When I first read the title for this article,
Look at the PC Market," I was thinking personal computers, not printed circuits.
It being from a 1972 issue of Popular Electronics, my assumption was that the photos
of circuit boards were from early kit format computers, but then it finally dawned on
me that there were no personal computers in 1972 - not even in kit form. Actually, that
is not entirely true since there were advertisements for hokey contraptions called "computers"
that combined some switches, logic gates, and LEDs for implementing simple multiple choice
true/false testing boxes or rudimentary (with emphasis on "rud[e]") calculators. Getting
to the real story, though, the 1970s was the decade where printed circuit boards (PCBs)
were replacing point-to-point wiring wherever possible. If you opened a radio or television ...
Chapter 12 of the U.S. Navy's basic electronics
training course discusses
electromagnetism. It follows on the heels of the sections introducing magnetism and
electrical currents. The Navy (and the Air Force, I must add) is renowned for its high
quality training and for turning out graduates that perform highly in both their service
duties and in private industry after separation. It describes the electromagnet as being
like a natural or artificial magnet in its attractive force, is tremendous and can hold
tons of iron. Because this magnet is powered by an electric current, the magnetism can
be turned on and off with the flick of a switch. Electrically-powered magnets are called
electromagnets. Electromagnets come in all sizes and shapes ...
Infinite Electronics, a global supplier of RF and
Microwave components and assemblies, is looking for a
Technical Support Representative. We have an exciting opportunity for a technically
savvy individual with proven customer facing and team skills to round out our Sales and
Tech Support team. Job Summary: The Technical Support Representative's duties and responsibilities
include, but are not limited to: (80%) Resolving customer technical questions directly
through telephone, email, chat or other methods of communication, or via the Sales and
Service Representative. The TSR will identify customer needs and resolve routine customer
technical questions by identifying the appropriate RF/Microwave part, recommending additional
or alternative ...
"A new electronic
skin with magnet-sensitive capabilities developed by researchers
in Germany can turn someone into a human compass, providing opportunities for navigation
as well as virtual-reality and other applications. Researchers at Helmholtz-Zentrum Dresden-Rossendorf
(HZDR) developed the e-skin, which can detect and digitize body motion as it corresponds
to the Earth's magnetic field, they said in an HZDR news release. An ultra-thin golden
foil on the middle finger is all that's needed to control a virtual panda with the help
of the Earth's magnetic field, thanks to new research to develop an electronic skin by
researchers in Germany. The e-skin is extremely thin and malleable, which means ..."
KR Electronics designs and manufactures high quality
filters for both the commercial and military markets. KR Electronics' line of
filters includes lowpass, highpass,
bandpass, bandstop and individually synthesized filters for special applications - both
commercial and military. State of the art computer synthesis, analysis and test methods
are used to meet the most challenging specifications. All common connector types and
package form factors are available. Please visit their website today to see how they
might be of assistance ...
Have you ever used any of these
voltage-variable capacitor (VVC) types: varicaps, epicaps, minicaps, voltacaps, capistors
and varactrons? If you answered "no, but I have used varactor diodes," then the more
correct answer would have "yes, I have, but by a different name." Construction was similar
for all variations. This article from a 1969 issue of Radio-Electronics magazine
reports on some of the earliest forms of diodes specifically designed to use a reverse
bias on the PN junction to control the effective capacitance of the device for use in
frequency tuning circuits. The first uses were for electronically tuning local oscillators
in mixing stages, and then for making tunable filters. Capacitance ratios greater than
10:1 with some VVCs allowed tuning over a very wide range. At the time the article was
written, there was not universally agreed upon schematic symbol for the VVC, as illustrated
in Figure 2. Varactor-tuned television channel selectors ...
Do a WWW search for
and you will find thousands of pages, including a few here on RF Cafe. However, if you
want an example of how to implement the transfer functions in a spreadsheet or software,
examples of actual code are elusive (other than maybe a Matlab or MathCAD worksheet).
As one who has incorporated equations for Butterworth, Chebyshev Type 1, Chebyshev
Type 2, and other filter functions in many spreadsheets and software over the past
few decades, I figured it might be useful to post snippets of my code so that someone
else can copy and paste it directly into other work. BTW, I do not consider myself to
be a filter expert by any means and there is no ground-breaking knowledge here; it's
just hopefully easier to find. Writing a macro to use in a spreadsheet is the preferred ...
Elite Electronic Engineering, of Downers Grove,
Illinois, if offering as a free download this whitepaper titled, "Guide to FCC Certification for Part 15C Wireless Transmitters." Elite
is a recognized Telecommunication Certification Body (TCB) for the FCC, Foreign Certification
Body (FCB) for Canada, and Notified Body (NB) for the European Union under the Radio
Equipment Directive. These credentials assure the speedy and convenient processing of
your approval. FCC Certification Elite is designated by the United States government
as an accredited Telecommunication Certification Body (TCB). We provide FCC compliance
testing services to manufacturers of radio-frequency transmitting devices ...
Triad RF Systems, a top-tier designer and manufacturer
of RF and microwave amplifiers, announces the introduction of their
TTRM1210 bi-directional amplifier, a wideband GaN Bi-Directional
Amplifier (BDA) that operates from 30 MHz to 2700 MHz and produces over 8 W
of transmit power. The receive side has over 20 dB of gain to overcome losses between
the antenna and the radio. The noise figure is 2 dB which makes the BDA practically
invisible to the system. Switching between transmit and receive can be done either automatically
when RF is sensed at the radio port, or manually switched by the radio or user. One of
the smallest BDAs in the industry measuring only 3.25 x 2.12 x 0.53 inches, this feature
rich BDA is also one of the most efficient. While producing 8 W of RF power ...
