EVCalc2: A Calculator for Electric Vehicles

Who has time to read? You can just download the calculator here.

If you want to know how it came about, the story goes like this: About four years into my engineering career at NASA's Jet Propulsion Laboratory, I got the chance to attend a series of lectures put on by Aerovironment at Caltech. Aerovironment was an early green company, maybe the first with a lineup of such heavy hitters. The lectures were entitled the "Sunraycer Lectures". They detailed how Aerovironment had won the Australian Solar Race in a car called "Sunraycer". Official sources say GM put almost two million dollars into the Sunraycer. The figure I heard was higher than that. The Sunraycer was a forerunner of the Impact. The ill-titled Impact was later renamed EV-1 and featured prominently in a movie called, "Who Killed The Electric Car". A system-by-system account of the Sunraycer was given by each of the principals: Peter Lissaman's shape, Al Cocconi's on drive train, Ray Morgan's body layout, Bart Hibbs material choices, etc. Several figures of note gave presentations on their subsystems. There was a systems engineer and a structures guy who did the "landing gear".

For a final, attendees got to do a design, I did a solar-to-steam car design intended to work around the low efficiency of solar cells and built a scale-model, but I'm getting ahead of myself.

Peter, as in Dr. Lissaman - had a famous gliding airfoil named after him. He opened with a lecture about GMR method, which stood for Goal-Method-Result. I never met Sir Edmund Hillary, the first conquerer of Everest, but Peter looked and sounded like Sir Edmund to my imagination with his bold declarations and British accent. Lissaman had decided to fair the flow at the rear of the Sunraycer with "chines", discrete panels that would allow the solar cells to be attached without bending them excessively. Later designs would smooth the tail completely, but the shape was interesting and met the fabrication needs of the time. It also made for a car with an extremely low drag coefficient, 0.125, the lowest ever achieved at that time.
Al Cocconi was an electronic genius, cut from the cloth of Apple's Steve Wozniack, but by rumor, a bit more temperamental. He had figured out that high voltage AC made for a more efficient use of a battery's limited energy compared to the low voltage DC that characterized golf-cart techology of the time. He used power MOSFET's, control circuitry and a host of cool tricks to produce a drive train that was extremely energy efficient. He later invented the first hybrid, part of which was in a trailer towed behind his car, and worked on aircraft that can stay aloft for days, but those are tales for another day.
Ray Morgan was a down-to-earth engineer who talked about how Kevlar was better than Boron composites if you're in the ER after an experimental aircraft crash, because they "don't have to pick the boron splinters out of you one at a time". Ray could build stuff, in that enigmatic Mythbuster's sort of way. He talked about "Hot Shot" glue, a methacrylate glue that allowed you to put things together fast in a prototype and how you could pound the ends of fine tubing with a hammer so you could drill and fasten them together with a bolt. He is shown here shaking hands with Burt Rutan. Morgan is on the right.
Bart Hibbs, son of Al Hibbs (the voice of the Voyager spacecraft), talked about Spectra vs. Kevlar. Spectra is stronger and lighter but had the disadvantage of "creep". This meant that a Spectra panel or component placed under sustained load would actually change shape over time and usually in a way you wouldn't want. The load dynamics of Spectra, from the slow responding viscoelastic ones, to the high speed stiff response encountered in parachute openings made it a questionable material in some sense. A generation of skydivers would discover this the hard way. Bart was smart like his dad and didn't miss details.

Paul had a habit of only hiring CalTech Ph.D's for quality-control reasons, just as Honda liked Art Center College of Design people. Great if you went there, sad if you didn't. During the lectures Paul MacReady himself would chime in with the wonderful observations and questions. He reminded me of Richard Feynmann, and had most certainly attended lectures by Feynmann during his time at CalTech where he received a Ph.D. in aerospace engineering, or somethign akin to that. Paul had already distinguished himself on numerous occasions, the most notable of which was his winning the Kremer prize for the FIRST human-powered flight. Paul had worked on the wing of the DC-9 and asked himself, "What happens if you cover it with clear plastic sheeting instead of aluminum?" Paul had a knack with doing calculations that simplified things and figured out that a person on a bicycle produced sufficient power to keep such a wing aloft. The early prototype was secreted in a hanger with a landing gear of toy firetruck wheels. The final version hung in the Smithsonian.


