 Wednesday the 14th
 Here in this 1954 issue of Radio &
Television News magazine is one man's (Commander Paul G. Watson, USNR (ret.)
collection of early vacuum tubes and a bit about them. It reaches back to Dr. Lee
de Forest's farther than even earliest Audion tubes - including the "UltraAudion"
- to include the flame-based detector and amplifiers he worked on. For a very thorough
history of de Forest's work from the vantage point of both the good Dr. and
those who worked with him, including a story by William Howard McCandless (the man
who's glass blowing business built the various tubes for de Forest), check out
the January 1947 issue of Radio-Craft magazine. It celebrated the 40th
anniversary of the de Forest Audio tube. I wonder where this collection of
tubes is today. Many priceless collections of technical history artifacts end up
being mistakenly or ignorantly disposed of...
 "Total
semiconductor
unit shipments, which include integrated circuits as well as optoelectronics,
sensor/actuator, and discrete (O-S-D) devices, are forecast to rise 13% in 2021,
to 1,135.3B (1.1353T) units to set a new all-time annual record, according to IC
Insights' McClean Report - A Complete Analysis and Forecast of the Integrated Circuit
Industry. It would mark the third time that semiconductor units have surpassed one
trillion units in a calendar year - the first time being in 2018. The 13% increase
to 1,135.3B semiconductor units follows a 3% increase in 2020..."
 This quiz is based on the information presented
in Conquer
Radio Frequency, by Francesco Fornetti. See my review for the online version.
This material, which includes a full-color textbook and over 12 hours of video tutorials
(in mp4 format on enclosed DVD-R), provides a comprehensive guide for the RF and
Microwave engineering student or junior professional. It allows the reader to achieve
a good understanding of the foundation theory and concepts behind high frequency
circuits as well illustrating the most common design and simulation techniques for
passive and active RF circuits. A preview of the textbook, a comprehensive description
of the content of the video tutorials and sample video tutorials are available on
the Explore RF website.
 Edel Cashman has a good article on the Electronic
Design website entitled, "The
Engineering Essentials Behind LiDAR." LiDAR works by the same principles as
sonar and radar, but rather than sound and radio frequencies, it uses light. Its
extremely short wavelengths makes it ideal for high precision positioning and navigation
- such as with autonomous vehicles. Mr. Cashman (great name, BTW!) begins,
"LiDAR (light detection and ranging)... applies the principles of reflected light
and accurate timing to measure the distance of an object. LiDAR permits superior
depth sensing due to its high levels of depth and angular resolution. In addition,
it's able to operate in all light conditions due to the active approach that uses
an infrared light transmitter along with a receiver. However, LiDAR is more sophisticated
than just a distance measure. It can also be used in 3D mapping and imaging, making
it very appealing in an engineering context as well as a very useful practical technology.
There are different approaches to LiDAR..."
 At least for now, I am going to only scan
and post Radio Service Data Sheets like this one featuring the
Belmont 4-Tube Model 408 (Series A) Battery "Farm" Superhet radio in graphical
format, rather than run OCR on them to separate the textual content. It appeared
in the October 1938 issue of Radio-Craft magazine. There are still many
people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information. No example of this radio
could be found on the WWW...
 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
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Tuesday the 13th
 Before seeing this announcement for the impending
premier issue of
Popular Electronics magazine, I though the October 1954 issue was the first
to be published. According to this August 1954 Radio & Television News
magazine feature, Popular Electronics was to debut in September 1954, not
October. The teaser cover photo showed a family at a picnic table with more radio
equipment than food - including a big spring-loaded 1/4-wave whip antenna mounted
to the trunk of their car. It was never used for any issue from what I can find,
nor did the article entitled, "WABD's Empire State Building Television Transmitter."
A bit of research shows that the planned September 1954 issue never was. In fact,
editor Oliver Read's first column, entitled, "Meet Popular Electronics," confirmed
my finding. He wrote in part, "POPULAR ELECTRONICS is the answer to the demand for
a monthly publication devoted entirely to electronics..."
 "Frank Howell, K4FMH, followed up his two-part
National Contest Journal (NCJ) series, 'The
Demographics of Contesting,' with a post to his Social Circuits blog, called
'Lemmings over a Demographic Cliff?' Howell points to data showing that radio contesters
are older than the average ARRL member. Taking into account information from the
Bureau of Labor and Statistics on Leisure Time Use, Howell opines that this should
be expected. 'Leisure pursuits are highest during youth and young adulthood but
dramatically taper off about ages 25 - 34 until age 55 and over,' Howell said. 'This
hollowing out of leisure and sport time is a predictable outcome of competing and
more important activities.” According to Howell, the main competitor to radio amateurs
engaging in on-the-air or workshop activities is television. No surprise there..."
