Yeah, you're right,
almost nobody needs a chart of
vacuum tube schematic symbols, but for the few nostalgic types
who do, here is one from a 1944 edition of Radio Craft magazine. As with
schematic symbols for transistors, these renditions are representative of the general
appearance you will find, but the exact manner in which tube symbols appear vary
greatly. Perusing all the various electronics publications of the day will reveal
New List of Magazine Articles
Here is a list of good articles to pass
the time until the weekend arrives in a few hours. Enjoy.
X. Sheng X. Yuanming
Match Impedances When
Antenna Design Challenges
for New-Generation Nano
Satellites, D. Farr,
MIPI's RFFE: A Standard for
Unifying Mobile Device
J. Ross, V. Wilkerson,
Millimeter Waves Enhance
Military Projects, J.J. DeLisle
Here is a note posted
by Martin Rowe over at
EDN where he had a weird experience with the insulation on his
ESD wrist strap melt away. He is soliciting possible explanations. Have you
seen this type of thing before? The most likely explanation is reaction between
the cord insulation material and the plastic bag in which it was stored.
Fairview Microwave announces the release of their
new family of
25, 50 and 100 Watt attenuators with operating frequencies up to 18 GHz depending
on the configuration. There is a total of 236 new part numbers in this attenuator
release from Fairview Microwave. Attenuation options include 3, 6, 10, 20, 30, 40,
50 and 60 dB models for most connector styles. These attenuators can be ordered
with in-series connector configurations including SMA, TNC, Type-N and 7/16 DIN
As a premier
manufacturer of RF Connectors,
Cable Assemblies and RF Components,
Dongjin TI is highly recognized an RF industry leader in Korea. Our premium products
offer a competitive price, on-time delivery and best quality in the industry. No
minimum order. 1-Day delivery ISO9001, ISO14001, ROHS and MSDS Equivalent product
suggestions with drawings and specification available. VSWR report on request.
"Use it up... Wear it
out... Make it do... Or do without" - what a great slogan! It was coined by
the War Advertising Council during World War II to promote the dual need to
conserve scarce resources and to help keep prices down by not generating excess
demand. Most of us have seen videos or read articles about neighborhood materials
collection efforts to round up old tires, scrap metal, glass, tools, electronics
equipment, cloth and clothing, and many other items that could be recycled for used
directly in the war effort. There was also an undertone of not abetting attempts
by opportunists to profiteer off the war. Government policy did what it could to
control the economy...
today's environment where law breakers seem to have more rights than law abiders,
the electromechanical pyrotechnic tactic used in this story to snare a thief would
have been used by a lawyer to charge
Carl & Jerry (and Parvoo U. dorm mate Benny)
with assault. A moronic judge would likely convict and fine (or jail)
the boys trying to protect their own property and let the actual perpetrator - caught
red-handed - walk. In fact, it we apply contemporary dictates on the treatment of
property trespassers (i.e., the U.S. southern border), after getting
into the car's trunk the law breaker would be given food stamps...
von Braun and his team of rocket scientists are credited with developing the first
useful inertial stabilization platforms for ballistic missiles. The infamous and
formidable V2 rocket wreaked terror upon the heads of Londoners during the latter
days of World War II. It served to keep the rocket in a fixed orientation during
the boost phase of the flight, but did not serve any active targeting function.
Inertial navigation systems, on the other hand, are used to provide both accurate
positional and attitude information for the pilot and to steer the platform to a
predetermined destination. Inertial nav systems are therefore much more complex...
JQL Electronics specializes in
RF isolator and circulator designs
and production. Over the past few years, JQL has expanded its technical capability
in product development. Our engineering
and technical support team has gained extremely
valuable experience in designing products that can meet both high performance requirements
and aggressive cost targets.
call waiting, call holding, speed dialing, conference calling, all of these features
are taken for granted with mobile phone and VOIP phone service and are included
in the base service package. It will cost you extra if you subscribe to a local
POTS (Plain Old Telephone Service) provider. What
is standard now was considered ground-breaking technology in the early1960s. When
phone calls were processed via human operators manipulating patch cords and then
electromechanical relays, it was enough to simply place a successful call and not
be interrupted or disconnected. Once transistorized circuits entered the scene...
and HF Propagation, by Steve Nichols and Alan Melia, is a FREE e-book published
by the Radio Society of Great Britain (RSGB).
Says Mr. Nichols, "I wanted to look at the processes behind ionospheric propagation
and try to explain some of the terms that are commonly used, such as solar flux
index, K index, interplanetary magnetic field (Bz) and many more. The
end result was a series of features that formed a good introduction to the topic.
When I finished, my good friend Alan Melia G3NYK, took over and wrote three more
features on LF propagation – a topic he is very well placed to explain." Thanks
Birsa for letting me know about it.
