Hello Stefan, VLF!
Yes!
Optimization of my receiving system yielded positive takes. Both 8-ch transmissions were successfully and quite easily decoded.
It is interesting that for transmission of March 07 of 22:30 best decode achiewed with small freq offset. Without this offset  was also successful decode but with smaller Eb/N0.
On reception only E-probe was used. I found that this setup, without Loop-ant, gives the best SNR in my environment.
Grabber is running and my next visit will at Monday.
Congrats to Stefan on his 8-char successful transmissions!

As usualy files are here:
http://rn3aus.narod.ru/ebnaut-vlf-7-9mar2017.zip 

ebnaut-rx V0.5
input file C:\EbNaut\ebnaut08_MAR_0448_8270-1pps.wav
sample rate 0.342935 per second
rx frequency 8270.1
file start time 2017-03-07 22:10:11.190
polynomial 16K21A
crc size 16
number of chars 8
block size 64
symbol period 30.000
number of symbols 1344
list length 200000
start offset 600.774
freq offset 0.000009
cores 2
skipped 600.696925 seconds to start
initial reference phase 19.0
---------------------------------------------
found CONGRATS
list rank 12
reference phase   30   30   30   30
carrier RMS 1.213e-004 noise RMS 1.783e-005
carrier S/N 16.65 dB in 24.8 uHz
carrier Es/N0 -14.63 dB
carrier Eb/N0 0.06 dB
info bit period 884.21 seconds
symbol error rate 532/1344 = 39.583 %
Es/N0 from symbol errors -14.5 dB
Eb/N0 from symbol errors 0.2 dB
Shannon capacity 5.9 bits/hour
Shannon efficiency 69.5 %
symbols file C:\EbNaut\ebnaut08_MAR_0448_8270-1pps-symbols.csv
elapsed 20 seconds

ebnaut-rx V0.5
input file C:\EbNaut\ebnaut09_MAR_2248_8270-1pps.wav
sample rate 0.342935 per second
rx frequency 8270.1
file start time 2017-03-09 16:10:11.190
polynomial 16K21A
crc size 16
number of chars 8
block size 64
symbol period 30.000
number of symbols 1344
list length 200000
start offset 6600.774
freq offset 0.000000
cores 1
skipped 6601.834167 seconds to start
initial reference phase 33.2
---------------------------------------------
found GOOD DAY
list rank 0
reference phase    0    0    0    0
carrier RMS 1.397e-004 noise RMS 1.888e-005
carrier S/N 17.39 dB in 24.8 uHz
carrier Es/N0 -13.90 dB
carrier Eb/N0 0.80 dB
info bit period 884.21 seconds
symbol error rate 546/1344 = 40.625 %
Es/N0 from symbol errors -15.5 dB
Eb/N0 from symbol errors -0.8 dB
Shannon capacity 6.9 bits/hour
Shannon efficiency 58.9 %
symbols file C:\EbNaut\ebnaut09_MAR_2248_8270-1pps-symbols.csv
elapsed 11 seconds