[VHFcontesting] FT4 and FT8 Contesting

Ed Muns ed at w0yk.com
Wed Feb 26 12:31:19 EST 2020



Ham radio communication uses an imperfect medium.  There is no way to guarantee message receipt by the two QSO partners.  This is the classic “Two Generals Paradox” discovered by the computer science community in 1972.


The practical mitigation is to use hints from the QSO context, e.g., did the other station ask for a repeat or go on to work another station.  CW, SSB and even RTTY have years of operator experience that learned the best “hints” to decide if a QSO is complete and should be logged. FT operation and contesting needs the same opportunity of experience to learn what those effective hints are since FT characteristics differ in several ways from the legacy modes/protocols.






From: John Kludt <johnnykludt at gmail.com> 
Sent: 26 February, 2020 09:13
To: ed at w0yk.com
Cc: VHF Contesting <vhfcontesting at contesting.com>
Subject: Re: [VHFcontesting] FT4 and FT8 Contesting




Interesting challenge.  There is also a follow-up email that suggests much of it is about operator training on how to use a new mode in a contest.   CW has been around for 100 years and SSB for 60 years so we kind of have those learning curves behind us.  





On Wed, Feb 26, 2020 at 12:03 PM Ed Muns <ed at w0yk.com <mailto:ed at w0yk.com> > wrote:

Log checking for several recent contests that used the FT4 and FT8 modes 
has shown undesirably large numbers of claimed QSOs that receive 
not-in-log ("NIL") status from the other station.  The WSJT development 
team has worked together with contest sponsors and log checkers to 
analyze the probable causes of these NILs.  Our findings and some 
operating advice for future contests are posted here:
and will also appear in the May-June 2020 issue of NCJ, the National 
Contest Journal.

        73 from the authors of the study:

        Steve Franke, K9AN
        Don Hill, AA5AU
        Ed Muns, W0YK
        Iztok Saje S52D
        Joe Taylor, K1JT

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