|
 You will love the irony at the end of this
Carl Kohler technodrama. It appeared in the June 1957 issue of Popular Electronics
magazine. I'm not going to spoil it by even hinting at the conclusion - only that
the story follows the familiar path of the dauntless husband-electronic-hobbyist
taking off on another of his somewhat hair-brained ideas, while "friend-wife" looks
on. Her self-restraint is tested, as usual - although she jabs with some uncharacteristically
harsh zingers this time. Have you noticed how men are expected to be self-deprecating
in situations in order to create humor? The technology here was considered bleed-edge
back in the day. BTW, I fed the husband's humor bait to AI and it came up with some
pretty good responses - like what had been expected by him. AI came up with
a long name for FUNIAC (clearly a play on names like UNIVAC and ENIAC)...
 "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 a 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
at that. 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. BTW, I'll bet "The Syncopated Clock" is another tune you've
heard many times but didn't know the title of it...
 Have you noticed how many wooden utility
poles are
bending under the load of communications cable weight they were never designed
to withstand? Some are ridiculously burdened - and it is not "engineered deflection"
for line tension changes. Power companies want to charge the communications companies
for pole and/or cross bar replacement and/or upgrading, but the FCC just ruled that
pole owners cannot charge the full cost of replacement. That financial deficit,
of course, gets passed on to electric power customers. You wonder why your monthly
bill has skyrocketed in the last few years? That is part of it - along with
us peoples subsidizing wind and solar generation, and paying for free Internet and
cellphones to half the population (including Illlegals). Do you fell violated? I
do.
 Radio-Craft magazine solicited inputs
from its readers for a series of "Radio
WittiQuiz" questions and answers related to radio and electronic, with a stipulation
being that there had to be some aspect of humor included. That meant that some of
the multiple choice answer options needed to be inane. For most of the questions,
the process of elimination is pretty easy, but a couple could cause some head scratching
- especially if you are not really sure of the answer. This group starts at number
28, so obviously preceding issues had questions 1 through 27. At some point I will
probably acquire them and post other Radio WittiQuizzes...
 Having never been a sports aficionado, I
have not spent much money or time at baseball, football, or soccer fields, hockey
rinks, bowling alleys, curling sheets, or basketball courts. When an air show comes
to town, however, I'm there. I'll stand in line for 45 minutes to tour the inside
of a DC-3, B-25, B-17, PBY-5, or just about anything that will admit me. What is
particularly enjoyable is inspecting the radio equipment racks and bays. The sight
and smell (I consider it an aroma) of the old UHF
and VHF sets, recording equipment, power supplies, generators, synchros, and the
associated wiring and connectors is something I never tire of experiencing. I always
imagine the men who operated and maintained everything doing their assigned duties
to keep those wonderful machines flying...
 The
Chronistor, which appeared in a 1958 issue of Popular Electronics magazine,
was a compact elapsed time indicator in the form of a common glass fuse. Powered
by electroplating, it requires roughly 1 mA of DC current to migrate metal
ions from anode to cathode via an electrolyte, resulting in visible cathode deposition
along a glass-printed hour scale. Standard options included 500, 1000, or 2500-hour
ranges, with specials (like a 1-year, 8760-hour version) from Bergen Laboratories.
The article outlines a basic series circuit for AC line operation, comprising a
half-wave rectifier, pilot lamp, and limiting resistor for the Chronostat...
 If
you have kids, you'll probably appreciate these two
comics that appeared in the May 1956 issue of Young Men • Hobbies • Aviation
• Careers magazine. Young Men was a fairly short-lived publication,
having existed for only a couple years around the 1956 timeframe. It was not affiliated
with the Academy of Model Aeronautics (AMA), which had its own series of magazines.
Howard McEntee, famed radio control pioneer, was on the staff, and Albert L.
Lewis was editor. Unlike the other aviation magazines of the day, Young Men covered
a broad range of activities and hobbies including model boating and cars, electronics,
chemistry, physics, school, amateur magic tricks, shooting, and more.
