Saturday, May 30, 2009
Sunday, May 24, 2009
The Jupiter image is false-color near IR data obtained with the LEISA instrument, built at GSFC.
I try to always read the QRP-L postings of NA5N -- Paul always has something interesting in his messages. Today I found this:
Jupiter emissions peak around 18-22MHz; they are a function of when the moon Io crosses certain longitudes of the relatively fast spinning Jupiter. There used to be a couple of calculators online (haven't checked lately) as to when the L-bursts should occur. The timing is quite predictable; detecting them on every predicted occurrence is not. You have to have an antenna with a little bit of gain. The signals are generally weaker (that is, near the atmospheric noise level) than can be detected with a dipole. With a fairly decent setup, the Jovian L-bursts sounds like ocean waves crashing on a distant beach, just barely above the noise level. The S-bursts sounds like random pulse type static in short bursts. These are harder to detect than the L-bursts.
I had known about the Jovian radio emissions, but I didn't know that the moon Io was involved. For me, Io's involvement somehow makes this even more interesting. Jupiter and its moons (including Io) are some of the few celestial objects I can regularly see from central Rome.
Here is a good description of Jupiter's radio signals, and Io's role in transmitting them:
And here is an interesting article about the discovery (50 years ago) of these signals:
In SolderSmoke 108:
May 24, 2009
WSPR: W3PM sees my sigs, back to visual (briefly), on to Slow Hell.
Ubuntu ham radio software
gets his Class A license
"SolderSmoke -- The Book" Good for summer vacation reading.
SPECIAL REPORT FROM DAYTON - FDIM BY BOB W8SX
CHECK OUT THE BOOK: (First chapter preview available)
Friday, May 22, 2009
Later, in describing the keying device, Henry wrote: " The surface of the saw blade was coated with several layers of spray paint, which served as insulation, preventing the bobby pins from contacting the metal blade. The message was programmed on the blade by carefully etching through the paint. "
OK, that does it. Time for me to go back to the Trastevere flea market to pick up some more cheap clock drives... and maybe some circular saw blades. I need to get going on my mechanical QRSS one-transistor becaon project.
Wednesday, May 20, 2009
After reading this I was feeling like a complete APPLIANCE OPERATOR. But wait a second Russ -- that's a KIT! Real homebrewers don't need KITS to make their own crystals! And remember, you are talking to a guy who has used iron pyrite and a phosphor bronze to detect radio waves. That means I have homebrewed my own DIODES! ;-)
Thanks for the cool pictures Russ. Those were the days...
Graham, G3ZOD, sent me this WSPR screen-shot. He writes:
Hi Bill. Thought you might be interested in a screen grab of yourself. You're the near continuous signal along the centre of the waterfall just below 200 on the vertical axis.Not DX from Italy to England, but I'm using an indoor wire antenna and I usually receive you for short periods only - never seen such a consistent signal before. By the way: I think your computer clock may be a couple of seconds off according to the DT values; I have mine resync every 6 hours and my clock is generally within 150 milliseconds.
73 de Graham G3ZOD
Thanks Graham! The consistency of my signal is no doubt due to the fact that I have no receive system here yet, so on the WSPR software, in the "T/R Cycle" box I had "TX" checked. So I was "key down" most of the time. Your screen shot made me realize that this might not be the most neighborly thing to do -- someone else on the same freq might be QRMd by my 20 mW DSB sig. So I think I'll ratchet down the T/R cycle here.
My computer clock is erratic. I have to tweak it each day. I know there is a program out there that automates this -- haven't gotten to that yet. 73 From Rome
Tuesday, May 19, 2009
Monday, May 18, 2009
I was drifting off into Linux-land, but an e-mail from OM Gene, K8EE, brought me back. I'd thought that we had already unearthed all of the best ham radio episodes of the Jean Shepherd shows. WRONG! K8EE sent me YouTube recordings of the January 7, 1964 show on WOR New York. Gents, all I can say is that you should stop what you are doing, and listen to this. (And don't miss the exciting conclusion in part 2!)
"Mr. Rupp, what do you know about the Mu of an '807?" Indeed.
