Software Defined Radio Receiver: DC to 1,700 MHz!

Modern electronics is really capable of being tiny. If you look at the projects outlined here, equipment that used to be mounted in 19"-wide metal rack panels for the military when I was in the Navy in the mid-1960s is now able to fit on a thumb-drive-sized "dongle" that plugs into your USB computer port on almost any modern computer! And the abilities of this equipment to do things the older stuff couldn't do are near boundless. When I used the specialized receivers in small communications vans or containers similar to today's shipping containers for overseas commerce, I never expected this degree of reduction in size.
Here are some links to look at this equipment, if you are interested:

A UK project for SDR:

http://www.funcubedongle.com/

About page:

http://www.funcubedongle.com/?page_id=2

And an option for HF:

http://www.ae5x.com/blog/2011/12/19/funcube-dongle-hf-converter-kit-dc-to-1-7ghz-all-mode-receiver/

It may be old news to you, but I thought I'd share this.

Ending incandescent bulb production: Are LED bulbs the answer?

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I got an email today from a non-tech friend with this link in it.
http://www.asiapacificnews.net/story/202667941#.TxO7Bn2Wej0.email

It gave me the opportunity to think about and compose an answer for that audience about my own major doubts about the state of LED bulb production as a successor for the ubiquitous incandescent illumination bulb. U.S. law caused the "phasing out" of all production of standard household incandescent bulbs beginning 1/1/2012.
http://www.usatoday.com/money/industries/manufacturing/story/2011-12-28/light-bulb-rules/52256656/1

Here is my reply to him...and to you:
Thanks for bringing that up. I first have a quote for you:

Quite a bit of the GeoBulb’s light is directional. It’s very bright directly underneath it, but if you move far off to the side, it’s not producing nearly as much incidental light as the incandescent bulb. For many situations, this isn’t a problem at all – recessed lights and lamps won’t skip a beat. However, for other uses (such as a single bulb that lights a small room), you may want to wait for next generation LEDs.

That is exactly the problem with LED bulbs. The physical function of how LEDs GENERATE light is behind the problem. Incandescent bulb filaments squirt out light as if from a point source. (Imagine a point in space that emits the same light as a 100W bulb in all THREE dimensions.) You can see the shape of the light intensity in this diagram. It is the large set of lines...just extend them all the rest of the way around the bulb.

The way an LED works is that the light is instead generated out from the SURFACE of the "semiconductor junction" that creates it. So, in the same mental state, imagine the light of a 100W bulb squirting out instead from the SURFACE of a tabletop straight up from it with some spread, but mainly only UP. Now think about how many tiny LEDs it would take to accomplish sending light in all the directions we use light from a generic home light bulb to illuminate! Being drastically efficient at squirting light out of a tiny hole (too simple, I know) is NOT the same as sending it effortlessly in all directions.

Part two of the problem is that in order to WORK, incandescent bulbs have to incandesce or get hot enough to glow white hot. So heat is part of what makes 'em work and the distribution and dissipation of that has been solved over the last 120+ years. But the heat generated by the LED function is the BANE of their existence. And dissipating it is one of the major problems standing in their way of being successful. The hotter they get, the WORSE they work. That is why the bottom part of most of the LED bulbs is a metal heat radiator. Having that metal all over the base is also one of the things that means they eat up lots of resources (metal production and crafting of the heat sink) to create. See the image below. That may be partially done away with by the top developmental quote where a company has new bulbs with liquid cooling.

In order partially overcome the part one above, the makers put many, many LEDs inside the bulb to attempt to squirt light out in several directions. But it takes a whole lot of "several" to equal "all", so they compromise by only squirting light vaguely less than that above some horizontal plane surface. That is the part of the quote about not having light off to the side of straight out the end of the bulb. This is shown by the 60º beam angle shown below where the light has already dropped off to only half what it is straight out the end of the bulb. This makes the bulbs seem more like spotlights instead of general light bulbs. If you are viewing really wide items, you might have to move the item you're viewing around to stay in the bright part of the light pattern. I do not like this.

Part three of the problem is that there are several common methods out there for powering LED's. Why all the fuss? It boils down to this:
1) LED's are very sensitive to the voltage used to power them (ie, the current changes a lot with a small change in voltage)
2) The required voltage changes a bit when the LED is put in hot or cold air, and also depending on the color of the LED, and manufacturing details.
Incandescent bulbs work over a fairly wide range, but their target brightness and effective color temperature is only achieved in a few volt range of the 120 volts we have from household power. But the above numbered statements say we can't power the LED bulb the same if it is in a 140º attic as we can when it is dangling outside in -10º blizzard. The circuits have to be very careful how they arrange this, which means NO direct application of the household power: there have to be electronic control circuits containing many components built into the base of the bulbs, thus adding complexity and room for failure of one of the tiny parts to ruin your whole $30-40 bulb, as there is no replacing parts inside the bulbs. They are manufactured so the parts are NOT replaceable by the consumer.

See how hard it is to explain the idea of what the makers of the WONDER LED BULBS gloss over in their gushing rush to get ya to buy their bulbs? These makers are trying really hard to get you to buy these darned bulbs at $30-40 a pop, but THIS EE is not havin' any o' dat. They have to get mucho better-o before I bite. And they darned well better get a heap cheaper.

Hope I didn't lose you in the discussion. I tried hard to keep it on a non-EE-level basis. But feel free to ask comment.

New use for mini-copters

This National Geographic assignment was just called to my attention. They are being used on the Serengeti to enable new views of lions and other wildlife there. There are a series of posts at the linked page that detail the photographer's assignment and the ways he has chosen to get around obstacles to achieve the best photos possible. It is worth a read.

Comments are welcomed.

New physics rider on a dark horse

There may be a new cowboy in Physics Town, riding in on a dark horse, just as the saloon is closing down for good. Check the link, pardner.

Large solar arrays come to San Antonio

There are all kinds of negative comments coming the way of renewable energy projects. We went to San Antonio this week and saw this installation. It is impressively LARGE.

"The Blue Wing solar farm near San Antonio, Texas is operational and producing 16.6 megawatts of DC power (14.4 megawatts AC). It’s the largest solar photovoltaic (PV) facility in Texas and the third largest PV farm in the U.S. The amount of generation from the facility is approximately 25,000 megawatt-hours.

"The installation includes a 500-kilowatt demonstration facility where an assortment of thin film and crystalline silicon PV modules as well as a concentrating PV unit have been installed for research and comparison purposes." Quote from Juwi Solar.

Kindle: Please not for the short of thought!

Are we ready for Kindle to be the "Short Attention Span Theater" of this portion of the 21st century? I am seriously hoping not. That's what we have quick-cut TV shows for, to mentally jerk your head (and mind) this way and that, so you can't think of something for more than a couple of seconds at a time. There are those to whom this has become more than a way of life: they seek that experience throughout life and, thus, miss out on ALL of life that takes careful thought and rumination to take in and build upon.

If you are wondering what I'm talking about, check THIS LINK out.

Comments welcomed.

Creating a file/folder text listing in Windows

Creating a file list to send others in Windows. Have you ever (like me) wanted to send someone a list of files in a folder or a list of folders on a drive? (in Windows, but you were stifled by Windows' lack of ability to perform that function?) Well, laydeez and gennulmen, SUFFER NO MORE!

I followed these SIMPLE INSTRUCTIONS and created the ability to do such in my Windows operating system in about 3 minutes, which included reading the instructions. Why the Microsoft overlords would fail to put such in the operating system is beyond me...but now it can be done.

One good thread deserves another

I recently posted this on facebook, but I realized that not all the folks who read my blog are represented there. So, enjoy the hardware view of how to get lost in the modern myriad of strange screws and screwdrivers. A partial title for it is "When a Phillips Is Not a Phillips...."

Having a ball with bearings

Having been closely involved with bearings since the 6th grade, I was nonetheless impressed with this short video telling of some of the myriad processes and machinery that make them happen in most of our devices that roll and spin and move about. Isn't technology fun?

Comments welcomed.

Boggled by farads

For technical or physics-minded folks: Recall when the news of a big capacitor was that a 0.5 to 1.0 farad capacitor would fill a good-sized barn? Well, I just heard from an old friend that there is this news that this company is now selling capacitors that are up to 5,000 farads in value!

As the friend puts it: "And I don’t mean 5000 units of a one farad capacitor… That’s 5,000,000,000 microfarads/part!"

But (and here's possibly one catch for some practical uses for these parts to replace batteries for emergency operations), the parts are rated at 2.7 volts.