 "Google's parent Alphabet has reached a
definitive agreement to
acquire renewable energy developer Intersect Power for $4.75B, a transaction
that signals a structural transformation in how Silicon Valley intends to power
the AI era. By owning a power utility, Google can secure energy for its data centers
directly. This acquisition marks a departure from the industry's decade-long standard
of signing Power Purchase Agreements, where companies contract for energy from third-party
developers. Instead, Google is taking ownership of a 3.6-GW pipeline of late-stage
solar and wind projects, along with 3.1 GWh of battery storage..."
 Well... it was 50 years ago referenced to
the year this story was published in 1937. That makes it 138 years ago referenced
to 2025. The story's point is that half a century had passed already since the confirmation
of existence of electromagnetic waves as proposed by James Clerk Maxwell.
Heinrich Hertz's "Funken-Induktor" (spark inductor) and his "Knochenhauershen
Scheiben" (Karl-Wilhelm Knochenhauer's disk-type capacitors) were key to his ability
to generate, transmit, and receive EM energy. The work originated from attempts
to prove that light was a form of electromagnetic waves...
 Before the advent of companies like Sam's
Technical Publishing information packets, it was often impossible to obtain schematics
and service information from manufacturers unless you were a certified service shop
and/or dealership. In response to many inquiries from Radio-Craft magazine's
readers, publisher Hugo Gernsback queried the
top manufacturers of the day to determine their policies for distributing such
data. Unlike the last couple decades, procuring service information on commercial
products could be very time consuming, and often resulted in not even obtaining
what you needed. Thanks to the Internet being populated with schematics and mechanical
drawings for seemingly everything ever made, we no longer need to call or mail order
for information needed to repair your radio, television, cellphone, lawn mower,
toaster...
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes, and has quickly grown into a major designer and manufacturer with volume
production capacities. Our
WMC-0.5-20-30dB-S is a wideband 30 dB power coupler is a wideband 4-way
in-line power splitter covering 500 MHz to 18 GHz with very good return
loss, low insertion loss, and high isolation performance. The device covers military
bands C through J (upper UHF band, L, S, C, X, Ku, and K bands), delivering much
value to the program. No Worries with Werbel!...
 A lot of the guys I knew from my time in
the U.S. Air Force as an Air Traffic Control Radar Repairman (AFCS 303x1) went to
work for the government or defense contractors after separation. Many were retirees,
so they were (are) collecting military retirement pay on top of really good pay
doing field service work. At this point, probably most of those guys are now doubly-retired,
and collecting Social Security. They're living pretty well these days, probably
with nice homes paid off long ago. 1957, the year this solicitation for
field engineers appeared in Popular Electronics magazine, was right
at the end of the Korean War, and only a decade after World War II. A lot of
new equipment was designed and delivered...
 While working as an electronics technician
at the Oceanic Division of Westinghouse in Annapolis, MD, in the 1980s, I received
a vintage 1941 Crosley model 03CB console style radio for Christmas from Melanie.
It was in poor condition, having spent the previous few decades sitting in a barn
on the Eastern Shore of Maryland. Due to the era of manufacture, vacuum tubes rather
than transistors provided all the necessary amplification. One of the engineers
I worked for at Westinghouse (Mr. Jim Wilson, engineer extraordinaire)
was a Ham radio operator and had been from boyhood in Pittsburgh, PA. After learning
of my Crosley, he gave me his
B&K Dyna-Quik Model 650 tube tester for use in restoring the
radio. The Model 650 was a rather high-end portable tube...
 "Firefly Aerospace's Blue Ghost Mission
2 with the LuSEE-Night radio
telescope aboard will attempt to become the third successful mission to land
there. The moon's far side is the perfect place for such a telescope. The same RF
waves that carried images of Neil Armstrong setting foot on the lunar surface, Roger
Waters's voice, and hundreds of Ned Potter's space and science segments for the
U.S. broadcast networks CBS and ABC interfere with terrestrial radio telescopes.