4.10 Warty Warthog
5.04 Hoary Hedgehog
5.10 Breezy Badger
6.06 Dapper Drake
6.10 Edgy Eft
7.04 Feisty Fawn
7.10 Gutsy Gibbon
8.04 Hardy Heron
8.10 Intrepid Ibex
9.04 Jaunty Jackalope
9.10 Karmic Koala (NEXT ONE) October 2009
OK, now back to the radios...
Sunday, May 17, 2009
Believe it or not, I have never built anything Manhattan style… So, I decided to give it a go and built a little 40m DC receiver designed by Rev. George Dobbs G3RJV consisting of a NE612 and LM386. I have included a shot of it below. I was very pleased with this building style and think I may adopt it going forward. In particular I like how easy it is to make changes. I just used tin snips to make the pads. For the 8 pin IC pads, I cut them 2 cm square and used a hacksaw to saw between the IC pins and up the middle to separate the pin pads electrically by removing the copper. Make sense? Very simple to then bend the IC pins 90 degrees and solder them down. Preaching to choir, I know… But it takes some us a little longer to get on board, eh? J I was very pleased with the outcome.
I like Jeff's technique for the IC pads. I will have to try that.
SolderSmoke 108 will feature an interview with George Dobbs in which he talks about the Sudden Build-a-thon.
Hi Bill, I just wanted to let you know that I hear your 20 mW WSPR signal each morning around 0500 to 0700 UTC. Your signal strength varies between -21 and -26 dBm.
I am currently on vacation in (GM4YRE, IO86ru), Scotland which is located about 30 miles SW of Aberdeen in the northeastern part of Scotland. I have very limited internet access; therefore, I cannot report WSPR spots in real time. My WSPR transmitter is active most days on 30 meters until we leave Scotland... I run one watt to a low doublet antenna.
73/72 Gene W3PM GM4YRE
Saturday, May 16, 2009
Friday, May 15, 2009
NASA put together a video on the personal stories of the crew members. I think it is a good thing to show kids (Billy has already seen it, Maria is next):
Thursday, May 14, 2009
Here is the NASA description of the repairs.
Two of Hubble's instruments are in need of repair. ACS, which partially stopped working in 2007 due to an electrical short, is the "workhorse camera" responsible for some of Hubble's most spectacular images. STIS is a spectrograph that sees ultraviolet, visible and near-infrared light, and is known for its ability to hunt black holes. While COS works best with small sources of light, such as stars or quasars, STIS can map out larger objects like galaxies. STIS suffered a power failure in 2004 and was put into hibernation to preserve the possibility of its repair.
Astronauts plan to fix both – a challenging prospect since these repairs are beyond the scope of Hubble’s serviceable design. Hubble’s creators envisioned astronauts swapping out components, not performing delicate surgeries during spacewalks.
An interior electronics box of ACS that supplies power for ACS detectors, contains equipment affected by an electrical short. However, its location makes it inaccessible to astronauts. So instead of trying to reach the problem area, astronauts will attempt to bypass those power-shorted components entirely.
The failed power supply is connected by cables to a series of electronics boards, which are within reach but have no power because of the damaged box. Astronauts will install a new power supply to a handrail on the ACS outer enclosure, remove the electronics boards and install different ones that are compatible with the new power supply, and connect them to the new supply with exterior cables. The arrangement simply cuts the damaged box out of the equation.
Innovative tools for the repairs are designed and developed by Goddard engineers and tested by the astronauts for refinements. STIS needs a new power supply circuit board. The repair would be relatively easy but for the electronics access panel, which was never meant to be opened and is attached to STIS by 111 small screws. The screws are hard to grasp with the astronauts' gloved hands, and could create problems if they were to escape and float around the electronics. So engineers have created a "fastener capture plate" that fits over the top of the panel. When the astronauts remove the screws, they will be trapped in the plate. Astronauts will then switch out the power supply circuit board and close off the open electronics with a new, simpler panel that attaches easily with two levers.
