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 Google Search box
at the top of every page
Z-Comm's Ultra Wideband VCO Tunes from 2.7
to 5.4 GHz
V600ME31-LF operates from 2700 to 5400 MHz with a tuning
voltage range of 0-24 Vdc. This octave tuning VCO features
a typical phase noise of -107 dBc/Hz @ 100 kHz offset
and an average tuning sensitivity of 140 MHz/V. The
V600ME31-LF is ideal for satellite communication applications.
It is designed to deliver a typical output power of 7 dBm into
a 50 ohm load while operating from a 5 Vdc supply.
Boston Marathon Chechnyan Terrorists Kill
a bomb strapped to his chest, one of the Boston Marathon suspects
was killed early Friday after he and his accomplice brother robbed
a 7-Eleven, shot a
police officer to death, carjacked an SUV and hurled explosives
in an extraordinary firefight with law enforcement, authorities
NBC News." Don't bother looking in the article for mention of
the bombers being Muslim or for the word 'terrorist.' The news media
is still hoping the two are
white guy Tea Party members. I'll be visiting a state today
where my CC permit is not recognized so I'll just have to hope there
are no problems along the way. We are screwed.
Sherlock Ohms: Car Radio Fires up Check
controls, evaluation kits and master development systems feature
straightforward hardware configuration and clear documentation,
making it simple for engineers and hobbyists to integrate wireless
features without the hassle and expense of engineering RF functionality
from scratch. We also offer design services including board
layout assistance, programming, certification advice and packaging
design. "Wireless Made Simple"
Please Visit Apex Wireless in Appreciation
of Their Support
1985, Apex Wireless has offered
engineering, and design services focusing on high-performance,
cost-optimized products that employ wireless RF transmitters, receivers,
and transceivers. To complement our RF design expertise, we work
with local experts in DSP, ultra low power design, packaging, certification,
Fundamental Crystal Control for Ultra-High
radio frequencies continued to increase during the early years of
'wireless' development, the use of quartz crystals as a stable reference
source ran into a physical limitation because as crystal slices
reached a certain thinness, overtone and subharmonics appeared that
caused problems in circuits. A new mineral called
tourmaline saved the day. With an elasticity much greater than
quartz, tourmaline is able to vibrate at higher fundamental frequencies
for a given thickness. Since that time, science has provided the
means for utilizing the much more abundant quartz crystals in overtone
modes so that tourmaline is not required. At the time, though, it
was a much-welcomed alternative.
Why, Strategic Air Communications
could take this article from 1950 and substitute 'drone' for 'intercontinental
bomber' and it would do a good job of describing present-day capabilities
for global defense based on modern communications. Get a load of
the photo of an Air Force technician doing repair on a radar chassis
- using a Weller soldering gun! Compare that to today's method of
circuit repair that often requires a hot air tool, tweezers, and
an eye loupe. Actually, I can remember replacing fried resistors
in my USAF group's radar system using just such a soldering gun.
Most of the chassis had point-to-point connections where components
connected to bifurcated terminals or terminal tab strips. The
Ground Controlled Approach (GCA) mobile trailer pictured looks
a lot like the Equipment Trailer for our MPN-14 search radar system,
except the search radar antenna was...
Hittite Launches New Programmable BW LP
Microwave has introduced the
HMC1023LP5E, a new addition to its IF/Baseband Processing
integrated circuit product line. A 6th order, programmable bandwidth,
fully calibrated dual Low Pass Filter (LPF), the
HMC1023LP5E features programmable 0 or 10 dB gain and supports
arbitrary user programmable, bandwidths from 5 MHz to 72 MHz. When
calibrated, the programmed bandwidth is accurate to within ±2.5%.
A built-in filter bypass option enables wider bandwidth while maintaining
programmed gain and common mode control settings.
PMI Intros 2.0 to 18.0 GHz Low Noise Amplifier
PEC3-33-218-20-15-SFF-HS-E is a 2.0 to 18.0 GHz Low Noise
Amplifier that provides greater than 33 dB of gain while maintaining
a maximum gain flatness of ±2.0 dB maximum over the operating
frequency. The noise figure is 4 dB typical and offers an OP1dB
of +20 dBm minimum and an OIP3 of +30 dBm typical. The
operating voltage is +15 VDC and the current draw is typically
of Passive RF Front-End Components in SoCs, by Hooman Darabi
and Ahmad Mirzaei. Examining the most important developments in
wireless RF front-ends, this book describes and evaluates both
active and passive solutions for on-chip high-Q filtering, and explores
M-phase filters in depth. An accessible step-by-step approach is
used to introduce everything an RF designer needs to know about
these filters, including their various forms, principles of operation,
and their performance against implementation-related imperfections.
Real-world examples are described in depth, and detailed mathematical
analyses demonstrate the practical quantification of pertinent circuit
Please Thank AWR for Their Continued Support
the innovation leader in high-frequency EDA, provides software solutions
that maximize user productivity for the design of high-frequency
ICs and communications systems for the aerospace / defense, semiconductor,
computer, consumer electronics, and telecommunications markets.
Visual System Simulator,
Analyst are amongst the popular programs offered. Free trial
downloads are available.
Nobody Commented on My April Fool's Article
it has been two weeks and not a single person commented on my
2013 April Fool's faux article for the year. I would like to
think it is because the ruse was so believable that it did not arouse
suspicion, but the greater likelihood is that A) no one cared enough
to read it or B) it was so apparent that comment would be a waste
of time. It was titled, "Method
for Selectively Creating Fissile Mass Fragments."
Using the Decibel
some reason even a few really good technicians and engineers have
decibels. Ever since learning about, and truly understanding,
logarithms, I have appreciated the convenience of being able to
use addition and subtraction to perform multiplication and division,
respectively. Decibels, being logarithms, have always made perfect
sense to me. Even the difference between voltage dBs and power dBs
has been easy to remember because of the power rule of logarithms,
log (AB) = B·log (A). Calculators
offer little help when you don't comprehend the basics of decibels.
In 1955 when this article was written, people used tables of logarithms
rather than punching calculator keys. Mathematicians and appointed
underlings spent their lives generating tomes of logarithms. Historians
have found many errors in those tables while doing research, but
no ships ever sailed off the edge of the Earth due to a computational
error based on them. On a side note, I recall a day when I was a
teenager where I was listening to...
Popular Electronics Crossword Puzzle
is a vintage crossword puzzle from the October 1957 edition of
Popular Electronics. Like the weekly
from RF Cafe that uses only relevant technical words, this one contains
mostly words relating to electronics.
Many Thanks to American Microwave for Support!
Microwave Corporation (AMC) uses a state-of-the-art clean room to
manufacture all of it's products, as well as a fully automated machine
shop. AMC is a leader in the design and manufacturing of DC to 40 GHz
solid state control components for commercial and military grades,
including amplifiers, coaxial switches, and attenuators.
Single Layer Coil Design Chart
layer coil design charts (aka nomographs) are a dime a dozen
on the Internet. Here is RF Cafe's 0.083¢
contribution. A couple examples of usage are included. You're welcome.
Pasternack Intros Semi- Flexible Precision
Enterprises adds new line of semi-flexible,
hand formable coax cable assemblies up to 18 GHz. Pasternack
Enterprises’ new formable RF cable assemblies are hand formable
semi-rigid replacements that are an ideal alternative to costly
preformed coaxial assemblies. These formable semi-rigid cables are
dimensionally and electrically similar to their semi-rigid counterpart
and have a tinned-copper-braid outer shield that provides excellent
RF shielding, greater than 100 dB. The hand formable cable
assemblies from Pasternack do not require special tooling to shape
or reshape the assemblies and can be formed more than once without
damaging the outer conductor.
Microwave Corporation has launched two high performance GaAs MMIC
I/Q mixers which further complement Hittite’s extensive mixer product
portfolio while providing frequency coverage for a broad range of
applications spanning 8 to 28 GHz. The
HMC1063LP3E and the
HMC1056LP4BE are GaAs MMIC I/Q mixers in compact leadless "Pb
free" SMT packages, which can be used as either image reject mixers
or as single sideband upconverters. The mixers utilize two standard
Hittite double balanced mixer cells and a 90 degree hybrid fabricated
in a GaAs Schottky diode process. A low frequency quadrature hybrid
is used to produce a 1000 MHz LSB IF output.
Please Visit Q-par Angus in Appreciation
Angus designs and manufactures
components and subsystems across the radio frequency spectrum,
with specialisation in microwave & millimetric systems. We design,
build and calibrate our products to the highest engineering standards.
Custom products designed to your specifications available.
Tax Day 2013: RF Cafe's *Fair Share*
Freedom Day for this year is April 18 - five days later than last
year. Today, April 15, is the day in America by which half the population
gets to pay its *fair share* to the government in the form of income
taxes (the other half pays no income taxes). Oh, excuse me, it is
when we are "asked" to pay our fair share. Don't you love the "asked"
term ...as if we have the option of refusing without going to jail?
Six envelopes are pictured here that contain various tax mailings
for Melanie and me: one each to the IRS for income tax and Q1 estimated
income tax, state income tax and Q1 estimated income tax, local
income tax and estimated income tax, plus a local services tax.
The local services tax is just for the 'privilege' of working -
I kid you not. After paying federal, state, and local income taxes,
sales taxes on all we bought (including gasoline), utility taxes,
taxes on savings, property taxes, school taxes, etc., etc., etc.,
our total 'fair share' works out to 37.6% on adjusted gross income.
