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What Does an Op Amp Do?

What Does an Op Amp Do?, October 1969 Popular Electronics - RF CafeHere is an 10-question quiz on the basics of operational amplifiers (aka op amps, or opamps, compliments of Mr. John Seginski, in the October 1969 issue of Popular Electronics magazine. The first commercial opamp, the μA709, was introduced by Fairchild Semiconductor in 1963. Five years later they released the μA741, which was the most famous opamp of the era; it is still widely used today. One of my electronics circuit courses in college (c1987) used the 741 as the basis for analyzing integrated circuits, and in particular, opamps. A couple companies offered vacuum tube operational amplifiers which combined two or more tubes along with some integrated leaded biasing and compensating components, and had a tube sock pinout on the bottom for plugging into a standard socket. The GAP/R K2-W, produced by George A. Philbrick Researches, is an example. It was commonly advertised in electronics magazines of the era. Today, just about everyone having any involvement knows the basic equations for calculating opamp gain for both inverting (Rfeedback/Rinput) and non-inverting (Rfeedback/Rgnd +1) configurations...

Mass Production of MXene Nanomaterial

Mass Production of MXene Nanomaterial - RF Cafe "Researchers developed an analysis model using magnetic transport characteristics of molecules attached to the surface of MXene. The establishment of a property prediction and classification system is expected to be utilized to produce uniform-quality MXene. Developed in 2011, MXene is a two-dimensional nanomaterial with alternating metal and carbon layers, which has high electrical conductivity and can be combined with various metal compounds, making it a material that can be utilized in various industries such as semiconductors, electronic devices, and sensors. To properly utilize MXene, it is important to know the type and amount of molecules covered on the surface. If the molecules covered on the surface are fluorine, the electrical conductivity decreases, and the efficiency of electromagnetic wave shielding decreases. However, since MXene is only 1 nm thick, it takes several days to analyze the molecule..."

American-Bosch 524A Radio Schematic

American-Bosch 524A Radio Schematic, June 1935 Radio-Craft - RF CafeLocating images of automobile radios from the 1930s through 1940s is a challenge. Sometimes one shows up on eBay, but those that do are usually in un-reconditioned condition, and often with missing components. Early car radios were composed of separate units holding the electronics, another for the power supply, and another for mounting in or under the dashboard. The antenna was often a rectangular loop run around the perimeter of the underside of the car or truck. This schematic for the American-Bosch 524A Automotive Radio appeared in a 1935 issue of Radio−Craft magazine. I found a very nice website - Antique Autoradio Madness - which has a large collection of schematics and photographs for automobile radio from all over the world. It does not have the exact model reported on here, but there was a lot of similarity between radios of the same vintage, so the information on this American Bosch model 624A shown in the thumbnail image to the left is probably quite like the model 524A...

TotalTemp VmSD144 N Thermal Platform Vacuum Chamber

TotalTemp Technologies VmSD144 N Thermal Platform Vacuum Chamber - RF CafeTotalTemp Technologies, a worldwide leading provider of research laboratory and production temperature chambers and thermal platform equipment, introduces their model VmSD144−N Thermal Platform Vacuum Chamber. The efficient advantages of thermal platforms are a natural for conductive heat transfer in high vacuum applications. With all the new hardware going into space, where service calls are rare, thermal vacuum testing is an important part of testing high altitude and satellite equipment. Affordable and configurable for your application. Simultaneous high vacuum and thermal testing without renting time at a test lab. Thermal platforms to fit your vacuum chamber or fully turn-key systems. Platform shown inside bell jar is 6.5” x 7.5”, other sizes and different bell jars available. Aerospace environmental testing in a thermal vacuum chamber allows for the exposing and weeding out potential problems due to extreme temperature and atmospheric pressure changes as experienced in space. With equipment destined for space, the stakes are much higher with the cost of a launch, chances of a failure could be catastrophic plus service calls in space have historically been very costly. The game of basic thermal testing in space is a little different than testing for land-based systems, mainly because the lack of heat transfer by air. The intentional and unintentional transfer of heat by convection makes a big difference from what could be common sense solution in an environment with air...

