RF Cafe Software
About RF Cafe
1996 - 2016
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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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Please click here to view October 2014 homepage archive page 1.
EE Inventions Connect People & Communities
Infographics are a relatively new medium for presenting a large amount of information in a single graphic using a combination of illustrations and text with numerical data. The format is typically a high aspect vertical ratio banner, which creates a strong visual attraction that suggests a chronological progression. Ohio University’s Master of Science in Electrical Engineering program has created this infographic with the theme "Electrical Engineering Inventions Connect People and Communities." Theirs is not a time progression of inventions, but more of a snapshot of …
First Over-the-Horizon TV Bridge
In the days before satellite communications (Telstar I, c1962), long-range television broadcasts relied on an extensive (and expensive) series of line-of-sight microwave towers. Each site had land ownership and maintenance expenses, so there was an incentive to streamline operations. Development of an over-the-horizon relay system enabled a reduction in sites and streamlining of operations - at least in theory. History shows that these installations must not have provided the improvement needed to implement them on a larger scale than that reported here …
A Graphical Look at Daylight Saving Time
Daylight Saving Time (DST) ends at 2:00 am local time this coming Sunday morning in most of the U.S., whereupon we return to Standard Time (ST). The event, as with the beginning of DST in March, always elicits a lot of debate over whether DST is necessary in the 21st century. I would prefer to end the inane biannual ritual for reasons illustrated in the graph I created in Excel. Daylight Saving Time is not observed everywhere across the globe, and where it is observed there are variations in when it begins and ends. In the U.S., DST begins the second Sunday of March and ends on the first ...
New Selenium Rectifiers for Home Receivers
Selenium rectifiers were the first widely used replacements for vacuum tubes in commercial electronic equipment. Since amplification was not possible - that came in late 1948 with the invention of the transistor, compliments of Shockley, Brattain and Bardeen - diode action in AC-DC power supplies was its primary application. Typical reverse breakdown voltage is in the neighborhood of 20 volts and current handling capability depends on the interface surface area. Cost kept the selenium rectifiers from being widely adapted early in their history (1933), but by 1946 ...
Terence, This Is Stupid Stuff - A. E. Housman
Being called a pragmatist is the polite way of saying you are a skeptic, or more seriously, a misanthrope. At various times, I have been called all three (along with a few other choice terms). I prefer to think of myself as guardedly inviting of new ideas and personal acquaintances. It might come with the territory, so to speak, when possessing a stereotypically somewhat introverted 'engineer' personality. I plead guilty and throw myself on the mercy of the court. To do otherwise would be disingenuous. Why bring this up? Something I read this morning reminded ...
Schematic & Parts Lists for Vintage Radio Sets
About once a week I post these sets of schematics and parts lists for vintage vacuum tube radio sets. Most RF Cafe visitors have no use for them, but somewhere out there there is probably someone doing a restoration job on one of them and will be glad to see it. Belmont Model 5P19, Crosley Model 56FC, Garod Model 5A1, Admiral Models 7T06, 7T12, Arvin Models 555, 555A, 552N, 552AN, Emerson Models 507, 509, 518, 522, 535. Thanks for your indulgence.
Snap Circuits Electronics Learning Kit
The main selling point for this Snap Circuits kit is the ability to connect your music to it and cause many different kinds of lighting effects to respond. It is a good way to engage youngsters in electronics design because of the intense visual feedback. Create circuits with included building blocks like transistors, capacitors, LEDs, resistors, switches, motors and more - over 55 parts. There is also the Elenco 130-in-1 Electronic Playground and Learning Center with a more traditional electronics experimenter format that has many more component types. Great Christmas gifts for kids.
Orbital Sciences Antares Rocket Explodes on Launch
This really torques me off. The Antares rocket (Orbital Sciences) was originally scheduled to launch Monday evening at 6:45 pm to deliver supplies to the ISS, but was scrubbed 10 minutes before t-0 due to some dumb-a** boater running into restricted waters off the Wallops Island coastline. The explosion occurred Tuesday a few seconds after lift-off. There is a very real possibility that the explosion would not have occurred if the rocket had launched Monday since so many new variables are added after a cancellation.
