Listen to the
RF Cafe Podcast. At the time this Mac's Service Shop episode appeared in
a 1957 issue of Radio & TV News magazine, electronics technicians were
beginning to see a lot of
transistorized radios, televisions, record players, and tape recorders showing
up in place of the very familiar vacuum tube models. It was a whole new ballgame.
To complicate matters, biasing, interstage coupling, and tuning circuits were in
many ways different requiring re-learning what a "typical" circuit looked like,
and the introduction of printed circuit boards in place of point-to-point wiring
made changing components more difficult. Delaminating metal traces was easy to do
on early PCBs when using the big, high thermal inertia soldering irons required
for larger and more heat-tolerant components. Author John T. Frye used these
Mac's Service Shop stories...
2.4 mm to 3.5 mm Adapter Series are designed based on precision microwave
interconnection technologies. These adapters are manufactured to precise microwave
specifications and constructed with either male or female gender sides. The precision
microwave connector interfaces ensure an excellent microwave performance up to 34 GHz.
Impedance: 50 Ω, VSWR: 1.25:1 (max) to 34 GHz, Body: Stainless
steel (passivated), Center Contact: Gold-plated brass...
"In recent years, engineers worldwide have
been trying to create electronic components that are increasingly flexible and versatile,
as this could enable the fabrication of more sophisticated devices and robotic systems,
electronic skins (e-skins) or wearable sensors. The overall objective of this
particular area of research is to develop flexible electronics that can be manufactured
and implemented on a large scale, but that also exhibit a high device density and
excellent performance. A class of materials with particular promise for developing
flexible electronic parts are two-dimensional (2-D) semiconductors, such as molybdenum
disulfide (MoS2). While this material has many advantageous mechanical, optical
and electronic properties, it has so far proved challenging to build large-scale,
flexible integrated circuits with a high device..."
Most people have heard of the incredibly
Norden bombsight (see video of the Norden bombsight) that was credited for revolutionizing
accuracy of heavy bombers like B-17s, B-24s, and B-29s. It was an electromechanical
device that took bombardier inputs of altitude, airspeed, heading, and wind speed
and direction, then calculated the impact point of the bomb. An accuracy of 75 feet
was claimed under ideal conditions - provided by a mechanical computing device.
By 1956 when this article was published (eleven years after WWII and three years
after Korea), the Norden had been replaced by radar-integrated bombing systems.
Additionally, ground-based radar measurement systems were in use to train aircrews
without the need to drop physical bombs. Instead, virtual bombs were launched and
computers in a Radar Bomb Scoring (RBS) unit...
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. Products are designed and manufactured in the
EMA Structural Forensic Engineers wrote requesting
addition to the Expert
Witness, Tech Services,
and Forensic Engineering
pages on RF Cafe, which I was glad to do*. EMA assists architects, the legal profession,
and the insurance community in the investigation and redesign of structures. We
solve design issues of already designed buildings and performing damage assessment.
Damage assessment of roofs, hail damage inspections, forensic building damage inspections,
forensic engineering, flood damage assessments, and hurricane damage assessment.
*I also cleaned up a lot of expired company links - they
need some forensic services now.
SF Circuits' specialty is in the complex,
advanced technology of PCB
fabrication and assembly, producing high quality multi-layered PCBs from elaborate
layouts. With them, you receive unparalleled technical expertise at competitive
prices as well as the most progressive solutions available. Their customers request
PCB production that is outside the capabilities of normal circuit board providers.
Please take a moment to visit San Francisco Circuits today. "Printed Circuit Fabrication &
Assembly with No Limit on Technology or Quantity."
It has been three or four decades since I
have seen anything about a
Lecher Line, the last time in memory being in a college lab. It might have been
a physics lab, but most probably an EE lab. We used one to measure wavelengths of
signals from an RF generator. The apparatus looked sort of like the one in the Wikipedia
link, only just a little more modern (but not much more, being typical school equipment).
This new patents report from a 1947 issue of Radio-Craft magazine has a
waveguide version of a Lecher Line that supposedly was able to do more precise measurements
of very short wavelengths by providing for detecting the internal wave over multiple
wavelengths instead of just a single half wavelength. It was developed at Bell Telephone
Linx Technologies, a Merlin, OR, based developer
and manufacturer of antennas, is pleased to introduce the latest additions to the
FPC Series of flexible embedded antennas. The FPC Series antennas excel in a
wide range of applications, including 5G cellular, WiFi 6/6E, low-power wide-area
networking (LPWA), and ISM. In this latest release, Linx is adding two 5G antennas,
a WiFi antenna supporting the new 6 GHz band, a 433 MHz LPWA offering,
and an ISM antenna supporting both 868 MHz and 915 MHz. The FPC Series
provides ground plane independent dipole embedded antenna solutions comparable in
performance to external antennas. The flexibility and adhesive backing make the
FPC Series easy to mount in unique and custom enclosures...
Even in this time of readily available computers
(including your smartphone) and printers, having a set of
rubber stamps for common electronics symbols would be pretty handy; there are
some Neanderthals among us who still use pencil and paper on occasion. Simpler symbols
like resistors and capacitors are easy enough to sketch by hand, but something like
a dual gate MOSFET with diode protection can take some time to produce legibly.
Common connector types like the DB signal/power series and some RF kinds (BNC, SMA,
etc.) would be useful, as would a set of oft-used logic gates for the digital designers.
The set shown here in a 1953 edition of Radio-Electronics magazine includes a handful
of vacuum tube types which would have taken some time to draw by hand, and a few
"The demand for bandwidth has been increasing
continuously in the cellular world and there are no indications of it slowing down.
This is true in large public venues as well, such as arenas and stadiums, where
the fans require large bandwidths to communicate and send pictures / videos. Using
Lens Antennas in these scenarios not only increases cellular coverage and capacity
in venues, but it can do that at a lower cost than traditional methods with the
added advantage of improved aesthetics. The problem for venue owners and operators
is to satisfy the ever-increasing requirement for connectivity. There is an increased
need for lower latency as well with the introduction of live mobile gaming inside
venues. Lens Antennas can be deployed in such venues which have multi-radio..."
Albert Einstein published his paper on
Special Relativity in 1905 and on General Relativity in 1916. Since that time,
many experiments have been performed worldwide by scientists intent on both proving
and disproving Mr. Einstein. Laser and nuclear based timepieces have been improved
for precision and calculations refined to aid in the task. This 1959 Popular
Electronics magazine article reports on one of the first atomic clock experiments
used to test General Relativity. After more than 100 years, General Relativity stands
as originally presented. Even the rigors of quantum mechanics, which Einstein did
not embrace until much later in life, has not toppled its precepts...
Empower RF announces the production release
Model 2239 pulsed driver amplifier producing a minimum of 1 kW peak power.
The 2239 is an intelligent amplifier in a compact 3U rack compatible footprint with
features ideal for integrating into Magnetron, IOT, Klystron and TWT systems. The
amplifier is designed for 0 dBm input that is pulse modulated. A fast TTL gate
input is standard, and its use optional when complete shutoff of the output stage
is desired between pulses. Pulse capabilities include up to 20% duty cycles and
pulse widths as long as 500 μsec with up to 25 kHz PRF's. GaN on SiC devices
are used in a multistage class AB configuration. Full self-monitoring protection
is included and will self-protect with sudden open/short conditions and is tolerant
to VSWR up to 3:1...
Alliance Test Equipment sells
used / refurbished test
equipment and offers short- and long-term rentals. They also offer repair, maintenance
and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix,
Anritsu, Fluke, R&S and other major brands. A global organization with ability
to source hard to find equipment through our network of suppliers. Alliance Test
will purchase your excess test equipment in large or small lots. Blog posts offer
advice on application and use of a wide range of test equipment. Please visit Allied
Test Equipment today to see how they can help your project.
This first installment in a multi-part series
on magnetism appeared in the October 1947 issue of Radio-Craft magazine.
At the time, there was great interest in
magnetic tape and even magnetic wire recorders. Lots of articles were published
on the electronics and mechanics of recorders, but relatively few discussed the
physics of magnetics. Although the title says it is about permanent magnetic theory,
there is also a lot of information on electromagnets. Terms such as reluctivity,
magnetomotive force, magnetic flux, conductivity of electrical and magnetic circuits,
conductance, B-H curves, maxwells, oersteds, and gilberts are introduced, along
with some simple equations relating everything...
"Engineering students at the University of
Cincinnati are building tiny custom CubeSat
satellites to test the radiation shielding properties of carbon fiber material
and take high-resolution photos of the Great Lakes from space. LEOPARDsat-1 will
record how much radiation from space seeps through different thicknesses of carbon-polyethylene
samples. HABsat1 relies on an internal flywheel system in which motor-driven spinning
flywheels can orient a satellite on three axes..."
Empower RF Systems is a global leader in
power amplifier solutions. Empower RF Systems is an established and technologically
superior supplier of high power solid state RF & microwave amplifiers. Our offerings
include modules, intelligent rack-mount amplifiers, and multi-function RF Power
Amplifier solutions to 6 GHz in broadband and band specific designs. Output
power combinations range from tens of watts to multi-kilowatts. Unprecedented size,
weight and power reduction of our amplifiers is superior to anything in the market
at similar frequencies and power levels.
