See Page 1 |
2 |
3 |
4 |
5 of the December 2020 homepage
archives.
Monday 21
Right on time for the anniversary of
Pierre and Marie Curie's 1989 discovery of the radioactive element radium is
this article which appeared in a 1944 issue of Radio-Craft magazine. Editor Hugo
Gernsback comments on the recently released (1943) film entitled "Madame Curie*,"
starring Greer Garson as Marie Curie and Walter Pidgeon as Pierre, criticizing it
for not delving more deeply into the technical aspects of radium. Chief among the
objections was the omission of information about how radiation treatment had been
shown to cure some forms of cancer. Indeed, he cited his own experience with a "growth"
on his hand that was successfully treated at a "radium hospital" where the doctor
applied a bulb of radium to the tissue for a mere five minutes. It disappeared in
less than two weeks. Beyond that would be radium's usefulness in generating electricity,
creating wonderful visual effects created by its elemental decay using a spinthariscope...
"From the early days of analog radio receivers
to the
superheterodyne channelized receivers of today, many things have changed. Today,
different technologies are in use and their capabilities have grown immensely. This
article will give you a brief overview of the development of radio receivers. Furthermore,
it will show how channelization has made it possible to use one radio receiver to
listen to many different radio stations simultaneously. In modern telecommunications,
a point-to-point communication medium can be shared among multiple transmitters
in various ways; for example, many different telephone calls can be transferred
simultaneously via the same wire. In this case, each telephone conversation can
be considered as a separate channel on this medium. Another example is traditional
TV or radio stations that are transmitted..."
Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets exceedingly
high standards of quality, performance and excellent value, and are 100% MADE IN
USA. Lotus' RF/microwave products cover frequency band up to 67 GHz. Lotus also
offers an COTS shield enclosures for RF/microwave prototyping and production. All
products are custom designed. We will find a solution and save your time and cost.
Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Since 2008, IEEE's International Symposium
on the Physical and Failure Analysis of Integrated Circuits (IFPA) has on occasion
held an "Art of Failure
Analysis" photo contest. Familiar shapes and patterns occur regularly in nature
at the macro level that can be seen and recognized by almost anyone; e.g., the Nautilus
spiral, the Fibonacci series in plant life, and fractal structures. It takes a high
power optical microscope or even a scanning electron microscope (SEM) to see those
sights in the realm of the very small. Sometimes, though, the images are downright
bazaar and look eerily familiar...
We don't hear much - if any - talk these
days about a certain weapon type being a "peace maker," "game changer," or a "stale
mate proposition." That is because most nations, or for that matter terrorist groups,
have access to some ferocious weapons. The world has operated for a long time on
the Mutually Assured Destruction (MAD) principle, where skirmishes have been fairly
local. Many conspiratorialists as well as arguably rational people believe the real
game at hand is Mutually Assured Financial Destruction (no clever acronym for that
one), where world financial powers cooperatively trade off monetary wins and losses
via what was termed by President Eisenhower the
Military-Industrial Complex. You don't need to be one who wears a tinfoil hat
or keeps your savings buried in a jar in the back yard to suspect at least some
form of malfeasance is going on at the expense of we the little people...
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
Sunday 20
Just in time for Christmas - a
yuletide crossword puzzle for you to work in the last moments of work while
waiting for the boss to give the order to leave early for the lone holiday weekend.
For the sake of avid cruciverbalists amongst us, each week I create a new crossword
puzzle that has a theme related to engineering, mathematics, chemistry, physics,
and other technical words. The clues with asterisks (*) are particular to this December
20th Christmas-themed crossword puzzle. As always, it 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...
Friday 18
Anyone out there old enough to remember when
you were a kid and managed to be able to stay up late enough, maybe on a Saturday
night, to be able to watch the television station sign off the air at night? Here
in the U.S., the custom was to announce the end of the programming day, play the
National Anthem, and then put up the station logo while broadcasting a single tone.
