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4 of the October 2021 homepage
archives. Thursday the 30th
 Plenty of single-layer coil (inductor) winding
calculators, charts, and nomographs can be found on the World Wide Web, but finding
one for multi-layer coils is a bit harder- until now. Actually, this
Multi-Layer Coil Calculator Nomograph appeared in a 1955 issue of Radio &
Television News magazine. It was an era long before personal calculators, computers,
and smartphones, when long-hand written-out problem solving was the norm, and slide
rules made such tasks easier for those fortunate enough to know how to work one.
I did a little head scratching upon encountering the term "no. 27 d.c.c. wire,"
not being familiar with the "d.c.c." part. A little research turned up that it means
"double cotton covered" for insulation, and there was also "s.c.c." for single cotton
covered. Belden and Alpha used to make it. Enamel-covered wire is now used for winding
coils and transformers. As you might expect...
 PCB manufacturer TechnoTronix has a blog
post you might find useful entitled "Rogers
PCB Vs FR4 PCB – What is the Difference?" It begins: "In the world of hi-tech
gadgets, medical equipment, and Industrial Machines, the performance of any product
depends mainly on the quality of its PCB design. Though there are multiple aspects
to be considered while designing a PCB, our focus here is to identify the right
PCB material which is also known as Substrate. Substrates are the dielectric sheets
that hold the components and traces of a design. Selecting the right substrate material
for a specific application is the key aspect of PCB design. To decide which substrate
works best for any given application, we need to know the salient features of all
the materials available on the market. The materials offered include FR1 to FR6,
CEM1 to CEM5, insulated metal substrates..."
 KR Electronics designs and manufactures high
quality filters for both the commercial and military markets. KR Electronics is
ISO 9001:2008 certified. KR Electronics manufactures all filter types and individually
synthesizes filters for special applications. State of the art computer synthesis,
analysis and test methods are used to meet the most challenging specifications.
On the following pages you will find more information on some of our products. The
products shown are a small representation of the thousands of filters designed and
manufactured. Choose from one of our standard filters or let us modify or design
a filter to meet your exact requirements. Data sheets for off-the-shelf filters
are available online...
 Here is a little levity from the "Hobnobbing
with Harbaugh" series of comics that appeared in Popular Electronics
magazine. Unfortunately, none of the "The 5 Most Wanted Household Inventions" have
come to full fruition in the marketplace yet, although the Conversation Jammer can
be found on the Internet in various unofficial forms. Personal computers were a
pipe dream in 1963, but nowadays we do have software like TurboTax to take care
of filing taxes, although you still can't simply dump all your receipts into a bin
and have it work. Flat-fixing robots might not be needed in a few years as tubeless,
airless tires hit the road. Alarm clock vaporizers are not Star Trek phaser-like
devices yet, but the same effect can be affected with a low-tech hammer, or a shoe...
 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 ...
 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.
Wednesday the 29th
 I have quoted previously a saying which my
earliest mentor, Westinghouse Oceanic Division über engineer Jim Wilson, liked to
utter: "If
the tool ain't right, the guy ain't bright." The meaning, of course, is that
using the wrong tool for the job can have results ranging from exasperating and
time-consuming to downright dangerous. Owner and proprietor Mac McGregor touches
on the theme when addressing service shop technician Barney Jameson regarding bad
practices that have built up over time and needed to be corrected. He admonished
himself as well as Barney for allowing the situation to get so far out of hand.
As always, author John Frye's goal in writing these technodramas was to both entertain
and to teach. Anyone who has put in much time in a workshop can relate to how taking
time from the business at hand to keep a neat and orderly environment is a difficult
discipline to maintain. Some people joking...
 "Carbon fiber reinforced polymer composite
structures are serving an increasingly important role in aerospace, infrastructure,
energy generation, and transportation. Yet, the electrical behavior of a composite
is challenging to measure or predict because of the electrical conductivity of
constituent carbon fibers and the composite's complex hierarchical microstructure.
In Journal of Applied Physics, researchers from the University of Illinois at Urbana-Champaign
report the first direct measurement of the transverse electrical resistivity of
a single carbon fiber. The researchers combined a precise sample preparation with
a technique called the van der Pauw method to accomplish this challenging measurement.
"Our experiments confirm that the electrical properties measured..."
 Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his September 2021 newsletter that
features his short op-ed entitled "5G:
Will Millimeter Waves Be High Enough?," where he notes the technical difficulties
being experienced with components and operational environments in the mm-wave realm,
and that life in the THz spectrum will be even more challenging - perhaps even impossible
for general use. As we know from Friis equation, electromagnetic power levels drop
proportional to the square of distance (6 dB per doubled distance), but in
the THz region atmospheric absorption comes into play as physical molecules resonate
at specific wavelengths, further decreasing received power...
