My second DV QSO
Just as I was finishing writing my previous post I heard someone else calling on the 20m DV frequency. It was Elie, OD5KU. Yesterday I had heard him working a French and then a Dutch station but signals were weak and not good copy at all.
I replied to Elie but he couldn’t make out my call. I tried several times and was about to give up when he called again with solid copy. Perhaps he had turned his beam my way. I tried calling one more time. This time he heard my reply and we had a good QSO with several periods of solid copy punctuated by occasional break-ups. These occurred when QSB took the digital signal down to near-invisibility in the FreeDV waterfall. I doubt that good SSB copy would have been possible at those times either.
I managed to make a recording of the end of this QSO so you can get an idea of the audio quality. It was recorded off-air using my Olympus digital voice recorder, then played back using the mic input of the USB sound dongle to make an MP3 file. Given the way it was created I think the clip is quite a good example of the FreeDV audio quality. As you’d expect from a digital signal either it’s all there or you just get gobbledygook. It doesn’t degrade gracefully.
Is this the future of ham radio? Have a listen and let me know what you think.
Thank you Julian
Great audio file
Very interesting Julian…great idea, recording it. Sounds somewhat rougher than DSTAR but it’s very good to know you can do communications quality QSO’s with considerably less bandwidth. The “R2D2” was a direct relative of that on DSTAR…they
say that digital voice is either in or out….but at the edges contain some interesting “R2”. Thanks for the reports…and all best wishes to you from California.