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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 typing 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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"Building a Heathkit was the electronics equivalent of painting a Rembrandt by the numbers." - Robert Lucky

Today in Science History

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Tech Industry Headlines - RF Cafe- Archive -

• Global 5G Smartphone Shipments Soar 458% YoY

• Chinas Pollution Exceeds Total Developed World's as of 2019

• Space Command to Launch Joint Cyber Center

• Broadcom's Henry Samueli Is Giving Away Billions

• Silver Lining for Extreme Electronics

• TIM Reportedly Says Arrivederci to Huawei

• Apple Takes Lead as 5G Smartphone Sales Boom

• GlobalFoundries Moving HQ to NY as It Expands Fab Capacity (must like high taxes)

RCA Victor Models 54Bx Radio Data Sheet

RCA Victor Models 54B1, 54B-N, 54B2, 54B3 Radio Data Sheet 335, May 1946, Radio-Craft - RF CafeSometimes finding an existing instance of one of the vintage radios is difficult or impossible. The RCA Victor Model 54Bx portables are an exception. Plenty can be found for purchase on eBay as this is written, as was a 54B1, 54B3, and a 54B4. I did a capture of some of the listing images for a Model 54B2, and had Archive.org story a copy for once the eBay site deletes it. In the internal photos, all four miniature vacuum tubes (3S4, 1S5, 1R5, 1T4) can be clearly seen. Note also in the photos you can see where, per the alignment procedure, rubber bands have been place around the tubes in order to keep them from moving. The extremely cramped space required particular attention to the routing of interconnect wires...

Electronic Assembly Technician Needed by Triad RF Systems

Electronic Assembly Technician Needed by Triad RF Systems - RF CafeTriad RF Systems is a fast-growing leader in the design and manufacture of RF power amplifiers and radio systems. We are looking for an experienced Electronic Assembly Technician to support our growth. This position will work in our Assembly Team under the direction of our Production Manager. Required skills and qualifications include assembles electronic components, assemblies, subassemblies, RF modules and systems with work orders and visual work instruction as directed by the Production Manager. Performs mechanical assembly operations while building electronic assemblies using standard measuring tools and techniques, performs electronic assembly operations such as wire termination, and installation...

Sangamo Electric Company

Sangamo Electric Company, May 1950 Radio & Television News - RF CafeRemember the Sunday comics feature for kids where there was a picture drawn with things wrong in it, and you had to find them all? This 1950 advertisement for the Sangamo Electric Company's line of capacitors, which appeared in Radio & Television News magazine, could server as a modern-day version for the Cancel Culture "woke" crowd that believes it has a duty to criticize and impugn everything it happens to fear, not like, or not understand. My list is at the bottom of the page if you want to compare it to yours. On other Sangamo ad post pages I have provided a bit of research on the background of "Samgamo" to try to determine whether the use of Native Americans (aka "indians" at the time) was based on a local tribe. No link has ever been found. Below the ad are a few of the items discovered...

Rainy Day Amusements, 1982 Old Farmer's Almanac

Rainy Day Amusements, 1982 Old Farmer's Almanac - RF CafeThe "Rainy Day Amusements" feature was not usually a mathematical challenge; for that, see the "Old & New Mathematical Puzzles" section. Some years they were worthwhile, end others not so much so. 1982 was a pretty good year for Rainy Day Amusements, so they are included here. Each autumn I used to anxiously await the appearance of the newest edition of The Old Farmer's Almanac on the store shelf, and such was the case with this 1982 issue. It is not that I was/am an avid farmer, just that I enjoy reading the anecdotes, tales, and interesting historical tidbits included amongst the pages along with tables of high and low tides, moon and sun rising and setting times...

CENOS Affordable Simulation Software for Antenna Design

CENOS Launches Affordable and Easy-to-Use Simulation Software for Antenna Design - RF CafeElectromagnetics simulation software company CENOS continues on its mission to democratize simulation software by releasing its newest application designed for radio frequency and antenna design engineers. After a year of development and testing in close cooperation with its avid beta-tester community, the Antenna Design simulation software was finally released for public use at the end of April, 2021. CENOS Antenna Design is an intuitive FEM-based software that helps engineers to speed up RF antenna design, it solves Maxwell’s equations directly with no simplifications or limitations. CENOS Antenna Design is free to try for 10 days, after which the users can choose from the two subscription plans - for an individual or business use, starting from €20/mo ($25/mo)...

Many Thanks to Berkeley Nucleonics for Continued Support!

