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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 typing up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe- Archive -

• Glasgow University Building 6G Test Centre

• Qualcomm Beats Skyworks and Qorvo in RF Front End Sales

• USAF Spectrum Warfare Strategy Causing COnfusion

• 5G FWA Market Will Be 40% of Total FWA Market by 2026

• New Ultrahard Diamond Glass Synthesized

• Dayton 2022 Hamvention Expects to Be Live Event

• Quantum Time Flows in Both Directions

• AT&T and Verizon Lower 5G C-Band Power

• October SEMI Billings up 0.6% M-o-M d 43.8M 5G Customers in October

Bell Telephone Laboratories - Miniaturization

Bell Telephone Laboratories - Miniaturization, November 1949 Radio-Electronics - RF CafeWhen many people hear the name of Bell Telephone Company, the first thing they think of is the court-directed breakup of Bell System into what became known as "Baby Bells" after being sued for monopolistic policies. What is too often forgotten - or more likely never realized - is the immense role Bell played in the building of America into an industrial and technology giant. Vintage magazines like this 1949 issue of Radio-Electronics as well as many other types including The Saturday Evening Post, Popular Mechanics, Family Circle, and many other publications commonly found in homes, contained full-page advertisements by Bell Telephone Laboratories promoting their work and reminding subscribers of how their hard-earned money was being invested on improvements. Along with the Interstate Highway System, America's robust, dependable, and high quality personal communications...

Technical Aspects of Naval Communications

Technical Aspects of Naval Communications, December 1950 Radio & Television News - RF CafeThe December 1950 issue of Radio & Television News magazine ran a series of articles on Navy communications. This was a mere four years after the end of World War II and right at the beginning days of the Korean War. Communist and fascist regimes never give the world a moment's rest (some - not me - think just being nice to them will cause them to be nice in return). Discussed here are issues still relevant to modern outfitting of naval assets with new or updated communications equipment. Unlike land-based systems, naval environments impose increased requirements for ruggedness due to harsh vibration, impact, and corrosion issues. Weight added above the waterline needs to be offset with weight below the water line to preserve stability. Reliability and personnel training also need to be increased because being at sea means access to replacement parts, operators, and service technicians are harder to accommodate...

Counterfeited Goods 2.5% of Total World Trade

2.5% of Total World Trade Involves Counterfeited Goods - RF Cafe"The trade of fake goods continues as the COVID-19 pandemic, chip shortages and other events push more criminals to find new ways to take advantage of unknowing buyers. Trading fake goods is bad for any industry, but it's particularly dangerous in the industrial electronics sector, where counterfeit components pose threats like short circuits, electrical shocks, fires, explosions and equipment failures. 'Counterfeiters work hard to mimic not only the product packaging but the actual product as well. Distinguishing fakes from real parts becomes very hard for consumers..."

Anatech Electronics November Newsletter

Anatech Electronics November 2021 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his November 2021 newsletter that features his short op−ed entitled "C-band and Altimeters: Bad Company? ," where he notes that even though FCC concluded that the AVSI study "does not demonstrate that harmful interference would likely result under reasonable scenarios," there is enough concern in the non-standardized radar altimeter realm to raise a red flag. As Sam points out, there is a full 500 MHz separation between the C-band wireless band and radar altimeters. Sam also presents some relevant industry news items as well, including Amazon planning to launch Kuiper satellite prototypes, and the DoD funding research that combines 5G and optical sensors.

Color TV Today

Color TV Today, September 1959 Popular Electronics - RF CafeWhen color televisions hit the stores in 1954, most households could not afford one. For that matter, most households could not afford a black and white TV, either. By 1959 when this article appeared in Popular Electronics magazine, TV in general was still a novelty to most people. It is amusing to read about how much more lifelike everything would appear when broadcast in "living color." Well, duh. It's as if it never occurred to anyone that the images previously did not contain color like the real world did. I was born in 1958, and remember that my family's was last of all the households I knew of to own a color television set. We never even had a console floor model, just small tabletop pieces of junk. It was a big deal the day I, at about age 16, bought and installed a remote rotor for the rooftop antenna so we could receive more than three stations. There was no cable TV service in our neighborhood...

RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later...

Many Thanks to Atenlab for Their Continued Support!

Atenlab microwave components - RF CafeAtenlab has been operating in Taiwan for more than a decade, and has sold and installed hundreds chambers around the world. Holistic, affordable Over-the-Air (OTA) measurement systems perform comprehensive measurement and test in a controlled environment. Compact Antenna Test Range (CATR) with one-touch operation supports multiple systems - 2G, 3G, 4G, 5G - and major instrument brands. [M]ulti-probe OTA measurement systems offer reduced time measurements over single-probe systems.

ARRL QST Technical Editor Joel Hallas, W1ZR, SK

Joel Hallas, W1ZR, Silent Key - RF CafeJoel Hallas, W1ZR, Silent Key - RF CafeThis is indeed unexpected and sad news. Joel Hallas, W1ZR, a long-time columnist for American Radio Relay League (ARRL) publications and an author of multiple books, has left this old world after 79 years. Since joining the ARRL in 2010 and receiving the monthly QST magazine, his "The Doctor Is In" column was always the first thing I read. Mr. Hallas was a master at using EZNEC (soon to be free) antenna simulation software and used it often to answers readers' questions. Decades of hands-on experience setting up, operating, troubleshooting, and teaching amateur radio subject made him an encyclopedia of knowledge. Joel's family surely knows how admired he was by the hundreds that knew him personally and the thousands of us who knew him through his works. RIP, Joel Hallas.

Simpson Electric Company Vacuum Tube Volt-Ohmmeter

Simpson Electric Company Vacuum Tube Volt-Ohmmeter, November 1949 Radio-Electronics - RF CafeThose of us old enough to remember the classic Simpson volt-ohmmeter (VOM) from the 1970s will look at this 1949 model appearing in Radio-Electronics magazine and probably not notice much if any difference. The basic case design is similar and it appears to be about the same physical size. The selector switches and potentiometer knobs look familiar as well. The primary difference is what is inside - a vacuum tube rather than a field-effect transistor (FET). The Simpson Model 303 is a vacuum tube voltmeter (VTVM - actually a VTVOH). Prior to the availability of FETs with their very high input impedance characteristic (10 MΩ or greater), a vacuum tube input stage was needed to isolate the device (or circuit) under test (DUT) from the relatively low impedance of the resistor-based volt-ohm meter (VOM - as with the Simpson Model 260) meter circuitry. The problem is that a low VOM impedance...

RF Control of Superconducting Quantum Processors

RF Control System of Superconducting Quantum Processors - RF CafeA team of physicists and engineers at Lawrence Berkeley National Laboratory successfully demonstrated the feasibility of low-cost and high-performance radio frequency modules for qubit controls at room temperature. They built a series of compact RF modules that mix signals to improve the reliability of control systems for superconducting quantum processors. Their tests proved that using modular design methods reduces the cost and size of traditional RF control systems while still delivering superior or comparable performance levels to those commercially available. Their research, featured as noteworthy in the Review of Scientific Instruments and selected as a Scilight by the American Institute of Physics..."

Rationalizing Pi

Rationalizing Pi, Kirt's Cogitation #262 - RF Cafe...During my last session on the cursed elliptical machine, for some reason I was contemplating pi (π). Pi has been an enigma in the realm of mathematics and physics since it was first recognized as being irrational The fact that the ratio of a circle's circumference to its diameter is an inexact number has caused enormous amounts of consternation for dogged investigators of the aforementioned phenomenon. Pythagoras is believed to have first noticed the irrationality of certain numerical ratios when even something as basic as the corner-to-corner diagonal of a unit square could not be calculated to a finite precision. In some religious circles even contemplating such thoughts caused souls to be burned at the stake for daring to assert that such an imperfection could exist in a perfectly created world. Recall that Galileo was excommunicated for asserting that the earth was not the center of the universe...

