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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 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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Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe- Archive -

• Severe Degradation to Wi-Fi in Presence of Licensed Assisted Access (LAA)

• Car Connectivity Consortium Releases CCC Digital Key 3.0 Spec

• Highly Efficient Supercapacitor Could Rival Batteries

• Israel Pushes Military Digital Transformation

• AO-109 (RadFxSat-2/AMSAT Fox-1E) Open for Amateur Use

• Ericsson Loses Share, Nokia Secures China Mobile 5G Win

• FCC Investigating Alleged Jamming on 40 Meters

• Supply-Chain Innovation Can Bolster U.S. Security  

• Google's Quantum Computer Exponentially Suppresses Errors

Name-the-Scientist Crossword Puzzle

Name-the-Scientist Crossword Puzzle, September 1960 Electronics World - RF CafeHere is another of John Comstock's crossword puzzles from a 1960s issue of Electronics World magazine. His "Name-the-Scientist" puzzle, as the title suggests, draws mostly on your knowledge of men who are very familiar to anyone who has been in the electronics game for a while. There are a few not-a-name words, but they are related to somebody's name. Mr. Comstock must have been really fond of one guy since he and his invention appear multiple times in various forms. I have to admit to missing 17 Down, but then at least recognizing the name after seeing it in the answer key.

Trending Space-Qualified RF Components

Trending Space-Qualified RF Components in 2021 - RF Cafe"Electronic components face a host of challenges while in space, from extreme temperature variation to space radiations. These harsh conditions mean that any Commercial Off-the-Shelf (COTS) component cannot be used for space missions. The electronic components used in making satellites must be able to withstand a wide range of environmental challenges - from the complexities of being launched from Earth to the extremely harsh environment of outer space. everything RF has compiled a list of 10 trending space-qualified RF components. Visit the new SPACE HUB on everything RF to keep up to date with the latest on space-qualified components..."

Magnetic Properties of Tape

Magnetic Properties of Tape, August 1967 Electronics World - RF CafeIf you are a collector of vintage high-end audio equipment, chances are you owned a reel-to-reel tape player. I remember back in the 1970s that anybody wanting to call himself an audiophile had better own a rack-mounted reel-to-reel player. Of course the funny part is that many of those people could not afford to buy original recordings on tape, so they would dub from an LP on a turntable or from a cassette or, gasp, 8-track tape. This article from the August 1967 edition of Electronics World delves into the technical aspects of magnetic tape, daring to introduce such terms as intrinsic cohesive force, residual induction, and flux - heavy stuff for the layman. Of course, regurgitating such terms while wowing (pun intended) their friends with a rolling tape held to keep the subject off of whether the music being played on a $1000 reel-to-reel player had been dubbed from a $75 cassette deck...

Waveguide Theory and Application - Signal Coupling

Waveguide Theory and Applications: Signal Coupling (NEETS), Module 11 - RF CafeWhen less efficient coupling is desired, you can rotate or move the loop until it encircles a smaller number of H lines. When the diameter of the loop is increased, its power-handling capability also increases. The bandwidth can be increased by increasing the size of the wire used to make the loop. When a loop is introduced into a waveguide in which an H field is present, a current is induced in the loop. When this condition exists, energy is removed from the waveguide. Figure 1-40A - Loop coupling in a rectangular waveguide. Slots or apertures are sometimes used when very loose (inefficient) coupling is desired, as shown in figure 1-41. In this method energy enters through a small slot in the waveguide and the E field expands into the waveguide. The E lines expand first across the slot and then across the interior of the waveguide. Minimum reflections occur when energy is injected or removed if the size of the slot is properly proportioned to the frequency of the energy...

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...

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.

90-Mile Laboratory for Telephone and Television

Bell Telephone Laboratories, June 1945 Radio News - RF CafeHere is yet another report on the work done by Bell Telephone Laboratories to advance the science of telecommunications. By 1945 when this appeared in Radio News magazine, Bell Labs had already been experimenting with coaxial cable as a means of transmission for broadband voice, facsimile, and video signals. In fact, it claims coax was used as early as 1927 to connect New York City to Washington, D.C., and that a new loopback system simulating a 3,800-mile run was being tested between New York City and Philadelphia. Microwave relay stations* were also in their infancy at the time, so investigations into both modes of long distance transmission were being explored. It is too bad the company got overzealous and abused the customers who funded their success, resulting in a court-ordered breakup of the monopoly in 1974. Of course company managers and lawyers quickly figured out a way to restructure the "Baby Bells" in a manner which, taken in totality...

Ultralight Material Withstands Supersonic Microparticle Impacts

Ultralight Material Withstands Supersonic Microparticle Impacts - RF Cafe"A new study by engineers at MIT, Caltech, and ETH Zürich shows that 'nanoarchitected' materials - materials designed from precisely patterned nanoscale structures - may be a promising route to lightweight armor, protective coatings, blast shields, and other impact-resistant materials. The researchers have fabricated an ultralight material made from nanometer-scale carbon struts that give the material toughness and mechanical robustness. The team tested the material's resilience by shooting it with microparticles at supersonic speeds, and found that the material, which is thinner than the width of a human hair, prevented the miniature projectiles from tearing through it..."

Crosley Scraps '43 Line for Military Radios

Crosley Scraps '43 Line for Military Radios, September 1942 Radio-Craft - RF CafeThere was a time when we did not take the availability and abundance of everything for granted. Most of us have parents or grandparents who were around during World War II that can tell stories of ration stamps for certain food and clothing items, fuel, tires, and other things. I have a few given to me by my grandfather. Many industries, including electronics manufacturing, were strongly encouraged or required to dedicate all efforts toward war production. Crosley Corporation, based in Cincinnati, Ohio, was no exception. A notice of Crosley abandoning their 1943 line of commercial radios to make way for military radios appeared in the September 1942 edition of Radio-Craft magazine. This is of particular interest to me since I just completed the restoration of a 1941 vintage Crosley 03CB floor console radio. It means I probably have one of the last pre-war models of a Crosley radio...

ARCTURUS Ultra-Compact 5G FPC Antenna

ARCTURUS Ultra-Compact 5G FPC Antenna - RF CafeARCTURUS is the new flexible antenna for 5G/4G LTE/3G/2G/NB-IoT/CATM applications designed by Synzen Precision Technology. In today's tech and electronics world, where the modern mantra is to think bigger and make smaller, we've designed perhaps the most compact and versatile 5G FPC antenna on the market. Measuring just 88 mm x 14 mm, ARCTURUS can be placed internally in devices which require an integrated antenna solution. Its ultra-small form factor doesn't compromise on performance, covering a hugely impressive array of wideband frequencies from 617-5000 MHz. Arcturus can be easily integrated with its "peel and stick" self-adhesive backing...

Microwave Principles: Waveguide Theory and Application

NEETS Module 11 Microwave Principles: Waveguide Theory and Application - RF CafeThe velocity of propagation of a wave along a waveguide is less than its velocity through free space (speed of light). This lower velocity is caused by the zigzag path taken by the wavefront. The forward-progress velocity of the wavefront in a waveguide is called Group Velocity and is somewhat slower than the speed of light. The group velocity of energy in a waveguide is determined by the reflection angle of the wavefronts off the "b" walls. The reflection angle is determined by the frequency of the input energy. This basic principle is illustrated in figures 1-28A, 1-28B, and 1-28C. As frequency is decreased, the reflection angle decreases causing the group velocity to decrease. The opposite is also true; increasing frequency increases the group velocity. The waveguide analyzed in the previous paragraphs yields an electric field configuration known as the half-sine electric distribution...

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 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.

Postwar Plans for the Radio Dealer

Postwar Plans for the Radio Dealer, June 1945 Radio News - RF CafeBy June of 1945 when this "Postwar Plans for the Radio Dealer" article appeared in Radio News magazine, Germany had unconditionally surrendered at Reims, France. Japan was still holding out for an unlikely victory and prepared for a massive Allied landing on their homeland with the likely loss of millions of souls, but most people could feel that the end of World War II was imminent. Accordingly, trade magazines of the day ran many pieces discussing potential options for out-of-work servicemen. Vast amounts of knowledge and experience had been gained in the previous half a decade, and it was to be put to good use. Lots of men left their jobs and businesses behind for the sake of saving the free world, and were anxious to pick up...

Radio Signals Used to Develop Images of Hidden Objects

NIST Uses Radio Signals to Develop Images Hidden Objects - RF Cafe"Researchers at the National Institute of Standards and Technology (NIST) and Wavsens have developed a method for using radio signals to create real-time images and videos of hidden and moving objects, which could help firefighters find escape routes or victims inside buildings filled with fire and smoke. The technique could also help track hypersonic objects such as missiles and space debris. The new method, described June 25 in Nature Communications, could provide critical information to help reduce deaths and injuries. Locating and tracking first responders indoors is a prime goal for the public safety community. Hundreds of thousands of pieces of orbiting space junk are considered dangerous to humans and spacecraft..."

Waveguide Theory and Application (NEETS)

Waveguide Theory and Application (NEETS), Module 11 - RF CafeThat portion of the electromagnetic spectrum which falls between 1000 megahertz and 100,000 megahertz is referred to as the Microwave region. Before discussing the principles and applications of microwave frequencies, the meaning of the term microwave as it is used in this module must be established. On the surface, the definition of a microwave would appear to be simple because, in electronics, the prefix "micro" normally means a millionth part of a unit. Micro also means small, which is a relative term, and it is used in that sense in this module. Microwave is a term loosely applied to identify electromagnetic waves above 1000 megahertz in frequency because of the short physical wavelengths of these frequencies. Short wavelength energy offers distinct advantages in many applications...

Stratospheric Balloons for Monitoring and Surveillance

Stratospheric Balloons for Monitoring and Surveillance - RF Cafe"These eyes in the sky fly above drones and below satellites. Alphabet's enthusiasm for balloons deflated earlier this year, when it announced that its high-altitude Internet company, Loon, could not become commercially viable. But while the stratosphere might not be a great place to put a cellphone tower, it could be the sweet spot for cameras, argue a host of high-tech startups. The market for Earth-observation services from satellites is expected to top US $4B by 2025, as orbiting cameras, radars, and other devices monitor crops, assess infrastructure, and detect greenhouse gas emissions. Low altitude observations from drones could be worth. Balloons in the stratosphere, 20 kilometers above Earth (and 10 km above most jets), split the difference..."

Introduction to Circuit Protection, Control, and Measurement - Multimeters

Introduction to Circuit Protection, Control, and Measurement (NEETS) - RF CafeBy adding several shunt resistors in the meter case, with a switch to select the desired resistor, the ammeter will be capable of measuring several different maximum current readings or ranges. Most meter movements in use today have sensitivities of from 5 microamperes to 1 milliampere. Figure 1-22 shows the circuit of meter switched to higher ranges, the shunt an ammeter that uses a meter movement with a sensitivity of 100 microamperes and shunt resistors. This ammeter has five ranges (100 microamperes; 1, 10, and 100 milliamperes; 1 ampere) selected by a switch. With the switch in the 100 microampere position, all the current being measured will go through the meter movement. None of the current will go through any of the shunt resistors...

Base-Insulating Your Vertical

Base-Insulating Your Vertical, December 1962 Popular Electronics - RF CafeAs with just about every other type of hobby anymore, creativity and mechanical aptitude is not much of a necessity if you have money to spend. There is such a plethora of options available for every conceivable need to satisfy whatever degree of complexity you want your hobby to entail. The back third of every edition of the ARRL's QST magazine is loaded with advertisements offering antennas, radios, towers, test equipment, guy wires, insulators, cables, connectors, soldering stations, semiconductors, tubes, nuts and bolts. It is a wonderful world we live in if your desire is to engage in the operational aspect of a hobby rather than the building and experimenting aspects. It was not always so. Half a century ago the average hobbyist needed to scrounge for components that could be "repurposed" for use as needed. Sure, there were many sources for common components then, but even if they were available, hobbyists either could not afford them...

Radio Theme Crossword Puzzle for July 25th

Radio Theme Crossword Puzzle for July 25th, 2021 - RF CafeThis Radio Theme Crossword Puzzle for July 25th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. 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., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy --- This one is going to take a while!

TotalTemp Technologies (Thermal Platforms) - RF Cafe
Werbel Microwave - RF Cafe
LOTUS Communications Systems Modular RF Component Building Blocks - RF Cafe

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