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
in the upper left corner of every page
Z-Comm's Ultra Wideband VCO Tunes from 2.7 to 5.4 GHz
new 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 Policeman
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 told
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 Engine Light
Technologies' RF modules,
remote 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 consulting, 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, and manufacturing.
Fundamental Crystal Control for Ultra-High Frequencies
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
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
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
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 Filter
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
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
Model No. 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 350 mA.
of Passive RF Front-End Components in SoCs, by Hooman Darabi and Ahmad Mirzaei. Examining the most important
developments in highly integrated
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
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.
Microwave Office,Visual System Simulator,Analog Office,Axiem, and
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 problems with
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
crosswords 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 Cable Line
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 of Support
Angus designs and manufactures antennas, positioners, 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 Bite You
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 Plans
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 Itron's
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 on the
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 Winners
to the generosity of both Artech House and
Cambridge University Press, I am able to
offer a variety of engineering books for selection by
monthly drawing 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 Components
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 gas filler.
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 Unmanned Aerial 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,
Hand Soldering and Circuit Board Repair, by H. Ted Smith. Straightforward and easy to understand, the 6th
edition of Quality Hand Soldering and
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 in Engineering
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 to co-chair
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 Optenni 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
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 Anytime Soon
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 "NASA
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.
U.S. 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 to
Mission to Planet Earth. Not to worry,
though, at least a NASA outreach to the Muslim
world - a religious group, BTW - is in the works.
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.
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 WaveXorb line 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
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
Electrical Engineering Crossword for April 7, 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.
Please Thank Alliance Test Equipment for Their Support
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 Formulas
Technician Tom D. from the John
C. Nordt company sent me an e-mail saying that he used some of the
formulas he found here on RF Cafe to help him design
inductors for a custom induction 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
crew. The 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 soda.
Bliley Electric & Gross Radio Ads in 1935 QST
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, It's the
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 technology.
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. Geocaching 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 here.
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 and
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
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 Technician
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 component level.
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
latest quiz 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 it out!"
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
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
Sir Hiram Stevens Maxim, a very successful firearms
manufacturer. The 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 labor
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
Arena.xlsm 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 Winner!
S., of Socorro, NM, is the winner of the March 2013 book drawing. Ryan opted for Introduction to Infrared
and Electro-Optical Systems (Graciously provided by
Artech Housee). Every time someone buys
one of my software 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 directed toward
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,
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 Forecasts
to Patricia W. for letting me know about this amazing website for obtaining
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
DX Information Centre. It provides a plethora of data
including 6-day forecasts 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, subsystems,
RF 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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RF Cafe Webmaster:
Kirt Blattenberger KB3UON