  This vintage
Heathkit
GR−48 AM/FM Table Radio kit just showed up on eBay, and will be on auction until
Monday, April 19th, 2021 (in case you would like to bid). The listing states it
is of 1969 vintage, but the GR−36 shows up in the 1969 Heathkit catalog; the GR−48
first appears in 1970. Photos of the kit are from the current GR−48 listing noted
above, and photos of the fully built kit are from an expired GR−48 listing. In the
interest of preserving the memory of Heathkit's great legacy in the electronics
realm, I have been looking for examples of unbuilt kits on eBay and posting some
of the photos here on RF Cafe. Heathkit products were well known for the completeness
of its instruction manuals, with clearly illustrated instructions. During the writing
and editing process, Heathkit employees were given pre-production kits to take home
and build, while annotating any difficulties or errors encountered. Doing so helped
minimize the situation where the writer inadvertently assumes his own familiarity
with the process is shared by the customer...
 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!
 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 USA.
Monday the 12th
 Here is another of the "Radio
Term Illustrated" type of comic, which appeared in the December 1939 issue of
Radio News magazine. The DXing Hams can get a bit animated when trying
to squeeze the last picowatt out of a long distance contact. I'm not sure why the
guy is depicted as a country hick when for certain there were plenty of polished
city slickers who resorted to the same antics. A big list of other electronics-themed
comics is at the bottom of the page, many of which contain other of the "Radio Term
Illustrated" style.
 "China and the U.S. continue to top the 5G
charts, with VIAVI's The State of 5G Deployments report showing that the countries
have 341 and 279 5G-connected cities, respectively. In China, the number of cities
with 5G grew six-fold in one year, while coverage in the U.S. increased by a factor
of five. Further, in Ericsson's November Mobility Report, 220 million 5G subscriptions
were expected by the end of 2020, an estimation that the company increased as a
result of China's faster-than-expected uptake, which was 'driven by a national strategic
focus, intense competition between service providers and more affordable 5G smartphones
from several vendors.' Chinese telecom carriers are expected to build over 1 million
new 5G base stations in 2021..."
 James A. Crawford, proprietor of AM1
LLC, has written and published a large collection of
electronics-related technical papers available
for download. Topics include antennas, communication systems, design reviews, digital
signal processing, frequency synthesizers, modems, orthogonal frequency division
multiplex (OFDM), oscillators, phase-locked loops, phase noise, technical proposal
writing, radio design, RF design, software defined radio (SDR), tunable filters,
WLAN, and much more. He is also the author of a book entitled, "Advanced Phase-Lock Techniques."
You might enjoy his "Dreaded
Interview Questions for Fun" paper to see how well you do answering the questions.
BTW, I didn't get the job ;-(
 David Vye has an article on the High
Frequency Electronics website entitled, "Multiband
Active Antenna Tuner for Cellular IoT Applications," that introduces the concept
of a device that can maintain a reasonable impedance match between the transceiver
and antenna over a wide bandwidth. This is different than an active antenna steering
device. Because wireless products (smartphones, tablets, etc.) a nowadays required
to accommodate many frequency bands over a large range of spectrum, traditional
methods of switched Tx/Rx paths according to the selected band of operation are
getting bulky and expensive since they include a number of discrete components.
Mr. Vye begins, "With the release of each new generation of wireless technology
since the introduction of the portable phone in the early 1980s, mobile communications
have progressed exponentially. Each generation has launched new services and business
opportunities, leading up to what is being referred to as the 'third wave' of communications..."
 When the caption for a photograph in a 1931
article refers to an "antiquated" motor, you can be sure you're looking at a really
old motor. Indeed it does look very old. Whenever I see vintage photos or films
of electrical / electronic apparati [sic] and operators, I always
look for
safety issues like no eye protection while soldering or when using powered tools
to fabricate enclosures, lack of protective shields around electrical connections
and mechanical drive mechanisms, wearing of inappropriate clothing near rotating
machinery, etc. In this case you can see a very long, totally exposed drive belt
running between that aforementioned antiquated motor and DC generator that it drives
(to power the transmitter). The author mentions how the floor shook while it was
running...
 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...
 TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Sunday the 11th
 This
Microwave Engineering Crossword Puzzle for April 11th has many words and clues
related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry,
physics, and other technical subjects. 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.,
Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists
amongst us will appreciate the effort. Enjoy!
Friday the 9th
 In his April 1946 Radio-Craft editorial
column, Hugo Gernsback reflected on the great advances made during the past half-decade's
war efforts, and predicts that the
field of radio-electronics will see explosive growth. Of course it didn't require
Mr. Gernsback's usual extraordinary visionary skills to make such a claim at
that time. Cyclotrons, Betatrons, VHF, UHF, and microwave amplifiers and vacuum
tubes, cathode-ray tubes, transmission lines, waveguide, and countless other technologies
had recently been developed anew or improved from pre-war designs. Engineers and
technicians were to benefit greatly from the advances, as would, eventually, consumers
who would be buying the wonderful new products made from those newfangled devices.
Coming soon - likely much to his surprise...
 "The Pentagon has announced that one of its
offices has completed planned research and development work on a number of
unmanned drone swarming technologies and has now turned them over to the U.S.
