I broadly enjoy the digital modes, especially RTTY, and have been using some FT8 outside of contests.
A signal power that FT8 reports as being at -15dB, is easily heard and copied by ear by any decent CW operator. I think a really good CW operator could pull (maybe with a few repeats) callsigns out at strengths that FT8 would classify as weaker than -20dB. This is a nice presentation about noise estimation in WSJT especially FT8: https://tapr.org/pdf/DCC2018-KC5RUO-TheReal-FT8-JT65-JT9=SNR.pdf The subject of noise bandwidth has come up several times and is important to how the digital mode guys "push" their newest modes. There's a lot of traps with this way of rating things, especially when you compare modes (like FT8) that allow no human smarts to improve copy, against other modes (like SSB, CW and in fact RTTY) that allow human smarts to improve copy. There was a SUPERB article in NCJ several years back by a ZS RTTY operator about all the tricks to use your brain to improve RTTY copy. But also note that there's a lot of reasons why an operator might not want to use a narrow filter for CW. Especially on the low bands, in the face of lightning crashes, many of us prefer to use wider bandwidths. In part this is because historically many rigs had narrow filters that rung like the dickens. (This was the trap of "shape factors" as a selling point for a few decades). But even with modern rigs with more optimal phase response a lot of us are more comfortable especially putting in long hours with wider rather than narrower filters. In VHF/UHF and EME weak-signal CW work, a lot of operators also liked listening with wider RX filters too, often preferring Gaussian filter shapes, and letting their ear pull the signal out of the noise. The psychoacoustics of listening to narrow bandwidths for extended periods leads to a lot of these preferences. There's an "acoustical paranoia" that sets in if you listen to noise too long with a narrow bandwidth and don't change things up (bandwidth, center frequency, something!) at least occasionally. When you find yourself in that paranoia it seems like the signal you are trying to hear is exactly the same shape and bandwidth of your narrow filter. And finally: one man's noise is another man's signal. Or even a Nobel prize. This is the story of how NBS scientists unintentionally discovered radio emissions from Jupiter by tracking down their noise source: https://www.nist.gov/news-events/news/2017/08/field-dreams Tim N3QE > > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector