Rainy Mornings and Boring Bicuspids

Alas, another fleeting patch of free time has been bestowed upon me. Just like last semester, this semester (my second in a 4 year dental school) started off tough from day one. After Christmas break it was hard to walk into class at 8am and hit the ground running, but I managed to get the hang of it after a few days. I’ve heard medical school being described as “trying to drink from a fire hydrant”, but I think a more appropriate analogy would involve a treadmill set too fast. You have to work as hard as you can as soon as your feet touch the ground, and you might be able to keep up for now but you don’t know how much longer you can go before you tumble. I never really tumble, but I always feel like I’m about to. Overall, I can’t complain. I’ve managed to compartmentalize dental school into a chunk of my schedule (albeit a massive chunk), leaving time to spend with my family (wife) and when she’s at work, time to spend playing with electronics (which seems to be radio at this stage of my life).

Rather than bore the internet with descriptions of what I’ve been up to in dental school, I’ll focus on the interesting aspects of my most recent endeavors. A few weeks ago I took the final (third-level, extra class) amateur radio license exam. It’s a bunch of technical questions about radio circuitry, antenna theory, and other random stuff. You can see what I mean by taking an online practice test! I passed [whew!] and applied for a new call sign (extra class operators can have shorter call signs). The FCC gave me a VD. AJ4VD that is! Yes, my old call sign KJ4LDF has gone out the window as I am now AJ4VD! In morse code, that’s [.- .— ….- …- -..]. Speaking of code, I made my first contact in Morse code from my apartment! Let me set the scene for you…
Ten_Tec_Century_21
This is the radio I’m using. It’s a Ten-Tec Century 21 HF CW transceiver which puts out ~30W.
antennaBig
I’m using a super-cheap but surprisingly functional homebrew base-loaded vertical antenna! The main vertical element is quarter-inch copper pipe from Home Depot (a couple bucks) cut with 1” to spare from my 10ft ceiling. Therefore, it’s a less-than quarter-wave vertical element, requiring a tuning coil (variable inductor at the base)…
antennaBigger
Here you can start to see the tuning coils. Briefly, I scraped a deep gash in the copper pipe such that a big glob of solder would adhere to it, and stuck a wire (yellow, coated) into that solder so it’s a good connection to the pipe. I then started wrapping the wire around a few toilet paper rolls [it’s all I could find at the time!] adding tap points (regions of exposed wire) every other turn. This functioned somewhat, but didn’t allow for fine-tuning (pun intended). I therefore scrapped the bottom half of the cardboard cylinder/coil and constructed a slightly more elegant solution…
antennaCoil
That’s an Olvaltine container. Yeah, I know, “More chocolaty Olvaltine please!” I used a rotary tool to scrape some measured/templated gashes on each side to give the wire (picture frame hanging wire from Target, 50′ for $1.99) something to rest in. It turned out not to be enough, so I hot-glued the wire into the holes. This gives me a lot of exposed wire space to allow me to “tap” the coil wherever I want. By modifying where I clip onto the coil, I modify the length of wire in the coil that’s used, therefore modifying the inductance of the coil, allowing for some tuning capabilities. Although it has a narrow tuning range, using the current setup I’m able to get my SWR down to 1:1 on 40m (nice!).

I made a couple of contacts since I got the rig last night. First was K4KOR in central TN, who was calling CQ. I replied (slowly), and he came back to me (blazing fast Morse code). I was unable to copy ANYTHING he said (I’m not that good of an auditory decoder yet!) I’m sure he’s incredibly nice and it wasn’t intentional, but I had to give up the QSO. I know he copied my call, and I copied his, but I didn’t copy ANYTHING else he said. Does that count as my first contact? This morning I fired up the rig at 9:15 and heard W4HAY calling CQ from Northeast TN. I replied, stating that I’m new to CW so go slowly, and he was AMAZINGLY nice at sending me code at a snails pace. I was able to copy 90% of what he said, and will consider him my first solid contact! How cool is that?

And, as a closing note, Misia performing “Everything” (my favorite song) in Seoul, Korea:


     

CEJ, QRSS, and Life Recontemplation

Yes, I did it. I’m probably the first (and let’s hope the last) human to ever write CEJ (the abbreviation for the cemento-enamel junction, a dentistry term) immediately before the letters QRSS (extremely slow speed Morse code transmissions, a radio frequency term). Anyhow, thanks in part to the temporary cessation of the tortuously monotonous dental school I’m enrolled in, I have had some time to put into random obscure hobbies. For example, I’ve become somewhat obsessed with QRSS, an obscure sub-niche of amateur radio (ham radio).

