Tuesday the 14th
 When this self-promotion of progress made
on the
transistor invention by Bell Telephone Laboratories appeared in the June 1952
issue of Radio-Electronics magazine, a mere three and a half years had
passed since the announcement of the achievement by Drs. Bardeen, Brattain, and
Shockley. Interestingly, it refers to germanium as a metal rather than as a semiconductor.
In that interim, many problems had been solved in the effort to make robust, reproducible
devices that were affordable replacements for vacuum tubes. One of the primary differences
between the most recent transistors and the early models was the use of doped junctions
rather than point contacts. This made them more resistant to effects of vibration,
temperature changes, and contamination, and also produced higher yields in manufacturing.
Gaining the confidence of designers was imperative if the newfangled technology
was to gain (pun intended) ground as the preferred component for amplifier, oscillator,
mixer, and other type of circuits traditionally...
 Reactel, industry leaders in the design and
manufacture of RF and Microwave filters, diplexers, and sub-assemblies from DC to
67 GHz, recently produced a new video short on
Flat-Pack Combline and Interdigital Filters. Benefits of waveguide filters include
low insertion loss, center frequencies up to 35 GHz, broadband operation, extremely
small overall size, high unloaded "Q." Custom designs are available, along with
variations on duplexers, diplexers, multiplexers, switched filter banks, and other
configurations. Many off-the-shelf products are available, and Reactel engineers
are happy to assist you with determining your system's needs and designing filters
to help you succeed. Please take a couple minutes to view this video, and then give
Reactel a call...
 "Father of Radiovision" (RV) was the title
bestowed upon
Charles Francis Jenkins for his work in what would eventually become known
as television (TV), which is a very good thing because otherwise mass confusion
would have ensued by now due to the ambiguousness of having to contend with a familiar
reference to recreational vehicles (RV) when the "other" RV is what was meant ;-)
Mr. Jenkins was also the inventor of the Phantoscope motion picture machine.
BTW, did you know that the Coast Guard was originally called "Life-Saving Service?"
See other "Men Who Made Radio" : Sir Oliver Lodge, Reginald A. Fessenden, C. Francis
Jenkins, Count Georg von Arco, E. F. W. Alexanderson, Frank Conrad, Heinrich Hertz...
 RF Cafe visitor Jonathan Z. sent me
a link to the Bureau of Labor Statistics'
Occupational Employment
and Wage Statistics page where it reports on salaries of U.S. engineers in 2021.
According to them, there were 186,020 electrical engineers (not including self-employed
like moi), and the mean wage was $107,890 per year exclusive of bonuses, benefits,
stock options, and other incentives. Those in the median (50th percentile) made
$100,420. The lowest percentile (10%) pulled in $62,360 - which is about where I
am with RF Cafe, and that's with no insurance coverage, retirement, etc. It
is just over the point where Obamacare offers a subsidy, and the low-end plan (the
Bronze Plan - I call it the Rust Plan) costs >$20k/yr out of pocket (premium
cost + deductible for husband and wife over 60 years old), and then only pays 60%
of bills. But I digress... The top paying industries for EEs are data processing,
oil & gas, technical & trade schools and petroleum & coal extraction.
Note the absence of consumer product designers - they're mostly overseas. where
most of the stuff we buy is made. Don't worry. Be happy.
 Most of us, long before being introduced
to the concept of power in electrical circuits, learn about it in terms of mechanical
power and/or sound power. It takes some doing to abandon the esoteric nature of
power and be trained to grasp the scientific and mathematical aspects of power in
all its forms. When the driving source is steady state or a pure sinewave, life
is relatively simple, but such is more often than not an exception to the system
being studied. Here is a nice, short treatise in a 1960 issue of Electronics
World magazine on the concept of sound power that will augment your earlier-learned
knowledge of
music power rating...
 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...
 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.
Monday the 13th
 1934
was still riding the back of the high voltage craze popularized by Nikola Tesla
at the turn of the century. Super high voltage spark gap transmitters were still
being used in long distance communications for special applications. William Haight
was one of many people engaged in weather manipulation - both its creation and destruction.
Transportation, agriculture, and recreation would greatly benefit from the ability
to locally and temporarily control weather. This story of Mr. Haight's high-voltage
"electrodrome"
machine appeared in the May 1934 issue of Flying Aces magazine. Another
version of this electrodrome article by author Mel Wharton, entitled "Eliminating
the Peril of Fog," appeared in the April 1934 edition of Flying magazine.
