See Page 1 |
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5 | of the August 2020 homepage archives. Friday 21
 Just as the title of this installment of
Mac's Service Shop, "A Typical Day in the Shop," suggests, the
story is a recollection of the kinds of scenarios that would found in an ordinary
shift in an electronics service business in the mid 1950's. Vacuum tubes were the
norm of the day, as were discrete leaded components and a rat's nest of wires running
from solder lug to solder lug. Printed circuit boards were beginning to appear in
commercial products, but mostly existed in specialty defense and aerospace applications.
You might wonder how many different ways could there be for simple circuits like
biasing and heater element lighting, but some pretty imaginative variations made
their way into radios, television, record players, and tape decks, and often times
that made a serviceman's life heck. Such was the case here as über-owner-technician
Mac admonishes sidekick Barney for not taking time...
 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.
 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 (of course a gratuity will be graciously
accepted). 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 ...
 "Researchers from Drexel University have
discovered a two-dimensional material that has the ability to block electromagnetic
interference. Drexel University The material comes from a two-dimensional family
known as
MXenes. These materials were first produced back in 2011 at Drexel
University. Since then, researchers have discovered remarkable properties in many
of these two-dimensional materials - and this new discovery could prove to be one
of the most exciting yet. The material is known as titanium carbonitride. This discovery
breaks all the barriers that existed in the electromagnetic shielding field. It
not only reveals a shielding material that works better than copper, but it also
shows an exciting, new physics emerging, as we see discrete two-dimensional materials
interact with electromagnetic radiation in a different way than bulk metals..."
 The old adage about a picture being worth
a thousand words is still true today, even in the Information Age in which we live.
A lot of people, especially those new to the field of electronics, struggle with
the
concept of decibels as applied to power and voltage (and to a
lesser degree current). A plethora of computer, browser, and phone app programs
are available to make individual, specific conversions, but what has been learned
about the fundamental relationship? A nomograph is still one of the best tools both
for teaching and performing conversions. This article that discusses properly matching
impedances of amplification stages includes a nice nomograph...
 EDN has published the results of their 2020
"Mind of the Engineer" survey. It reflects changes in attitudes
and workplace preferences in this era of the Wuhan Virus (aka COVID-19). Many engineers
- and other workers - are discovering that they really like working remotely from
home. Of course some jobs require a physical presence at an office building, but
a lot of engineers are setting up labs in their homes where possible. "What's on
the design engineer's mind in 2020, the year pundits claim will change the workplace
forever with the option to work remotely during the COVID-19 pandemic? The electronic
design arena is already starting to witness the change, as corroborated in the latest
'Mind of the Engineer' survey carried out by AspenCore, the parent company of EDN.
For instance, while most engineers prefer to conduct circuit design..."
 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 are serviced around the world. Please take a couple minutes
to visit their website and see how IPP can help you today.
Thursday 20
 If you have never read the story of
Lee de Forest's journey from initial experiments to finally achieving
success with his amplifying vacuum tube, the Audion, then you might want to take
a few minutes to look over this article. It was published in a 1947 issue of
Radio-Craft magazine as part of the 40th anniversary of the invention that
changed the electronics world. With so many other things which are nowadays very
commonplace, we tend to not think about or appreciate the ingenuity and effort that
went into them. It is one thing to make incremental improvements in an existing
technology, but to conceive of and created an entirely new realm of science is quite
another. As with Albert Einstein's relativity and Robert Goddard's liquid-fueled
rockets, and the Wright brothers' powered aeroplane...
 TotalTemp Technologies is expanding its offerings
to include more products such as custom
wide range temperature chambers. Featured here is the model C230
temperature chamber with custom apertures on four sides and +325°C to -160°C temperature
range. It features time tested designs and the award winning synergy Nano temperature
controller. Meet your custom requirements in a better way than with off the shelf
solutions. Two year warranties and accessible knowledgeable support before and after
the sale. TotalTemp also offers a new product line of refrigerated custom thermal
platforms capable of -70°C without the need for expendable coolants...
 "U.S. Special Operations Command could order
up to $172M worth of
inflatable satellite communications terminals under a new five-year
contract with GATR Technologies, a subsidiary of Cubic Corp. By using an inflatable
radome, GATR Technologies' antennas are designed to be ultra-portable and easy to
set up. The smaller version can be set up in less than 20 minutes, while the larger
can be set up in less than 30 minutes. Consisting of five one-year ordering periods,
the indefinite delivery, indefinite quantity contract provides for the procurement
of 1.2-meter and 2.4-meter inflatable satellite communications terminals and related
equipment. The contract was issued as a Phase III Small Business Innovation Research
award by USSOCOM..."
 This "Carl and Jerry" episode entitled "Extracurricular Education" is a bit far-fetched compared to the
typical storyline, but it does illustrate how when you are desperate to get out
a distress signal, a little technical knowledge and having a knack for improvisation
can save the day. Back then there were probably a lot more people sitting around
their radios or TVs who might have heard the SOS message and actually know what
it was. I am no Morse code master, but anytime I hear the familiar di-di-dit dah-dah-dah
di-di-dit (··· --- ···) cadence in a movie or anywhere else, my attention tunes
into it like a mother recognizes her baby's cry in a noisy room. Interestingly,
seat belts are mentioned in this 1963 issue of Popular Electronics magazine. Ford
began installing them in 1955 as an option...
 ConductRF offers RF Engineers a large selection
of
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
solutions...
 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.
 This
Analog & RF Filter Basics Quiz targets those of you who are
relative newcomers to the world of radio frequency (RF) electronics, but seasoned
vets are welcome to give it a go as well. It addresses frequency response and physical
construction. Images were obtained from Anatech Electronics documents entitled "Guideline
for Choosing RF and Microwave Products" and "Understanding Filter Types and Their
Characteristics." API Technologies' "RF & Microwave Filters," is also referenced...
 Modelithics, is pleased to announce the release
of version 20.4 of the COMPLETE+3D Library for use with
Ansys HFSS. The library contains over 325 highly scalable Microwave
Global Models™ for capacitor, inductor, and resistor families from many popular
vendors, plus a collection of nearly 300 Modelithics' 3D geometry models for inductors,
capacitors, filters, packages and connectors. Version 20.4 adds five new part value-,
pad-, and substrate scalable models and over seventy new full wave 3D electromagnetic
models. New scalable circuit models include a new model for Coilcraft's 0402DC inductor
series, Johanson's L-14C and L-14W inductor series, and Vishay's CRCW1206 resistor
series. New 3D EM models are available for Mini-Circuits' HFCN-740+, HFCN-880+,
and HFCN-2700+ filter series...
 "In novel materials known as
topological insulators, electricity or light can flow around corners
and defects with virtually no losses. All topological insulators produced so far
are comprised of an insulating bulk and perfectly conductive edges. Now scientists
have found - at least in theory - that fractal topological insulators could possibly
be made up only of edges, with no bulk at all. Topology is the branch of mathematics
that explores what aspects of shapes can survive deformation. For example, an object
shaped like a doughnut can get deformed into the shape of a mug, with the doughnut's
hole forming the hole in the cup's handle, but it could not get pushed or pulled
into a shape that lacked a hole..."
 While company branding and the user interface
have changed over the years since
AppCAD first
appeared on the Hewlett Packard (HP) website, it is still as handy a desktop tool
as ever. The most recent incarnation was provided by Avago Technologies, which bought
Broadcom in 2015 and then adopted its name. You can now download a free copy of
AppCAD from the Broadcom website. Rather than do an extensive write-up about all
the calculation screens in AppCAD, I've posted a sampling of screen shots. Amongst
them are a Smith chart s-parameter plotter, a lumped element balun designer, a microstrip
calculator, a mixer spurious product calculator, and thermal dissipation calculator...
 Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military,
commercial, aerospace and defense, and industrial applications up to 40 GHz.
