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Homepage Archive - August 2022 (page 1)

See Page 1 | 2 | 3 | 4 | 5 of the August 2022 homepage archives.

Sunday the 7th

Science Themed Crossword Puzzle for August 7th

Science Themed Crossword Puzzle for August 7th, 2022 - RF CafeHere is your custom made Science Themed Crossword Puzzle for August 7th, 2022. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only 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!

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF 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...

Please Thank RF Superstore for Their Continued Support

RF Superstore coaxial cable, connectors, adapters - RF CafeRF Superstore launched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $25. We're leading the way again!

Friday the 5th

Electronics-Themed Comics

Electronics-Themed Comics, July 1952 Radio-Electronics - RF CafeAs I often do on Fridays, I searched through my collection of vintage electronics magazines for some tech-themed comics. This group of five appeared in the July 1952 issue of Radio-Electronics. A couple of these were suggested by the magazine's readers, and staff artists turn the ideas into drawings. The Standing Waves comics gets my vote for the best of the lot for cleverness. Page 102's comic could be (almost) a depiction of a contemporary in-home entertainment center, given the size of televisions today. For some reason I'm not "getting" the gag in the page 113 comic, which features a buxom woman with big hair doing a juggling act on TV...

Algorithm Aces University Math Course Questions

Algorithm Aces University Math Course Questions - RF CafeI have to admit to being drawn to this story primarily due to the graphic. Although it does not appear on an RF website, there is a Smith chart and reflection coefficient equations included. I also like the striated blue motif. "Multivariable calculus, differential equations, linear algebra - topics that many MIT students can ace without breaking a sweat - have consistently stumped machine learning models. The best models have only been able to answer elementary or high school-level math questions, and they don't always find the correct solutions. Now, a multidisciplinary team of researchers from MIT and elsewhere, led by Iddo Drori, a lecturer in the MIT Department of Electrical Engineering and Computer Science (EECS), has used a neural network model to solve university-level math problems in a few seconds at a human level. The model also automatically explains solutions and rapidly generates new problems in university math subjects. When the researchers showed these machine-generated questions to university students, the students were unable to tell..."

Crosley Model 56TD-W Schematic & Parts List

Crosley Model 56TD-W Schematic & Parts List, November 1947 Radio News - RF CafeThese are the schematics and parts list for vintage Crosley model 56TD-W vacuum tube radio, as it appeared in the November 1947 issue of Radio News magazine. I scan and post these for the benefit of hobbyists and historians seeking such information. As time goes by, there is less and less likelihood that records of these relics from yesteryear's archives will be made available. As with all historical information, it takes someone with a personal interest in preserving the memories in order to fulfill the mission, and I am glad to be a small part of that cadre. Also, I found a short video (below) from someone who did an excellent job restoring a Crosley Model 56TD Duette tabletop radio...

Atek Midas Added to Vendor Pages

Atek Midas Added to Vendor PagesAtek Midas, based in Istanbul, Turkey, is a technology company working on high-frequency integrated circuit (RFIC/MMIC) products as its roadmap. Their main target markets are satellite communication, telecommunications, test & measurement and aerospace & defense. Atek Midas has been added to my collection of Vendor pages in the categories of RFIC/MMIC's, attenuators, power and low noise amplifiers, mixers, power dividers, filters, RF front ends. Please check out their website to see if they can help you with your project...

Checking Beam Antennas with the S-Meter

Checking Beam Antennas with the S-Meter, April 1939 QST - RF CafeAntenna radiation (beam) patterns published by manufacturers are obtained under ideal - or close to ideal - conditions with a carefully prepared and calibrated open air test site (OATS) or an enclosed anechoic chamber. Multipath, imperfect earth ground, obstacles both manmade and natural, misshapen elements, poor VSWR, antenna orientation (in both azimuth and elevation) are among the many factors which produce real-world operational results that do not jive with a manufacturer's datasheet. Without employing some far field 3-dimensional field strength scheme (see Drone-Based Field Measurement System™), there is no way to obtain a complete picture of how your antenna performs in all directions. This article presents a practical procedure for making measurements that will at least collect useful data for specific orientations...