If your goal is to detect the extremely faint and heavily redshifted signals of
neutral hydrogen from the cosmic Dark Ages, you just can't do it from Earth..."
 In the early days of television, what we
today refer to as cathode ray tubes were called
kinescopes. The kinescope on the receiving end displayed images generated
by a tube called an iconoscope on the transmission end. Kinescopes had round faces
onto which a rectangular picture was electronically drawn. Once manufacturing technology
evolved sufficiently, it became possible to make them rectangular in order to save
on material and to fit a larger picture in a smaller area. The real story as told
in this 1947 Radio News magazine article from my perspective is appreciating the
ingenuity of the manufacturing engineers for an ability to develop machines that
handle very complex operations. They were wonders of electromechanical manipulation.
Oh, and I learned a new word - "lehr"...
 This Radio Service Data Sheet for the
Sparton Model 40 6-Tube T.R.F. Automotive Receiver is an example
of the dozens of similar schematic and alignment instruction sheets that have been
posted on RF Cafe over the years. Obtaining technical information on most things,
even readily available items, prior to the Internet era was often very difficult
- if not impossible. Service centers had what was need provided by manufacturers
and distributors, but if you wanted to find a part number or service data on a refrigerator,
radio, lawn mower, garage door opener...
 Here is a great primer on the operation
of
traveling wave tubes (TWT). A controversy exists over who first invented the
TWT - Bell Telephone Labs' Dr. Rudolf Kompfner, or Andrei Haeff while at the Kellogg
Radiation Laboratory at Caltech. Regardless of its provenance, the device was a
major advancement in the development of high power microwaves. A TWT amplifies broadband
microwaves continuously: an electron gun emits a high-speed beam through a vacuum
tube, interacting with the weak input signal propagating along a helical slow-wave
structure. The helix slows the signal's phase velocity to sync...
 Take a break from workaday drudgery by trying
your hand at this week's
Amateur Radio crossword puzzle. Every word in the RF Cafe crossword
puzzle contains the usual collection of science, math, and engineering terms, and
also includes special words related to Amateur Radio (clues labeled with asterisk
*). There are no generic backfill words like many other puzzles give you, so you'll
never see a clue asking for the name of a movie star or a mountain on the Russia-China
border. You might, however, find someone or something in the otherwise excluded
list directly related to this puzzle's technology theme, such as Hedy Lamarr or
the Bikini Atoll, respectively. Enjoy.
 "Advanced threats lead to open architecture
approaches and new
analysis of electronic countermeasures. Over the past decade, preeminent countries
involved in major military conflicts mainly focused on asymmetrical warfare - surprise
attacks by small groups armed with modern, high-tech weaponry. During that same
period, however, near-peer adversaries began attaining impressive electronic warfare
(EW) capabilities. As a result, a plethora of new, dynamic threats flooded the EW
spectrum, pushing threat detection and analysis to keep pace. Large military forces
must now engage in ongoing..."
 Here are a couple more electronics-themed
comics from Electronics World magazine, good for winding down the week.
They appeared in the January 1963 issue. The page 86 comic reminds me of the professor
I had for solid state circuit design. He was supposedly the first person to successfully
use gallium arsenide (GaAs) as a semiconductor, although he also did pioneering
work with silicon. Anyway, Prof. Anderson would say he takes at least one "business"
trip each year to Portugal in order to search for higher quality raw semiconductor
material in sand on the beaches. He spoke Portuguese, BTW. The page 89 comic is
reminiscent of the pre-GPS days of navigation. Raise you hand if you ever drove
around utterly lost while looking for an off-the-beaten-path location...
