Today in Science History -
"Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his April 2021 newsletter that features
his short op−ed entitled "A
Wall of Interference!" The allusion is to the "wall" of antennas that typically
comprises cell tower installations. Each antenna represents a source of potential
signal interference for collocated antennas' receivers whose connected front end
low noise amplifiers must successfully reject out-of-band signals and/or the inbound
spurious mixer products generated by out-of-band signals. Sam also presents some
relevant industry news items as well..."
Electronic mail did not start out as we know
it today, whereby anyone with access to an Internet-connected device can compose
and send a typed message to a similarly equipped receiver. The first electronic
mail message was sent (and received) on November 1, 1960, between post offices in
Washington, D.C., and Chicago, Illinois. This article from Popular Electronics
magazine takes you on a step-by-step tour of how the
Speed Mail system worked, including its dedicated shortwave radio links between
participating cities. Great care was taken in an attempt to assure message confidentiality
by having the letter opened and scanned automatically inside a sealed machine on
the transmit end and then printed and placed in a sealed envelope on the receive
end. Knowing what we know now about government snooping...
Res-Net Microwave has a complete line of
precision RF & microwave components including attenuators, terminations,
resistors, and diode detectors for commercial, military, and space applications.
Products range from the small flange type to large 2,000 watt connectorized power
attenuators and/or terminations at frequencies up to 26.5 GHz. In-house photo
etch and laser trim capability. The company is a leader in development and production
of the films required for these type of RF/microwave components. Please check out
Res-Net Microwave's website to see how they can help with your current project.
After having read many articles about Dr. Lee
de Forest, it seems the poor guy was besieged his entire life by envious and/or
belligerent electronic communications compatriots who sought to defame him and/or
deny him of monetary rewards. This January 1947 issue of Radio-Craft magazine
includes a dozen or so pieces written by friends and colleagues who recognized the
momentous struggles and achievements of Dr. de Forest. Such burdens of
fame are borne by many - if not all - persons of similar celebrity. Dogged persistence
is the order of the day for experimenters and breakers-through of assumedly impenetrable
walls. Guys like de Forest lived by the old adage recommending that "if at
first you don't succeed, try, try again." You'll be amazed at how de Forest whipped
- almost literally - that thing which was preventing his
wireless telephone from working. BTW, as I've pointed out before, you will find
the good doctor's last name written as "de Forest, DeForest, and De Forest."
As evidenced by his signature...
Modelithics is pleased to announce the release
version 21.4.5 of the Modelithics Qorvo GaN Library for use with Keysight Technologies'
Advanced Design System and Cadence AWR Design Environment. Version 21.4.5 of the
Modelithics Qorvo Gallium Nitride (GaN) Library includes a total of 82 models containing
59 packaged power models, 17 GaN die power transistor products and 6 small-signal
models. This release offers a non-linear model for the Qorvo QPD1028L, a 750W (P3dB)
discrete GaN on SiC HEMT using Qorvo's QGaN50HV process. This device comes in an
NI-780 package (eared). The Angelov-based large-signal model includes an advanced
model feature for enabling intrinsic I-V sensing and is valid for Class AB operations...
At first I thought this was a news item about
Maxwell Smart's archenemy. "A complex network of randomly interconnected logic gates
creates conditions that could thwart hackers. Not all
chaos is bad. In the case of programmable chips, chaos can be harnessed to create
a unique digital identifier. Think of it as a fingerprint—only, instead of distinctive
loops and whorls on human skin, this is about the unique physical variations present
in silicon chips. These minute differences, often at an atomic level, vary from
chip to chip, even if they are manufactured together. The physical variations can
be amplified using a technology called physically unclonable functions (PUFs) to
create a signature that is unique to a specific chip..."