The AE4570-5080DB5468 passes the frequency bands of 4390-4750 MHz and 4900-5260 MHz.
Insertion loss within the pass bands is less that 1 dB and an isolation between
the bands of more than 70 dB. The duplexer can handle powers up to 50 watts
and can be fitted with either SMA, N type or a combination of both. The TCAS 1090
MHz is a low profile SMT type Ceramic Band Pass Filter has a 1 dB BW of 10 MHz,
passing...
 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.
Tuesday 18
 Earth-Moon-Earth (EME) communications have
been used by amateur radio operators for a few decades now, made possible by more
capable transmitters and receivers as well as digital encoding which facilitates
operation closer to the noise floor. EME is regarded largely as a novelty branch
of Ham radio since relatively few people are set up to exploit it. In 1946, the
U.S. Army Signal Corps created "Project Diana," named for the Roman moon goddess
Diana, as an experimental exercise to bounce radar signals off the Moon and receive
the reflected signals. It was the first attempt at radar astronomy and was the first
time a terrestrial radio signal was bounced off another celestial body. Once artificial
satellites were orbiting in the late 1950's, Hams and other entities were encouraged
to detect and track orbits and signal transmission properties - including frequency
and power - to aid government engineers and scientists in determining stability
(electrical and mechanical), speed, rotation, altitude, path, atmospheric and cosmological
noise sources, and other parameters...
 LadyBug Technologies' line of power sensors
is now supported in Copper Mountain Technologies S2VNA software. Starting with
S2VNA SW v.20.3.1, LadyBug power sensors LB4xx, LB5xx, and LB59xx
can be used for power calibration. LadyBug True RMS Average Power Sensors deliver
reliable, accurate, power measurements for CW, Pulse, and modulated signals. These
diode-based sensors feature a wide dynamic range and a great VSWR. The optional
external triggering input feature can be used without any external components. Recorder
and Trigger outputs are also available. LadyBug's patented NoZero NoCal technology
makes these sensors ideal for calibration systems, automated test stations and other
embedded applications...
 "The first European satellite that is capable
of being completely repurposed after launch and developed within an ESA Partnership
Project - Quantum - has concluded its radio-frequency tests at a specialized facility
in Toulouse (France). Quantum is the first ever
software-defined satellite, preparing the way for the next generation
of telecommunication satellites that can be reprogrammed in orbit. It offers unprecedented
in-orbit reconfigurability in coverage, frequency and power, which allows for complete
mission rehauls including changes in orbital position. Engineers involved in the
Quantum Partnership Project from manufacturer Airbus, operator Eutelsat and ESA
(European Space Agency) have developed new working practices that have enabled them
to keep working during the coronavirus pandemic. This ensures that the satellite
will be fully ready to launch later in the year..."
 Here is Part 1 of a three-part article on
attenuator pad and impedance matching articles that appeared in
Radio-Craft magazine. Although the focus is on audio frequencies, the principles
apply in general. It is interesting to read about wavelengths expressed in units
of miles versus feet and meters like we are used to seeing for radio frequencies.
Keep in mind that most of the decibel formulas used here are for voltage and not
for power. As a reminder, the decibel representation of a ratio is always 10 * log10 (x).
If you have a voltage ratio of V1/V2 = 0.5, then 10 * log10 (0.5) = -3.01 dB.
If you have a power ratio of P1/P2 = 0.5, then 10 * log10 (0.5) = -3.01 dB.
Does that mean that -3.01 dB of voltage attenuation is the same as 3.01 dB
of power attenuation? Confusingly, no...
 Exodus Advanced Communications' model
AMP2070C is designed for broadband EMI/RFI, laboratory, communications
and EW applications. Class A/AB linear design for all modulations & industry
standards. Covers 700 MHz – 6.0 GHz, produces 100 W Minimum, 50 W
P1dB, with a minimum 50 dB Gain. Excellent gain flatness, optional monitoring
parameters for forward/reflected power, voltage, current and temperature sensing
for superb reliability and ruggedness. Integrated in our compact 3U chassis weighing <25 kg.
