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Closer Look Reveals that Reported Transatlantic 2 Meter Contact Did Not Happen

10/07/2016

The reported transatlantic 2 meter contact between PY1MHZ in Brazil and V51PJ in Namibia turned out to be a false alarm, based on an incorrect interpretation of screen captures from the event — possibly the result of using an unreleased “development” version of the WSJT-X protocol’s QRA64 mode. As initially reported, extremely weak signals using QRA64 were received and decoded on both the African and South American ends of the path across the southern Atlantic. Screen captures of the protocol software were supplied to document the contact, but the software’s lead developer, Joe Taylor, K1JT, noticed debugging information, indicating that a prototype version of the protocol was being used. On closer inspection, the indicator values showed that the decodes were probably based on call sign information being known in advance, as is common with scheduled contacts.

“There was no intention to deceive,” Taylor told ARRL. “It was a perfectly honest mistake. It’s unfortunate. Many of us wish the report of such a QSO could be true — but it's not.”

Trying to complete a 2 meter contact over such distances is extremely challenging, and it remains to be accomplished. The Irish Radio Transmitters Society (IRTS) Brendan Awards, established to reward the first transatlantic contact in which one station is in Europe, are as yet unclaimed. Another false alarm occurred in 2015, when an apparent 2 meter contact between stations in Newfoundland and Ireland turned out to have been facilitated by reflections from the International Space Station, which was in low-Earth orbit above the midpoint of the signal path at the time.

The WSJT software suite includes several digital modes that are designed to work at extremely low signal-to-noise ratios — such as JT65, JT9, and WSPR. The QRA64 mode —developed by Nico Palermo, IV3NWV, in collaboration with Taylor — has been incorporated into the WSJT-X digital suite The protocol has several levels of decoding for which it can use previously available information such as call signs to confirm a match with information from the received signal. Decoding quality is most robust when no previously available information is required to make a successful decode.

This appears to simply be an honest error by both stations who deserve credit for an extraordinary effort and who have pledged to keep trying.

“V51PJ and PY1MHZ have put a big effort into seeing their dream of a transatlantic 2 meter QSO come true,” Taylor said. “They deserve a lot of credit for what they have done.”

Pieter Jacobs, V51PJ, said the effort to complete a contact is a work in progress. “Conditions are ever changing on this long stretch of water, so we are still trying,” he told ARRL.



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