One thing I remember was Paul, or by title, Dr. MacReady was defining specific energy in an easy-to-apprehend way. A battery had enough energy to lift itself so many feet. Different battery types could then be ranked by how far they could lift themselves and indeed any energy storage or conversion scheme. The Sunraycer used batteries you could make in your kitchen with silver foil and potassium hydroxide. A similar battery was used on the moon vehicles. Light and powerful, the name of the game in electric cars.

Now all this took place in the context of yours truly bicycling back and forth to work, and I got really tired of breathing LA exhaust fumes, which drifted north to Pasadena and clung in an opaque and stupefying fog that hid the mountains that would light on fire from time to time.

After finishing the course, it all seemed kind of straightforward, except for the two-million dollar part. It came about that a certain fellow and I cooked up a scheme by which we might retrofit existing cars by removing their internal combusion engines and replacing them with a drop-in "electric-car conversion." We picked the Geo Storm as a starting point because it was trendy and quasi-aerodynamic. The sales guy was more than happy to hear this.
I immediately began mechanical design of the "module" and collecting the components for a prototype, sinking about $30,000 into credit card debt in the process. The fellow that I had originated the concept with parted ways with me, and I was left holding the bag and running out of funds, never finished the prototype. Coincidentally, there was almost no demand for electric cars. Later simulations would show that our "modular motors" concept was somewhat ill-fated from the start. If I had done these simulations at the beginning of the project, this would have been understood with considerably less pain. The mantra that emerged from the simulations was, "Electric? Half the Car at Twice the Price", due primarily to the range limitations of the lead-acid and nickel-cadmium battery technologies of the time.

So I decided to take the basic parameters of an electric electric car, including hybrid APU's and solar panels if desired and codify them as a set of calculations. The sophistication comes from the number of related issues, "pushing on this pulls on that".Those calculations can save you a great deal of pain, dollars on the cutting-room floor, and get you closer to realizing the ideal of a practical electric or hybrid electric car. I ask a few dollars for the software, but according to my experience, its a pittance compared to $30,000...

Van / wdv.com

Filamentary Rotations

I don't know where to begin, so let me just get a few ideas on the table, to see if a whole will emerge.

A degree of freedom is something like movement in the x-direction. Move over, move back. This degree of freedom is big, because we can see the movement if it is large enough.

So we might call this idea of a freedom of movement in the x-direction a dimension.

A line of this movement, or a filamentary curve is something we can slide a bead along. We assume that we can label subsequent positions of the bead as we move over and move back, and if these labels are consecutive numbers, we can use them to say where we were, where we are, and where we will be.

This filament of possible movement is so large we will call it a large dimension - a large degree of freedom.

But now take the bead and twirl it. The bead can also have another degree of freedom, a rotation.

But assume for a moment that we allow the bead to shrink, ever smaller and smaller, till it is just the size of the filamentary curve itself. We can talk about the rotational station of this bead, but the degree of freedom itself is curled up, too small to see, so we might call this a small dimension - a small degree of freedom.

We can also think about labeling how curled up the bead is by naming the turns or parts of a turn the bead has made. If these names are consecutive numbers we can use them to say where we were, where we are, and where we will be.

Now we are ready to talk about the first idea.

If we have something that is moving in a large dimension along a curve or line, we can resolve this movement as movements along a set of complementary axes. Then we can say that movement along our arbitrary filamentary curve has this much movement in the x-direction, this much movement in the y-direction, and we can use these pairs of labels as perfectly adequate alternative names for the position of the bead along the arbitrary filament.

If you have ever spun a bicycle wheel and held onto the axle in each hand, you will know that the wheel doesn't like to be tilted. It resists this tilting with an inertial force called the gyroscopic force. The gyroscopic force wants to keep the wheel spinning in its original direction and complains by resisting if the wheel is tilted to spin in some other plane of rotation.

All the points on the wheel except the very center, can be represented as translations through space, they aren't rotating at all! But the very center of the wheel (we pretend the axle is rotating too) has an axle, an axis of rotation, and there is an infinitesimally-wide dimension where the movement is pure rotation with no translation. This is a small dimension, because it can never be seen. A more apt name for it might be an invisible dimension.

