Sunday, January 30, 2011

Weekend Weak Signal

I spent a large part of the weekend focusing on JT65A yet again. This mode is extremely fascinating to me due to the weak signal decode ability that it has.  I also did a bit of PSK31 looking for that last state I need for LOTW WAS, Maine. Came up short yet again with Maine but I know someone willing to send Maine my way on PSK31. He has offered, I just need to set up a sked. I was hoping to get it by chance, but I think with another high speed solar wind due to strike again in the next week, I had just better take advantage of the offer.

The map above from PSK Reporter shows some of areas I had propagation to over the last 12 hours. You will see some European stations on this map from earlier this morning. I had become frustrated with PSK31 as a digital mode to contact European stations as the software and mode does not do well with polar flutter. JT65A is much better with this but even it has limits with polar flutter. I found this to be the case this morning as I attempted to decode a few stations on the other side of the North Pole.

You can see I had several moderately strong stations in the waterfall but I often times would go one to two minutes between a decode (screen shot to the right). PSK31 would not have decoded a trace but at least JT65A does better with this condition. Again, with the echo and flutter, it does have some limitations but at least I can work stations under this condition. I messed around with the audio input settings (a bit high as seen here) but even the signals show a much wider trace than normal. I believe this is a visual indicator of the flutter and echo I was hearing. Either way, this software / mode does extremely well and I have tested it on my strong and weak bands. It has allowed me to work parts of the lower 48 or other countries I did not think I had the ability to work due to my station limitations. It's awesome to be able to have a valid contact with a station that is as weak as -24dB! Not possible you say? Just give it a try and you will see..

Here is a perfect example of the ability of JT65A (using JT65-HF software). I do not have a 160 meter antenna but my Hustler ground mounted 5BTV will actually tune this band. While typing this blog entry, you will see I decoded W3ZUP in FM19. He resides in Maryland, which is over 3,200 miles away from my QTH. The software decoded him with a very weak -25dB signal using my vertical! Now, how impressive is that? Not only did it decode him once, but it decoded him a second time at that signal strength!

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I guess since I have written about this mode a few times, you can sense my excitement about it. But I'm sure others also feel as I do. This gives us small stations a way to work states and countries we never expected to work. Heck, I have worked farther on 80 meters than I have ever worked before. I did not think that WAS (Worked All States) was a possibility on 80 meters for me but with this mode, there is hope! The JT65A crowd is growing daily so the more stations that are on, the better my chances to accomplish my award goals. Plus, there is something about calling CQ and seeing someone coming back to your call and the anticipation as you wait to see who it is, approximately 50 seconds later.


  1. You and I are obviously both on the same wavelength, Phil.

    BTW the smearing of the tones you see is a result of Doppler from the turbulent ionosphere.

  2. Thanks, Larry! You should see my log, lots of JT65 QSO's. Like you, I am sure having fun with this mode. Nice to be able to finally work back into the NE on 80 meters.

  3. Hi Phil, I just returned to JT65A on HF and have been heard in ZL (18000km+) with only my 5W and my 80m loop. That indeed is a lot of excitement. Although I do not have the flutter you have I can imagine your exitement. I think next time I'll try with my Icom 706 with a bit more power to see if you can receive me. 73, Bas

  4. Bas, that's awesome! Yep, just need the right propagation and a bit of luck on the other end of the line. New radios have great receivers in them and married to great software like this, it makes the impossible, possible. Addicting for sure.

  5. RR on using a 5BTV and 100 watts on 80 meters, as I am now at 45 states including both Alaska and Hawaii to work. Did hear KL7IWC during the BARTG RTTY test, as I belive there is still hope.

    Perhaps JT65 will be in the stars for me afterall.

    73 de KJ8O

  6. KJ8O congrats on the 45 and good luck that the last 5!! Yea, the 5BTV allows me to listen to 160 and it actually tunes but by the time my 100 watt signal hits the antenna, it's probably more like 25. My vertical will work much better once I get it relocated and put a bunch of radials under it. I'm very happy with it fo sure. JT65 has really helped me get states I did not think I could get on 80. I of course have to be there at the right time when the wave of propagation is headed east but so far, so good! Thanks for reading and commenting!!! 73!