By 1944, the U.S.
and its Allied partners were occupied full-time beating back the forces of Communism,
Fascism, Socialism, and many other 'isms.' A vast majority of active service members
were men who were either training on domestic soil or fighting on foreign soil.
That left sisters, mothers, and grandmothers to conduct a lot of the business and
work production jobs that historically had been the near sole purview of men. Rosie
the Riveter was a very familiar symbol of that new paradigm, while less known and
celebrated were the women who handled building and servicing electronics products.
I have posted many articles that appeared in magazines during World War II
showing the various scenarios in which
women contributed mightily to the war effort, even without...
RFMW announces design and sales support for
Delta Electronics RF connectors and adapters with over 550 parts
that are military M39012 and UG designations. RFMW has a QPL Military Cross Reference
guide for the mil spec numbers to the equivalent Delta Electronics part numbers.
Also Delta Electronics has a catalog with detailed information indexed by description
and QPL Number. Full vertical manufacturing capabilities including CNC machining
"One of the biggest
causes of hard drive crashes today is a Congressional subpoena." - Anon
If you like world maps that are superimposed
with various statistical data, then you will appreciate this collection of 40 such
renderings. They are presented without verification, but it is probably safe to
assume a reasonable degree of accuracy since very few would benefit from a political
bias. This one shows earthquake activity, while others show population density,
economic center of gravity shift (I could comment at length on that one),
Internet usage vs. time of day, coffee consumption per capita, and much more. My
favorite is second to last (#39) which shows the literal Chinese translations
of given European country names.
Here is a very useful
article on the benefits and technical challenges of
stacking antennas. It avoids rigorous mathematical analysis and
instead presents recommended guidelines and includes some very nice measured antenna
patterns (no computer-generated predictions in 1958)
of the various configurations. The authors discuss radiation pattern changes based
on horizontal versus vertical stacking, and a combination of both. This is the first
of a series written by engineers at the Scala Radio Company.
is based on the information presented in Stimson's
Introduction to Airborne Radar, 3rd Edition, by Hugh D. Griffiths,
Christopher Baker, and David Adamy. The publisher was not kidding when he stated,
"recognizing that people who have an interest in airborne radars love airplanes,
dispersed through the book are photos and renderings of radar-bearing aircraft from
all over the world." If for no other reason, Stimson's book is a good one to leave
on your desk or coffee table as a way-cool picture book for your friends to peruse
while visiting. Introduction to Airborne Radar is in every sense a text
designed to turn the electronics neophyte who has a reasonable grasp of algebra
and physics into...
Specializing in the
repair of spectrum and network analyzers.
A leading dealer of new and reconditioned test and
measurement equipment. We buy, sell, rent,
lease, repair and calibrate all types of general purpose test and measurement equipment.
other certificates have already, been awarded to individuals and companies. Possibly
the most notable figure to receive one is
Dr. Harold H. Beverage, old-time radio researcher and inventor,
now an associate director of the RCA Laboratories. The Beverage Antenna, very familiar
to amateur radio operators, is a simple but efficient, highly directional, non-resonant
antenna that consists of a single straight wire of one or more wavelengths that
is suspended above the ground. It is orientated parallel to the direction of intended
reception. One end is terminated to ground through a resistor, and the other is
connected to the receiver. The following quote comes from the patent...
energy does it take to power a
pendulum-regulated, gravity-driven mechanical clock for a full
day? I decided to use my hand-crafted grandmother clock as a test bed. Three 5-pound
lead weights provide motivation for countering the friction of all the gears and
chime hammers. Calculation of the energy consumption is a Physics 101 problem since
the familiar governing equation is that of potential energy in the Earth's gravitational
field: All three weights were reset to the top of the travel and a reference measurement
was made. All three weights drive the mechanism in unison, so they fall the same
amount over time. Since I was only interested in the change in potential energy,
the change of height, not the absolute height from the Earth's center...
To be successful
at this week's
RF engineering crossword puzzle you will need to be familiar with
receiver design issues. All of the words are directly related to science and technology,
so the entire crossword should be enough of a challenge to make you feel good about
completing it. Then again, all of my puzzles are like that - no numbnut words or
Communications Commission claimed in 2013 to be receiving more than 30,000 applications
per year for commercial broadcasting licenses. That covers the gamut from AM and
FM to television, Low Power FM, Low Power TV, translators and booster stations,
as well as some non-commercial stations for educational purposes. Inexpensive, turnkey
broadcast station equipment make entry into the realm very affordable. Accordingly,
there are many stations vying for space in a very crowded section of the electromagnetic
spectrum. Contrast that to the year 1932 list of broadcasting station in the U.S.
for your cellphone's cover are not new, but this model from
OwnFone™ has a unique
twist - its case is fabricated with a 3D printer that can create a keypad with Braille
buttons for the blind (or sight-impaired). The OwnFone™ concept is
one of simplicity and special use since it only functions as a phone. You cannot
even receive voice mails or text messages on it (OMG!).