If the bicycle wheel became like the bead, and became infinitely small, it would have no gyroscopic force. So it could be spinning in one direction, and then that whole assembly could be spun in a second direction and we could resolve spins in one direction into components of spins in multiple other directions as we did with translation above.

Now for the second idea.

If we count up the directions that we live in there are three, and for each of these directions there are three rotational degrees of freedom. Then there is the passage of time. So we really live in a six dimensional sort of space, if we count the invisible dimensions of filamentary rotation, seven if we consider time to be a dimension, but it doesn't have the same freedom as the others. We are stuck in it.

The third idea.

I should stop here, but I am afraid I might lose an important idea, so I will just add something that I find interesting. We rarely talk about the position of a photon. We can talk about where it originated, or where it might be after a time, but the native state of a photon is not really its position, but rather its velocity, which in a vacuum is just c - the speed of light.

But this is a translational velocity and I want to know if there is also some kind of native rotational velocity of a particle, say a photon, or even some other kind of a fundamental building block, perhaps an electron. The spin of an electron is one of its four pieces of state information. My question is, how fast is it spinning?

So putting the last two ideas together we see that it isn't just where something is that is its native state, but rather how fast it is going that characterizes something important about it. How fast something goes is a degree of freedom - a dimension also.

If we add up where things are, and how fast they are going in translation and rotation we come up with 12 degrees of freedom, or 12 dimensions. That plus time makes 13, which just happens to be my lucky number...

An Excerpt from Ham Radio Field Day 2009

Because of an exhausting 50 mile bike ride in the hot sun, I couldn't make it to Field Day on Saturday. I woke up late on Sunday, hoping to make some kind of belated appearance.

Just for fun, I started my HamTrack system at 9:47 am - a mashup of Google Earth, CW Skimmer, and C++ programs, glued together with some Unix tools, sed, grep, awk, along with the usual database fiddling and geolocating.

It is an end-to-end automated signal tracking system that translates RF morse code into pins on a map. So I left it running and headed over to the real Field Day, where, after catching up with my buds, I managed an impressive 2 contacts 15 minutes before the end of the event at 1 PM.

When I got home I discovered that 308 stations made 917 calls while I was gone, illustrated as pins in a map below. As in the 24 hour case, (previous blog), pins are colored by frequency, red for 6.9 MHz, blue for 7.1 MHz and spectral coloring in-between. My pin AE5CC is arbitrarily assigned red so I can find it in the sea of pins.

You will need the Google Earth browser plug-in to view the interactive map, and it takes a few seconds to load the data - about the time it takes to read this. If you don't use Google Earth, you're missing the best thing since sliced bread. - AE5CC

An Extreme Soft Radio Adventure - 24 Hrs @ 7 Mhz

After some antenna simulations using 4Nec2 (by Arie Voors) I wrapped a wire around my townhouse to create a loop HF antenna. I was curious if it was working and how the actual propagation pattern compared to my predictions. So I left my software defined radio, a Softrock 6.2 (by Tony Parks and Bill Tracey), running for 24 hours. It turned out to be quite an adventure!
Results: 1138 stations made 4907 calls, illustrated as pins in a map below. The pins are colored by frequency, red for 6.9 MHz, blue for 7.1 MHz and spectral coloring in-between.

Mouse over the map to see calls from the Island of Midway to Puerto Rico in longitude, from Alaska to Florida in latitude.

You will need the Google Earth browser plug-in to view the map, and it takes a few seconds to load the data - about the time it takes to read this. If you don't use Google Earth, there is an image at the bottom of the page. - AE5CC

Printing Circuits

While talking about building circuits, my very talented friend said to me:

“For me, soldering is a way to turn money into smoke.”

If you think about it, soldering is a very primitive activity. It is a cauldron of molten metal from the Middle Ages whose sole alchemy is making a single connection. A connection known for toxicity and burns. Toxicity, because until recently solder was full of toxic lead, and some are talking about returning to lead because of the whiskers that form with lead-free solder (ROHS compliance). Burns? Burns on both hands from soldering accidents over the years. None of which confer the ability to keep from getting burned again. Solder for regular people melts at 360 degrees F. The iron is over 500 degrees F. A soldering iron left unattended can burn down the house.

