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Homepage Archive May 2015

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 "Search RF Cafe" box at the top of every page. About RF Cafe.

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$5.00 for Best Short Wave Kink

$5.00 for Best Short Wave Kink, May 1935 Short Wave Craft - RF CafeIf you need a cheap, quick lightning arrestor for your antenna or just about any type of wired system, this idea from Mr. Burgess Brownson looks like a good idea. He used an automotive spare plug. Voltage breakover points can be set by varying the spark gap distance. The old vacuum tube transmitters and receivers had a better of chance of surviving a lightning strike because the components were able to handle much more of a shock than our modern semiconductor sets with miniature, closely spaced components. Still, the spark plug setup is better than nothing, if for no other reason than to protect the shelter. it should suffice. This and many ...

More Free Whitepapers

Engineering White Papers & Books, May 2015 - RF CafeThe free whitepapers, pamphlets, books, and chapter examples listed here are a small sample of a lot of new items that are offered for FREE through TradePub. The publishers make them available to qualifying people as a promotional campaign for their full line of offerings. You might want to take a couple minutes to see what's new there. They are all free downloads ...

Mysterious Short Waves

In 1935, not much was yet known about the ionosphere. Its existence was first theorized in 1902 by Arthur Kennelly and Oliver Heaviside, and Edward Appleton proved its presence in 1924 by conducting a series of broadcast experiments, but no direct measurements were possible until rocket-borne instruments could be launched. An Aerobee-Hi sounding rocket was launched in 1956 as part of the International Geophysical Year (IGY) project that made the first actual detection of ionized particles in what is now referred to as the D-layer. It is therefore forgivable that Hugo Gernsback, normally spot-on in his theories and postulations regarding RF propagation, incorrectly suggested in this editorial that based on observed time ...

More FCC Bureaucratic Strong-Arming

More FCC Bureaucratic Strong-Arming - RF CafeJust about a year ago I posted a report on the FCC punishing an amateur radio operator (Ham) for having an on-air conversation with another party who failed to identify himself per Part 97 requirements. Per FCC regulations, every control operator in the Amateur Radio Service (with few exceptions) is required to broadcast a station identification (call sign) at least once every ten minutes during periods of communication. The named operator properly identified himself, but was prosecuted for failing to terminate an exchange with someone else who did not comply. This legal action was executed by the same government which belittles honest citizens who object to its policies of ignoring illegal aliens crossing our ...

More Cardboard Slide Rule Calculators

Miteq: Mixer Spur Analyzer Calculator - RF CafeHP: Reflectometer & Mismatch Error Limits Calculator - RF CafeThanks to Joe Cahak, there are now 11 new cardboard calculators & slide rules added to the RF Cafe museum. Rare is the RF engineer or technician who has been in the business more than 20 years that has not used HP's classic Reflectometer & Mismatch Calculator slide rule. Most 'millennials' might not even associate Hewlett Packard with test equipment unless they happen to work somewhere with a stock of vintage gear. They have phone apps for this type of work. A Miteq rotary Mixer Spur Analyzer is included, as are 9 others, some with which you probably are not familiar. Old-Guy Admission: I once carried these calculators in my shirt pocket right behind my plastic pocket protector ...

Bell Telephone Advertisement

Bell Telephone Ad, June 1946 Radio News - RF CafeRemember when you could hold a telephone conversation without having to allow a moment of time at the end of a sentence before responding in order to keep from 'stepping on' the person on the other end? It used to be only overseas phone calls or maybe communicating to astronauts on the moon suffered such inconveniences, but talking to someone across town was like having a face-to-face discussion. More often than not - or so at least it seems - there is a noticeable delay between the time someone actually stops talking on the transmitter end and the time the audio stops at the receiver end. People who have ...

Electronic Applications of the Smith Chart

Electronic Applications of the Smith Chart - RF CafeOne of the few aspects of electronics that has not changed since the early days of the craft is impedance matching and, in particular, use of the Smith Chart. Many an engineer, technician, and hobbyist has been intimidated by the chart's appearance; however, after using the Smith Chart a few times for impedance and/or admittance matching, quickly develops the knack of applying it. If you have an affinity for mathematics and are comfortable with complex numbers, all the arcs and circles makes perfect sense once the simple equations governing its construction are presented. As with so many other things, you wonder how anyone ever thought to do such a thing, and at the same time wonder why it took so long for someone to think of it. Gary Steinhour (KF6U), who recently ...

Electronics-Themed Comics

Electronics-Themed Comics, October 1963 Electronics World - RF CafeIt's always hard getting back into the swing of the workaday routine after a long holiday weekend. Now that you've finished trading stories with workmates about what you did - or did not - do, take one last moment to lift your spirits by looking at these electronics-themed comics from vintage issues of Electronics World magazine. I particularly like the step switches. BTW, these comics make good fodder for opening your technical presentations ...

Notable Tech Quote

James Michener Interview Photo (achievement.org photo) - RF Cafe"A scientist studies what is, an engineer studies what never was." - James A. Michener, historical fiction author


Is Amateur Radio Still a Gateway to EE?

Is Amateur Radio Still a Gateway to Electrical Engineering? (Dan Romanchik) - RF CafeMany thanks to author and amateur radio operator Dan Romanchik (KB6NU) who sent this article for posting here on RF Cafe. A lot of electrical engineers and hobbyists are familiar with Mr. Romanchik from his stint as Senior Technical Editor for Test&Measurement World magazine (now part of EDN), and by his popular books on preparing for taking and passing Amateur Radio exams- including the newly released "No-Nonsense General Class License Study Guide." Contained within are Dan's observations regarding how Amateur Radio seems to be making a comeback in many realms including colleges, the popularity of radio displays in museums, and a rising number of 'hackers/makers' who are exploring the ...

U.S.A. Calling

U.S.A. Calling, January 1942 QST - RF CafeToday is Memorial Day in America. When America was drawn into World War II after the attack on Pearl Harbor on December 7, 1941, the country snapped into action and our citizens were ready, willing, and able to help. One big immediate need was knowledgeable electronics technicians and engineers, particularly people with experience in radio communications. Amateur radio operators were the natural reserve source for just that need. The FCC shut down Ham radio transmissions in January 1942 ostensibly for security reasons, but some suspect the reason was at least partly to motivate Hams to enter the armed services or work at government research laboratories. Still feeling ...

