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4 of the August 2021 homepage archives. Friday the 6th
 What better way to wind down a week than
to get a chuckle out of some
electronics-themed comics from vintage magazines?!?! These three came from WWII-era
editions of Radio News. The humor of the depicted scenarios might be lost on people
who were not in the workforce back in 1970s and earlier when workplace and supply
chain conditions were much different than they are today. Therefore - not to be
insulting - I'll give a little insight. Back in the days before online ordering
of just about anything the entire world has to offer, service shops and even design
centers relied heavily on sales representatives to procure parts. That is the gist
of the p53 comic. The p56 comic alludes to when something as harmless as listening
to a radio at your workbench was not permitted. Nowadays, of course, you can sit
at your workstation with a Bluetooth ear bud and privately listen to anything you
want being broadcast from the smartphone in your pocket...
 "The US Department of Defense's Missile Defense
Agency is using a pair of CubeSats to develop a system to track hostile ballistic
and hypersonic missiles from launch to impact. Part of the Nanosat Testbed Initiative,
the CubeSat Networked Communications Experiment (CNCE) Block 1 was launched from
the Mojave Air and Space Port in California on June 30 for a three-month technology
demonstration mission. As
hypersonic missiles rapidly move toward becoming practical weapons, the problem
of how to counter them is also on the agenda. One American response being developed
by the MDA is the Hypersonic and Ballistic Tracking Space Sensor (HBTSS), which
is being developed in competition between Northrop Grumman, Raytheon, Leidos, and
L3Harris. When deployed aboard satellites in low-earth orbit, the HBTSS aims to
globally track hypersonic missiles in all phases of their flight..."
 Mr. Kenneth Wyatt, always dependable
for a useful short article on RF subjects, has a piece on the EDN website
entitled, "EMC
Antennas for Troubleshooting and Pre-compliance Testing." He begins: "EMC antennas
are an important component for capturing radiated harmonic emissions from products
being tested. There are two considerations: simple troubleshooting or calibrated
pre-compliance testing. For troubleshooting purposes, most any uncalibrated antenna
may be used. I’ve even had clients use Wi-Fi antennas for detecting emissions in
the 50 to 200 MHz range. Basically, if your antenna can sense the emissions, it
can be used for general troubleshooting. Pre-compliance testing, on the other hand,
is where you’re trying to duplicate the emissions testing as performed by an EMC
test lab and that will require a more expensive calibrated antenna..."
 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 "A Smorgasbord
of RF Topics" quiz touches on a wide range of subjects ranging from Bluetooth
to WLAN and ESD testing standards.
 Here is an advertisement by Corning from
the May 29, 1948, edition of The Saturday Evening Post. The Hale 200-inch
telescope mirror was dedicated for service at
Mount Palomar on June 3, 1948, at the in honor of George Ellery Hale. As a side
note, it is interesting that in the magazine of the era (which were typically quite
large in width and height), actual photographs like this one were rarely used in
advertisements. The vast majority of artwork was... artwork - pencil drawings or
actual paintings. Tomorrow a new door to the secrets of the universe will be gin
to open. A door through which astronomers will be able to see 6,000,000,000,000,000,000,000
miles into space...
 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...
 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.
Thursday the 5th
 Here is yet another report on the wonders
of
radar technology as the country was coming out of the throes of war. As mentioned
before, radar was a highly classified science during World War II, and it is
credited, along with the Douglas C-47 and the Jeep (two of General Eisenhower's
four "Tools of Victory") for being a major contributor to Allied success. At the
beginning of war, when radar operators in Hawaii were misinterpreting squadrons
of attacking Japanese aircraft for a flight of B-17 bombers being ferried from the
mainland, radar displays were essentially x-y axis oscilloscopes indicating range
and signal strength. By the end of the war, the antenna-synchronized rotating plan
position indicator (PPI) format had been introduced, providing a much more useful
format for determining target situations. Radar was adapted...
