Monthly Archives: August 2008

QRSS experiment…

Well, last night, conditions on 40 and 30 were frankly pretty terrible. I tried to get a couple of VE3s to pay attention to me on 40m PSK31, but it was not gonna happen. I was lamenting this on the IRC freenode.net #hamradio channel, and NM5DV decided to give PSK-31 a try. He was running higher power than I, so I didn’t have too much trouble picking him out, but I was marginal (but good enough to rack up the QSO). After that, we dropped back to the good ole Internet, and mused about what we could do.

I had been goofing around with trying to receive QRSS (very slow Morse signals), and for fun had jury rigged a setup to actually send them (in the most stupid way imagineable). Here’s how I send it with my FT-817:

I generate a sound file (using a program I wrote) that contains morse at the very slow speed I want, and say a sidetone of 1000Hz. QRSS3 specifies a 3 second dit time, which makes the file that contains my callsign three minutes long. We started out with that, but I made a version that was QRSS1 (1 second dits) which makes my transmit periods that much shorter, a mere one minute to get my call out. Here’s what it sounds like:

KF6KYI in QRSS1

Now, the sleezy part: to transmit it, I just loaded it up into iTunes on my macbook, and then let it loop endlessly. I set my FT-817 to digital mode, tuned 1Khz below where I want the signal to appear, and then use cocoaPTT to key on the transmitter. Voila! Beacon!

And here’s what NM5DV captured using glfer from grid DM75. It’s not really that impressive: I was running 5 watts for this transmission, we diddled around with trying to use 500mw. He could still see that, but it was hard to pick out the callsign. As it is, this one shows significant fading during the last dash of the second K. Still, conditions really were terrible, and the distance was about 1000 miles, so I thought it wasn’t a complete failure. I also think that if we really knew what we were doing, we could probably tune glfer to do something a little better.

Anywho… it was kind of amusing.

This morning? Two letter beacons…

Yesterday, I was playing with WebSDR, an awesome software defined radio that you can access from the web, and I noticed that there was a Morse signal on the 40m band that just repeated “D” endlessly, and right next door, another that repeated “C” endlessly. A bit of digging revealed that these were “letter beacons”, transmitting from the ~~Soviet Union~~ Russia. (Man, I’m dating myself by accidently calling it the Soviet Union.) Neat, think I. They all appear clustered around 7.039 or so on the 40m band, so I bet that lots of radio amateurs have heard them all the time. Anyway, here is the Wikipedia link.

Letter beacon – Wikipedia, the free encyclopedia

But this morning, I was having a little breakfast and turned on the radio. For kicks, I dialed down to that portion of the band, and, oddly enough, could hear “dah dit dah” and “dah dah” repeating. Wow, those are beacons “K” and “M”. Here’s a picture of what the signals look like through my spectrogram code:

Here is a link to the MP3 recording I made. As I am editing this post, I am continuing to listen to the live radio. I can still hear M pretty clearly, but K has been fading in and out, and now I can’t hear it very often.

I’ll probably work out the distances to these transmitters later. According to my calculations, the K signal is at about 7.039315Mhz, and the M signal, about 7.039415Mhz, 100hz higher. The Wikipedia doesn’t list a 40m frequency for K, but it lists 7.0394 as being a frequency for M, so I’m pretty close.

Addendum: According to Wikipedia, the K beacon is in Petropavlovsk-Kamchatsky, which works out to grid QO59jn, and M is in Magadan, in grid QO93ha. Running my grid program, I get bearings of 313.4 degrees and 322.5 degrees, respectively, at distances of 3755 and 3903 miles.

Addendum²: It’s now the next morning. I can hear K and M again around 7.039, so I guess that isn’t that difficult. I tuned upo around 10.8725, and found M broadcasting there, a bit more difficult to find, but it’s pretty clear. Here’s the spectrogram:

$\"M\" arount 10.8725$

Addendum³: It’s a couple of mornings later, and I’m still hearing them. My guess is that I’m getting so-called “gray line” propagation from northern Russia, but I should really plot that out on the map. This morning, I decided to try to make the beacons more obvious by plotting their intensity using a logarithmic scale. Maybe it’s better, maybe it’s not.

Receiving QRSS

Conditions have been really bad on 30m. I haven’t had any luck at recording any beacons at all in the MEPT subband, so I was bored. I went to this page and found a recording of some QRSS signals:

Receiving QRSS

My software renders this out as this, clearly showing the two FSK shifted morse signals.

IBP software for Linux/Unix

Well, the bands were really dead this evening, so I decided to try to see if I could find some software that might be useful. I sometimes monitor various beacons, and the NCDXF beacons are the most famous. There is luckily this neat little program:

IBP software for Linux/Unix

available for Linux that can help you figure out what beacon you are hearing. It’s even got a nice little graphical display of the earth, showing what portions are lit and which are dark, and what the bearing is to the transmitting beacon.