Fire Danger with Lithium-Ion Batteries
Charles Murray over at Design News posted a video of a lithium-ion (Li-Ion) battery going up in flames, as a reminder of the potential (pun intended) danger posed by the chemistry used by the vast majority of our portable devices as well as the current fleet of electric cars. In it, a guy whacks an iPad battery pack with a hammer causing it to immediately burst into flames - an act that could easily go way wrong and automatically self-nominate the performer for a Darwin Award. Just as the Ford Pinto and early model Mustangs were discovered to include an unadvertised explode-on-impact feature with ...
Standards of Measurement
Buckle your mental seatbelt before reading this fast-moving rundown of the origins of many measurement standards used in the cgs (centimeter-gram-second) system. It reminds me of a video you might see of a physics dude 'wowing' an audience of science laymen as he rolls through one topic after another, among them being mass, acceleration, time, electricity, magnetism, solenoids, pendulums, inertia, and gravity. There's nothing you haven't seen and heard before in the first couple chapters of Physics 101 class in the way of equations and drawings, but ...
Engineering Career Tips for October 28, 2014
If you are soon likely to find yourself in the position of an interviewer or an interviewee, fear not. There is plenty of advice available for consideration. What you don't say can be as critical as what you do say. As someone who has been the successful interviewee at least a dozen times throughout my electronics career (only one attempt failed), my advice if you don't like rejection is as follows, in order of importance: 1) Do not apply for a position for which you are not fully qualified. 2) Optimize your resume and cover letter for the specific position. 3) Know something about the company's history and ...
OK Go - "I Won't Let You Down" Video
OK Go is perhaps best known for sophisticated videos that require extremely high levels of choreography. Their I Won't Let You Down video was posted on YouTube just yesterday and it has nearly 2.5 million views a day later. Back in 2010 I posted their Mousetrap-like This Too Shall Pass video; it now has more than 45 million views. Two major aspects of high technology are featured here: Honda's UNI-CUB β robotic unicycle and the use of a remote control octocopter drone for filming the video. Honda is not selling the UNI-CUB β yet, so the company must have been involved in the effort. The I Won't Let You Down ...
Notable Tech Quote: Physicist Richard Feynman
"It doesn't matter how beautiful your guess is or how smart you are or what your name is. If it disagrees with experiment, it's wrong. That's all there is to it." - Richard Feynman (start video @ 3:52), populist, Nobel Prize winning physicist.
Radio-Craft Incorporating Radio & Television
The announcement of the merging of Radio Craft and Radio & Television magazines into a single publication was made on the eve of America's entrance into World War II. Knowing the visionary talents of publisher Hugo Gernsback, he probably did so at least partly due to what could be predicted as a severe contraction of the domestic electronics appliance market once the war machine gears began cranking. It turns out that he was in fact prescient, because history shows that the government did direct all critical production to military equipment. Buying a new model radio ...
Anatech Electronics' October 2014 Newsletter
Anatech Electronics, a manufacturer of RF and microwave filters, has published its October 2014 newsletter. As always, it includes both company news and some tidbits about relevant industry events, regulations, and standards. This month, Sam Benzacar offers his views on the subject of "So Many Bands, Too Much Hardware." There are also a couple headlines on MRI on steroids, Biggest wireless job slashers of 2014, microwave device market poised for growth, analysts predicts 2.48% growth in EW spending, and NASA lets you
Comics with Electronics Theme
Unashamedly I offer up these vintage yet timeless electronics-themed comics for your enjoyment. I freely admit to reaching for the comics page(s) of the newspaper to read the latest antics of Beetle Bailey, Dilbert, Hagar the Horrible, Garfield, Dennis the Menace, Peanuts, Blondie, and many others. As if that was not bad enough in some people's opinion, what would really keep me from getting invited to any more high class dinner parties* if the word got out is the fact that I actually try to spot the 6 differences in Bob Weber, Jr.'s drawings. Melanie and I also like to work the ...
Civilian-Military Service Station
"Use it up, wear it out, make it do, or do without" was more than just a clever slogan during World War II. It was a way of life that extended to both civilian and military realms. While civilians were being both encouraged and compelled to make the most of what was available, military operations were scavenging, borrowing, begging, confiscating, manufacturing, and cannibalizing. France was an important center for not just resurrecting battle-damaged Handi-Talkie and other types of radios, but for taking salvageable components out of unrepairable units. The bit about grinding special crystals for the ...
