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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...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

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Homepage Archive - August 2021 (page 4)

See Page 1 | 2 | 3 | 4 of the August 2021 homepage archives.

Tuesday the 31st

Radio Data Sheet 333 for General Electric Model 100

Radio Data Sheet 333 General Electric Models 100, 101, 103 and 105, March 1946 Radio-Craft - RF CafeIt has been a while since posting on of these Radio Data Sheet 333 that often appeared in vintage electronics magazines like Radio-Craft. This one is for General Electric Radio Models 100, 101, 103 and 105. The RadioMuseum.org website has a very nicely restored General Electric Model 103 radio. Per their description: "The General Electric 103 is an AC/DC operated 5 tube BC band receiver. The BC band frequency tuning range is 540-1600 kHz. Has built-in loop antenna with provisions for connecting an external antenna. The following models use the same schematic and chassis but have different cabinets..." A few Model 100 versions show up on eBay in case you might be interested in acquiring one...

Exodus 400-1000 MHz, 4 kW SSPA

Exodus Advanced Communications AMP2123P-4KW, 400-1000 MHz, 4 kW Solid State Pulse Amplifier - RF CafeExodus Advanced Communications introduces the AMP2123P-4KW, a robust 400-1000 MHz, 4 kW Pulse Amplifier for Pulse/HIRF, EMC/EMI Mil-Std 461/464 and Radar applications. Up to 100 μsec pulse widths, up to 6% duty cycles with a minimum of 66 dB gain. Providing superb Pulse fidelity, excellent rise/fall times, monitoring parameters for Forward/Reflected power in Watts & dBm, VSWR, voltage, current, temperature sensing for unprecedented reliability and ruggedness, and local LCD & remote flexible interfaces, all in a compact 10U chassis 17.5"H x 19"W x 22"D nominally, weighing in at 45 kg 45 kg...

Microwave EM Weapons May Prevail over Lasers

Microwave EM Weapons May Prevail over Lasers - RF CafeThe U.S. military is racing to deploy new weapons to tackle the threat from small unmanned aerial vehicles (UAVs). That means countering several attackers simultaneously, and microwave-based electromagnetic weapons are considered the obvious choice. Laser weapons may look like a solution: precise, speed-of-light-operation, and an infinite magazine, but they have a problem with dwell time. This is the amount of time necessary to hold the laser on target to bring it down. A typical tactical laser can take as long as five seconds. If a laser weapon only can acquire small drones from two kilometers away, then a few dozen cheap drones will overrun the million-dollar laser. Microwaves work differently. A burst of high-intensity microwaves will overload electronics, causing many failures and knocking a drone out of the sky instantly. The microwave weapon also can swat whole unmanned swarms at once...

Get in the Scrap!

Get in the Scrap!, September 1942 Radio Retailing Today - RF CafeAn extraterrestrial threat to existence, be it an impending asteroid strike or an intelligent being's announced intention to do harm to the earth, would probably be required these days to invoke the sort of voluntary personal sacrifices of today's average citizen that was exhibited in the enthusiastic, patriotic response by Americans to the 'V' for Victory campaign during World War II. You no doubt have seen pictures of kids pulling wagons filled with metal scrap, rubber tires, and glass milk and pop bottles collected for the war effort, and pickup trucks piled high with sections of pipe, car parts, and retired furnaces. Resources were relatively scarce at the time, and material was being consumed very quickly in the effort to beat back the aggressive advances of Axis forces throughout Europe, northern Africa, and the South Pacific. This article from a 1942 edition of Radio Retailing Today encouraged radio repairmen to check with customers during service calls...

Modelithics COMPLETE+3D Library v21.6 for Ansys HFSST

Modelithics® Releases the COMPLETE+3D Library™ v21.6 for Ansys HFSST - RF CafeModelithics is pleased to announce the release of version 21.6 of the COMPLETE+3D Library for use with Ansys HFSS. The library contains nearly 350 highly scalable Microwave Global Models™ for capacitor, inductor, and resistor families from many popular vendors, plus Modelithics' collection of nearly 500 3D geometry models for inductors, capacitors, filters, packages, and connectors. This library now represents a total of more than 24,000 individual components with circuit and 3D electromagnetic (EM) models. Version 21.6 adds 6 new part value-, pad-, and substrate scalable Global Models for circuit models and 88 new full wave 3D EM models. New 3D EM models are available for 5 ATC capacitor series, 13 AVX capacitor series, 18 Barry Industries packages, Johanson's R05L and R07S capacitor series, 5 Kemet capacitor series, 11 Murata capacitor series...