 In the mid 1930s, hand-assembled products
were by far the rule rather than the exception for most products be they electronics,
furniture, appliances, automobiles, or toys. Many people lament - even curse - the
advent of machine automation in production, but the fact is for the vast majority
of things the consistency and quality of the finished component is typically much
greater. Toiling at the same task, in the same location, day after day, gets unbearable
very quickly for someone like me who likes to accomplish a particular job and then
move on to something new - even if "new" is defined as the same type of endeavor
but with different materials. There are many people, thankfully...
 At Parvoo University, amid relentless November
rain, H-3 dormmates Carl and Jerry pursue H-2's prank: a stolen bronze trophy plaque
hurled into a half-mile muddy stretch of river. Cold, turbid waters bar preclude
dives for a search; non-magnetic bronze defies current-day metal detectors. Jerry
repurposes his cousin's boat depth-finder as an
enhanced sonar, exploiting echo signatures. A motor rotates a neon tube across
a depth-calibrated dial; at zero, contacts trigger a 200-kc ultrasonic pulse from
the transducer in transmit (speaker) mode, flashing initial glow. Bottom echo reflects
to transducer in receive (microphone) mode, amplifying...
 The announcement and public demonstration
of Senatore Guglielmo Marconi's "death ray" device was the coming true of some of the worst fears
of science fiction aficionados. Application of these newly created centimeter wave
"beams" could roast the flesh of man or beast when generated with great enough power.
The diminutive wavelength not only would heat liquids, but also provided a means
of detecting and measuring energy reflected off of "targets" such as aircraft and
boats. It applications were endless. Although not called so, one of the article's
diagrams looks to be an example of a bistatic radar system. The early magnetron
implementation is quite different...
The Federal Communications Commission (FCC)
is looking for qualified applicants for
Field Agents in seven Enforcement
Bureau (EB) offices across the United States: Atlanta, GA; Boston, MA; Chicago,
IL; Dallas, TX; New Orleans, LA; New York, NY, and Portland, OR. Incumbents will
resolve Radio Frequency (RF) interference, educate users, and enforce regulations.
The GS levels for this position have been expanded to GS 7, opening the opportunity
for new college graduates. One year of work experience is not required for this
position. Closing date is March 2, 2026...
 If you are from a family of electronics
hobbyists and/or professionals, then there is a good chance your grandfather and
possibly even your father kept a handy-dandy list of common
circuit design formulas handy. Part 2 of the list appeared here in a 1930 issue
of Radio-Craft magazine. All the formulas on this page dealt primarily
with vacuum tubes, the schematics for which were presented in Part 1 of the series.
There are still lots of hobbyists who restore and/or modify vintage sets, so the
equations are still worth publishing. There was not an "app for that" back in those
days. Prior to a smartphone in every pocket, notes were pinned to a lab wall or
kept in a hand-written notebook...
 The name
Frank Conrad probably does not sound familiar to most people in
the electronics communications field today, but at one time he was the assistant
chief engineer to the Westinghouse Company. Back when voice radio (as opposed to
Morse code, aka CW) was being pioneered, Mr. Conrad was widely known for his efforts
in commissioning the country's first commercial broadcast installation - KDKA in
Pittsburgh, Pennsylvania. His arranging for live coverage of election night results
in 1920 is credited for launching a huge interest by consumers in purchasing radio
sets for their homes (Warren Harding beat James Cox that night, BTW). Toward the
end of his career, Conrad was active in helping develop...
|
 • FCC Gives
Amazon OK for 4,500 More Satellites
• China
Memory Producers Race to Exploit Shortage
• U.S.
Manufacturing Sector Returns to Growth
• ARRL
Student Coding Contest $25k Award
• Shielding
Electronics Supply Chain from Cyberthreats
• Fund Opens
Defence Contracts to UK Startups
 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.
 Wirewound inductors
(as most are) can be mysterious entities even when you
are familiar with their many interdependent physical and electrical properties. Because
of interwinding capacitance and a sometimes (when a large number
of turns are involved) rather significant series resistance, the equivalent circuit
model gets quite complex - literally in a mathematical sense. If you have the luxury
of staying far away from the self-resonant frequency (SRF)
of the coil, your component will behave very much like an ideal inductor, that is, XL
= 2πfL. This
article delves into what causes inductors to...