Skyworks Diversity Rx Modules - LTE Smartphones
Skyworks Solutions today announced that a family of groundbreaking diversity receive modules (DRx) for LTE smartphones is currently ramping with several tier-one manufacturers. This new product category leverages Skyworks’ systems level expertise and techniques developed for cellular base stations to create a highly innovative solution integrating multiple low loss RF switches, receive SAW filters and LNAs
Engineering Magazine Editor Crossword - 10/26/2014
I have to admit to being a bit surprised when creating this crossword puzzle featuring names of editors from the RF and microwave industry's top shelf magazines. In a couple instances I discovered some people I thought were editors are not anymore, and some I did not know were editors now are. Clearly, I need to get out more. This crossword commemorates the efforts of at least eight of those editors. If I remember to do so, maybe next week's theme will be modern technical book authors.
Television in Great Britain c1945
Television development was a distant memory for most people during the dark days of World War II. Germany's forces launched its second siege of the 20th century against Europe in Fall of 1939. By January of 1945, even the Brits were beginning to feel confident that the seemingly endless days of World War II were about to come to an end. Hitler's forces had been beaten back from its massive sprawl across Europe and into northern Africa. Eisenhower's D-Day campaign six months earlier had broken ...
Radio: It's a Piece of Cake
The November 2014 edition of ARRL's QST magazine had a couple photos of some way-cool looking cakes decorated to look like Ham radios. I figured there might be a few more out there so a Google search ensued using "radio cake" as the keywords. "Few" is not the most accurate word for describing the humongous number of radio cakes that have been made. Below is a small sample of specialty cakes you can find just in the Ham and antique radio categories. In the electronics topics alone there are cakes styled after cellphones, computers, telephones, boom boxes, alarm clocks, microwave ovens, ...
PhotoMath OCR-Based Algebra Solver App
Algebra class just got easier for high school math students with smartphones (ok, that last part is redundant). PhotoMath is an app that uses OCR technology to decipher a polynomial algebraic equation and perform operations on it - like solving for unknowns. microblink's "Vision" app provides the OCR (blinkOCR) part of the functionality since it already knows how to take a picture of text and convert it to ASCII type characters based on its 'text recognition, barcode, and ID scanning' algorithms. PhotoMath then takes the process a step farther by figuring out what needs to be ...
** Censored ** 1945 Fusite Advertisement
I'm guessing once word got out about the Fusite advertisement in the 1945 edition of Radio News, there was a sudden surge of interest in buying electronics magazines by young boys. Even by today's rather loose decency standards this mermaid depiction would undoubtedly cause an outcry. Imagine my shock in turning to page 90 and seeing this illustration! Why, I had to stare at it for many minutes to believe what was before my tender eyes ;-) Of course since RF Cafe is a family friendly website I did the responsible thing and blurred the offending anatomical portion of Cincinnati Electric Products ...
Telemakus App Note on Phase Shifter Fundamentals
RFMW announces an application note detailing the fundamentals of phase shifters including theory of operation, critical parameters, and applications for test and measurement. Telemakus offers USB controlled phase shifters covering 1-8 GHz with 12-bit DAC resolution and greater than 400° of phase control. Models extending the frequency coverage to 18 GHz are discussed. The application note outlines key phase shifter parameters and how the Telemakus phase
Free Engineering White Papers - October 2014
"We do less with less," is what a senior engineer at a major defense electronics contractor once remarked to me as he grew more and more infuriated with a malfunctioning antiquated component specification database microfiche machine the company insisted on keeping in spite of a modern computer-based alternative. Remember those frustrating contraptions? That instance came to mind when I saw this white paper titled, "The Engineering Workforce Problem: Doing More with No More." Since my last excursion to the TradePub website they have added a lot of white papers with topics on PCB design that might be interesting ...
Coil Coupling Problems
When you look at the circuit board and/or chassis of a radio set - new or old - you see a lot of components including resistors, semiconductors (and/or vacuum tubes), inductors, capacitors, transformers, switches , potentiometers, shielded cables, shielded compartments, displays, indicator lights, connectors, etc. With the possible exception of some semiconductors, the function of just about every component can be discerned by most people who are at all familiar with radio electronics by ...