There he says, "Repeated tests have shown that the operations of dispersing fog
is most effective at about 600,000 cycles - though work is done all the way on a
range from 500,000 to 1,500,000 cycles. The machine is capable of developing 500,000
volts, but only a fraction of this voltage is found necessary." A 4½ horsepower
gasoline engine-powered generator provides the voltage. A May 1935 issue of
Popular Mechanics magazine reports on Mr. Haight's electrodrome work...
 On the page immediately following an article
titled "TVI and the Novice," the National Company ran one of its conventional full-page
informational advertisements - on the subject of TVI. This one, appearing in the
October 1953 issue of QST magazine, is number 234, and it is the newest one I have
so there likely were many more. National's suggestion for curing TVI issues was
to use a shielded chassis with chokes in series and bypass capacitors in parallel
with power leads. A complete list of all my National Company advertisements is at
the bottom of the page...
 The ARRL website recently posted a notice
seeking an
Administrative Coordinator for the ARRL Foundation's Club Grant Program. Is
says: "The independent contractor will coordinate, administer, manage, and organize
club grant applications at ARRL Headquarters in Newington, Connecticut. The Club
Grant Program seeks to fund transformative projects that enable growth for amateur
radio operators, on the air projects, ham radio training and mentoring, and more.
The program is funded by Amateur Radio Digital Communications (ARDC), and it will
award a total of $500,000 in club grants throughout 2022. To apply for this contract
position, send a biography or profile to
hr@arrl.org.
Visit the ARRL website for a complete job
description."
 RF Cafe visitor Jim L. requested that I
post this Build Your Own Vibrato article from the December 1957 edition of Popular
Electronics magazine. "Make like Elvis with an 'electronic' throbbing guitar,"
is the pitch line. Vibrato, for the non-musically inclined, is the "wa-wa" sound
of an instrument as it smoothly wavers in pitch about a central note. This circuit
is for use with an electric guitar, but acoustical stringed instruments like the
violin and cello are routinely played with vibrato effect by rocking the finger
up and down the length of the string. In typical 1950s style, the project is built
with point-to-point wiring rather than using a printed circuit board...
 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 12th
 This custom made
Engineering Theme Crossword Puzzle for June 12th is provided compliments of
RF Cafe. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger,
and have only words and clues related to RF, microwave, and mm-wave engineering,
optics, mathematics, chemistry, physics, and other technical subjects. As always,
this crossword puzzle 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!
 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.
Friday the 10th
 Somehow, after being in the RF business
for four decades, I have to admit to not being familiar with the term "acceptance
angle" for antennas. That is after having read scores of articles on antennas. Maybe
I did and just don't remember - embarrassing. Acceptance angle is mentioned and
explained in this 1949 Radio & Television News magazine article during
the description of
rhombic antenna characteristics versus dipoles and multi-element designs. Although
the author focuses on television installations, information provided on signal reflections,
shadowing, ghosting, multipath, etc., is applicable to radio as well...
 "Every year, the
Bluetooth SIG member community works hard to deliver innovations that improve
the capabilities of Bluetooth® technology and help shape new market trends. From
wireless audio and wearable devices to asset tracking and network lighting control
solutions, Bluetooth SIG member companies continue to meet the needs of consumer,
commercial, and industrial use cases. Thanks to the hard work of everyone involved,
the LE Audio specification project is nearing completion. It is, perhaps, the most
complex specification project the Bluetooth SIG has ever taken on, involving hundreds
of people across multiple working groups and committees. We look forward to completing
the project this year and ushering in the next 20 years of audio innovation..."
 Innovative Power Products (visit us at
IMS 2022 Booth #4110),
a designer and manufacturer of RF and microwave passive components for more than
three decades, is pleased to introduce a new
2-way power combiner / divider covering the 2000 to 8000 MHz band, with
a power handling capacity of up to 150 watts. The model IPP-1300 combines two
coherent input signals or divides one signal into two up to 150 watts CW of total
RF power. This combiner/divider is produced in a 1.5" x 2.5" x 1.03" package with
a type N connector on the sum port and SMA connectors on the two other ports. This
coupler has insertion loss less than 0.55 dB, with phase balance that is less
than ±6°. The VSWR is less than 1.30:1, and the amplitude balance is less than ±0.25 dB.
