It isn’t hard to figure out the timing of traditional Morse code: A dit lasts one time period. A dash is three times as long. All elemtents (dots and dashes) within a character are separated by one period. Characters are separated by three periods. Words are separated by seven periods. Using this, the word “PARIS” takes 50 time periods, so the length of each period is 1200 / WPM milliseconds when WPM denotes the desired speed in words per minute.

But how does his timing change with the Farnsworth spacing? Well, inside a given character, the timing all remains the same. We’d like to extend intra and interword spacings to slow the overall code down to a different rate. We’d also like to preserve the 3/7 ratio between those two intervals. The math was eluding me, so I did what all people do when they don’t know the answer to a question: I looked it up on the internet. And of course, if you ask the right question, you get the right answer. Mine came in the form of an article by Jon Bloom, KE3Z that appeared in QEX entitled A Standard for Morse Timing Using the Farnsworth Technique which you can get from the ARRL archive here if you are a member.

But if you can’t, here are the formulas. Let’s say that you are specifying the Farnsworth in terms of a ratio s/c, where s is the overall (slower speed) and c is the character speed in WPM. You then compute

t_a = (60 c – 37.2 s) / (s * c)
t_c = 3 * t_a / 19
t_w = 7 * t_a / 19

where t_c and t_w are the times (in seconds) that you have between characters and words respectively.

I’ll get this hacked into mscript shortly, and post an example.

Addendum: I’ve got the code added into mscript. Here are two samples of six random five-letter groups, sent first at 20wpm, and secondly sent at 20wpm, but with character spacing increased to slow the overall rate to 10wpm.

An example of both conventional timing and Farnsworth timing.

This dipole is actually a premanufactured one from radiowavz.com. It’s just a basic 40m dipole with balun, fed by 50 ohm coax. In my case, its mounted quite low: Its about 20 feet off the ground at one end, but it is tied to a short tree up my hill. so the middle is maybe 10 feet above ground, and the far end maybe only 6 feet.

So, the open question is: will raising the far end of the antenna lower its resonant frequency? Or is the antenna just cut wrong for the CW portion of the band?

Bets anyone?

Addendum: This website does show that as the antenna gets lower, the feedpoint impedance drops significantly, and also shows that dependent on height, the resonant frequency of the antenna can vary by more than 100khz. This suggests (unsurprisingly) that I should try to mount this antenna higher to provide an easier match in the 40m band. It also suggests that measuring an antenna close to the ground isn’t a good idea.

ICQ Podcast – Home.

Yes, I’m unflinchingly telling you those numbers. Okay, I’m flinching a tiny bit. Many people gasp when they hear that number. Hey, I’m 6′4″ tall too, so it isn’t as bad as it could be. Still, I cringe a bit inside when I see that “3″ at the beginning of my weight, largely because I know that it probably means that my blood pressure and cholesterol levels could use some work too.

Anywhere, there’s the setup. Here’s the new experiment: I’ve acquired a wifi enabled scale from withings.com. I blame Leo Laporte, because he mentioned he got one, and I decided that I would give it a shot. One of the interesting things about this scale is that you can set it up to echo your weight to both their own site, to Google Health, or to (gasp!) Twitter.

So, I’ve created a new twitter login called marks_mass to serve as the output for this device. Each morning I’m going to hop on the scale and get a weight + BMI reading, which will get echoed onto my twitter account (right now it seems to just be sending my weight, I’ll see if I can change that, I’m still getting acquainted with the device). And, all of my followers will be able to see what I weigh.

Here’s where you come in: if you have a reaction, positive, negative, doesn’t really matter, go ahead and respond to marks_mass. Send encouragement. Send disappointment. Send advice. I’m opening this up to harness the power of my peers to help me change my own attitudes and behavior.

Welcome to my grand experiment.

Click here if you want to see marks_mass, and if you like, you can become a follower.

