While reading up on the Broken Window Fallacy, I found this interesting article:

Economics in One Lesson

Briefly put, the Broken Window Fallacy is that when a boy tosses a ball through a window, he’s actually committing an altruistic act for society: since the shopkeeper with the broken window will have to hire a glazier to come and repair the window, and the glazier will buy bread from the baker, and the baker will buy…. there is an entire cascade of commerce and employment that happens as the result of this apparently destructive act.

Of course, this is a fallacy because it ignores the direct cost to the shopkeeper. If he didn’t have to repair his window, he could spend that money to satisfy his other needs. The article above explains this all plainly and in a reasonable way.

Earlier today, I was tuned into 30m listening for the the DXpedition to the Clipperton Atoll, transmitting using the callsign TX5C. The signals to there were really quite odd, they were characterized by deep fades, with the band going fairly quiet, then a few loud morse stations swelling up, and then suddenly a huge chorus of Morse signals swelling up, then falling into a deep, rapid fade.

I recorded a bit of it for you to listen to.

I spent a little time this morning moving my 20m dipole up a bit higher (to no noticeable effect) but then did start getting some SSTV images from 20m. Here’s the first one I received:

I was using the MacRobot SSTV program.

Well, I didn’t record this off the air, but I did take the raw data from the NOAA 18 weather satellite (more on how to get this later), and converted it into a jpeg using a program of my own devising.

Addendum: The NOAA data contains five different channels of data. This one looks pretty good too, makes the earth stand out more. (Eventually, I’ll figure out what these things actually all are, but for now… look, pictures!)

Nifty.

I was just scanning around the bands when I got home from work, and tuned up 30m, the amateur band between 10.100Mhz and 10.150Mhz. I heard some voice on 10.126, which is odd, since the band is dedicated entirely to Morse and data transmissions. What was even odder: it consisted entirely of a woman repeating digits. I had discovered my first numbers station:

Numbers station – Wikipedia, the free encyclopedia

Here’s a brief recording!

Wacky!

VE7BPB was telling KC9MUC how to make a quickie 6m dipole out of a chunk of coax on the irc #amsat channel. I don’t think (inexperienced ham that I am) that I had ever seen this exact technique before. Digging around, I found link to the method on the web, so I won’t have to transcribe the steps here.

Bob Simpleton’s Guide to Quickie Antennas

I didn’t hold high hopes for the NOAA 15 pass tonight, but the combination of the late evening twilight and the nearly overhead pass made a pretty nice looking pass.

Pretty nifty, I think.

Addendum: The above image appears pretty dark, so I cut out just the visible light portion of it, rescaled the brightness ina a completely arbitrary way, and did some median filtering to remove some of the spot noise.

With all the pondering of satellites that I’ve been doing lately, it seems inevitable that I would have to develop some interest in rocketry. Here’s a link to get you all started down the same path:

Association Of Rocket Mavericks

Got stomped. Oh well.

AO-51 Pass, February 23, 2008

Addendum: N3CRT tried to record it too. His recording is here.

I’m a teeny bit confused. The strong source of HF-FAX transmissions that i’ve been recording and decoding is broadcasting at night on 8.502 Mhz. I thought (based upon some link i can no longer find) that the transmissions were coming from Australia. But this website which has a list of HF-FAX transmitters suggests that it’s coming from Norfolk, VA.

There seems to be some genuine confusion. But for now, I’m going to assume it’s Norfolk, not Australia.

Addendum: Or, maybe, it’s the USCG in New Orleans. Sigh. In a way, that makes sense, because every map I seem to be getting shows the ocean off the Gulf of Mexico. It also matches up with this info from the USCG, which lists NMG as broadcasting on 8503.9, which means that I tune it on 8502.

Addendum²: Yep, it looks like New Orleans is where it’s at. Here’s a link to the schedule.. I’ve been doing my experiments around 11:00PM local, which is 07:00UTC. According to this schedule, at 07:25UTC, they rebroadcast the 72 hr surface forecast, which matches up nicely with what I received.