The IPP-1300 is also RoHS compliant. Visit our website to download a Technical Data
Sheet, drawing PDF, and for Typical Test Data...
 For someone interested in getting into aviation
electronics in 1948, this career deal offered by
American Airlines was an exceptional opportunity. If chosen for the program,
an intense six-month training regimen would prepare the student for a career in
radio, radar, navigational aids, and other systems. All living costs would be covered,
along with a $120 per month stipend which, according to the Bureau of Labor Statistics'
Inflation Calculator, is the equivalent of about $1,450 ($17.4k/yr) in March of
2022. Although I don't have the numbers, my guess is that this was a much better
deal than the military was offering at the time, especially considering no conscription
was involved. American Airlines began service in 1936, and is one of the few carriers
of the era still in operation today...
 The
Bureau of Labor Statistics (BLS) just published their latest numbers on the
Consumer Price Index (CPI) for the 12-month period covering May 2021 to May
2022. You probably haven't noticed, but prices for everything has increased significantly.
The people responsible for it try to blame Putin due to the war in Ukraine, but
if you look at the statistics, the rise began in February 2021 (Ukraine began in
2022). Food is up 10.1% (meat up 14.2%), energy is up 34.6% (fuel oil up 106.7%,
electricity up 12.0%), new vehicles up 12.6% (used up 16.1%), airline fares up 37.8%.
At 64 years old, my expenses are getting out of hand (including medical with no
insurance because Obamacare would cost me >$20k/year). We don't take vacations
or engage in much of any activity other than work on our house and on RF Cafe. We
don't eat out (McDonald's maybe twice per year), have one vehicle (2011 Jeep Patriot),
and a 1,150 sq.ft., 2 bedroom house. Life has gotten pretty rotten for a lot
of people in the last year and a half - and it doesn't have to be except for radicals
running the show. Hopefully, you are secure in your income, health, and have peace
of mind.
 During the early days of
remote (radio) controlled models - airplanes, boats, and cars - the only way
to legally operate an R/C was by possessing an amateur radio operator's license.
At some point in time around when this article appeared in a 1952 issue of Radio-Electronics
magazine, part of the 27 MHz band allocated to Citizens' Band radio was opened
to low power radio control. Even then, a radio operator's permit from the FCC was
required for use, which in 1974 I paid to obtain (too bad I don't still have it).
My first R/C system, purchased used from a guy down the road who was heavily into
radio controlled models of all sorts, was on 27.195 MHz. It was a 3-channel
Digitron DP-3 system manufactured by OS Digital (in Japan), although there was only
analog circuits in the transmitter, receiver, and servos. The FCC designated five
frequencies for R/C in the 72 MHz band in 1965, then a total of about 60 channels
by the late 1980s. In 2004, the first spread spectrum R/C system was introduced,
operating in the 2.4 GHz ISM band. In 1952, there was not much in the way of
proportional control of movable surfaces - rudder, elevator, aileron, engine throttle,
etc. Motorized servos were just beginning to come to market, but they were basically
neutral, full throw left, or full throw right. It was an electromechanical substitute...
/jobs.htm" target="_top">
![Engineering Job Board - RF Cafe]() 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 /jobs.htm"
target="_top">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...
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Thursday the 9th
 What began
as the "Ohm Confinement" engineering comic series during the Covid farce, when bureaucrats
(including politicians, doctors, administrators, and scientists) destroyed the world's
normal activity by locking people out of public places and insisting on useless
face masks, is now being resurrected as "Adventures of Ohm." The comic's theme is
the brainchild of Dr. Ray Ridley and his wife, Denise, and the drawings are done
by artist Aya Shaheen. Now that the comic face masks are gone, I'm happy to promote
it. Enjoy.
 As with so many aspects of technology, the
beginning phases of television - both black and white (B&W) and color -
had a variety of competing schemes for accomplishing the objective. For the sake
of simplicity, efficiency, and ultimately cost, one solution needed to be agreed
upon by industry and government regulatory groups. Manufacturers came up with different
ways to build their televisions so that the broadcast standards were met, and then
the buying public decide which designs were the best. This article from a 1954 issue
of Radio-Electronics magazine was written by none other than Lee de Forest,
inventor of the first positive amplification vacuum tube (the Audion). He discusses
primarily proposed types of color picture tubes and the raster scan method of an
amplitude modulated, steered electron beam energizing phosphorous dots on the face
of the cathode ray tube (CRT). I have posted many articles on the development of
television systems; a list of most of them is at the bottom of the page. If you
are not already familiar with TV's history...