Here is a little electronics hobbyist humor
in the form a comic series titled "Hobnobbing with Harbaugh," compliments of
Popular Electronics magazine. Dave Harbaugh drew many comics for technical
magazines. For the non-Ham, QSL is the Q-code for "'I confirm that I received your
transmission." You don't need to be an amateur radio operator to appreciate these
comic strips, though. Note that with it being 1963, the husband and wife are shown
sleeping in separate beds - just like in the TV shows of the era like The Dick Van
Dyke Show and I Love Lucy. BTW, the kid in the crib is spelling out -..(d) .-(a)
-..(d) -..(d) -.--(y).
ConductRF is continually innovating and
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amplitude and phased matched VNA applications as well as standard & precision
RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the
iBwave component library. They also provide custom coax solutions for applications
where some standard just won't do. A partnership with Newark assures fast, reliable
access. Please visit ConductRF today to see how they can help your project!
As of the year 2020 there was an estimated
7.8 billion people in the world. Most of them, thanks to the technology invented
and provided by capitalist societies, have some form of Internet access. A large
fraction of them have paid nothing for it (while hating those who provided it) -
I'm just sayin'. Out of those 7.8B people, surely a handful have already or will
in the future search the World Wide Web (WWW) in pursuit of information on vintage
test equipment, either as fodder for some publication, for reference in obtaining
particular models or for service data. In the interest of those folks, I go to the
trouble of scanning and posting content like this test equipment advertisement by
Superior Instruments (aka SICO)...
Copper Mountain Technologies will be presenting
a webinar entitled "Introduction
to Antenna Aperture," hosted by none other than Robert Zavrel (W7SX), author
of "Antenna Physics: An Introduction." It begins at 2:00 pm EST on Tuesday,
April 27th. Robert is an accomplished RF Engineering Executive with 30 years of
applicable experience and a verifiable consistent record delivering technical innovation,
streamlined operations, increased productivity, and exceptional leadership and mentoring.
The concept of antenna aperture is perhaps the most important antenna specification
that is largely ignored by amateur texts. Many commonly published equations for
radio engineers and amateurs alike rely upon antenna equations that employ aperture
but never explain the fundamentals, they simply give the equations and leave it
at that. The purpose of this brief overview is to explain the concept and relate
it to why we should care. Virtually all advanced texts on antenna theory explain
aperture in detail since their goal is to provide deep understanding of the subject
This is an attempt to provide an empirical fundamental understanding...
Amateur radio operators, as with hobbyist
participants in many other realms, historically have contributed significantly to
the efforts of their professional counterparts. I have written of it often. This
particular instance is where signal measurements in the Ham bands during a
total eclipse of the sun (August 31, 1932 in this case) were used to assist
scientists debating the merits of rival theories relating to origin of ionization
in the Kennelly-Heaviside Layers of the E and F regions, both of which were proposed
in 1902 (yes, the Heaviside of step function fame). Long distance (DX) communications
are dependent upon such ionization to reflect radio signals that would otherwise
pass through the atmosphere and into space. The test at hand would settle the argument
since the one should fail if ionization was unaffected during totality.
Nokomis, a high technology research and development
company, is seeking a
PCB Layout Designer
to design complex, multilayer PCBs with high density BGAs using Mentor PADS. This
position will be responsible for completing a variety of tasks in a cost-effective
and time-efficient manner. The ideal candidate will have experience in the layout
of a mixture of different types of technology boards, thru hole, SMT, and mixed
with possibly blind and buried vias. The boards will have a wide range from very
simple one-layer, single sided placement, to multi-layer double sided placement.
Technology ranges from analog to high-speed digital layouts. This is a contract
Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
It takes a while - and money - to accumulate
issues of the vintage electronics magazines for posting articles here on RF Cafe.
Often I can find groups for sale that comprise a full calendar year, but often they
are groups of random months and years. That makes getting a complete series of articles
like this one on "How
an Electronic Brain Works" difficult. A lot of times installments appear every
other month, so when a series has more than ten articles, it can run well over a
year. For instance Part I of "How an Electronic Brain Works" appeared in the
September 1950 issue of Radio-Electronics. The final chapter, Part XIII,
appeared in October 1951. Throughout the series, authors Edmund C. Berkeley and
Robert A. Jensen describe the workings of "Simon," their compact electronic computer
- some even call it the first "desktop computer." Here is an article (with photos)
about "Simon" in the November 1950 Scientific American magazine...