Proficiency in Morse code is no longer required
as part of obtaining an Amateur Radio license. A proposal to drop the 5 wpm requirement
was first floated by the FCC in 2005. It was actually at the request of the ARRL;
to wit, "In 2004, the League called on the FCC to create a new entry-level license,
reduce the number of actual license classes to three and drop the Morse code testing
requirement for all classes except for Amateur Extra." ARLB018 FCC Proposes Dropping
Morse Code Requirement Entirely Now, there is no code requirement for any license
class, not even the Amateur Extra. A lot of Hams are not happy about it, but times
have changed and the need for code proficiency just is not needed anymore because
of the plethora of communications formats available. No small part of the ARRL's
motivation for requesting that code proficiency be dropped...
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...
The eleventh hour of the eleventh day of
the eleventh month - November 11th, at 11:00 am - that is when the armistice (cease
fire) began in 1918, unofficially ending World War I. This music video
Veteran's Day tribute is by Canadian citizen
Terry Kelly. It was written after an experience he had on Veterans Day in 1999.
Terry went blind at an early age, but has excelled as an athlete and a musician.
"A Pittance of Time" is done in the finest Celtic tradition. Per the U.S. Department
of Veteran Affairs website: "World War I – known at the time as 'The Great War'
- officially ended when the Treaty of Versailles was signed on June 28, 1919, in
the Palace of Versailles outside the town of Versailles, France. However, fighting
ceased seven months earlier when an armistice, or temporary cessation of hostilities,
between the Allied nations and Germany went into effect on the eleventh hour of
the eleventh day of the eleventh month. For that reason, November 11, 1918, is generally
regarded as the end of 'the war to end all wars...'"
RF Superstore launched in 2017, marking
the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and
microwave Industry. Pasternack fundamentally changed the way RF components were
sold. Partner Jason Wright manages day-to-day operations, while working closely
with Mr. Pasternack to develop RF Superstore into a world class RF and
supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies,
surge protectors, attenuators. Items added daily. Free shipping on orders over $25.
We're leading the way again!
After getting out of the U.S. Air Force
in 1982, I was fortunate to get a job at the Oceanic Division of Westinghouse Electric
Corporation in Annapolis, Maryland. Most of the guys who worked in the area with
me were former electronics technicians from the armed forces. We spent most of our
days (and often evenings) building small quantity specialty systems for the U.S. Navy.
The facility was fairly small and was not set up for high volume production; that
was the purview of the much larger operation based adjacent to the Baltimore / Washington
International Airport (BWI), which built ground-based and airborne radar systems.
Whilst there, I did a lot of
wire-wrap assemblies that went into MIL-SPEC systems, primarily rack-mounted
equipment in helicopters and aboard ships deploying towed sonar systems. As such,
I received extensive training for performing soldering, wire-wrapping...
Gowanda Announces Expansion of
Its DYCO Electronics Facility
Gowanda Components Group is pleased to announce
the completion of a nearly 50%
expansion at its DYCO Electronics facility in Hornell, New York. The 12,000
sq. ft. expansion will help the company address market demand for its products,
enhance work flow and improve operational efficiency. "We manufacture custom components
and assemblies for the rail industry, so size and scale were important drivers for
this expansion," said Greg Georgek, President of DYCO Electronics. "In addition,
we've seen growth in our overall custom manufacturing business in recent years –
with projections for that to continue – as our customers have increased their outsourcing
of more assemblies to DYCO," Georgek added. DYCO engineers custom solutions for
aerospace, military, space, medical...
Since 1961, MECA
Electronics has designed and manufactured an extensive line of
RF & microwave components
for in-building, satellite, radar, radio, telemetry, mobile radio, aviation &
ATC. Attenuators, directional & hybrid couplers, isolators & circulators,
power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables.
MECA has long been the 'backbone' of high performance wired and air-interfaced networks
such as in-building applications, satellite communications, radar, radio communications,
telemetry applications, mobile radio, aviation & air traffic communications.
Axiom Test Equipment, an electronic test
equipment rental and sales company has published a new blog post entitled "Keep
the Light Shining on Solar Power Systems" that covers maintenance programs on
solar power systems in order to achieve optimum results. This maintenance can be
greatly simplified with the right test tools. Learn which components in any solar
power system that should be regularly tested as part of a maintenance program. In
general, maintenance should involve the main system parts like solar panels, energy
storage units, inverts, and their interconnections, and their price performance
parameters. Main test tools for checking solar power systems should provide measurements
of power, voltage, and current at maximum levels that exceed the performance limits
of the solar power system's components...
unijunction transistor (UJT), invented in 1953, was originally known as a "double-base
diode" and explains why to this day the terminals are labeled "E," "B1,' and B2."
