Hello VLF, Stefan
I'm glad to report about sucsessfull decode of 1-char ebnaut message sended on 5170.1 Hz 20,22,23 and 24 October.
Message was decoded by weighted stacking, unweighted stacking and from 23 okt file only. Other files give very poor decode with many false decodes or only false decodes.
In attacment we can see best decode from weighted stacking.
Also all ebnaut-files is available here: http://rn3aus.narod.ru/5170.zip
My VY congratulations to Stefan! Abt 2000 km on 5170 Hz!

ebnaut-rx V0.7a
input file sum.wav
sample rate 0.342935 per second
rx frequency 5170.1
file start time 2017-10-24 15:30:58.390
polynomial 8K19A
crc size 6
number of chars 1
block size 12
symbol period 180.000
number of symbols 240
list length 20
start offset 1754.000
freq offset 0.000000
cores 1
skipped 1755.434703 seconds to start
initial reference phase -27.5
---------------------------------------------
found =
list rank 0
reference phase    0    0    0    0
carrier S/N 12.10 dB in 23.1 uHz, -34.26 dB in 1Hz, -68.24 dB in 2.5kHz
carrier Es/N0 -11.70 dB
carrier Eb/N0 4.54 dB
info bit period 7578.95 seconds
symbol error rate 79/240 = 32.917 %
Es/N0 from symbol errors -10.0 dB
Eb/N0 from symbol errors 6.2 dB
Shannon capacity 1.9 bits/hour
Shannon efficiency 25.2 %
symbols file sum-symbols.csv
elapsed 2 seconds