LF,

yesterday October 13, during daytime,  i had a very nice reception with low QRN/QRM floor. So i have invited Riccardo to send some EbNaut messages with 30 or 60 characters using a very short symbol period from 1 s to  0.05 s.

We had some positive decodes also with 60 characters and 0.05 s/sym:

 

2018-10-13_13:30:00 137490.000Hz N=60 T=0.05s 8K19A CRC=16 list=1000 sym=3152 Duration=157.60s
found rank 0 ber 2.1605e-01 Eb/N0 4.5 M -1.234827161e+00 ph 1 180,180,180,180
[TU DOM AND MARKUS FER HIGH BIT RATE EBN0 RPRT 73 DE IW4DXW K]

QRB between us is about 650 km.

The complete log of the test is listed in the website : https://www.qsl.net/iz7slz/EBNAUT/DECODED.TXT    from 09:30  to 15:00 UT of 2018-10-13.

Some messages have been decoded also by Markus DF6NM with his 'D' auto-decoder: http://df6nm.darc.de/opds/ebnautresults.txt

So,  it is possible to exchange on LF messages of 60 characters with less than 3 minute transmission. I think that 30 Characters at 0.1 s/symbol can be a good settings for a 'fast' QSO with 10 minutes timeslot : TX ends within 3 minutes, so, using an auto-decode program, should be possible to reply at next '10' minute.

73, Domenico IZ7SLZ