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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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.
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Please click here to view September 2014 homepage archive page 1.
Anatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Anatech has released new designs for a 1575.4 MHz ceramic bandpass filter, 1900-2000 isolator, and a 942 MHz SAW filter. All can be ordered directly through their AMCrf web store.
Skyworks Solutions, Inc. unveils a low threshold, PIN diode limiter module that addresses the growing need for receiver low noise amplifier protection in microwave applications. The SKY16602-632LF is a fully integrated module comprised of a PIN limiter diode, a Schottky diode and two DC blocking caps designed for use as a passive receiver protector in wireless or other RF systems up to 4 GHz. It is targeted for broad market wireless systems
You have probably seen Fahnestock clips, but did you know that's what they were called? Me neither, until I first saw the name of them on a page in a MicroMark catalog a while back. When I saw this ad in Radio News, it seemed like a good opportunity pass it on. You can still buy Fahnestock clips from MicroMark. Model train enthusiasts use them for wiring their layouts since they facilitate...
You might have noticed a new layout for RF Cafe this morning when visiting. It is something I have been wanting to do for a long time, based on the information available from major search engine companies and the plethora of 'experts' regarding expectations and requirements for modern Web users. The term used for optimizing website structure and page content is 'Search Engine Optimization' (SEO). Many of the most highly recommended tactics have not been possible because of the fundamental structure of RF Cafe, which has been necessitated by commitments made to advertisers and by long-held preferences of my own. The time for major change has come, and it began a couple days ago...
SigaTek microwave specializes in high quality, high frequency microwave communication components up to 60 GHz. As a pioneer supplier of microwave RF components, the main products include directional couplers, bias tees networks, power dividers/combiners, 3 dB hybrids 90° and 180°, microwave mixers, frequency doublers, load terminations, and coaxial connectors and adapters.
MECA serves all areas of the RF/Microwave industries including world class network providers, and supporting supply chain infrastructure. We have long been the "backbone" of high performance wired and air-interfaced networks such as in-building applications, satellite communications, radar, radio communications, telemetry applications, mobile radio, aviation & air traffic communications.
"I think 'Dilbert' will remain popular as long as employees are frustrated and they fear the consequences of complaining too loudly. 'Dilbert' is the designated voice of discontent for the workplace. I never planned it that way. It just happened." - Scott Adams
Here is the latest group of vintage radio schematics and parts lists that appeared in a 1947 edition of Radio News. I know most visitors have no need for them, but posting them on the homepage helps get them into the major search engine databases. Google, for instance, scans RF Cafe every few hours, so these will be searchable by later today.
Wards Model 74BR-1055A, Farnsworth Models EK-081, EK-082, EK-083, EK-681, Philco Model 200-X Radio, Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Midget Set Radios, General Electric Model 280, Zenith Models 5R080, 5R086, Truetone Models D1747, D1748, Hoffman Model A301, Knight Model E10716 Battery Portable Radio
TradePub is a service that offers (and book excerpts), magazine subscriptions and whitepapers to qualifying engineers and technical professionals. I have downloaded many over the years and find them to usually be useful. This group happens to be related to career advancement, but the topics are widely varying. I can honestly say that I cannot ever recall being placed on any kind of annoying list as a result of signing up...
Blame my soft spot for Ford Mustangs for the reason I feel compelled to promote this installment of EDN's Sherlock Ohms, even though its subject doesn't pertain to directly to electronics. Sherlock Ohms articles all focus on troubleshooting problems whether they be mechanical, electrical, or a combination thereof. In this case, the electrical problem - a computer that erroneously caused the engine to run in a lean fuel mixture mode - was caused by a mechanical problem - a clogged PCV device. It has admittedly been many years since ...
This week's Wireless Engineering crossword puzzle's six longest words begin with the same letter. I give it a grade of 'A' for effort. As always, every word, sans none, is related to technology. Enjoy.
"The term, positive current feedback, is disturbing to some because, as is well known, positive feedback increases the distortion of an amplifier to which it is applied. This is true in this application also, but it must be noted that the net feedback applied to the amplifier is never positive but simply less negative in the region where the positive current feedback is effective." Wow, that is a lot like what politicians refer to a 'baseline budgeting.' When...
A wee bit of levity in the form of comics is good for the soul on Friday, the last day of the work week - just a few more hours to go until two days of freedom. Good humor, it is said, contains a degree of truth in it, and this group from vintage editions of Radio Craft magazine is no exception. One of the comics in particular struck a chord with me - the one with the table model radio where the serviceman is speaking on the phone with his customer. The first familiar feature is the shape...