Wednesday, May 13, 2009
He may not know it, but this dude has a bad case of The Knack. From his web sites:
In September 2005 the kids and I took several very accurate cesium atomic clocks from home and parked 5400 feet up Mt Rainier (the volcano near Seattle) for a full two days. The goal was to see if the clocks actually gained time, even if billionths of a second, as predicted by Einstein's general theory of relativity. Does gravity really alter time and can this weird phenomenon be detected with a family road trip experiment?
Ten years ago I wanted to build a LED digital analog clock that would be accurate to better than one second per year -- so I would have the fun of adjusting it when a leap second occurred. This simple goal resulted in a most interesting journey into electronics, horology, astronomy, test equipment, quartz oscillators, rubidium and cesium atomic clocks, hydrogen masers, frequency counters and phase comparators, GPS, Loran C, GOES, and WWV / WWVB radio receivers. That makes me one of the Time-Nuts. By now I've exceeded that goal by a factor of a million: the best clocks in my collection (active hydrogen masers) are accurate to better than one microsecond per year. Excluding national government laboratories, my home time lab now has the most accurate clock in the world.For info on the Rainier Time Dilation Road Trip: http://www.leapsecond.com/great2005/tour/
For a more general discussion of this madness: http://www.leapsecond.com/
Hey, but who are we to talk, right?
Monday, May 11, 2009
On SolderSmoke 107:
SolderSmoke -- The Book! ON SALE NOW!
Get it here: SolderSmoke: A Global Adventure in Radio Electronics
Orbits II reborn via a VK6 junkbox
NA5N's Amazing Atlanticon 2002 article
20 mw across the Atlantic.
K1JT picks up my sigs
WSPR generates interest on Hack-A-Day
Linux: Ubuntu gets SolderSmoke Thumbs-up
Somerset Supper Report
Diode Ring Mixers
AA1TJ, Chloroform, and HB transistors
Have fun at FDIM!
Saturday, May 9, 2009
electronics. Bill Meara started out as a normal kid, from a normal
American town. But around the age of 12, he got interested in
electronics, and he has never been the same.
To make matters worse, when he got older he became a diplomat. His
work has taken him to Panama, Honduras, El Salvador, the Spanish Basque
Country, the Dominican Republic, the Azores islands of Portugal,
London, and, most recently, Rome. In almost all of these places his
addiction to electronics caused him to seek out like-minded radio
fiends, to stay up late into the night working on strange projects, and
to build embarrassingly large antennas above innocent foreign
neighborhoods. SolderSmoke takes you into the basement workshops and
electronics parts stores of these exotic foreign places, and lets you
experience the life of an expatriate geek. If you are looking for
restaurant or hotel recommendations, look elsewhere. But if you need to
know where to get an RF choke re-wound in Santo Domingo, SolderSmoke is the book for you.
SolderSmoke is no ordinary memoir. It is a technical memoir. Each
chapter contains descriptions of Bill’s struggles to understand (really
understand) radio-electronic theory. Why does P=IE? Do holes really
flow through transistors? What is a radio wave? How does a frequency
mixer produce sum and difference frequencies? If these are the kinds
of questions that keep you up at night, this book is for you.
Finally, SolderSmoke is about brotherhood. International,
cross-border brotherhood. Through the SolderSmoke podcast we have
discovered that all around the world, in countries as different as
Sudan and Switzerland, there are geeks just like us, guys with
essentially the same story, guys who got interested in radio and
electronics as teenagers, and who have stuck with it ever since. Our
technical addiction gives us something in common, something that
transcends national differences. And our electronics gives us the means
to communicate. United by a common interest in radio, and drawn closer
together by means of the internet, we form an “International
Brotherhood of Electronic Wizards.”
Friday, May 8, 2009
Hey, I found a Yahoo Group of kindred spirits late last night, 2N1150_Down; where the interest is centered on early Germanium semiconductor devices. I downloaded a book from their files that, until now, I'd only heard about. Practical Transistors and Transistor Circuits, by J.S. Kendall, first appeared in the U.K. in 1954. Believe it or not, the subject of the book is how to make the "practical" transistors referred to in his title! Of course, these are point-contact devices built from a pair of cat's whiskers on a slab of "P-type" Germanium salvaged from diodes. I especially like where he writes, "Great care should be exercised owning to the anesthetic properties of the chloroform vapour...the constructor may not be aware of the danger until he is almost on the point of collapse." Oh brother!
