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Many people have blogged about their activities over the weekend during the ARRL DX CW contest. I had planned to spend some time making some Stateside contacts, to see how many different states I could work and perhaps make enough contacts to be worth submitting an entry, even though I had no intention to win anything. Alas it was not to be. After just over an hour on Saturday afternoon, during which I had made 17 contacts on 15m, Olga learned that her sister in Ukraine was in intensive care in hospital. It would have been inappropriate to carry on making contacts on the radio, even if I had still felt like it after receiving that news. So that was the end of my participation in the ARRL contest.

Olga felt she would have to go urgently to Ukraine to see her sister, which made me depressed and anxious. Kharkov isn’t the easiest place to get to from here, even without snow both here and there making the journey more difficult. However on Sunday Olga received some better news about her sister, including the advice that there was little she could do if she went now and it would be better to wait until she was out of hospital before visiting. I’m still depressed at the thought of being without my wife and soulmate for a bit, but at least I will have more time to get used to the idea before it happens.

My interest in the contest didn’t recover after this, but I did read about a couple of new pieces of digital radio software which I tried out and wrote about yesterday. Both of these programs are very interesting, and I think I shall have more to say about them in the near future.

Another new digimode has made its presence on the airwaves. Called ROS, it uses spread spectrum techniques in a bandwidth 2.2kHz wide and offers a choice of two symbol rates, 16 baud and 1 baud. The latter will be of great interest to QRP operators as it is claimed to allow communication at signal levels of 35db below noise, which is better even than WSPR. ROS is an interactive mode, so you can type what you want and have a real QSO, unlike WSPR and the other JT modes that can only send a limited number of fixed messages. What’s more it isn’t an all-or-nothing mode like the JT modes, so you can receive a message that’s part garbage and use your own intelligence to correct the errors if possible.

An interesting feature of ROS is that the software will automatically send an emailed reception report to any transmitting station that includes his email address in his transmission. Quite how it achieves this I don’t know, since I don’t have an email client set up on my shack computer (I do all my email through Gmail.) So I was quite surprised after receiving my first ROS signal from G3ZJO running 1 watt on 40m to see him send “HI” to me on his next over (as you can see in the screengrab.)

This is yet another program that only recognizes the “default” sound card so I am once again receiving using the HB-1A transceiver and am unable to transmit using the mode.

The weak signal capabilities will no doubt make this mode of interest to the QRP fraternity as well as VHF operators working EME and troposcatter. I think the ability to receive an emailed reception report is also rather cool, and a bit more personal than seeing your signal spotted on a website.

However I do wonder what will happen once the massed hordes start using it on HF and begin cranking the power up to try to work further afield. There isn’t enough space on the HF digital mode bands for many simultaneous contacts to take place using a 2.2kHz wide mode.

I’m now listening on 14.101.0 MHz USB so if you try this new program and put your email address in your message you might get a report from me.

Chris, G4HYG, has just released a new Windows program called APRS Messenger which supports APRS messaging using the PSK63 mode. Various experiments made in the past suggest that this could give better reliability at low power levels than 300 baud packet which is normally used on HF. APRS Messenger also functions as an Internet gateway so any error-free packets received over HF are sent to the APRS-IS network.

An unfortunate limitation of the program at the moment is that it will only talk to the “default sound card” which on most Windows computers is the one used to play system noises, listen to Internet audio and video and so on. So I am unable to use it with my K3 at the moment. For test purposes I have connected my HB-1A QRP transceiver to my 30m antenna and fed the headphone output into the mic socket on the front of my PC.

I have decoded a few packets already, though many seem to contain some corruption. I am wondering why the little-used QPSK63 mode was not used for this application? As I understand it (and I could be wrong) QPSK63 takes up the same amount of bandwidth but incorporates some forward error correction that improves the likelihood of good copy compared with plain PSK63.

Chris has apparently agreed to talk with Lynn, KD4ERJ, about the possibility of making APRS Messenger work with APRSIS32. The possibility of using Lynn’s full-featured APRS client to send and receive APRS over HF using PSK is quite exciting.

By the way, if you are wondering why the screenshot shows a Mac program the reason is that I’m using an OS X theme under Windows XP!