|
 Fixed-value resistors are among the
simplest-looking components in electronics, but their development reflects
nearly the entire history of electrical science, telecommunications, electric
lighting, industrial power, radio, military electronics, printed circuits,
hybrid microelectronics, and surface-mount manufacturing. Partly out of
curiosity of how extensive, comprehensive, and accurate an AI-generated report
on topics of science and engineering, I instructed ChatGPT to generate the
following thesis titled
History of Fixed-Value Resistor Electronic Components. Most useful AI
interactions, I have found, require more than one input...
 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 magazine. 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...
 Comics in modern magazines are a rather
rare phenomenon for some reason, but they were fairly regular features up until
a couple decades ago. This set of
comics from the July 1963 edition of Popular Electronics magazine deals with
high fidelity (Hi-Fi) stereo equipment, which was considered somewhat exotic and
high-end for many people's budgets in the day. Inexplicably (not), that is about
the time that increases in hearing losses among younger people were first being
noticed in audiograms. I listened to my share of loud music beginning in the
late 1960s, and operated many model airplane engines and lawnmower type engines
my whole life, and still, at 68 years...
 "Ground is ground the world around." That's a saying that I
have often heard Ham radio operators say aloud and in writing. In a general sense,
it's true, but on a local level grounds can vary widely from location to location,
even within a few hundred feet. It is true both for direct current and low frequencies
and for frequencies in to the GHz regions. It has to do with the conductivity of
the soil and/or rock in the area as well as the amount of moisture and other elements
in the ground. Antenna guys like to run conductive (usually copper) "radials" out
from the mounting pole or tower in order to create a sufficient local reference
ground, and electric power distribution engineers often need to salt...
 ConductRF is continually innovating and
developing advanced solutions for RF cable assembly and various RF through millimeterwave
interconnect requirements. ConductRF offers both its own brand of high-quality
RF cable and connector components, along with a curated selection from leading
manufacturers, enabling engineers to optimize performance while maintaining
supply chain flexibility. Please be sure to visit their
Updates section at the
ConductRF Blog
and sign up for their monthly news releases.
 Other than vaguely recognizing the name,
do Millennials know who
Mickey Mantel was? Maybe hard-core Yankees fans of all ages still
know. My having been born in 1958, the kids in my neighborhood watched "The Mick"
playing on TV, witnessing real-time some of his final 536 career home runs being
hit. When this two-page Westinghouse advertisement appeared in a 1954 issue of Radio &
Television News magazine, he was only beginning in his forth season in Major League
Baseball (MLB), which ran through 1968. The promotion was for a contest where servicemen
who bought Westinghouse vacuum tubes submitted a witty response for the comic showing
a housewife asked...
 Do you know how engineering whipping boy
Dilbert
came to be called by that name? Per Scott Adams, while working at Pacific Bell he
ran an informal name-the-comic-strip-engineer contest from his cubicle. A guy named
Mike Goodwin suggested Dilbert. "I ended the contest immediately and declared Mike
the winner," says Adams. It sounded perfect. Years after the comic strip had become
syndicated, Mike commented that he believes the name idea might have come from seeing
his father's old WWII aviator comics with "Dilbert the Pilot." DtP was a screw-up,
invented by Navy artist Robert Osborn, whose purpose in life was to illustrate the
wrong way of doing things so that...
 My new
Online RF Systems
Cascade Calculator handles up to eight stages. All input stage parameters,
Gain, Noise Figure, OIP2, OIP3, and OP1dB, are limited to ±200. P[input] has a lower
limit of -174 dBm (GTB in 1 Hz bandwidth). IP2, IP3, and P1dB values are
all reference to the stage output. AI provided most of the PHP code after many iterations
of instructions, but it is amazing what it came up with - and with very few lines
of code...
 Those of us who have been around for six
or more decades have lived through two evolutions of video display types - raster
scanned
cathode ray tubes (CRTs) and digitally pixelated light-emitting
diode (LED) and liquid crystal (LCD) displays. Unlike with the latter display types
that improved in color depth, picture resolution and display size, the former had
effectively a fixed resolution of horizontal lines (525 vertical steps - only 484
visible, actually, due to blanking). That meant for CRTs, designers needed to find
ways to make images appear in-focus while also looking continuous on larger screens.
Doing so involved cleverly adjusting the size and spacing of fluorescent...
 Multiple path transmission, diffraction
around obstacles, absorption by foliage, and reflection from moving objects have
always been challenges to the wireless system designer and/or user. Whether it concerns
communications between a WiFi router and a notebook computer, a cellphone and a
tower, an FM radio with a broadcast station, or deep space probe with an earth station,
all of the aforementioned mechanisms must be dealt with to some degree. Although
in a different way, even
transmissions within a waveguide or coaxial cable deal with those
same issues - reflections and the resulting standing waves have the same effect
as multipath in terms of vectorially additive versions of the same...
