Farhan alerted us to this. From the NASA website:
April 1, 2009: The sunspot cycle is behaving a little like the stock market. Just when you think it has hit bottom, it goes even lower.
2008 was a bear. There were no sunspots observed on 266 of the year's 366 days (73%). To find a year with more blank suns, you have to go all the way back to 1913, which had 311 spotless days: plot. Prompted by these numbers, some observers suggested that the solar cycle had hit bottom in 2008.
Maybe not. Sunspot counts for 2009 have dropped even lower. As of March 31st, there were no sunspots on 78 of the year's 90 days (87%).
It adds up to one inescapable conclusion: "We're experiencing a very deep solar minimum," says solar physicist Dean Pesnell of the Goddard Space Flight Center.
"This is the quietest sun we've seen in almost a century," agrees sunspot expert David Hathaway of the Marshall Space Flight Center.
For the rest of the article:
http://science.nasa.gov/headlines/y2009/01apr_deepsolarminimum.htm?list830785
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Thursday, April 2, 2009
The Siren Song of WSPR...WSPR DSB?
Man, that's the kind of map that I want to find on the screen when I walk into the shack in the morning. Or maybe on my Blackberry at lunchtime. Above you can see the WSPR spots for Jeff, KO7M. You can see Jerry, NR5A, in there, proudly representing South Dakota. Buried under the Northeast calls is K1JT, the only Nobel Prize winner in the group.
This morning I downloaded K1JT's WSPR program and was very pleased to find that it runs nicely on this old, rickety Windows 2000 machine. (I pushed the envelope a bit and tried to get it to run on my recently revived Toshiba Satellite Pro 400CS, but it didn't seem to like Windows 3.1. ) I have on the workbench the plans for W3PM's bare bones WSPR transceiver and the WSPR care package sent over by Jim AL7RV.
Here is my plan: Make W3PM's rig even simpler. TX only (at first) and Double Sideband. Maybe I'll just put an SBL-1 mixer between the oscillator and the RF amp in my current Visual MEPT transmitter. (I'll make it switchable so that I can go back to our beloved visual mode whenever I want.) Then add W3PM's audio amplifiers between line out on the sound card and the audio input port on the SBL-1.
What do you guys think? WSPR DSB? The other sideband should fall FAR outside the band, and it will almost certainly be completely down in the noise for anyone not running ARGO or SPECTRAN-like software.
This morning I downloaded K1JT's WSPR program and was very pleased to find that it runs nicely on this old, rickety Windows 2000 machine. (I pushed the envelope a bit and tried to get it to run on my recently revived Toshiba Satellite Pro 400CS, but it didn't seem to like Windows 3.1. ) I have on the workbench the plans for W3PM's bare bones WSPR transceiver and the WSPR care package sent over by Jim AL7RV.
Here is my plan: Make W3PM's rig even simpler. TX only (at first) and Double Sideband. Maybe I'll just put an SBL-1 mixer between the oscillator and the RF amp in my current Visual MEPT transmitter. (I'll make it switchable so that I can go back to our beloved visual mode whenever I want.) Then add W3PM's audio amplifiers between line out on the sound card and the audio input port on the SBL-1.
What do you guys think? WSPR DSB? The other sideband should fall FAR outside the band, and it will almost certainly be completely down in the noise for anyone not running ARGO or SPECTRAN-like software.
Labels:
WSPR
Tuesday, March 31, 2009
Amazing NASA site: Audio from Apollo Landings
Akshay, VA7AAX, sent me a link to a truly amazing site. NASA has pulled together a huge amount of data on all the moon landings, and they have made it very accessible. Included is a LOT of the raw audio of the communication between the spacecraft and ground. They even have the internal communications inside the lunar lander. If you guys are looking for something to put in your MP3 players (in addition to SolderSmoke, of course) this is the place to go. It is also a great site for audio to be played in the shack while building something. It is really inspiring. This morning I listened to the Apollo 11 landing.
I like the live.365 system for the audio -- you can listen to it in streaming mode, without waiting for a long download.
Here is the site:
http://www.hq.nasa.gov/alsj/frame.html
Thanks Akshay! Thanks NASA!
I like the live.365 system for the audio -- you can listen to it in streaming mode, without waiting for a long download.
Here is the site:
http://www.hq.nasa.gov/alsj/frame.html
Thanks Akshay! Thanks NASA!
Labels:
space program
Sunday, March 29, 2009
SolderSmoke Podcast #104
http://www.soldersmoke.com
1 April 2009
Rome Marathon
Billy climbs Vesuvius!
Fixin' up old Toshiba laptop
Solar Power from Donuts and Tea!
Eldon's MEPT ET Phone home machine
More Catalan minimalism: The MOSquito
Book: Thunderstruck! Marconi history
SPECIAL ECHOLINK QSO WITH NIGEL, M0NDE
MAILBAG:
Paul M0XPD new homebrewer, Funster 40, Paraset, and SDR
Preston WJ2V on REAL solder vacuum pumps
Ted AA5CK keys MEPT with iduino
Ken KG6PO on obit of TV pioneer Thomas T. Goldsmith
Art W2HQQ: "Man of High Fidelity" lacks knack
Scott KD5NJR on Sputnik 4, NASA comms
Alan W2AEW Don't smother MEPT oscillators! Books
Steve GOFUW Old Book recommendation. Building WARC rig
Jacki (XYL of KL7R) says hello from volcanic Alaska
Jeff KO7M Why FSK on QRSS?