RF Cable Assembly Designer by Pasternack

Pasternack-New-Cable-Designer-5-22-2015.htm" > RF Cable Assembly Designer Unveiled by Pasternack - RF CafePasternack Enterprises has just released their newest engineering resource called the Cable Assembly Designer which allows the user to design and customize RF cable assemblies with an easy-to-use online web application at Pasternack.com. Pasternack's new custom cable designer enables engineers and buyers to create customized RF cable assemblies that meet their specifications from any combination of compatible connectors and cables offered by the company. Over 250,000 possible combinations Pasternack-New-Cable-Designer-5-22-2015.htm" ...

Sound Broadcasting from Airplanes

Sound Broadcasting from Airplanes, September 1947 Radio News - RF CafeUntil maybe 20 to 30 years ago, there was still a certain amount of awe associated with new applications of technology. It seems anymore people are so accustomed to new and amazing things - usually at affordable prices - that the wonder is gone. Advancements are expected. The world is moving so fast that it is difficult to absorb and fully appreciate all the work being done. In 1947, both airplanes and electronics were still relatively new to a lot of people, especially in more rural areas, so a whiz-bang scheme like broadcasting messages from an airplane was ...

MECA Announces RF Parts On Demand (RFPOD)

MECA-RF-Parts-On-Demand-5-21-2015.htm" >MECA Announces RF Parts On Demand (RFPOD)MECA Electronics announces our expedited online service center, the source for RF Parts on Demand (RFPOD) when you need them. RFPOD offers an expedited online service that process your order and has it available for pick up at will call or shipment within 2 hours from order placement to pick up time! Will Call pick up hours are 9:00 AM to 5 PM (ET) - earlier hours are available by calling customer service in advance at (973) 625-0661. Let us help solve your component problem, we are here when you need us, orders are accepted 24 hours a day, 7 days a week and shipments are made same or next business day MECA-RF-Parts-On-Demand-5-21-2015.htm" ...

Money in Radio Gadgets

Money in Radio Gadgets, February 1933 Radio-Craft - RF CafeSubstitute "cellphone" for "radio" in this title and editorial by Hugo Gernsback in 1933 and it would fit right in with today's market of wondrous gadgetry. Prescient as always, Mr. Gernsback describes, among other things, what we now refer to as energy harnessing to power ancillary devices and props. He also recommends a scheme for causing 'dancing dolls' on the surface of a table vibrated and mobilized by the sonic waves of a large speaker - a lot like the way years later vibrating football games were made (remember them?) where the men danced randomly ...

Nokomis Needs Engineers & Scientists

Nokomis Is Seeking Outstanding PhD and MS Level Electrical Engineers, Physicists and Computer Scientists - RF CafeThis is a good week for engineer job openings. Nokomis is seeking outstanding PhD and MS level electrical engineers, physicists and computer scientists position will support design and enhancement of next-generation RF/microwave devices. 3-10 years' experience is required depending on the position. Military background is a plus. Experience should include RF/microwave design and/or measurement with a focus on RF sensor systems and signal analysis. Experience with receivers, transmitters, and transceivers is a plus. Test and measurement experience as well as filter design ...

Acoustics Anagram

Acoustics Anagram, October 1961 Electronics World - RF CafeIsn't an anagram a word game where letters of one word are rearranged to spell another word or series of words? For instance, an anagram for 'microwave' is 'warm voice,' one for ''resistance" is "ancestries," and for "vector" is "covert." If so, then this puzzle is misnamed; it is really a crossword puzzle. Maybe back in 1961 the word anagram included this type of puzzle. Regardless of the naming error, I did learn a new word: "inertance," which means "the effect of inertia in an acoustic system, an impeding of the transmission of sound through ...

R&S Phase Noise Analyzer and VCO Tester

Rohde-Schwarz-FSWP-Phase-Noise-Analyzer-VCO-Tester-5-19-2015.htm" > Rohde & Schwarz Presents the Ultrasensitive R&S FSWP Phase Noise Analyzer and VCO Tester - RF CafeThe new phase noise analyzer and VCO tester from Rohde & Schwarz enables ultrasensitive and ultra-fast phase noise measurements. The R&S FSWP also allows users to very easily measure pulsed sources and residual phase noise of RF components. Plus the instrument can be upgraded to a signal and spectrum analyzer. With the new R&S FSWP phase noise tester, users can measure the spectral purity of signal sources such as generators, synthesizers and VCOs more quickly than with any Rohde-Schwarz-FSWP-Phase-Noise-Analyzer-VCO-Tester-5-19-2015.htm" ...

NuWaves Needs RF Engineers

NuWaves Engineering Seeks an Engineering Manager - RF CafeNuWaves Engineering, a premier supplier of RF systems, RF products, and engineering design services, is actively seeking talented and highly motivated RF Design Engineers with 4 plus years of experience in RF system and/or circuit design to support engineering development. NuWaves is a fast growing RF Design Engineering firm located in Middletown Ohio – North of Cincinnati and South of Dayton. Individuals must have knowledge of RF systems and circuit design. Experience with PLLs, LNAs, PAs, demodulators, modulators and other communication circuitry is essential ...

No-Nonsense General Class License Study Guide

No-Nonsense General Class License Study Guide - RF CafeDan Romanchik (KB6NU), author and instructor on all things Ham radio, has just released his latest Amateur Radio exam book titled "No-Nonsense General Class License Study Guide: (for tests give between July 2015 and June 2019). The new question pool takes effect on July 1st of this year and lasts for four years. It is available in both paperback and Kindle formats. Hopefully, Dan (read his blog) has plans to release a new version for his Amateur Extra study guide for the new question pool in 2016, for which I'll be studying. See the formal Dan-Romanchik-Updated-Study-Guide-Paperback-E-Book-5-19-2015.htm" >press release.