 Part 4 of Lou Frenzel's series on impedance
matching, entitled "Automatic
Impedance Matching in RF Design," is now available. He discusses schemes for
self-tuning antenna interfaces. As most Amateur radio enthusiasts know, there are
plenty of self-tuning units available - at least for Ham bands (see
DX Engineering for manufacturers). Some transmitters and transceivers have
auto-tuning built in so separate units are not needed except for extreme mismatches
- which can occur when a multiband antenna is either poorly designed or pushed beyond
its intended frequency range. Lou begins: "Impedance (Z) matching is an essential
part of most RF circuit design. Regardless of what you’re designing, getting as
much power to a load is a top target. Impedances must be matched to transfer the
maximum amount of signal power between stages. And in power amplifiers (PAs), impedance
matching is critical to getting the maximum power to the final load and maintaining
PA linearity..."
 As with most hobby and how-to magazines,
QST has had a long-running monthly column featuring handy tips from readers
and sometimes from the column editor's (currently Steve Sant Andrea) own experiences.
It has taken various names over the years such as "Gimmicks and Gadgets," "Hints &
Kinks, "and now "Hints & Hacks." Steve retired from the column after 2017, and
now there is no byline accompanying it. This installment from the December 1966
QST presents a short introduction to a
VHF "Lazy-H"
antenna for mounting in the attic (outdoor restrictions were common even half
a century ago). It is of simple construction using lamp cord in the configuration
and element lengths given - still useful in 2021...
 RF Cascade Workbook 2018 is the next phase in the evolution
of RF Cafe's long-running series, RF Cascade Workbook. Chances are you
have never used a spreadsheet quite like this (click here for screen capture). 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...
 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
RF today.
Tuesday the 28th
 It is interesting how over time the common
spelling of names of countries change. Sometimes is is merely a difference in the
way we in America spell a word versus in Europe; e.g., "color" vs. "colour" and
"aluminum" vs. aluminium." In the "European
Report" column of this 1949 issue of Radio-Electronics magazine, what
we spell as "Romania" today is spelled "Roumania." Aside from that, a fairly uncommon
unit of loudness (sound pressure) is mentioned - the "phon" - which is a logarithmic
scale of the more familiar linear scale "sone." Note also at the time a person who
watches television is a "televiewer" and the thing he/she watches is a "televiser."
Finally, a bit about the ever-present battle against electromagnetic interference
(aka "noise") both of the natural (QRN) and manmade (QRM) nature. No matter how
high in frequency we manage to go, the spectrum will always eventually get crowded...
 TotalTemp Technologies' John Booher
is featured in Evaluation Engineering's Special Report: "Power
Semiconductor Testing." Also quoted are Tektronix / Keithley Instruments' Mark
Cejer, Teradyne's Seth Prentice, and Rohde & Schwarz's John Lewis, all
of whose companies make special test equipment and environmental control fixtures
for testing power semiconductors. It begins: "Manufacturers in the power semiconductor
industry have been tackling challenges of performance, reliability, and lowering
the cost of high-power devices for decades. More recently, boosting energy efficiency
has taken on a higher priority. As semiconductor technology has advanced, such devices
can now function with higher power, voltage, and frequency, and electronic testing
vendors now must face the challenge of adapting testing needs for multiple versions
of such technologies..."
 "Part of the Novel Weapons Programme (NWP),
the announcement will see significant investment in the development of
directed energy engineers including around 30 new jobs to be created at Thales'
site in Belfast, Northern Ireland. Three DEW capability demonstrators will be developed
as part of the investment. The first laser demonstrator (LDEW), led by Thales, will
undergo user testing onboard a Royal Navy Type 23 frigate by detecting, tracking,
engaging and countering Unmanned Aerial Vehicles (UAVs). Partners will include BAE
Systems, Chess Dynamics, Vision4CE and IPG. The British Army's Wolfhound armoured
vehicle will host another laser demonstrator..."
 If you are an
audiophile, you probably have spent a lot of effort setting up your home entertainment
system, car system, and maybe even your portable music player. You know all about
how to select speakers, where to place them, the kind of wire and connectors to
use, treble, midtone, and bass equalization. You know what you like, but the way
you perceive sounds is not the way many other people do. Even if your hearing follows
a "normal" response curve per standardized audio tests, personal preferences vary
widely in part because the way brains are wired (speed of sound processing, preferred
musical style, state of mind - maybe you're insane) and in part because of the impact
of sound waves upon your body (soft tissue and bone pressure wave conduction, clothing
worn). Pitch, timbre, tone, and loudness has been extensively studied and quantified...
