Today in Science History -
On the May 13, 2005 episode of The Tonight
Show, Jay Leno held a Morse code vs. SMS speed contest between two Ham Radio operators
using Morse code and two Millennials using their smartphones for texting (SMS).
At least one member of the audience thought texting would win. Watch the video to
see if she was right. Mr. Chip Margelli (K7JA) did the sending. He declares, "Let
me assure you that we never saw that message before I flipped the blue card over.
Each message, in rehearsal, was different. The character count was the same as the
one during dress rehearsal, though, to account for the time slot. And they put the
card on the table "upside down" creative to how I flipped it, as you can see on
the video." Mr. Ken Miller (K6CTW) did the receiving...
In 1966, Paul Rockwell wrote a 4-part series
for the ARRL's QST magazine on
for long distance communications (DX) that covered antenna selection and siting
(Part I), economics and construction (Part II), Station Configuration and Receiver
Topics (Part III), and Propagation Quirks and Operating Tips (Part IV). This the
the forth and final installment. One of the handy-dandy items shown is a Geochron
Map-Clock which had a template of the familiar day-night analemma-based curve superimposed
on the projection map of the earth. It was quite a deal in its day, and believe
it or not, the company is still in business offering software-based Map-Clocks and
restoring models all the way back to when they first came out in 1965 (only a year
before it appeared here)...
atomically thin sheets of molybdenum
disulfide both move and block heat. Packing transistors close together raises the
problem of heat frying the devices. Now scientists have developed an artificial
material that is one of the best ever at conducting heat in one direction while
keeping that heat insulated from its surroundings in other directions. The research
might one day help microchips grow more powerful without breaking from overheating.
As electronics continue to miniaturize, greater amounts of heat are getting produced
in a given space, which makes heat control a key challenge in electronic design..."
Do you know what a soroban is? I have to
admit ignorance prior to reading this 1963 "Carl and Jerry" adventure in Popular
Electronics. As with many of these stories, real equipment, people, and companies
were referenced; this time it was the Pastoriza Personal Analog Computer, a modular
electronics system for calculating differential equations. The cost was around $300
(~$2,700 in c2021 money per BLS Inflation Calculator). Analog Devices bought the
company from James Pastoriza in 1969. What does the Pastoriza computer have to do
with the story, you might ask? Nothing, really; it was mentioned in a discussion
Carl and Jerry had when accepting a calculating speed challenge from obnoxious dormitory
mate, Bruce. Jerry would add a series of numbers on his soroban while Bruce would
add them with a pencil and paper. The winner got bragging rights...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Stencils available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Stencils are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
TotalTemp Technologies has more than 40 years
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are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
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how they can help your project.
Science Theme Crossword Puzzle for October 24 has many words and clues related
to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics,
and other technical subjects. The letter "P" figures Prominently in this crossword.
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
Innovative Power Products (IPP) has over
30 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband
couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Please take a couple minutes
to visit their website and see how IPP can help you today.
A year after the two atom bombs were dropped
to end World War II, the newly formed Atomic Energy Commission conducted detailed
detonation tests at the Bikini Atoll, in the South Pacific. Most people more than
40 years old are very familiar with the images of the giant mushroom cloud that
formed over the site. This "Radio in
the Atom Tests" article from the July 1946 issue of Radio−Craft magazine
reports on plans being made to measure and record sound pressure, nuclear radiation,
radio and radar signatures, temperature, light spectrum and intensity, and other
parameters. The information would be used for improved bomb making, nuclear power
generation, medical imaging and treatment, and general research on nuclear fission
and fusion (a fission implosion is to initiate a fusion reaction)...
"Researchers from King Abdullah University
of Science & Technology have proposed a solution to address the widespread public
concern about electromagnetic fields (EMF) exposure from mobile networks. Masters'
student Zhengying Lou, postdoctoral student Ahmed Elzanaty and distinguished professor
Mohamed-Slim Alouini of KAUST proposed that mobile
tethered drones might offer a speedy and environmentally friendly alternative
for receiving terrestrial base stations while alleviating public concerns about
exposure to EMF. Ahmed Elzanaty stated that it is mainly a problem of perception,
but this concern has led to attempts to destroy signaling towers, especially those
associated with the 5G network. He does point out, however, that recent experiments
on animals link some adverse health impacts with long-term exposure to EMF..."
The Civil Aeronautics Administration (CAA),
born in 1940 and now known as the Federal Aviation Administration (FAA, since 1958),
was established originally to regulate the burgeoning commercial airline and cargo
transport air traffic as well as the private aviation activity. According to an
FAA document, on April 3, 1947, CAA controllers began in-service evaluations of
ground approach control (GCA) radar system at Washington National and Chicago
Municipal airports. It was commissioned for official use by the CAA on January 7,
1952, at Washington National Airport. This story from a 1957 edition of Radio &
Television News magazine reports on the system upgrade to long-range radars that
would permit, eventually, continuous coverage across the entire USA...
PCB Directory is the largest directory of
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We have listed the leading printed circuit board manufacturers around the world
and made them searchable by their capabilities - Number of laminates used, Board
thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers,
flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing,
fabrication, assembly, prototype), and more. Fast turn-around on quotations for
PCB fabrication and assembly.
Commercially available radio receivers for
the home had only been around for a couple decades when this advertisement from
Crosley appeared in a 1932 issue of Radio-Craft magazine. I keep looking
in old electronics magazines for an ad featuring my 1941 Crosley model 03CB console
radio, but thus far with no luck. There is a chance, although I have not seen any
direct evidence of it, that the 03CB chassis was sold as a special upgrade to the
less ornate 02CA model. What makes it special is that it was probably one of the
last new radios sold prior to the shift of material usage to military equipment
in World War II...
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
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in the Google search index, RF Cafe returns in favorable positions on many
types of key searches, both for text and images. New content is added on a daily
basis, which keeps the major search engines interested enough to spider it multiple
times each day. Items added on the homepage often can be found in a Google search
within a few hours of being posted. I also re-broadcast homepage items on LinkedIn.
If you need your company news to be seen, RF Cafe is the place to be.
Since 2003, Bittele Electronics has consistently
provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly
services. It specializes in board level turnkey
for design engineers needing low volume or prototype multi-layer printed circuit
boards. Free Passive Components: Bittele
Electronics is taking one further step in its commitment of offering the best service
to clients of its PCB assembly business. Bittele is now offering common passive
components to its clients FREE of Charge.
Dealing with on-site traveling salesmen has
always been a sort of love-hate (or maybe a necessary evil, to put it less extremely)
relationship - for both the salesman and the engineer/technician. Not having been
in the engineering design environment for nearly two decades, I don't know how much
face-to-face contact is made anymore. Up through the early 2000s, I was still occasionally
meeting with components salesmen. In this June 1952 issue of Radio & Television
Mac's Radio Service Shop technodrama, proprietor Mac McGregor takes the occasion
of an afternoon rain torrent to discuss the situation with two of his regular sales
representatives. The open trading of pet peeves and appreciated behavior on both
sides is common sense stuff, but are courtesies often forgotten while in the throes
of the daily work grind. Mac references a book...
"A coalition of 19 smaller U.S. carriers
are calling on the
Federal Communications Commission to move on scheduling a spectrum auction for
licenses in the 2.5 GHz band, saying it’s a critical opportunity for rural and underserved
areas. The service providers, all members of the Competitive Carriers Association
(CCA), sent an October 11 letter (PDF) to Acting Chairwoman Jessica Rosenworel that
urges the regulator to immediately set an auction date for the more than 8,000 mid-band
licenses in its inventory. C Spire, GCI Communications, Union Wireless, Carolina
West, Viaero Wireless, and Nex-Tech Wireless are among some of the signatories..."
Anatech Electronics (AEI) manufactures and
supplies RF and microwave filters for military and commercial communication
systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters,
and RF products. Standard RF filter and cable assembly products are published in
our website database for ease of procurement. Custom RF filters designs are used
when a standard cannot be found, or the requirements dictate a custom approach for
your military and commercial communications needs. Sam Benzacar's monthly newsletters
address contemporary wireless subjects. Please visit Anatech today to see how they
can help your project succeed.
Navy Electricity and Electronics Training
Series (NEETS) Module 4 -
Introduction to Electrical
Conductors, Wiring Techniques, and Schematic Reading. Upon completing this chapter,
you should be able to: 1. Recall the definitions of unit size, mil-foot, square
mil, and circular mil and the mathematical equations and calculations for each.
2. Define specific resistance and recall the three factors used to calculate it
in ohms. 3. Describe the proper use of the American Wire Gauge when making wire
measurements. 4. Recall the factors required in selecting proper size wire. 5. State
the advantages and disadvantages of copper or aluminum as conductors. 6. Define
insulation resistance and dielectric strength including how the dielectric strength
of an insulator is determined. 7. Identify the safety precautions to be taken when
working with insulating materials...
Even though this CW (continuous wave, for
sending Morse code)
transmitter circuit was published in 1955 in Popular Electronics magazine,
it is still legal for today's Amateur radio operator. Portions of the 40-meter and
80-meter bands are still reserved exclusively for CW operation. As of 2021, the
40−meter band (7.025-7.125 MHz) and the 80−meter band (3.525-3.600 MHz)
are both reserved for CW for Hams holding either Novice (no longer issued) or Technician
licenses. Additionally, the 15−meter band (21.025-21.200 MHz) and the 2−meter
band (144.0-144.1 MHz) have CW-only areas. That is different than the frequencies
given in the article, so beware if you are tempted to throw one together for old
time's sake. The value for XTAL will need...