R&S Demos Robust Data Link Comms for Rotary Wing Aircraft

Rohde & Schwarz Demos Robust Data Link Communication for Rotary Wing Aircraft - RF CafeRohde & Schwarz, together with ESG Elektroniksystem- und Logistik-GmbH and representatives of the German armed forces (Bundeswehr), successfully carried out stationary tests on the premises of the Bundeswehr Technical Center for Aircraft and Aeronautical Equipment (WTD 61) in Manching. The influence of rotors on radio waves was tested on two types of helicopters, operational with the Bundeswehr, the CH53 and Tiger, as well as on the rotary wing UMAT R-350 UAV from ESG. Piloted and unpiloted rotary-wing aircraft of the Bundeswehr need to be able to send data links through one or more rotor planes, where interference can by caused by rotor blade modulation. The successfully completed tests demonstrated how robust the radios are against level drops, phase shifts and diffraction at rotor blades' edges; while digital voice and data transmission was possible at the highest sensitivity. In addition, a comprehensive set of data was collected to develop robust waveforms for broadband data transmission...

Super-Radars for Missile Ships

Super-Radars for Missile Ships, July 1957 Radio & TV News - RF CafeThe term "super-radar" would be sort of meaningless these days since just about everything is "super" anymore, especially with regard to military, space, or aerospace systems. Not so in 1957 when this Radio & TV News magazine article appeared. Lately, when I hear the term "super-something," I think of a really funny radio commercial with a meeting of super-geniuses. I don't recall the exact subjects, but the chairman asks his members for items to add to their agenda of things to do. Someone pipes up with an idea to solve world hunger, then another suggests they design a nuclear fusion generator to power the world with clean energy, etc. Enthusiasm exudes from the empaneled super geniuses. Finally, someone suggests that they do whatever it is the commercial is trying to promote (I don't remember what it is), upon which silence falls over the room and an incredulous person says, "We're super geniuses, but we're not super super geniuses...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Please Visit Triad RF Systems to Thank Them for Their Support

Triad RF SystemsTriad RF Systems designs and manufactures RF power amplifiers and systems. Triad RF Systems comprises three partners (hence 'Triad') with over 40 years of accumulated knowledge of what is required to design, manufacture, market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating amplifiers are available, in formats including tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology partner than a vendor for our line-of-sight communications product line." Please check to see how they can help your project.

Microwaves Part VII - Below-Cutoff Waveguide

Microwaves Part VII - Below-Cutoff Waveguide Attenuators & TR Switches, November 1949 Radio-Electronics - RF CafeHere is the final installment of C.W. Palmer's "Microwaves" series of article in Radio−Electronics magazine. Topics for all seven parts are shown below. Unlike the previous parts, this one discusses uses for waveguide below its cutoff frequency for switching and attenuation purposes. Of course there is also the filter application as well which exploits the high attenuation in the cutoff region. Since these pieces were written in the pre-solid state semiconductor era, vacuum tubes appear as control and amplifier devices rather than diodes and transistors, but don't let that deter you from benefitting from the useful waveguide characteristics lessons presented...

Flexible Antenna Array Coat Airplane Wings

Flexible Antenna Array Coat Airplane Wings - RF Cafe"Princeton University researchers have taken a step toward developing a type of antenna array that could coat an airplane's wings. The technology, which could enable many uses of emerging 5G and 6G wireless networks, is based on large-area electronics, a way of fabricating electronic circuits on thin, flexible materials. The approach overcomes limitations of conventional silicon semiconductors, which can operate at the high radio frequencies needed for 5G applications but can only be made up to a few centimeters wide and are difficult to assemble into the large arrays required for enhanced communication with low-power devices. With an airplane, because its distance is so far, much signal power is lost. Since wings are a fairly large area, a single-point receiver on the wing does not help but if the amount of area..."

The Tube Family Tree - Magnetrons & Klystrons

The Tube Family Tree, Magnetrons & KlystronsAugust 1963 Popular Electronics - RF CafeMagnetron, photomultiplier, traveling wave, compactron, klystron, backward wave, pencil, lighthouse, cathode ray, indicator, nuvistor, acorn, peanut, T−R, electrostatic, cat's-eye, orithon, and loctal, are just a few of the many types of vacuum tubes that have been and in some cases still are in use in various types of electronic equipment. Some you have heard of, others you probably have not. All are discussed in a series of three articles published in Popular Electronics magazine. This is part 3, which includes operational descriptions of klystrons, magnetrons, and traveling wave tubes (radar & satellite communication), all of which are still designed into new products today...