If you choose the Braille, Child, or Senior model, it only accommodates up to four
buttons, each with a specific phone number to be dialed, but a standard 3x4 numeric...
Here is an amazing
Sherlock Ohms story that you will appreciate. It is a great bit of detective
work that required the author to enlist assistance from a couple Ham radio guys
at work. I was surprised at the ending because of how I interpreted the title.
are a great source of levity to take you away from the day's normal flow of events.
My favorite comic strips contain themes that relate to familiar scenarios or that
catch me by surprise with their message.
Technically themed comic strips like this collection from
Radio-Electronics are particularly welcome, but I do not appreciate gratuitous
meanness and never care to see death, dismemberment, or gore. Call me a prude, but
I'm shocked sometime by what appears in the daily newspaper comic strips...
Not everyone who
visits RF Cafe is a seasoned engineer or technician. Some are just getting into
electronics as part of a career path and/or hobby endeavor and appreciate the availability
of entry-level information. As some oft-quoted sage-type person famously said, "A
journey of a thousand miles begins with the first step." Accordingly, here is a
short article explaining the basics of
Zener diode operation. Thanks for your indulgence - or you're
welcome - depending on your experience level.
Tech Article Roundup
Many of the technical article writers must
be on vacation (or holiday, depending on your locale) because the normal
flow seems to be slowing. Nevertheless, there are a few worthy of mention, IMHO,
that have appeared in the last couple weeks.
Provides an EMC
Overview, M. Rowe
Anticipating Future Military
MIMO, J-J DeLisle
Living a Quite Life (p32),
Satellite Communication Ground Segment and Earth Station Handbook, by Bruce
Elbert, is an updated and expanded second edition reflects the state of earth station
design and ground segment architecture. From international telephone network gateways
to direct broadcast home receivers, today's broad range of ground systems and devices
require satellite communication engineers and business managers to have a broad
and sound understanding of the design and operating principles of earth stations
a design engineering position with Google is (or at least was) notoriously
difficult because of some of the tests that are administered - depending on the
hoped-for job. Skills in logic, creativity, problem solving, and fundamental mathematics
and science are among the capabilities that must be demonstrated. IBM was known
to have tough entry requirements for customer field service representatives back
early days of computers - for technicians as well as for engineers.
"A man who can think his way through a problem can learn electronics, but a person
Carl and Jerry use a pair of General Electric pnpn junction photoelectric
switches to exact revenge on an engineering student 'friend' at Parvoo U. It involves
embarrassing the guy in the presence of his YL (Hamese for young lady)
date. The switches, per Jerry's tutelage, work like a silicon-controlled rectifier
(SCR), except light is used to trigger the conduction path rather than an electrical
gate signal. The devices are "solid-state kissing cousins of vacuum tube thyratrons."
That's not necessarily the way...
S., of Poway, CA, is the RF Cafe Book Drawing winner for July 2014. Matthew chose
Radio Frequency System Architecture and Design, by John W. M. Rogers,
Calvin Plett, Ian Marsland (Graciously provided by
Artech House). Each month
I randomly select one or two names from the list of people who buy my products,
write to point out errors in the website, or otherwise send me useful information.
Radio Systems Corporation
(RSC, PetSafe, Invisible Fence, SportDOG) is a growing international
organization that offers a variety of openings at any given time. Our company needs
an RF design engineer to lead development of new products and sustainability of
existing products. Wireless pet fences, training collars, and location control devices
are among our well-known pet-friendly offerings. If you are interested in working
at RSC, please look at the full Sr. Staff RF Design Engineer job description.
case such things interest you, this first-person story of a
ship's wireless operator, or "op," - the guy who manned the radio
room - provides a little entertainment and insight into transoceanic travel in the
1930s. The author's trip was made less than two decades after the demise of the
'unsinkable' RMS Titanic, where surviving passengers and crewmen were saved partially
due to the heroics of the telegraph operators. Having never traveled on the water
beyond the Chesapeake Bay, I wouldn't know how to compare today's voyage with those
LadyBug Technologies' new LB5908L Power Sensor
measures RF power at frequencies from 9 kHz to 8 GHz, making it ideal for source
calibration and EMC testing applications. The sensor has excellent sensitivity and
measures from -60 dBm to +20 dBm. The fully self-contained sensor has three interfaces,
giving it new never-before -available connectivity. Customers can connect to the
sensor using USBTMC, USB HID, or the optional SPI/IIC interface
are a hoax." - Lord Kelvin (after whom the Kelvin temperature scale is named
in honor of his determining the value of absolute zero), nee William Thomson.
He also, in 1895, famously noted, "Heavier-than-air flying machines are impossible."