 Those of you who are not particularly interested
in vintage electronic equipment will please indulge those of us who
are. I post these articles occasionally to remind people of from whence we have
come. Whether you are an amateur radio operator or just a cellphone user, appreciation
is due to the pioneers who took the metaphorical arrows for us so that we may enjoy
the micro-size, low cost, high quality communications available today. The full-height
equipment racks in the photos were standard fare in the 1930s for long distance
(DX) shortwave operators - often only for CW (Morse code). "User serviceable parts
inside' was the rule rather than the exception. As much as I like waxing...
 Anritsu announced the launch of its new
Tensor Vector Network Analyzer (VNA) at IMS 2026. The Tensor VNA represents
a major advancement in RF and microwave network analysis, delivering modern, scalable
architecture designed to support the most complete and demanding measurements like
amplifiers, filters, frequency convertors, and other advanced VNA measurements.
Tensor VNA sets a new benchmark in vector network analysis with its revolutionary
source-per-port architecture, integrated AI intelligence, and exceptional power
handling. Engineered to meet the evolving requirements for aerospace and defense,
semiconductor, active and passive device measurements, signal integrity, research
and development, and millimeter wave / waveguide...
 Here is a reprint of an article I had published
in Wireless Design & Development magazine in 1995. Some of the references
are a bit dated, but the info is all still very useful. Waypoint Software is now
RF Cafe, and TxRx Designer is now Shareware by the name of RF Workbench. With
the advent of high speed personal computers, a very insightful graphical method
of determining inband mixer spurious products has been largely forgotten. The
Spur Web™
(my name trademark, but used widely w/o attribution) chart rapidly identifies both
inband and out-of-band spurs, affording a pictorial view of where conversion system
frequencies lie with respect to all spur products. A comparison...
 The neighborhood where I grew up in the
1960s and 1970s was about 25 to 30 miles from the "big three" network television
broadcast stations (ABC, CBS, NBC) in Baltimore and Washington, D.C. That is considered
a fairly long distance in the over-the-air TV realm. Knowing what I know now, I
am somewhat surprised that those in our area were able to receive programs as well
as we did when all the homes I recall had just a single, standard multi-element
antenna on the roof. If anyone had stacked, phased array setups like this
Finco Co-Lateral TV Antenna installed, I certainly do not remember
any. Most of the antennas in Holly Hill Harbor and the surrounding communities did
not even have an antenna rotator, yet evidently were pulling in signals satisfactorily
- and without needing to be mounted on a tall...
 In this Radio & Television News
magazine article, author Jack Gallagher derives a formula for the number of turns
of wire to wind on a form of given dimensions for a parallel
constant-resistance network. He argues that although commonly
used formulas like that of Wheeler provide the number of turns needed to achieve
a desired value of inductance, it does not predict the size of cross-sectional shape
of a coil form that results in an optimal configuration. His work applies to audio
frequency divider networks like those used for speakers to steer specific frequency
ranges to a woofer, midrange, and tweeter trio; hence the need for "constant resistance"
(e.g., for standard 8 Ω or 16 Ω speakers)...
 Satellite direct-to-device (D2D) networks
represent the next frontier in mobile connectivity, promising to eliminate dead
zones by linking ordinary cellphones directly to orbiting satellites. Companies
like SpaceX with its Starlink system, AST SpaceMobile, and others are racing to
deploy constellations that can serve standard smartphones without specialized hardware.
The technology relies on large phased-array antennas in space, advanced beamforming,
and new spectrum-sharing arrangements with terrestrial carriers. Proponents argue
D2D will bring emergency communications and basic connectivity to remote areas worldwide.
Critics raise serious concerns...
 During my electronics technician days at
the Westinghouse Electric Company's Oceanic Division in Annapolis,
Maryland, I spent the first couple years building printed circuit boards, wiring
harnesses, and system-level assemblies for U.S. Navy sonar systems. We had some
really slick stuff like towed vehicles with transducer arrays along the sides, nose
cones for smart torpedoes, flow sensors, proximity fuse elements, etc. Exposure
to all that, and the super-smart people that designed it, fuelled my desire to go
to the trouble of earning an engineering degree. One of my tasks for a while was
to build the transducer arrays, which entailed building the hundreds of tiny transducer
elements. One of the phased...