Most metals conduct with low resistance. You can, if you try hard enough, get other things to conduct, like certain plastics, but they are never as good.

We are children of the integrated circuit, invented by Jack Kilby at Texas Instruments in 1958. From then on printed circuits took off. Now you can get almost any circuit you can think of for FREE in something called a sample program. You ask the vendor and they send sample chips for free. Then you make something, and if it is a hit, they make back their money because you buy the reel of 15,000.

So we regular people could stand on the shoulders of giants but for one obstruction and that obstruction is soldering.

Soldering makes a metal-to-metal connection, nothing more than a bit of metal-to-metal logic. Now is the time to retire that connection to the Middle Ages.

That would have happened but for one little bug, one little fly in the ointment and that fly is capacitance.

Most of the time, capacitance is your friend. Want to smooth out the bumps in the road from power or switching? Install a capacitor. But when you want things to happen fast, capacitance puts on the brakes.

This bad kind of capacitance is aptly called parasitic. The solution is to use short or if possible, non-existent, wires.

One might say, "Why not cancel that capacitance with a little inductance? After all they ARE opposites aren’t they?" Well adding inductance to capacitance only throws gas on the fire when it comes to slowing things down because of one itty-bitty formula. Like its friend, E = mc², that formula is absolutely magical. It is (drum roll please):



Where L is inductance and C is capacitance. If you want to go fast, you have to make L and C small. The smaller you are, the faster you go until you aren’t there. Like Dylan said, "I'm glad I'm not who I am!" You’re traveling the speed of light, trading inductance for capacitance, in waves that shoot through space.

So what do I want already?

I want to be able to sit at my computer and design a circuit that uses a whiz-bang IC and then I want to click PRINT and have the circuit pattern ready to go. Then I want to GLUE the IC and other parts down to the metallic pattern printed on paper, fire it up and watch it blink or glow or do whatever it needs to.

And I don’t want the whole process of printing and gluing and firing it up to take more than 5 minutes, because that is really about as long as I can stand to wait.

And if I had that, I could make all kinds of things, like radios, and robots and glasses to see Dimension-N, just by printing and gluing and firing them up.

And I don’t want this just for me or my friend, I want it for everybody. I don’t want to build a million dollar lab and make a hundred thousand dollar machine.

I want a hundred dollar machine and two dollar glue.

Then I can live in a world that we can make a better and more interesting place.

Sunlight at the End of the Tunnel

Here is the performance of a certain solar cell company as seen from Google finance. Solar is up 1157% over a 34 month period. "Solar has tipped", to quote Malcolm Gladwell. I put this chart at the end before, but nobody reads that far anymore.

Sometimes I like to look at what the market is doing to see what collective wisdom is currently in force. This lets me see if what I’m thinking is what the rest of the world is thinking. I would just hate to be out of step. Here is a graph of fossil energy stocks for the past 34 months. Up about 50% on average. Not quite like solar.

Energy is in blue. US industry is in red. The value of energy is rising faster than the dollar or the value of industry. There are 334 energy companies. Over half, 186, of these companies are worth a billion dollars or more. One company, Exxon is worth half a trillion dollars. I took the time to add up their values. Their combined value is 4.13 trillion dollars. If you gave 4 million people a million dollars each, what might they do? At least be quiet, right?

Now let’s look at what the market says about coal. Maybe it will say, “"Say No to Coal"”, and we can take our yard signs down.

Nope. The market says coal is increasing in value more rapidly than gold. Here is gold over the same period:

There are 22 coal companies with a combined value of 103 billion dollars. One company, Peabody Energy is worth 21 billion dollars. Guess we better leave the yard signs up. But there is one piece of good news. Solar cells are rising faster than gold or coal or most anything. Over 1000% in the last two years. Don’t you wish you had been in that?

PC Security Checklist

As more activities migrate to personal computers, system security becomes a greater concern. Threats to PC security include viruses, Trojans, worms, phishing schemes, buried processes and distracting scams. This note is Wintel-centric but applies to Mac and Linux boxes as well. This note addresses five categories of personal computing security.

A) Physical and Site Security - Routers and Locks

The web connection coming into your house is just another sewer pipe. Treat it accordingly. Use a router, lock it down.

