Software

[gandalf58]

Hi

Given the vast range of digital modes in use on HF is there any software that can identify digital signals in real time before you attempt to decode them or is it just down to listening to loads of audio signals until you get a feel for what you are listening to?

Also, which decoding software would the experts on here recommend for a newbie to digital signal decoding?

Many thanks

 

[ka3jjz]

This article from our wiki will get you started..

HF Digital Decoding - The RadioReference Wiki

Now how one determines modes is really a combination of several methods. Looking at the data waveform is certainly one, but there are those modes (like ALE) that are very distinctive and easy to spot. It's very much a learning curve, but eventually you get a feel for the general class of digital signal you are hearing and what mode it might be using. You can't really depend on software to do this for you, because noise and fading can fool such algorithms (unless you get to the VERY expensive decoders like W-Code, and even that can be fooled if the interference is heavy enough)

Another thing to keep in mind is that most folks that get into this heavily have several packages in their pocket, not just one. This is simply because the algorithms different packages use for decoding might not all work the same way, or even be the same. There are even some that interface directly with the receiver (what receiver do you plan on using?)

If it were me, just starting out, I'd get PC-ALE and MultiPSK. If you have one of the SDRs, it might be handy to have Sigmira on hand as well

This is not an easy area to get involved with - it takes a fair amount of study and trial/error before you learn how to handle this. And keep in mind that there are some signals we will never crack...Mike

 

[ka3jjz]

And let me see if I can anticipate your next question - where can I find frequencies?

For non-ham stuff, always keep an eye on the UDXF Yahoo group. Just keep in mind that as that's a world wide group, there are sigs you will never hear due to differences in propagation, just like on the broadcast side. The rules don't change just because the service does.

If there are other HF related groups or blogs where non-ham digital sig reports can be found (apart from the ones we already have in the wiki) feel free to jump in

Mike