Lake Chevrolet Business Card in 1934 Radio-Craft

Lake Chevrolet Business Card Found in 1934 Radio-Craft  - RF CafeWhilst perusing the June 1934 edition of Radio-Craft magazine, I found betwixt the pages this business card from the Lake Chevrolet Company, of Devils Lake, North Dakota. As you can tell by the old panel truck on it, the year it was printed was probably sometime around 1934. While this business card does not have the value of a 1900s era blue chip stock certificate I keep hoping to find, it does have historic and nostalgic value - at least to me as an appreciator of the people and institutions that built America. The handwriting on the back of the card says, "Delivery 577. Cab box chassey[sic]," and "Let me know at least 3 weeks ahead." Although you cannot tell ...

NuWaves Seeking an Engineering Manager

NuWaves Engineering Seeks an Engineering Manager - RF CafeNuWaves Engineering, a premier supplier of RF systems, RF products, and engineering design services, is actively seeking talented and highly motivated Engineering Manager. Reporting to the CTO, the Engineering Manager directs the implementation of various strategic and tactical operations by performing the following duties either personally or through direct reports. Essential functions include: • Write and present proposals, reports and related findings • Participate in development and deployment of NuWaves' mission and business strategies • Perform RF Design • Responsible for leading and supervising design engineers as they ...

NuWaves Wins NASA SBIR Phase II Contract for C-Band PA

nuwaves-c-band-amplifier-nasa-sbir-5-19-2015.htm" > NuWaves Wins NASA SBIR Phase II Contract for C-Band PA Development and Prototyping - RF CafeNuWaves Engineering, an international RF and microwave solutions provider, announced today that the company has been awarded a Phase II Small Business Innovation Research (SBIR) contract from the National Aeronautics and Space Administration (NASA) to develop and prototype a miniature linear and high-efficiency C-band power amplifier to provide communication range extension for a variety of NASA missions and applications, including Unmanned Aircraft Systems (UAS) integration into the National Airspace System (NAS). Under the terms of the contract, NuWaves will, nuwaves-c-band-amplifier-nasa-sbir-5-19-2015.htm" ...

A Passive RF Limiter

A Passive RF Limiter, December 1966 QST Article - RF CafeThis passive RF limiter is a simple combination of cascaded "T" type resistive attenuators that are switched in and out of the circuit based on the power level in the line. The design takes a bit of thinking due to needing to retain a reasonable impedance match at the input and output throughout various stages' conduction states. Arriving at an optimal value for resistors would require a circuit simulator with a mathematically based optimizer, but, especially for amateur radio work, close is good enough. That is not to say Hams are a bunch of slackers - they're not - it's just that component and software resources are not as readily available (aka 'prohibitively expensive') for doing the analysis and testing. In 1966 when ...

Copper Mountain Debuts New High-Performance VNAs

Copper-Mountain-Technologies-High-Performance-VNAs-5-19-2015.htm" > Copper Mountain Technologies (CMT) introduced a new series of high-performance vector network analyzers (VNAs) designed to efficiently handle advanced test applications at the 2015 International Microwave Symposium (IMS) in Phoenix on May 17-22. The Cobalt series, which presently features the C1220 and C1209 models, offers an unmatched price-performance combination for S-parameter measurement between 100 kHz and 20 GHz. To achieve high performance and an affordable cost, the design and production of Cobalt VNAs incorporates several Copper-Mountain-Technologies-High-Performance-VNAs-5-19-2015.htm" ...

Dr. Peter Venkman Quote on Einstein

Dr. Peter Venkman: Ghostbusers(tm) - RF Cafe"You're always so concerned about your reputation. Einstein did his best stuff when he was working as a patent clerk!" - Dr. Peter Venkman, Ghostbusters

Sivers IMA Adds East Coast Microwave as Distributor

Sivers-IMA-East-Coast-Microwave-Distributor-5-18-2015.htm" > Sivers IMA Recruits East Coast Microwave as New Distributor for the North American Market - RF CafeSivers IMA, a leading manufacturer of millimeter wave products and Boston-based East Coast Microwave (ECM), today announced that they have signed a reseller and distributor agreement for the US and Canadian markets. ECM will represent the whole Sivers IMA product range including Converters and Customized Transceivers, Radar Sensors and Signal Sources such as VCOs and synthesizers. “The agreement with ECM is an important part of our expansion strategy. The North American market naturally holds a large potential for our products and we strongly believe that ECM is the right local partner for us to meet the interest we see”, says Robert Ekström CEO of Sivers-IMA-East-Coast-Microwave-Distributor-5-18-2015.htm" ...

Mechanical Bandpass Filters for I.F. Ranges

Mechanical Bandpass Filters for I.F. Ranges, February 1953 QST - RF CafeMagnetostriction is a term not seen very often these days. It describes the physical shape change that takes place in certain ferrous materials when subject to a magnetic field, and is responsible for most of the familiar 'hum' that comes from transformers. The effect is used in mechanical filters as transducers between the electronic circuit and the mechanically resonant disks that define filter bandpass characteristics. Elemental cobalt exhibits the highest room temperature magnetostriction (units are 'microstrains'). Nickel, with about half the value as cobalt, is cheaper and more abundant and is therefor more commonly used in modern magnetorestrictive transducers. Way back in the 1980s while ...

2015 College Majors with the Highest Starting Salaries

2015 College Majors with the Highest Starting Salaries: Forbes - RF CafeForbes just published its newest list showing which college majors currently enjoy the highest starting salaries. Engineering and architecture top the list at $50k US, while computers and mathematics follow closely. Next comes health fields and then business. The physical sciences fare worse than social sciences, which I find disturbing. For comparison, workers with only a high school education average $22k US. What is not mentioned, but probably implied, is whether pay for those with only a high school diploma is for right out of school or four years later when the college graduate would begin his/her career. That might be a more fair ...

Career Advice Articles

Engineering Career and Job Hunting Advice for May 18, 2015 - RF Cafe"How to Meet Amazing People Without Sleazy Networking" - now there's a catchy article title for you. It is one of the career advice offerings I found in my search for useful (mostly) items for this go-round. Not being a 'networker,' probably ultimately to my disadvantage, I am not fluent or knowledgeable in the art. However, a lot of engineers' livelihoods are significantly dependent on well-honed ...

- The 50 Happiest Companies in America for 2015

- 6 of the Best Tech Meetups in the U.S.

- How to Meet Amazing People Without Sleazy Networking

- Storytelling 101: How to Inspire, Influence and Get Results (interesting approach)

More Vintage Radio Service Data Sheets for the Archive

Hetro Air-Ace Series M, 9-Tube 4-Band Superhet, May 1936 Radio-Craft - RF CafePlease bear with me again as I post these six radio service data sheets for the benefit of hobbyists and archivists who might be searching for such information either in a effort to restore a radio to working condition, or to collect archival information. Putting links on the homepage helps get them registered fast in search engines. Hetro Air-Ace Series M, 9-Tube 4-Band Superhet, Crosley Model 1155, 11-Tube 4-Band Superhet, Canadian Westinghouse Model 175, 7-Tube Dual-Range Superhet Radio Service Data Sheet, Arvin Model 35, 8-Tube Car-Radio Receiver, Philco Models 39 and 39A, 6-Tube Dual-Range Battery Superhet, Philco-Packard Deluxe, 7-Tube Superhet Car Radio

everythingRF Providing IMS 2015 Coverage

everythingRF-Providing-IMS-2015-Coverage-5-18-2015.htm" >everythingRF will be covering the everythingRF-Providing-IMS-2015-Coverage-5-18-2015.htm" >IMS 2015 in Phoenix, Arizona. A link to the live coverage can be found here. This is a non-bias coverage unlike most of the other journals where they only publish what their sponsors are showcasing. This page will be updated as and when new products and announcements are made at the event. Visit www.everythingRF.com to learn more everythingRF-Providing-IMS-2015-Coverage-5-18-2015.htm" ...

Raytheon Bonded Electronic Technician Ad

Raytheon Bonded Electronic Technician Ad, January 1946 Radio News - RF CafeThere was a time when having a career in any field of electricity or electronics work was an enviable mark of a person's technical prowess that conveyed a degree of respect. The whole controlling of electrons thing boggled the minds of most people, whether it meant wiring homes and buildings for lights, receptacles, and motors, or designing 'all wave' radio sets for listening to the evening broadcast of "The Lone Ranger." Today, with nearly everyone alive having grown up with such conveniences, the 'wow factor' is pretty much gone, except maybe with those of us who still chose to engage. If an electronics appliance or device stops working nowadays, it is discarded rather than repaired. This 2-page advertisement ...

Electronics Themed Comics, Oct 1945 & Apr 1946 Radio News

Electronics Themed Comics, October 1945 & April 1946 Radio News - RF CafeHave you had a rough week? If so - and even if not - take a few minutes to get a laugh from these electronics-themed comics from the pages of vintage Radio News magazines. Beginning sometime in the late 1930s and early 1940s, single-panel topical comics began appearing frequently in many hobby and even professional magazines. Sure, comics showed up in magazine before that time, but they generally did not necessarily have to do with the main subject of the publication. The Saturday Evening Post, for example, had many single-panel comics, but they were on any random theme. The Saturday Evening Post, for example, had many single-panel comics, but they were on any random theme. I can't go without commenting on the April 1946 comic since it reminds me of a situation ...

R.F. Chokes at U.H.F.

R.F. Chokes at U.H.F., January 1946 Radio News - RF CafeAs radio frequencies moved up into the UHF realm of 30 MHz (through 3 GHz), designers noticed that the old methods and equations for winding inductors (aka coils and chokes) no longer performed as predicted. The culprit was stray capacitance created by the wire itself and the insulation between windings. To some extent, the length of leads running from the inductor windings to connection points (terminal strips and lugs at first and then later printed circuit boards) generated enough extra inductance to add noticeably to total inductance. New methods were developed to help mitigate the effects of these stray (aka parasitic) reactances. Much new knowledge in this area was gained through the war efforts with many radar ...

Congrats to Joe Cahak for Making the Cover of HFE!

Joe Cahak's "Pondering on Power Measurements - RF CafeLong-time RF Cafe visitor and contributor Joe Cahak's article entitled "Pondering on Power Measurements" (it begins on page 22) just made the cover of High Frequency Electronics magazine's May edition (IMS2105 preview). Joe's expertise lies in many areas of electrical engineering, with an emphasis on RF. He has authored many articles, such as "Measurements with Scattering Parameters" and "Searching for the Q," appearing here and elsewhere. Joe's other interests include amateur astronomy, cycling, hiking, and mineral / rock collecting. His Sunshine Design Engineering Services company is located in Ramona, California.

More Experts in Demand as Bootstrapping is Banned

More Experts in Demand as Back-Door Bootstrapping is Banned - RF CafeThe good folks at IMS ExpertServices have published an interesting short article highlighting the increasingly difficult technical issues being brought before courts in intellectual property (IP) cases. Attorney Ryan Thompson, who holds degrees in both law and journalism, tells here about a recent court ruling that places severe restrictions on the ability of an expert witness to cite and admit as evidence material based on the work of another non-testifying expert witness. Known in the legal realm as 'bootstrapping,' the practice has greatly burdened efforts required to rebut massive volumes of opinions admitted as evidence based solely on the endorsement of an expert who is physically present and testifying in the courtroom. This strategy, used extensively in patent cases, is especially ...

Welcome James Stanton to the Radar Shop Hall of Fame!

James Staton added to USAF Radar Shop - RF CafePlease welcome James Stanton as the newest USAF radar tech to be inducted into the Radar Shop Hall of Fame! James served in the 3rd Combat Communications Group (3CCG) at Tinker AFB, Oklahoma. He's an 'old school' guy with 'new school' technical expertise, having served 8 years as a cadet in Civil Air Patrol, 9 years in the USAF as an Air Traffic Control Radar Technician, and earning an AAS degree in Electronic / Electrical Engineering. James now owns and operates James' TV and Audio Repair shop in Milton, DE, servicing cellphones, computer monitors, wide screen TVs, speakers, appliances, and more.