 Infographic, courtesy of Windfreak Technologies'
David Goins, "The Ins and Outs of Radio Frequency." "Radio frequencies are
used in a wide range of items, but most people do not understand how they work or
are used in our daily lives. A radio frequency is a type of electromagnetic energy
and is measured in hertz, and it is used by radars, radios, televisions, microwaves,
GPS, cells phones, and satellites. When you are buying these types of products,
you should look for items that come with warranties, are high in quality, and have
the required functionality. Take the time to do your research to learn more about
how radio frequencies work and how much of an impact it has in daily life activities..."
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils 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). Stencils 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...
 Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today!
Monday the 27th
 This
is pretty cool. A recruitment ad for the U.S. Air Force appeared in the March 1961
issue of American Modeler magazine showing the type of
precision approach radar (PAR) that I worked on while in the service. It was
part of the AN/MPN-14 Landing Control Central system which was a mobile combat unit
consisting of airport surveillance radar (ASR) and PAR primary radar, a TPX-42 Identification
Friend or Foe (IFF) synthetic radar, an AN/GPA-131 data mapper, and AN/ARC-? VHF/UHF
radios. Alignment of the display for glide slope (top) and course line (bottom),
and mile markers, was a complicated procedure involving twisting multiple interdependent
control knobs until the sweeps met with a template. It was not a raster type sweep
like a vintage CRT television, but like an old fashioned oscilloscope sweep instead
where x-y data was fed to the deflection coils...
 RIGOL Technologies is transforming the Test
and Measurement Industry. Our premium line of products includes digital and mixed
signal oscilloscopes, spectrum analyzers, function / arbitrary waveform generators,
programmable power supplies and loads, digital multimeters, data acquisition systems,
and application software. Our test solutions combine uncompromised product performance,
quality, and advanced product features; all delivered at extremely attractive price
points. This combination provides our customers with unprecedented value for their
investment, reduces their overall cost of test, and helps speed time to completion
of their designs or projects.
 everything PE - www.everythingPE.com
is a new website that has been developed for the Power Electronics industry. The
power electronics industry plays an important role in various applications that
provide compact and high-efficient solutions to power conversion. Demand for power
electronics is further driven by an increase in their usage in several applications
such as smart vehicles, wireless products, industrial motor drivers, electric grid
stabilization, and consumer electronics. everything PE has been developed to meet
the growing demands of the power electronics industry and to help solve the problems
that engineers face while searching for application-specific products. everything PE
- www.everythingPE.com keeps engineers up to date with the latest news, products...
 RF Cafe visitor Terry W. wrote to me
about a topic that ended up mentioning RCA's vacuum tube voltmeter (VTVM) known
as the
VoltOhmyst. VTVMs were the era's high-input-impedance multimeter, before FETs
came on the scene. The higher a meter's input impedance, the less it loads the circuit
under test. Any meter connected across a circuit appears as a parallel load to the
source, so the closer it is to an open circuit, the better. Terry mentioned how
the VoltOhmyst was a key component on test benches of many professionals. You can
still buy various models of the VoltOhmyst on eBay. This 1959 Popular Electronics
magazine article reports on the kit version which at the time used vacuum tubes.
Later models sold into the 1970s were solid state. The printed circuit board in
the 1959 model was very avant-garde in a time when point-to-point was still the
norm...
 New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 16,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. I also re-broadcast homepage
items on LinkedIn. If you need your company news to be seen, RF Cafe is the
place to be.
 ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies for
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!
Sunday the 26th
 This
Radio Technology Theme crossword puzzle for September 26th contains only words
and clues related to engineering, mathematics, chemistry, physics, and other technical
words. As always, this crossword 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 (e.g., Hedy Lamarr or the Bikini Atoll).
The technically inclined cruciverbalists amongst us will appreciate the effort.
Enjoy!
 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.
Friday the 24th
 In the 1940s, the LORAN (LOng RAnge Navigation)
system, originally designed at the Massachusetts of Technology (MIT), was considered
as significant of a breakthrough technology as GPS (Global Positioning System) was
when it became operational in the 1990s. Unlike with GPS and its P (precision) and
C/A (coarse/acquisition) codes for military and civilian use, respectively, the
full accuracy capability of LORAN was available from the start to both military
and civilian users. There were no encoded signals to discriminate between users.
