A new 2m barrier is broken. PY1MHZ- V51PJ QSO

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Tim Bucknall
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A new 2m barrier is broken. PY1MHZ- V51PJ QSO

Post by Tim Bucknall » 06 Oct 2016 11:57

http://d4c.cc/?p=12649

"Successful Bilateral Transatlantic 144 MHz QSO made !

Between 04 and 05 October 2016 a new record was set. PY1MHZ Marcos received in the city of Rio de Janeiro, Brasil from locator GG87JC the 2 m signal of V51PJ from locator JG82IE in Rosh Pinah, Namibia by using digital mode WSJT-X via Tropospheric ducting.

The distance between the two stations is 5987 km

Here the details of the records:
Frequency: 144.250MHz
Mode: WSJT-X – QRA64

Time and intensity:
04 OCT 2016 2038 UTC -37db at PY1MHZ

05 OCT 2016 0028 UTC -36db at V51PJ

Rig setup:
PY1MHZ 2x12el Horizontal polarity, 400W, Preamp 16db

V51PJ 2x13el Horizontal polarity, 1kW

Only thanks to the persistence and determination of these OM this historic achievement was possible.

We are all thankful to K1JT Joe Taylor that continuously provides to our community state of the art software.
"
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Tim Bucknall
Posts: 1690
Joined: 01 Oct 2014 14:55
Location: Congleton, often in the Peak District, sometimes in Poland or Kresy
Contact:

Re: A new 2m barrier is broken. PY1MHZ- V51PJ QSO

Post by Tim Bucknall » 07 Oct 2016 20:26

the've retracted their claim!!


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 European
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.

http://www.arrl.org/news/closer-look-re ... not-happen
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+ CLP 5130 Log P ant

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