Addendum:
I should also give a brief mention to the device. It’s a really nice little gadget, much nicer than any other bathroom scale I’ve had before. It’s got a very sleek black finish and a bright display that I can read easily when you stop on it. If you step on it with bare feet, it will weigh you, and if you continue to stand, will give you a progress bar as it determines your BMI. Setup for the WiFi was similarly simple. You go to their website, download an installer for PC/Mac. You then do a one time configuration by plugging it into your PC, which pairs it to your wireless access point and gets it registered. You can then create a profile, and use it to start monitoring your weight. (All future configurations are done over the Internet.) I’m quite pleased with the device thusfar.

Addendum²: Oh, and there’s an iPhone app too.

It does actually uncover one of my pet peeves: in describing the action of the reflector element of the Yagi, Diane claims that the reflector “reflects”, but when she added a director, she claimed that the director “focuses”. But if you are a clever person who maybe doesn’t understand much about how antennas work, you might reasonably ask how that actually works. After all, the elements are identical in composition, and are essentially placed the same distance from the antenna. Why does the director direct, but the reflector reflect?

If you can actually answer this question, you’ve begun to understand how antennas really work.

I used to have some Morse code practice cassette tapes a while ago. It used the Koch method, and was progressive. They began with just two letters, say K and M that were sent using Koch spacing (the space between letters were sent as if they were 5wpm, but the letters themselves were sent at 13wpm.) The tapes themselves were thus the combination of regular speech (giving you instructions) and Morse code. But I can’t find the tapes anymore, and even if I did have the tapes, I don’t have a cassette player, so they wouldn’t be of any immediate use. I went to HRO to see if they had any such thing on CD so that I could listen to them in my car, but ironically, the bottom seems to have fallen out of the Morse Code CD market, and they didn’t have any in stock.

So, I thought to myself, what would it take to make my own?

I’ve written programs to generate Morse code before. And most of the computers I use have some kind of speech synthesis capability (either the “say” command on Mac OS, or the festival speech synthesizer on Linux) so generating some reasonable if not exactly pleasing speech wouldn’t be that hard.

So, I tossed together a simple scripting language to wire the two together. It takes a simple script which consists of text which it translates directly into Morse code. The exception is any text which appears in double quotes. It gathers that text up, and passes it to the system speech synthesizer, and generates a sound file, which it then reopens, resamples to the same output rate as the rest of the morse code, and then returns to Morse mode. This isn’t all that hard because of the excellent libsndfile and libsamplerate libraries. There is some work left to be done, but the basics work. Here is the contents of a simple test script that I wrote:


"This is a test of the emergency broadcast system."
If this had been an actual emergency,
you would not have been using Morse code.


And here is the resulting .mp3 file, synthesized on my Macbook:

Morse synthesized by my “mscript” program (MP3)

The basics all work, but there are some additions to be made, to insert arbitrary wav files perhaps, to adjust timing, to implement Koch spacing and flexibility in changing the speed of Morse code inside a single document, and just other bits of cleanliness. Oh, and the Morse doesn’t have any shaping at all, so the transitions are a bit clicky. I can fix that pretty easily. Still, not bad for a couple of hours of tinkering with C, yacc, and lex.

Internet Archive: Free Download: The telescope.

Oscar.com – Nominations – Nominated Films.

Congratulations to my fellow Pixarians.

Addendum: I hadn’t heard that there would be ten best picture nominees this year. Here’s the press release that announced it.

MR. B. N. BURGLUND, whose description of the wireless station at the University of Michigan, appeared in our March number, writes us an interesting letter on the part played by wireless amateurs during the recent floods in the Middle West in March. He has much to say in praise of those who did good work and rendered efficient service; and he also condemns, in no uncertain terms, the meddler who, we are sorry to admit, appears to be always on the job and gets in his fine work at such times. One of these individuals, possessed of a powerful transmitter, and ignorant of the code except to the extent of being able to recognize a few well-known calls when he heard them, persisted in calling the station at the University of Michigan while the operator there was trying to handle messages from the flooded districts. He was told, repeatedly, to keep out, but being ignorant of what was said to him, and thinking his calls were simply being recognized, kept on calling. And he kept it up for over six hours. The wireless law provides a heavy penalty for offenses of this sort, but he did not sign an understandable call and will probably never be caught.

via The Wireless Amateur in Times of Disaster (1913).

