Posts Tagged ‘electronics’
Resources for learning about electronics
Folks learning about electronics on their own might want to check out this great site.
You’ll find theory, practice, experiments, video’s, and a very active discussion forum
http://www.allaboutcircuits.com/
Folks interested in Radio might want to check this specific link inside the site above (Radio and Communications)
Pedagogy: Learning – and failing to learn – about Electronics
I always like this quote from major league baseball player and manager Yogi Berra –
“You can see a lot just by observing.”
Many people say the world isn’t interesting. Nothing could be further from the truth. The world is full of interesting things – if you just take the time to look.
For some, electronics is a hobby. For these folks, they are not professionals; they do not have four-year college degrees in electronics or electrical engineering. They just want to learn about electronics as a hobby. Over the years I’ve watched individuals (including myself) learn about electronics as a hobby. Generally, they try to do it on their own, outside a classroom setting – flying by the seat of their pants.
How do the variety of individual go about learning about electronics? Here is where I appeal to Yogi Berra – “You can see a lot just by observing.”
By careful unscientific and ad hoc observation, this is what I’ve observed over the years regarding people trying to learn about electronics outside a traditional classroom setting.
1. Lost-in-time Thomas Edison approach. Thomas Edison said, “Success is 10 percent inspiration and 90 percent perspiration.” For this set of individuals, learning about electronics is more about doing rather than thinking. They have the “lets see what happens” approach. They try one thing then another thing and observe the results. This is what Thomas Edison did when he was trying to find what would work as a filament in a light bulb. From Edison, “Before I got through, I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material.”
I call this approach by those trying to learn electronics as the “Lost-in-time” Thomas Edison approach because, 100+ years later, electronics is a mature disciple. At the level of pedagogy, there is no real need to “experiment” at a very basic level, For example, if you want to learn how to bias a transistor for a simple class A audio amplifier do you really want to just try combinations of resistors until it works? How many combinations will you try? “Before I got through, I tested no fewer than 6,000…”
FUNCube Dongle and the Entrepreneurial Adventure
The FUNcube Dongle is a USB-based Software Defined Radio capable of reception of 64MHz to 1.7GHz.
Far more interesting (or equally interesting) is the entrepreneurial story behind this product.
Entrepreneurs should check the archives on the blog site below going back to October 2010. Reading the history of this product gives you an insight into how products unfold from design to manufacture. There are also some great pictures of the elements that go into the manufacturing process.
Just a few sample’s
http://www.funcubedongle.com/?p=37
http://www.funcubedongle.com/?p=73
http://www.funcubedongle.com/?p=69
The main site – http://www.funcubedongle.com/
Which is a larger part of this – http://funcube.org.uk/
Dave of EEVBlog did a great video on the manufacturing of short runs of prototype products like this leading to full production runs. Very long, and detailed, but worth the watch if you are an entrepreneur manufacturing a product or if you want to see how this all works.
More Resources
Watch some videos
http://mediasite01.ceng.calpoly.edu/Mediasite/Catalog/pages/catalog.aspx?catalogId=50002546-931f-4c8c-af80-a5046f7b533c
Forum Discussions
http://cubesat.ifastnet.com/forum/index.php
Take a Video Tour of Apex Surplus Electronics
Need surplus electronics? Next time I travel to California I’m going to stop by to see this place for myself.
Definitely better than a hamfest, flea market, and better than e-bay.
Need a rocket? They have that too.
This only thing I’ve seen that comes close to Apex is this guy’s home – http://frrl.files.wordpress.com/2008/11/wa6mhz.pdf
Check out this episode of the EEVBlog (Links to this vblog and others on the right side bar — > )
Check out the web site – http://apexelectronic.com/
Check it out – Electronics Engineering Video Blog
Check out this blog – http://EEVBlog.com
David L. Jones is an electronics design engineer based in Sydney Australia.
In this blog he shares some of his 20 years experience in the electronics design industry in his unique non-scripted naturally overly enthusiastic and passionate style.
Dave started out in hobby electronics over 30 years ago and since then has worked in such diverse areas as design engineering, production engineering, test engineering, electro-mechanical engineering, that wacky ISO quality stuff, field service, concept design, underwater acoustics, ceramic sensors, military sonar systems, red tape, endless paperwork trails, environmental testing, embedded firmware and software application design, PCB design (he’s CID certified), power distribution systems, ultra low noise and low power design, high speed digital design, telemetry systems, and too much other stuff he usually doesn’t talk about.
He has been published in various magazines including: Electronic Today International, Electronics Australia, Silicon Chip, Elektor, Everyday Practical Electronics (EPE), Make, and ReNew.
Few people know Dave is also a world renowned expert and author on Internet Dating, a qualified fitness instructor, geocacher, canyoner, and environmentalist.
The secret history of Silicon Valley & the defense industry
The Secret History of Silicon Valley
This is a very long GoogleTechTalks video. But, if you are interested in “black projects” related to radio, electronics, radar, electronic counter-measures, signal intelligence, and electronic intelligence in the context of World War II, the Korean War, and the Cold War and lots of information about Stanford’s participation in classified military projects – this may be worth the watch.
If you are in to it, this is a fascinating history of military/university collaboration on black projects and the symbiotic relationship among University Engineering schools, the defense industry, and how all this gave rise to entrepreneurship in Silicon Valley and the founding of well-known companies.
Get a cup of coffee, and take a watch… (don’t foget to check out the list of references in the Resource section below)
Resources:
See below for the list sources for the above GoogleTechTalk
Read the rest of this entry »
Take a video tour of the ARRL Lab
Ever read those product reviews and tests in QST Magazine that were done in the ARRL lab? Well, here is where it happens. Take a look.
Collection of Astron Power Supply Schematics
Did you lose your ASTRON Power Supply Schematic?
Perhaps we have it in here
http://frrl.files.wordpress.com/2009/02/astron_powersupply_schematics.pdf
Electronics Projects you can build
If you like building useful electronics projects you should know about a magazine from the UK called Everyday Practical Electronics. These monthly magazines have a wealth of information along with a large number of practical projects that you can build.
The magazine is not free – it is by subscription. From time to time, EPE makes available articles on its web site.
The web site is http://epemag.com
Some archived building projects that that hams might like to build are:
Active Ferrite Loop Aerial
- http://frrl.files.wordpress.com/2009/02/0900_-_active_ferrite_loop_aerial.pdf
Microcontroller-based Morse Code decoder
- http://frrl.files.wordpress.com/2009/02/0902-_epe_morse_code_reader.pdf
A two chip radio Shortwave radio based on the MK484 chip
- http://frrl.files.wordpress.com/2009/02/0302_-_mk84_shortwave_radio.pdf
Alan did it – so can you – http://www.vk2zay.net/article/116
Have fun
Got nothing to do this weekend – why not build a laser?
Got an old DVD burner that is headed for the trash?
Wait! Use that for your weekend electronic project and build a high powered laser
http://www.youtube.com/watch?v=5erjj6aS5Ws
http://www.youtube.com/watch?v=xfj1n8vPWCE
http://www.youtube.com/watch?v=vIwaMNab5pw
As always, frrl.wordpress.com provides this for information purposes only.
As your mom & dad told you when you wanted that BB gun…
Build these projects at your own risk and with your own personal judgement
Blast from the Past – Heathkit catalogs and Learn-as-you-build Radio Education Course
Heathkit – Learn electronics as you build – Basic Radio Course (1960)
http://frrl.files.wordpress.com/2009/02/heathkit_radiobasics_ek-2a_kit.pdf
Heathkit – 1978 Catalog
http://frrl.files.wordpress.com/2009/02/heathkit-catalog_1978.pdf
Heathkit – 1951 Catalog
http://frrl.files.wordpress.com/2009/02/heathkit-catalog_1951.pdf
WiTricity – Wireless Electricity
Finally, 100 years after Tesla…
Early visions of wireless power actually were thought of by Nikola Tesla basically about 100 years ago. The thought that you wouldn’t want to transfer electric power wirelessly, no one ever thought of that. They thought, “Who would use it if you didn’t?” And so, in fact, he actually set about doing a variety of things. Built the Tesla coil. This tower was built on Long Island back at the beginning of the 1900s. And the idea was, it was supposed to be able to transfer power anywhere on earth. We’ll never know if this stuff worked. Actually I think the Federal Bureau of Investigation took it down for security purposes, sometime in the early 1900s.
