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About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024
Webmaster:
    Kirt Blattenberger,

    BSEE - KB3UON

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.

My Hobby Website:

AirplanesAndRockets.com

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Homepage Archive - April 2021 (page 4)

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.

Homepage Archive Pages

2021:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2020:
  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2019:
  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2018:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2017:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2016:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2015:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2012:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13


See Page 1 | 2 | 3 | 4 of the April 2021 homepage archives.
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Friday the 30th

Thursday the 29th

Wednesday the 28th

Tuesday the 27th

Monday the 26th

Sunday the 25th

Friday the 23rd

Anatech Electronics April 2021 Newsletter

Anatech Electronics April 2021 Newsletter - RF Cafe"Sam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his April 2021 newsletter that features his short op−ed entitled "A Wall of Interference!" The allusion is to the "wall" of antennas that typically comprises cell tower installations. Each antenna represents a source of potential signal interference for collocated antennas' receivers whose connected front end low noise amplifiers must successfully reject out-of-band signals and/or the inbound spurious mixer products generated by out-of-band signals. Sam also presents some relevant industry news items as well..."

Electronic Speed Mail

Electronic Speed Mail, April 1961 Popular Electronics - RF CafeElectronic mail did not start out as we know it today, whereby anyone with access to an Internet-connected device can compose and send a typed message to a similarly equipped receiver. The first electronic mail message was sent (and received) on November 1, 1960, between post offices in Washington, D.C., and Chicago, Illinois. This article from Popular Electronics magazine takes you on a step-by-step tour of how the Speed Mail system worked, including its dedicated shortwave radio links between participating cities. Great care was taken in an attempt to assure message confidentiality by having the letter opened and scanned automatically inside a sealed machine on the transmit end and then printed and placed in a sealed envelope on the receive end. Knowing what we know now about government snooping...

Many Thanks to Res-Net Microwave for Continuing Support!

Res-Net Microwave Components - RF CafeRes-Net Microwave has a complete line of precision RF & microwave components including attenuators, terminations, resistors, and diode detectors for commercial, military, and space applications. Products range from the small flange type to large 2,000 watt connectorized power attenuators and/or terminations at frequencies up to 26.5 GHz. In-house photo etch and laser trim capability. The company is a leader in development and production of the films required for these type of RF/microwave components. Please check out Res-Net Microwave's website to see how they can help with your current project.

Thursday the 22nd

First Phone Broadcast

First Phone Broadcast, January 1947 Radio-Craft - RF CafeAfter having read many articles about Dr. Lee de Forest, it seems the poor guy was besieged his entire life by envious and/or belligerent electronic communications compatriots who sought to defame him and/or deny him of monetary rewards. This January 1947 issue of Radio-Craft magazine includes a dozen or so pieces written by friends and colleagues who recognized the momentous struggles and achievements of Dr. de Forest. Such burdens of fame are borne by many - if not all - persons of similar celebrity. Dogged persistence is the order of the day for experimenters and breakers-through of assumedly impenetrable walls. Guys like de Forest lived by the old adage recommending that "if at first you don't succeed, try, try again." You'll be amazed at how de Forest whipped - almost literally - that thing which was preventing his wireless telephone from working. BTW, as I've pointed out before, you will find the good doctor's last name written as "de Forest, DeForest, and De Forest." As evidenced by his signature...

Modelithics® Releases the Qorvo® GaN Library v21.4.5

Modelithics® Releases the Qorvo® GaN Library v21.4.5Modelithics is pleased to announce the release of version 21.4.5 of the Modelithics Qorvo GaN Library for use with Keysight Technologies' Advanced Design System and Cadence AWR Design Environment. Version 21.4.5 of the Modelithics Qorvo Gallium Nitride (GaN) Library includes a total of 82 models containing 59 packaged power models, 17 GaN die power transistor products and 6 small-signal models. This release offers a non-linear model for the Qorvo QPD1028L, a 750W (P3dB) discrete GaN on SiC HEMT using Qorvo's QGaN50HV process. This device comes in an NI-780 package (eared). The Angelov-based large-signal model includes an advanced model feature for enabling intrinsic I-V sensing and is valid for Class AB operations...