 I wonder why today's editions of the ARRL's
QST magazine does not have a column dedicated to the "YL" (Young Lady,
or female in general) contingent of the amateur radio realm? Ham radio, as most
- if not all - historically male-dominated hobbies has fairly significant outreach
efforts to try attracting women into activities. My Model Aviation magazine
has a monthly column written by a lady whose enthusiasm for model airplanes equals
that of most males - and she's funny to boot! - but it is not dedicated to female
modelers. If there is a girl or woman present at a competition, she is almost guaranteed
to receive coverage in the form of a photograph and/or mention in an article. Any
lack of other-than-male participation these days can only be attributed to a lesser
degree of interest by other than males. Could there really be a difference between
men and women (in general) after all?
 This story from a 1964 issue of Electronics
magazine is close to home - literally. Well, it was close to home at the time, anyway.
It reports on the work done by the
Electromagnetic Compatibility Analysis Center "...jutting out on a pier across
the broad Severn River from the United States Naval Academy at Annapolis." I grew
up in the 1960s and 70s just a few miles from there and distinctly recall seeing
all the antennas in the area, including the now decommissioned and removed acres-big
ELF submarine communications antenna farm. The Annapolis location, with its proximity
to Washington, D.C., was the home to many government and military installations
and defense contractors. It was an electromagnetic signal-rich environment...
 "The situation is one that is difficult,
if not wholly impossible to eradicate, because of all modern, 20th Century machine
age products, the radio receiver of today undergoes more violent and more radical
changes than almost any other single item we can think of." That was the lament
of electronics inventor, publisher, and industry visionary Hugo Gernsback in 1939!
He wrote in the February issue of Radio-Craft magazine of the practice
of
electronics component manufacturers vastly overproducing products and then,
when they are quickly obsoleted due to newer better ones entering the market space,
selling at below cost in hopes of recovering at least some of their investment.
For a man who otherwise encouraged, welcomed, and participated in the pushing forward
of technological frontiers, the attitude seem strangely at odds with his raison
d'être. "This 'dog eat dog' process has gone on ever since and will probably go
on for a long time to come." He had no idea ... or maybe he did...
 With even a modicum of familiarity with vacuum
tube terminology, you will fairly easily complete the custom crossword puzzle. This
Electron Tube Crossword Puzzle appeared in the May 1959 issue Electronics World,
which was the first sporting the name change from Radio & TV News. If you
are a hard-core crossword puzzle worker, then check out my weekly RF Cafe crossword puzzles
that draws upon a custom dictionary of thousands of engineering, science, chemistry,
and other technical words, along with words from current news items. Bon chance...
 When I saw the images in this "Electron
Shadows Map Force Fields" article from a 1949 issue of Radio-Electronics
magazine, the first thing I though of was how as kids back in the 1960s we would
hold magnets against the front of the television cathode ray tube (CRT) to see how
they distorted the picture. If I still had a CRT TV or computer monitor around,
I'd take some photos of it for the sake of those who have never seen what happens.
The difference between that and the images formed here is that the professionals
inserted the object of interest directly in the electron beam, between the cathode
and the fluorescent glass grid. As with the images in the article, magnets of various
shapes created unique responses. If you drag the magnet across the face of the CRT...