The
tone and test patterns were actually used by TV technicians for calibrating
instruments for use in servicing sets. In 1951 when this TV Station List appeared
in Radio-Electronics magazine, black and white (B&W) was still the
standard, so these images are what you would have seen then. I'm not quite that
old (born in 1958), but I do recognize the stations we could receive at my parent's
home in Mayo, Maryland. Being located between Washington, D.C., and Baltimore, a
pretty good selection of both VHF and UHF...
December 1942 was just a year into America's
"official" involvement in World War II. Already, both wired and wireless communications
had made major advances and were indisputably vital in both the logistical and strategic
aspects of troop movement, supply chains, fighting battles, and evacuation of wounded
personnel. It also played a large part in propaganda campaigns. This was all true
for both Axis and Allied forces.
Ham radio
operators provided a huge boost to the Signal Corps because they came at least
partially trained for the jobs. These dozen and a half photos from the field exhibit
the state of the art at the time. Maybe you'll recognize a father, grandfather,
or uncle in one of them. For that matter, you might even recognize a mother, grandmother,
or aunt...
"Future wireless networks of the 6th generation
(6G) will consist of a multitude of small radio cells that need to be connected
by broadband communication links. In this context, wireless transmission at THz
frequencies represents a particularly attractive and flexible solution. Researchers
at Karlsruhe Institute of Technology (KIT) have now developed a novel concept for
low-cost terahertz
receivers that consist of a single diode in combination with a dedicated signal
processing technique. In a proof-of-concept experiment, the team demonstrated transmission
at a data rate of 115 Gbit/s and a carrier frequency of 0.3 THz over a distance
of 110 meters. The results are reported in Nature Photonics. 5G will be followed
by 6G: The sixth generation of mobile communications promises even higher data rates..."
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
ConductRF, a manufacturer of precision RF
coaxial cable assemblies and connectors, announces the availability of
Phase Stable / Temperature Stable solutions for both commercial and laboratory
precision RF applications. 50 ppm phase accuracy with temperature phase matching
capabilities, low loss and high power options, broad connector choices. Manufacturing
capabilities include solutions built at our ITAR registered facility in Methuen,
Massachusetts, as well as partner facilities in the U.S. and around the world. ConductRF
offers cost effective equivalent and improved RF solutions to all major interconnect
manufacturers, specializing in phase stability over temperature...
Signing up for the U.S. Air Force's delayed
enlistment program in May of 1978 gave me six months to come up to speed on basic
electronics principles. Two years had passed since graduating from high school,
and I had been working as an electrician in the interim. I had done three years
of the electrical vocational program in high school so the fundamentals of electricity
- Ohms law, Kirchhoff's law, AC & DC motors, industrial control circuits, commercial
and residential wiring, etc. - were familiar, but electronics theory - transistors,
tubes, diodes - had not been covered much. Knowing I would be attending many months
of USAF electronics technical school, boning up on the topic seemed prudent. Having
previously built a couple Heathkits, I decided to buy their electronics courses,
along with the
Heathkit ET-3100 Design Experimenter. The model shown in this 1982 Heathkit
catalog...
Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave
connectors, between-series adapters, RF components and filters for wireless
service providers including non-magnetic connectors for quantum computing and MRI
equipments etc. ISOTEC's product line includes low-PIM RF connectors components
such as power dividers and directional couplers. Off-the-shelf and customized products
up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and
20 W test. Quick prototyping, advanced in-house testing and high-performance.
Designs that are cost effective practical and repeatable.
Thursday 17
Imagine if engineers used
physical mock-ups of semiconductor substrates with BB-sized metal balls representing
electrons and holes to design the next whiz-bang transistor. You'd think they were
insane. Seventy-three years ago, before powerful computers and software were available
to simulate the physics, engineers were doing just that sort of thing to figure
out how to design vacuum tubes. This "Monthly Review" feature in the December 1947
issue of Radio Craft magazine has a photo of one of the models. Hills and
valleys in the base represented voltage potentials that influenced the trajectory
of the balls. Pretty clever, really. Also reported was the death of world-famous
physicist and originator of the quantum theory, Mr. Max Planck. He was 89 years
old - not bad for the era...