 If you have ever placed a fixed
resistor in parallel with a potentiometer to reduce the total resistance, then
you are familiar with how you also convert a linear relationship of the wiper movement
with resistance to one that is nonlinear. That is because the equation changes from
Rtotal = Rx:potentiometer (where x is the potentiometer
position) to Rtotal = (Rx:potentiometer * Rparallel) / (Rx:potentiometer +
Rparallel). The graph of it looks like one of the curves in this chart.
Since the total parallel resistance is always smaller than the lowest value of the
two resistances, the greater the ratio of the two is, the more dominant the smaller
resistance value becomes. That means as the potentiometer wiper approaches the minimum
resistance end of its travel, the parallel resistor attached across it has virtually
no effect...
 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 12,000 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.
 Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets
exceedingly high standards of quality, performance and excellent value, and are
100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz.
Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production.
All products are custom designed. We will find a solution and save your time and
cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Wednesday the 8th
 ''The 2022
Youth on the Air (YOTA) Camp will be on the air and streaming online. The campers
will be operating special event station W8Y from the National Voice of America (VOA)
Museum of Broadcasting in West Chester Township, Ohio, as well as from their hotel.
Activation of W8Y will begin on the evening of Sunday, June 12, and conclude at
1 PM EDT on Friday, June 17. Campers will operate the station as they finish projects,
between camp sessions, and during their free time. In addition, dedicated HF station
operating times will be on Monday, June 13, from 2 - 11 PM EDT. Dedicated satellite
station operating times will be on Thursday, June 16, and Friday, June 17, from
10 AM - 1 PM EDT. Earth-moon-Earth (EME) will be in operation on Tuesday, June 14,
and Monday, June 13, from 9 to 11 PM EDT. The opening and closing ceremonies will
be streamed live on the Youth on the Air YouTube channel. The opening ceremony will
take place on Sunday, June 12..."
 You can go into Walmart (or Radio Shack,
when this was first posted) and pick up a pretty decent handheld metal detector
for under $100 these days, but in the 1950s even a rudimentary metal detector was
a rather large and heavy contraption. So unwieldy were they that most had a belt
clip and shoulder straps to help support and manipulate them. That was the situation
facing teen electronics aficionados
Carl and Jerry as they pondered how to leverage their combined technical prowess
to facilitate a thorough combing of the nearby Lake Michigan beach area for treasures
of coins, watches, jewelry, cigarette lighters, and other metallic objects given
up as lost by weekend seekers of relief from searing hot, humid late summer days.
Read on in this 1956 Popular Electronics technodrama to discover how their
innocent plans turned into an adventure that helped local law enforcement officers
nab a wanted man...
 The good folks at
Modelithics invite you to visit
them at Booth 7010 at IM 2022 in Denver, June 19th-24th. "Be sure to register
for RF Boot Camp! This one day course is ideal for newcomers to the microwave world,
as well as marketing and sales professionals looking to become more comfortable
in customer interactions involving RF & Microwave circuits and system concepts
and terminology. This year's RF Bootcamp will include speakers from Keysight, Analog
Devices, Oregon State U., U. of South Florida, and Modelithics!"
 This is part 5 in a series that began in
the October 1951 issue of Radio & Television News magazine (see part
4). Previous articles dealt with
crystal diodes in AM and FM radios, and this article shifts gears by moving
into television applications. Crystal diodes were and are still used in frequency
generation, envelope detection, frequency mixing, and AC signal rectification. Vacuum
tubes could be used for the latter three applications but many physical issues such
as size, weight, power consumption, and heat dissipation proved to be major drawbacks
as designers strived to reduce the size of electronics assemblies, make them more
energy efficient, lower the cost of manufacturing, increase reliability, and decrease
weight. Demands for portability was the motivation for much of the work. Early crystal
diodes could be noisy and fragile if not mounted carefully, but as will all technology,
continual R&D has refined and improved crystals significantly...
RF Cascade Workbook 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.
|