So, more than a third of our income was paid in taxes. Just our
federal adjusted gross tax alone worked out to 26.6% of adjusted
gross. By comparison, according to Whitehouse.gov, "The President's
effective  federal [adjusted gross] income tax rate is 18.4%..."
Sherlock Ohms: Least-Obvious Signals Sometimes
Ohms is a regular feature of Design News that presents
submissions from readers about troubleshooting challenges and how
they were solved. This story titled "The Least-Obvious Signals Sometimes
Bite You." When is a digital circuit not a
digital circuit? When somebody forgot that ultimately everything
is an analog circuit, and things like L, R, and C combine in the
most insidious ways to derail a design...
Therapeutic Horse Riding Mounting Platform
daughter, Sally Cochran, and her husband, Matt, owns and operate
the Equine Kingdom Riding Academy on their farm in Greensboro, North
Carolina. Sally is currently a Level 2 ARIA instructor certified
in Recreational Riding and Hunt Seat on the Flat, a member of AQHA,
NCHJA, and PATH Int'l. She became a PATH certified instructor in
November 2012. In order to fully implement a
therapeutic riding program at Equine Kingdom, it was necessary
to install a
mounting platform and access ramp that can be used to assist
people in wheelchairs and with other disabilities in mounting and
dismounting horses. Commercially made platforms/ramps start at around
$5,000, which is far too expensive for an operation like Equine
Kingdom. So, I researched some of the government's handicap access
requirements and designed the mounting platform and ramp shown below.
As you might expect, there are no shortage of regulations...
very hard to find a work ethic better than that in the Upper Midwest."
-- Bob Whitney, Itron, VP of manufacturing. This newspaper
article interview reports on
history in Waseca, MN, after beginning as
EnScan in the early 1990s. I was there as an RF engineer in
1992 right after the break-off from EF Johnson, and during the move
to the new facilities.
Grant Whissemore, mentioned in a 2012 story, was once a crewmember
Edmond Fitzgerald (before is sunk, fortunately). I think I still
have my "2 Millionth ERT" T-shirt somewhere.
Science & Engineering Crossword for
April 14, 2013
Sunday I create a
crossword puzzle using a word list that I personally created
and added to during over a decade of making puzzles. All of the
words are related to engineering, science, mathematics, chemistry,
astronomy, etc. There are no numbnut clues about movie stars or
clothing designers. Enjoy.
Radar: The Silent Weapon of World War 2
the history of radar intrigues you, then you will not want to miss
this article titled "Radar:
The Silent Weapon of World War 2," from the October 1945
edition of Radio News. There are a couple dozen photos
of early radar equipment installations on land, ships, and aircraft.
Radar pioneers Dr. A. Hoyt Taylor, Chief Consultant and Chief Coordinator
of Electronics at Naval Research Laboratory, and Leo C. Young are
pictured reminiscing over the "scope" of radar's history
beside the first radar set at the Research Laboratory. In 1922,
while experimenting with communications equipment for the Navy,
the two men made the initial discovery of distortion in radio reception
caused by the intrusion of objects between the transmitter and receiver.
Working from this discovery, they and a number of associates made
great strides forward into the vast sphere of scientific fields
covered by the word "radar" today. Do you see the name(s)
of anyone you know?
Many Thanks to PMI for Continued Support
Monolithics Industries' organization has been setup to Design,
Develop, Manufacture, Test, and Market complex state-of-the-art
Hybrid RF MIC and MMIC Components, Supercomponents, and Subsystems.
Unique products for applications in space, military, commercial,
telecommunications, and consumer electronics systems. DC- 40 GHz.
Bliley Technologies Intros Ultra Stable
Surface Mount TCXO
Technologies is pleased to release an industry standard 5mm x 7mm
TCXO in a SMD hermetically sealed package. This series of TCXOs
threatens OCXO frequency vs. temperature stability without the power
consumption or cost. The frequency vs. temperature stability starts
as low as ±50ppb. In addition to outstanding Frequency vs. Temperature
stability this series of TCXO offers excellent phase noise at 10 MHz
of -125 dBc at 100 MHz offset and a floor of -150 dBc.
Weekly Job Tips
are a few new employment news articles that you might find useful
if you are looking for or considering looking for a new job, or
for that matter looking for ways to improve your current situation.