The book of wireless telegraph and telephone : being a clear description of wireless telgraph and telephone sets and how to make and operate them, together with a simple explanation of how wireless works.

I was watching America’s Test Kitchen, where they were making homemade “shake n’ bake” style porkchops and applesauce. I didn’t really feel like having porkchops, but because I’ve been eating poorly lately (too many restaurants because of visiting son and his wife, and my own visits to my brother) I had a bit of a sweet tooth, and the idea of making some homemade applesauce sounded really good, and much better for me than the ice cream which I’ve been indulging far too often in lately.

If you buy applesauce in a can or jar, far too often it suffers from a number of problems. It can be made from apples which just aren’t very good. It’s often far too sweet, with lots of high fructose corn syrup. It can have preservatives or other additives. Often it includes overpowering spice elements like cinnamon. Yuck.

America’s Test Kitchen suggested a very simple recipe. Take 4 pounds of apples. Wash them, core them, and dice them into coarse chunks (skin on). Put them in a pot. Add 1/2 a cup of sugar, a pinch of salt, and a little water. Cook for around 15 minutes, until the apples are soft, and then put them through a food mill to remove the skins and even the texture.

They suggested a number of different apples that could be used. For my experiment, I used eight of the Pink Lady variety. They are related to the Golden Delicious, but have a nice rosy color to them that’s pretty. Eight of them was about 3.5 pounds uncored. I chopped them fairly coarsely, added a splash of water, a pinch of salt, and just a little sugar (no, didn’t measure, but probably less than 1/2 a cup, maybe just two table spoons). I set this covered on medium heat.

After a few minutes, you could smell a cider-like smell, and the apples began to boil and liberate a lot of water. I thought that maybe I had too much water, but after a few more minutes, the apples began to break down and lots of the liquid was reabsorbed. After about 15 or 20 minutes, the apples were soft and smelled delicious.

I don’t have a proper food mill, so I just took a potato masher and crushed ‘em. Yep, skins still on, but as I mashed them, they lent their rosy color to the mash, and I actually liked the textural element. I added a very small amount of cinnamon, stirred it in, and then let it cool for a couple of minutes.

It was delicious. What’s really great is how the fresh complex flavor of the apples really come out. They are sweet, and tart, and clean tasting. Next time I make pork chops, I’ll have to make some of this applesauce. I think it would also be good with a scoop of good vanilla ice cream, or maybe with a cobbler like topping of oatmeal and brown sugar and maybe some cold cream.

We don’t appreciate these classic foods very often, at least in the way that they used to be made. Thanks to America’s Test Kitchen for motivating this delicious culinary experiment.

Put it in your daily list of reading. And Jack, if you are reading this, best wishes to your endeavors, ham radio related and otherwise.

ea3ghs – MOSQUITO Minimalist Transceiver.

M1KTA’s QRP ham radio blog: PTO VFO.

I’ve had this in the back of my head as an interesting project, so seeing notes on someone building one is inspiring.

About half the book is dedicated to the Box Kite Yagi, which are basically a collection of Yagi antennas which are carefully designed to optimize gain relative to previous state of the art Yagi antennas. For instance, a six element 2m Boxkite has a boom length of approximately 85 inches, and has a gain of approximately 14.6dBi. If I try to make a 144Mhz Yagi using DL6WU’s classic long Yagi design and with similar gain, I end up with a boom 427 inches long (almost five times as long). I frankly am not experienced enough at antenna design to understand the tradeoffs involved here, or whether there (say) the box kite is more sensitive to fabrication errors, but reducing the overall boom length to such a dramatic degree is very interesting. He also has designs for interesting dual band designs, such as a small 6m/2m yagi that has around a 7 foot boom. Very nice, and thought provoking. I’m wondering whether an antenna like this aimed toward the moon rise/set positions would enable me to receive JT65 EME transmissions. Very neat.

I’m also quite interested in the “C-pole” antenna design. It’s a short vertical antenna which has very good low angle takeoff, and requires no radial system. There was an article about them in QST a while back, but a lot more details in the book.

