Re: VLF: EbNaut transmissions on lower frequencies?, pre-tests: 6.47kHz

[DK7FC <selberdenken@posteo.de>]

Hello Paul,

Excellent, another very good result! :-)
But now, we are already at -0.2 dB. Would you think a 11 character 
message will decode? If the reference phase was constant, could we 
afford a 2 hour longer transmission time, e.g. 6...18 UTC?
Can you provide a bit error image (you know what i mean) for the last 
decode? It would be interesting to see how the errors are spread.
73, Stefan

Am 02.11.2016 20:57, schrieb Paul Nicholson:
> Stefan wrote:
>
> > f = 6470.00000 Hz
> > Start time: 02.11.2016 07:00:00 UTC
> > Symbol length: 30 s
> > Characters: 7
> > CRC 16
> > Coding 16K25A
> > Duration: 10h, 56m, 0s
> > Antenna current: ~ 280 mA
>
> Copied 'SUCCESS' at Eb/N0 = -0.2 dB BER 40.5%.
>
> Constant reference phase.
>
> Carrier S/N 15.5 dB in 25.4 uHz.
> -64.4 dB in 2500 Hz after sferic blanking.
>
> I was expecting to decode at about +1.2dB based on
> yesterday's S/N ratio. Today must have been a little
> noisier and I had to use a more aggressive blanker
> setting to maximise the Eb/N0.
>
> Uwe wrote:
>
> > EbNaut RX V0,4d tells me “Error: Not enough memory (trellis)”.
>
> You'll need a spare 22 GByte of RAM to decode this one.
>
> --
> Paul Nicholson
> --