Satellite Comms Ground and Earth Station Handbook
The Satellite Communication Ground Segment and Earth Station Handbook, by Bruce Elbert, explores the delivery end of the satellite link and its relationship to delivery of services. From international telephone network gateways to direct broadcast home receivers, today's broad range of ground systems and devices require satellite communication engineers and business managers to have a broad and sound understanding of the design and operating principles of earth stations and ground control facilities ...
Sherlock Ohms: The Singing Telephone Switch
This adventure of Sherlock Ohms is useful to read because it demonstrates the importance of finding the root cause of and truly correcting a problem rather than stopping when a lesser solution that is merely a 'band aid' type cure would be easier. The less desirable action would have been to de-rate the number of circuits that could be serviced by each system since it was initially discovered that the problem only occurred when the board count went above ...
Needed: Electronic Inventions
I and others joke frequently about the promise of flying cars, automated homes, and miracle pills to cure any ill that were predicted to be commonly available by the end of the 20th century. Magazines like Popular Science, Mechanix Illustrated, Science and Mechanics, et al, regularly printed stories about these and a host of other inventions that were just around the corner. Most have never been realized, but we're appreciative of the dreamers and those people who dedicated their lives - often to the point of financial and/or physical ruin - while trying to succeed. Taking a different approach, ...
ATEC Needs a Calibration Technician
Advanced Test Equipment Corp is a nationwide company that focuses on the rental of a wide variety of equipment working in a fast paced environment. We are looking for and experienced Calibration Technician to calibrate, troubleshoot, and repair a wide variety of equipment, including but not limited to: analyzers, GPTE, fiber optic, scopes, meters, power supplies, and more.
Carl & Jerry: Two Detectors
Just in time for Halloween, John T. Frye's teenage sleuths Carl & Jerry unexpectedly recorded a late-night conversation between two men where they plot how to dispose of the 'body' when death occurred as a result of prolonged choking. Employing their trademark technical prowess and scheming ability, the pair sets a trap for the perpetrators and dutifully summon the authorities as they complete their nefarious act of the night before. Halloween comes into play because the recordings were made for ...
Construct a 56 Megacycle Magnetron Transmitter
Magnetrons are fairly ubiquitous in society these days for use in heating, radar, and even lighting. They were probably the first useful means of producing high power microwave signals. The concept was first brought to fruition in the early 1920s as a laboratory curiosity and rapidly developed into a practical type of device with many applications and spin-off products like the klystron, the traveling wave tube, and the cross-field amplifier. This ...
Notable Tech Quote for October 21, 2014
"For disappearing acts, it's hard to beat what happens to the 8 hours supposedly left after 8 of sleep and 8 of work." - Doug Larson, columnist. This appears in the 2015 edition of The Old Farmer's Almanac. The article in which it appeared, "Where Does the Time Go?," has a lot of anecdotal information about how long people live, average sleep time, TV viewing time, work commuting time, pace of life, etc.
TriQuint 5 W SPDT Switch Covers 13 to 19 GHz
RFMW announces design and sales support for a Ku-band SPDT switch capable of handling 5 W of RF power. The TriQuint TGS4310 is a SPDT reflective switch fabricated on TriQuint's 0.15 um GaAs production process. Operating from 13 to 19 GHz, the part handles +37 dBm input power with <0.1 dB compression and less than 1.7 dB insertion loss. The TGS4310 is available in a small 1.00 x 2.14 mm die size and requires very little control current allowing for
Tech Comics from Keysight (cum Agilent cum HP)
While researching lab wall charts last week, I happened upon a large collection of electronics-related comics on the Keysight website. They are clever puns on familiar engineering themes, professionally drawn by artist Rand Kruback, and very colorful. Permission for usage, presumably with proper attribution to the source, is granted "For your lectures or in your labs." Screen savers are somewhat passé these days, but if you are one who still sports such things, you can download ...