 Call me a hopeless
nostalgist when it comes to favored institutions I grew up with. I miss Pontiac
dealerships, Montgomery Ward, and Radio Shack stores. I miss Uncle Ben on the converted
rice package, and the indian squaw on the Land O'Lakes margarine package. I miss
trips to Blockbuster Video stores on Saturday to pick up a movie on VHS tape, and
walking through Toys R Us during the Christmas season. General Foods, Woolworth,
Eastern Airlines, Circuit City, Western Auto, Drug Fair, Read's Drug, Britt's Department
Stores, Lafayette Radio, A&P Grocery, Northern Reflections, Hechinger Home Improvement,
and Babbage's Software. All those and more were part of my growing up in the Annapolis,
Maryland area (with Parole Plaza being the prime shopping complex in the era). One
of the things I miss the most is the old
Sear, Roebuck and Co. stores - particularly the Craftsman tools and lawn and
garden sections. My parents bought just about everything from Sears, from us kids'
(five of us) school clothing, to household appliances, to lawn mowers, to furniture.
Sears' Open Hearth sofas, chairs, end tables, etc. (pretty sure we had this), were
nice wood and cloth designs which wore well and were fairly inexpensive. Of course
the Sears Wish Book and Montgomery Ward Christmas catalogs...
 This week's crossword puzzle for September
4th sports an
electrical engineering theme. 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, mathematics, chemistry, physics, and other technical
subjects. As always, this crossword contains no names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort unless it/he/she is
related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska
event in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
 Automotive ignition noise issues are rarely
experienced these days since not many people even listen to broadcast radio anymore,
and those that do tend to prefer FM stations. Portable music devices rule the world
both in and out of the car, with Bluetooth or phono jack connections to the dashboard
stereo making it easy to bring your own entertainment and use just the amplifier
portion of the box. Back before such conveniences existed, magneto, point, and condenser
ignition systems wreaked havoc with radio reception. AM was particularly vulnerable
because the noise was introduced inband and could not be readily filtered out. FM
helped matters, but even then it was not uncommon to detect a background crackle
in the audio that changed in frequency with the engine rotation speed; noise on
the DC distribution systems was the culprit. Electronic ignition systems went a
long way toward eradicating the problem. Nearly complete computerization of the
entire vehicle control and signaling installation has created a whole new source
of high frequency noise, but it usually is not noticeable to normal radio and digital
data devices. Ham radio operators still have to contend...
 Here is an interesting article that appeared
in a 1962 issue of Popular Electronics magazine discussing some of the
early electronic system developments that were based on
sensory elements found in nature. I'm a bit surprised and disappointed that
the author made the mistake of equating a bat's sound-based detection and navigation
system to radar rather than sonar. Yes, the principles of operation are the same
regarding transmitting a signal and then computing the distance based on the round-trip
time of the reflected signal, but there is a fundamental difference between radar
which uses radio (the 'ra' part of radar) signals and sonar which uses the sound
(the 'so' part of sonar) signals. I would bet that if I had the following December
or January edition of the magazine, I would find a letter to the editor...
 Whether or not this is a true story does
not matter- it is
both instructive and funny, especially if you catch the import of the closing
statement. Electronics magazines from the era of repairable entertainment electronics
devices like radios, television, and phonographs often carried stories of the woes
experienced by servicemen. Tales of in-home work were the most interesting, especially
when the homeowner tried to bilk the poor technician out of paying or accusing him
of purposely inflating the bill with unneeded parts and service charges. This 1941
issue of Radio News magazine is a good example of how frustrating the business
could be.
 This Crosley advertisement from a 1932 issue
of Radio-Craft magazine pitches two new models. Note the fancy wood cabinets which
made them higher-end radios. At the time, radio was the only form of "live" entertainment
in the home, so many radios offered shortwave bands as well as standard AM. The
$119.50 "Adventurer" model would cost $2,603 in 2022 money, per the BLS Inflation
Calculator! I am still looking in old electronics magazines for an ad featuring
my 1941 Crosley model 03CB console radio, but thus far with no luck. What makes
the model 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. In fact,
not long ago I found this brief news piece in a 1942 edition of Radio-Craft: "Crosley
Scraps 1943 Line for Military Radios" reporting on how Crosley was converting its
production line to support military needs...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
 I was born in the era of screw-in glass
fuses in household electric service panels. There was always a supply of replacements
in the cabinet above the stove. Sometime around 1978, prior to enlisting in the
USAF, I replaced the fuse panel with a Square D circuit breaker panel - a skill
learned through four years of electrical work. In the Air Force, I worked on a 1950s
era air traffic control radar system which consisted of many chassis assemblies
having fuse holders on their front panels. The racks themselves had a circuit breaker
panel, but it was a retrofit from sometime in the early 1970s. That was my introduction
into the wide variety of cylindrical glass fuses - high and low voltage, normal-,
slow- and fast-blow, time delay, etc. I learned of the reason why circuit designers
employed each type, and always used exact replacements when possible. Later, as
a circuit and systems design engineer myself, I always was careful to specify the
most
appropriate fuse type. This 1960 article in Radio-Electronics magazine
is a good primer on fuse handling...