 "Digital transistors - assembled by the billions
in today's computer chips - act as near-perfect electronic switches. In the "on"
position, achieved when an above-threshold voltage is applied to the device, the
transistor allows current to flow. When the switch is off, the transistor prevents
the flow of current. The on/off positions of the switch translate into the 1s and
0s of digital computation. Although these 1s and 0s are fundamental to the operation
of a computer, complex computations require that the data be
stored in memory in order to be useful. In today's chips, memory relies on another
device, in addition to the transistor: a capacitor that stores electric charge.
The capacitor is empty when the transistor is switched off and flooded with electric
charge when the transistor switches on. The charge on the capacitor then preserves
the 1 or 0 of the transistor's switch state..."
 A large portion of the U.S. has experienced
prolonged periods this winter with temperatures substantially below long-term averages.
That means heating systems have been running much more often than usual, and if
you have a forced hot air system, that means the indoor humidity level has been
much lower than normal. In northern areas like where I live, humidity can easily
drop to near zero. Because of that, triboelectric charging to high voltage potential
occurs merely by walking a few steps across a carpet, resulting in a sometimes painful
discharge arc when a metal object is touched. The only way to mitigate low humidity
conditions is to add water back into the air. The preferred option, IMHO, is to
install a whole-house humidifier that resides on the furnace ductwork, has its own
regulated water supply, and is controlled by a humidistat. After a couple weeks
of refilling three free-standing humidifiers two to three times a day and listening
to the fans, I decided it would be worth the expense and effort to install a whole-house
humidifier. The
Honeywell HE240A whole-house humidifier with a couple additional parts...
 ASC designs and manufactures hybrid, surface
mount flange, open carrier and connectorized amplifiers for low, medium and high
power applications using gallium nitride (GaN), gallium arsenide (GaAs) and silicon
(Si) transistor technologies. ASC's thick film designs operate in the frequency
range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up
to 20 GHz.
 This design for a "Swiss Quad"
antenna appeared in the September 1967 edition of QST magazine. One of
its touted strong points is not needing spreaders or a boom. I am not an antenna
design guy, so I can't comment on its usefulness. No gain measurement was provided
by the author. The article states that the antenna had not yet enjoyed widespread
adaptation in the U.S. at the time of the writing. A Google search for Swiss Quad
antennas turns up a handful of modern examples: IW5EDI, VK4JU, LU7MGP. I could not
locate an example of a computer-generated gain plot (radiation pattern) for the
Swiss Quad, so if you know where one exists, please let me know so I can post a
hyperlink...
 For a long time, the Electronic Warfare and
Radar Systems Engineering Handbook was very difficult to locate unless you knew
right where to go. Over time, some websites had been posting the file on their own
servers, but it is a pretty big PFD file, and it really has not been very well indexed
by Google or Yahoo or the other search engines. Therefore, I have broken it into
smaller parts and posted it in HTML format. That will make viewing specific chapters
much faster and easier. This chapter on
Doppler
Shift is typical of the manner in which subjects related to EW and radar engineering
are put in layman's terms...
 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...
 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.
Wednesday the 4th
 Before comprehensive coaxial and optical
cable or even microwave relay networks were available for commercial use, an experimental
aircraft-based system was tested for broadcasting educational television and other
messaging data. The "Stratovision"
platform essentially provided a couple 20,000-foot-high antennas with a footprint
covering hundreds of miles. This 1945 Radio-Craft magazine article entitled
,"Stratovision" was one of the earliest to report on plans to provide a coast-to-coast
nationwide matrix of coverage as shown in the accompanying illustration. Two outfitted
airplanes would be in the air within each region at all times to ensure redundancy
and high quality service. Boeing B-29 Superfortress airplanes (the Enola Gay was
a B-29) were used at least in part because they provided a human-friendly environment
at high altitudes for long period of time...
 "Another
step towards
space exploration from UK soil has been unlocked, with the passing of the spaceflight
regulations, Transport Secretary Grant Shapps announced 29 July 2021. The legislation
provides the framework to regulate the UK space industry and enable launches to
take place from British soil for the very first time. It will unlock a potential
4 billion pounds of market opportunities over the next decade, creating thousands
of jobs and benefiting communities right across the UK. This also puts the UK in
a unique position as the first country in Europe able to launch spacecraft and satellites
from home soil..."