Berkeley Nucleonics Corp - RF CafeBerkeley Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC initially developed custom pulse generators. We became known for meeting the most stringent requirements for high precision and stability, and for producing instruments of unsurpassed reliability and performance. We continue to maintain a leadership position as a developer of custom pulse, signal, light, and function generators. Our designs incorporate the latest innovations in software and hardware engineering, surface mount production, and automated testing procedures.

Origin of "HAM" for Amateur Radio Operators

Origin of the Name "HAM" for Amateur Radio Operators - RF CafeThis story was posted sometime around 2009. Since that time, research has been conducted by members of the Harvard Wireless Club regarding the veracity of the claim. RF Cafe visitor Fred Hopengarten, Esq. (K1VR), wrote to apprise me of the situation. It concludes as follows: "Back in 1999, the late K3UOC, who received his Ed.D. from the Harvard Graduate School of Education and was very active with our club, wrote: Note: This legend has been published and told by word-of-mouth countless times over the past 90 years. Unfortunately, it isn't so. HWC members researched this story, even obtaining the copy of the Congressional Record for the date in question. We could find no record of Mr. Hyman appearing before congress. We have to admit, though, it's a very entertaining story!"

New for 2021! RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils 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). Stencils 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...

Fundamental Crystal Control for Ultra-High Frequencies

Fundamental Crystal Control for Ultra-High Frequencies, April 1932 QST - RFCafeYou always need to pay careful attention to "breakthrough" type articles when they appear in April issues, since many magazines have a tradition of burying an "April Fools' Day" item without notice. This April 1932 issue of QST magazine seems to be legitimate. The term "lycopodium pattern" aroused my suspicion, but it turns out to refer to a pattern of vibration that resembles the needle orientation of certain pines and cedars. As radio frequencies continued to increase during the early years of "wireless" development, the use of quartz crystals as a stable reference source ran into a physical limitation because as crystal slices reached a certain thinness, overtone and subharmonics appeared that caused problems in circuits. A new mineral called tourmaline saved the day. With an elasticity much greater than quartz, tourmaline is able to vibrate at higher fundamental frequencies for a given thickness...

Senior RF Engineer Wanted by Triad RF Systems

Senior RF Engineer Wanted by Triad RF Systems - RF CafeTriad RF Systems is a fast-growing leader in the design and manufacture of RF power amplifiers, bidirectional amplifiers, and RF systems. We are looking for a Senior RF Design Engineer to join our team in New Jersey. The Senior RF Design Engineer will lead the development of new SSPA and transmit / receive products for our rapidly expanding catalog and customer base. Required skills and qualifications include Bachelor's degree in Electrical Engineering or equivalent related experience, minimum 5 years professional experience in RF engineering, experience with the simulation, design, test, and realization of RF power amplifiers and low noise receiver front-ends operating up through C Band, SSPA design knowledge or experience up to 50 W...

Exodus Intros 1-2 GHz, 4 kW SS Pulse Amplifier

Exodus Advanced Communications Intros 1-2 GHz, 4 kW Solid State Pulse Amplifier - RF CafeExodus Advanced Communications' AMP2043P-4KW Solid State Pulse Amplifier (1.0-2.0 GHz, 4 kW Pulse) is designed for Pulse/HIRF Mil-Std 461/464 and Radar applications. Other frequency ranges & power levels available all providing Superb Pulse Fidelity. Up to 100 μsec pulse widths, 6% duty cycles and 66 dB gain. Available monitoring parameters for Forward/Reflected power, VSWR, voltage, current, temperature sensing for outstanding reliability and ruggedness in a 10U chassis. Features Small form factor rack-mounted system, Class AB linear advanced technology design, instantaneous L-Band octave bandwidth, linear high peak pulse applications, designed for EMI/RFI, lab, HiRF/pulse applications...

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.

Electronics-Themed Comics: Radio Term Illustrated

Electronics-Themed Comics: Radio Term Illustrated, April and May 1946, Radio-Craft - RF CafeHere is another trio of vintage electronics-themed comics from Radio-Craft magazine. Two are part of illustrator Frank Beaven's "Radio Terms Illustrated" series, where readers would write in with suggestions and Mr. Beaven would put the ideas in ink. These two are "Poor Reception, and "Regeneration." If you look at the bottom of the page, you will find a big listing of other comics, with many of the other "Radio Terms Illustrated" instances ("High Potential," "Signal Generator," "Overload Capacity," "Amplitude," "Transmission Loss," etc.) labeled. Enjoy!