6 New Books Added for Selection by Monthly
to the generosity of both
Cambridge University Press, I am able to offer a variety of
engineering books for selection by
winners. Many of the books I use as a basis for
RF Cafe Quizzes. Six new titles
were just added to the pool of available books: - Introduction
to Antenna Analysis Using EM Simulators - Digital Front-End
in Wireless Communications and Broadcasting - Handbook
of RF and Microwave Power Amplifiers -
Introduction to Modern EW Systems - Optical
Antennas, Integration of Passive RF
Front-End Components in SoCs - Handbook
of RF, Microwave, and Millimeter-Wave
An Experimental Station on Wheels
high-tech vehicle you see here was state-of-the-art in 1935 when
engineers at the
Cruft Laboratory at Harvard University outfitted it to do radio
research. Clad with copper and chromium fittings, the vehicle contained
transmitting and receiving equipment along with various test equipment
that included a high stability frequency reference. In the article
a 'tungar' charger is mentioned. A tungar vacuum tube is a high
current rectifier with a tungsten element and an argon
Misunderstanding of Precision
you have a degree in engineering or science, chances are were instructed
on the proper method for reporting numbers in terms of precision
and accuracy. The government has long been the whipping boy for
examples of abuse. If you think that might have prompted corrective
action, you would be wrong. Our public science organizations like
NASA, NIST, NOAA, NIH, et al, do a respectable job of reporting,
but the other agencies display their ignorance on a regular basis.
A couple days ago, DHS(those fine folks who perform cavity searches
at airports) issued a solicitation for
bagpipes and assorted accessories (we
have evidently $ for bagpipes but not the Blue Angels). The
document mentions "a small business size standard of 500.00 employees."
What do the employees that comprise the decimal point portion of
the number look like? I think we can guess what will be done with
this ordered item: "Black waxed bagpipe hemp." Maybe they
should add a few bags of Doritos to the order for when the users
inevitably get the munchies.
Thanks to 3Gmetalworks for Continued Support!
1994, leading wireless electronics companies have relied on 3Gmetalworx
to deliver cutting edge solutions for advanced
RF/EMI PCB-level shielding
requirements. From prototyping and design services to JIT manufacturing
supply, our clients depend on us to provide a seamless service pathway
supporting entire product lifecycle. All our shields can incorporate
these features, as well as your custom needs: Engagement Tabs, Trace/Component
Relief, Tuning/Access Openings, Thermal Relief
WaRS Shoots Down Drone Using Laser
Sea Systems Command, with support from Naval Surface Warfare Center
Dahlgren, for the second time successfully tracked, engaged, and
destroyed a threat representative
Vehicle while in flight. This marks the first Detect-Thru-Engage
laser shoot-down of a threat representative target in an over-the-water,
combat representative scenario. Comments left by low-information
viewers criticize the accomplishment because a slow-flying drone
target was used vs. a real-life target like a missile. These are
the same types who said the Strategic Defense Initiative
(aka 'Star Wars') would never work,
but now the technology regularly intercepts rockets fired from Gaza
into Israel. Moving object tracking and targeting systems, among
other aspects of the research, has benefitted many technologies
from automatic car parking to Earth-threatening asteroid monitoring,
and, eventually, interception.
Hand Soldering and Circuit Board Repair, by H. Ted Smith. Straightforward
and easy to understand, the 6th edition of Quality Hand Soldering
Circuit Board Repair has been thoroughly revised to provide
readers with the most up to date information in the industry. Focusing
on the production and repair of circuit boards, this text begins
with the basics of soldering and the requirements for a reliable
solder connection. Readers are then guided through a variety of
circuit board repairs, from conformal coating identification and
removal to different types of track/pad repairs, burn repairs, and
edge connector repairs. This step by step reference book provides
readers with the skills and knowledge needed to remain competitive
and in accordance with international standards.
AWR's Sherry Hess to Co-Chair MTT-S Women
Corporation, the innovation leader in high-frequency EDA software,
is proud to announce that Sherry Hess, vice president of marketing
and long time advocate for women in engineering, has been named
Women in Engineering (WIE) within the Institute of Electrical
and Electronics Engineers (IEEE) Microwave Theory and Techniques
Society’s (MTT-S) Membership and Geographic Activities (MGA) organization.
New Version of Optenni Lab
Ltd announces a new version of the
Lab matching circuit optimization and antenna analysis software
featuring a unique easy-to-use simultaneous multiport matching capability
for antennas and other RF applications. The work of an antenna engineer
is becoming increasingly complex due to the growing number of radio
systems, frequency bands and antennas. Especially the introduction
of diversity and MIMO technologies increases the complexity of antenna
design in mobile devices. At the same time, the mobile companies
are striving to reduce the design times of mobile devices and to
reduce the total antenna space.
The Audacity of Hopelessness
News just crossed the wires stating that the
Blue Angels and the Thunderbirds
airshow teams have been grounded for at least the rest of the year
due to a phony "sequestration!" Will these @*%# politicians stop
at nothing to heap crap on American pride and tradition? We seem
to have plenty of money for endless Executive vacations, golf games,
and parties on the taxpayer dime, but not enough for the U.S. Navy
and Air Force show teams that demonstrate the best we have to offer?
Meanwhile we give million$ to countries who spawn suicide bombers
that target the U.S. Here are three programs listed prominently
on the AF.mil website that no doubt
receive ample funding: - Sexual Assault Prevention &
Response - Suicide Prevention - Air Force Diversity.
I believe America is doomed, done in by an unopposed
"It's Déjà Vu All Over Again"
is probably Yogi Berra's most famous line, and is the first thing
that came to mind today when I read in the local newspaper where
GE Transportation here in Erie, Pennsylvania, plans to layoff
950 production and 100 management employees. An additional 200 "temporary"
layoffs could also occur. Rumors have been in the works for a couple
years regarding an eventual total plant closing, since a new plant
with the same capability (and more) was being established in Fort
Worth, Texas. The Erie location is totally unionized, and Texas
is a Right-to-Work state (union membership not mandatory). In an
effort to be "globally competitive," labor rates must be kept as
low as possible - for everyone, not just production workers. Texas
also has no income tax, which helps keep wages low as well. Property
taxes in Erie are quite high, typical of the Northeast...
NASA Chief: USA Will Not Go to the Moon
it is time to remove the "S" from NASA. The word "Space" is being
less and less associated with our once-great agency. It seems now
the moon is too high for American scientists and engineers to reach.
NASA chief Charles Bolden declared at a joint meeting of the Space
Studies Board and the Aeronautics and Space Engineering Board that
is not going to the moon with a human as a primary project probably
in my lifetime." Instead we will play supporting roles for China
and Russia in their missions.
astronauts already are humiliated into hitching rides to the
International Space Station (ISS) from
those countries while we transfer technology paid for by our taxpayers
to them. We have no manned space vehicle, many telescopes and unmanned
spacecraft projects are shutting down, and NASA funds are diverted
Mission to Planet Earth. Not to worry, though, at least a NASA
outreach to the Muslim world - a religious group, BTW - is in
After Class: Working with Phase-Shift Oscillators
is an old adage that goes thusly: "If you want to build an oscillator,
design an amplifier. If you want to build an amplifier, design an
oscillator." Its basis is the difficulty that can be experienced
in obtaining the right combination of feedback phase and amplitude.
Of course experience, use of simulators, and careful circuit construction
minimize the opportunity for validating that saying. The basic requirement
for an oscillator is feedback from the output to the input that
is in-phase and great enough in amplitude to maintain, via the amplifier's
gain factor, a constant output level. Tuned L-C (inductor-capacitor)
tank circuits are often used as simple frequency-determining elements
because of their combined resonance characteristics.
Phase shift oscillators are a type of oscillator that can be
built without inductors. Instead, they rely on the phase shift of
a series of capacitors and resistors to obtain the 180-degree phase
shift needed from output to the input to sustain oscillations. Frequency
control is not typically as stable as with a tank circuit or a crystal,
especially as temperatures change...
PS-360-DC-IR-9G10G is a
10-Bit digitally controlled 360 degree phase shifter that operates
from 9.0 to 10.0 GHz. This model offers low insertion loss
of 7.5 dB and a phase shift accuracy of ±0.6 degrees typically.
The typical switching speed is 300 nsec and operates with input
power levels up to +20 dBm. This model requires a single voltage
supply of +12 to +15 VDC with a current draw of 40 mA.
Other frequency ranges are available.
Many Thanks to Cross RF for Continued Support
is a manufacturer of microwave
coax cable assemblies. High volume processing. RG, LMR equivalent
flex to semi-flex and semi-rigid cables for most connectors available.
Attenuators, terminations, dummy loads. Military and commercial
products. Average lead-time of custom cable assemblies is one week.
Introducing WaveXorb A 3Gmetalworx Solution
business since 1994, 3Gmetalworx is an industry leading supplier
of application-specific RF/EMI PCB-level shielding solutions. We
are a service-oriented enterprise focused on serving a global clientele
with application-specific solutions for their needs. Based in the
industrial heartland of Ontario, Canada, we ship millions of shielding
components per year. Building on the success of our PCB-level shielding
solutions 3Gmetalworx is pleased to introduce the
of RF/Microwave Absorbers. We look forward to applying the same
customer focused principles to serve valued clients with needs in
the absorber market. By providing a synergistic solution 3Gmetalworx
looks forward to becoming a more valued supply partner to our valued
clients. WaveXorb absorbers are available in many standard formulations
which meet exacting client performance requirements.
consensus … the process of abandoning all beliefs, principles, values
and policies in search of something in which no one believes, but
to which no one objects; the process of avoiding the very issues
that have to be solved, merely because you cannot get agreement
on the way ahead. What great cause would have been fought and
won under the banner 'I stand for consensus'?" -
Margaret Thatcher, Prime Minister of Great Briton, 1979-1990
W1AW Will Help YOU Become a Ham
the call sign of American Radio Relay League
(ARRL) founder Hiram Percy Maxim, lives
on long past his death in 1936 as the call sign of the official
ARRL broadcast station located in Newington, Connecticut. Two
of the ARRL's main qualifications for status as a 501(c)3 entity
are its public services and educational aspects. Broadcasting practice
Morse code messages has always been a service
(and educational tool) provided for
Amateur radio operators of all statuses from rank beginner working
toward his/her first license to the seasoned 50 wpm veteran
bugmeister (code proficiency is no longer
a requirement for any license level). The people and equipment
have changed since the article appeared in a 1957 edition of Popular
Electronics, but the fundamentals have not.
Electrical Engineering Crossword for April
Sunday I create a
crossword puzzle using a word list that I personally created
and added to during over a decade of making puzzles. All of the
words are related to engineering, science, mathematics, chemistry,
astronomy, etc. There are no numbnut clues about movie stars or
clothing designers. Enjoy.
Please Thank Alliance Test Equipment for
Test Equipment is a trusted source providing sales, rentals and
leasing of refurbished electronic
test and measurement equipment to the R&D, manufacturing
and quality assurance industries. We carry a full range of used
test equipment from manufacturers such as Agilent, Anritsu,
Fluke, HP, Keithley, Lecroy, Rohde & Schwarz, and Tektronix.
By partnering with Alliance Test you can recover 30%-40% more on
your idle test equipment rather than selling to a dealer.
Low Phase Noise VCXO’s are now available from Bliley Technologies.
Bliley continues to strive for lower and lower noise performance
products and the V1A is another step in this endeavor. The V1A Ultra-Low
Noise series is available at customer specified frequencies between
50 MHz and 125 MHz.
Induction Furnace Designed with RF Cafe
Technician Tom D. from the
John C. Nordt company sent me an e-mail saying that he used
some of the
he found here on RF Cafe to help him design inductors for a custom
heating vacuum furnace used for melting precious metals used
in their manufacturing processes. He needed to either replace existing
equipment with very expensive commercial equipment or build one
of his own design. It was a first-pass success. Of course the real
credit goes to Tom for having the skill and inventiveness for tackling
such a challenge. The company was founded in 1872 by a German immigrant
after whom it is named. John C. Nordt still operates today as a
family business with a highly skilled engineering and production
video I have linked is a worthwhile watch if you appreciate
metals forging, casting, milling, and finishing, as well as a bit
of American history. The vault used to store gold, silver, and other
highly valuable metals is impressive. I wonder if the employees
have to pass through a metal detector going in and out of the production
area? A mere chip of lathe scrap could fund a large pizza and 2-liter
Bliley Electric & Gross Radio Ads in
two advertisements appeared in the July 1935 edition of QST.
Bliley Electric is still in business here in Erie, Pennsylvania.
They make crystals and frequency sources.
Gross Radio has been out of business for quite a while. I included
it mainly to illustrated how large radio transmitters used to be
- these things were installed in people's attics and basements back
in the day. This particular model, the CB-100, is a "100-Watt Radiophone &
C.W. Transmitter completely housed in an entirely enclosed floor
rack of ingenious design." It operated in the 1.7, 3.5, 7 and 14
MHz bands. For comparison, iCOM makes a 1 kW power amplifier
today covering those bands that measures roughly 6"(H) × 3"(W) ×
9"(D) and weighs 55 lbs.
If It's Not the Undervoltage, It's the Overvoltage
Ohms is a regular feature of Design News that presents
submissions from readers about troubleshooting challenges and how
they were solved. This story titled "If It's Not the Undervoltage,
is yet another example of why things we take for granted here in
the USA and western Europe are or were a short while ago often luxuries
in other countries. The world is fond of criticizing the West for
its past sins, but they sure are willing to receive our money and
RF Cafe Travel Bug "Europe" Now in Play
to RF Cafe visitor Richard K., of the Netherlands, a geocaching
travel bug named "Europe"
was planted in geocache location "Schöne Aussicht"
("beautiful view"), in Niedersachsen
Germany, on March 31, 2013. "Europe"
is in the form of a military dog tag.
is an immensely popular treasure hunting pastime for people equipped
with a GPS device and Internet access. There are millions of
geocaching locations all over the world. I am still seeking people
to plant RF Cafe travel bugs in Asia, the Middle East, Australia,
S. America, and Israel. I will mail the travel bug to you if you
will plant it. Please see details
AWR Exhibits, Presents, Gifts Software at
IEEE IWS 2013
will be showcasing in Booth #1617 at the
International Wireless Symposium(IWS2013)
on April 16-18 its first new release in 2013 of the AWR Design Environment™,
inclusive of Microwave Office/Analog Office circuit design software
Visual System Simulator system design software, as well as
AXIEM 3D planar electromagnetic software and
Analyst 3D finite element method EM software. The company will
also be demonstrating joint hardware/software solutions with parent
company National Instruments.
Model No. PIA-12D8G-CD-1 is a
phase locked, dielectric resonator oscillator with internal
reference having an output frequency of 12.8 GHz. This model
provides a minimum output of +13 dBm with all spurs held to
-80 dBc and harmonics held to -25 dBc. The frequency stability
is ±3 ppm with an internal reference of 100 MHz.
are invited to attend the
2013 IEEE RFIC
Symposium, which will be held in Seattle, WA from June 2-4,
2013 at the Washington State Convention Center. In conjunction with
the IEEE MTT-S International Microwave Symposium, the RFIC Symposium
opens the 2013 Microwave Week, the largest world-wide RF / Microwave
meeting of the year. The RFIC Symposium is one of the premier technical
conferences for RF design, featuring presentations, workshops, and
tutorials by recognized experts from both industry and academia
and is an exceptional venue to learn about the latest advances in
the field and to discuss key related topics.
IEEE JobSite Career Alert
month the IEEE JobSite sends out an e-mail with a few helpful hints
and stories regarding job
hunting. Even though the stock market is soaring, employment
is not, so you can probably use any help available to find a new
job - whether you are currently employed or unemployed.
AR Modular RF is Looking for a Sr. RF Test
Modular RF, designer and manufacturer of RF amplifiers, is recruiting
for the position of
Senior RF Test Technician who has significant experience in
the testing of medium to high power RF amplifiers from 100 kHz
to 6 GHz. We build RF Amplifiers ranging from single modules
with a few hundred watts power to larger rack mounted multi-kilowatt
designs. You must be a "hands on" senior technician capable
of testing RF amplifiers with minimal supervision. The position
requires that you are very familiar with RF Bench test equipment
such as RF signal generators, Network and Spectrum Analyzers, Power
meters and digital scopes and be able to fault find down to the
Please Thank otofab for Supporting RF Cafe
Chemical Etching has been a leading supplier of mission critical
thin metal parts since 1967. Custom-made precision metal parts -
chemical etching, metal stamping,
RF shielding, or
any custom part made out of metal is their specialty. Fotofab will
send you some sample parts (they make good
conversation pieces), design guide and more information regarding
their quality custom parts, short lead-times and low cost services.
Amateur Radio Quiz: Your Days Are Numbered
from the ARRL website is provided by H. Ward Silver, N0AX.
"Worse than the dreaded 'word problem,' this
April quiz is full of backward problems where I give the answer
and you pick the problem. Or something like that. You'll figure
Some Facts on Quartz Crystals
to a 2001 paper published by the National Institute of Standards
and Technology (NIST, formerly National Bureau
of Standards, NBS), "The end of the era of quartz frequency
standards began in 1949 with the development at NBS of the world’s
first atomic frequency standard based on an ammonia absorption line
at 23.87 GHz." Further, "The Bureau supported work on both
technologies for the next decade, but the rapid advances in the
accuracy of atomic frequency standards could not be matched by quartz
devices, and the work on quartz frequency standards was stopped
in 1959." This article from a 1957 edition of Popular Electronics
claims that the "master of all master-clocks" resided at the U.S.
Naval Observatory at the time - not quite accurate from what my
research indicates. Still, it is a good introduction to
crystal growth and processing for use as timing devices.
Featured Book: A Genius in the Family, by
Hiram Percy Maxim
Percy Maxim, as a lot of RF Cafe visitors already know, was a pioneer
in the realm of amateur radio. He was the progenitor of the American
Radio Relay League (ARRL).
What might not be as well known is that he was the son of
Hiram Stevens Maxim, a very successful firearms manufacturer.
Maxim Gun was the first self-powered, fully automatic machine
gun, capable of firing 600 rounds per minute. It played an important
role in European colonization in Africa. The mere sight of the gun
struck fear in the hearts of enemies. H. Percy Maxim's uncle
Hudson Maxim invented smokeless gunpowder and other revolutionary
explosives. You might say that firearms wealth funded the beginnings
of the ARRL and most of what amateur radio is today. Knowing this
now, can ardent anti-2nd-Amendment gun confiscation proponents or
anti-gun people anywhere in the world continue in the hobby in good
conscience? Wouldn't it be like buying S. Africa
Krugerrand gold coins in spite of Apartheid history, or buying
Nikes made in youth sweat shops, or cellphones made in near slave
Arena.xlsm Excel-Based Game
is pretty cool, especially if you appreciate someone using a tool
for a purpose likely never conceived of by its original creator.
You have probably used a Microsoft Excel spreadsheet at some point
in your career for business, engineering or personal calculations.
Did you know that Excel is programmable in the form of macros
(Visual Basic for Applications, aka VBA)
and via external calls from other programming languages? My RF Cascade
Workbook series relies heavily on VBA. This rudimentary game titled
is a spreadsheet created by Mr. Cary Walkin
(xlsm is the file extension for an Excel file
with embedded macros). Your objective is to pursue and slay
evil snakes, bunnies, and other garden variety
(pun intended) creatures before they
kill you. The interface is reminiscent of early
Congrats to the March 2013 Book Drawing
S., of Socorro, NM, is the winner of the March 2013 book drawing.
Ryan opted for Introduction to Infrared and Electro-Optical
Housee). Every time someone buys one of my
products(Visio Stencils, Word Symbols,
RF Cascade Workbook, etc.), his/her name is thrown into my
'electronic' hat, from which at the end of each month a name is
drawn at random. I pay the shipping cost, which if it happens to
be an overseas winner, can be more than $40.
Youth@HamRadio.Fun: New Kid in Town
Coffey, N0SSC, ARRL Youth Editor, publishes a monthly column online
young Ham radio operators. He writes about topics of interest
to fellow students like moving to a new town, attending charter
school science fairs, seeking out and joining
amateur radio clubs,
etc. If you have or know a kid that might be interested, be sure
to let him/her know about the feature.
Demystifying the PLL
RF and microwave engineers we use a lot of frequency sources that
are synchronized to reference oscillators. Doing so requires some
form of phase-locked loop circuitry. Feedback and control circuits
classes in college taught the basics that are simple enough to understand,
but unless you happen to have designed a
PLL circuit during your career
- we more often buy packaged devices or modules that someone else
designed - chances are the concept has become a bit fuzzy by now.
This brief article in EDN runs over the basics of
World's Tiniest Cellphone Recharger
this is not an April Fool's joke - that was for yesterday. This
miniature Jerry can measuring only 1.3 x 0.9 x 0.5 inches is to
your charge-challenged cellphone what its full-size gasoline-carrying
version is to your Jeep, Chang'an
OuLiWei MPV(State-owned like GM),
or whatever. The
Fuel Micro Charger,
spawn of yet another
Kickstarter project ($53k raised to date
with $20k goal), is said to be able to provide an extra 20-30
minutes of talk time to your phone by virtue of its 220 mAh
capacity. Just plug it into the micro-USB port - as long as your
phone is not made by Apple - and away you go. An iPhone version
is in the works, BTW. Get one of the first production models for
a pledge of less than $20.
William Hepburn's Worldwide Tropo Ducting
to Patricia W. for letting me know about this amazing website for
tropospheric ducting conditions and predictions. Patricia originally
wrote to me asking if I knew of any resources for
ducting information since she had a customer who suspected it
was the cause of some transmission problems. I suggested she check
with the ARRL folks but although she couldn't find any ducting info
on the ARRL.org website, she did locate William Hepburn's
Centre. It provides a plethora of data including
of VHF, UHF & microwave radio and TV signal strength and
interference. So, ultimately she ended up helping me... and you
if you ever need to know about tropospheric ducting.
Thanks Much to NuWaves for Long-Time Support
Engineering is a premier supplier of radio frequency (RF) systems,
products and engineering design services designed to customer
requirements. They are are a turnkey provider for RF and microwave
communication custom designs with full project management and design
responsibilities. Products include antennas, RF tuners, up/down
converters, LNAs, modulators, and filters.
Flying High at Zero Altitude
flight simulator software (MS Flight Sim 2002) and computer I run
it on (HP i7 notebook) are each more powerful than the software
and computer that ran the Douglas DC-8
pilot training simulator featured in this 1958 article in
Popular Electronics. Two racks of 1000+
vacuum tubes did the electronic heavy lifting while massive DC motors
did the physical cockpit heavy lifting. The computer needed to handle
as many as 40 variables at one time, including 6 differential equations
of motion. 100 servomotors, 540 amplifiers and 2,200 gears drove
the instrument panel gauges, dials, and movie projector mechanisms.
The instrument panel description conjures images of the inside of
a modern office-grade copying machine with its very dense conglomeration
of gears and axels (have you seen the inside of one of those lately?).
often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when
you cannot express it in numbers, your knowledge is of a meager
and unsatisfactory kind; it may be the beginning of knowledge, but
you have scarcely, in your thoughts, advanced to the stage of science,
whatever the matter may be." - Lord Kelvin, aka William Thompson,
in lecture on "Electrical Units of Measurement"
(3 May 1883)
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