Homodyne reception, although we don't often refer to it today using that term, involves mixing the modulated signal with a local oscillator that is tuned to the same frequency so that the demodulated signal is at baseband. In other words, the result of a homodyne nonlinear mixing process is a sum frequency of 2x the signal input and the difference frequency is DC (at the low end of the modulation). That is a simplistic explanation, and this article goes into a little more detail about methods, advantages, and disadvantages ...
This is a really nice electronic symbols chart that will come in handy for hobbyists who work with vintage electronic equipment. Not only does it have component symbols that a modern chart would not likely contain, but it has three-dimensional sketches of each device. It's too bad the chart is not in color because it would make a nice picture to frame for a decoration. If anyone with an artistic bent feels compelled to colorize it and send it to me, I'll be glad to make it available to visitors...
There is no limit to the amount of advice offered by helpful
'experts.' It's time for another round of job hunting and career advice stories. Many of these particular bits of guidance
for your life come from authors on LinkedIn, Monster, Money, etc., which typically do have good content...
• 10 Little-Known Facts About Quitting Your
Corporate Job - LinkedIn
• Fear as a Management Technique - Forbes
• 3 Ways to Wow Your Interviewer - U.S. News
& World Report
• The 3 C's of Leadership from the World's Top
Executive Coaches - American Management
I don't know Michael Dunn, but every time I see his picture on the EDN website it makes me think he's got to be a good guy to work with. After all, how many people post a picture of him/herself on a professional website with a soldering iron between his/her teeth? Where is OSHA when you need them? ;-) What got my attention this time was a picture in an article titled "Electronics of Our Youth" of a Heathkit ET-3100 Experimenter like the one I had many moons ago. The function generator in mine fried twice (replaced it once) just from being overloaded with too little external circuit impedance - poor design IMHO.
The Barkhausen-Kurz (B-K) oscillator is credited as being the first high power microwave generator that exploited the electron transit time effect. It was developed in 1920 by German physicists Heinrich Georg Barkhausen and Karl Kurz. As this article's author points out, the vacuum tube and supporting circuits were difficult to produce and were not very well understood theoretically. Shortly thereafter, the magnetron and klystron tubes came along and dominated the high power microwave generation realm. This is a good, brief explanation of...
Alliance Test is a trusted source providing sales, rentals and leasing of refurbished electronic test and measurement equipment to the R&D, manufacturing and quality assurance industries. We carry a full range of used test equipment from manufacturers such as Agilent, Ando, Anritsu, Fluke, HP, Keithley, Lecroy, Rohde & Schwarz, and Tektronix. Partnering with Alliance Test to recover 30%-40% more on your idle test equipment rather than selling to a dealer.
I have written often about the many contributions that hobbyists make to various fields of technology. Often times the efforts put out and methods used by amateurs are on par with those of professionals; the main difference between the two being that amateurs do not get paid for their work. This archived BBC video titled "Wartime Radio: The Secret Listeners," sent to me by longtime RF Cafe contributor Gary Steinhour documents how the work of two British amateur radio operators, Russell Clark and R.J.B. Hippisley, resulted in a significant strategic...
Rohde & Schwarz and Mesuro showcase their continuing collaboration on Non-Linear measurement solutions at European Microwave Week in Rome. In a joint demo at the Rohde & Schwarz booth (hall 9, booth 102), the companies present their testing solution based on the R&S ZVA vector network analyzer from Rohde & Schwarz and Mesuro's behavioral modeling formulations. The Cardiff Model Lite solution allows
X-Parameters: Characterization, Modeling, and Design of Nonlinear RF and Microwave Components, by D. Root, J. Verspecht, J. Horn, and M. Marcu. This is the definitive guide to X-parameters, written by the original inventors and developers of this powerful new paradigm for nonlinear RF and microwave components and systems. Learn how to use X-parameters to overcome intricate problems in nonlinear RF and microwave engineering. The general theory behind X-parameters is carefully and intuitively introduced, and then simplified down to specific...
World War II brought about the first wireless remotely controlled weapons. Prior to radio technology, bombs and missiles needed to either be within a distance serviceable by detonation wires, or were set off using mechanical or electrical timers. Both of those methods required the operator to gain access to the target area at a time relatively close to when the attack was to occur. Army battalions did have warheads with spooled wires attached that enabled them to control the time of detonation and even in some instances some degree of steering, but range was limited. Wireless...
Comdel designs and manufactures RF and DC power supplies and process instruments for the semiconductor, solar cell/photovoltaics, flat panel, and industrial heating industries. Comdel products are in use worldwide by the industry's major equipment and IC fab manufacturers.