Mathematical Puzzles, 1982 Old Farmer's Almanac

Mathematical Puzzles, 1982 Old Farmer's Almanac - RF CafeEach autumn I used to anxiously await the appearance of the newest edition of The Old Farmer's Almanac on the store shelf, and such was the case with this 1982 issue. It is not that I was/am an avid farmer, just that I enjoy reading the anecdotes, tales, and interesting historical tidbits included amongst the pages along with tables of high and low tides, moon and sun rising and setting times, astronomical events, and weather patterns expected for the year that lay ahead. Most of all, I liked working the puzzles and riddles. Over the years the difficulty levels gradually got lower and lower (aka dumbed down), to the point where for the last decade or so I have not even bothered buying the OFA. Now it is full of numbnut stuff. Because quite a few of the Mathematical Puzzles from the older editions are worthy of an engineer's cerebratio

Webinar: Pulse Stability Measurement of Radar Signals

Webinar: Pulse Stability Measurement of Radar Signals - RF CafeRohde & Schwarz has produced a webinar entitled "Pulse Stability Measurement of Radar Signals," which is available for viewing on their website. They appreciate your registering, but if for some reason it doesn't work, click on the thumbnail above to go directly to it. "With the arrival of sophisticated radar and communication systems, phase noise has become the most important factor engineers focus on during the design and validation phase. Phase stability is the key parameter for defining target acquisition in radars, spectral integrity in communication systems and precision beam steering capabilities in active electronic scanned array antennas (AESA)..."

The Conical Monopole Antenna

The Conical Monopole Antenna, November 1966 QST - RF CafeIt is important to concentrate your transmitter power into the proper beam if you wish to deliver the best signal to the other fellow's receiving antenna. This has logically led to the popularity of the Yagi beam antenna on the higher-frequency amateur bands. A beam antenna for the 80-meter band should have a 140-foot reflector and a 77-foot boom on a 250-foot tower. This makes the beam antenna impractical for the 80-meter band, and even for 40-meter operation a full-size Yagi is a forbidding structure to the neighbor's narrow-minded view - even a well-trained XYL might view such a monster beam with alarm. There is no easy solution to the need for a good DX antenna at low frequency, but the conical monopole antenna may be of interest to the more eager radio amateur as a more practical solution. The conical monopole antenna is a base-fed vertical antenna that has an omni-directional pattern in azimuth but with an elevation...

Axiom Blog: Test Equipment Are Investments in Low Carbon Footprint

Axiom Blog: Test Equipment Are Investments in Low Carbon Footprint - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company, has published a new blog post that aims at informing people about the importance of carbon neutrality and about the different test equipment that support it with the help of regenerative energy. It suggests a thinking-out-of-the-box approach regarding how "test applications can strive for low carbon footprints by characterizing the quality of a device under test (DUT) that supports carbon neutrality, such as regenerative energy in an EV's charging system. Efficient use of energy is possible by feeding power generated by a DUT during the measurements back to the power grid, rather than dissipating the energy as heat lost to the environment." On a single DUT (Device Under Test) basis that might seem insignificant, but when hundreds of millions of vehicles are being tested of time, the energy saved can be enormous...

Many Thanks to Exodus Advanced Communications for Their Support

Exodus Advanced Communications - RF CafeExodus Advanced Communications is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. Power amplifiers ranging from 10 kHz to 51 GHz with various output power levels and noise figure ranges, we fully support custom designs and manufacturing requirements for both small and large volume levels. decades of combined experience in the RF field for numerous applications including military jamming, communications, radar, EMI/EMC and various commercial projects with all designing and manufacturing of our HPA, MPA, and LNA products in-house.

The RCA Antennalyzer

The RCA Antennalyzer, May 1946, Radio-Craft - RF CafeIt is little wonder that advancements in technology, mathematics, finance, medicine, chemistry, and other disciplines requiring massive numerical computation began accelerating at a rapid pace following the invention of computers. The mechanical computers of Blaise Pascal and Charles Babbage were some of the earliest attempts to make laborious, repetitious calculations faster and less error prone, and they quickly led to many other types of general- and special-purpose machines that by the mid-twentieth century were calculating ballistic flight paths, astronomical positions, electrical circuit functions, probabilities, and other quantities. Programmable electronics computers like the ENIAC greatly enhanced the ability to apply mathematics to just about any problem. However, even by the early Apollo era the government and private institutions employed teams of human calculators to crank out large volumes of tabular data...

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