If You Are Going to Buy Through Amazon.com Anyway ... 

Amazon Prime Associate - RF CafePlease support RF Cafe through Amazon.com purchases! By clicking this link or logo when initiating an Amazon shopping spree, RF Cafe (a one-man operation - me) earns a small commission and it does NOT affect the price you pay in any way. Most items qualify for free shipping when you spend more than $35. Melanie and I always check with Amazon for a price comparison prior to buying anything we don't need immediately or cannot be bought through the mail (like groceries). Your support is definitely needed and appreciated. Thanks!

NI AWR Design Environment V12 Pre-Release Now Available

NI-AWR-Design-Environment-V12-Pre-Release-5-12-2015.htm" > NI AWR Design Environment V12 Pre-Release Now Available - RF CafeNI (formerly AWR Corporation), announces that NI AWR Design Environment™ V12 - the first major software release in 2015 - is now available as a pre-release to select customers, partners and evaluators. Previewing for the first time at International Microwave Symposium 2015 (IMS2015) in NI booth #2431, this latest release boasts new load-pull and antenna- and radar-specific features, as well as ease-of-use improvements, speed enhancements and third-party integration flows.

RF Engineer III Needed by BOSH Global Services

BOSH Global Services Needs an Experienced RF Engineer - RF CafeBOSH Global Services has an opening for an experienced RF engineer who would like to work in the small unmanned aerial systems (sUAS) realm. I know there are a lot of engineers who fly radio controlled model airplanes and the current crop of drone platforms. This would be an excellent opportunity to get paid while enjoying your hobby passion. If you happen to be an Amateur radio type as well, then it's a twofer.. Read about the qualification and duties in this RF Engineer III job listing.

Free Engineering & Science Magazine Subscriptions

Engineering & Science Magazine Subscriptions, May 2015 - RF CafeMany of these magazines have websites that I visit on a daily basis in search of up-to-the-minute industry headlines. Free subscriptions are offered to qualified applicants. 'Qualified' usually means that you are currently employed in a field related to the primary theme of the magazine, and often you also need to be a decision maker for buying products represented within the pages. Technical magazine coffers, like mine here at RF Cafe, get filled by advertisers and therefore we/I need the public to support those companies by purchasing their products and/or services. If you believe you meet the qualification(s) and can use a subscription ...

Oscilloscope Traces: Squarewaves

Oscilloscope Traces, November 1957 Popular Electronics - RF CafeThis is one of a multi-part series of articles that appeared in Popular Electronics magazine on using an o-scope to analyze signal waveforms. An introduction to square waves and how to accurately measure them is covered here. Frequency-compensating the o-scope probe is always an important step prior to sampling just about any waveform other than a pure sinewave, because per Fourier series analysis, every periodic waveform can be defined by a series of sinewave and various frequencies, phases, and amplitudes. The author demonstrates with a square wave being composed of the fundamental frequency and its odd harmonics. I remember being amazed to learn whilst in engineering school that ...

Empower RF Systems Patent Approval

Empower-RF-Systems-Patent-Approval-5-10-2015.htm" >Empower RF Systems Patent Approval - RF CafeUnited States Patent 9,007,125 B2, recently awarded to Empower RF Systems, validates the uniqueness of the hardware architecture in use on Empower's high power, next generation amplifiers. The ability to deliver 1 kW CW broadband power in an air cooled, 5U chassis requires innovation and engineering breakthroughs that are described and protected in this patent award. "We are pleased to receive this recognition and patent protection for our next generation amplifiers," said Jon Jacocks, CEO. "The hard work and creativity of our design teams, leveraging this architecture for standard products and customer configurations, continues to Empower-RF-Systems-Patent-Approval-5-10-2015.htm" >..."

Super-Power UHF Tubes

Super Power U.H.F. Tubes, October 1961 Electronics World - RF CafeJust as modern high power semiconductor amplifiers are composed of cascoded (connected in parallel) lower power amplifier units, so too a super-high-power vacuum tubes. In the case of tubes, a requisite number of triodes (typically) are arranged around the perimeter of the tube enclosure with the inputs and output connected to power dividers and combiners, respectively. Vacuum tubes are still used in high power applications, although it is rare that you will find them with glass enclosures; most are metal and/or ceramic. Over-the-air radio and television broadcasting stations are major users. Richardson Electronics is a major distributor for ...

3 New Cardboard Slide Rules Added to the RF Cafe Museum

Control Components Cardboard Slide Rule Museum - RF CafeMany thanks to website visitor Joe Birsa (N3TTE) for donating three vintage cardboard slide rule calculators to the RF Cafe Slide Rule Museum. Reflecting off of Joe's history in the nuclear power industry, one is Radiation Measurement Calculator from Ohmart, another is a Valve Sizing Calculator from Control Components, and the other is Air-Gas Orifice Flow Calculator from Daniel Industries. Any similar items you might care to donate would be very welcome and appreciated.

Notable Tech Quote: Scott Adams

Scott Adams Notable Quote, May 12, 2015 - RF Cafe"Scientists will eventually stop flailing around with solar power and focus their efforts on harnessing the only truly unlimited source of energy on the planet: stupidity. I predict that in the future, scientists will learn how to convert stupidity into clean fuel." - Scott Adams, creator of Dilbert

Anatech Electronics Intros Coupler, Combiner, Circulator

anatech-product-update-5-12-2015.htm" > Anatech Electronics Product Update for May 12, 2015 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Anatech has released three new designs: a 2 to 18 GHz connectorized directional coupler, a 2027-2108 MHz & 2452-2484 MHz connectorized band combiner filter, and a 80-225 MHz connectorized circulator. All can be ordered directly through their AMCrf web store.

Hams Go Video

Hams Go Video, June 1959 Popular Electronics - RF CafeIronically, an RF Cafe visitor just within the last couple days wrote about possibly getting his Amateur radio license in order to permit live broadcasting of his kite-borne video camera system (known as "Kite Aerial Video" [KAV]), or Kite Aerial Photography [KAP]). Slow scan television SSTV has long been a popular facet of Ham radio since prior to broadband Internet connections, it was the only practical method available. Older equipment was large, heavy, power hungry, and relatively expensive, but today you can buy a much improved camera for a few bucks that transmits real-time via an unlicensed 2.4 GHz wireless link. That data stream can be recorded for later use of streamed real-time to the Internet. As with so many other things, easy availability take some of the challenge out of it, but the world benefits from ...

RF & Microwave Engineering Articles for Mid-May

RF & Microwave Engineering Article for May 11, 2015 - RF CafeBelieve it or not, the International Microwave Symposium (IMS2015) is almost upon us; it is next week. Having been to a few of the shows, I can tell you if you have never been to one that there is a lot to take in and it is easy to miss something you would liked to have seen if you don't do a little research ahead of time. Tom Perkins wrote an article for High Frequency Electronics magazine titled "Maximizing Your Symposium Experience" (page 32) that provides a bit of guidance in that regard. There are a lot of other great articles out now. Is it my imagination, or are there an inordinate number of guys ...

Side-Looking Radar Imagery

Radar Imagery, August 1965 Electronics World - RF CafeSide-looking airborne radar started out using a narrow beam formed by reflectors, like traditional radars, as opposed to the synthetic aperture type most often (maybe even exclusively) used today. Both types of side-looking radars rely primarily on the physical movement of the airborne platform for effective azimuthal scanning rather than steering the beam either mechanically or electronically. Modern computer-controlled synthetic radar beams can be segmented and directed off-axis for detected areas of interest as required, but the early systems simply gathered radar return data and presented it real-time, with some level of analog processing, to operators ...

Radio-Operated Airplanes

Radio Operated Airplane, January 1946 Radio News - RF CafeWhen I first saw this article from a 1946 edition of Radio News, I did a double-take on the author's name, thinking it was written by long-time model aviation author and magazine editor William 'Bill" Winter. It was actually done by a fellow named Winters, not Winter. An enthusiastic radio control (R/C) evangelist in his day, Bill Winter wrote many pieces for electronics magazines such as Popular Electronics. As I have noted in the past, hobbyists in the electronics realm, as well as in the fields of aircraft and rocket design, contribute mightily to the state of the art. Such is also the case in many other arts and sciences. Here we have a report of some of the earliest radio controlled flying 'drones,' as we call them today. They are a far cry from the ...

Magnetic Ceramics: Ferrites Magnetic Materials for RF

Magnetic Ceramics: Ferrites, February 1953 QST - RF CafeMagnetic ceramics have been with us for a long time - probably forever as far as most people that use them these days are concerned. When this article was published in 1953, ferrites for use at RF frequencies were a new, breakthrough phenomenon. Take a look at inductors used in vintage radio equipment and you will find either air or solid iron as the permeable filler elements in most instances. Whereas iron might have a permeability of 100-150, the new magnetic ceramics exhibited permeabilities up to 4,000 at 1 MHz, and even higher for lower frequencies. Modern alloys and compounds provide permeabilities of more than 50,000 for special applications. Such high values allow physical size and weight of inductors and transformers ...

Narda Safety Test Solutions Wide-Area Data Measurement

Narda-Safety-Test-Solutions-Wide-Area-Data-Collection-5-6-2015.htm" > New Area Monitors from Narda Safety Test Solutions Simplify Wide-Area Measurement Data Collection - RF CafeNew on the market from Narda Safety Test Solutions is the Narda-Safety-Test-Solutions-Wide-Area-Data-Collection-5-6-2015.htm" >AMB-8059, a wideband Area Monitor that monitors electromagnetic fields up to 7 GHz in conformance with the ITU-T Recommendation K.83. The data can be accessed via Ethernet or GSM/UMTS. The “EMF Observatory” software integrates several Area Monitors into a wide area coverage monitoring system. The new type AMB-8059 Area Monitors monitor electromagnetic fields in accordance with the ITU-T Recommendation K.83: Monitoring of electromagnetic field levels. Depending on the probes used, they capture electric field strengths in the frequency range 100 kHz to Narda-Safety-Test-Solutions-Wide-Area-Data-Collection-5-6-2015.htm" ...

The Clapp Oscillator - and How!

The Clapp Oscillator - and How!, February 1953 QST - RF CafeJames ilton Clapp in 1948 first published details on an oscillator that used positive feedback obtained from an LC (capacitive & inductive) voltage divider to initiate and sustain oscillations. Thus was born the now familiar Clapp oscillator. It had an advantage over both the Colpitts and Hartley oscillators because the feedback, not being dependent on a simple capacitive or inductive voltage division, respectively, made it more reliable as a variable frequency oscillator (VFO). This article does a nice job of explaining the operation of the Clapp oscillator. Just as the Colpitts and Hartley oscillators handily provide an easy mnemonic for being based ...

Please Welcome Empower RF Systems as a New Advertiser

Empower RF Systems - RF CafeMany thanks to Empower RF Systems for helping to deliver RF Cafe to the world! Founded in 1999, Empower RF Systems is a global leader in power amplifier solutions that are critical to defense, commercial, and industrial market applications. With our origins in the design of broadband and band-specific solid state power amplifiers, Empower continues to advance the science of RF power amplification to produce rugged, power efficient, and cost-effective solutions in the industry. Empower RF Systems will be in Booth #3226 at the IMS 2015 how in Phoenix. See you there!

Crystals Go to War

Many thanks to Kevin, of Roanoke, VA, for sending me a link to this documentary video covering the entire production chain for radio crystals as filmed by Reeves Sound Laboratory, in New York, NY. It was produced during World War II so the methods used are not anywhere near what is common today. What is the same, fundamentally, is the ingenuity and hard work that goes into developing a new technology, and particularly the effort needed to move to high volume production. As with most of these vintage factory films, a few aspects of normal practices of the era are immediately apparent. First is the near utter lack of personal safety devices on machinery and accessories for workers. Fingers run perilously close to diamond-impregnated crystal dicing blades, unprotected hands and arms are submersed in oils and cleaning solutions, no ear protectors ...