RFMW, Ltd. announces design and sales support for TriQuint's TGP2615 digital phase shifter. The TGP2615 covers Ku-band radar and communications applications in the 15-19 GHz frequency range. 6-bit control with 5.625° LSB offer high resolution and 360 degree coverage. Insertion loss of the TriQuint TGP2615 is 7 dB. RMS phase error is specified at 4° while RMS amplitude error is 1 dB. The TriQuint TGP2615 is available as a
The main purpose for bothering to reprint articles like this one on analog color TV theory is to reveal the complexity and ingenuity that went into cramming a lot of information into a relatively (at the time) small bandwidth. Signals within signals and signals riding on top of and below other signals was the name of the game, and pulling it off successfully required many well-designed and well-aligned circuits. Anyone old enough to remember watching a show on analog television can appreciate the difference between a high quality...
"An expert is a person who has found out by his own painful experience all the mistakes that one can make in a very narrow field." - Niels Bohr, as quoted by Edward Teller, in Dr. Edward Teller's Magnificent Obsession, in LIFE magazine (9/6/1954, p62)
Since 1994, leading wireless electronics companies have relied on 3Gmetalworx to deliver cutting edge solutions for advanced RF/EMI PCB-level shielding requirements. From prototyping and design services to JIT manufacturing supply, our clients depend on us to provide a seamless service pathway supporting entire product lifecycle.
EDN's Kenneth Wyatt visited the ARRL headquarters building recently and posted a short story and some photos on the EDN website. The focus of the visit was ARRL's RF test lab and its RF interference expert, Michael Gruber, but there are also has some photos of archival items from days of yore.
This 60-year-old design for a coaxial line RF monitoring instrument uses components still readily available since it has no vacuum tubes and you can still buy the 1N34 germanium diodes that are used as detectors. Only 18 components (including jacks, meter, case, and switch) are used to indicate relative power, modulation percentage, and to monitor the signal modulation. Sampling is done with a high impedance tap on a through connection so that the impact on characteristic impedance on...
When civil engineers and mechanical engineers take their introductory classes in hydraulics, are the taught that the functional equivalent of water pressure in a pipe is equivalent to voltage in a battery, and that the rate of water flow is equivalent to current in a circuit, and that the diameter and surface finish of pipes are equivalent to resistance in electricity... in the same manner that electronics students are taught from the opposite point of view? The answer is 'yes,' they are. It's kind of funny how for some reason using an analogy from another familiar...
Environetix Technologies Corporation is a technology-transfer spin-off from the University of Maine Laboratory for Surface Science and Technology. A dynamic research and development organization, Environetix is making rapid and exciting progress in the field of passive, wireless sensor systems for harsh environments. We have current openings for both RF engineers and technicians who will participate in a team effort to develop and manufacture wireless microwave sensors for custom high- temperature harsh environment applications
This week's Engineering crossword puzzle includes the new name conjured up by marketing gurus for the combined company formed by RF Micro Devices (RFMD) and TriQuint. According to the press release, "conveys the combined company's ability to deliver the core technologies and innovation that will enable customers to launch their next-generation designs even faster." Let me just say the name is as intuitive to me as 'Agilent' or Keysight.'
At least for now, I am going to only scan and post Radio Service Data Sheets like these featuring the Philco Model 200-X, the Knight (Allied Radio Corp.) E10716 Battery Portable, and Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Midget Set in graphical format, rather than run OCR on them to separate the textual content. 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...
...as long as Capitalism is allowed to flourish. I know, the claim is a non sequitur, and today's Alibaba IPO is an ipso facto example. At the time of this writing, Jack Ma is worth $17.5B. Mr. Ma is a citizen of Communist China, where Chairman Mao, murderer of millions, is still idolized and his governmental tenets are still followed. Xinhua News Agency headline: "Alibaba's IPO to End US Dominance in Technology Sector." This comes as welcome news to many members of the U.S. Congress and political appointees who have publically and repeatedly cursed Capitalism...
Please welcome MSgt. (ret) Terry Butman as the newest member of the prestigious USAF Radar Technician Hall of Fame (unofficial, though, it is). Terry recently contacted me with his 20+ years of service information. Although not in a mobile communications group, Terry spent most of his career working on mobile radars like the MPN-13, MPN-14, and CPN-4. BTW, original manufacturer ITT Gilfillan's radar division now goes under the name Exelis.