I when I originally posted NIST Technical
Note 1297, it had the name "Essentials
of Expressing Measurement Uncertainty." Since that time, the NIST website changed
its link to the updated version which now goes by the title of "Guidelines for Evaluating
and Expressing the Uncertainty of NIST Measurement Results." It includes a lot of
new data; in fact, it has been nearly totally re-written. This is a valuable reference
for anyone who needs to understand the proper method for calculating measurement
uncertainties. Preface to the 1994 Edition The previous edition, which was the first,
of this National Institute of Standards and Technology (NIST) Technical Note (TN
1297) was initially published in January 1993...
"University at Buffalo researchers are reporting
a new,
two-dimensional transistor made of graphene and the compound molybdenum disulfide
that could help usher in a new era of computing. As described in a paper accepted
at the 2020 IEEE International Electron Devices Meeting, which is taking place virtually
next week, the transistor requires half the voltage of current semiconductors. It
also has a current density greater than similar transistors under development. This
ability to operate with less voltage and handle more current is key to meet the
demand for new power-hungry nanoelectronic devices, including quantum computers.
'New technologies are needed to extend the performance of electronic systems in
terms of power, speed, and density..."
If you like pictures of très cool-looking
devices involving vacuum-filled (an oxymoron?) glass enclosures, i.e., lamps and
tubes, then you will want to spend a few minutes perusing the personal collection
of Giorgio Basile, of Nivelles, Belgium. Per the homepage of his
Lamps & Tubes website:
"My collection consists of more than 4,000 lamps and vacuum tubes. This is a wide
area! In addition to well known incandescent lamps, radio tubes and cathode ray
tubes, it includes, among others: arc lamps, light sources for the laboratory, transmitting
tubes, camera tubes, flash lamps, microwave tubes, photocells, photomultipliers,
radiation detectors, rectifiers, relays, thyratrons, vacuum gauges, X-ray tubes...
If you had $4,000 to spend on a
desktop computer today, your money would get you a top-end 8-core microprocessor
with at least 32 GBytes of super-fast RAM, a couple TBytes of solid state hard drive
space, and at least a 32" high definition screen monitor. It would be a top-of-the-line
machine any serious gamer would envy. In 1982, the same cash would also get you
a top-of-the-line computer, but it would have a 1-core processor, a whopping 768
KBytes of sub-MHz RAM, a 10 MByte hard disk drive, and a 12" monochrome display.
That describes the IBM PC, Tandy's TRS-80, as well as the Zenith Z-100 PC shown
here from the Heathkit 1982 Christmas catalog. If you were around back then...
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Wednesday 16
This "The National QSO Page" editorial from
the December 1938 issue of Radio News magazine really took me by surprise. Evidently
there was a rift with amateur radio operators over whether Radio News was
attempting to
overthrow the American Radio Relay League's (ARRL) dominance in the Ham realm.
At the time, the ARRL had only been in existence for 24 years. There had been some
previous criticism of the ARRL for not sufficiently (in Radio News' opinion)
defending access to dedicated Ham spectrum and legal transmit power levels, and
also for the ARRL counting among its membership anyone who subscribed to the organization's
QST magazine. The former point is arguable, but the latter seems rather
petty since likely the percentage of subscribers who were not ARRL members, too,
is probably very small. Interestingly, Radio News accused the ARRL of being weak
lobbyists in Washington...