Scientific Observation Not Always Reality

Scientific Observation Not Always Representative of Reality - RF CafeTo look at this drawing of the path Venus takes across the sky, the casual observer might never expect that it actually follows a simple elliptical orbital progression around the sun. No wonder the word 'planet,' meaning 'wanderer,' was assigned to the bright, rapidly moving night sky objects like Mercury, Venus, Mars, Jupiter, and Saturn. In fact, until the middle of the 16th century when Nicolaus Copernicus promoted his heliocentric model of the solar system, a vast majority of 'experts,' 'professionals,' 'learned scholars,' etc., held fast to a belief that Earth was the center of the universe and everything moved relative to it. Sophisticated mathematical and mechanical models were created by some of the smartest minds of the day to explain the circuitous movement of the planets. Indeed, and to their great credit, observed phenomena ...

NuWaves Linear Bidirectional S-Band  OFDM Amplifiers

NuWaves-bidirectional-s-band-linear-ofdm-amplifiers-5-5-2015.htm" > NuWaves Engineering Introduces Linear Bidirectional S-Band Radio Frequency Amplifier Module for OFDM Transceivers - RF CafeNuWaves Engineering, an international RF and microwave solutions provider, today announced a new linear bidirectional amplifier for OFDM radios at the Association for Unmanned Vehicle Systems International Unmanned Systems 2015 Trade Show. The NuPower Xtender™ 12E06A model is a broadband, small, lightweight and cost-effective solution for high-performance S-band OFDM transceivers with Mobile Ad hoc Networking (MANET) and/or Multiple-Input and Multiple-Output (MIMO) technology NuWaves-bidirectional-s-band-linear-ofdm-amplifiers-5-5-2015.htm" ...

Zeppelin Radio Equipment: Pre-Hindenburg Disaster

Zeppelin Radio Equipment, July 1936 Radio-Craft - RF CafeToday is the 78th anniversary of the Hindenburg disaster at the Naval Air Station in Lakehurst, New Jersey. It is the RF Cafe logo theme for today (see upper left page corner). Ironically, last night while looking through the July 1936 edition of Radio-Craft magazine, I saw this news article reporting on preparations being made in the onboard radio and direction finding equipment for Hindenburg's maiden voyage from its home base in Frankfurt, Germany to North America. No one at the time of this article suspected such a terrible fate was looming les than a year later. Theories abound regarding the cause of the fatal fire, but there is no doubt that a combination of highly flammable hydrogen gas and an also highly flammable graphite dope ...

Handbook of Microwave Component Measurements

Handbook of Microwave Component Measurements: with Advanced VNA Techniques, by Joel P. Dunsmore, provides state-of-the-art coverage for making measurements on RF and Microwave Components, both active and passive. A perfect reference for R&D and test engineers, with topics ranging from the best practices for basic measurements, to an in-depth analysis of errors, correction methods, and uncertainty analysis, this book provides everything you need to understand microwave measurements. With primary focus on active and passive measurements using a vector network analyzer, these techniques and analysis are equally applicable to measurements made with spectrum analyzers or ...

Mac's Radio Service Shop: A Windy Subject

Mac's Radio Service Shop: A Windy Subject, March 1953 Radio & Television News - RF CafeIt is a pretty good bet that most multi-element TV aerials you find on rooftops and even on ancient towers were decommissioned years ago. They have been replaced either with cable (whether via CATV or Internet) or satellite dishes. A few hold-outs still use them for local over-the-air broadcast stations and/or even FM radio reception. There was a time, though, that photographs taken looking across a vast expanse of house roofs showing an endless array of antennas and guy wires was a sign of 'modern' living. Most were erected by Harry Homeowner types or minimally qualified service technicians, and were well-known for toppling, twisting, bending or un-aligning when stiff winds were imposed upon them. This story-lesson from the March 1953 edition "Mac's Radio Service Shop," ...

Free Cemetery Plots Donated to Veterans in York, PA

Mount Rose Cemetery "Defenders of the Flag" Gravesites - RF CafeMelanie's mother, Mary Goodwin, has four (4) gravesites at Mount Rose Cemetery in York, Pennsylvania, that she would like to donate to the families of U.S. military veterans. They are located in the "Defenders of the Flag" area of the grounds, near the flagpole and cannon. Being in this reserved section, only honorably discharged veterans and their immediate family members are eligible to be laid to rest there. A qualified veteran is welcome to any or all of them for free. Mount Rose ...

ΞΞ   RF Cafe App v1.00   ΞΞ Now Available

RF Cafe App v1.00 Release! - RF CafeIt's been a lot of work with a steep learning curve, but at long last the first RF Cafe App is now available for download from the Google Play website! An iPhone version will probably be created if my motivation level is elevated enough by a huge number of downloads for this Android version. This first release is meant to 'test the waters' for the usefulness of an app whose purpose is to provide reference material rather than a collection of calculators. Whether you are in the lab, at your desk doing design work, or operating in the field, there are times when you need data. These first few screens are some of the most often needed information. If enough support is received, the RF Cafe App can be greatly expanded into a vast volume of formulas, sketches, tables, definitions, and other encyclopedic content not ...

EDI CON Expands into the U.S. Market

Microwave-Journal-EDI-CON-2016-USA-4-5-2015.htm" > Electronic Design Innovation Conference (EDI CON) Expands into the U.S. Market - RF CafeHorizon House Publications and Microwave Journal announce that their annual RF/microwave, EMC/EMI and high-speed digital Electronic Design Conference and exhibition, EDI CON, is expanding into the U.S. market after three successful events in Beijing, China. EDI CON China drew more than 2,600 attendees at the April 2015 event held at the China National Convention Center (CNCC). Thefirstfirst EDI CON USAEDI CON USA will take place September 20-22, 2016 at the Hynes Convention Center in Boston, Mass. Boston has an extensive electronic design industry especially in the RF/microwave area where many industry leading companies reside in the New England region. Horizon House president Microwave-Journal-EDI-CON-2016-USA-4-5-2015.htm" ...

