Locked Re: "TU; CALL2 report" seen in FT Roundup

Don Hill AA5AU

I didn't use WSJT-X in the contest. I used WriteLog and DigiRite. DigiRite has an option for the run station to send the ending "73" message. This is actually a "2nd confirmation" with the first confirmation being the "R" message that is originally sent to the answering station with the report. Some, including me, don't believe this 2nd confirmation is needed. But I do it to lower the NIL rate or at least to see if the NIL rate gets lowered. It may lower the NIL rate as seen by my NIL rate in the WW Digi contest in August. I think it was like 2% whereas the average across the board was higher than 5%.

The NIL rate for the FT Roundup is running right about 5% right now which is 2-3 points higher than CW and RTTY NIL rates.

I learned some additional information about the TU; message today. It appears only in the 77-bit format for the ARRL RTTY Roundup and it's been there since at least version 2.1. I don't know that the TU; message helps lower the NIL rate or not. We have no data to tell us. I just thought it was an interesting twist to the contest as I had not seen it before.

73, Don AA5AU

On Friday, December 11, 2020, 12:24:52 PM CST, ve3ki <ve3iay@...> wrote:

I agree with Steve. Following last weekend's contest I have already seen a surprising (to me) number of eQSL requests from people who are not in my log (about two orders of magnitude larger than what I see after a CW or RTTY contest). The most likely explanation is that I never copied an RR73 from them, I didn't log the contact because I had no way to know whether they had received my exchange, and they had no way to determine from my actions whether I had logged the contact, but they decided to do so anyway. In such situations (failing to receive an RR73), my practice during the contest was to repeat my sent exchange a couple more times, but if there was still no RR73 received, I had to decide whether I thought they had sent one or not and consequently whether to log the contact or not. Sometimes what I decided matched what they had done, and sometimes it didn't. I have no way yet to determine whether the rate of NILs in my log is going to be as high as the rate of NILs from me in other stations' logs, but at this point I have no strong reasons to believe they will be much different.

Don's sending of a 73 message was very helpful. Upon receiving that, the calling station knows for sure that the QSO was logged. A TU; next caller message also gives certainty that the contact was logged. In the absence of either of these, the calling station does not know for sure whether their RR73 message was received (completing the QSO and telling the CQing station to log the contact and move on directly to the next contact), or whether it was not received and the CQing station has simply given up on the attempted contact. If there were a common understanding on how many repeated tries is enough before giving up on a contact, that might help the decision-making, but as far as I know there is no such common understanding.

Even with an approach that requires either a 73 or a TU; next message at the end of a QSO, there would still be situations where a judgment call is required, but without either either of these, it seems to me that the level of ambiguity encountered during FT-mode contests is unnecessarily high as compared with other modes.

Rich VE3KI

On Fri, Dec 11, 2020 at 11:37 AM, Steve Kavanagh wrote:
I fully agree, Don.  Thanks for taking the time to send the 73 messages yourself this past weekend. Did you find a way to automate it or were you just quick on the buttons?  I noticed this TU thing happening some time go, and I even found myself sending it once or twice in an earlier contest (what exact conditions triggered it I still don't know).  But it needs to be there 100% of the time for running stations!

Steve VE3SMA

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