What happened back a few years ago was a group of theoretical physicists at MIT actually came up with this concept of transferring power over distance…
Read about WiTricity and see it demonstrated…
http://www.ted.com/talks/eric_giler_demos_wireless_electricity.html
http://en.wikipedia.org/wiki/WiTricity
http://thefutureofthings.com/pod/250/wireless-power-demonstrated.html
The “Illustrated Man” – implantable LED Tatoos
The world is full of unprecedented opportunity. For those who think that companies can not continue to grow year after year don’t realize that human desires are infinite and unquenchable. This drives infinite product innovation.
So, what’s new at the University of Pennsylvania and Phillips?
New LED tattoos from the University of Pennsylvania could make the Illustrated Man real (minus the creepy stories, of course). Researchers there are developing silicon-and-silk implantable devices which sit under the skin like a tattoo. Already implanted into mice, these tattoos could carry LEDs, turning your skin into a screen.
The silk substrate onto which the chips are mounted eventually dissolves away inside the body, leaving just the electronics behind. The silicon chips are around the length of a small grain of rice — about 1 millimeter, and just 250 nanometers thick. The sheet of silk will keep them in place, molding to the shape of the skin when saline solution is added.
The following video may be too much for “sensitive viewers”
http://link.live.philips.com/services/player/bcpid23188062001?bctid=25240201001
We, of course, are considering the geekier side of this tech. GPS, with a map readout on the back of the wrist would certainly be useful, as would chips that cover your eyeballs and can darken down when the sun is shining too bright.
And a full-body display will eventually be used for advertising. Combine this with bioluminescent ink, for example, and you could turn yourself into a small, walking version of Times Square. At least, unlike a real tattoo, you can switch this one off.
Here is the story from Wired Magazine
In fact, if you start to imagine the possible uses, they seems almost endless. Just like the stories that play across the body of the Illustrated Man.
And for those not familiar with The Illustrated Man – http://en.wikipedia.org/wiki/The_Illustrated_Man
Related - Bio-luminescence - http://www.youtube.com/watch?v=lfQ5lHMCEDA
http://www.youtube.com/watch?v=icKB9EfURhQ
How to solder surface mount without expensive equipment
Take a Video Tour of the Ameritron Amplifier Factory
Take a Video Tour of the Ameritron Amplifier Factory
Wow. Did you ever want to see how your Ameritron Linear Amplifier was manufactured? If so, then this video is for you.
The video is quite long, and at times slow moving. But for your patience in watching this 28 minute video you will see the components and the parts that go into making the Ameritron product line plus the people that put them together. Yes Virgina, they are hand assembled by Americans.
Plus you will get to see some of the other MFJ products.
Crystal Sets to Sideband
A guide to building your own amateur radio station
by frank W. Harris K0IYE
Linear Amp Tuneup – Ameritron Al-811H Linear Amplifier
There is no stopping K1OIK Burt Fisher
Check out his video on tuning up the Ameritron AL-811H Linear Amp
If you want to see the inside of the AL-811H check out our posting below
http://frrl.wordpress.com/2008/08/03/living-life-on-hf-the-age-of-power/
The end of analog television tomorrow, June 12, 2009
Are you ready? Check out this HDTV Primer for a colletion of information
Main page – http://www.hdtvprimer.com/
Comparison of commercially available antennas – Read this first ( http://www.hdtvprimer.com/ISSUES/erecting_antenna.html ) then go here for graphical comparisons ( http://www.hdtvprimer.com/ANTENNAS/comparing.html )
Plus check out coverage maps for your area compliments of the FCC
Demo of the Flex 5000 Software Defined Radio
Can you stop Burt Fisher K1OIK? No, you can’t stop Burt Fisher talking about the Flex 5000 Software Defined Radio.
Check out Burt’s latest entry. How to use the Virtual Audio Cable on the Flex 5000 SDR for digital modes.
NYC Resistor Hacker Space
NYC Resistor Hacker Space. Take a video tour of a collaborative lab were people build funky electronics and gadgets. What is the goal? – Learn, Share, and Make things.
Maker Bot – A 3D Printing Robot. All open source. Build one for yourself from a kit. Check out a video of how it works. What’s the goal? – Make manufacturing for the masses.
Check out an article from Wired Magazine on Hacker Spaces
Get to know your Stepper Motor and the SAA1042 Stepper Motor driver chip
A while back we wrote an article on the AES IsoLoopsmall loop transmitting antenna. You might want to build your own. To make precision movements on the tuning capacitor you could use a Stepper Motor. (Limited Space Antennas – The Small Transmitting Loop Antenna: How to build your own. Or, using OPL - the AEA Isoloop
If you don’t know what a Stepper Motor is and what it can do for you, then heck, what a great time to find out.
Check out our Mashups page for background on Stepper Motors, the schematic from the AEA IsoLoop controller, datasheets for the two major IC’s, and if, you want to build one from a kit, we have the Ramsey SMD1 Stepper Motor driver kit ($35).
First, what the heck is a Stepper Motor – read about it.
Schematic from the AEA IsoLoop LC-1 Controller
This schematic has few parts and the most exotic parts are only a SA1042 stepper motor driver chip and the a 555 timer.
Datasheet for the SAA 1042 Stepper Motor Driver
Datasheet for the 555 timer
Or, Build from a kit – The Ramsey SMD1 Stepper Motor Driver Kit
PIC Programming and Electronics books on-line
“Knowledge is Power”. Check out these on-line books
Radio Receivers, from crystal set to stereoPIC microcontrollers, for beginners too
Understanding Electronics Components
PIC microcontrollers, for beginners too
PIC Microcontrollers
Architecture and Programming of 8051 Microcontrollers
Long Live The All American Five. Or, Recovering a Piece of Radio History
“Watching” the Radio
Right now, in 2009, radio and “wireless communication” is ubiquitous and part of the landscape. As such, no one really notices it. It is a taken for granted reality of everyday life.
It’s hard for modern people to put themselves in the position of people in the early 1900′s when radio was a new invention. Imagine, hearing voices and music from across the country, or across the world – without wires. Instant communications. You don’t have to wait for the newspaper to find out what was going on. Entertainment? Sure. Turn on the radio and hear Burns and Allen, Jack Benny, The Great Gildersleeve, The Inner Sanctum, Sam Spade, The Shadow, GI Journal, and hundreds more.
It’s always interesting see pictures from the 1930′s and 1940′s of a family sitting in the living room “watching” the radio. Watching the radio as if someone was talking directly to them – from hundreds or thousands of miles away. And that is exactlywhat it was – astrounding.
Recovering the Past
I can only imagine that some folks who collect old broadcast radios have some sort of appreciation for this era. When you get that radio from the 1920′s to 1940′s one can imagine how many families sat in front of that radio listing to music, news, or entertainment. Perhaps, in 2009, that family has passed away. But the radio, which you have in your hands right now, just may remember. On that radio from the 1940′s perhaps they heard the call to buy war bonds. Or, that was the radio on which they heard the start of the D-Day invasion, or the end of the war.
Hands-off Electronics: A little bit of Monica. A little bit of Erica
Read our related article: Hands-on Electronics – Signal tracing a simple transmitter
Hog Heaven at the Mailbox
The good times just keep on rolling.
Going out to the mail box I found a white envelope from CBC International. I expected more of a box – but an envelope is what I got. “You go to war with what you got.” OK, I get it.
There was my copy of The ‘Screwdrivers experts’ Guide: Do it yourself CB repair and modifications by Lou Franklin ( K6NH )
Could it get better? Yes, it was personally signed by Lou. “Best Wishes, Lou Franklin”. I am in hog heaven.
Economic Stimulus
You might think this posting is from our “We wasted our money on this so you don’t have to department. Well, yes it is. In these tough economic times you have to “spread the wealth” for the good of the country. So I made this discretionary purchase – it was my patriotic duty.
But really, I wanted to see what was in this book – I could not find it in my local public library system. This book is a companion to another book by Lou Franking “Understanding & Repairing CB Radios for the Professional Technician”
Why is there something rather than nothing?
Hands-on Electronics – Signal tracing a simple transmitter
Hands-on Electronics – Signal tracing a simple transmitter
Or, How not to be an appliance operator
Is ham radio still about electronics? If you think so, then this posting is for you.
You may want to read our nearly related article on the Heathkit radios (Collecting Heathkit Models SB-101,102 & HW 100,101 ). That posting contains a high level conceptual explanation of how the transmit section of those radios work. We think that the Heathkit folks missed an opportunity in the education market.
Heathkit had a great platform in the SB and HW series of transceivers to serve as a course in electronics – learn as you build. But that was not to be. Perhaps an objection is that there were high voltages in the Heathkits – 800 volts on the plates of the tubes. So, sticking fingers in the wrong place in a Heathkit is going to get you zapped. So maybe that would undermine ones joy of learning.
A learning strategy
Software Defined Radio – Burt Fishers (K1OIK) Review of FlexRadio 5000
Software Defined Radio:
Burt Fishers (K1OIK) Review of FlexRadio 5000
We already wrote one article about Burt Fisher K1OIK. This posting is just to draw your attention to Burts Review of a software defined radio – The FlexRadio 5000.
Folks reading reviews QST should be aware that their business model depends heavily on revenue from advertising. Theoretically, it would not be to their benefit to write less then positive reviews of products – even if it was the truth of the matter. For example, QST gets advertising dollars from FlexRadio. If QST wrote a less than favorable review of the Flex Radio products then Flex may pull advertising revenue.
This is the perennial collision of ethics and business. Consume Reports maintains objectivity of product reviews by simply making the potential conflict of and advertising dollars vs objective reviews go away by accepting no advertising. When was the last time you read in any QST review that any produt was not a wise purchase compared to other products on the market in the same category?
This is all to say, product review from real hams with no revenue at stake makes them more objective. This is not to say they do a high quality or comprehensive review – its just to say that they don’t have a devil over one shoulder wispering revenue impact when they are doing product reviews.
In any case, here is a link to burts video review of the Flex Radio 5000. This is the first in a series for the Flex Radio. We suggest you subscribe to Burts YouTube channel
Burts YouTube Channel
http://www.youtube.com/user/burt2481
Review of the Flex 5000A SDR Radio
Resources
Check out the WordPress auto generated related links about Ethics in Jouralism
Soon after that, Eidos threw a $%$#@ and withdrew their advertising from Gamespot. The rumur mill began grinding. The blogs began buzzing. Rumor has it that Gamespot lost hundred of thousands of dollars of future advertising revenue over that one bad review. Rumor has it that Jeff was sacrificed to the almighty dollar. Nobody knows how much of it is true, but the whole thing even made the front page of Slashdot. That’s about as big as a limited interest story like this gets.
Now, to be fair, nobody knows for sure that Jeff was fired for his review. I mean, it could be a coincidence that a respected, high profile, long-tenured writer was put out to pasture immediately after writing a bad review of a game that was responsible for tons of advertising revenue for his website. Maybe they were planning on firing him all along and were just victims of almost impossibly bad timing.
Jeff: Instant celebrity, official status as the “straight-shooting journalist who can’t be bought and sold.” Practically guaranteed another high-profile writing job, perhaps for an organization that understands that reviews are only as good as the perceived integrity of the reviewer.
Direct Conversion Receiver: making friends with the Signetics SA602
Direct Conversion Receiver:
making friends with the Signetics SA602 IC
Introduction
How simple can it be? If you are a minimalist and like to mess with small electronics projects then you should meet the SA602 chip. The Signetics SA602 IC is a double balanced mixer and tunable oscillator in one shot. Sounds to me like the front end of a receiver.
By adding a handful of other components to the SA602 you can build a direct conversion reciever. Direct conversion means that you process the incoming RF signal at its frequency without down converting it to an IF (Intermediate Frequency) and then processing the IF frequency.
The Ramsey HR QRP Receiver Kits
The least frustrating way to mess with the SA602 is to buy the Ramsey HR Amateur Radio Kit. This cost is about $39. These are advertised by Ramsey as QRP receivers and they are available for 20 meters, 30 meters, and 40 meters. These receivers can receive CW, SSB, and AM. The kits differ only in the external components that determine the frequency of the internal oscillator of the SA602. The oscillator in all these kits is a Colpitts varactor tuned tank circuit. The audio section is the very popular LM386 chip – the same in all the kits.
I’ve already written about the the non-linear mixing process, varactor tuning, and the LM386 audio amp IC in the article on Superheterodyne (link at the end of this posting). Read that article to get some background on receiver design that uses IF frequencies. This posting is on direct conversion and is an alternative, and historically earlier, radio receiver design.
Building the kit
It takes about 1 hr to build this kit. There is nothing complex about it. It has 84 solder points and would be appropriate for a younger person to build. Kids building this kit should have no problem – they will learn how to follow instructions, solder, identify components, and then after 1-2 hrs have something that actually does something. So if you are in to “instant gratification” then this kit may be for you (or your kid)
Power Up
Don’t expect the world from this kit. The kit is used to demonstrate the principle of direct conversion receiver design – this is a design from the 1920′s. In the history of radio, the obvious short comings of this design was overcome by Superheterodyne.
I built this kit, performed the alignment, and hooked it up to a 20 ft piece of wire. It actually does work and I heard CW, SSB, and broadcast AM on 20 meters.
I dragged out the scope to take a look at the oscillator signal. If you look at the picture to the right you will see a wire-grabber attached to the circuit board. This grabber is attached to the external components that determine the oscillator frequency of the internal SA602 oscillator. As you can see the internal oscillator in the SA602 is cranking. This is what is being mixed with the incoming RF signal. The oscillator has a tunable range of about 12MHz to 15MHz using he L2 coil (see schematic below)
If you don’t have a scope and you want to check to see if the oscillator in the SA602 is working then use a shortwave radio or ham radio. Place the SW radio or Ham radio near the Ramsey circuit board and tune around 14MHz. You should be able to hear the SA602 oscillator as a hissing or dead silence at some point 12MHz-15MHz on the SW radio or Ham Radio.
Direct Conversion – How to do it
There are 4 basic sections in the schematic
- The rough tunable input tank circuit
- The varactor tuning portion of the colpitts oscillator inside the SA602
- The SA602 double-balanced mixer – mix incoming RF with LO
- The LM386 audio amp
On the front end L1, C6, and C7 provide a rough tuned tank circuit into pins 1 and 2 of the SA602 chip. A 10K pot provides gain control by shunting some of the signal to ground.
Pins 6 and 7 of the SA602 want the tuning portion of SA602 internal local oscillator. The oscillator is a Colpitts oscillator varactor tuned by a 10K pot which reverse biases the varactor diode to tweak the capacitance which in turn affects the resonant of the tank circuit (L2 allows rough tuning). The effective capacitance and L2 control the oscillator frequency. For the 20 meter kit, the frequency is tunable around 14 MHz +- about 1 MHz.
The SA602 does all the work. It mixes the incoming signal with the local oscillator, suppresses the carrier, and produces the difference frequencies. Now here is the big deal. For some incoming RF frequency the difference of this mixing process is in the audio range. This is direct conversion. The output of the SA602 is on pin 4. Pin 4 drives the input of the audio section.
The audio section is a slam-dunk. Its a black box LM386 audio amplifier. The LM386 has enough gain to drive a small speaker.
So, that’s it. At a conceptual level, how much simpler can it be?
Conclusion
The HR20 won’t win any prizes for receivers. But, it is a simple kit that you can build in about 1 hr and demonstrate a basic principle of receiver design – Direct Conversion.
It is suitable for kids to build and “instant gratification” can be had in 1-2 hrs. Perhaps this kit can trigger the interest in a young kid who may have a yet-to-be-discovered interest in electronic or radio. Or, if you are a older ham with a lifetime of appliance operating then this kit may open the black box of a very basic reviver design that is easy to understand and actually works.
Resources
Related postings on this site -
The Age of Superheterodyne
Regenerative Receiver Design
General Electric Research in RF circa. 1934
“Remarkable short-wave apparatus, developed in the Research Laboratory of the General Electric Co., induces heating effect in the body when it is brought under the influence of 21 to 30 meter waves.
Frequency of waves used varies from 10,000,000 to 14,000,000 cycles per second. Brain action accelerated by short waves, research shows. Tomorrow, we may use short waves to keep us warm instead of a furnace.”
GE Research 1934
Innovation – RF Furnaces for individuals or entire rooms
Back in 1934 GE Research Labs found an interesting effect. If you expose a human body to RF at frequencies of 10-14 Mhz at a power level of a few Kilowatts you get a heating effect.
The idea was that this could possibly be a replacement for traditional furnaces. You would place an individual between two metal plates, turn up the juice (RF), and the person would feel warm without warming the surrounding air – as would be required by a traditional coal or wood-burning furnace.
Provided below is an illustration of how this would work for a single individual and another illustration of how this could be implemented for a small room.
It’s amazing the origin of certain ideas – plus the danger of what is unknown at the time.
Click on any image for full size in new browser window.
Click on any image for full size in new browser window.
The Wave Bubble – Protecting your personal space from RF Intrusion
The Wave Bubble
“The new device I designed, named Wave Bubble, is intended to defend the user’s personal space from unwanted wireless communication by creating a personal “cold spot” bubble where RF devices such as those mentioned do not function.”
Social Defense Mechanisms:
Tools for Reclaiming our Personal Space
Limor Fried
Meet one of the next generation of Electrical Engineers at MIT Computing Culture Group – Limor
Limor is after a Bachelor of Science in Electrical Engineering and Master of Engineering of Electrical Engineering and Computer Science at MIT.
MIT has long been known for the innovation coming from the Media Lab. So what is the relation between the MIT Media Lab and the Computing Culture Group?
The Media Lab focuses on pioneering advances in media and technology, often with the aim of improving human-machine interaction. Much of this work has been in new sensor designs, innovative interfaces, and unconventional integrations of existing technologies. While the Computing Culture group contributes to this body of work, its main focus is to investigate “how artists can refigure technology to address the full range of human experiences,” primarily from a social and cultural perspective
The Computing Culture Group at MIT…
The charter for the Computing Culture Group at MIT includes the question “What do technologists miss?” The research I have engaged takes this question and extends it to ask “What do people want technologists to develop?” Many engineers aim to design a technology (or sensor design, or interface) and then try to create an application for that technology, effectively building an answer and then inventing a need. In contrast, my research aims to identify a lived, experienced human need, and then determine how technology can address that need. Out of the “full range of human experiences,” I chose to focus on human-machine experiences and, in particular, our dislike of certain common electronic devices.
What has Limor frosted is other peoples cell phone conversations invading personal space. So what better than to select a solution for this with a thesis.
You can take a look at the attached thesis which describes the Wave Bubble. Why the Wave Bubble?
Since we cannot depend on others to respect our personal space, I have decided to instead focus on how we can defend it ourselves, using special electronic devices specifically designed to combat wireless communication technologies and televisions. Having defined the problem, I set out to design two “counter-technologies…
Attached below is a thesis submitted for partial fulfillment of a Bachelor of Science in Electrical Engineering and Master of Engineering of Electrical Engineering and Computer Science.
Take a read a decide for yourself. Do you have a right to protect your personal space from RF intrustion using the Wave Bubble?
Social Defense Mechanisms:Tools for Reclaiming our Personal Space
Beware of the Wave Bubble
These images are taken from the Thesis. Maybe a new danger at coffee shops are people wearing Wave Bubbles. Perhaps this is Linor herself demonstrating the Wave Bubble. Watch her in the fourth image in the sequence. The wearable Wave Bubble device is on her coat.
The Age of SuperHeterodyne – Building the Ramsey SR2 Kit
The Age of SuperHeterodyne
In 1918 Armstrong developed the Superhetrodyne receiver that incorporated the first local oscillator and intermediate frequency modules. The “superhet” as it is sometimes called qualifies a receiver able to function over a range or band of frequencies. The word “heterodyne” means “beating”, a technique producing a beating or heterodyne frequency by mixing two or more signals in a nonlinear device such as a vacuum tube, a transistor, or a diode mixer. The incoming frequency is converted to a fixed intermediate frequency (I.F.) where amplification and filtering are provided.
In addition, in 1922 Armstrong created the super regenerative receiver, a simplified Superheterodyne that improved the gain while simplifying the adjustment of the receiver. The “Regen” as it was called was qualified as a receiver “unsurpassed in comparable simplicity, weak signal reception, inherent noise limiting and AGC action and, freedom from overloading and spurious responses”, nothing less. The “Regen” radios took the most of very few components. However, as parts became easier to obtain, the “superhet” replaced it in all radioactivities.
Time Travelers?
Can we be time travelers? Well, yes and no. We can be kit builders and maybe later, radio experimenters and tinkerers like those Ham Radio folks of the past balancing theory and experiment to refine our knowledge. We can build kits, learn about electronics, and learn about the history of radio all at the same time. What a great deal is that! If any one of the three aspects above can hook you then the others come along for the ride – and if you are not careful, you might learn something.
Limitations of receiver design in the 1900s
So where are we in time? In the early 1900s we had the Regenerative receiver and the Tuned Radio Frequency receiver. Both of these designs had some drawbacks. The problem with the TRF design is that each stage of the radio had to be tuned to the frequency being received. So as you surfed across the band, you had to retune all the radio stages for that frequency. These radios had as many as 6 knobs to tune the stages as you skated across the band.