 Here are a few more
electronics conundrums with which to exercise the old noodle. These are puzzlers
from a 1959 issue of Popular Electronics magazine, but at least one of
them (#4) will likely prove to be a real stickler unless you have seen a similar
resistor mesh problem before (see my solution for the resistor cube equivalent resistance).
There are no tube circuits to use as an excuse for not attempting them - just resistors,
batteries, switches, meters, a motor, and a couple light bulbs. All four would be
fair game to present to an interviewee to see where he/she stands on basic circuit
analysis...
 I've long hoped to
per-household-sized nuclear power generators that would eliminate the need for
an electrical distribution system, thereby eliminating single-point system failures.
It looks like China is on its way with its new reactors powered by melt-down-proof
thorium salts. While not personal sized yet, it's a start. The U.S. Department of
Energy has begun a similar program called
Advanced
Small Modular Reactors (SMRs), but has not advanced much beyond the conceptual
phase. Toshiba published info on its
Micro Nuclear Reactor in the 2007 timeframe, but it has disappeared now.
Mechanix Illustrated, Popular Science, et al, magazines promised me in the
1970s that we'd have them by the year 2000, and at 63 years old in 2021 I'm still
waiting...
 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."
Tuesday the 3rd
 This August 1962 installment of "Mac's
Electronics Service" entitled "Openers, Anyone?" discussed remote garage door
openers that were getting popular in the day. As usual there is a valuable lesson
taught in the story, but what really stands out in this case is how the diodes in
the schematic have a "+" sign shown on the cathode. Surely it was a printer's mistake
since even though that was the era when great debates were taking place over whether
electrical current flowed from positive to negative or vice-versa, there was no
argument over whether the more negative voltage needed to be connected to the cathode
(vacuum tube or semiconductor) in order for current to flow. The header image accompanying
John Frye's "Mac's Service Shop" technodramas underwent half a dozen or so versions
throughout its multi-decade run. It is the first I recall seeing this particular
version. The title of the series also evolved over time to reflect the era...
 A more common configuration for
transistor amplifiers is the common-emitter configuration. Positive feedback
is a little more difficult with this configuration because the input and output
signals are 180º out of phase. Positive feedback can be accomplished by feeding
a portion of the output signal of the second stage back to the input of the first
stage. This arrangement is shown in figure 1-19. The figure shows that each stage
of amplification has a 180º phase shift. This means that the output signal of Q2
will be in phase with the input signal to Q1. a portion of the output signal of
Q2 is coupled back to the input of Q1 through the feedback network of C3 and R3.
R3 should have a large resistance to limit the amount of signal through the feedback
network...
 "Electrical engineers from the UCLA Samueli
School of Engineering have developed a more efficient way of
converting light
from one wavelength to another, opening the door for improvements in the performance
of imaging, sensing and communication systems. Mona Jarrahi, professor of electrical
and computer engineering at UCLA Samueli, led the Nature Communications-published
research. Finding an efficient way to convert wavelengths of light is crucial to
the improvement of many imaging and sensing technologies. For example, converting
incoming light into terahertz wavelengths enables imaging and sensing in optically
opaque environments. However, previous conversion frameworks were inefficient..."
 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.
 The full headline from the South China Morning
Post reads: "China's job scarcity sees
fresh grads shun private sector for stable civil service jobs, as 'government
is too big to fail.'" This is happening in the U.S. as well - especially for non-technical
jobs (like those sought by people with degrees ending in "Studies"). "Skyrocketing
living costs and mounting uncertainties have become unbearable for those who desire
security, peace of mind and reasonable working hours that the private sector may
not offer." Further, is states a growing shang'an mentality among the young, which
literally means "going onto the shore" describes a growing desire among take lower
paying but more secure jobs in the public sector. The expression is the opposite
of his parents' generation: xiahai, or "going down to the sea, referring to a movement
during China's period of reform and opening up that began in the late-1970s, when
droves of people quit their government positions to become entrepreneurs and explore
a "sea" of business opportunities...