1) Avoid connecting your DSL or cable modem directly to your computer. Instead,isolate your IP address by placing a router between you and the outside world. This also gives you additional ports that you can control access to and from. A router makes it difficult for an outsider to see your IP address (your internet phone number) or your MAC address (your hardware unique identifiers).

2) Install your router where you can see it. Control physical access to it.

3) Change your router name and password to something besides admin, admin.

4) Change your router IP address to something other than 192,168.1.1. Your browser will remember the new address. The router address can be reset by rebooting your router, but not without physical access.

5) The internet is NOT ham radio. Goodwill, Character and Integrity do not apply as in the licensed arts. Use 128-bit WEP or better encryption. Any device that connects to my router (the internet equivalent of a repeater) must have permission.

B) Soft Security - Anti-virus Software

You can do everything right and still get infected.

1) Install good anti-virus software. I currently use McAfee because it comes free with my Scottrade account and I can run three legal copies of it on other computers in the household. I have used Norton, but it costs too much, expires frequently and hogs system resources. I really like the free AVG software. It is excellent and they don't try to elbow out everything else. Computer Associates gives you a free trial and then makes uninstalling a total nightmare. This goes for several other packages. If a vendor doesn't provide a clean uninstaller, don't use them, because THEY are a virus.

2) Use firewall software. Insert exceptions for required sites and services like Echolink.

C) Email Security

Scan inbound and outbound email and attachments using anti-virus software.

1) Don't open attachments from people you don't know.

2) Google gmail allows you to report items as spam. Use it.

3) Report fraud and phishing emails to their respective agencies including the ISP, Paypal, Ebay, FBI and Attorney General. Some ebay frauds have been really authentic looking. Check for spoof URL's before responding.

4) Keep a primary email account, and route all other email accounts to and
from it. This is for convenience as much as security.

D) Browser Security - Plug-ins and Spyware

Try Firefox 3.0 or later. It is multi-platform, open source, and accountable.

1) McAfee red lights troublesome web destinations, including bad ham radio destinations which are rare. I average 490 searches a month so this is quite handy. Other products also do this. Do not let anyone or anything obstruct your access to good information.

2) Don't use products (e.g. Real Video) that monopolize services such as video display and attempt to be the end all. If you give them your name and address you will get on "some list". Some lists go everywhere. Some programs will leave background processes running to report back to the mother ship. Besides invading your privacy these make browsing and computing slow.. AT&T Yahoo DSL is notorious about filling your PC with wasteful market-driven processes. They have destroyed the quality of many a newcomer's experience by marketing them to death. Too many choices.

3) Use Google Safe Search to avoid sites that are a frequent source of viruses. Your computer will get sick. It's karma.

4) Use Microsoft AntiSpyware. Forced by their own losses to develop this product, it works and its free. It is fairly lightweight, process-wise. Enable the auto-download, but require them to ask permission to install. Keep track of what they are adding or subtracting from your computer. Their track record requires them to be supervised.

5) Avoid illegal download sites for music, videos, or software. Your computer will get sick. More karma. Why steal? You will have to make a list like Earl.

E) Kid Security

"Little eyes, watch what you see..."

1) Put kid computers in a public place like the kitchen.

2) Check your kids browser history, chat, IM, Skype, often.

3) Facebook trumps myspace, but not by much. Check online friends and memberships often.

Conclusion

We live in the age of hot and cold running knowledge. Anything that obstructs access to this knowledge is a loss of freedom.

We also live in the wild west of the information age. Forewarned is forearmed.

L. Van Warren - AE5CC

Antenna Gain

Gain patterns can be drawn for microphones, radio antennas and light reflecting from surfaces. They are both informative and beautiful. The following images show the gain of a certain "wideband" herringbone antenna as frequency increases. Gain is simply the sensitivity of the antenna to a signal in a given direction.

When you tune a radio, you are selecting which frequency you want to listen to. But your antenna has to be cooperating by being sensitive to both the frequency of that station, its location, and how the signal bounces off the sky, land, water, trees, mountains and buildings.

So to begin we tune to 1.0 megahertz on our radio dial. In the pictures that follow we will increase the frequency on our radio dial by a factor of ten with each click. That makes for pretty big jumps. I hope to animate the in-between's soon. There are so many variables one must decide what to show first. In the meantime here is a keyframe warm-up starting at the promised 1 MHz. Captions are below the images.