"The Physics World 2018 Breakthrough of the Year
goes to Pablo Jarillo-Herrero of the Massachusetts Institute of Technology (MIT) in the
US and colleagues for making the discovery that led to the development of 'twistronics,'
which is a new and very promising technique for adjusting the electronic properties of
graphene by rotating adjacent layers of the material. The technique was first used by
the team to create 'magic-angle graphene,' which behaves like a high-temperature superconductor.
Nine other achievements are highly commended in the Top Ten Breakthroughs of 2018 and
cover topics ranging from the first full body PET/CT scan to a zero-carbon aeroplane
propelled by a jet of ions. Graphene is a layer of carbon just one atom thick that has
a honeycomb lattice. Bilayer graphene ..."
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. Take a couple minutes
to visit their website and see how IPP can help you today ...
Copper Mountain Technologies develops
innovative and robust RF test and measurement solutions for engineers all over the world.
Copper Mountain's extensive line of unique form factor
Vector Network Analyzers
include an RF measurement module and a software application which runs on any Windows
PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result
is a lower cost, faster, more effective test process that fits into the modern workspace
in lab, production, field and secure testing environments ...
Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. 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 2018 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. An intro video takes
you through the main features ...
An ancient legend tells us that nearly 5,000 years
ago an Emperor of China had a small statue of a man mounted on his chariot. This statue
was pivoted at the base and one outstretched arm always pointed to the south. In those
ancient times, this action must have seemed truly miraculous - probably the Emperor used
his statue more to impress his subjects than he did to find his way. This legend is the
first report of man's use of a black or lead-colored stone called
magnetite. About the time of Christ, magnetite was rediscovered by a Grecian shepherd.
He noticed that the iron of his staff was attracted to certain stones. But for nearly
another 1,000 years, no particular use was made of this discovery ...
A while back I mentioned that Mr. Glen Robb, owner
Antenna Test Lab, had an article in the October 2018 issue of
Microwaves & RF magazine titled, "Assemble
Antennas with 3D Printing." He told me a future issue of the ARRL's QST
magazine would also be running an article on his 3D antenna printing project. It just
showed up in the January 2019 edition. Unfortunately, QST does not have a publically
accessible version of the magazine, but for ARRL members you can find the article under
the title of , "3D-Printed Antennas," on page 67. It is featured in Paul Wade's monthly
"Microwavelengths" column. "3D printers have become quite inexpensive, and many hams
have acquired one. Printing hard-to-machine horn and antenna feeds is a natural task
for 3d printers ..."
The first RF Cafe Poll for the new year asks, "Do you Plan to Change Jobs
in 2019?" Voting is totally anonymous and does not require registration. I also will
not hit you with a full-page advertisement, require you to submit an e-mail to view the
poll results, or set a cookie with the poll code. My cardinal rule on RF Cafe is to never
subject visitors to any form of treatment I despise when going to a website. Thanks for
your participation ...
"Engineers have succeeded in fabricating
topological LC circuits arranged in a honeycomb pattern where electromagnetic
(EM) waves can propagate without backscattering even when pathways turn sharply. These
circuits may be suitable for use as high-frequency electromagnetic waveguides, which
would allow miniaturization and high integration in various electronics devices, such
as mobile phones. NIMS succeeded in fabricating topological LC circuits arranged in a
honeycomb pattern where electromagnetic (EM) waves can propagate without backscattering
even when pathways turn sharply. These circuits may be suitable for use as high-frequency
EM waveguides, which would allow miniaturization and high integration in various electronics
devices, such as mobile phones ..."
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 ...
Band" (CB) is the common reference to these unlicensed two-way radio service transceivers,
the official name for the spectrum allocated by the FCC to their operation is "Citizens
Band Radio Service" (CBRS). It was originally called just "Citizens Radio Service," but
the popular use of "Band" caused the FCC to incorporate the additional term later on.
Early Part 95 Class D citizens band radios offered up to 23 channels in the 11-meter
band from 26.965 MHz through 27.255 MHz. CB radio channels increased to 40
in 1977 due to the immense popularity at the time (long before cellphones) - recall the
"Convoy" song. The 11−meter band was re−allocated from the amateur radio spectrum
in 1958 (to the great dismay of Hams). CB radios are still used heavily by truckers who
don't like the idea of "Big Brother" listening to and recording conversations ...
Not everyone is an ardent observer of astronomical
events, but most people are still as awestruck as were primitive peoples when a lunar
eclipse or solar eclipse occurs, or when a massive meteor shower happens. Centuries ago
most of those phenomena were not predicted because the mathematics and mechanics of gravity
were not known. The kings' best astronomers and astrologers leveraged ignorance to influence
ruling policy similar to how politicians and activists do today. The folks at the Telescopic
Watch website created this infographic titled "Must-See
Stargazing Events for 2019" which highlights the 10 most significant astronomical
events of the new year. First up is a total lunar eclipse on January 21st ...
"The inconvenient truth of future
5G networks is that their increased high-speed bandwidth, and the
use of the millimeter wave spectrum (the radio spectrum above 30 GHz) to achieve it,
comes at a price: Those radio signals barely propagate around the corners of buildings.
To overcome this issue, the strategy has been a combination of small cells with massive
multiple-input multiple-output (MIMO) antennas to increase coverage. Small cell deployment
will be so extensive that the Small Cell Forum predicts 5G small cell will overtake 4G
small cells by 2024. The total installed base of 5G or multimode small cells will reach
13.1 million by 2025, constituting more than one-third of the total small cells ..."
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 / downconverters. Since the
conception of WFT, we have introduced products that have been purchased by a wide range
of customers, from hobbyists to education facilities to government agencies. Worldwide
customers include Europe, Australia, and Asia. Please contact Windfreak today to learn
how they might help you with your current project