Hugo Gernsback, in 1938, lampooned his contemporaries who boldly declared that by then there was nothing left to be invented regarding radio equipment for short wave communications. Wisely citing the well-known instance of a patent examiner who quit his post in 1870 because, as the man put it, all useful things had been invented and there was nothing meaningful left to patent, Mr. Gernsback challenged his readers to keep this article for 25 years and then go back and read it while being aware of all the new and wonderful short wave devices that had been invented since 1938...
Congratulations to Wouter U., of The Netherlands, for being one of two winners in the August RF Cafe book drawing. Wouter selected Understanding Quartz Crystals and Oscillators, by Ramon M. Cerda. I pay shipping so it costs the lucky winners nothing. Graciously provided by Artech House
The successful electrical engineer candidate will be responsible for the development and design of wireless control systems which will be used in Kenall lighting, emergency and signage products. The Ideal candidate will have experience using WLAN, ZigBee, Bluetooth, low-voltage control and switching circuits. Kenall products are proudly manufactured in the USA.
LadyBug Technologies manufactures the PowerSensor™ line of miniaturized USB RF & microwave power sensors. LadyBug manufactures high accuracy average, pulse, and pulse profiling sensors with GUI interfaces covering up to 26.5 GHz and 80 dB dynamic range. These sensors set a, patented industry standard, No Zero/No Cal technology. There is no need to disconnect or wait for internal zeroing and calibration.
There is a plethora of comics with just about any theme on the Internet. I could provide pages full of replications for your enjoyment, but one of the best ways to sample available comics for personal consumption and/or use in reports, presentations, etc., is to use the Search function on a website like CartoonStock. The thumbnail image above is great example where the anatomically correct mother, father, and son socket and plug family have the inscription, "Sparky! Your mother and I are shocked at your current behavior! Until you learn to conduct yourself properly, you're grounded!"
Thanks the incredible generosity of Artech House publishers, there are now many new engineering books available for selection to the monthly RF Cafe Book Drawing winners. The four shown here are among seven new titles.
Decoding the Heavens: A 2,000-Year-Old Computer - and the Century-long Search to Discover Its Secrets, by Jo Marchant. Discovered a century ago in an ancient Mediterranean shipwreck, the Antikythera mechanism instantly attracted scientific interest. It had gears, which was and remains unique among artifacts from Greco-Roman civilization. So begins Marchant's mystery about the object, a tale that ends in triumph but not before inveigling individuals who not only puzzled over the device but also became obsessively devoted to figuring it out. Tantalized by the Antikythera mechanism, scholar Derek de Solla Price felt it was the clue with which he could...
Long before their college days at Parvoo U., our two amateur electronics sleuthing buddies were on the job tracking down and trapping bad guys by using their combined knowledge of circuits and physics. In this episode, Carl and Jerry are tasked with helping a hobby store owner stop a rash of thefts that always seems to occur during a busy time right after school lets out for the day. Their first inclination was to devise a system like the big department stores were installing that used passive tags on items that would trigger an...
everything RF has updated its Cable Assembly Builder tool to help users get quotations from over 25 manufacturers at one go. Users can specify their requirement and select the manufacturers from whom they would like to get a quotation. The tool has been optimized for mobiles, tablets and desktops allowing users to access this from anywhere. Try it out.
In the 1930s, electricity and electronics were mysteries to most of the population. The concepts were relatively new and few had a firm grasp on the technology. That reality was exploited by Hugo Gernsback during the 1934 Electrical Exposition to challenge attendees to discover how the radio receiver sitting on the top of an empty, clear glass case was being powered. It was a clever ruse that reportedly stumped most people. The secret is revealed here. BTW, my guess is that an even smaller proportion of our current citizens would be able to figure it out, or for that matter
Empower RF Systems is looking for an Applications Engineer. Key responsibilities and deliverables include: Partner with sales, engineering, business development, and executive management to identify and close on power amplifier solutions for key markets and customers. Provides sales personnel with technical support for the promotion and positioning of existing and new products. Responsible for inputs to marketing plans, development of sales tools, and selected, web content preparation. Provides customer feedback to improve existing products
Anatech Electronics, a manufacturer of RF and microwave filters, has published its September 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 "Interference to Defense Systems: Tough Challenges Require Unique Solutions." There are also a couple headlines on an iPhone-based radar app, military small cell spending, and stealth wind turbines.
"By installing a booster we can increase that capability on the order of one to the fourth power." - Captain James T. Kirk, Commander of the Star Ship Enterprise. While Melanie and I were watching the Star Trek original television series episode titled "Court Martial," I picked up on a funny technical faux pas. Kirk is accused of the negligent death of a crew member with whom he has had a longtime difficult relationship. Believing that the man is faking his own death to incriminate him, Capt. Kirk has the ship's auditory sensors boosted...