You Say Tomato

1 MHz - Radially symmetric pattern, more gain at top than bottom.

I Say Potato

10 MHz -More gain at the ends than the middle.


The Edges of Lambda

100 MHz -Nature is more beautiful than I can imagine.

Butterfly Spectacular

1000 MHz -Think about this next time you tune a radio.

The last picture is around the frequency of cellphones and some cordless phones. But their antennas actually have blobby radiation patterns like the first example. Can you think why that might be so?

Copy Number Variation: The Next Big Thing

Copy number variation (CNV) is an important issue in genetics.

It has a beautiful mathematical notation suggestive of text processing:

Huntington’s chorea, produces dementia that does not appear till middle age. It is caused by the presense of too many CAG repeats. What was I saying? Oh yes:

CAG repeats involve three of the four DNA bases, Cytosine, Adenine and Guanine:

If there are too many CAG’s in succession on the short arm of chromosome 4, that individual will develop Huntington’s. Period. Unlike Huntington's, which is caused by repeats, there are other diseases caused by single point mutations. Recent genome studies have focused on these mutations, called SNP’s, and pronounced “snips”, which stands for Single Nucleotide Polymorphisms. This is a fancy word for one letter of DNA, being substituted for another. A bug in the code as it were.

If you live in a world like I do, where the internet is a connected series of pipes, here is how to cure someone of sickle cell anemia, a notable SNP-caused disease.

In a text editor, like “vi”, edit chromosome11.txt:

1)Find line containing beta-globin gene.

:/beta-globin

2)Code for glutamate instead of valine.

:s/GAG/GTG/

3) Save changes and exit file.

:wq

This single SNP is responsible for all human suffering in sickle cell anemia, but it also confers protection against malaria, so there is an up side.

Hemoglobin is the protein in red cells that enables oxygen transport from the lungs to the rest of the body. It tiles in four unit pillows called hemoglobin tetramers.

When the DNA recipe/gene that codes for hemoglobin is altered by a single letter, the hemoglobin forms rigid rods, polymerizing like plastic, which you can show is what people are made of.

This causes the red cells to look like a tent with a pole sticking in the wrong place. These red cells get stuck in capillaries and cause great suffering. But many diseases caused by SNP's have already been identified as such. SNP’s were the “low-hanging fruit” of discovery.

In the long term Copy Number Variation will turn out to be the next big thing, the next frontier. It is already yielding results. You heard it here first.

NOTES:
1 - Click here for more about CNV and on the images for background.
2 - One can observe an easier to parse notation for the first figure: ABCD, AB2CD, AB3CD, ABC4D3(CD), A(CB)D, the last being “inversion”.
3 - Database of Genomic Variants
4 - Visigene

That 20 minute delay.

Temporal correlation between Apple and market siblings.
(black bars show synchronization)

That little issue of the 20 minute delay in stock prices is a very interesting one.

I am interested in time, maps and relationships. My computer clocks are synchronized with network clocks that use atomic standards to keep accurate time.

The markets slid yesterday. I checked them first thing today to see how they would respond at opening. I was surprised to find that market reports that I thought were real time are not.

finance.google.com offers an interactive market graph.
As of 9:21 Eastern time, no data.

scottrade.com offers market data to subscribers, which I am,
As of 9:25, no data.

excite.com offers a thumbnail survey that claims a delay,
As of 9:30 Eastern time, no data. Curious.

Is there a twilight between market change, and the rest of the world finding out about it?

Does this delay provide an advantage to the real time trader?

The image above is from an exhaustive numerical analysis to determine the connectivity of various stocks.

Electronic signals travel at nearly the speed of light.

An electronic signal, as a stock price, can circle the earth 7500 times each second.

A fast video gamer can react in less than a tenth of a second.

A computer can react in about a microsecond.

I would wager, that until that 20 minute delay is removed, some people with access to real-time signals and computers will continue to profit exorbitantly off the losses of others.

In trading terms, a half hour is an eternity. It is the chasm between rich and poor, just and unjust, leading and following.

Apple vs. AMD tracking over a year.

Forte! The Loudest HF Radio Source

.