Addendum³: Here’s a GOES IR image from New Orleans.

Addendum⁴: Here’s the same image, in the pristine form you can get from the NOAA website:

One of the greatest science fiction movie of all time is without doubt the 1956 classic Forbidden Planet. One of the reasons it was so successful was the oddly futuristic electronic music of Louse and Bebe Barron, true pioneers in electronic music. What’s really odd is that NASA’s latest recording of radio signals from the Cassini probe around Saturn sounds remarkably like that music. Check it out:

Radio sounds from Saturn

Addendum: I’m apparently not the only one who noticed the striking similarity.

Thanks to Mark, WA8SME for calling my attention to this.

Addendum: Here’s the spectrum of the sounds over time (going left to right in time, up in frequency).

Kind of trippy.

Worked a bit more on the code. It now sets the appropriate horizontal size and aspect ratio, and I tuned it to actually have the appropriate line length to keep the orientation straight.

It still doesn’t find the sync pulse yet, but it will soon. Interestingly enough, the sound card is accurate to less than one sample in 11025, the difference between the nominal sample rate and the one that produces straight vertical lines is less than one half a sample per second. I find that pretty amazing.

Addendum: I mentioned yesterday that i was getting a much better signal from Australia than from Point Reyes. Here’s an example of images that I’m getting from Pt. Reyes.

Ugly.

Got home, and didn’t feel like standing outside in the rain and wait for a satellite pass. But I did feel like doing something radio related. So, while sitting on the couch during Big Brother, and the first 10 minutes of a recorded episode of Boston Legal, I hacked together a simple program that did some of the heavy lifting in decoding an HF-FAX recording that I did yesterday. This was recorded from the Australian VMC station in Charleville. It doesn’t do determine the sync rate, the aspect ratio, nor does it really work very hard to get the color ranges right, but it does give an image (and much better than the decoder that’s part of cocoaModem). Witness:

I’ll undoubtedly get it working even better, but it’s encouraging.

Addendum: It’s odd, but I’m getting MUCH better signals from Australia than I am from Pt. Reyes. It’s like I’m getting some kind of horrific multipath from the nearer site. Very odd. I’ll investigate further some other time. In the mean time, I got another one, pulled it into gimp for a little fine tuning, and here’s the result (there is an odd artifact that appeared in two images that I made, so something might be going slightly wrong, I’ll have to check it out).

That’s enough for tonight.

Ditch the diet soda if you’re trying to lose weight

In a study to be published today, American researchers found that rats fed yogurt sweetened with zero-calorie saccharin later consumed more calories and gained more weight and body fat than rats fed yogurt sweetened with sugar.

Yep, I know, this story has nothing to do with radio. I’m back working on my diet again. During Ratatouille, I managed to get busy enough that exercise and diet began to take a back seat to other concerns, and I gained about 25 of the 70 pounds I had lost back. Sigh. I’m back at Weight Watchers now, and am down about five pounds in the last three weeks. Slow and steady.

But this report doesn’t really surprise me very much: it’s not at all surprising that when you refuse to feed your body with calories when it wants it, your metabolism shows and you are more likely to eat inappropriately later. We should all watch our consumption of refined sugars and starches, but substituting sugar free and fat free snacks is probably not good either.

On Saturday afternoon, I was tuning around with my FT-817, and heard VP6DX calling CQ on 20m SSB. He was working split, transmitting on 14.190 and listening on 14.245 (from memory, have the split frequency wrong). It turns out that he’s part of a DXpedition: a trip by a radio amateur to go to a remote location and operate from their. It turns out that VP6DX is operating from Ducie Island, a small member of the Pitcairn islands in the south Pacific, with a total area of less than four square kilometers and no permanent inhabitants. Whacky! I wasn’t really setup for transmitting, so I didn’t bother trying to call him. Indeed, since the FT-817 only puts out five watts and my antenna is hardly optimal, I’m pretty sure it would be pointless, but I thought it was kind of neat to hear him.

VP6DX Ducie Island 2008 :: About Ducie Island