 With the extreme volatility of today's
stock market, I thought this might be a good time to re-post an article I wrote
back in 2012 entitled "Arbitrage
via Microwaves." The ±200 point daily swings of a mere 8 years ago seem
paltry compared to ±1,000 of late. The original page on the IEEE Spectrum
magazine website is dead now, so I had to change the hyperlink to an archived page
on The Wayback Machine - a
great resource for you to remember if you ever need to retrieve a webpage that has
been disappeared [sic]. My piece begins: "If you have wondered why the world's
stock markets behave the way they do, why the DJIA falls 150 points on one day on
news of Greece leaving the euro...
 You wouldn't know it from the lineup
of
Crosley Corporation radios and turntables appearing in department
stores, but the company also manufactures dishwashers, ranges and freezers, clothes
washers and dryers, and air conditioners. That is still a small chunk of what Crosley,
based in Cincinnati, Ohio, made back in the middle of the last century, including
cars and trucks, a small private airplane (the Moonbeam), television sets and even
had a television broadcast station, as well as other items that were part of the
mainstream of American life. Take a look at their About Crosley webpage for more
insight. Amazingly, along with the extensive line of retro radios and turntables,
they still also...
 What got my attention in this 1955 Radio &
Television News magazine article was the "picture-on-the-wall" concept being predicted by General Electric
(G-E) engineers, based on its light-amplifying phosphor invention. Determining exactly
how the device works is difficult based on the information given, but it appears
that the ultraviolet light source which is being amplified is projected onto the
surface of the amplifying substrate, and then an exact duplicate of the image is
reemitted toward the viewer. The conceptual drawing of a large screen hanging on
the wall is most likely driven by a UV projector located near the ceiling, akin
to how the large screen home theaters popular in the early...
|
Loading history...
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 November 1965 issue of Electronics World
magazine featured a set of articles reporting on the fledgling semiconductor industry.
The title of this one, "Integrated
Circuits: What's Available?" would require volumes to print today, but at the
time the selection could be summed up with a relatively small amount of paper and
ink. Author Donald Lancaster exuberantly and correctly predicted some of the many
products and uses that miniaturization and capability the burgeoning technology
would enable. Among them he cites desk[top] computers priced lower than mechanical
adding machines, picture-on-the-wall TV, truly portable communications...
 As with the article in this month's issue
of Radio-Craft magazine (December 1937), the reference to a 200th anniversary
is understated by 78 years for 2015.
Luigi Galvani was sort of the Benjamin Franklin of biology in that just as Franklin
demonstrated that lightning was a form of electricity, Galvani showed that signals
sent from the brains to the appendages of animals were electrical in nature. In
my high school days in the 1970s, we duplicated his experiment by making deceased
frogs' legs twitch when motivated by a D cell. Today, such an exercise would likely
be met with demonstrations by animal rights people (whose lives, BTW, have probably
in some way...
 This is your custom made
Electronics Themed crossword puzzle for December 11th, 2022. All RF Cafe
crossword puzzles are custom made by me, Kirt Blattenberger, and have only words
and clues related to electronics, electricity, radio, radar, 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...
 This set of
electronics-themed comics from a 1956 issue of Radio-Electronics magazine hits
on a variety of topics that were big in the day. Computers were coming into the
public realm rather than just being a sci-fi wonder. Home personal computers were
still a couple decades away, but mainframes were being imposed on the public through
accounting and merchandising venues, rather than just curiosities of research laboratories.
The "large screen" 27" television cabinet was necessarily deep enough to park a
car in because cathode ray tubes (CRT's) were used, not flat screen plasma, LCD,
or LED displays. Look closely at the captionless hospital scene to see...
 An avid philatelist in my teens and twenties,
I collected, along with other stamp varieties, many First Day Covers, which are
specially designed envelopes bearing a new stamp design and are postmarked in the
city, on the day which they are formally released. Last night I finally got around
to digging out my
First Day Cover commemorating The International Geophysical Year (IGY), released
on May 31, 1957, in Chicago, Illinois. The IGY (actually IGYaaH - IG year-and-a-half)
began on July 1, 1957 and ran through December 31, 1958. It was the dawn of space
/ high altitude flight and there was a great need to learn as much as possible about
the physics of the...
 Just as optimizing the transmission path
between an RF transmitter and receiver helps guarantee the best possible fidelity
in receiving an exact copy of the transmitted signal, so, too, does
optimizing the signal path for an audio signal help guarantee a faithful replicate
of the original sound. This article from the March 1959 edition of Popular Electronics
magazine is a primer on the topic of understanding how the human ear perceives sound,
and how to best facilitate a good match between the speaker and the ear drum. In
the era, home-base hi-fi equipment was a big deal, as was building out listening
areas for optimal performance. Room floor, wall and ceiling materials and...