Scanning Electron Microscope for Radio Engineers
Television and radio facsimile machine electronics technology was credited for aiding in the development of a new type of scanning electron microscope (SEM) that could image the surface of opaque object to a resolution of 100 Å. The television contribution part of the technology was precisely controlling a raster path for the electron beam. The facsimile part is the knowledge of how to assemble a printed image from streaming data. It is interesting to note that in order for an object to be imaged via SEM, its surface must be electrically conductive. Accordingly, non-metallic ...
Vintage Radio Schematics & Parts Lists
Here are another half dozen sets of schematics and parts lists for vintage radio sets. These are being posted for the sake of the relatively few hobbyists who still take on the challenge of restoring these old relics of yesteryear. I've finally resumed work on my Crosley 03CB console cabinet radio. My nostrils are filled with 70+ year old walnut wood dust from doing the final sanding in preparation for staining and polyurethaning.
Test Equipment Crossword Puzzle
This week's engineering crossword puzzle has a theme of test equipment. The four longest words are types of test equipment, and a few of the other are as well (or related to test equipment). All the other words are from my hand-selected library of a couple thousand terms related to engineering, science, mathematics, etc. Enjoy!
I Have a Few Questions About Ebola
I listen to a fair amount of radio and read news headlines throughout the day, so I have heard and read a lot about the lurking Ebola epidemic. Like most RF Cafe visitors, I am at least as informed on topics like viruses as the average citizen of the world. We know that there is no 'cure' for a virus per se, just a possibility that it can be subdued by disrupting its ability to replicate. Unlike bacteria which are cellular and have their own support system, viruses require the metabolic mechanisms of a host in order to ...
Foreign Broadcast Intelligence Service
You will not find the name Central Intelligence Agency (CIA) mentioned anywhere in this WWII era story reporting on the activities of the Foreign Broadcast Intelligence Service, but it was then and is now a branch of the CIA. Per the CIA website "For nearly 70 years, the Foreign Broadcast Information Service (FBIS) monitored the world's airwaves and other news outlets, transcribing and translating selected contents into English and in the process creating a multi-million page historical archive of the global news media." Equally surprising is that the BBC ...
American Amphenol Tube Socket Wall Chart
Earlier this week I posted a page pointing to the many laboratory wall charts offered by Keysight Technologies. I mentioned how unlike modern charts that are full of color, the old ones were usually a single color or black & white. Here is an example from American Amphenol in the mid 1940s. Something like this would make a really cool decoration for today. I just looked on eBay and didn't see an Amphenol Tube Socket Wall Chart for sale, but that would probably be the bet place to latch on to one eventually.
Hewlett Packard Archive Website
Website contributor Joe Cahak reminded me of the Hewlett Packard Archive website that is absolutely the go-to source for vintage HP documents. According to the site's owner, Glenn Robb, there are more than 35,000 pages of Hewlett Packard catalogs, Bench Briefs, product manuals, service notes, Watt's Current, price lists, periodicals (Measure and Insight magazines), journals, presentations, HP Test and Measurement News, seminars, application notes, and much more ...
Inventor Testimony in Patent Litigation
Attorney Joshua Fruchter, Esq., has posted an article that made me think about how to a large extent the practice of law is a lot like writing HTML code for a web page. Think of a lawyer as a programmer who writes his HTML code to produce a specific output for a specific input. Codified law is analogous to the HTML specification as published by the W3C. The judge and/or jury is equivalent to the browser creator. As we all are painfully aware, even relatively simple web page code can end up displaying vastly differently on not just browsers from various manufacturers (Chrome, IE, Firefox, Safari, ...
New RF & Microwave Magazine Articles
It's time for another round of RF & microwave articles from our industry's top tier magazines. Happy reading.
• Slot Antenna
Tames 3 Wireless Bands
W. Maowen, C. Jianzhong, P. Wenjuan
• Cut the Defense
Budget? Sure, No Worries,
Ten Years of Transistors
Did I ever tell the story about a manager I had at a major defense electronics firm who thought he could make an NPN transistor by wiring two diodes in series with the anodes tied together? He reasoned that since a bipolar junction transistor consisted of three alternating layers of n-type and p-type silicon, the device could be affected per his scheme. That was in the mid 1980s when I was still a technician (working diligently on my BSEE degree at night). Needless to say the engineers who worked under him were not too impressed with ...