Skyworks is pleased to introduce the
SKYA21043, a highly-integrated, 5 GHz front-end module (FEM) incorporating a
5 GHz single-pole, double-throw (SPDT) transmit/receive (T/R) switch, a 5 GHz high-gain
low-noise amplifier (LNA) with bypass, and a 5 GHz power amplifier (PA) intended
for high-power 802.11p applications and systems. Qualified to AEC-Q104 (Grade 2),
the SKYA21043 meets rugged reliability requirements for automotive applications
including vehicle-to-vehicle (V2V) and vehicle-to-everything (V2X) covering smart
antennas, compensators, and roadside units for automotive infrastructure, backhaul
and cellular...
PCBONLINE supplies complex rigid and flex-rigid
printed circuit boards (PCBs),and
one-stop production with maximum flexibility ranging from prototype sample to mass
production. Rigid-flex, HDI, multilayer, IC-loadboard, LCP 5G optical module, ceramic,
MCPCB. Materials include Rogers, Taconic, Arlon, Isola, Bergquist, Kapton, Panasonic,
and more. After more than 15 years of continuous efforts, PCBONLINE constantly updates
our equipment, improves our technology, and serves you with the highest quality.
Cost and delivery quotations online without the need for multiple phone call and/or
e-mails.
Copper Mountain Technologies (CMT), a leading
developer of innovative RF test and measurement solutions for engineers all over
the world, has produced a video demonstrating how to properly
perform a 2-port calibration on a vector network analyzer (VNA). Virtually interact
with CMT's software to complete a simulated calibration of a 2-port VNA. Note that
the series of dashes and spaces along the video progress bar indicate where the
action stops between steps to allow you time to replicate the action. You will need
to click on the start arrow each time to resume action...
Here are a couple good
Christmas-themed comics from the January 1942 issue of the American Radio Relay
League's (ARRL) monthly magazine, QST. Ironically, the "Old Year" Father Time with
the sickle would not have been able to legally key that transmitter by the time
readers had received this edition, because the U.S. government shut down all amateur
radio transmissions (except a few specially sanctioned civil defense units) immediately
after the Japanese attack on Pearl Harbor on December 7th of the previous year (see
"War Comes"). Although, he would probably have received special dispensation from
the FCC permitting him to send...
Experts and news outlets told Americans
and people of the world not to use hydroxychloroquine (HCQ) as an off-label treatment
for the Wuhan Flu, in spite of its being safely prescribed for decades. We were
told by "experts" that no vaccine could possibly be developed in less than a year.
Now, the American Medical Association (AMA) has changed its mind on HCQ and a vaccine
is being distributed today. Politically motivated fake science has likely caused
suffering and death for an untold number of people. Per
Resolution 509 (p18), November 2020: "RESOLVED, That our American Medical Association
rescind its statement calling for physicians to stop prescribing hydroxychloroquine
and chloroquine until sufficient evidence becomes available to conclusively illustrate
that the harm associated with use outweighs benefit early in the disease course..."
Careful who you listen to - it could kill you.
If you are shopping for a new television
set and are willing to spend $500, you can get a fully assembled and ready to play
Samsung 55" 4K UHD LED Smart TV with Alexa Built-in, or maybe a Vizio 50" 4K UHD
LED Smart TV (UHD = 3,840px x 2,160px = 8,294,400 px^2). The same $500 in 1982
got you a
19" CRT with 525 horizontal scan lines (only 480-490 actually visible), but
theoretically an infinite number of points across each line due to the analog nature
of the signal. Come to think of it, an argument could be made that the old CRT displays
had a higher resolution than the UHD modern digital TV (infinite versus 8.3 million,
respectively). Ditto for the total number of color levels - infinite for analog
versus 16.8 million for digital (8 bits per color = [28]^3). Fully assembled and
ready to play 19" TVs could be bought in 1982 for about the same price, so the motivation
for going to the trouble of building your own set was mostly pride and personal
satisfaction...
MPDevice (MPD) has become a trustworthy
and reliable company in the global RF market as a manufacturer of
passive RF devices. Included
are attenuators and terminations, coaxial connectors, adapters, and cable assemblies,
DC blocks, surge arrestors, power combiner / dividers, and directional couplers.