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 stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF Cafe

Reactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Thursday the 4th

The SCR Revolution

The SCR Revolution, February 1966 Electronics World - RF CafePrior to the invention of the silicon-controlled rectifier (SCR), most semiconductor devices were only able to handle powers in milliwatt range, with some reaching into the realm of a few watts or tens of watts. Voltage handling got up to around 1 kV (and 500 A) for diodes and 200 V for transistors. The higher power and voltage devices were exceedingly expensive and were used primarily in special applications. When this article appeared in a 1966 issue of Electronics World magazine and the SCR had been introduced less than a decade earlier, the price of an SCR had dropped from more than $300 to less that 50¢ apiece. Due to the construction of the SCR, it is more robust and can handle high power switching applications (it is generally not used as a signal amplifier). Unlike a triac, which can be controlled with a signal to turn the device both on and off while voltage is present across the anode and cathode, the SCR can only be used to switch off current...

Mac's Radio Service Shop: Safety in Servicing

Mac's Radio Service Shop: Safety in Servicing, January 1954 Radio & Television News - RF CafeIt's time to gather 'round for another story about fictional radio service shop owner Mac McGregor and his trusted sidekick technician, Barney. In this January 1954 Radio & Television News episode, an errantly wired bypass capacitor on a chassis from one of the old AC/DC radio sets caused Mac to get a 300-volt wakeup call when his hand brushed against it. After explaining the situation to Barney and apprising him of the danger it poses to an owner who unwittingly sticks his/her hand into the back of the cabinet, Mac lists a few other common dangers to watch for. Radios that ran on either AC or DC power were very common back in the early days because there were homes and businesses that had both type systems wired in to the premises - in part due to the famous battle between Thomas Edison's preferred DC electrical distribution system and Nikola Tesla's preferred AC electrical distribution system. Another reason for DC compatibility was that prior to the Rural Electrification Act of 1936, many homes not located in cities and nearby suburbs had no electric service at all. Farm homes often ran on DC power supplied by banks of lead-acid storage batteries, with wind- or water-powered generators providing the charging current. Radios, aka "wireless sets," were powered by those batteries. In order to accommodate both AC and DC supplies, radio designers conjured up power supply circuits...

Cubic Boron Arsenide Best Semiconductor Ever?

Cubic Boron Arsenide Best Semiconductor Ever? - RF Cafe"Silicon is one of the most abundant elements on Earth, and in its pure form the material has become the foundation of much of modern technology, from solar cells to computer chips. But silicon's properties as a semiconductor are far from ideal. For one thing, although silicon lets electrons whizz through its structure easily, it is much less accommodating to "holes" - electrons' positively charged counterparts - and harnessing both is important for some kinds of chips. What's more, silicon is not very good at conducting heat, which is why overheating issues and expensive cooling systems are common in computers. Now, a team of researchers at MIT, the University of Houston, and other institutions has carried out experiments showing that a material known as cubic boron arsenide overcomes both of these limitations. It provides high mobility to both electrons and holes, and has excellent thermal conductivity..."

Modular Test Solution Speed Semiconductor Testing

Axiom Test Equipment Blog: Modular Test Solution Speed Semiconductor Testing - RF CafeAxiom Test Equipment, Inc., an electronic test equipment rental and sales company has published a new blog post entitled "Modular Test Solution Speed Semiconductor Testing," explains how to pick the right module when you need a solution with semiconductor testing. A well-designed mainframe that operates according to plug-in modules can not only pack a great deal of measurement power into a small space, but it can also be configured as needed by exchanging modules. Modular semiconductor parameter testers are capable of top-line mainframe accuracy along with the test speed and flexibility for high-volume production-line device testing. Modular units provide a more "compressed" approach to executing semiconductor parameter measurements. A modular unit consists...

Ken-Rad Radio Tubes

Ken-Rad Radio Tube Advertisement, April 1947 Radio News - RF CafeAchieving what we consider relatively simple results with electronics indicators used to be cutting edge technology. This 6AL7-GT Electron-Ray Indicator Tube by Ken-Rad (a division of General Electric) provided a dual-channel electrofluorescent (i.e., cathode ray) display of relative signal strength or tuning the new-fangled FM radio stations. It was promoted in this 1947 issue of Radio News magazine. The tube could also be used, of course, for many other applications where signal strength from any measured process: fuel level, voltage, temperature, stock price, phase angle, sound volume, speed, etc., needed to be measured. Today, we have electrochemical indicators so cheap that they are built into off-the-shelf batteries at Walmart...

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 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.

Wednesday the 3rd

Pedro and the Incentive Plan

Pedro and the Incentive Plan, March 1952 Radio-Electronics - RF CafeThis is a pretty good electronics-related detective story. Admittedly, it did not turn out the way I expected, which is a good thing because the unexpected curve it threw me caused me to like the adventure even more. The author is Guy Slaughter, but it could have easily been one of John T. Frye's "Carl & Jerry" techno-adventures. I say that because (without giving away the ending) the sleuthing "good guy" uses his electronics communications savvy to solve the crime, the way Carl and Jerry are famous for doing. The setting is the early 1950s when electronics repair shops were commonplace and some customers did their best to swindle the proprietors out of honestly earned money - and sometimes products. Guy Slaughter wrote earlier pieces featuring Pedro for Radio-Electronics magazine...

Planck Quantities Explained

Planck Quantities Explained (Astronomy September 2022) - RF CafeIn the "Astro Letters" section of the September 2022 issue of Astronomy magazine, a reader wrote to ask why Planck mass uses units of 10-5 grams, while the other two Planck-scale constants (length at 10-33 cm and time at 10-44 s) are many orders of magnitude smaller. Stan Odenwald responded: "Using only the three natural constants - the speed of light (c=3x108 m/s), Newton's gravitational constant (G=6.67x10-11 m3/kg s2), and Planck's constant (h=6.6x10-34 m2 kg/s) - you can create three 'fundamental scales': length = (hG/c3)½, time = (hG/c5)½, and mass = (hG/c)½. But these scales are experimentally inaccessible. Although the Planck mass appears reachable (i.e., larger than the other quantities), it actually represents an energy of 1019 gigaelectronvolts crammed into a Planck-scale volume, which cannot be replaced by humans (yet). By comparison, the Large Hadron Collider at CERN achieves only 104 GeV in a volume of space 1010 time larger then the Planck scale." I'd like to be able to answer a question like that!

Telecan Robot: A Unique Attention Getter

Telecan Robot: A Unique Attention Getter, June July 1940 National Radio News - RF CafeExcept for a few notable examples such as the incredibly life-like humanoid robots coming from Japan, the overwhelming majority of robots today are either educational tools, special function equipment for performing highly precise tasks (surgical, exploratory, search & rescue), or part of high volume production lines. Back in 1940 when this "Telecan" robot debuted and appeared in National Radio News magazine, people though of robots almost exclusively as autonomous devices that would some day make life easier for the human race... or eventually conquer and subdue the human race into slavery. Constraining robots to the relatively inefficient layout and proportions of homo sapiens, as engineers have discovered, greatly limits their utility...

Antenna Design Considerations for 5G

Antenna Design Considerations for 5G - RF CafeMaurizio Di Paolo Emilio has an article on the EE|Times website entitled ,"Antenna Design Considerations for 5G Applications," which discusses some of the issues needed to be addressed for mobile hardware, namely multiple frequency bands and increased bandwidth. He begins, "A 5G mobile device's antenna design needs specific consideration to maintain performance. The entire performance is impacted by the ground plane, the antenna positioning on the board, and other associated components. The reliability needed by wireless devices is made possible by analyzing and making corrections from the very beginning of design. In order for smartphones to function well over a wider variety of RF frequency bands and support the transition to 5G and other technologies, tuning the aperture of an antenna is crucial. To accommodate expanding RF needs such as the usage of multiple input, multiple output (MIMO), and carrier aggregation (CA) methods..."

Emerson Models 507, 509, 518, 522 Radio Data Sheet

Emerson Models 507, 509, 518, 522, 535 Chassis Model 120005, September 1947 Radio News - RF CafeFor many years I have scanned and posted schematics & parts lists like this one featuring the Emerson models 507, 509, 518, 522, 535 Chassis Model 120005. An image of the page is included which, depending on the issue, might include a schematic, parts list, and tuning and service information. If there is extensive text, I run OCR on the scanned page and place it on the page to aid search engines. In this case, the September 1947 edition of Radio News contained only the schematic and parts list. A lot of these radios can be purchased on eBay. The Radio Museum and Radio Attic websites have some additional information. In fact, the image to the left is from a recent sale there. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. A running list of all data sheets posted thus far is at the bottom of the page...

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 Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF Cafe ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using gallium nitride (GaN), gallium arsenide (GaAs) and silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz.