Not until the year 2000 did civilian use gain access to full GPS accuracy. As would
be expected, LORAN underwent a number of improvements over the years, and evolved
into LORAN-C, which offered greater range and accuracy...
 Planar Monolithic Industries (PMI) recently
introduced four new products in their extensive line of
RF and microwave components. Included are a 0.15 to 5.0 GHz Limiter, a 2.0 to
18.0 GHz SP2T Absorptive Switch , a 500 MHz to 40 GHz Low Noise Amplifier, and a
12 GHz Temperature Compensated Dielectric Resonator Oscillator. Planar Monolithics
provides its unique products for applications in space, military, communications,
telecommunications, commercial, and consumer electronics systems. Contact PMI today
for more information...
"Carbon fiber reinforced polymer composite
structures are serving an increasingly important role in aerospace, infrastructure,
energy generation, and transportation. Yet, the electrical behavior of a composite
is challenging to measure or predict because of the electrical conductivity of
constituent carbon fibers and the composite's complex hierarchical microstructure.
In Journal of Applied Physics, researchers from the University of Illinois at Urbana-Champaign
report the first direct measurement of the transverse electrical resistivity of
a single carbon fiber. The researchers combined a precise sample preparation with
a technique called the van der Pauw method to accomplish this challenging measurement.
"Our experiments confirm that the electrical properties measured..."
 "The
2021 Salary & Career Survey, presented by Electronic Design, will take the
pulse of manufacturing leaders like you at the end of another challenging year.
The 2021 Salary & Career Survey will go beyond the numbers to ask about how
manufacturing is building a recovery in light of COVID-19 restrictions and worker
shortages. 'This survey of industry professionals is part of a continuing effort
by Electronic Design to survey the industry and gather the thoughts and views of
the people who work every day to improve operational productivity, safety and effectiveness,'
said Bill Wong, senior content director for Machine Design. “We'll be using the
data throughout the year to look at specific segments of the market and try to understand
and then inform our global audience about trends in manufacturing..."
 Image response, harmonic of the IF, direct
IF response, harmonics of the oscillator, combination of the IF, heterodyne oscillator
radiation, cross modulation within the receiver, cross modulation external to the
receiver, same channel beat, adjacent channel beat and "monkey
chatter" are all sources of radio interference addressed in this article that
appeared in a 1946 edition of Radio News. I don't know about you, but I've never
heard of the term 'monkey chatter.' According to the troubleshooting table it is,
"Unintelligible modulation superimposed upon desired station, having the character
of 'inverted speech'." Recommendations on how to mitigate "monkey speech" are provided...
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 ...
 Atenlab has been operating in Taiwan for
more than a decade, and has sold and installed hundreds chambers around the world.
Holistic, affordable Over-the-Air
(OTA) measurement systems perform comprehensive measurement and test in a controlled
environment. Compact Antenna Test Range (CATR) with one-touch operation supports
multiple systems - 2G, 3G, 4G, 5G - and major instrument brands. [M]ulti-probe OTA
measurement systems offer reduced time measurements over single-probe systems.
Thursday the 23rd
 The
Belmont Model 6D111 tabletop radio must have been very popular because there
are many of them still available - in both white and brown - for purchase on eBay.
Since radios, televisions, phonographs, tape players, etc. were considered serviceable
items back in the vacuum tube days, magazine such as Radio-Craft often
published Radio Service Data Sheets with basic specifications, alignment information,
and a schematic. Companies like Sams Photofact sold more comprehensive data packets,
but these abbreviated datasheets were convenient for do-it-yourselfers and smaller
service shops that could not afford a subscription to Sams. Since there are still
many people who restore these vintage radios, I post these Radio Data Sheets to
help preserve the history...
 Skyworks is pleased to introduce its SKYA21038,
SKYA21039, SKYA21040 and SKYA21041
switches and front-end modules (FEMs) for automotive, cellular compensator and
cellular telematics. The SKYA21038 is a single-pole, double-throw (SPDT) switch
intended for mode switching in WLAN applications. Using advanced switching technologies,
the SKYA21038 maintains low insertion loss and high isolation for all switching
paths The high-linearity performance and low insertion loss achieved by the switch
make it an ideal choice for low-power transmit/receive applications...
