Today in Science History -
 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 for 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
the
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
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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
website visits each weekday.
RF Cafe is a favorite of engineers,
technicians, hobbyists, and students all over the world. With more than 16,000 pages
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
PCB assembly
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
News magazine's
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...
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio
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...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
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project.
 In this 1946 issue of Radio-Craft
magazine, editor and über electronics guru Hugo Gernsback reviews "Secret
Communications" methods used throughout history, including Alexander Graham
Bell's "Photophone" that used a modulated light beam for transmission. With World
War II having recently ended and devices such as the "Enigma Machine" developed
by the Germans for secure encryption of messages, secure communications was high
on the priority list of government and military strategists. Gernsback also suggests
ultrasonic systems for wireless communications, and a multiple channel scheme suggestive
of the m−ary method widely used today...
 "Can a small wireless power startup really
use its 'RF
Holography' technology to charge personal electronics from several meters away,
without irradiating their users? Join ED's Lee Goldberg as he takes a deep dive
into the theory behind the system. Our recent story 'Wireless Power System Approved
by EU and UK Claims to Charge Mobile Devices Without Frying Users' caused quite
a stir amongst our loyal reader community. In fact, more of our sharp-eyed readers
took the time to weigh in on the technology's relative merits than any other story
I've written in the last decade (or two). Nearly all of their responses were even
more skeptical than I was of Ossia's claims to be able to deliver meaningful amounts
of power to devices multiple meters away via either 2.4- or 5.8-GHz RF beams..."
 This was a multi-part series published by
Radio & Television News magazine in the days when
color TV was the domain of the more well-to-do folks on the block. Needless
to say (but I'll say it anyway), nobody I knew had color TV before around 1968.
One of my friend's father owned a fairly profitable gas station and service garage,
so they were the first to have one. For some inexplicable reason (I jest), his mother
never allowed more than one or two of us into the house at a time, so we drew straws
to see who got to witness that fabled miracle of technology. I was about third in
line. Insomuch as the 1960s were a much more polite and private time than the present,
peeking through a living room window for a preview was expressly verboten. In fact,
going into a friend's house for any reason was rare. The privileged appointments
were strictly adhered...
 ConductRF FPA Cable Assemblies use a unique,
Low Loss, high performance
Semi-"FlexiForm" Cable that is formable, but flexible, providing system designers
with a versatile solution for High Frequency applications. The product also allows
for very tight phase matching to ±0.2º. Available in three common cable diameters,
with the benefits of higher operating frequencies, shielding effectiveness and stability
performance over traditional standard Hand Formable cables, these solutions enhance
any application requiring higher performance. ConductRF's FPA Cable Assemblies are
manufactured using the latest induction soldering techniques to best ensure the
highest quality and performance...
 Thanks to a tip by RF Cafe visitor and contributor
Bob Davis for letting me know about a very capable point-to-point
RF system planner called Radio Mobile (URL updated since original expired),
by Canadian Ham radio operator Roger Coudé (VE2DBE). There is another similar freeware
program available called AlphiMax, but it requires that you upload your system data
to a remote server - a potential confidentiality conflict. Radio Mobile uses GPS-based
terrain information obtained from the U.S. Department of Commerce NTIA/ITS Institute
for Telecommunication Sciences Irregular Terrain Model (ITM) database...
 RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite of engineers,
technicians, hobbyists, and students all over the world. With more than 16,000 pages
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.
 Have you noticed how
heavily burdened utility poles (formerly referred to as electric poles or telephone
poles) are these days? Many of the decades−old creosoted wooden poles originally
were designed to carry a single set of high voltage distribution lines (13.8 kV)
and a multiconductor telephone cable containing twisted pairs. Look around now and
you will see at least twice that number of cables, and often three times as many
due to multiple coaxial and fiber optic cables and needing to route extra AC power
circuits (of larger gauge to handle higher current) in increasingly crowded areas.
Notice how many are leaning over (particularly at corners) and/or are being supported
with additional guy cables and/or splints. Half a century ago when music, talk,
and television was broadcast over the air, the need to string wire all over the
landscape was not necessary. Some people complained about "ugly" TV and radio station
broadcast antennas...
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