I finally got my program going for visualizing celestial radio sources. It was one of those stay-up-all-night-cause-its-too-exciting-to-sleep kinda deals. The push came at was the end of a week-long programming binge. Now its rehab time.


Here are some preliminary results, seen from several points of view. In these images, the size of the blob is the loudness of the source. The color of the blob is the spectral index. Purply blobs are blue-shifted "hot" sources. Orange-red blobs are red-shifted and thus cooler, in the radiant sense.


To give you a sense of this, here is Andromeda, by its lonesome:

Here it is hanging with its radio friends:


Some friends are louder than others:

Turns out this source is near a couple of black holes in the catalog.
One is "feasting" the other is "spewing". Quite the cosmic party.



I find that very exciting...

You can too. The Google Earth kml file may be downloaded here.

- Van

L. Van Warren MS CS, AE
web wdv.com
FCC AE License AE5CC

"Slow is Fast and Fast is Slow"

Third Rock: Get Your Galactic Freak On

Made some more progress getting the Ukranian RF data loaded into Google Earth.
Many of the glitches are gone and I am getting better coregistration.
Here is an example of a “possible” optical correlation with a radio source.
In galaxy zoo this would be classified as an elliptical galaxy. Perhaps it isn’t!


I still have to size the radio emitting sources by their flux, which is a little harder due to the grammar, but is coming into reach. There are a few really loud sources. I can’t wait to get my freak on them. But at 5:30 am, its probably time to go to sleep! This is so exciting, it is literally making me sick to my stomach. I am having a lot of anxiety with each step. This is very powerful stuff. Leverage. And it is so new. No eyes have ever seen this massive correlation.
Don’t know who to tell really, so you guys are it! I will release a layer soon and you can load it into Google Earth yourself!

All the red spots below are radio sources.



All the best,

- Van

L. Van Warren MS CS, AE
web wdv.com
FCC AE License AE5CC
Slow is Fast and Fast is Slow

Second Look: Visualizing Radio Sources

This evening's work consisted of rendering the sources as point emitters, instead of envelopes.

Here is the sky before and after visualizing radio sources:

Before:




and After:


The dark band appears to be a gap in the data.

Next tasks are to render sources by their strength or apparent radio brightness, and clear up gaps in the data.

- Van

First Light: Windows To A New View of Space

There is a saying in telescope construction: “First Light”.

It is at that moment when one finds out if all the work will have a reward. It can be so much work. Just now, while a retrospective of Pavaroti ran on CBS, my radio telescope mapping program got its first light. I am visualizing the Ukrainian UTR-2 Radio Source Catalog.

Here are two pictures showing the sky as we used to see it, and the radio sky as we can now see it. This is very rough, and maybe even wrong, but it shows that all the pieces can talk to each other, and that is the hard part.

Here is what the sky looked like before:

Here is “after” the first light. Each red window is a radio source. I promise to improve this, but it’s a start. There are 12,000 observations from over 2000 galaxies, quasars and galaxy clusters emitting on frequencies you can hear on a short wave radio 10 – 25 MHz. Hopefully we can do that too!

It is so exciting! Thanks to all the astronomers in the Ukraine and the engineers at Google who made my work visualizing the UTR-2 catalog possible.

Rosette Nebulae with Ukraine 10-20 Mhz Radio Windows

Zero Point: Visualizing 16.7 MHz Celestial Radio Sources:

This evening was spent processing the Ukraine Russia Radio Telescope Database and extracting celestial coordinates, spectra and signal strengths for 16.7 MHz RF Celestial RF Emitters. Results were obtained for the following numbers of objects:

Quasars: 118
Galaxies: 142
Galaxy Clusters: 15

Subtotal: 275

Other Grade A Emitters: 749 // high quality measurements
Other Grade B Emitters: 596 // medium quality
Other Grade C Emitters: 510 // lower quality

Subtotal: 1855

Grand Total: 2130 celestial radio sources

This required many computational operations, data verification and conversion passes. Scripts were written that convert the raw catalog into a consistent, normalized and usable form.

Now that the database is ready, I intend to plot these radio sources in Google Sky so we can “see” their distribution and galactic neighborhoods. M31, Andromeda, is my focal point, but I’m very excited to have many sources to consider. Color=Frequency, Size=PointingRolloff, Brightness=Flux. It will take me a few days to produce the KML channel. Unix makes cleaning and sifting through the data much easier. This will help us know where to point our software radio antennas. Wish me luck.

A Switched Variable Capacitor

Lately I have renewed my interest in wideband radio. The question is, what is possible now?

Turns out, it’s all in the amplifier.

Texas instruments makes a very interesting wideband radio frequency (RF) amplifier. It is called the THS3202. There is a saying in radio, “DC to daylight” to describe this kind of part. The 3202 goes from 100 kHz to 2 GHz, not quite daylight, but pretty close.

THS3202 Wideband RF Amplifier -- Texas Instruments

That is sixty-five times more bandwidth than the Hammarlund of the previous article. That’s a lot. The 3202 weighs much less than a gram. That’s a little. You can see it in the center of the board above.

Here is a circuit showing the THS3202 in action:

3202 Amplifier in Action -- Bruce Carter TI

Finding the Needle in the Haystack

There are three ways of teasing a given signal out of the haystack of broadcasting and noise.

1) Resonate incoming RF through LC tank circuit to select a specific signal.

2) Multiply all incoming RF by a frequency you choose and generate.

3) Bandpass filter all incoming RF to amplify the desired frequencies and quench the rest.

Most radios use methods 1 and 2, heterodyning to demodulate the incoming signal. Here we focus on method 3, homodyning, made possible by advances in amplifier technology...

Filtering

Trump, Stitt and Bishop of Texas Instruments have created a program called FilterPro™ that enables the accurate specification of filter banks for a wide range of frequencies. Low-Pass, High‑Pass and Band-Pass filters can be designed using Butterworth, Bessel, Chebychev and other common filter paradigms. FilterPro™ allows cascading stages of bandpass filtering that use identical components, except for the filter capacitors. As a quick example, consider the following two­‑ pole filter centered at 500 MHz:

Two Pole Bandpass Filter created using FilterPro™

An iterated use of the program produces the following range of component values in a five-pole bandpass filter:

Capacitor Values Required for Wideband Filter Tuner

Capacitor Values Required for Wideband Filter Tuner

Five stages of the filter shown above enables a very wideband filter to be created that can serve as a radio tuner. From the graph we can see that the bandpass filter not only filters, it amplifies the signal of interest by 40 decibels (dB), or a factor of 10,000.

A Switched Variable Capacitor

“Back in the day” variable capacitors with consecutive ganged stages were used to address the tuning problem. They looked like this:

Air Variable Capacitor from Wikipedia

Modern versions of such capacitors have a range of capacitance from 15 picofarads to 384 pF. Synchronizing 10 instances of 15000 pF each would require 390 such units.

The trouble is that for each section of our five pole bandpass filter, we required two capacitors whose values can range from 1 pF to 15000 pF, that is, five decades of variation. A coordinated five pole array requires ten wideband variable capacitors operating in near-perfect unison. Accomplishing this with combinations of mechanically ganged variable capacitors is not practical.

This paper explores the creation of a variable wideband capacitor constructed using arrays of surface mount capacitors and solid state relays.

Novacap Capacitors and Teledyne RF Relay

The questions are:

· What topology of array?

· What form of switching?

A useful design would require.

Clearly the equivalent series resistance (ESR) of the switched capacitor should be as low as possible to maintain the idealized properties of a capacitor.

Two solutions come to mind. Both give rise to interesting mathematical analysis. We will start with the simplest first.

Note” The term “array” will be used to talk about the ensemble of capacitors used to create a single variable wideband capacitor. The term “bank” will be used to talk about a synchronized set of such variable wideband capacitors.

Point of Clarification

A Simple Decade Array

Consider an abacus like arrangement:

A Switched Variable Capacitor from 0 – 99,999 pF with 1 pF Steps

This capacitor would require 5 columns for each of the five decades. Each column would require 9 capacitors to represent the digits in each decade. The result would be a variable capacitor of 0 – 99,999 pF in 1 pF steps. Now obviously lead capacitance would make absolute values below 5 pF difficult to obtain, but increments of 1 pF could be realized with this device. This bank requires 45 capacitors and 45 switches to accomplish this task. With surface mount technology it would be the size of a postage stamp.

The question is finding those values of capacitance.