Ed, There is a strange anomaly that makes no sense yet many of us that (especially) work weak DX observe frequently ... Sometimes when you end up in a R -XX/RR73 loop ("RR/73 loop" or "ACK dance" as you term it) with a station anecdotally and observationally sometimes sending 73 sequences back manually appears to break the loop-cycle.
Why ? it makes no sense when logic is analysed or informed thought is applied to the observation. Note that it is not restricted to Weak DX - but is more often observed when both ends have desperation to complete the QSO. Yet from my direct observation, experimentation and simulation conducted a couple of back (when on "down time" with research that I was on - and using earlier on earlier FT8 releases and the "main fork") it is able to be replicated - yet inconsistently. There are "theories" that if the data stream is changed slightly then QRM/QRN effects that interact with signals passed over the decoder can change and therefore decoding impasses can be broken ... More likely the observation is just a statistical/probability anomaly. Yet some Amateurs SWEAR by this method to break impasses; I also admit that I have often found it to be observationally useful operationally to break a RR/73 loop ! A "revert and hold" over-ride over Tx4 sequencing when Tx5 is selected may be useful. Yet without mathematical or statistical justification for it - just observation and anecdote - it will be hard to convince the core developers of mitigation strategies that can and will consume valuable signal processing resources. 73 Steve I VK3VM / VK3SIR _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel