Homepage - RF Cafe
Webmaster: Kirt Blattenberger | KB3UON | Sitemap | ©1996-2014
Menu below is just a small sample of what is here!
 
Custom Search
More than 10,000 searchable pages indexed.
•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

Homepage Archive April 2013

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
Homepage Archive Pages
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13
2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

Please click here for 4/21/2013 through 4/30/2013

Z-Comm's Ultra Wideband
VCO Tunes from 2.7 to 5.4 GHz

Z-Communications Intros 1200 MHz VCO for High-Speed A/D Converters - RF CafeThe 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

Dzhokhar A. Tsarnaev, a 19 - Boston Bomber at Large"With 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

Sherlock Ohms: "Car Radio Fires Up Check Engine Light" - RF CafeSherlock Ohms is a regular feature of Design News that presents submissions from readers about troubleshooting challenges and how they were solved. This story titled "Car Radio Fires Up Check Engine Light." The saga is a great example of troubleshooting skills - and a bit of good luck.

Many Thanks to Linx for
Long-Time Support

Linx TechnologiesLinx 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

Apex WirelessSince 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

Fundamental Crystal Control for Ultra-High Frequencies, April 1932, QST - RFCafeAs 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

Why, Strategic Air Communications, December 1950 Radio & Television News - RF CafeYou 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 Filter

Hittite Launches New Programmable Bandwidth Low Pass Filter - RF CafeHittite 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

PMI Intros 2.0 to 18.0 GHz Low Noise Amplifier - RF CafePMI 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.

Featured Book

Featured Book: Integration of Passive RF Front-End Components in SoCs (Cambridge University Press) - RF CafeIntegration 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 circuit parameters.

Please Thank AWR for
Their Continued Support

Applied Wave ResearchAWR, 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

Alchemy? Scientists Discover Method for Selectively Creating Elements from Fissile Mass FragmentsWell, 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

Using the Decibel, March 1955 Popular Electronics - RF CafeFor some reason even a few really good technicians and engineers have problems with 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

Crossword Puzzle, October 1957 Popular Electronics - RF CafeHere 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!

American Microwave CorporationAmerican 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

Single Layer Coil Design Chart, March 1955 Popular Electronics - RF CafeSingle 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

Pasternack Introduces New Line of Semi-Flexible Precision Cable Assemblies - RF CafePasternack 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.

Hittite Intros QFN I/Q Mixers for
X-Band & 24 GHz Applications

Hittite Intros High Performance QFN I/Q Mixers for X-Band & 24 GHz Applications - RF CafeHittite 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

Q-par AngusQ-par 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*

RF Cafe Smorgasbord - Tax Day 2013: RF Cafe's *Fair Share* - RF CafeTax 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 [2012] federal [adjusted gross] income tax rate is 18.4%..."

Sherlock Ohms: Least-Obvious
Signals Sometimes Bite You

Sherlock Ohms: "The Least-Obvious Signals Sometimes Bite You" - RF CafeSherlock 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

Therapeutic Horse Riding Mounting Platform & Ramp Plans - Airplanes and RocketsMy 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...

Notable Quote

Notable Quote: "It's very hard to find a work ethic better than that in the Upper Midwest" - RF Cafe"It's 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

Science & Engineering Crossword Puzzle for April 14, 2013 - RF CafeEvery 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

Radar: The Silent Weapon of World War 2, October 1945 - RF CafeIf 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

Planar Monolithics (PMI)Planar 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

Bliley Technologies Intros Ultra Stable Surface Mount TCXO - RF CafeBliley 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

Weekly Job Hunting Tips, 4/12/2013 - RFM CafeHere 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.

Hiring Wisdom: Top 10
   Ways to Guarantee Your
   Best People Will Quit
Top Performers Never Work
   "For" a Company
2013 Engineering Jobs
   Outlook
Resume Tips for Engineers
Sample Resume for an
   Entry-Level Electrical
   Engineer
Sample Resume for a
   Midlevel Electrical Engineer

6 New Books Added for
Selection by Monthly Winners

6 New Books Added for Selection by Monthly Winners - RF CafeThanks 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

An Experimental Station on Wheels, July 1935 QST - RF CafeThe 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

Misunderstanding of Precision - RF CafeIf 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!

3gmetalworxSince 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


The Naval Sea Systems Command Directed Energy and Electric Weapon Systems Program Office, LaWS - RF CafeNaval 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, interception.

Featured Book

Quality Hand Soldering and Circuit Board Repair - RF Cafe Featured BookQuality 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

AWR's Sherry Hess Tapped to Co-Chair IEEE MTT-S Women in Engineering Organization - RF CafeAWR 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

New Version of Optenni Lab - RF CafeOptenni 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 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 5th column.

"It's Déjà Vu All Over Again"

GE Transportation in Erie, PA, Announces 950 Layoffs (Yogi Berra photo from Wikipedia)- RF CafeThat 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

NASA Chief: USA Will Not Go Back to the Moon Anytime Soon - RF CafeMaybe 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

After Class, Working with Phase-Shift Oscillators, December 1958 Popular Electronics - RFCafeThere 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...

PMI Intros 10-Bit Digitally
Controlled Phase Shifter

PMI Intros 10-Bit Digitally Controlled Phase Shifter - RF CafeThe 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

Cross RFCross RF 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

Introducing WaveXorb - A 3Gmetalworx Solution - RF CafeIn 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 requirements.

Notable Quote

Notable Quote: "Consensus is the absence of leadership" - RF Cafe"Ah 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

W1AW Will Help YOU Become a Ham, January 1957 Popular Electronics - RF CafeW1AW, 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 7, 2013

Electrical Engineering Crossword Puzzle for April 7, 2013 - RF CafeEvery 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

Alliance Test EquipmentAlliance 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.

Bliley Technologies Intros
Ultra Low Phase Noise VCXO

Bliley Technologies Intros Ultra Low Phase Noise VCXO - RF CafeUltra 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

John C. Nordt Induction Furnace Design with Help of RF Cafe Formulas - RF CafeEngineering 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

Bliley Electric & Gross Radio Advertisements in July 1935 QST - RF CafeThese 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

Sherlock Ohms: "If It's Not the Undervoltage, It's the Overvoltage" - RF CafeSherlock 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 Overvoltage" 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 technology.

RF Cafe Travel Bug "Europe"
Now in Play

Geocache Travel Bug "Europe" - RF CafeThanks 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

AWR Exhibits, Presents, and Gifts Software at IEEE IWS 2013 - RF CafeAWR 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.

PMI Intros 12.8 GHz PLL
Dielectric Resonator Oscillator

PMI Intros 12.8 GHz Phase-Locked Dielectric Resonator Oscillator - RF CafePMI 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.

10 Highest Paid Executives
in Wireless in 2012

The 10 highest paid executives in wireless in 2012 - RF CafeFierce Wireless posted a list of the 10 highest paid executives in the wireless industry in 2012.

  Company  Compensation
1 AT&T, R. Stephenson $22,234,703
2 Qualcomm, P. Jacobs $20,730,873
3 Verizon, L. McAdam $14,049,100
4 AT&T, R. de la Vega $11,926,329
5 Sprint, D. Hesse $10,435,741
6 Motorola, D. Brown $10,325,173
7 MetroPCS, R. Linquist $7,011,752
8 Verizon, D. Mead $6,399,606
9 Nokia, S. Elop $5,550,005
10 Apple, T. Cook $4,174,992

IEEE RFIC 2013 Symposium
June 2-4, Seattle, WA

RFIC 2013 Header - RF CafeYou 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

IEEE JobSite Career Alert - RF CafeEach 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.

H-1B Visa Application Period Reignites Debate Over U.S. Need for Foreign Workers

Is There Really a Skilled-Labor Shortage?

Employers Use Sensors to Gather Data On Employee Interaction

AR Modular RF is Looking
for a Sr. RF Test Technician

AR Modular RF Looking for a Senior RF Test Technician, April 3, 2013 - RF CafeAR 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

FotofabFotofab 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

Amateur Radio Quiz: Your Days Are Numbered - RF CafeThis 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

After Class: Special Information on Radio - Some Facts on Quartz Crystals, TV, Radar, and Nucleonics, January 1957 Popular Electronics - RF CafeAccording 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

A Genius in the Family, by Hiram Percy Maxim - RF CafeHiram 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 conditions? 

Arena.xlsm Excel-Based Game

Arena.xlsm Excel-Based Game - RF CafeThis 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 DOS-based games.

Congrats to the March 2013
Book Drawing Winner!

Introduction to Infrared and Electro-Optical Systems - RF Cafe Book GiveawayRyan 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

Sterling Coffey, N0SSC, ARRL Youth Editor - RF CafeSterling 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

Demystifying the PLL - RF CafeAs 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 PLL operation.

World's Tiniest
Cellphone Recharger

World’s smallest mobile charger fits on a keyring - RF CafeNo, 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 Forecasts

William Hepburn's Worldwide Tropospheric Ducting Forecasts - RF CafeThanks 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

NuWavesNuWaves 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

Flying High at Zero Altitude, December 1958 Popular Electronics - RF CafeMy 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?).

Notable Quote

Notable Quote: "For God's sake, go down to reception and get rid of a lunatic who's down there..." - RF Cafe"I 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)

A Disruptive Web Presence

Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe
Webmaster: Kirt Blattenberger
    KB3UON

RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

RF & EE Symbols Word
RF Stencils for Visio

Product & Service Directory
Personally Selected Manufacturers
RF Cafe T-Shirts & Mugs

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
Your RF Cafe Progenitor & Webmaster
Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an
                                 engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem! (Seize the Day!)

5CCG (5th MOB): My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website