The Muzak Story

The Muzak Story, June 1955 Popular Electronics - RF CafeMost people probably associate "elevator music" with the Muzak format. It became a registered trademark in 1954, although Muzak broadcasting was around a couple decades before that. Muzak music has also played in doctors' offices, restaurants, government public service facilities, buses, retail stores, and even workplaces (to provide calm and cadence for workers). According to the Wikipedia entry, the term "Muzak " was coined by its inventor, George Owen Squier (Major General, ret.) as a play on the made-up term "Kodak;" i.e., "Muz" (music) + "ak." Over the years, a lot of scientific research went into Muzak's format including genre of music, tempo, silence ("dead") time, volume, etc. Muzak has changed hands many times, including to Westinghouse, until it finally declared bankruptcy in 2010. If you type "muzak.com" into your browser now, you get redirected to moodmedia.com. Rumors have it that rocker Ted Nugent tried to buy Muzak in 1986 just to shut it down because it represented "all that is uncool about music..."

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekdayRF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 225,000 times per year! New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be...

Thanks to Temwell for Their Support!

Temwell (filters) - RF CafeTemwell is a manufacturer of 5G wireless communications filters for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting (CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000 completed spec sheets online for all kinds of RF filters including helical, cavity, LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer, multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators, couplers, PA, LNA, and obsolete coil & inductor solutions.

Radioptics Forecast

Vintage "U.F.O." fiber optic lamp - RF CafeIn a 1963 editorial in his Radio−Electronics magazine, Hugo Gernsback dubbed electromagnetic wave frequencies above 300 GHz as "radioptics."Today, we refer to them as the sub-millimeter bands, or terahertz bands. The visual spectrum runs from around 0.63 mm (red, 630 nm, 6300 Å) to 0.36 mm (blue, 360 nm, 3600 Å). Again, Mr. Gernsback shows himself to be a prolific futurist and visionary. He was more than "all talk and no action," as he possessed many patents for his inventions and produced some build-it-yourself electronics kits. That was in addition to being a prolific writer and publisher of both fact and fiction. At the time of this article, fiber optics was a fledgling technology from a practical application standpoint. It was used in some critical communications applications due to its security advantages (difficult to tap), but in the commercial realm, those decorative multicolor fiber optic lamps were about it until laser semiconductors hit the shelf. Today, optical fiber is quickly replacing metallic conductors everywhere, most notable for Internet infrastructure...

RF Workbench™ Major Update:

RF Workbench - the world's most downloaded RF Cascade program! - RF CafeNow you can launch my classic "RF Workbench" program directly into DOSBox!!! I believe I have figured out a way to launch RF Workbench directly into a DOSBox emulator screen, without needing to first install DOSBox, mount a hard drive, and then launch the program file. Instead, simply unzip the "RFWB_DOSBox [unzip into Program Files (x86) folder].zip" file into your "Windows\Program Files (x86)" folder. Then, double-click on the "RFWB−DOSBox−Launch shortcut link" (.lnk) shown highlighted below left. Click one of the "RFWB 4.0" icons to download.

Mac's Radio Service Shop: Pride and Prejudice

Mac's Radio Service Shop: Pride and Prejudice, April 1955 Radio & Television News - RF CafeThere's not a much better way to finish up a hard week at the office than reading a new episode of John T. Frye's "Mac's Radio Service Shop." Mac McGregor and his trusty sidekick technician Barney tackle nearly every issue associated with an electronics sales and service establishment back in the heyday of radios and televisions. You might recognize the title of "Pride and Prejudice" as being borrowed from Jane Austin's classic, which, to summarize, deals with, well, pride and prejudice based on one's social status, and how it results in lost opportunities. To be honest, I have not read the book but I did see the movie version starring Keira Knightly. Anywho, you'll need to read the second half of the story to get to the actual pride and prejudice part. As for the first part, it might be difficult to imagine what all the fuss is over tape recorder usage (or non-usage as is the case here), but remember that in 1955 it meant a case with vacuum tubes and requisite heavy transformers...

Concrete + Carbon Black Supercapacitor

Concrete + Carbon Black Supercapacitor Promises Large-Scale Energy Storage - RF Cafe"MIT researchers analyzed and evaluated low-cost, easily fabricated supercapacitors that potentially offer high capacity plus structural strength. The high-density energy stage has always been a challenge, whether accomplished using electrochemistry and batteries, electric fields and supercapacitors, gravity-based systems of various types, or any of the many other options. Now, a team of researchers at MIT and the affiliated Wyss Institute for Biologically Inspired Engineering claims to have devised a technical and cost-effective solution using relatively mundane materials: concrete, carbon black, water, and potassium-chloride salts. Their approach uses a cement-based material with an extremely high internal surface area due to its dense, interconnected network of conductive material within its bulk volume. The researchers achieved this by introducing carbon black - which is highly conductive - into a concrete mixture along with cement powder and water, and letting it cure..."

Hams in Combat: A Lady of Mercy

Hams in Combat: A Lady of Mercy, July 1944 QST - RF CafeThis is another installment of the Hams in Combat series that QST magazine ran during WWII. I enjoy waxing vicariously nostalgic of a time before I was born, at time when there was still honor, courage, selflessness, and pride of country. During World War II, it was an ingrained part of most citizens, whether or not they happened to be serving in the military. Our modern day troops still have it, but sadly fewer and fewer people see their own country as any place special in the world. Sure, as General William Tecumseh Sherman famously said, "War is hell," but then again so is witnessing the tearing apart of your country from forces within - an "enemy at the gates," or a "fifth column," so to speak...

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 Werbel Microwave for Continued Support!

Werbel MicrowaveWerbel Microwave is a manufacturer of RF directional and bidirectional couplers (6 dB to 30 dB) and RF power dividers / combiners (2− to 16−way) with select models operating up to 26.5 GHz and 100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are designed and manufactured in our Whippany, NJ, location. Custom products and private label service available. Please take a couple minutes to visit their website and see how Werbel Microwave can help you today.

Electronics Theme Crossword for September 24th

Electronics Theme Crossword Puzzle for September 24, 2023 - RF CafeThis week's crossword puzzle for September 24th sports an electronics theme. This being the twenty−fourth day of the month, many of the words begin and/or end with and/or contain the letter "X." Expect a few repeats, since words with and "X" in them are harder to come by. 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, Hedy Lamarr, or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort...

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, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

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. Manufactured in the USA.

Electronic "A" Quiz

Electronic "A" Quiz, April 1968 Popular Electronics - RF CafeHere is an Electronic "A" Quiz for you to test your knowledge of terms, compliments of Popular Electronics quizmeister Robert P. Balin. The number of spaces is equal to the number of characters needed in addition to the leading "A" to spell the word. About half of them are easily identified, but the others might take some head scratching - particularly numbers one and four (hint: four has to do with vacuum tubes). Number seven's illustration could be better, so don't feel bad if you don't get it (I didn't), because it is a phenomenon only seen on cathode ray tube (CRT) displays, not on LCDs. The word "amplifier" fits for number eight, but that is not the answer sought. My score with only a couple minutes of consideration was a paltry 6:10.

Chinese Commercial Drone Threats

Chinese Commercial Drone Threats - RF CafeHigh altitude surveillance / data gathering balloons are nothing compare to the number of commercial Chinese drones occupying the skies of America. You might think the data is only going to the user. "By now, most people have heard of the People's Republic of China-based company Shenzhen DJI Sciences and Technologies. It isn't hard to walk into any electronic store across the country and find DJI drones prominently displayed. PRC drones dominate more than 90% of the United States' hobby drone market, 70% of the industrial drone market and over 80% of the first responder market. DJI rightly receives the lion's share of attention from Washington's national security watchers. In December 2020, DJI was added to the U.S. entities list over concerns about its platforms being used for foreign espionage, and Congress continues to introduce legislation targeting the company, albeit with mixed results. Now another Chinese drone manufacturer is rising in the ranks: Autel Robotics. In 2021, Autel's U.S. market share was 15%. Autel has become the drone of choice for several American law enforcement agencies. The company even sells drones to U.S. federal agencies..."

Helical Resonator Design for Filters

Helical Resonator Design for Filters Equations Formulas Charts Graphs - RF CafeThere is a frequency region between around 400 MHz and 1500 MHz where the self-resonant frequencies of discrete components make filter design very difficult, and where the physical dimensions of transmission lines and cavity filters are too large for practical implementation. One of the most prominent ISM bands (900 MHz) falls squarely in the middle of the region. Thanks to the wireless revolution, there are a plethora of SAW and dielectric filters available for the 840 – 980 MHz band, but that is about it, and they are only rated for relatively low powers (maybe +20 dBm). Helical filters fill that gap nicely, and are a combination of all three formats. Like cavity filters, the Q of the helical resonators is very high if constructed properly. That is because at the frequencies of operation, the skin thickness is getting very small and most of the current is flowing on the surfaces. Plating the cavity walls and helix with a high conductivity material increases the Q even more that bare of tinned copper...

Anatech Electronics September 2023 Newsletter

Anatech Electronics September 2023 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his September 2023 newsletter that features his short op−ed entitled "Wi-Fi: More Than High-Speed Connectivity." In it, Sam discusses the pervasive use of existing and planned WiFi networks for use in monitoring and tracking applications. The IEEE has created a new standard, IEEE 802.11bf, which "... Aims to Enable a New Application of WLAN Technology: WLAN Sensing." "This standardization project aims to enhance the reliability and efficiency of WLAN sensing and establish interoperability of wireless devices to enable a wide range of new and useful applications. Measurements obtained with WLAN sensing can be used to support new industrial and commercial applications in semiconductor manufacturing, enterprise networking, and test and measurement equipment." As the bands become more populated with users, stricter filtering will be needed, and that's where Anatech's expertise comes in...

Bell Telephone New Diode Speeds Voices

Bell Telephone New Diode Speeds Voices, August 1958 Popular Electronics - RF CafeThe first time I saw a microwave diode in this type of ceramic package was in the detector stages of the S-band airport surveillance radar (ASR) and the X-band precision approach radar (PAR) that made up the AN/MPN−14 radar system I worked on in the U.S. Air Force back in the late 1970s / early 1980s. Both radars were primarily vacuum tube systems with a few upgrades to solid state components in areas where suitable substitutes for the original tubes were available. By the time this Bell Telephone Laboratories advertisement appeared in a 1958 issue of Popular Electronics magazine, no transistors had yet been invented for operation in the microwave realm, at least not other than the "laboratory curiosity" type. It had only been a decade since Drs. Brattain, Shockley, and Bardeen announced their invention of the first transistor. As with so many leading edge technologies, this diode was developed under a Department of Defense contract. Aside from being relatively expensive to produce, early versions were available only to applications...

RF & Electronics Symbols for Visio

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

Many Thanks to 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.

Everything Happens to Me - Yogi Berra

Everything Happens to Me - Yogi Berra, April 29, 1950 The Saturday Evening Post - RF CafeWho hasn't, at one time or another, knowingly or not, quoted or paraphrased one of Yogi Berra's famous utterances? "It ain't over 'til it's over ," "Ninety percent of the game is half mental ," "When you come to a fork in the road, take it," and "It's déjà vu all over again ," are legend. They are affectionately known as "Yogi-isms." The New York Yankees catcher, manager, and coach, Lawrence Peter "Yogi" Berra, was born on May 12, 1925. Hanna−Barbera's famous pic-a-nic [sic] basket snatching Yogi Bear first appeared in 1958 (eight years after this article was written). According to legend, the ballplayer sued the bruin (not the Boston hockey team) for allegedly misappropriation of his name. The similarity of not just the name, but the Barbera part of the creator's name seemed too coincidental to be happenstance. Hanna−Barbera claimed Yogi Bear was patterned after Art Carney's character, Ed Norton, on The Honeymooners TV show. Yogi's life story is typical of a sports-loving guy of his era; would that it had been my era, too...

Anti-Collision Systems for Autos

Anti-Collision Systems for Autos, October 1972 Popular Electronics - RF CafeThis article reporting ongoing research for auto anti-collision systems and backup warning systems appeared in a 1972 issue of Popular Electronics magazine has only come to practical fruition within the last decade and a half. High-end cars were offering such equipment options in the early 2000s, but it has only been commonplace since around 2010. 1972 components were still pretty large and power hungry, and digital processing capacity and speed was significantly less advanced as well. Bendix, one of the early developers of anti-collision systems, estimated that the option on a new car might add about $200 to the price, which was a really ambitious estimate, even considering that is the equivalent of $1,4511 in 2023 money per BLS Inflation Calculator. The total add-on cost of both anti-collision and backup warning systems on today's automobiles probably doesn't even hit that figure, and the performance is orders of magnitude better. The price and sizes of transmitter signal generators and receiver sensors (antennas) are amazingly low, as are all the other system components...

Espresso Engineering Workbook™ for Excel - 9.21.2023

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has an extensive coaxial cable parameter calculator. Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience. Now that a more expandable basis has been created, I plan to add new calculators on a regular basis...

USAF's "Compass Call" Electronic Warfare Airplane

USAF's New "Compass Call" Electronic Warfare Airplane - RF Cafe"The U.S. Air Force has received its first EC-37B Compass Call electronic warfare aircraft from contractors BAE Systems and L3Harris Technolgies, industry officials announced Tuesday. BAE Systems said in a release that the Air Force will next start combined developmental and operational testing for this Compass Call, the first of 10 aircraft planned for the Air Force. The new EC-37B fleet will replace Air Combat Command's decades-old EC-130 aircraft, which the service is now retiring. BAE builds the electronic attack components of the new Compass Call in Hudson, New Hampshire, and L3Harris integrates that mission-specific hardware into a Gulfstream G550 business jet at its facility in Waco, Texas. The Compass Call will conduct a variety of electronic warfare missions to jam enemy signals, including communications, radar and navigation systems. BAE said this will include suppressing enemy air defenses by blocking their ability to transmit..."

Evolution of the Phonograph

Evolution of the Phonograph, May 1956 Radio & Television News - RF CafeWhile not a second-hand store junkie, I do like to occasionally make the rounds of the local Salvation Army, Goodwill, and other independent shops to see what kind of relics are donated. Since eBay, Etsy, and their kind have gained immensely in popularity, it is getting harder to find anything useful other than clothes and kitchen wares. A few months ago Goodwill had a 1910s vintage cabinet-style Edison disc phonograph (as opposed to wax cylinder) that was in very good condition, complete with a handful of styli and a couple old records. The original finish over smooth mahogany and burl veneers had only a few scratches and could easily be polished to look practically new. The metal hardware could have stood a fresh coat of black paint due to nearly a century of oxidation. Even the original nomenclature plate looked factory-new, and a clearly legible paper plaque of operating instructions was embedded beneath a layer of shellac. I expected an asking price of at least $500, but was shocked to see only $125 on the price tag. Surely, I thought, the employee who affixed the tag must not have realized the value of such a treasure of American history. Out of curiosity, I put a fresh steel needle in the tone arm and placed a vinyl album gotten from the music area in the store on the platter and cranked 'er up. The sound was barely discernable, so that ruled out any possibility of justifying the purchase...

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - RF CafeOne aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 220,000 per year (in six locations on each page, with >17,000 pages). That's pretty good exposure for $300 per month. Some companies have expressed an interest in being able to manage their advertising accounts themselves a la the Google AdSense program...

Many Thanks to Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF CafeAmplifier Solutions Corporation (ASC) is a manufacturer of amplifiers for commercial & military markets. 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. ASC is located in an 8,000 sq.ft. facility in the town of Telford, PA. We offer excellent customer support and take pride in the ability to quickly react to evolving system design requirements.

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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...

Copyright  1996 - 2026

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

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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