 The
Instrument Landing Systems (ILS) has been around since the early 1930s, as made
apparent by this article in Short Wave Craft magazine. Frequencies, circuits,
and infrastructure equipment have evolved over the years, but fundamentally, landing
an aircraft (airplane, helicopter, dirigible) under 'blind' flying conditions has
not changed. Two precision beams - one in elevation and one in azimuth - broadcast
by ground-based installations are detected by airborne receivers and relative positions
are displayed for the pilot's use in navigation. ILS does not help the pilot fly
the aircraft; it only leads him to the runway threshold. In the past couple decades,
space-based Global Positioning System (GPS) equipment has increasingly been used
to replace ground-based microwave systems...
 In the pre-VHS era, companies were vying
to create and set standards for the
home-based video recording and playback industry. The same sort of scenario
played out over color television standards a decade earlier, and over B&W television
a couple decades before that. Such battles for dominance in emerging technologies
were not new, and continue into the current time. Various schemes for Electronic
Video Recording systems were being used by commercial media, but creating devices
affordable to Harry and Harriet Homeowner was a challenge. Betamax, produced by
Sony, hit the store shelves in 1975, then VHS a year later. A sort of 8-track vs.
compact cassette battle ensued, but VHS clearly emerged as the winner - followed
by DVD and Blu-ray. Also reported was the world's most expensive - and feature-filled
- color TV, built by Philips, that was "more computer than television," being able
to operate on eleven different modulation standards...
 Listen to this
story on the RF Cafe Podcast! Before there was the World Wide Web (aka the
Internet) and unlimited cellphone calling plans, personal communications over any
distance for most people was limited to local telephone calling areas. Long distance
calling rates were high enough to prevent casual calling of family, friends, and
businesses in the U.S. Overseas call rates were extremely prohibitive. The price
to "Reach out and touch someone" could set you back 10¢/minute or more. Even today,
an old-fashioned landline plan from AT&T can cost you $3.50/minute to the UK,
$4.50/minute to Japan, and $5.00/minute to China. Depending on where you lived,
calling someone in the next neighborhood over could be a long distance call, while
calling 50 miles in the other direction would be considered local. Toll-free "800"
long distance numbers were implemented to encourage people to make contact with
businesses without incurring additional charges. Late night TV shows were famous
for using 800 numbers to entice customers into buying Ronco gadgets and term life
insurance policies...
 Here is a great look inside the planning
and operation of the "Minitrack" systems used for
Project Vanguard to track the Sputnik, Echo, Explorer, and other early Earth
artificial satellites during the International Geophysical Year (IGY) activities.
From a 1957 issue of Radio & TV News magazine: "Essentially, the [IBM 704's]
storage function works by means of doughnut-shaped cores, about the size of pinheads,
which are strung on a complex of wires in such a way that several wires pass through
each core. Combinations of electrical impulses on these wires alter the magnetic
states of the cores. A line of cores, some magnetized and some neutral, represents
a number or other collection of symbols in much the same way as a combination of
dots and dashes stands for a word in Morse code. Up to 32,768 of these 'words' can
be stored in the 704's high-speed magnetic core memory. Additional 'words' can be
held..." |