Better yet, I found an article in the group's files taken from the March and April, 1954 issues of The Short Wave Magazine, by G3HMO. This fellow not only made his own transistor, he used it to build a one-transistor, 160m, transmitter and then went on to make contacts with it up to a distance of 30miles! He writes, "There is nothing impractical about making a point-contact transistor at home." Oh baby, crack me open a bottle of chloroform and let's get to it!
The photo above is, of course, the original point contact transistor from 1947. It looks do-able.
In searching for the picture I came across this interesting article from the author of the wonderful book on this subject "Crystal Fire" : "How Europe missed the Transistor"
Thursday, May 7, 2009
The NASA stereo images were nice, but the amazing picture above was taken from a backyard in Buffalo, New York by solar photographer Alan Friedman.
It seems like the effects of this new prominence will be felt here on earth on May 8. Woo Hooo! Maybe my WSPR signal will cross new oceans!
Wednesday, May 6, 2009
I came across Thomas's very interesting web site when I was installing in my QRSS beacon rig the SBL-1 mixer sent to me by Jim, AL7RV. That poor SBL had died suddenly during testing. Thomas alerted me to the cause of death: In his caption for the picture of the innards, he notes, "I was unlucky to kill this one during my first transmit experiment. The IF input can NOT accept more than +20dBm audio level."
Joop and I have been discussing diode ring mixers, and I've been reading an article about them by Paul, NA5N. It looks to me like the designers of the SBL mixers weren't really thinking of balanced modulators when they created these things. Just look at the schematic above. In a normal receiver application, LO energy goes in from the L port, your RF goes in R, and your IF (or, in a DC receiver, your AF) comes out from the I port. But when we use these things as balanced modulators, we have to put the Audio INTO the I port. You can see how too much voltage on that port would quickly release the smoke from those little hot-carrier diodes.
The data sheets are oriented to the standard application (RF into R, LO into L, IF output at I). We are told to keep the LO level at +7dBm and that the 1 db compression point for the RF input is +1dBm. But at what level should you put the AF input to the I port if you are using this thing as a balanced modulator in a weird WSPR DSB rig? Similarly, the data sheets give SWR data across a wide frequency range for the L and R ports... but not for the I port. DSB is getting dissed!
Sunday, May 3, 2009
|2009-05-03 16:42||N2CQR|| ||-29|| ||K1JT||7035||4371|
|2009-05-03 16:38||N2CQR|| ||-24|| ||K1JT||7035|| 4371|
I got into WSPR because I wanted the gratification that comes from seeing a map readout indicating that my QRP signal has crossed various oceans. Well, yesterday I crossed the pond for a second time, but this time the receiving station heard the signal more than once, so the rx station callsign appeared on the display (if the signal is heard only once, you get the line showing the path, but NOT the rx station call). And what a fine callsign it was: K1JT, Joe Taylor, Nobel Prize winner and the inventor of WSPR.
In the last SolderSmoke I got Joe's name wrong (I called him John). It must have been too early in the morning here. Anyway, I was gently corrected by Wes, W7ZOI, and I promissed to make ammends. Sorry Joe! (Thanks Wes).
Friday, May 1, 2009
Above, in the foreground, Merv checks the main board of his softrock, Ian explains to Paul how a mod to an old FT101ZD will work, and Nigel is seen using the microscope and observe to Merv he has not soldered all the IC legs down on a SMD board. He says he knows. grin!!
Ian Keyser, G3ROO, host of Dover Construction Club. At his bench in a separate part of the workshop where he has test equipment to diagnose the inevitable faults. Here he is working on the RAMU featured in a past edition of Sprat.
In a corner of the garden a brick arch leads to the workshop door, behind the brown door hides the secret world of the amateur radio constructor. Obviously, this is something of a clandestine operation.
Tony, sitting at the other end of Ian's test area, taking down some CW.
In this workshop club members have bandsaw, milling machine, lathe, and pillar drill.
Wow! That's the kind of club that we'd all like to be part of -- Nigel's comments on SS 104 generated a lot of envious e-mail . Thanks a lot guys!