 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...
 The Radio Service Data Sheets that were
published in Radio-Craft magazine usually seem to have more information
included than those published in other magazines, at least in the same era (1940-ish).
It might have to do with how much material is provided by the manufacturer rather
than a decision by the magazine editors. Either way, here are the schematics, chassis
layout, and service info for the
Lafayette Model B-100 through B-103. As with most radios built in the era, the
woodwork and artistic design of the cabinet are exquisite. There are still people
searching for such data, but fortunately the Internet is making it much easier to
locate. None of the three...
 Here you are -
portable satellite communications in the mid 1960s per this photo from Electronics
World magazine. It has a unique "cloverleaf" ganged parabolic antenna array
with phasing control. Today, we have "manpack" type systems which use compact antennas
that can be quickly assembled and disassembled in any environment, along with receivers
that have sensitivities much greater than the type shown here. As the name implies,
they are transportable in backpack form. Software-defined radio (SDR) technology
facilitates programmable modulation and frequency band operation. The Mark V AN/TSC-54
Satellite Communications Link...
 Some things never change, as the old saying
goes. One of those things is adopting a good
preventive maintenance plan for your car or truck. Oil, transmission, and
cooling system fluid level and condition are tasks even the least mechanically
inclined amongst us can do ourselves. So is inspecting and replacing if
necessary intake and cabin air filters. Checking the condition of brakes,
suspension parts, body panel integrity (corrosion and proper fastening), and
other easily inspected components my not be the purview of most motorists, but
friends and/or professional servicemen can take care of that for you.
Admittedly, there is a large amount of not just unserviceable...
 Here is a batch of
electronics-themed comics that appeared in the July 1948 edition of Radio
News magazine. The comic on page 122 would probably elicit cries of racism
or hate speech these days, even though there is nothing racist about it. Note how
prescient the comic on page 140 was. It shows how long futurists have ben contemplating
the technologies that have become or are becoming common place today - of course
many of them were promised to us by the end of the last century by the like of Popular
Mechanics, Mechanix Illustrated, et al. The one that appeared on page 175 is pretty
clever. Such a malady is rarely encountered with today's radios, but...
 Have you ever heard of a "nuvistor?"
It didn't seem familiar to me right away until after I looked it up. Nuvistors were
high mu (high gain) tubes, manufactured originally by RCA, used in sensitive receiver
front ends. They came in about a dozen different varieties. This particular NASA-136
receiver for satellite reception uses a 6CW4 triode. Per Wikipedia, "Most nuvistors
are basically thimble-shaped, but somewhat smaller than a thimble, and much smaller
than conventional tubes of the day. Triodes and a few tetrodes were made. The tube
is made entirely of metal and ceramic. Making nuvistors requires special equipment,
since there is no intubation to pump gases...
 Gimmick or brainstorm? I'd says the
Jerrold Magic Carpet Antenna is a little bit of both. Undeniably, it is a good
way to conceal a full-size antenna with the general characteristics of multi-element
broadband structure. The downside is that it is fixed in position and any directionality
will favor some stations while shunning others. Its installation inside removes
weather concerns - snow, ice, and wind - which is a major advantage. I have never
seen one, but the illustration seems to show that the antenna elements are integrated
into a fabric sheet (hence the "carpet" part of the name), so its geometry is fixed
and should be consistent as long as the installer takes care to not distort it...
 This Radio Service Data Sheet for the
General Electric Model HJ-1205 floor console model vacuum tube radio came from
the June 1940 edition of Radio-Craft magazine, published by Hugo Gernsback.
Console type floor model radios had plenty of space for large speakers, more effective
built-in antennas (usually mounted around the perimeter of the back of the cabinet),
and more convenient tuning and sound adjustment controls. The HJ-1205 featured "feathertouch"
pushbuttons. Some of the early pushbutton tuning mechanisms took a pretty heavy
finger to manipulate. I post these for the sake of hobbyists and historians searching
for information on...
 "Merry Christmas!" Here is a 2-page advertisement
run by the
E.F. Johnson company in the December 1953 issue of the ARRL's QST
magazine. E.F. Johnson was a major player in amateur radio, and then later
Citizens Band (CB) radio. They also manufactured a large array of point-to-point
commercial radio products (Land Mobile Radio Service, LMRS, and Commercial Mobile
Radio Service, CMRS), as well a large line of RF connectors and adapters. The wireless
automatic meter reading (AMR) industry was pretty much born out of a very capable
group of engineers, technicians, assembly workers, and managers at E.F. Johnson's
facility in Waseca... |
