Both stations should log the QSO when RR73 is sent. At that point in the message sequence both QSO partners have exchanged call signs, reports and acknowledgements (R -04 and RR73). No further messages need to be exchanged.
Rather than sending a third ACK, e.g., 73, to confirm receipt of the second ACK, e.g., RR73, instead re-send the first ACK message, e.g., R -04, only if you do not print the second ACK (RR73). Thus, absence of the re-send of R -04 is implicit confirmation the RR73 message was received. Furthermore, if the QSO partner sends CQ or calls another station in the next TX cycle, that is pretty solid confirmation that the RR73 was indeed received. This message sequence protocol has the advantage of both speed and clarity to both QSO partners about whether the QSO is complete and can be logged. No matter what message sequence protocol we use, the last message is always subject to loss. In the limit, the ACK dance could go on forever which takes more time for no benefit. If we agree and stick to a single message sequence protocol, then we can use that contextual information to determine QSO completion, by both QSO partners. The recommended message sequence is the same as has worked in the other modes for decades: exchange call signs, exchange parameters and ACKs (one each). The cordial practice of sending, or expecting, a 73 message as a third ACK to the RR73 message creates the inadvertent consequence of uncertainty about whether the other side is a "73 advocate" or not. 73, Ed W0YK -----Original Message----- From: Gary McDuffie <mcduf...@ag0n.net> Sent: 19 May, 2020 20:48 To: WSJT software development <wsjt-devel@lists.sourceforge.net> Subject: Re: [wsjt-devel] Clicking on RR73 produced wrong TX response msg > On May 19, 2020, at 10:05, Neil Zampella <ne...@techie.com> wrote: > > .. someone sending an RR73 does not expect a reply, the last 73 is a > courtesy from you the answering station. I certainly do, in order to let him know I got his RR73 and he needs to sen nothing else. If I don’t send 73, I expect him to repeat it because I obviously didn’t get his RR73 in the first place. When he gets my 73, he stops sending RR73, telling me that we are done! Gary - AG0N _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