Programmable ICs Secured by Chaos

Programmable ICs Secured by Chaos - RF CafeAt first I thought this was a news item about Maxwell Smart's archenemy. "A complex network of randomly interconnected logic gates creates conditions that could thwart hackers. Not all chaos is bad. In the case of programmable chips, chaos can be harnessed to create a unique digital identifier. Think of it as a fingerprint—only, instead of distinctive loops and whorls on human skin, this is about the unique physical variations present in silicon chips. These minute differences, often at an atomic level, vary from chip to chip, even if they are manufactured together. The physical variations can be amplified using a technology called physically unclonable functions (PUFs) to create a signature that is unique to a specific chip..."

Hobnobbing with Harbaugh - Those Happy Happy Hams

Hobnobbing with Harbaugh, November 1963 Popular Electronics - RF CafeHere is a little electronics hobbyist humor in the form a comic series titled "Hobnobbing with Harbaugh," compliments of Popular Electronics magazine. Dave Harbaugh drew many comics for technical magazines. For the non-Ham, QSL is the Q-code for "'I confirm that I received your transmission." You don't need to be an amateur radio operator to appreciate these comic strips, though. Note that with it being 1963, the husband and wife are shown sleeping in separate beds - just like in the TV shows of the era like The Dick Van Dyke Show and I Love Lucy. BTW, the kid in the crib is spelling out -..(d) .-(a) -..(d) -..(d) -.--(y).

Many Thanks to ConductRF for Continued Support!

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

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Ziff-Davis Electronic Laboratories

Ziff-Davis Electronic Laboratories, January 1940 Radio News - RF CafeJudging by some of the letters written to magazines by their readers, obtaining parts referenced in many construction articles proved difficult or impossible to procure. Ziff-Davis, a major publisher in 1940 as well as today, ran this notice in a 1940 issue of its Radio News magazine offering advice as to how one might go about getting everything needed. Unlike nowadays where nearly every available source worldwide can be found on the World Wide Web, back then searching could be - and too often was - a long, slow process. Just finding a phone number or mailing address for a potential supplier presented a major obstacle to anyone without a collection of catalogs and magazines - or at least knowing someone who did. Imagine needing ten non-standard parts and having to write letters to manufacturers and/or distributors trying to located critical component...

Super-Thin Element Offers "Positive" Potential for Transparent Electronics

Super-Thin Element Offers "Positive" Potential for Transparent Electronics - RF Cafe"Researchers from the Royal Melbourne Institute of Technology (RMIT) have introduced an ultra-thin material for semiconductors that could lead to transparent electronics. A molten mixture of tellurium and selenium, rolled over a surface, results in the deposit of an atomically-thin sheet of beta-tellurite. As a rare "p-type" semiconductor material, the beta-tellurite transports positively charged constructs known as holes. 'This new, high-mobility p-type oxide fills a crucial gap in the materials spectrum to enable fast, transparent circuits,' said team leader Dr. Torben Daeneke. The RMIT team's new p-type semiconductor is ten to one hundred times faster than existing p-type oxide semiconductors. according to the project's team leader. 'In our advance, the missing link was finding the right, 'positive' approach'..."

4-25 new
Technology Theme Crossword Puzzle for April 25th

Technology Theme Crossword Puzzle for April 25th, 2021 - RF CafeThis Technology Theme Crossword Puzzle for April 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!

 

 

 

 

 

 

 

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 Electronics-Themed Comics June 1951 Radio-Electronics  

Engineering Job Opening

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeRF Cafe typically receives 8,000-15,000 website visits each weekday and about half that on weekends. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 13,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. 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.

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

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!

New for 2020! RF & Electronics Symbols for Visio

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

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...

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...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

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