It is commonly modeled as a diode connected between two resistors, with one resistor
being variable. As the name implies, unlike a bipolar junction transistor (BJT)
that is more familiar to most people and has two semiconductor junctions connected
to the base, a UJT has just one junction. As is explained in detail in this 1970
Popular Electronics article, the net effect of the UJT's arrangement is a region
of negative resistance which makes it good for use as an oscillator. In fact, the
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave filters,
diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity,
and waveguide designs, as well as state of the art high performance suspended substrate
models. Through a continuous process of research and development, they have established
a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop,
diplexer, and more. Established in 1979. Please contact Reactel today to see how
they might help your project.
A month before Bell Laboratories' announcement
of the transistor invention by Mssrs. Bardeen, Shockley and Brattain, Radio-Craft
magazine editor Hugo Gernsback published a piece extolling the virtues of a newly
microtube, aka a "rice-grain" tube. As connected as Gernsback was in the electronics
industry, it is doubtful he knew of the impending game-changing invention. Commercialization
of the transistor took a few years to get to the point where the devices could be
manufactured cheaply and reliably enough to begin being integrated (pun intended)
into products, so vacuum tubes still reigned for another decade or more. While the
microtubes were designed into such products as portable radios, hearing aids, and
other things in desperate need of size reduction, standard tubes continued to be
used in the majority of things...
Windfreak Technologies announces the availability
of the new
SynthUSB3 RF Signal Generator. The SynthUSB3 thumb drive sized RF Signal Generator
is designed for extremely high quality to cost ratio. These devices have set the
bar on microwave radio frequency generators for quality, size and price. As always,
our products are designed, manufactured and supported in the USA - and it arrives
already calibrated! Tune any frequency between 12.5 MHz and 6.4 GHz in
0.01 Hz resolution. Adjust calibrated amplitude in 0.2 dB resolution up
to +8 dBm and across more than 50 dB of range. 500 point frequency and
amplitude hop table. Expect excellent performance and high reliability
despite the SynthUSB3's low cost...
If this article had appeared in the New
York Times in the year 2020, its author, Glenn Ellsworth, would have been labeled
Denier!' Don't be confused by the word 'denier,' which most often prior to about
1999 was used to refer to a type of silver coin or a measure of fineness of silk
cloth. Today, it is seen most often as describing one who would deny something.
'Denyer' is the alternate spelling used by some authors to avoid confusion, and
since the level of spelling knowledge is so low, most people never notice. But,
I digress. The reason I bring up the point is because this article was published
in 1933, little more than three years after the Stock Market Crash of October 29,
1929 (aka 'Black Tuesday')...
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.
Jeffrey Kahler and Andreas Wien have an article
in Microwaves & RF magazine that shows how two disparate software programs
can be used together to design and
optimize a system segment consisting of the antenna and an associated planar filter.
"For many years, IMST has been in the business of producing expert 3D electromagnetic
(EM) simulation software. With its Empire XPU product, IMST emphasizes and focuses
on antenna design and optimization. Nuhertz Technologies has also been around for
many years, producing expert filter design software. And with its FilterSolutions
tool, the company focuses on accurate 3D planar design and optimization. Therefore,
it seems a natural fit for these two products to work together so that users can
take advantage of the best features of both. Specifically, IMST's
Empire XPU EM optimization process can be used
on planar designs created with Nuhertz's FilterSolutions..."
Electro-Photonics is a global supplier of
RF & Microwave components.
Their products include SMT hybrid and directional couplers, wire bondable passive
components, mounting tabs, filters, transmission lines, and very useful test boards
for evaluating components (spiral inductors, single-layer capacitors). The Electro-Photonics
team can support your small R&D design requirements with RF & Microwave
test fixtures and save you valuable design and characterization time. Please take
a moment to visit Electro-Photonics' website and see how your project might benefit.
Famous Engineers & Scientists crossword puzzle took a long time to make
because of all the names that I managed to squeeze into the matrix. The way this
one works is the person's first initial and completely spelled-out last name, indicated
by (FI+LN) in the clue, is used as the answer. For instance, filter transfer function
developer Stephen Butterworth would be written as SBUTTERWORTH. There are at least
sixteen names here There are at least sixteen names here with which you should be
familiar. Good luck!