Jim AL7RV Sends WSPR care package. (Thanks!)
Labels:
SolderSmoke Podcast
Solder Smoke Cologne! New!
As mentioned in SolderSmoke 104. Check it out! Here is the link:
Solder Smoke -- From the Men at Work Collection
Saturday, March 28, 2009
Troubleshooting and Simulations
Alan, W2AEW, roams the Northeast USA as a Field Application Engineer for Tektronix. This week he sent me an e-mail with some words of wisdom about simulations and troubleshooting. Thanks Alan!
An excerpt from Alan's e-mail:
Funny you mentioned about LTSpice, and wanting to have that puff of soldersmoke whenever you place a component. It reminds me of something that I'd often tell new-hire engineers. Many times, engineers fresh out of school have never touched a resistor - they've often spent their entire education doing bookwork and simulations. I would always caution engineers about this, and try to illustrate that the simulation is only as good as the model you give it. If you ask the simulator to exercise the model in a way it wasn't designed for, it won't tell you that, it will just lie to you. YOU have to be smart enough to recognize the lie. For example, the simulator has no problem putting 10,000 amps through a 1N914A diode - it doesn't know that you'll let the smoke out of it! The simulator must be considered a tool, just as you VOM, scope, counter, finger, nose, etc. are all tools. Each can give you valuable information (and can lie to you). You have to learn to know what you can believe, and what you have to question - and you need to develop ways to look at strange behavior in a number of ways to figure out what is happening.
An excerpt from Alan's e-mail:
Funny you mentioned about LTSpice, and wanting to have that puff of soldersmoke whenever you place a component. It reminds me of something that I'd often tell new-hire engineers. Many times, engineers fresh out of school have never touched a resistor - they've often spent their entire education doing bookwork and simulations. I would always caution engineers about this, and try to illustrate that the simulation is only as good as the model you give it. If you ask the simulator to exercise the model in a way it wasn't designed for, it won't tell you that, it will just lie to you. YOU have to be smart enough to recognize the lie. For example, the simulator has no problem putting 10,000 amps through a 1N914A diode - it doesn't know that you'll let the smoke out of it! The simulator must be considered a tool, just as you VOM, scope, counter, finger, nose, etc. are all tools. Each can give you valuable information (and can lie to you). You have to learn to know what you can believe, and what you have to question - and you need to develop ways to look at strange behavior in a number of ways to figure out what is happening.
It reminds me of a story that Jim Williams wrote many years ago (you mentioned Jim Williams in a previous SS episode). He described how, as a child, he was playing with circuits at his neighbor's, and using his (neighbor's) oscilloscope to examine a circuit he was working on. He was getting all kinds of strange behavior, and couldn't make heads or tails of what he was seeing with the scope, VOM, etc. The neighbor (who was definitely afflicted with the Knack) came by and, with moistened fingers, probed around in his circuit for a few minutes. He then grabbed a small value capacitor and soldered it judiciously in the circuit, and everything worked fine. Jim was flabergasted and demanded an explanation. The neighbor said that he suspected that the circuit was oscillating at several hundred MHz, and used his finger's capacitance/loss/etc. to damp this behavior. He continued to explain that since the oscillation frequency was so high, the scope couldn't "see" it. Jim complained that this "wasn't fair"! The neighbor concluded the lesson about how important it is to not-only understand what our tools can do for us, but it is really more important to understand their limitations - because it is when we ask a tool to do something that it can't do, it often won't complain, it will lie. The same holds true for nearly every tool we use, and is a lesson well learned. This story is included in his chapter entitled "Should Ohm's Law Be Repealed?" in his book, "Analog Circuit Design: Art, Science and Personalities" from 1991.
Alan has a lot of great stuff on his web site. Check it out:
http://www.qsl.net/w2aew/
Alan has a lot of great stuff on his web site. Check it out:
http://www.qsl.net/w2aew/
Labels:
LtSpice,
troubleshooting,
Williams -- Jim
Friday, March 27, 2009
Marconi's Big Ears
Thunderstruck by Erik Larson has countless gems about Marconi. I thought I would share one with you this morning.
When Marconi was born on April 25 1874, an elderly gardener saw the new baby and exclaimed, "Che orecchi grandi ha!" ("What big ears he has!") Marconi's ever protective Irish Mom, Annie, took offense and replied:
Indeed.
When Marconi was born on April 25 1874, an elderly gardener saw the new baby and exclaimed, "Che orecchi grandi ha!" ("What big ears he has!") Marconi's ever protective Irish Mom, Annie, took offense and replied:
"He will be able to hear the still, small voice of the air."
Indeed.
Labels:
radio history
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