I only have a couple of minutes to write, so I’ll be concise. In brief, QRSS uses extremely simple radio transmitters at extremely low power to send an extremely slow Morse code message over an extremely large distance to extremely sensitive receivers which are extremely dependent on computers to decode. While you might be able to send a voice message across the ocean with ~100 watts of power, there are guys sending messages with 100 milliwatts (one tenth of a watt! you can get more than that from a couple AA batteries!). The theory is that if you send the signals slow enough, and average the audio data (fast Fourier transformation) over a long enough time, weak signals below the noise threshold will stand out enough to be copied visually.
qrss_kj4ldf

Without going into more detail than that, this is the kind of stuff I’ve been copying the last couple days. The image is a slow time-averaged waterfall-type FFT display of 10.140mhz from a Mosley-pro 67 yagi mounted ~180 ft in the air connected to a Kenwood TS-940S transceiver sending data to a PC through a SignaLink USB sound card. Red ticks represent 10 seconds. Therefore the frame above is ~10 minutes of audio. The trace on the image is from two different transmitters. The upper trace is from VA3STL‘s QRSS quarter-watt transmitter from Canada described here and pictured below. The lower trace is from WA5DJJ‘s QRSS quarter-watt transmitter in New Hampshire, described and pictured here. Notice my call sign (KJ4LDF) at the bottom of the page!
qrss_transmitter

^^^ That’s the ACTUAL transmitter I’m hearing from Canada!!!

I don’t know why I’m drawn to QRSS. Perhaps it’s the fact that it’s a hobby which only a handful of people have ever participated in. It uses computers and software, but unlike SDRs (software-defined radios) they don’t require complicated equipment, and a QRSS transmitter or receiver can be built from a few bucks’ worth of parts.

HELPFUL FOR ANYONE WHO USES ARGO!!! 10_01_01_00009There’s a popular QRSS “grabber” software for Windows called Argo. It dumps out screenshots of itself every few minutes, but doesn’t assemble them together!!!!! It’s so annoying. I therefore took it upon myself to write a script to assemble several (or thousands) of Argo screen dumps together as a single image. It’s a script for ImageJ. To use it, first install MBF’s ImageJ. Open ImageJ, drag and drop a DIRECTORY of screenshots / captures into the program to open them as a stack, make a new macro, copy/paste the following code into it, and hit CTRL+R to run it, and poof! The output is a gorgeous panoramic shot like below.long

And here’s the script to automate the process…

makeRectangle(13, 94, 560, 320);
run("Crop");
rename("source");
frames = nSlices();
newImage("long", "RGB White", (frames-1)*560, 320, 1);
for (i=0; i<frames; i++) {
	selectWindow("source");
	setSlice(i+1);
	run("Select All");
	run("Cut");
	selectWindow("long");
	run("Paste");
	makeRectangle(i*560, 0, 560, 320);
}
//run("8-bit");
//run("Enhance Contrast", "saturated=0.5");
selectWindow("source");
close();

As far as life recontemplation goes, I’m discovering that it’s not the attainment of a goal that gives me pleasure; it’s the pursuit of the goal. Perhaps that’s why I peruse hobbies (goals?) which are notoriously difficult, and further challenge myself by doing things in weird, quirky ways. For example, I’d love to get into radio, BUT I HAVE NO MONEY!. Yeah, an all-band 100-watt HF/VHF/UHF rig would be nice, but I don’t have hundreds of dollars to fork over. Worse yet, in the technical sense, I do, I’m just trying to be responsible and saving it for emergencies / tuition and waiting until I’m a dentist (a.k.a. have a job) before I spend money on things that make me happy. Anyway, without complaining I built a non-elegant but surprisingly functional base-loaded vertical HF antenna for my apartment balcony (don’t worry neighbors, it’s taken inside after every use). It’s mainly for receive, but I don’t see any reason why it couldn’t be used for QRP transmitting! Here it is on my balcony…
ant_1

As you can see, it’s ghetto. Yes, that’s an antenna made from copper pipe, wire, and toilet paper rolls. I’ve wound the wire around the base and created various tap points so it serves as a variable inductor depending on where I gator-clip the radio. Not pictured are 33′ radials running inside my apartment serving as adequate grounding for 40m operation. The antenna feeds into a Pixie II direct conversion receiver / QRP transmitter which dumps its output to a laptop computer. Note that I did *NOT* use this setup to receive my beautiful QRSS signals. With that being said, I have copied PSK-31 transmissions from Canada with this setup. It works way better than a long / random wire antenna because it dramatically reduces noise. Here’s a closeup of the tap points on the inductor base…
ant_2

That’s it for today folks! Back to my crazy projects. Take care!

UPDATE: VA3STL mentioned me on his site! Woo hoo!