So much for otherwise really smart guys always being right in their predictions.
Phase Matrix designs and manufactures RF and
microwave T&M instruments and is a subsidiary of National Instruments. Our array
of products include EIP-brand
PXI-based microwave products, and VXI-based
microwave products. Our 50,000 square-foot facility includes an R&D lab, clean
rooms, and test stations.
Electronics offers the industry's largest portfolio of high-performance standard
and customized RF and microwave filters and filter-related products for military,
commercial, aerospace and defense, and industrial applications up to 40 GHz. Anatech
has released new designs for a 900 MHz cellular bandpass filter, 885-909 / 930-954
MHz cavity duplexer, and a 900 MHz ceramic bandpass filter.
Along with a new
week comes a new set of career advice tips from the 'experts.' Most of these bits of sage
opinions are applicable in general, but they will tell you that tailoring the application
to specific situations is the key to success. Duh, like you didn't know that. Although
I usually approach these advice columns with a healthy degree of skepticism... Here
are a few more useful articles:
α - The
Five Best Times to Ask for a Raise
Simple Remedies for Common but Awful Job-Hunting Blunders
γ - 6
Types of Interviews and How to Nail Them
δ - Double
the Number of Recommendations on Your Profile With Style <more...>
Do you ever wonder
what it is that causes the figurative 'light bulb' to go on over someone's head
when a brilliant ideas occurs that solves a
Legend has it that Isaac Newton devised his theory of gravitational attraction after
getting bonked on the head by an apple. Percy Spence supposedly came upon the idea
of using microwaves for cooking food when a chocolate bar in his pocket melted when
he stood too close to a poorly shielded magnetron. George De Mestral invented Velcro
while painstakingly picking cockleburs out of his dog's fur. Alexander Fleming discovered
penicillin on mold growing in an unattended Petri dish. Dr.s Arno Penzias and Robert
Wilson found the cosmic microwave background signature...
ground-breaking, paradigm-changing, outside-the-box 8-track tape came the
4-track tape, itself a marvel of modern technology. This brief
announcement regarding its imminent introduction to the music storage and playback
world appeared in the July of 1958 of Radio-Electronics, barely a month
before my introduction into this old world. Many people did -and still do - scoff
at the mention of an 8-track tape deck and assorted tapes. I actually preferred
them over the snobbishly preferred cassette tape because unlike cassettes where
you had to run serially through each song...
My first major
high fidelity stereo system purchase came during my senior year of high school
(1976 - ugh!) when I had saved enough money to buy a combination AM/FM
receiver, 8-track tape deck,
turntable, and two speakers with separate woofers, midranges,
and tweeters. At the time I thought the setup might impress friends and relatives...
until I learned quite quickly that 'serious' stereo sound connoisseurs decidedly
did NOT have equipment with "Reader's Digest" logos on it. Oh well, the price seemed
like a really good bargain to me give the promised tonal superiority. Compared to
the clock radio I used previously for my music listening sessions...
Amateur Radio Crossword Puzzle, as do all my crosswords, uses
only technical type words pulled from a hand-assembled dictionary that has been
added to for over a decade. You will find no other crossword puzzle like it anywhere
on the Internet.
the procurement cost of
promethium 147 never fell low enough to make it affordable by
the masses. If it had, though, we might all have been wearing nuclear-powered Elgin
National Watch Company timepieces in the last century rather than Timex. Beta particles
from the radioactive decay of promethium 147 impinge upon special crystalline components
that generate enough electricity to power a watch for five years or more. I wonder,
had it been successful, how long it would have been before 'that persistent rash'
Luxury watch maker TAG Heuer
has introduced a cellphone that charges itself via a visually undetectable photovoltaic
layer within its sapphire crystal screen. According to a
GizMag article, an hour of direct sunlight (hopefully not on your car's
dashboard) will recharge the
Meridiist Infinite's battery by up to 30%. You'll need to contact TH about the
price, and you'd better hurry because only 1911 of them will be made - ostensibly
to commemorate the date of their first patent dashboard "Time of Trip" auto and
aircraft recorder, but is the company's owner really a closet
Colt 1911 pistol fan?
Amplifier Solutions Corporation (ASC) is a
designer and manufacturer of RF &
amplifiers for the military and commercial markets. ASC's thick film hybrids
utilize GaAs FET, silicon bipolar transistor and MMIC technologies to achieve low
to medium power output in the 300 kHz to 6 GHz frequency band. ASC offers
thin film designs that operate up to 20 GHz.
NI (formerly AWR Corporation) has
launched the NI AWR Design Environment™
E-Learning Portal to give current users of NI AWR software the
ability to learn more about the powerful tools, technologies and applications of
the software as their time and interest allows. The portal offers jumpstart
training videos that cover all aspects of the software (from harmonic balance
to electromagnetic analysis), educational teaching materials