Collection of various digital modes – images for now, maybe audio later. The idea here is to take waterfall screenshots in ‘real life’ environments, on a noisy waterfall, to serve as a reference on the software I use most often, fldigi.
These are all signals I received on my KX3, unless stated otherwise, and which I successfully decoded. This is a work in progress, I will add additional modes as I go along, so check back every once in a while! If there are modes you would like me to look for, let me know.
A fairly common practice is to use preambles to tell digital software what mode is going to be transmitted. There are mainly two types of preambles: “Reed Solomon ID” and video preamble. A good example of video preamble on a noisy waterfall can be found below:
More info on RSID can be found here: http://www.w1hkj.com/RSID_description.html
The usual suspect around 14.070MHz
A more sophisticated PSK with twice the speed, looks a bit wider on the waterfall:
A good example on 14.070 MHz:
Again, RSID is often used in the preamble. A zoom on the same signal:
DRM or “Digital Radio Mondiale”
A weird shortwave mode: digital shortwave radio. Not quite sure how much future there is with DRM, but you can still see it. Beautiful on the waterfall. You won’t be able to decode it using the audio output of a radio, because it has a bandwidth of 10kHz, so the IQ output of the radio will be necessary.
Captured at 11pm on 9.865 – the station was Radio New Zealand (RNZI). Very easy to decode using “Dream” and the KX3 IQ output.
Both signals below caught on 20m, just under 14.070 :
People usually use RSID at the beginning of transmissions to help out recognising signals, but it never hurts to see what this looks like on an actual waterfall.
Domino EX 4
More like little dots:
Note the settings on fldigi on the screenshot below: no “Rev” in particular;
More examples – same QSO, stronger signal from the other side, zoomed the waterfall too:
And last, the same signal on the much larger waterfall, still a distinctive visual signature:
Sitor is used for marine broadcasts. Around San Francisco, for instance, it can be found on 8.432 MHz.
Below is a very strong SITOR-B Signal: fairly narrow, but more dense than RTTY: