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4 of the July 2021 homepage archives. Wednesday the 14th
 If you like the
radio-themed comics from vintage electronics magazines, then you'll appreciate
the jackpot of them (5) in the July 1945 issue of Radio Craft magazine.
Being the era in which it was published, many of the comics at the time had military-electronics
themes as well. A lot of them are credited to subscribers providing ideas. One of
my favorite features is "Radio Terms Illustrated," where readers write in with suggestions
for how common lingo in the radio realm can have an alternate interpretation. Such
is the case with "Wave Trap" in the first comic. I think Frank Beaven was the illustrator
for all of them. Look in the big list of other technical-themed comics at the bottom
of the page for others which include "Radio Terms Illustrated."
 Making novelty items from electronics parts
is nothing new. Lots of photos can be found on the WWW where very creative people
have fashioned some pretty incredible electronics art items from resistors, capacitors,
inductors, LEDs, PCBs, transistors, etc. Horseplay in the electronics realm also
enjoys a long heritage, as illustrated in this 1937 issue of Radio-Craft
magazine. I fondly recall the old days as a technician at Westinghouse Electric
when, on the evening shift, we used to get away with playing practical jokes on
each other in the lab. 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...
 The probability-based
quantum mechanical model of atoms has been in existence since around 1932 when
Robert Mulliken coined the term "electron orbital." It superseded the Bohr model
that modeled the atom as a proton/neutron nucleus that was surrounded by electrons
orbiting like planets around a star. For many decades thereafter, text books - particularly
those used in beginner level courses - continued to present the Bohr model and only
gave passing reference, if at all, to the quantum model. The Bohr model was and
still is easier for most people to envision, although as time goes on the percentage
of people who even recognize a planetary model is probably rapidly decreasing. This
article from a 1944 edition of Radio-Craft magazine chooses to use the Bohr model
as part of an introduction to electronics. Today, you might need to start from a
lower point and talk about groupies swarming around rock stars for most people...
 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.
 This vintage
Heathkit
AR-1250 Stereo Receiver kit is one the latest Heathkit kits which appeared on
eBay, although this one is mostly built. At least you can see the innards in the
photos. There appears to be a lot of parts to assemble, but by 1985 Heathkit was
shipping kits with major RF circuit components already mounted and tuned. Without
photos of the unassembled kit I cannot be sure, but being declared "a four-evening
kit" means it likely did have pre-assembled sections. I have been saving these kinds
of images in order to preserve the history. A constantly growing list is at the
lower right. The first instance of the AR-1250 Stereo Receiver I could find in a
Heathkit catalog is in the 1985 Spring-Summer issue with a price of $349.95, but
by the time the 1985 Christmas issue was mailed, the price had been lowered to $299.95
($745.61 in 2021 money per the BLS Inflation Calculator)...
 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 ...
 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.
Tuesday the 13th
 Glenn Bradford's delve into "Electronics
- at Work" is deep and wide. In this June 1945 issue of Radio News magazine,
he hits on many of the main issues being debated in the mid-1940s regarding what
role electronics would and should play in regrouping society following World War II.
Major advances in mechanics and electronics were made during the war, and a huge
potential workforce for dealing with designing, manufacturing, selling, and servicing
of a vast array of promised appliances and gizmos was "out there" looking for an
opportunity. In spite of that, indecision and reluctance to take risks plagued industries
scurrying to adapt from a (sometimes forced) wartime production mindset back to
a consumer-centric mode. Whereas the government funded conversion to defense products,
it was up to companies to make the transition back. This is a very interesting insight
into the situation. Be prepared for an introduction to many new terms...
 Teledyne Relays today announced availability
of four new reed relay product families, all offering extremely long life of up
to 1 billion cycles, ideal for applications where high reliability is essential.
The new product lines complement the already broad array of rugged switching solutions
the company has been supplying for more than 60 years.
Reed relays offer a compact and lightweight solution for switching of AC or
DC signals. Contacts are hermetically sealed inside a glass envelope which protects
them from corrosion. Compared with other mechanical-based relays, reed relays offer
low power consumption, low contact capacitance and faster switching speeds...