Suitable for CW, pulse and all single channel modulation standards. Built-in protection
circuits...
 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."
Monday 17
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols 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). Symbols 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...
 For some reason the "too clever by half"
saying (but not in an insulting way) comes to mind when reading this article about
color TV from a 1951 issue of Radio & Television News magazine. The
color television industry was still searching for an acceptable
standard broadcast format when this was written, and the electromechanical contraption
was not considered too elaborate considering the original color TV schemes were
all a conglomeration of whirling colored wheels, light sources, and photodetectors
coupled with accommodating timing and intensity signals. Because there was not agreement
on what the final commercial broadcast signal format would look like, there was
not a lot of motivation for test equipment makers to invest time and money into
providing gear for research and development laboratories. Do you remember the ads
for the screen that installed on the front of a TV set to convert black and white
(B&W) to color...
 TotalTemp Technologies has added
hot-only models to the product line of wide range thermal platforms
for solder processes and testing. 300 °C and 400 °C models have great
pricing, safety and the same flexibility of hot/cold models. Conductive aluminum
surface is superior to radiant heat models in speed and control accuracy. The compact,
full-featured HSD14 heat-only thermal platform provides a heated surface area of
14 sq.in. and the HSD14 heat-only thermal platform provides a heated surface
area of 144 sq.in. Our Watlow EZ-ZONE PM temperature controller is a programmable
thermal platform interface with large, easy to read characters with fail-safe and
limit setting capability...
 "To enable data transmission speeds that
surpass the 5th Generation (5G) standards for telecommunications, scientists from
anyang Technological University, Singapore (NTU Singapore) and Osaka University
in Japan have built a new chip using a concept called
photonic topological insulators. Published recently in Nature
Photonics, the researchers showed that their chip can transmit terahertz (THz) waves
resulting in a data rate of 11 Gigabits per second (Gbit/s), which is capable of
supporting real-time streaming of 4K high-definition video, and exceeds the hitherto
theoretical limit of 10 Gbit/s for 5G wireless communications. THz waves are part
of the electromagnetic spectrum, in between infrared light waves and microwaves,
and have been touted as the next frontier of high-speed wireless communications..."
 Early investigations into
RF signal atmospheric "ducting" was reported in this 1956-era
article in Popular Electronics. Ducting effects were first noticed during World
War II when Nazi broadcasts from occupied Paris were received occasionally
in London. Scientists discovered that a small change in the humidity of the air
near the surface has the effect of trapping radio waves, a trapping process dubbed
"ducting." These waves are conducted as if they were inside of a metallic waveguide.
Research by the U.S. Army Signal Corps determined a sudden temperature rise at around
50 to 200 feet above the surface appears to have the strongest effect...
 RF Cafe visitor Brad Baker, now retired,
sent me this paper entitled, "Tunable Constant Q Band-Pass Filter Design Using q and k Values,"
which he wrote about work he did waaaaay back in the last century before computer
simulation and optimization was available on every desktop. Says Brad, "Attached
is a filter design I did in '86. I got a job working for a small land mobile radio
company as an RF engineer and my first assignment was to design a tunable band-pass
filter that tuned from 29 MHz to 59 MHz. I had been out of school for about
two years at this point. I had quite a bit of design experience during my co-op
semesters doing some RF and baseband filters, IF / analog / baseband amplifiers
but nothing like this. I can tell you I was sweating it a little bit."
 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. Please
visit Allied Test Equipment today to see how they can help your project.
Sunday 16
 August 16th's custom
Electrical Engineering themed crossword puzzle contains only only
words (1,000s of them) from my custom-created lexicon related to engineering, science,
mathematics, chemistry, physics, astronomy, etc. You will never find among the words
names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything
of the sort. You might, however, find someone or something in the otherwise excluded
list directly related to this puzzle's technology theme, such as Hedy Lamarr or
the Bikini Atoll, respectively. The technically inclined cruciverbalists amongst
us will appreciate the effort.
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.
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