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Click here to read about RF CafeView the YouTube RF Cafe Intro VideoKirt Blattenberger ... single-handedly redefining what an engineering website should be.

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"Theft from a single author is plagiarism — from three or more it is research." - Anon

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- Archives -

Man Arrested After Facebook Videos of Him Tampering with Traffic Cameras

Electronic Component Sales Are Still Sluggish

Mobile Operators Turning to Ethernet Microwave for Voice and Data Backhaul

DoD, Silicon Valley to Partner on Flexible Electronics

Creative Simulations Help Test New Weather Radar

Apple Joins Pentagon Alliance to Develop Wearable Tech

Intel Investment Spotlights Drones' Opportunity for Chipmakers

China Arrests Nearly 200 over 'Online Rumors' re Stock Market Crash and Dock Explosion

World's Thinnest Diffraction Gratings Made from Graphene

Survey Highlights Serious Cuts in Government-Funded Science R&D

Radio Revenue down $100M in 1st Half of 2015

Cellular, Wi-Fi Spar over Spectrum

Silicon Valley Wary as Pentagon Chief to Court Innovators

4G Smartphones Market Share More Than 2x, Capturing 58% in Q2 2015

Creative Simulations Help Test New Weather Radar

Van de Graaff Generator in the Tail Boom

Van de Graaff Generator in the Tail Boom - RF CafeMechanically generated electrical noise has been the bane of wireless communications since the days of Marconi. I recently posted a 1930 article from Radio-Craft titled "More About 'Man-Made' Static" that addressed the plague. Electrical noise adversely affects electronics in a manner ranging from relatively harmless but annoying interference to destructive discharging. We are very familiar with ESD and the hazard it presents to electronic devices. Triboelectric charging and a subsequent rapid discharge is the culprit. Much research has led to ingenuous mitigation and prevention techniques that have practically eliminated the problem. Still, electrical noise crops up in some of the most unexpected places and must be dealt with. An article dealing with triboelectric charging and static discharge in radio controlled (R/C) helicopters, with the resultant radio interference ...

4 More Radio Service Data Sheets
Added to the Rapidly Growing List

RCA Victor Portable Table Electrola Model R-95 Radio Service Data Sheet, July 1936 Radio-Craft - RF CafeAt least for now, I am going to only scan and post schematics & parts lists like the ones listed below, rather than use OCR (optical character recognition) software 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. I will keep a running list of all data sheets to facilitate a search.

- RCA Victor Portable Table Electrola
   Model R-95
- Atwater Kent Model 305Z 5-Tube
   32 V. D.C. Superhet
- Kadette Jewel Model 40 Chassis
   3-Tube Ultra-Midget Receivers
   Models 41, 43, 44 and 48
- General Electric Model N-60 6-Tube
   Auto Superheterodyne

Carl & Jerry: Gold Is Where You Find It

Carl and Jerry: Gold Is Where You Find It, April 1956 Popular Electronics - RF CafeYou can buy a pretty good metal detector today for a hundred dollars that will find coins buried many inches deep and larger metallic items even deeper, and you even get discriminator functions to filter out unwanted objects like tin cans. They weigh just a couple pounds and can be used with one arm. Compare that to early metal detectors that had huge induction coils on a frame so heavy that shoulder straps were needed just to lug them around. Some models came on wheels for pushing or pulling like a cart. You could plan to spend a few hundred dollars (a thousand or more in today's dollars) for one. Even then, they were not as sophisticated as the $50 models sold in Walmart now. In classic fashion, teen electronics hobbyists Carl and Jerry use their technical prowess to design and build their own metal detector and then unintentionally using it to convince ...

Bell Labs Ad: Test Tube for Sound

Test Tube for Sound Bell Labs Advertisement, December 1947 Radio News - RF CafeA lot of people like to demean engineers and scientists for their propensity to want to conduct experiments and obtain measured, empirical data rather than 'winging it' and being satisfied with 'intuitive' knowledge or the contemporarily popular term 'gut.' If mankind had not adopted scientific methods and ventured beyond the 'cradle of civilization' on the African continent, we would all still be living in grass huts, hurling rocks at prey, and foraging for berries. Quantifying and categorizing all things in nature helps inventors create new and improved implements that help make life better. Early on it was mostly individuals like Archimedes, Euler, Newton, and Edison who built the pool of knowledge that fed and evolved into corporations, governments, and universities doing the vast majority of the work. Bell Laboratories is probably one of ...

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Electronics-Themed Comics

Electronics-Themed Comics July 1948 Radio News - RF CafeHere is a batch of electronics-themed comics that appeared in the July 1948 edition of Radio News. The comic on page 122 would probably elicit cries of racism or hate speech these days, even though there is nothing racist about it. My favorite is the one that appeared on page 175. There is a growing list of other comics at the bottom of the page ...

Men Who Have Made Radio:
James Clerk Maxwell

Men Who Have Made Radio: J. C. Maxwell, May 1930 Radio-Craft - RF CafeMaxwell's inception of the theory of electromagnetic radiation is compared here to if Christopher Columbus had conceptualized the existence of America and mapped its features based solely on observations of how the known oceans and land masses interacted. I have always been amazed at the ability of people who formulate entirely new theories of science, finance, medicine, etc., and manage to detail and support their ideas with hard data and mathematics. Einstein did so with relativity, Dalton did so with atomic structure, Darwin did so with evolution, Pasteur did so with germ theory; the list is long. There are lots of geniuses out there, but a relative few change the world ...

Coilcraft Filter Designer by Nuhertz

Coilcraft Filter Designer by Nuhertz - RF CafeCoilcraft recently announced a new version of their 'Filter Designer' software, which is a customized version of the Nuhertz Technologies' 'FilterSolutions' filter synthesis and analysis program. Filter Designer will generate schematics and response curves for 3rd-, 5th-, and 7th-order lowpass Elliptic filters that incorporate Coilcraft inductors. The functionality is therefore somewhat limited and, honestly, is probably more of an advertisement for the full-blown commercial version of the software, but I did find one aspect very instructive. If you have built a filter using real-world components, then you know how sensitive inductors are to package configuration, wire winding characteristics, and placement on the circuit board. A simulation can be utterly worthless in predicting the performance of a prototype filter if the modeling is ...

Simplified Coil Calculation

Simplified Coil Calculation, May 1932 Radio-Craft - RF CafeThis might be one of the earliest printed instances of Harold A. Wheeler's simplified formulas for the three basic inductor forms. We all use them on a regular basis, but for most the origin was never known or has long since been forgotten (I fall into the latter category). I did some research on Wheeler's inductance formulas a few months ago when writing an app, so it was sort of déjà vu when this blurb appeared in a 1932 edition of Radio-Craft ...

App Note: Implementation Margin
of a Satellite Communication System

Noisecom App Note: Implementation Margin of a Satellite Communication System - RF CafeNoisecom is part of the Wireless Telecom Group. Abstract: The Implementation Margin of a Satellite Communication System is defined as the degradation of the signal after travelling through the up and downlink equipment. In order to find this, an EbNo generator such as the Noisecom CNG-EbNo Series can first be used to carry out an IF loopback test of the modem in order to find bit error rate (BER) values at different Eb/No ratios. A plot of these values can then be compared with the theoretical curve for the digital modulation scheme being used. The resultant difference is termed the implementation loss of the modem, and this value is used as a reference level for the second part of the test, in which the implementation margin of the complete up and downlink is ...

Wireless Engineering Crossword Puzzle

Wireless Engineering Crossword Puzzle for August 30, 2015 - RF CafeThis week's Wireless Engineering crossword puzzle contains the usual collection of science, math, and engineering terms, and also includes a couple topics that have been in the technical news headlines lately (clues labeled with asterisk *). Enjoy ...

RCA "Ultrafax" System 

RCA "Ultrafax" System, January 1949 Radio & Television News - RF CafeDon't let the title fool you. This 'Ultrafax' system developed by RCA in the late 1940s was essentially the first attempt at video on demand, or streaming video. Rather than piping the signal over cable or local broadcast frequency towers, a microwave link was used. While initial system equipment space and financial requirements meant only corporations, universities, and governments could procure an Ultrafax, engineers who developed the system envisioned an eventual culmination of equivalent systems in every home. Even at the end of the last century it was still not possible for program providers to personalize broadcasts to individuals. It wasn't until broadband Internet came on the scene in the 2000s that such services were possible. Now, a decade later, people watch any video they want on cellphones while riding in a car ...