The Korean Telecommunication market is now entering into the era of hyperconnected
society. With continuous enhancement in R&D capabilities and quality control,
MPD will continue in an effort to become the No. 1 technologically innovative
company with a focus on the emerging 5G marketplace.
Tuesday 15
The old adage about pioneers taking the
arrows is true in many realms - not just the exploration and settling of the wild
west. This story entitled "Sparks
on Ice" recounting the trials and tribulations of the troops who installed and
debugged the first arctic directional beacons appeared in a 1945 issue of Flying
Age magazine. "Sparks" (or "Sparky") was an endearing nickname given to early radio
operators who used spark gap transmitters to send out their Morse code messages.
It stuck around for many years after better transmitter systems were developed -
although it is not very often heard today. The most interesting part of Mark Weaver's
article is a discussion of the many atmospheric phenomena that affect radio waves
of various wavelengths. A lot of smart people - enlisted, commissioned, and civilian
- sacrificed mightily...
Remember the era when those big parabolic
satellite television antennas (TVRO - television receive-only) began appearing
on lawns all over the place? Some people painted them with camouflage to help disappear
them from view, while others painted them to match the themes of their houses. Some
got really obnoxious and painted targets or, even worse, big ugly eyeballs on the
antennas. Most systems at the time operated on C-band, which explains, along with
lower sensitivity receivers, the large size. The earliest antennas and receivers
which came to market in the late 1970s coincident with the first TV broadcast satellites
cost more than $10,000. By 1982 when this Heathkit Christmas catalog was printed,
prices were down to just a few thousand dollars. Nowadays, a much smaller antenna
operating at Ku-band is provided at no cost...
"A hacker can reproduce a circuit on a chip
by discovering what key transistors are doing in a circuit - but not if the transistor
'type' is undetectable. Purdue University engineers have demonstrated a way to disguise
which transistor is which by building them out of a sheet-like material called black
phosphorus. This built-in security measure would prevent hackers from getting enough
information about the circuit to reverse engineer it. The findings appear in a paper
published Monday (Dec. 7) in Nature Electronics. Reverse engineering chips
is a common practice - both for hackers and companies investigating intellectual
property infringement. Researchers also are developing X-ray imaging techniques
that wouldn't require actually touching a chip..."
Although the original purpose of this note
was just to announce a couple post-WWI era
U.S.
Air Force recruitment posters I found in The Saturday Evening Post magazines
back in the late 1940s, some info I found regarding the newest USAF logo might also
interest you. There is a plethora of old Air Force posters available for viewing
on the Internet, but I haven't seen these two, which are particularly directed toward
flight officers and the newfangled jet aircraft of the future. Operational jet-powered
fighter craft did not appear until the final year of World War II, although
Germany did have their Messerschmitt Me 262. Except maybe for the C-130, you probably
won't see any propeller-driven aircraft in today's USAF promotional material. If
you have any cause to display the USAF's new (relatively) wings symbol, be sure
to consult this entire section of regulations governing the proper...
COMSOL's Jiyoun Munn has an article posted
on the Interference Technology website entitled, "The
Vital Role of Simulation for Virtual EMI and EMC Test Environments." I first
saw it reproduced in NASA's Tech Briefs. He begins: "Before deploying microwave
and millimeter-wave devices and systems within 5G, the Internet of Things (IoT),
and high-speed wireless communication, it is essential to predict their performance.
This need has increased the demand for virtual test platforms through simulation
software. High carrier and system bus frequencies are necessary for high-data-rate
communication between multiple devices present in such systems. However, increased
operational frequencies may induce undesirable and troublesome electromagnetic compatibility
(EMC) and electromagnetic interference (EMI) issues, especially when communication
is congested. Moreover, the impact from other physics is no longer negligible..."
Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
Homepage Archive Pages
2024:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2023:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2022:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2021:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2020:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2019:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2018:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2017:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2016:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2015:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2014:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2013:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2012:
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 (no archives before 2012)
|