Exodus 4 kW, S-Band Solid State Pulse Amplifier

Exodus Advanced Communications 4 kW, S-Band Solid State Pulse Amplifier - RF CafeExodus Advanced Communications' new model AMP2136P-4KW is a 2.0-4.0 GHz, 4 kW pulse amplifier that is designed for pulse/HIRF, EMC/EMI Mil-Std 461/464 and radar applications. Other frequency ranges & power levels available - all providing superb pulse fidelity. Up to 100 μsec pulse widths, up to 6% duty cycles with a minimum 66 dB gain. Available monitoring parameters for forward/reflected power in watts & dBm, VSWR, voltage, current, temperature sensing for outstanding reliability and ruggedness in a compact 10U chassis...

The Tube Family Tree, Part 1

The Tube Family Tree, Part 1, May 1963 Popular Electronics - RF CafeFor some inexplicable reason I went backwards on this three-part Tube Family Tree series that appeared in Popular Electronics. Author Louis Garner, Jr., starts out with the early history of vacuum tubes, beginning with Thomas Edison's incandescent light bulb and then quickly progresses to Lee de Forest's Audion amplifier tube, and on through the evolution of multi-grid vacuum tubes that are specially designed for low noise receiver front ends, high power transmitters, voltage and current regulators, video cameras, pulse forming networks, traveling wave tubes, and many other types. There is quite a bit of information and history contained in these three installments that will do a very nice job of introducing you to the wonder... Here you can read Part 1, Part 2 and Part 3

RF Cascade Workbook

RF Cascade Workbook - RF CafeRF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

Thanks Once Again to everythingRF for Long-Time Support!

everything RF Searchable Database - RF CafePlease take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 267,269 products from more than 1397 companies across 314 categories in their database and enable engineers to search for them using their customized parametric search tool. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you.

The Radio Month - Industry News

The Radio Month, November 1949 Radio-Electronics - RF Cafe"The Radio Month" news column from the November 1949 issue of Radio−Electronics magazine contained much interesting information. At the top of the list was an announcement that an all-electronics system for color television implementation had been presented to the FCC. It was one of three such systems vying for official adoption as an industry standard. CBS (Columbia Broadcasting System), CTI (Color Television, Inc.), and RCA (Radio Corporation of America) were in stiff competition. Here is a January 1951 Radio−Electronics article describing the three systems. Ultimately, the NTSC forged its own standard that incorporated an all-electronic system that was also backward-compatible with the existing black and white (B&W) system. Also included was information about the first Philadelphia Radio Service Men's Association (PRSMA) meeting. It was sort of an IEEE for electronic service technicians...

Television - As I See It

Television - As I See It, January 1945 Radio News - RF CafeNow that the inestimable Bob Pease is no longer with us to enlighten and entertain, is there a contemporary and immediately recognizable electronics technology name you see on a magazine article, book, or presentation? Maybe my tech literary world is pretty small, but nobody come to mind as I write this (apologies to the many great authors I am forgetting). In the early part of the last century, you can be sure that when the names Edison, de Forest, Tesla, Marconi, Bell, and Morse were featured in bylines, readers took note. Lee de Forest's 1945 article in this 1945 Radio-News magazine on the state of the art of television was an example. No doubt many reports on TV were written, published, and passed over, but when one of the Greats of the industry put pen to paper it will be noticed. It worked with me...

Apple Self-Service Repair for iPhones, Macs

Apple Self-Service Repair for iPhones, Macs - RF CafeHere is a major paradigm change from Apple's traditional "No user serviceable parts inside" philosophy. "Apple said it plans to launch a self-service repair program in 2022 that would allow consumers for the first time to fix their own iPhones and Macs with Apple parts, tools, and manuals, a prominent shift in the consumer electronics giant's stance on the repair process. The new Self Service Repair program will be available first for the company's most recent iPhone 12 and iPhone 13 lineups in early 2022. It will later expand to Mac computers featuring Apple's M1 processors, the company said on Wednesday. Under the new program, customers will be able to fix their own devices, starting with the display, battery, and camera modules in the iPhone, using genuine parts, tools, and repair manuals distributed by Apple..."

