ISS on 20m

No not that ISS! This is station II5ISS which I worked on 20m PSK31 whilst testing some tweaks to KComm.

If you're interested, you can win an award by working II5ISS on three or more bands before the end of 2013.

Who says it can't be done?

I always like reading about what can be achieved using a stealth antenna system, so I always enjoy reading the blog of John, N8ZYA.

From a town house in Charleston, West Virginia using 3 watts of CW to an indoor random wire, John has made 1,830 contacts including 361 DX stations in 73 different countries. Simply amazing!

I hope you don't mind me pinching your picture, John!

Classic WSPR vs WSPR-X

Are you a fan of WSPR mode? Have you tried K1JT's new program WSPR-X yet?

Comparing classic WSPR to WSPR-X

I decided to switch to the newer program as the older 'classic' version won't work with VSPE virtual serial ports. But I had a sneaky feeling that WSPR-X was not decoding some of the traces it should. So I decided to run both programs in parallel, using the same sound card, the same radio, the same data source. Sure enough, WSPR-X is missing about 1 decode in 10 compared to WSPR 2.11. There is no apparent common factor between the signals it missed. They are not at the extremes of the frequency range, close to the limit of timing error nor especially faint.

Look at the screenshot above and look at the decodes for 1540. Classic WSPR has decoded two signals for this interval whilst WSPR-X has decoded only one. The signal from W3CSW was missed. Later signals from the same station were decoded. That is just one example. I only needed to wait a few minutes to find another.

I set the older WSPR to save .wav files and when these were processed by WSPR-X using its File Open option the result was the same as when the signals were received off-air. The same transmission was missed in each case.

WSPR-X seems a bit faster to run the decodes than WSPR. It prints them up on the screen before classic WSPR does. There are sometimes slight differences in the dB and DT figures, but not enough to worry about. Has anyone else noticed this?

Ghosts on JT9-1

I spent a couple of hours working JT9-1 on 20m this afternoon. I only messed up once when I forgot where I was in the sequence. I could do with the software showing the outgoing message in the log as well.

I think word of the new mode is spreading slowly as even on a Sunday there were not many new stations to work. N1ISA(FN41), WB2LMV(FN21) and KC2RDC(FN14) were the only DX worked.

One Italian station was a record +24dB during one call. I reduced power to 1 watt but I still received a +00 report from him. I don't know how much power he was using but it is a bit unfair to accuse a station of using too much power when even QRP signals are strong. WSJT-X seems to hold up better than JT65-HF in the presence of a very strong signal, as even in the presence of signals well above 0dB I was still getting decodes.

One thing I have noticed when receiving strong signals is that I get duplicate 'ghost' decodes at 100Hz intervals on either side of the main trace. Look at the four decodes of IK3SCB at 1701. There must be some 100Hz modulation of the signal, but I don't know if the cause is at my end or his.

WSJT-X update

A couple of days ago I had an email from Joe, K1JT, author of the WSPR and WSJT software. He had read my post about my first JT9-1 QSO in which I said that I missed the JT65-HF user interface. Joe pointed out that WSJT-X is in a very early stage of program development, and user input will surely help to define its future evolution. He asked what features of the JT65-HF GUI I found desirable.

I replied with what I thought were the key points that made JT65-HF easier to use. The result is a new version of WSJT-X which I have just tried. One change is that the horizontal 'panadapter' display scale now matches the waterfall when the user has set FFT Bins/Pixel greater than 1.

However, the real big change is that double-clicking on a decode line now generates a set of messages addressed to the second callsign on the line, regardless of where you double-click. It also sets the Tx and Rx frequencies to that of the decoded transmission and selects the first message in the sequence. This is a big time and error-saver in the few seconds you have between receiving a call and having to reply. You still have to set Auto to ON to enable the transmitter and select the next message in the sequence after the first has been received. Perhaps it's a matter of personal preference but I don't think it is a bad thing for the user to take control of this rather than have the program try to work out the appropriate reply. In other words, double-click on a decode when it is a CQ call or a reply to your CQ. Use the Tx n buttons to select the next message in the sequence as you progress through the QSO.

Try this latest version of WSJT-X. I think you'll find it a big improvement. Now all we need is for Laurie VK3AMA to come up with a version of JT-Alert that adds logging and 'worked before' detection and there will be no reason not to switch to this much narrower JT mode.