Air Force, Army, Navy, and Marine Corps to support various follow-on programs. The
systems in question are the Block 3 version of Raytheon's Coyote unmanned aircraft
and an associated launcher, a jam-resistant datalink, and a software package to
enable the aforementioned drones to operate as an autonomous swarm. These developments
give us a glimpse into what has been a fairly opaque, integrated development effort
to field lower-end swarming drones across the services that leverages common components.
All of these technologies were developed under the auspices of the LCCM effort,
led by the Pentagon's JCTD program office..."
 All RF Cafe Quizzes make great fodder for
employment interviews for technicians or engineers - particularly those who are
fresh out of school or are relatively new to the work world. Come to think of it,
they would make equally excellent study material for the same persons who are going
to be interviewed for a job. This particular quiz challenges your knowledge of
Wireless Communications Fundamentals,
including questions on standards, terminology, and components. Bonne chance, Viel
Glück, がんばろう, buena suerte, удачи, in bocca al lupo, 행운을 빕니다, ádh mór, בהצלחה, lykke
til, 祝你好運. Well, you know what I mean: Good luck!
 When up in a small airplane or helicopter,
I have never had any sense of fear of heights, but when at the top edge of a really
tall building or at the precipice of a high cliff, the need to control the panic
sensation is required. It is not strong enough to prevent me from going there, but
I'm definitely not one of those fearless types that will go anywhere with reckless
abandon. Even seeing a photo like this one on the IEEE Spectrum website invokes
the fight or flight emotion. You need to click on the thumbnail to see the larger
version to really get a sense of the height at which the technicians are working.
The story is about China's
Changji-Guquan ultrahigh-voltage direct-current transmission link along the
Yangtze River, in Anhui province. Arguments abound over whether DC or AC is better
overall for electrical distribution, but the main reason for this DC line is to
accommodate energy storage at locations throughout the country...
 Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
Thursday the 8th
 This seventh installment in an eleven-part
series on "Theory
and Application of U.H.F." appeared in the October 1944 issue of Radio News
magazine. Author Milton Kiver covered a wide range of topics including basic and
advanced circuits, tube types, modulation, resonant cavities, oscillators, transmission
lines, waveguides, antennas, electromagnetic fields, and Maxwell's equations. Part 7
continued the discussion of how waveguides, both rectangular and circular, support
the conduction of electromagnetic waves. Methods for injecting and extracting signals
is covered as well. Interestingly, the Smith chart never appeared even though Phillip H.
Smith had introduced it around 1936. In fact, the first mention of the Smith Chart
in Radio News, per a WWW search, was in 1950...
 "Telecom operators around the world are deploying
5G using higher frequencies in both the sub-6GHz band and mm-wave
bands. This has pushed OEMs to look for new antenna technology platforms with larger
bandwidths, higher efficiency, and better thermal management. GaN technology has
become a serious competitor to LDMOS and GaAs in RF power applications, showing
continuous performance and reliability improvement leading, potentially, to a lower
cost at the system level. Yole expects the total GaN RF device market to go beyond
US$2 billion in sales by 2025 with a 12% CAGR between 2019 and 2025. In the dynamic
5G infrastructure market, there is a continuous race for more efficient antenna
types. Switching technology from Remote Radio Head (RRH) to Active Antenna System
(AAS) will transform the RF front ends..."
 Who doesn't
like a good practical joke - especially if it's played on someone else while you
watch? This "Testers,
Beware of this April 1st Prankster" story appears on the Electronics Design
website. It trumps the one I fondly recall from my days as a technician at Westinghouse
Electric in the 1980s. On the evening shift, we used to get away with playing practical
jokes on each other in the lab; new hires were sure to get the treatment. Ours were
low tech stuff like connecting a high voltage supply to someone's metal toolbox
or squeezing water from a soldering iron sponge wetting bottle through a length
of plastic tubing (taped under a workbench) onto a guy's crotch while he was working
intently on something. You'd probably get fired or sued for such shenanigans in
the workplace today.
 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...
 Allen-Bradley has been making resistors for
a long time, as evidenced by this advertisement from the December 1931 edition of
the ARRL's QST magazine. From my earliest days in electronics in the 1970s, I remember
using their products in hobby projects and then later in professional applications.
Rockwell Automation now owns Allen-Bradley, so if you want historical information,
you will have to do a search for pages like this one. According to Wikipedia: "The
company was initially founded as the Compression Rheostat Company by Dr. Stanton
Allen and Lynde Bradley with an initial investment of $1,000 in 1903. In 1910 the
company was renamed the Allen-Bradley Company."
 ConductRF, a manufacturer of precision RF
coaxial cable assemblies and connectors, announces the availability of
Phase Stable / Temperature Stable solutions for both commercial
and laboratory precision RF applications. 50 ppm phase accuracy with temperature
phase matching capabilities, low loss and high power options, broad connector choices.
Manufacturing capabilities include solutions built at our ITAR registered facility
in Methuen, Massachusetts, as well as partner facilities in the U.S. and around
the world. ConductRF offers cost effective equivalent and improved RF solutions
to all major interconnect manufacturers, specializing in phase stability over temperature...
 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.
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