Notable Tech Quote

"Benjamin Peirce 1857" by Daniel Huntington - http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Peirce_Benjamin.html. Licensed under Public Domain via Wikimedia Commons - RF Cafe"Gentlemen, that is surely true, it is absolutely paradoxical; we cannot understand it, and we don't know what it means. But we have proved it, and therefore we know it must be the truth." - Benjamin Peirce, on Euler's identity, as quoted by R. C. Archibald in his book Benjamin Peirce, 1809-1880 : Biographical Sketch and Bibliography. Also on the topic: "What could be more mystical than an imaginary number interacting with real numbers to produce nothing? The equation contains nine basic concepts of mathematics - once and only once - in a single expression. These are: e (the base of natural logarithms); the exponent operation; π; plus (or minus, depending on how you write it); multiplication; imaginary numbers; equals; one; and zero." - Robert P. Crease, in "The greatest equations ever" at PhysicsWeb (October 2004) <Quote Archive>

Kanwal F. Is the Second Winner in the April Book Drawing!

Precision FMCW Short-Range Radar for Industrial Applications - RF CafeKanwal F., of Fullerton, CA, is the second winner in the April 2015 RF Cafe Book Drawing. Kanwal selected Precision FMCW Short-Range

Radar for Industrial Applications. Each month I randomly draw one or two people's names from my 'electronic hat' (an Excel spreadsheet) to receive his/her choice of a book. This book was graciously provided by Artech House.

QuickSyn Lite Synthesizers Now Extended to mm-Wave

NI-QuickSyn-Lite-Synthesizer-Extended-Millimeter-Wave-4-30-2015.htm" > QuickSyn Lite Frequency Synthesizers Now Extended to Millimeter Wave - RF CafeNI Microwave Component's popular QuickSyn Lite frequency synthesizers are now extended to millimeter wave. The new synthesizer modules employ the same revolutionary phase refining technology that all QuickSyn products use to enable fast switching speed, low phase noise, compact size, and low cost. The modules are available in three popular bands - 27 to 40 GHz, 50 to 67 GHz, and 76 to 82 GHz - and are designed to supply medium power output. These new products present a very cost effective solution NI-QuickSyn-Lite-Synthesizer-Extended-Millimeter-Wave-4-30-2015.htm" ...

2015 Engineering School Rankings

Engineering School 2015 Rankings (U.S. News & World Report) - RF CafeU.S. News & World Report has released its engineering school rankings for 2015. The usual suspects are still at the very top of the list, with a couple swapping positions each year. However, what might be surprising is the number of state universities that occupy most of slots 8 through 24. Some that you would expect to see heading the list - like Cornell, Harvard, and Johns Hopkins - are beaten by State U. My guess is that holding a degree from MIT (#1 spot) is still a sure ticket to your job of choice, but news reports for the last few years show that institutional names do not hold the weight they used to as compared to a graduate's proven capability. A very strong mood of entrepreneurship is gaining popularity with college students who start businesses prior ...

Television in Space

Television in Space, August 1965 Electronics World - RF CafeA mere five years elapsed from the time Echo, a gas-filled metallized plastic sphere that passively reflected radio signals back to Earth, was launched and the time that 35 television cameras had been launched into space. The Space Race was at a fever pitch. Although the Ruskies beat us in being the first to launch both an active satellite (Sputnik) and a man (Yuri Gagarin) into space, America's deep pool of intellectual resources, consisting of both native scientists and many of the world's top scientists who chose to flourish in freedom here rather than oppression behind the Iron Curtain, fostered the advantage that in short order established the United States as the leading super power both in space ...

Congrats to April Book Drawing Winner Stephen M. !!!

Envelope Tracking Power Amplifiers for Wireless Communications - RF CafeStephen M., of Midland, Virginia, is a winner in the April 2015 RF Cafe Book Drawing. Stephen wisely selected Envelope Tracking Power Amplifiers for Wireless Communications, by Zhancang Wang. This book was graciously provided by Artech House. I sent a notice to a second winner, but have not heard back yet, so check your e-mail!

Directional Coupler Crossword Puzzle

Directional Coupler Crossword Puzzle for May 3, 2015 - RF CafeThis week's crossword puzzle has a 'directional coupler' theme in that many of the words are related to the devices. All of the other words are, as usual, pulled from a custom-built dictionary containing only terms pertaining to engineering, mechanics, astronomy, mathematics, chemistry, and names of companies that make components for the aforementioned fields. Even Dilbert characters appear sometimes. You will not, however, find names of numbnut Hollywierd celebs or TV shows here.

Resistance Measurements

Resistance Measurements, January 1946 Radio News - RF CafeThe advent of FET-input multimeters greatly reduced reading accuracy errors due to not taking into account the impedance of devices being measured. A certain amount of familiarity with how to interpret the indication on a meter movement on analog meters is still required based on the multiplier switch position and scale selected, but for most users simply reading the number beneath the pointer - or interpolating its position between two numbers - is good enough. Mirrored scales take the some of guesswork out of that by reducing parallax issues. Finally, digital multimeters (DMMs) hit the scene and made slackers out of just about all of us when it comes to making voltage, current, and resistance measurements. With few ...

Sivers IMA Launches Radar Development Kit

Sivers-IMA-Launches-Radar-Development-Kit-4-30-2015.htm" >Sivers IMA Launches Radar Development Kit - RF CafeSivers IMA, a leading manufacturer of millimeter wave products, today announced its launch of a Radar Development Kit (RDK) an easy-to-use platform for those who need to measure distance or speed of an object.  “At Sivers IMA we have a long experience of developing complete Sivers-IMA-Launches-Radar-Development-Kit-4-30-2015.htm" >radar sensor solutions and a portfolio of FMCW Radar sensor front-ends. For the RDK that we are now launching, we have taken some of our know-how and developed and packaged hardware and software to simplify for customers that are interested in including radar technology in their products Sivers-IMA-Launches-Radar-Development-Kit-4-30-2015.htm" ...

Windfreak Technologies Frequency Synthesizers - RF Cafe

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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