Thanks to PCBONLINE for Continued Support!

PCBONLINE - RF CafePCBONLINE supplies complex rigid and flex-rigid printed circuit boards (PCBs),and one-stop production with maximum flexibility ranging from prototype sample to mass production. Rigid-flex, HDI, multilayer, IC-loadboard, LCP 5G optical module, ceramic, MCPCB. Materials include Rogers, Taconic, Arlon, Isola, Bergquist, Kapton, Panasonic, and more. After more than 15 years of continuous efforts, PCBONLINE constantly updates our equipment, improves our technology, and serves you with the highest quality. Cost and delivery quotations online without the need for multiple phone call and/or e-mails.

Monday the 30th

RCA Radio - Cost Reduction

RCA Radio - Cost Reduction, March 1946, Radio-Craft - RF CafeIf you have seen many of the articles I post from vintage electronics magazines, you know I often compare prices from the magazine's era to today's prices. The online Inflation Calculator from the Bureau of Labor Statistics (BLS) is as good as any, so it is used. This RCA advertisement in a 1946 issue of Radio-Craft magazine boasts of how drastically the cost of vacuum tubes has come down since 1923. It claims a $9 tube in 1923 costs a mere 80¢ in 1946; that is about 1/11th of the original price. Prior to around 1965, inflation was very low, so the inflation-adjusted price for the $9.00 tube would be $9.80 in 1946 - a full 23 years later (a 9% increase, per the BLS). Therefore, the 80¢ price is an even better deal. Let us compare that to what a $9 item 23 years ago (1998) from today (2021) would cost now. Per the BLS Inflation Calculator, it would take $15.06 in 2021...

Analog Isolation Techniques for Your Next Circuit Layout

Circuit Design: Analog Isolation Techniques for Your Next Circuit Layout - RF CafeThe following article entitled "Circuit Design: Analog Isolation Techniques for Your Next Circuit Layout" was prepared for and submitted to RF Cafe by its author, Suresh Patel, of MerMar Electronics. He wrote asking whether he could provide an article on an aspect of PCB design relevant to RF Cafe visitors, so I suggested addressing the issue of placing digital and analog / RF signals on a common substrate. Below is his submission which briefly discusses that as well as power supply isolation. At MerMar Electronics, we have a dedicated team of employees for manufacturing aerospace printed circuit boards in California, USA. With 40 years of experience and an advancement in circuit board technology, our team provides excellent DFM assistant, expert review of printed circuit board design. We have an in-house engineering team & make sure the final deliverables of aerospace PCB assembly are robust, secure and reliable...

Silicon-Based Optical Tunnel Yields 4-Channel, 350 THz Multiplexer

Silicon-Based Optical Tunnel Yields 4-Channel, 350 THz Multiplexer - RF Cafe"The terahertz band promises multiple benefits due to its potential for high-speed, wideband communications, but system designers are hampered by a lack of basic electronic building-block components such as amplifiers, switches, and multiplexers / demultiplexers. Among the reason for this component 'gap' is that these terahertz waves (generally considered as being between 100 GHz and 10 THz, corresponding to wavelengths between 3 mm and 30 µm) reside in the challenging spectrum zone between the more conventional RF frequencies ranging into the tens of gigahertz and the optical world with its nanometer wavelengths. This component shortfall is known to researchers who are striving to leverage silicon and its related design and facilitation technology into optical physics to provide useful THz-range components..."

Vintage Taylor Tubes Advertisement

Vintage Taylor Tubes Advertisement, February 1941 QST - RF CafeSome of us like seeing the old advertisements from vintage era magazines. This Taylor Tubes advertisement from the February 1941 edition of the ARRL's QST magazine is a prime example. Vacuum tubes had a high degree of automation for stamping out internal components, forming the glass shells and evacuation of the air, but they still required human production line operators for assembling the components prior to being encapsulated and sealed. National Instruments hadn't invented LabVIEW yet to run the testing station, so people manually placed the tubes into a board full of sockets for burn-in and testing...

USAF Charles Pritt Info on MPN-14 & TPN-19 Radars

Note from Charles Pritt re MPN-14 and TPN-19 radars from the USAF 3rd MOB - RF CafeFellow USAF radar technician Charles Pritt checked in with a plethora of info and photographs about his time in the 3rd MOB (aka 3CCG or 3rd Combat Communications Group). Says Charles: "I attended Technical training at Keesler, from April to September 1973, for Radar Repair. My first assignment after Technical school was to the 1837th E&I squadron at Yokota AB, Japan starting in October 1973. Since we were not supporting a daily operational radar system and the only time we worked on Radar was when we went on TDY, we usually just sat around the office, talking, drinking coffee or studying radar books for our promotions..."

Faraday Invented the Electric Motor 200 Years Ago 

Faraday Invented the Electric Motor 200 Years Ago - RF Cafe"On 3 September 1821, Faraday observed the circular rotation of a wire as it was attracted and repelled by magnetic poles. He sketched in his notebook a clockwise rotation around the south pole of the magnet, and the reverse around the north pole. 'Very satisfactory,' he wrote in his entry on the day's experiment, 'but make more sensible apparatus.' The next day, he got it right. He took a deep glass vessel, secured a magnet upright in it with some wax, and then filled the vessel with mercury until the magnetic pole was just above the surface. He floated a stiff wire in the mercury and connected the apparatus to a battery. When a current ran through the circuit, it generated a circular magnetic field around the wire. (be sure to watch the video)..."

Sunday the 29th

Radio Theme Crossword Puzzle for August 29th

Radio Theme Crossword Puzzle for August 29th, 2021 - RF CafeThis Radio Theme crossword puzzle for August 29th, 2021, contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Tuesday the 27th

Don't Underrate Transistors

Don't Underrate Transistors, September 1960 Electronics World - RF CafeTransistors always have been and always will be prone to damage or destruction if operated at temperatures higher than their designed ranges. Modern foundry processes have made it possible for greater heat tolerances for a given transistor size, but care must be taken during circuit design to assure that the devices will under normal ambient conditions not exceed their intended temperature range. Often a heatsink is required in order to use a transistor at its full rated temperature, and sometimes extensive measures are needed to keep the heatsink within an acceptable maximum temperature. Take a look inside your computer for an example of how far heatsink technology has come. The liquid-cooled (desktop) and heat pipe-cooled (laptop) schemes are amazingly efficient and capable of dissipating heat from the CPU package, which would otherwise fry in milliseconds without it...

Terahertz Radiation Created Using Semiconductor Surface States

Terahertz Radiation Created Using Semiconductor Surface States - RF Cafe"A highly efficient way to convert optical photons into terahertz radiation has been developed by researchers in the US and Germany. The team, led by Mona Jarrahi at the University of California, Los Angeles, showed how the electric fields associated with semiconductor 'surface states' can be used to create electrons that emit radiation in the terahertz range. Terahertz radiation falls between infrared light and microwaves in the electromagnetic spectrum and has a range of potential applications including security scanning and medical imaging. However, creating practical sources of terahertz radiation is challenging..."

Vintage Slide Rule Calculators

Cardboard Slide Rule Calculators Donated by Gary Steinhour - RF CafeSlide rules have come in different formats over the years. The most familiar is probably the 3-part model with a fixed outer frame and a sliding inner rod, and a sliding clear window with a reticle line etched into it for aligning numbers (the cursor). While far from being any type of "collection," I do have a couple nicely preserved models. The ones from Keufel & Esser (K&E) are at the top of the table below. The Beginner's slide rule model is very basic with graduations on one side and some conversions on the other. The best of all is the Pickett N600-ES Log-Log that is in new condition and actually still has the box, leather case, instructions and certificate. The Pickett N600-ES is the slide rule model that went to the moon* with the Apollo astronauts (not the one I own, of course)...

World's 1st Flat Screen Display?

Electronics News, October 1957 Popular Electronics - RF CafeRibbon cable has been around and familiar to most of us for as long as we can remember. The advent of personal computers in the 1980s brought ribbon cable into the homes of millions of people in the form of the interface to disk drives. In 1957, however, when this news story appeared in Popular Electronics, ribbon cable, known initially as "tape cable," was just being introduced to industry. There was also a story on what might have been the first flat panel display screen, the "Sylvatron," photoconductance device developed by Sylvania. Commercial versions for TV sets were at least four or five years away (more like three decades away). Finally, we have a report on bouncing radio signals off the moon for calibrating newly commissioned satellite tracking stations, which, at the time the story was written, was waiting for the world's first artificial satellite, Sputnik I, to launch...

New for 2021! RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

Many Thanks to Withwave for Continued Support!

Withwave RF & Microwave Components - RF CafeWithwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Tuesday the 26th

Bell Telephone Labs - Inertial Navigation

Bell Telephone Laboratories - Inertial Navigation, September 1960 Electronics World - RF CafeUntil seeing this Bell Telephone Laboratories promotion in a 1960 issue of Electronics World magazine, I never considered that programming an autonomous missile for long distances and long flight times in the days before GPS required compensation for the Earth's rotation. Also, even though an intercontinental ballistic missile (ICBM) would spend a relatively small amount of time in the atmosphere during boost and reentry / terminal phases, wind effects would also need to be factored in to the onboard inertial guidance system's navigation program. Bell Labs was evidently tasked to design a system which could launch from the U.S. and fly to a target 6,000 miles away, and hit a designated spot closely enough to do the intended damage. According to the online great circle distance calculator, the trajectory from Lincoln, Nebraska, to Moscow, Russia (USSR in 1960) is 5,258 miles, so it is reasonable to assume the chore had similar start / stop locations in mind...

Gallium Oxide White LED Prospects

Gallium Oxide White LED Prospects - RF Cafe"Saga University in Japan has reported work towards white light-emitting diodes (WLEDs) based on rare-earth (RE)-doped gallium oxide (Ga2O3). The researchers adopted a vertical integration strategy with Ga2O3 layers doped with thulium (Tm), europium (Eu) and erbium (Er) grown on top of each other. The team comments that 'films grown by lateral integration are deposited side-by-side, while the co-doping of multiple rare earth elements into the same host will unavoidably degrade the crystal quality and, thus, induce undesirable threshold voltage and luminous efficiency.' The team adds: 'On the other hand, compared with phosphor-assisted WLEDs, direct white light emissions are achieved from single-material-based LEDs..."

ConductRF Ruggedized Replacement VNA Cables

ConductRF Ruggedized Replacement VNA Cables - RF CafePrecision Ruggedized VNA Cables from ConductRF offer RF Engineers great alternatives to costly OEM cables that are now past their best days. We have standards for applications at 18 GHz, 27 GHz, 40 GHz, 50 GHz & 70 GHz. Our torque resistant connector heads and phase stable constructions ensure great performance for many tests to come. ConductRF VNA series provides customers with reliable ruggedized solutions for Lab and Production Vector Network Analyzer testing. With options for 18 GHz, 26.5 GHz, & 40 GHz, these cables offer cost leading alternatives to original OEM VNA cable solutions. VNA Series cables are enhanced with a stainless steel spiral armor, providing protection from excess bending and crushing forces. A black non-conductive outer cover completes the product. These cables are phase stable during flexing and have an operating life cycle...

Thanks Again for Windfreak Technologies' Continued Support!

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Station Design for DX

Station Design for DX - Part I, September 1966 QST - RF CafePaul Rockwell wrote a 4-part series on station design for long distance communications (DX) that covered antenna selection and siting (Part I), economics and construction (Part II), station configuration and receiver topics (Part III), and propagation quirks and operating tips (Part IV). This first part goes into some of the gory detail of surrounding terrain considerations and necessary antenna launch angles, complete with equations. Most of the work is based on multi-element horizontal Yagi antennas. The term "forezone," of which a formal definition is not locatable in a Google search (no reference to it at all), is used throughout the series, and refers to the radiation area in the forward direction...

Abandoning State-of-the-Art Equipment in Afghanistan - What the?

Abandoning State-of-the-Art Equipment in Afghanistan - RF CafeI was in the USAF in 1979 when the U.S. embassy in Iran was captured and its personnel were held hostage. Some members (not I - too new) of the 5th Combat Communications Group deployed to set up forward communications in Saudi Arabia. We all got a briefing on how to destroy equipment if forced to abandon it due to enemy action. Page IV of the recently posted WWII era Keyer TG−10 tech manual contains a Destruction Notice in case of imminent capture. The military has been doing this for over half a century. Why, then, did they just abandon $billions$ worth of state-of-the-art aircraft, land vehicles, communications equipment, and armament in the hands of Al Qaeda and the Taliban? What the &*#%^! is going on here?

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafePCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.

Tuesday the 25th

Mac's Radio Service Shop: Handling Complaints

Mac's Radio Service Shop: Handling Complaints, September 1954 Radio & Television News - RF CafeOften I have said I would like to have been born three decades earlier to have lived during the golden era of radio and TV, and owned a local service shop. Having arrived on Earth in 1958, by the time I was old enough to consider electronic servicing as a career, the industry was in full transition mode to solid state electronics. I remember the TV repair guy working in our living room with tools and test equipment spread out on the floor. Growing up in a lower middle class (or maybe it was an upper lower class) household, our television and radios (both in the house and in the old 6−cylinder Rambler) used vacuum tubes until sometime in the 1970s. Transistorized stuff was for the rich folk in the neighborhood over. Upon enlisting in the USAF in 1978, the air traffic control radar I worked on used vacuum tubes for the primary airport surveillance (ASR) radar and for the precision approach radar (PAR)...

Cuprate Superconductors Contain Strange Component

Cuprate Superconductors Contain Strange Component - RF Cafe"Nobody really understands why cuprates - highly-doped copper oxides - are high-temperature superconductors, and researchers in the UK and the Netherlands have now discovered that the materials don't conform to conventional theories in their metallic state either. Instead, the researchers suggest that cuprates may contain a mix of 'strange' and conventional metallic components, but this only poses a further question: which component is responsible for the cuprates' superconductivity? Superconductivity occurs when a material loses all resistance to an electrical current below a certain critical temperature. Conventional theory states that at this critical temperature, the electrons in the material overcome their mutual repulsion..."

Coaxial Cable Equations

Coaxial Cable Equations Formulas - RF CafeMost professional engineers and technicians will never have the need to calculate the capacitance, inductance, or impedance of a coaxial cable since they are usually designing systems using well-defined components that are manufactured to exacting specifications. Students, hobbyists (Ham radio operators), and research types are probably the ones most likely to actually plug numbers into a calculator. For those people, I present these equations. Be very careful to realize that at frequencies far from DC, factors like skin depth and effective inner and outer conductor diameters may be significantly different than the physical measured values, and that can significantly affect real world results. Therefore, be sure to consult manufacturers' published data before making a final decision. I leave it to other sources to provide the complex equations needed to precisely model coaxial cables...

Many Thanks to Aegis Power Systems for Their Continued Support!

Aegis Power Systems - RF CafeAegis Power Systems is a leading supplier of AC-DC and DC-DC power supplies for custom and special applications. Aegis has been designing and building highly reliable custom power supplies since 1995. They offer a complete line of switch mode power supplies and power converters for a variety of markets including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom, and embedded computing applications. Design and manufacture of custom power supply solutions to meet each customer's exacting specifications. Please visit Aegis Power Systems today.

Skyworks Intros L, S and C Band Ceramic RF BPFs

Skyworks Intros L, S and C Band Ceramic RF Band Pass Filters - RF CafeSkyworks is pleased to introduce its L, S and C Band Ceramic RF Band Pass Filters for GPS, TCAS, Portable Transceiver, Homeland Security Radio, 5G, IOT and medical-based systems. These products are in production and loose samples are currently available. Skyworks offers a family of ultra-small profile filters available in surface-mount technology (SMT) designs. We can design and manufacture filters from 200 MHz up to 8 GHz, with high power handling ability up to 10 W, continuous wave (CW). We also offer rapid response times on all filter design requirements. The small-profile ceramic filter designs offer customers the option to go with a lighter weight, and reduced X-Y-Z dimensions as solutions to their requirements. These ceramic filter solutions allow design flexibility beyond traditional ceramic styles...

Snow Static Being Beaten by Flying Laboratory

"Snow Static" Being Beaten by "Flying Laboratory", January 1938 Radio-Craft - RF CafeTriboelectric charging is the phenomenon whereby adhesion forces between two surfaces causes the dislodging of electrons from nearby atoms, with those electrons being attracted to the material with the highest positive potential as the interface attempts to neutralize itself. Relative contact motion (friction; e.g., walking across a carpet) is most often the cause of triboelectric charge transfer, but simply pulling apart two dissimilar surfaces can also be the mechanism (e.g., pulling a wool sweater off or lifting a polymer type fabric blanket away from a bed sheet) for charge transfer. Electrostatic discharge (ESD), a manifestation of triboelectric charging, can damage or destroy electronic components...

New for 2020! 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...

Please Visit Empower RF's Website in Appreciation of Their Support

Empower RF Systems - RF CafeEmpower RF Systems is a global leader in power amplifier solutions. Empower RF Systems is an established and technologically superior supplier of high power solid state RF & microwave amplifiers. Our offerings include modules, intelligent rack-mount amplifiers, and multi-function RF Power Amplifier solutions to 6 GHz in broadband and band specific designs. Output power combinations range from tens of watts to multi-kilowatts. Unprecedented size, weight and power reduction of our amplifiers is superior to anything in the market at similar frequencies and power levels.

Tuesday the 24th

For the Record - A Friend & Associate

For the Record - A Friend & Associate, September 1960 Electronics World - RF CafeI though this editorial from the September 1960 issue of Electronics World magazine was going to be a eulogy to some dearly departed electronics industry titan, but thankfully it was a changing-of-the-guard announcement. Those of you who have followed the many articles scanned and posted from my copies of vintage Electronics World are familiar with the name Oliver Read (Dr.) as having been the publication's editor for many years (22 in fact, per the article). W.A. Stockton took over Dr. Reads editorial duties when he retired from the position. Dr. Read was a ham radio enthusiast and formerly worked as a designer of amateur radio build-it-yourself kits. He was also one of the few people permitted to witness and report on the Bikini Atoll atom bomb test...

Public Service Announcement on Pfizer COVID-19 "Vaccine"

U.S. FDA Pfizer COVID-19 Vaccine EUA Extension - RF CafeContrary to what the president and others have said, the Pfizer mRNA shot was NOT approved by the FDA yesterday. The FDA issued a press release that said it was approved but all they did was to revise the Emergency Use Authorization (EUA). From page 2 of letter to Pfizer: "On August 23, 2021, having concluded that revising this EUA is appropriate to protect the public health or safety under section 564(g)(2) of the Act, FDA is reissuing the August 12, 2021 letter of authorization in its entirety with revisions incorporated to clarify that the EUA will remain in place for the Pfizer-BioNTech COVID-19 vaccine for the previously-authorized indication and uses, and to authorize use of COMIRNATY (COVID-19 Vaccine, mRNA) under this EUA for certain uses that are not included in the approved BLA." Page 12: " This product has not been approved or licensed by FDA, but has been authorized for emergency use by FDA, under an EUA to prevent Coronavirus Disease 2019 (COVID-19) for use in individuals 12 years of age and older."

Carl & Jerry: Ultrasonic Sound Waves

Carl & Jerry: Ultrasonic Sound Waves, July 1955 Popular Electronics - RF CafeAside from the storyline, one notable aspect of this installment of "Carl & Jerry" is one of the illustrations used in it. Jeff Duntemann (K7JPD), himself a sci-fi and technical book author, wrote a piece on the evolution of John T. Frye's Carl & Jerry series in Popular Electronics, and in it he commented on the changes in drawing styles and character appearances over the many years that Frye inked his illustrations. I read Duntemann's article a while ago, but remembered the picture of Norma and Carl's dog Roscoe when I saw it again just now. The format obviously departs from the vast majority of Frye's typical works due to its distinctly cartoonish look. As for the plot of the story...

Satellites a Surprisingly Great Option for IoT

Satellites a Surprisingly Great Option for IoT - RF Cafe"For many people, the phrase "Internet of Things" probably brings to mind either smart city efforts such as streetlamps with traffic cameras and air-quality sensors, or connected devices in their own homes. And a very natural question is, why would you ever want to use satellites to connect any of those devices? The answer is - you don't. It doesn't make sense to try. But the satellite-based IoT network industry is building steam nonetheless. Although in many ways it's like satellite broadband - itself a last resort for people who have no other connectivity options - IoT networks and satellites are, in some ways, a better match for each other. The Fraunhofer Institute for Integrated Circuits, for example, recently announced that its terrestrial IoT technology, mioty (massive IoT), could be easily used by satellites..."

