April 9th is Tom Lehrer’s birthday.

I was having some difficulty spotting my beacon: both on WA0UWH’s grabber, and via WSPR spots. I figured that maybe my jury rigged antenna had fallen down, or I had some kind of similar hardware failure. Oddly though, my receiver seemed to be going strong.

I went over to my setup, and found that the power meter on my FT-817 was indicating basically no power going out. A few more minutes of checking cables and the like found out that my laptop had somehow muted its audio output, and therefore, wasn’t sending any signal out. I groaned, cranked it back up, and then verified it was putting out a signal, and went to bed.

In the morning, no WSPR spots remotely. None.

I was puzzled, until I thought to check the time on my laptop. Oddly, it was about 23 seconds off. WSPR is synchronized so that you transmit on even number minute intervals, and if you are more than a few seconds off, it won’t find you. The odd thing? I run the Network Time Protocol on my macbook: it should keep perfect time! I killed off the ntpd daemon, and it restarted, and was then resynchronized. I’m back to normal operation.

I’ve gotten a couple of additional sporadic spots from DX locations, so I thought I’d update my WSPR map again. This shows my reception from the Russian station RA6AS, Canadian VE1VDM (of Big Ears fame, and my most distant North American spot) as well as the LITCHFIELD station in Northern Australia. I’m still at 37 states. All spots with a path length of greater than 3000 miles are marked with a line showing the great circle path.

I was dusting off some of my old code for computing pi to many decimal places, and was reminded that I’d never written similar code for computing a more basic value: the square root of two.

The usual way to do this would be to use Newton’s iteration to solve x² – 2 = 0. If you apply this, you get the following
iteration formula:

         x
          n    1
x      = -- + --
 n + 1    2   x
               n

There’s a problem with this, you have to implement reciprocals (or long division) to let the Newton’s iteration work. If instead you try to solve 1/x^2 – 1/2 = 0, you get an easier iteration that also works:

                 3
         3 x    x
            n    n
x      = ---- - --
 n + 1     2     4

Here are some digits. It appears to work.

1.
4142135623 7309504880 1688724209 6980785696 7187537694
8073176679 7379907324 7846210703 8850387534 3276415727
3501384623 0912297024 9248360558 5073721264 4121497099
9358314132 2266592750 5592755799 9505011527 8206057147
0109559971 6059702745 3459686201 4728517418 6408891986
0955232923 0484308714 3214508397 6260362799 5251407989
6872533965 4633180882 9640620615 2583523950 5474575028
7759961729 8355752203 3753185701 1354374603 4084988471
6038689997 0699004815 0305440277 9031645424 7823068492
9369186215 8057846311 1596668713 0130156185 6898723723

Regardez!

For all my close friends who I’ve chatted with about today’s adventure: I’m home, and doing fine. But seriously, ouch.

I’m glad I didn’t try my hand at my second Softrock today. Instead, I decided to wire up all the programmable message buttons on my K1EL keyer (I had mounted them, but didn’t bother connecting them the last time I hooked them up). Man, my hands were jittery, I guess those two Diet Cokes really got too me. Still, finished it all, buttoned it up, and now I’ve got the keyer completely done. When my oscillator project gets completed, I’ll be able to go immediately to beaconing.

Oh, and I got my cheesecake baked for tomorrow’s brunch.

Sadly, last night I was working late, and was tired, and managed to delete a chunk of my grabber recording source code. The bad news is that I didn’t have it backed up, so I have to rewrite it. The good news is that hey, I get to rewrite it!

Seriously, it’s only a few hndred lines of code, and I pretty much remember exactly how it works, but it was reasonably subtle, and might take a bit of tinkering to restore. I’ll try to get it going Saturday.

Well, after failing on 20m earlier in the day, I waited a bit, until I saw that Felix, DP1POL had shifted from 20m to 40m. I then flipped my beacon/grabber over to 40m, and gave it a try at the 5w power level. And…

If you look carefully, you’ll see an unusual grid square. DP1POL is operating from the German Neumayer III Station on the Ekstroem Shelf Ice, Atka Bay, in Antartica. Felix will be working their for quite some time, so I will undoutably have multiple opportunities to get him on multiple bands.

Another reason that this contact is significant is that it’s actually my furthest DX, further even than VK6DI. I decided to remake my WSPR spot map:

While I won’t get quite as many spots with 10db less power, I think it’s more sporting. I’ve been seeing quite a bit of IMD on WA0UWH’s grabber, and stations VE7TIL have been receiving me with very large signal to noise ratios. I’ll let this go at the 250mw level for a day or two, and see how we do.

Addendum: Still getting into Seattle well. Check out the grab:

This is just a strange little story. I’ve wanted to add some time markers to the spectrum display on my grabber at http://qrss.info, but really didn’t want to link in any kind of fancy graphics code. Really, if I had the data for a simple 8×8 pixel bitmap font, I could plot the characters myself (after all, that’s pretty much how we had to do it back in the old days). So, I typed “8×8 bitmap font” in the Google search bar, found that a gentlemen named John Hall had made just such a thing, and said that it was free for any use. Very good, say I. I downloaded the PNG file that had all the characters, massaged it in a couple of ways, and three minutes later, I had a font definition file that I could use in my revamped version of my beacon app.

Later, I thought that it would be nice if I acknowledged the largess of my font-benefactor, only to find something odd: John “Overcode” Hall had passed away back in 2005 after a battle with melanoma. Here’s one of the announcements. Oddly enough, the website that I got the font file from earlier seems to be down. Very strange.

In any case, thanks John. I hope that after my time has come and gone, maybe some of this will live on, and inspire others. Or, at least help them hack together a program.

Addendum: Here’s the link that Google sent me to.

I think I’ll need to borrow an oscilloscope and see what’s going on. Frankly, I think I just made too many mistakes during assembly. Since I know at least four I made and corrected, I suspect another four luck under the cover. The primary oscillator seems to be running, but I am no longer certain the divider is running (it did when I previously tested it, but who knows…)

I’ll work on it some more again soon.

Okay, this one requires a bit of imagination, but it looks like my sequential, multi-tone Hellscrieber ID is at least weakly making it to VK6DI. I’ve marked it with the question mark. Below is where I believe my K6HX-CM87 should be, and above, just under the legend is my simultaneous WSPR message.

This morning I was surprised by two WSPR spots from a callsign reported as BY3AKL1X, located in grid OM89ua. If you look it up on the map, you’ll find it’s Tanggu Park, near Tianjin China. I was confused, but then realized that this was the call of KL1X, who (as pointed out to me by KC0KNM) lists that he is operating receive only from Tanggu Park since the beginning of this year (as listed on his QRZ page). Neat!