Some of the more thought provoking antenna design notes I’ve seen in a while. I am glad I picked it up.

Vicacopter.

The vehicle will be a 1200g helium-filled latex balloon. The expected burst altitude will be 90,000 feet or higher. The flight is anticipated to last about 2.5 hours from launch to touchdown.
Payload: In addition to ANSR flight computer/cross-band repeater and beacon packages, the balloon train will carry student-built packages containing a variety of scientific apparatus as well as digital cameras to photo-document the flight.

The posting includes links to the APRS tracking pages where you could monitor the flight over the Internet.

Arizona Near Space Research | Promoting science and education by exploring frontiers in amateur radio and high altitude balloons..

Excerpt

Addendum: Picked up CX2ABP in Uraguay:

Addendum: Overnight, I picked up LA3JJ and VK4YEH among others:

Addendum: Overnight, it appears that my monitoring PC decided to download some security updates and reboot. Hence, logging ceased about 3:15AM local time. I just fired it back up, and got 7L4IOU in Japan and VK6POP in Australia.

A few months ago, I found a truly nifty font that enhances my sense of nostalgia. It’s a very cool True Type font, which is carefully designed to match the old VT220 font, complete with the “scanline” appearance that I remember. It’s actually a pretty nice legible font as well. Perhaps you’ll enjoy it.

Hacking with Style: TrueType VT220 Font.

Today, I unsubscribed not just because it was boring, but because it is whining. Not just whining, but members seem to be piling on the idea that if someone doesn’t operate in a particular way that you approve, that they are entitled to maliciously jam your transmissions.

That’s illegal. It’s also first-order dyed-in-the-wool jackassery.

Goodbye QRP-L. It was nice knowing you.

On second thought, maybe it wasn’t that nice.

But amidst the general complaints, there are a few points which they make which we should all take to heart. First of all, in the United States we are not allowed to operate automatic beacon transmitters below 10m. This means that you have to be in control of the station, and operate it in a manner consistent with Part 97 regulations. I’m not sure what that really means in the context of this mode, but I suspect that it means that running your beacon all night while you sleep isn’t actually legal, as fun (or useful, I would argue) as it might be to see those spots from New Zealand that occur at 4:30AM local time when you wake up and have your coffee. I believe that all hams should endeavor to operate their stations in accordance to regulations, so I think that we as WSPR operators should be at the control point of our stations when transmitting WSPR. I also think that this point of legality isn’t adequately emphasized in existing documentation, so new users of the mode may be unaware of this issue, so it would be great if we had a more prominent notice on WSJT’s site, and on wsprnet.org.

Beyond simple legality though, I’ve seen that the QRP-ers have some basis for being irritated beyond the mere legality of this operation. In the last 24 hours, I’ve logged one particular station who has operated at 100w output power, and for quite a while, was transmitting about 50% of all slots, including many back to back slots. This resulted in spots with a SNR of +5 over distances of 12000km. This isn’t a WSPR, it’s a rock concert. I think its good to keep WSPR at QRP levels or ideally QRPP levels. And let’s keep our transmit percentage down to 20% or less. As WSPR has become more popular (and it has become much more so even in the last few months, with dozens of stations on 40m and 30m) we’ll need to reduce the time we spend transmitting to mitigate collisions.

And let’s be especially careful around 40m, okay? 7.040Mhz isn’t the best choice of frequency, frankly. Lots of old time rock bound QRPers still claim it as their own, and while nobody owns a frequency, we should be courteous to all hams.

It’s late, and been a full day, so I can’t really say that I understand this position. But Milhouse doesn’t get tired: when I load the endgame database, it immediately proclaim that the position is a draw. What’s more is that it identifies two different lines: their website suggests 23-26 as a drawing move, but 19-15 is also a draw.

Without the endgame database, White thinks it is down a man, but with a 25 ply search can’t find the draw. In addition to the two moves listed above, it thinks that 23-18 is also almost as viable. But 23-18 is a dead loss, presumably because it allows Red to king both of its checkers. Even with the database though, Milhouse can’t seem to find the win for Red in a 31 ply deep search. This seems like a good test case for future improvements to playing with the database.