This article, appeared
in a 1953 issue of Radio-Electronics magazine, describes the basics of mechanical
filter design and construction. Mechanical filters from aircraft radio manufacturer
Collins and other can be found on eBay...
Resistance and Capacitance Measurements with the V.T.V.M.
Prior to the advent of
FET-input multimeters, obtaining a very high input impedance meter required
the use of a vacuum tube circuit that used a buffer stage to isolate the measured
signal from the loading effects of the meter movement. As most people reading this
article already know, the voltage value indicated by a non-buffered meter can be
greatly affected by the meter's loading of the device under test (DUT) if the meter's
impedance is not many times greater than the DUT's impedance. The voltmeter is used
in parallel with the circuit under test, so for example if the impedance of the
DUT is 100 kΩ and the meter's impedance is also 100 kΩ, the meter will
display a value as if the DUT itself had only a 50 kΩ impedance, which represents
a huge error. The problem was that VTVMs were relatively expensive and beyond the
budget of most amateurs...
Mac's Service Shop: Chisel Blunters
The dichotomy between the customer who is
worried about the service
shop owner ripping him off and the service shop owner who is worried about the
customer ripping him off is an old one. Given how even normally honest people allow
themselves a "white lie" here and there to consummate a business deal or pacify
the whims of an acquaintance, it is understandable how such suspicions come to be.
In this 1958 issue of Radio & TV News, Mac McGregor and trusty sidekick
Barney Jameson discuss how to handle customers who imply the desire for or outright
request (even demand) special consideration on repair services and/or replacement
parts. The steadfast policy of Mac's Service Shop was "cash-only" - no exceptions.
In the days before readily available credit cards and cash advances from ATMs, it
was usually up to the business to extend and take the risk for credit. Often collecting
on the promised funds consumed significant effort and on occasion resulted in failure...
Radio-Electronics' Service Digest
Radio-Electronics magazines' "Service
Digest" column regularly reported on issues relevant to the electronics servicemen
who repaired radios, television sets, phonographs, recorders, and similar items
- often in the customers' homes. Then, as now, professionalism and courteous behavior
was often rewarded with word-of-mouth referrals to friends and relatives, resulting
in new business opportunities. An interesting topic also included was the need to
observe extreme caution when working around TV tubes (CRT's) not just because of
the lethally high voltages present, but because of the
danger of tube implosion and the resulting scattering of glass shards. An example
given is that due to standard atmospheric press of 14.7 lbs/in2 on the outside of
the evacuated volume, a 17-inch screen CRT tube supports a total pressure of 3,322
pounds, or 1.66 tons...
Semiconductor Heat Sink Design Chart
Not everybody with a high temperature semiconductor
application in need of heat dissipation has access to a thermal management program
with a database of available commercial
heat sinks and/or an ability to analyze a custom-made heat sink. This article
from a 1965 issue of Electronics World magazine contains simple equations,
a handy chart, and instructions on how to use them to figure out what kind of heat
sink you need for your project. At the time TO-8 and TO-3 metal cans were a couple
of the most common sizes for which a large variety of heatsinks were available...
Turret Booster Plug-In Amplifier
Here is a bit of "outside-the-box" thinking
from the vacuum tube era that is essentially a form of integrated circuit, where
the active and passive components are discrete rather than semiconductor. The concept
was to provide an assembly that could be plugged directly into a signal gain path
tube socket and provide an additional amount of amplification without needing to
do any special wiring or mounting of components to the chassis. The cost of $9.95
in 1951 is the equivalent of $99.99 in 2020 money, so it wasn't a cheap upgrade
- and that did not include the cost of an additional tube (about another $10 in
today's money). Given typical electronics service shop rates of just a couple bucks
per hour in the early 1950s, it might have been cheaper to pay the local guy to
do a customization of the circuit, and then tweak the operation of the entire television
or radio set. Having high voltage connections exposed outside the metal chassis
posed a serious electrocution potential (pun intended), and might have even made
the set more susceptible to interference...
Sweden Electronics Market
This is the
electronics market prediction for Sweden, circa 1966. It was part of a comprehensive
assessment by the editors of Electronics magazine of the state of commercial, military,
and consumer electronics at the end of 1965. Among Sweden's modern-day most recognizable
electronics and related manufacturers are Ericsson, Saab Group and Electrolux, in
existence in one form or another since 1965. Automotive company Volvo is also among
the largest manufacturers there, although not specifically of electronics. A number
of contemporary resources are available for obtaining reports (at a cost) on the
electronics industry in almost every country on Earth. Among them are "Consumer
Electronics in Sweden, August 2019" and "Electronics Industry in Sweden June 2019..."