ConductRF offers RF Engineers a large selection
Hi Flex cable for vector network analyzers (VNAs). We have standards
for applications at 18-40 GHz, 50 GHz & 70 GHz. Our torque resistant
connector heads and phase stable constructions ensure great performance for many
tests to come. Other key features include: 2.92 mm, 2.4 mm & 1.85 mm
connector options, low VSWR & insertion loss, low phase change with flexing,
options available swept right angle connectors. ConductRF VNA series provides customers
with reliable ruggedized solutions for Lab and Production Vector Network Analyzer
testing. With options for 18 GHz, 26.5 GHz, 40 GHz, 50 GHz, &
70 GHz, these cables offer cost leading alternatives to original OEM VNA cable
"Researchers at the National Institute of
Standards and Technology (NIST) and collaborators have demonstrated an
atom-based sensor that can determine the direction of an incoming radio signal,
another key part for a potential atomic communications system that could be smaller
and work better in noisy environments than conventional technology. NIST researchers
previously demonstrated that the same atom-based sensors can receive commonly used
communications signals. The capability to measure a signal's angle of arrival helps
ensure the accuracy of radar and wireless communications, which need to sort out
real messages and images from random or deliberate interference..."
As with so many things we take for granted
today, the U.S. Army Signal Corps' nationwide announcement on January 25th, 1946,
that the first
(EME, aka moonbounce) contact had been made by radar was a big deal. Hams make EMEs
on a regular basis, although it still is not a simple accomplishment and takes some
special equipment. The term "selsyn" used in the article is a portmanteau of "self-synchronous,"
and refers to a device for precisely positioning something like an antenna. Magazine
editor Hugo Gernsback included some kudos from contemporary notables like Audion
inventor Lee DeForest and Radio Corporation of America (RCA) president David Sarnoff
for having predicted the method and results in a 1927 article entitled "Can We Radio
the Planets? See "Moon-Radio Predicted in 1927" at the bottom of the page.
Pasternak has an interesting article on
the Microwave Product Digest website entitled, "CubeSats:
An Emerging Market for the Microwave Industry." In framing the story with the
history of satellite communications, the author hearkens back to 1945 when Arthur
C. Clarke ("2001: Space Odyssey") described in Wireless World magazine
a way that communications could be achieved via Earth-orbiting "Extra-Terrestrial
Relays." Pasternak begins, "Spacecraft in low, mid, and high orbits provide
a diverse array of services from TV and radio broadcast to terrestrial and maritime
communications, remote sensing, and navigation and timing. Not surprisingly, the
satellite industry has been a steady consumer of RF and microwave components for
more than five decades, and the pace is likely to increase. The driver of this good
fortune is the 'smallsat' that makes it possible for even companies and governments
without enormous financial resources to create space-based services..."
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...
Until the last couple decades, people of
the world recognized and called out evil by name when it reared its ugly head. Except
for subversive imbedded agents, media outlets - radio, television, print, speeches,
etc. - openly and vigorously condemned and attacked the enemy of its country's traditional
way of life. The theme ran deep and wide in news reports and in magazine features.
This advertisement for Air Adventures magazine which appeared in early 1940s
Radio News magazine is an example. In the place of politically correct
speech that doesn't dare to offend an entity which openly and maniacally seeks to
kill you we had the vast majority of media promoting nationalism and patriotism
in order to defeat the enemy. As with just about everything, eBay is a good source
of these vintage Air Adventures magazines. This particular publication only
ran for three editions. However, there were plenty of other titles that featured
stories of heroic adventures against the Nazi scum ;-) Flying Aces magazine...