Arvin Model 35 8-Tube Car-Radio Receiver

Arvin Model 35 8-Tube Car-Radio Receiver, May 1936 Radio-Craft - RF CafeThis is another Radio Service Data Sheet that appeared in the May 1936 edition of Radio-Craft magazine. I post this schematic and functional description of the Arvin Model 35, 8-Tube Car-Radio Receiver manufacturers' publications 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. A WWW search for an Arvin Model 35 Car Radio did not turn up any results, but I did see the unknown model shown here on an expired eBay auction. It has a speaker front that looks like the Model 35. Installing and servicing the earlier heavy, bulky car radios was the source of many electronic-themed comics and articles. Some of the very earliest two-way radio sets (of which this is not) had massive transformers, needed to generate power for the transmitter...

NASA Throws a DART to Deflect Asteroid

NASA Throws a DART to Deflect Asteroid - RF Cafe"The Double Asteroid Redirection Test (DART) mission is directed by NASA to the Johns Hopkins Applied Physics Laboratory with support from several NASA centers: the Jet Propulsion Laboratory, Goddard Space Flight Center, Johnson Space Center, Glenn Research Center, and Langley Research Center. DART is a planetary defense-driven test of technologies for preventing an impact of Earth by a hazardous asteroid. DART will be the first demonstration of the kinetic impactor technique to change the motion of an asteroid in space. The DART mission is led by APL and managed under NASA's Solar System Exploration Program at Marshall Space Flight Center for NASA’s Planetary Defense Coordination Office and the Science Mission Directorate's Planetary Science Division..."

High Power Crystal Set

High Power Crystal Set, August 1960 Popular Electronics - RF CafeMost regular RF Cafe visitors will probably not be too interested in this 1960 Popular Electronics magazine article, but there are a lot of people who build and/or repair vintage radio gear and search the Internet for helpful information. Having built a couple crystal radio sets as a kid, I've always been amazed at how a few picowatts of RF energy can be received, processed, and heard through an ear plug without the need for external power from a battery. Speaking of crystal radios, I remember one time while working as an electrician in Annapolis, Maryland, (prior to entering electronics) I had a telephone handset for use in communicating with other electricians in a building I was wiring, and it picked up the local AM radio station. A pair of the old style handsets with carbon microphones would, with the help of a single 'D' cell in series, function as a very acceptable intercom system using two standard electrical wires between them...

"Xi Restored" Crossword Puzzle for November 28th

"Xi Restored" Engineering Crossword Puzzle for November 28th, 2021 - RF CafeDue respect is paid throughout this technically themed crossword puzzle to the Greek letter "Xi," which has been dissed by the World Health Organization by omitting it from the succession of designations for new COVID−19 variants (look for an asterisk after the clue). Xi has been restored to its rightful place as the 14th letter in the Greek alphabet. Only clues and words are directly to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other science subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars...

The Letter "Xi" Stricken from Greek Alphabet

WHO skips Xi COVID-19 variant going from Nu to Omicron - RF CafeThis gives a whole new meaning to "Political Science." Vaccinated people have been generating and shedding variants of COVID−19. WHO designates each new variant with progressive letters in the Greek alphabet, beginning with Alpha. Until a few days ago they were up to the Nu variant. Next came Omicron. "What happened to Xi?" you might reasonably ask. It so happens that Xi (Jinping) is the name of China's dictator, so "the Science" we are admonished to listen to decided to omit it. Now we need the Ministry of Truth to replace all former references to Xi (Ξ, ξ) with some other symbol. Let me be the first to suggest a spiked virus icon Coronavirus Icon - RF Cafe. Damping ratio henceforth is written as Coronavirus Icon - RF Cafe = 2.5 rather than the traditional ξ=2.5. Similarly there is the Coronavirus Icon - RF Cafe baryon (rather than the Xi baryon), the Riemann Coronavirus Icon - RF Cafe function, potential difference is Coronavirus Icon - RF Cafe volts, the Scientific Research Honor Society is now Sigma Coronavirus Icon - RF Cafe. You get the idea...

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