 "Hong Kong University of Science and Technology
in China claims the first demonstration of room-temperature continuous-wave lasing
of quantum dash (QDash)
microdisk lasers (MDLs) on silicon in the C (1530-1565nm) and L (1565-1625nm)
optical communication bands. The devices were optically pumped, but the researchers
believe that electrically pumped MDLs could be realized in the future. QDash light
emitters are attractive since they are less affected by crystal defects arising
from lattice mismatches between silicon and III-V materials. Also, they are less
affected by thermal variations. The team envisages the realization of multi-channel
communication through the fabrication of different diameter and thickness disks
on the same substrate with reduced light-source volume and complexity..."
 Even in the age of computers and smartphone
applets for everything, some people still are not comfortable with mathematics,
including something as relatively simple as Ohm's Law. There are still a lot of
electronics tinkerers around who grew up in the pencil and paper era (like moi),
where slide rules ruled the day. While a software program or electronics calculator
is convenient for many uses, sometimes a printed graphical tool is easier to work
with - at least in a lab environment. Accordingly, for those who still appreciate
a good
resistor selection nomograph, here is one from the April 1967 edition of
Electronics World magazine. Here's a challenge for recent college grads that
are scoffing at the old guys who are right now having a grandkid print out a copy
of this nomograph for them: What is the resistor color code number...
 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...
 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.
Monday the 12th
 You might not know it, but
International Business Machines (IBM) gained its prominence in the computer
realm thanks to a massive contract awarded to it by the U.S. Department of War during
World War II for the Automatic Sequence Controlled Calculator (ASCC), an electromechanical
computer (also called Mark I). It was used for making calculations during development
of the atomic bomb by the Manhattan Project. IBM's success was rewarded with many
later contracts for fully electronic computers used in military equipment, by the
space program, and by university research departments (funded by the government).
The company grew quite large and had a very extensive technical workforce including
engineers, mathematicians, scientists, and technicians. While living in Burlington,
Vermont, in the 1980s, I got to know many IBM employees (IBM used to have a major
presence there). All were very pleased with the pay, benefits, and treatment by
the company...
 "Individual neurons in the human brain can
efficiently perform so-called Boolean operations; a type of algebraic operations
that include union, subtraction and intersection. Computing systems that emulate
biological neurons, such as neuromorphic computing systems, however, typically require
several devices to complete these operations. Researchers at Fudan University and
the Chinese Academy of Sciences recently developed
neuristors based on two-dimensional (2D) materials that can perform logic operations
individually, without the need for multiple devices. These neuristors, presented
in a paper published in Nature Electronics, could enable the development of better
performing bioinspired computing systems..."
 Back in the 1960s, Robert Balin created many
quizzes on various electronics topics for Popular Electronics magazine.
I have posted many of them (see complete list below). This one from the May 1962
issue is on the subject of
units of measure commonly found in electronics work. All are still found in
modern devices, so you don't need to be an expert on vacuum tubes and selenium rectifiers
to get a good score. I missed the one for the tape deck, but then I don't ever remember
concerning myself with the electrical and magnetic characteristics of tape decks.
Maybe you will do better.
 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!
 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.
Sunday the 11th
 This
Microwave Engineering Theme Crossword Puzzle for July 11th 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!
 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.
Friday the 9th
 "The more things change, the more they stay
the same," applies to many things, and certainly does for crowding issues in the
electromagnetic spectrum. Just as with a gas in an expanding volume, uses for newly
opened regions of the radio spectrum are quickly occupied by new users. From the
beginning of the radio age, the ability to utilize higher and higher frequencies
was limited only by available technology - first vacuum tubes and now semiconductors.
Now, as then, it is the higher power transmitting side of the communications equation
that governs the upper frequencies. Designing components which work both at high
frequencies and high powers is much more difficult than designing for lower powers.
Capacitance, inductance, electron travel times, and voltage breakdown barriers are
the culprits. This 1945 article from Radio News magazine discusses some
of the issues which needed to be overcome in order to
expand
television broadcasting comfortably into the UHF region. Many industry forces
were behind the push in order to open new markets and to squeeze more revenue-producing
programming into existing spaces. Somewhat unexpectedly, the advent of cable television
(CATV) thwarted well-laid plans for over-the-air broadcasting, and as history shows...
 Infographics
were very popular about a decade ago, and were actually useful and informative in
most cases. Electrical engineer Mr. Mogale Modisane, CEO of ToolsGaloreHQ.com, wrote
to let me know about an infographic he created entitled "Multimeters:
An Incredible History in Pictures (1830 until today)" which traces the evolution
of multimeters. It begins with the basic galvanometer and progresses with the avometer
(for amp-volt-ohm, a term I don't recall knowing), then on to digital multimeters.
The webpage also has a section on the various patents that shaped the industry and
discussions on related technical topics. Mogale notes, "In 1980 the Fluke Corporation
(one of the largest multimeter manufacturers in the world even today), developed
the first practical multimeter that could fit in one's hand." Seeing the 8020A meter
really makes me feel old because I can remember using one when it was relatively
new. Some of the other articles are pretty good, too, like the
drill bit sharpening tutorial (or you can just buy a
Drill Doctor like I have). Take a quick look
if you appreciate historical aspects of our field.
 "Throwing
the works to my bottle." Any idea what that means? Neither did I, and no source
could be found for it. I assume it means cranking out max legal PEP in your power
amplifier vacuum tube. "You went out just like a Swedish match in a Kansas hurricane..."
Ever heard that saying? Neither had I. Evidently Swedish matches had a reputation
for easily going out. I never knew the Swedes made such fantastic matches. Clearly,
the tech jargon in 1935 was a bit different than today. This story from a 1935 issue
of QST magazine will introduce you to many new terms with a fairly short
read. The guy in the story looks a lot like the Ham in the 2013 Field Day patch...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
 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.
Thursday the 8th
 EME (earth-moon-earth)
amateur radio enthusiasts will be interested in reading this report of the first
known instance of bouncing a radio signal off the surface of the moon and then receiving
it. The event was reported in the April 1946 issue of Radio Craft magazine. A highly
modified "SCR-271" radar set was used, and operated at the standard frequency of
111.6 MHz. Aside from customizing the pulse width and repetition rate, an adjustment
to the receiver was necessary to account for the Doppler shift of the return frequency
due the the moon's motion relative to the earth. Handling Doppler frequency shifts
was necessary in the course of normal operation, but the moon, depending on its
position in the sky, could be moving as fast as 750 miles per hour - faster than
any airplanes of the era. Also presented this month was the first commercially operating
RF food heater...
 Antenova Ltd, UK-based manufacturer of antennas
and RF antenna modules for M2M and the IoT, is announcing a compact high performing
antenna for the 5G bands worldwide, including LTE band 74 1420-1520 MHz and
617-698 MHz.
Lutosa is a flexible antenna measuring 95 x 15 x 0.15 mm, making it ideal
for smaller designs, as it can be curved or folded and inserted into the device
The antenna is linear polarised and showed high efficiency in tests. Antenova has
designed Lutosa for easy integration into a device, the antenna does not require
a ground plane or a matching network, and is simply fixed in place using its own
self-adhesive strip...
 The mere sight of a
Nixie tube evokes passion and nostalgia in the hearts and minds of vintage electronics
aficionados. For the uninitiated, Nixie tubes were one of the most successful early
numeric display formats. They had wire filaments shaped in the form of numerals
0 through 9, stacked front-to-back inside a vacuum tube enclosure. Rather than the
filament (wire) doing the glowing, the neon gas (plus traces of others) fluoresces
(glows) in the vicinity of the wire. 7-segment LED displays had not yet hit the
commercial market when this story was published in a 1970 issue of Popular Electronics
magazine, so even though the numeric display uses vacuum tubes (Nixie) the power
supply, counter, and display driver circuits use semiconductors rather than vacuum
tubes. Very extensive circuit descriptions, building instructions, schematics, and
photos are provided...
 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...
 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.
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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