 "Forefront RF, a Cambridge-based fabless
semiconductor company, is set to change the way global smartphones, wearables, and
IoT devices are designed. They have developed a chip that enables connected devices
to operate across the increasingly wide range of 3G to 6G mobile telephony frequency
bands. Forefront RF's cancellation technology redesigns the radio frequency (RF)
system in a wireless device, enabling manufacturers to simplify the design and delivery
of
frequency agnostic products, whilst reducing cost and supply chain waste. Forefront
RF was founded in 2020 by Dr Leo Laughlin whose academic work in this field is widely
cited, together with Julian Hildersley who brings 30 years of experience in the
development and marketing of ground-breaking RF mobile phone technologies..."
 Triad RF Systems has entered into a partnership
with Mobilicom, an end-to-end provider of cybersecurity and smart solutions for
drones, robotics & autonomous platforms. The partnership will initially provide
an
integrated product line featuring Mobilicom's multi-function radios (MCU product
family) coupled with Triad's high-power radio solutions and create a new product
line for sale and distribution by both companies. The product line will include
Mobilicom's secure Mobile MESH technology and its ICE Cybersecurity Suite with Triad's
smart RF amplifiers to provide the most cost effective and efficient fully integrated
amplified MIMO (multi-input and multi-output) radios, on the market, for MESH network
communications. Targeted at suppliers and manufacturers in the rapidly expanding
unmanned / autonomous systems...
 Here is a unique quiz by überquizmaker Robert
Balin, from Popular Electronics.
Names of components we use in electronics - particularly ones that have been
around for a long time - were given nomenclature that come from the animal kingdom
because they happen to resemble one in some way. Probably the most familiar are
examples like the alligator clip, pigtails, and rabbit ears - although the younger
you are the less likely you might be to have heard the names. Recent election results
in Colorado and Oregon may give a resurgence in popularity of and familiarity with
alligator clips by potheads...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils 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). Stencils 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...
 Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners
(hence 'Triad') with over 40 years of accumulated
knowledge of what is required to design, manufacture, market, sell and service RF/Microwave
amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating
amplifiers are available, in formats including tower mount, benchtop, rack mount,
and chassis mount. "We view Triad more as a technology partner than a vendor for
our line-of-sight communications product line." Please check to see how they can
help your project.
Wednesday the 22nd
 A month prior to this
Metal Lens news item appearing in Radio-Craft magazine (May 1946),
the inventor, Bell Telephone Laboratories, ran a full-page advertisement boasting
of their accomplishment. As mentioned in my write-up, it is sort of akin to the
Osgood optical lens used in lighthouses. Imagine performing the mathematical calculations
required to design that thing using a slide rule! Also reported here was the resumption
of regular television broadcasting in England by the BBC after war-caused alterations
in programming. Compared to the capability, compactness, and weight of modern night
vision equipment available today (see examples on Amazon for <$200), the "Snooperscope"
presented here is a very crude device. It relies on a powerful infrared light source...
 This vintage
Heathkit IM-2420, 512 MHz Benchtop Portable Frequency Counter kit is one
of the latest unbuilt Heathkit kits which appeared on eBay. I have been saving the
images in order to preserve the history (see image below). The constantly growing
list is at the lower right. One of the first instances I could find for IM-2420
being offered for sale was in the Winter 1981 Heathkit catalog, at a cost of $239.95
($754.51 in 2021 money per the BLS) as a kit or $299.95 ($943.18 in 2021) assembled
and tested. A comparable benchtop frequency counter today is the RISEPRO Benchtop
Frequency Counter for 10 Hz-2.4 GHz, at a cost just south of $90...
 Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, is pleased to introduce two new
90° power couplers, models IPP-7112 and IPP-7114. These surface mount couplers
are conservatively rated at 50 watts CW, and operate from 8.0-12.0 GHz and
6.0-12.0 GHz, respectively. The IPP-7112 and IPP-7114 product pages list the
complete product specs, and provide links to pdf files of the detailed Outline Drawings
and the Typical Test Data results for several parameters. In addition, these product
pages also offer links to the Simulated S-Parameters in s4p format, and the PCB
Mounting Footprint in dxf format. To view Technical Data Sheets in PDF format for
these products...
 A vertical antenna can have a significant
advantage over a horizontal antenna from a maintenance perspective, since, depending
on how high the antenna is mounted off the ground, the "business end" where electrical
connections are made are more accessible. The configuration shown here would be
difficult to implement if a mast rotator is to be used because of the stabilizing
guy wires on the lower frame. Although it should be possible to achieve the necessary
rigidity without guys by using an aluminum or fiberglass tubing frame rather than
wood, preventing weathervaning in strong winds could prove difficult. A nifty feature
of this "reversible
beam" antenna that appeared in a 1940 issue of QST magazine is that
reciprocal directivity is implemented simply by swapping out a short length of wire
between the director and reflector elements...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
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