Comments are welcomed.

Generation gap squeeze: Children in cyberspace

This NYTimes article about the social aspects of today's children, their interaction with electronic connections to cyberspace, the expectations they will have from those interactions, and what it will mean about the social divides between children only a few years apart in calendar age is a fascinating hypothesis and a disturbing one on the level of what it might mean in disruption to our society.

We who are older might be tempted to not think about this situation if it were not for articles like this which call it to our attention.

Comments welcomed.

50,000 hp in a used F-104 Starfighter body: Aiming for 800 mph on land!

When I used to take my mother's 1954 Plymouth out on the soon-to-open loop on the west side of San Angelo, Texas, I had nothing like this baby in mind. This fellow has lots of folks helping him get things lined up right, since there's not much margin for error at land vehicle velocity beyond the speed of sound. But the idea of cranking up 50,000 hp and lettin' 'er rip is somewhat attractive. The idea of death or months of hospital recovery if there's a mistake doesn't seem in the same breath, so to mentally speak. The subject says what happened and the plans for the future. Read the article for details.

Whoosh! Shazam!

Comments welcomed.

Old plaster walls yield no WiFi & little cell signal

Many of the places I lived in west Texas as a child had provisions for keeping chickens. I would never have thought of this problem back then. But, those places NEVER had plaster walls; they only had the wire in chicken coops.

A parallel point of view

Since we observe things with both eyes at the same time, and all light that falls on our eyes is viewed at once, we don't really think about that concept too much. This is one man's way of showing the process.

Comments welcomed.

The Cheats Who Call Us

Even if you are registered on the National Do Not Call List, companies are finding lots of ways around it. I found this on the eHow site:

Permission Tricks

1. Some scammers trick consumers into giving the scammer permission to call, despite the fact that the consumer's number is on the Do Not Call Registry. Scammers do this in a variety of ways, but one of the most common is to ask people to fill out contest entry forms at a fair, convention or other event. If you don't read the entire entry form, including the small print, you may not realize that by filling it out you have just given a company and its affiliates the right to call you. Websites often ask for your phone number and bury the fact that you've given them permission to call you in the Terms of Use or other fine print.

Comments welcomed.

"Take Back the Beep" Campaign

Frustrated by the time it takes to access your cell recorded messages left by others? Well, then, this article may allow you to vent and possibly affect how the phone carriers are doing business in that regard. The author, NYTimes writer David Pogue, tells of the obscene profits generated by all of us waiting 15 seconds or more to gain access to our messages or leave messages on another's service. Check it out!

Comments welcomed.

HAM: Spacesuit satellite answers YOUR call

Ham radio enthusiasts will go to just about any length to extend their reach into space at a little-or-no-cost boost out there. The latest thing is to have a satellite that grabs and repeats ham radio transmissions INSIDE discarded spacesuits tossed out from the International Space Station to eventually burn up in Earth's atmosphere. You can see an article on such satellites HERE. The next one is scheduled during 2010.

If you are interested in becoming a ham operator, information is available HERE. This month, I'm celebrating 49 years of being licensed in the service, so am offering a hand to YOU to join in the fun. It is a never-ending kaleidoscope of directions to go and think and do, helping others and learning new things. There are always folks to lend a hand in ham endeavors, far and near.

Comments always welcome.

ART: Typewriter ribbon tins

Another mind-boggling art form that I'd forgotten existed. I recall now seeing some of these back during my very first days of noticing things about typewriters. This series of photographs is stunning for the most part. To think of companies putting such design art effort into something as mundane as containers for single typewriter ribbons! Worth a view: here.

Comments welcome.

Electronics parts yield articulated animal robots

I ran across this post today on the MAKE: blog that discusses robot art pieces that are fashioned from large numbers of electronics and mechanical parts into the most interesting animals you can imagine. Very imaginative and inventive, to say the least!

I was following some of the links about this and I found this post of the artist's own making, that takes a few of the robot pieces even further to make extremely short videos of them going through their articulated paces! They amazed me no end!

Comments welcome.

Bach to the computer

This is the best computer visualization aid I've ever seen for music. As soon as you click to play it, immediately click on the HQ "button" and the "full screen" "button". It is quite a display. The particular piece involved in this demonstration is Bach's "Toccata and Fugue in D minor" for organ.

Comments welcome.