Keysight Technologies Webcast: Power
Module Design for Power Electronics

Keysight Technologies Webcast Explains How to Overcome Challenges in Power Module Design for Power Electronics - RF CafePower electronics engineers designing power modules face a number of challenges; namely, size, weight, efficiency, cost, and robustness. This free, 1-hour webcast will explore these challenges and lay out a new workflow for overcoming them. Topics include modeling and characterization of components and devices, such as GaN transistors, electrothermal co-simulation, and integration of GaN into power electronic circuits. Presented by Prof. Dr.-Ing. Ingmar Kallfass, chair for Robust Power Semiconductor Systems at the University of Stuttgart, and sponsored by Keysight, the webcast ...

Linx Technologies Intros Pre-Certified,
Low Cost RF Data Modules

Linx Technologies Intros Pre-Certified, Low Cost RF Data Modules - RF CafeLinx Technologies, a Merlin, OR based developer and manufacturer of Internet of Things (IoT) Products and Solutions, is pleased to introduce its new pre-certified, low cost RF data modules. The HumPRO™ Series transceiver is built on the popular Hummingbird platform, and is a frequency hopping spread spectrum (FHSS) transceiver designed for the reliable transfer of digital data. Available today in 900 MHz, the HumPRO™ 900 MHz version outputs up to 10 dBm. This results in a line-of-sight range of up to 1600 m (1.0 mile). The HumPRO™ Series module is a completely integrated RF transceiver and processor designed to transmit digital data across a wireless link. It employs a fast-locking FHSS system for noise immunity and higher transmitter output power as allowed by government regulations ...

Fairview Portfolio with New Family
of Waveguide Directional Couplers

Fairview Microwave Expands Waveguide Portfolio with New Family of Waveguide Directional Couplers - RF CafeFairview Microwave, a supplier of on-demand microwave and RF components, introduces their new family of precision waveguide directional couplers. This release consists of 28 models covering a frequency range from 18 GHz to 110 GHz in seven popular frequency bands including K, Ka, Q, U, V, E and W bands. Fairview Microwave's waveguide couplers are available in waveguide sizes from WR-42 up to 18 GHz all the way to WR-10 up to 110 GHz. These directional couplers are offered with 10 dB or 20 dB coupling values and have high directivity of 30 dB typical with insertion loss is as low as 0.6 dB in certain models. Fairview’s new waveguide couplers are available in both standard and split block configurations and are also available in both E-Bend and H-Bend designs. They utilize a multi-hole ...

Empower RF Systems Patent Approval
"Combiner for an RF Power Amplifier"

Empower RF Systems Patent Approval "Combiner for an RF Power Amplifier" - RF CafeUnited States Patent 9,093,731 B2, recently awarded to Empower RF Systems, validates the uniqueness of the hardware architecture in use on Empower's high power, next generation amplifiers. The embodiments of this patent protection are related to the design, associated materials, and integration of the high power combiner that is integral to delivering multi-kW broadband power (CW) and narrow band pulse in an air cooled, 5U chassis (and other combinations of power and chassis sizes utilizing this architecture). "We are pleased to receive this additional recognition and patent protection for our next generation amplifiers," said Jon Jacocks, CEO. "This is a second award this year that is specific to our next ...

WiSilica Launches Smart Environment
Platform for a More Intelligent IoT

WiSilica Launches Smart Environment Platform Focused on a More Intelligent Internet of Things - RF CafeWiSilica, the smart environment enabler creating a more intelligent IoT, has launched an end-to-end solution for connecting millions of devices that can understand their environment and use predictive intelligence to improve the user experience, reduce cost and improve efficiency. Taking advantage of the existing smartphone ecosystem and WiSilica's proprietary mesh networking technology, the WiSe platform enables customers to easily configure smart homes, buildings, lighting, sensors and wearables into intelligent devices that they can manage via mobile apps and in the cloud. "WiSilica provides customers with the building blocks and framework to create complete smart IoT environments," ...

MECA Intros 6 GHz RF Attenuators

MECA Intros 6 GHz RF Attenuators - RF CafeMECA is pleased to announce the addition to our 662 series, 2 watt SMA attenuators operating now up to 6 GHz! The 662-dB-1F6 series attenuators cover all wireless applications from Hz – 6.0 GHz and available in standard values of 3, 6, 10, 20 & 30 dB. And as always made is USA carrying MECA's 36 month warranty ...