2021 Top 50 Electronics Distributors List

2021 Top 50 Electronics Distributors List - RF CafeThe Source Today logistics website posted their "2021 Top 50 Electronics Distributors List." The date says May 26, but it just appeared. You will need to download a PDF file for full details about methodology, but as for ranking, Arrow Electronics took top honors. Most of the higher ranking companies will be familiar to anyone in the electronics field for a decade or more. Avnet and Future Electronics followed, and Digi−Key, my personal favorite, finished at #4 - not bad. Richardson Electronics is in the middle at #25, and bringing up the rear is Advantage Electric Supply. Evidently there was no list in 2020 due to Wuhan Flu issues, but the 2019 Top Electronics Distributors List had the top 3 in the same order. Digi−Key moved up by one this year.

PMI 6.0 to 18.0 GHz Low Noise Amplifier w/2 dB NF

Planar Monolithic Industries' (PMI) 6.0 to 18.0 GHz Low Noise AmplifierPlanar Monolithic Industries (PMI) introduces a 6.0 to 18.0 GHz low noise amplifier with a 2 dB noise figure, model number PE2-19-6G18G-1R6-16-12-SFF. PMI Model No. PE2-19-6G18G-1R6-16-12-SFF is a low noise amplifier which operates between 6.0 to 18.0 GHz. This LNA provides 19 dB of small signal gain while maintaining a low noise figure of only 2 dB. The P1dB output power of 15 dBm enables the LNA to function as a LO driver for balanced, I/Q or image reject mixers. This model also features I/O's that are DC blocked and internally matched to 50 ohms...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 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...

Many Thanks to Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

Monday the 23rd

Hallicrafters Radio TG-10-F Radio Keyer

Hallicrafters Radio TG-10-F Radio Keyer, October 1945 Radio-Craft - RF CafeInterestingly, when I searched for the Hallicrafters TG-10-F Radio Keyer, the first thing that came up was an eBay offering for a Gray Manufacturing Army Signal Corps "Keyer TG-10-F" Morse Code Practice Machine. Evidently more than one manufacturer was contracted to make the model. It looks like a tape record / playback machine, but it feeds a reel of paper strips with dots and dashes followed by straight lines forming letters and words. An optical reader encodes the audio signal for code practice students - up to 300 at a time using the built-in amplifier. Morse code was a primary mode of communication during World War II because the transmit and receive equipment was simple and reliable, and could perform acceptable in the presence of noise and weak signals. It also had the advantage of some level of privacy since most people could not understand code, especially when sent at high data rates (WPM). There does not seem to be a feed speed adjustment on the control panel... (see update on Technical Manual)

Thanks Again for Windfreak Technologies' Continued Support!

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

This Is What the E−Highway Looks Like?

This Is What the E−Highway Looks Like? - RF CafeI had to check my calendar to make sure this article wasn't posted on April 1st. Trolley Trucks are the future of long-haul transportation? Are they kidding? This is the Siemens eHighway concept. Installing thousands of miles of high voltage overhead lines might be less expensive and doable than burying induction coils in the road, but what happens when bad weather or terrorists take out a stretch of lines? It might be more practical than tearing up highways, but regardless of the configuration traffic will need to be interrupted during construction. Pity the Ham with an unloaded 1/4-wave whip antenna crossing under one of those arrangements!

Electronic Tube Schematic Symbols

Electronic Tube Schematic Symbols, August 1944, Radio-Craft - RF CafeYeah, you're right, almost nobody needs a chart of vacuum tube schematic symbols, but for the few nostalgic types who do, here is one from a 1944 edition of Radio-Craft magazine. As with schematic symbols for transistors, these renditions are representative of the general appearance you will find, but the exact manner in which tube symbols appear vary greatly. Perusing all the various electronics publications of the day will reveal many "standards." There are still many people around the world who service and restore vintage vacuum tube equipment...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Many Thanks to Axiom Test Equipment for Continued Support!

Axiom Test Equipment - RF CafeAxiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today!

Sunday the 22nd

Science Theme Crossword Puzzle for August 22nd

Science Theme Crossword Puzzle for August 22nd, 2021 - RF CafeThis Science Theme crossword puzzle for August 22nd, 2021, contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Many Thanks to ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 


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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