 A
"V" Antenna is a bi-directional antenna used widely in military and commercial
communications. It consists of two conductors arranged to form a V. Each conductor
is fed with currents of opposite polarity. The "V" is formed at such an angle that
the main lobes reinforce along the line bisecting the "V" and make a very effective
directional antenna (see figure 4-35). Connecting the two-wire feed line to the
apex of the "V" and exciting the two sides of the "V" 180 degrees out of phase cause
the lobes to add along the line of the bisector and to cancel in other directions,
as shown in figure 4-36. The lobes are designated 1, 2, 3, and 4 on leg AA', and
5, 6, 7, and 8 on leg BB'. When the proper angle between AA' and BB' is chosen,
lobes 1 and 4 have the same direction and combine with lobes 7 and 6, respectively.
This combination of two major lobes from each leg results in the formation of two
stronger lobes, which lie along an imaginary line bisecting the enclosed angle...
 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!
 Alliance Test Equipment sells
used / refurbished
test equipment and offers short- and long-term rentals. They also offer repair,
maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP,
Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization
with ability to source hard to find equipment through our network of suppliers.
Alliance Test will purchase your excess test equipment in large or small lots. Blog
posts offer advice on application and use of a wide range of test equipment. Please
visit Allied Test Equipment today to see how they can help your project.
Monday the 2nd
 "Morale
Radio" sets were manufactured by many companies and provided to service men
for entertainment and hearing news from back home and around the world. Unsubstantiated
sources claim American companies were paid cost + 15% for each set. Other countries
made similar "Morale Radios" for their troops, or procured sets from elsewhere and
made necessary modifications to suit their format. Not a whole lot of information
can be found about them on the WWW, and finding a photo of one of the German Wehrmacht
radios with the Swastika and eagle on it is darned near impossible, other than the
one shown in this 1945 Radio-Craft magazine article. Part of the reason for the
scarcity is the German people's desire to destroy as much of the Nazi (National
Socialist German Workers' Party) history as possible both to put the horrible era
behind them...
 "We're living in battery-powered times. Incredible
amounts of capital are going into gigaplants that produce
millions of battery cells per day, and there are rivers of cash flowing to R&D
on advanced batteries. There are fortunes to be made and new megacorporations to
be built. Not only will batteries be needed for our phones, laptops, power tools,
cars, ships, and planes, but also to store energy from renewable sources. Batteries
are key to decarbonizing our economies. It would be great if batteries could improve
exponentially, à la Moore's Law. But it'll never happen. Gordon Moore himself told
us so in his seminal 1965 magazine article, in which he predicted that we would
be able to double the number of components in a digital integrated circuit every
year for the next 10 years. He also said that the same..."
 Website visitor Neil S. requested that I post
information about the many openings for RF and microwave engineers, technicians,
analysts, and managers at the company where he works RGNext (Range
Generation
Next). RGNext employees
serve on the forefront of our nation's access to space and defense of our nation.
RGNext offers their team of experienced, professional employees an environment that
challenges, stimulates and provides personally and professionally rewarding career
opportunities. RGNext is looking for qualified individuals for assignments in the
Marshall Islands, Ascension Island, California, Alabama, and Florida.
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
 Notice that the output (collector) of Q1
is connected directly to the input (base) of Q2. The network of R4, R5, and R6 is
a voltage divider used to provide the bias and operating voltages for Q1 and Q2.
The entire circuit provides two stages of amplification.
Direct coupling has several disadvantages, however. The major problem is the
power supply requirements for direct-coupled amplifiers. Each succeeding stage requires
a higher voltage. The load and voltage divider resistors use a large amount of power
and the biasing can become very complicated. In addition, it is difficult to match
the impedance from stage to stage with direct coupling. The direct-coupled amplifier
is not very efficient and the losses increase as the number of stages increase...
 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...
 RF Superstore launched in 2017, marking
the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and
microwave Industry. Pasternack fundamentally changed the way RF components were
sold. Partner Jason Wright manages day-to-day operations, while working closely
with Mr. Pasternack to develop RF Superstore into a world class RF and
microwave
component supplier. RF coaxial connectors & adapters, coaxial cable &
cable assemblies, surge protectors, attenuators. Items added daily. Free shipping
on orders over $25. We're leading the way again!
Sunday the 1st
 This
Physics & Science Theme crossword puzzle for August 1st, 2021, 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!
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
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.
About RF Cafe.
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