Tuesday the 2nd

Bell Telephone Labs Sugar Scoop Antenna

Bell Telephone Labs Sugar Scoop Antenna, November 1959 Radio-Electronics - RF CafeLittle did the engineers depicted in this Bell Telephone Laboratories advertisement in a 1959 issue of Radio-Electronics magazine know the significance the "Sugar Scoop Antenna" they were erecting at the time would play in the world of astrophysics. Their intention, following the recently completed International Geophysical Year (IGY) efforts, was to design and build a system for characterizing the Earth's atmosphere in preparation for satellite communications. A cutting-edge, cryogenically-cooled ruby-based maser amplifier operated in the 5,600 MHz realm with thermal noise in the 18K region. Undoubtedly lots of good information was gleaned, but the most notable result from that antenna was the discovery in 1964 of the Cosmic Microwave Background (CMB) radiation by Bell scientists Drs. Robert W. Wilson and Arno A. Penzias. The pair was surveying the sky in the microwave spectrum and noticed that regardless of where the antenna was pointed, there was always a fairly constant level of "noise" that could not be removed from the system. It occurred to them that they had stumbled upon the very electromagnetic signature of the early post Big Bang universe. The rest, as the saying goes, is history...

Please Welcome Wireless Telecom Group as an RF Cafe Sponsor!

Wireless Telecom Group (RF power and noise measurement) - RF CafeThe Wireless Telecom Group, comprised of Boonton, CommAgility, Holzworth, and Noisecom, is a global designer and manufacturer of advanced RF and microwave components, modules, systems, and instruments. Serving the wireless, telecommunication, satellite, military, aerospace, semiconductor and medical industries, Wireless Telecom Group products enable innovation across a wide range of traditional and emerging wireless technologies. A unique set of high-performance products including peak power meters, signal generators, phase noise analyzers, signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable noise generators.

Using a VNA Like a Time-Domain Reflectometer

Using a VNA Like a Time-Domain Reflectometer - RF CafeAn interesting article entitled "Using a VNA Like a Time-Domain Reflectometer" is currently posted on the Microwaves & RF website. Author Roger Denker begins: "While VNA network measurements in the frequency domain help optimize or verify implementation of devices and components, time-domain measurements are effective for analyzing network geometry and specific sections of a network. Time-domain reflectometry (TDR) is a technique that measures and displays the impedance of a network (cable, filter, and so on) over time. Traditionally, this is done with a device that generates very fast pulses, injects them on the network, and measures the time and amplitude of reflected pulses. TDR yields information about the impedance as a function of the time it takes for a pulse to reflect or travel through the medium. And, because the signals travel with (nearly) the speed of light, the time can be translated to a distance through a cable or network..."

Pickett N1010-ES Slide Rule Classroom Demonstrator

Pickett N1010-ES Trig Slide Rule Classroom Demonstrator (Michael Maguire) - RF CafeMichael Maguire proudly shows his Pickett Model N1010-ES Trig Classroom Demonstrator. He picked it up at a garage sale for $20 - an fine example of being in the right place at the right time! It appears to be in excellent condition. The sliding cursor was missing, so he had one made. The "ES" (Eye Saver) designation refers to the black markings on a yellow background. Pickett produced many versions of the N1010 including this "Trig," the "Duplex," the "Trig Duplex," "Power Trig," the "Transitional," and the "Super Power Trig." There were pre-Eye Saver models of most of these as well...

Finding Your Way in Space

Finding Your Way in Space, May 1958 Popular Electronics - RF CafeJust as today's generation of engineering students grew up with and are totally accustomed to and proficient at using computers, smartphones, positioning devices, CAE software, and various combinations of the aforementioned, so have the latest cadre of pilots grown up with GPS and electronic flight charts and planners in the cockpit. The difference is that whereas engineering students are not still required to learn to use a slide rule and a drafting table to earn an engineering degree, pilots are still required to learn to navigate using primitive (not meant derisively) instruments and ground-based navaids to earn a pilot's license. That's not a bad thing, though, because whereas if your graphing, 2500-function calculator quits working, the only thing at risk is your test score if you happen to be taking an exam. However, if your electronic navigation fails while in a limited visibility environment or in controlled airspace, you had better be able to do some seat-of-the-pants flying or you could be in deep doo-doo. This 1958 article from Popular Electronics magazine presents the newfangled TACAN (TACtical Air Navigation) and Loran (LOng RAnge Navigation) systems recently introduced (at the time) by the CAA (Civil Aeronautics Authority), which is now...

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 stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

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.

Monday the 1st

Radio Controlled Model Sailboat

Radio Controlled Model Sailboat, April 1948 Radio News - Airplanes and RocketsAs you can tell from all the vintage modeling and electronics magazine I own and use to post various article, I am prone to waxing nostalgic about the days of yore. Being born in 1958, I am part of the last generation of people brought up at a time when patriotism, courtesy, manners, and civility was taught in school and in the public square by fellow citizens and even politicians. However, there are limits to my desire to enjoy the environment of the good 'ole days, and one of them is the need to build (often), tune, and repair nearly all the electronic equipment used in model aviation and model boating activities. This "Radio Controlled Model Sailboat" article from a 1948 issue of Radio News magazine is a prime example of what I mean. While knowing how to do all the work involved in the system created by these two Raytheon engineers is a great achievement, the work involved is extremely time consuming and takes away significantly from the time actually spent enjoying sailing the boat. Modern compact, powerful, reliable, relatively inexpensive, fully proportional, feature-packed radio systems are much preferred over the former. Here is a short tale of my own venture into R/C sailboating with a Thunder Tiger Victoria sloop, circa 2000...

World's Biggest Radio Telescope - SKAO

Square Kilometre Array Observatory - RF Cafe"An international team of researchers has demonstrated that the Square Kilometre Array Observatory (SKAO) is capable of detecting radio emissions from normal spiral galaxies in the early universe. The SKAO, whose construction began this year, will soon be the largest radio telescope in the world. The astronomers, who are part of the SKAO's 'Extragalactic Continuum' working group, are looking for a way to study a cosmic era in which star-forming activity suddenly decreased after an epoch known as 'Cosmic Noon.' To this end, they simulated the physical properties of the interstellar medium of galaxies similar to the Triangulum Galaxy (M 33) and the Whirlpool Galaxy (M 51) in an early age of the Universe. The results show that potential surveys should be sensitive enough to detect galaxies already in SKAO's first deployment phase..."

Television Tubes by the Thousands

Television Tubes by the Thousands, December 1947 Radio News - RF CafeIn the early days of television, what we today refer to as cathode ray tubes were called kinescopes. The kinescope on the receiving end displayed images generated by a tube called an iconoscope on the transmission end. Kinescopes had round faces onto which a rectangular picture was electronically drawn. Once manufacturing technology evolved sufficiently, it became possible to make them rectangular in order to save on material and to fit a larger picture in a smaller area. The real story as told in this 1947 Radio News magazine article from my perspective is appreciating the ingenuity of the manufacturing engineers for an ability to develop machines that handle very complex operations. They were wonders of electromechanical manipulation. There were still some operations that needed human dexterity and decision making. Oh, and I learned a new word - "lehr"...

Electronics Companies' Magazine Ads

Electronics Companies Magazine Ads (July 2022 Microwave Journal) - RF CafeIt has been my belief for a long time that the vast majority of print magazine advertisements are never seen by potential customers because very few of those potential customers ever bother to pick up a print magazine. More than a decade ago (around 2007) when I was spending my last days working in a corporate environment, I do not ever recall seeing anyone reading a trade magazine, be it Microwave Journal, Microwaves & RF, Electronic Design, EE|Times, or any of the others. In fact, most of the magazines I saw were deposited in the mail room recycle or trash bin before they ever made it to an engineer's, technician's, or manager's desk. That is not to say or imply the magazines are not excellent - they are, indeed - but even back then most people were getting their needed information online. Being able to show a print version circulation number to advertisers does not in any way correlate directly to the number of potential customers who will ever see their advertisements...

Federal Telephone and Radio Company

Federal Telephone and Radio Company Advertisement, January 1954 Radio & Television News - RF CafeCoaxial cable is the most familiar form of RF transmission line for most people these days. Up until 2009 when the U.S. switched to digital television (DTV), there were still a fairly large number of people who had the old 300 Ω twin lead cable running from roof-top antennas to TV sets. Over-the-air reception has petered off precipitously since then. Coaxial cable is undoubtedly more convenient and forgiving regarding routing since proximity to structures - particularly metallic components - is less sensitive than twin lead. Good quality 300 Ω twin lead cable (~70¢/foot today for 100') used to cost less than good quality 75 Ω RG-6 cable (~35¢/foot today for 100'), but just a couple decades ago when twin lead dominated, the opposite was true. What has not changed is the insertion loss of 300 Ω twin lead cable is typically around 2 dB at VHF TV channel frequencies (54-210 MHz), and 450 Ω ladder line (twin lead on steroids) is about 1/2 or less of that (see "Loss Figures for 300 Ohm Twin Line"). Insertion loss on RG-59 coaxial cable is around 4 dB/100' in the same band (RG-6 is ~3 dB/100', and RG-11 is ~2 dB/100')...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF 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...

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.

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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KR Electronics (RF Filters) - RF Cafe
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RF Cascade Workbook 2018 by RF Cafe

Anatech Electronics RF Microwave Filters - RF Cafe